{"product_id":"low-dose-aspirin-after-colorectal-cancer-surgery-new-hope-for-patients-with-pi3k-gene-changes","title":"Low-Dose Aspirin After Colorectal Cancer Surgery: New Hope for Patients with PI3K Gene Changes","description":"\u003cp\u003eIn a landmark clinical trial published in the \u003cem\u003eNew England Journal of Medicine\u003c\/em\u003e, researchers found that taking a daily 160 mg dose of aspirin for three years after colorectal cancer surgery cut the risk of cancer recurrence roughly in half for patients whose tumors carried specific genetic alterations in the PI3K signaling pathway. Among patients with PIK3CA hotspot mutations, the 3-year recurrence rate was 7.7% with aspirin versus 14.1% with placebo—a statistically significant difference (hazard ratio [HR], 0.49; 95% confidence interval [CI], 0.24 to 0.98; P = 0.04). This study, called ALASCCA (Adjuvant Low-Dose Aspirin in Colorectal Cancer), is the first randomized, placebo-controlled trial to confirm what earlier observational studies had suggested: that this inexpensive and widely available medication may become a valuable addition to colorectal cancer treatment—but only for patients whose tumors have specific genetic features.\u003c\/p\u003e\n\n\u003ch1\u003eLow-Dose Aspirin After Colorectal Cancer Surgery: New Hope for Patients with PI3K Gene Changes\u003c\/h1\u003e\n\n\u003ch2\u003eTable of Contents\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003e\u003ca href=\"#ddn-key-points\"\u003eKey Points\u003c\/a\u003e\u003c\/li\u003e\n\n  \u003cli\u003e\u003ca href=\"#background\"\u003eUnderstanding the Research\u003c\/a\u003e\u003c\/li\u003e\n  \u003cli\u003e\u003ca href=\"#why\"\u003eWhy This Study Was Needed\u003c\/a\u003e\u003c\/li\u003e\n  \u003cli\u003e\u003ca href=\"#methods\"\u003eHow the Study Was Conducted\u003c\/a\u003e\u003c\/li\u003e\n  \u003cli\u003e\u003ca href=\"#patients\"\u003eWho Was in the Study\u003c\/a\u003e\u003c\/li\u003e\n  \u003cli\u003e\u003ca href=\"#findings\"\u003eKey Findings: What the Researchers Discovered\u003c\/a\u003e\u003c\/li\u003e\n  \u003cli\u003e\u003ca href=\"#safety\"\u003eSafety and Side Effects\u003c\/a\u003e\u003c\/li\u003e\n  \u003cli\u003e\u003ca href=\"#implications\"\u003eWhat This Means for Patients\u003c\/a\u003e\u003c\/li\u003e\n  \u003cli\u003e\u003ca href=\"#limitations\"\u003eStudy Limitations\u003c\/a\u003e\u003c\/li\u003e\n  \u003cli\u003e\u003ca href=\"#recommendations\"\u003eRecommendations for Patients\u003c\/a\u003e\u003c\/li\u003e\n  \u003cli\u003e\u003ca href=\"#ddn-faq\"\u003eFrequently Asked Questions\u003c\/a\u003e\u003c\/li\u003e\n\u003cli\u003e\u003ca href=\"#source\"\u003eSource Information\u003c\/a\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003c!-- ddn:keypoints:start --\u003e\n\u003ch2 id=\"ddn-key-points\"\u003eKey Points\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003eIn the ALASCCA randomized trial, 160 mg aspirin daily for three years roughly halved colorectal cancer recurrence in patients with PI3K pathway–altered tumors.\u003c\/li\u003e\n\u003cli\u003eAmong PIK3CA hotspot mutation patients, three-year recurrence was 7.7% with aspirin versus 14.1% with placebo.\u003c\/li\u003e\n\u003cli\u003eSevere adverse events occurred in 16.8% of aspirin recipients versus 11.6% of placebo recipients, mainly bleeding risks.\u003c\/li\u003e\n\u003cli\u003eTumor genetic testing for PIK3CA, PIK3R1, and PTEN can identify whether a patient might benefit from aspirin after surgery.\u003c\/li\u003e\n\u003cli\u003eAspirin should only be started on your oncology team's advice and is not a replacement for standard surgery, chemotherapy, or surveillance.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c!-- ddn:keypoints:end --\u003e\n\n\n\u003ch2 id=\"background\"\u003eUnderstanding the Research\u003c\/h2\u003e\n\n\u003cp\u003eColorectal cancer remains a major global health burden, with approximately \u003cstrong\u003e1.9 million new cases diagnosed annually\u003c\/strong\u003e worldwide. Despite advances in surgical techniques, radiation therapy, and systemic drug treatments, recurrence rates remain substantial—\u003cstrong\u003emetastatic recurrence (cancer that spreads to other organs) develops in 30 to 40% of patients\u003c\/strong\u003e even after apparently successful treatment.\u003c\/p\u003e\n\n\u003cp\u003eAspirin is one of the most extensively studied and widely used medications in the world. It has well-established pain-relieving (analgesic), anti-inflammatory, and heart-protective (cardioprotective) effects. In recent years, however, emerging evidence has suggested that aspirin may also play an important role in \u003cstrong\u003ecancer prevention, particularly in colorectal cancer\u003c\/strong\u003e.\u003c\/p\u003e\n\n\u003cp\u003eBoth laboratory (preclinical) and clinical studies have shown that aspirin reduces the incidence of colorectal adenomas (precancerous polyps) and colorectal cancer itself, especially among high-risk individuals with hereditary colorectal cancer syndromes, such as Lynch syndrome. In addition, some studies have reported that using aspirin \u003cem\u003eafter\u003c\/em\u003e a colorectal cancer diagnosis is associated with improvements in both disease-free survival (time without cancer returning) and overall survival.\u003c\/p\u003e\n\n\u003cp\u003eHowever, the results across studies have been inconsistent. This inconsistency has led researchers to suspect that the benefit of aspirin may not apply to everyone, but rather may be \u003cstrong\u003erestricted to molecularly defined subgroups\u003c\/strong\u003e—that is, patients whose tumors have certain specific genetic mutations.\u003c\/p\u003e\n\n\u003ch2 id=\"why\"\u003eWhy This Study Was Needed\u003c\/h2\u003e\n\n\u003cp\u003eTo understand the science behind this trial, it helps to know a little about how aspirin and certain gene changes interact. The anti-cancer effects of aspirin are believed to work primarily through the inhibition of an enzyme called \u003cstrong\u003ecyclooxygenase-2 (COX-2)\u003c\/strong\u003e, which is frequently overproduced (overexpressed) in colorectal cancer. COX-2 promotes tumor growth by increasing the production of a substance called \u003cstrong\u003eprostaglandin E2 (PGE2)\u003c\/strong\u003e, which then activates a cellular signaling pathway known as the \u003cstrong\u003ePI3K (phosphatidylinositol 3-kinase) pathway\u003c\/strong\u003e—a chain of molecular events inside cells that controls cell growth, division, and survival.\u003c\/p\u003e\n\n\u003cp\u003eHere is where the genetics come in: the PI3K pathway is genetically altered in approximately \u003cstrong\u003eone third of colorectal cancers\u003c\/strong\u003e. These alterations most commonly involve mutations in three genes: \u003cstrong\u003ePIK3CA\u003c\/strong\u003e, \u003cstrong\u003ePIK3R1\u003c\/strong\u003e, and \u003cstrong\u003ePTEN\u003c\/strong\u003e.\u003c\/p\u003e\n\n\u003cp\u003eLaboratory and retrospective clinical data suggest that COX-2 may be a critical downstream \"effector\" of tumors with PIK3CA mutations—meaning that these mutated tumors rely heavily on COX-2 activity, making them particularly sensitive to aspirin's effects. This sensitivity is potentially driven by a positive feedback loop between PI3K signaling and COX-2 expression, where each activates the other, creating a cycle that aspirin can interrupt.\u003c\/p\u003e\n\n\u003cp\u003eSeveral observational studies (studies that observe patients without randomly assigning treatments) have shown that aspirin improves survival among patients with PIK3CA-mutated tumors but offers \u003cstrong\u003eno benefit in patients whose tumors do not carry these mutations (wild-type tumors)\u003c\/strong\u003e. However, given the variability in existing clinical and experimental findings, researchers knew that a rigorous randomized controlled trial was urgently needed to establish whether this benefit was real. The ALASCCA trial was designed specifically to answer that question.\u003c\/p\u003e\n\n\u003ch2 id=\"methods\"\u003eHow the Study Was Conducted\u003c\/h2\u003e\n\n\u003cp\u003eThe ALASCCA trial was a \u003cstrong\u003eregistry-based, multinational, double-blind, randomized, placebo-controlled trial\u003c\/strong\u003e. Let's unpack what that means in plain language:\u003c\/p\u003e\n\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003eRegistry-based:\u003c\/strong\u003e The trial was integrated into the Swedish Colorectal Cancer Registry, a national database tracking cancer patients.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eMultinational:\u003c\/strong\u003e It was conducted at \u003cstrong\u003e33 hospitals across four Nordic countries\u003c\/strong\u003e: Sweden, Norway, Denmark, and Finland.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eDouble-blind:\u003c\/strong\u003e Neither the patients nor their doctors knew who was receiving aspirin versus placebo (an inactive sugar pill).\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eRandomized, placebo-controlled:\u003c\/strong\u003e Patients were assigned by chance (like flipping a coin) to receive either aspirin or a matched placebo, ensuring that the two groups were comparable.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eThe trial enrolled \u003cstrong\u003epatients 18 to 80 years of age\u003c\/strong\u003e who had undergone radical (complete) surgical removal of their tumor and had either:\u003c\/p\u003e\n\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003eStage II or III colon cancer\u003c\/strong\u003e (cancer of the large intestine), or\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eStage I, II, or III rectal cancer\u003c\/strong\u003e (cancer of the rectum, the last section of the large intestine)\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eCancer stage was assessed using the standard AJCC (American Joint Committee on Cancer) Cancer Staging Manual, 7th edition. Crucially, all patients' tumor tissue was genetically screened for specific mutations. Patients were eligible only if their tumors carried what the researchers defined as \"PI3K pathway alterations,\" divided into two groups:\u003c\/p\u003e\n\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003eGroup A alterations:\u003c\/strong\u003e Prespecified hotspot mutations (well-known, specific mutation sites) in exons 9 and 20 of the PIK3CA gene.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eGroup B alterations:\u003c\/strong\u003e Other moderate- or high-impact genetic variants in PIK3CA, PIK3R1, or PTEN—mutations with varying degrees of functional effect on the protein they encode.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003ePatients who had both Group A and Group B alterations were counted in the Group A cohort. The genomic profile was assessed using a custom assay developed specifically for this trial, testing both tumor tissue and whole blood samples.\u003c\/p\u003e\n\n\u003cp\u003eEligible patients were randomly assigned in a \u003cstrong\u003e1:1 ratio\u003c\/strong\u003e to receive either \u003cstrong\u003e160 mg of aspirin\u003c\/strong\u003e or a \u003cstrong\u003ematched placebo\u003c\/strong\u003e once daily for \u003cstrong\u003e3 years\u003c\/strong\u003e. For context, 160 mg of aspirin is considered a low dose—lower than a standard pain-relief dose (typically 325–500 mg) but higher than the 81 mg \"baby aspirin\" commonly used for heart protection in the United States. Treatment began \u003cstrong\u003ewithin 12 weeks after surgery\u003c\/strong\u003e.\u003c\/p\u003e\n\n\u003cp\u003ePatients could also receive adjuvant chemotherapy (chemotherapy given after surgery to eliminate any remaining cancer cells) chosen by their local investigator according to each country's national treatment guidelines, administered alongside the aspirin or placebo.\u003c\/p\u003e\n\n\u003cp\u003eRandomization was stratified (balanced) according to three factors: tumor location (colon or rectum), cancer stage (I, II, or III), and genetic alteration group (A or B). Patients were recruited from \u003cstrong\u003eApril 6, 2016, through July 19, 2021\u003c\/strong\u003e. Follow-up evaluations were conducted every 3 months, either in person or by telephone.\u003c\/p\u003e\n\n\u003cp\u003eSurveillance for cancer recurrence included thoracic (chest) and abdominal computed tomography (CT) or magnetic resonance imaging (MRI), following national guidelines that recommend imaging at \u003cstrong\u003e1 year and 3 years after surgery\u003c\/strong\u003e. Any suspected recurrence was evaluated at the local investigator's discretion. Adherence (whether patients actually took their assigned pills) was monitored through pill counts at clinic visits and patient-reported adherence during telephone follow-ups.\u003c\/p\u003e\n\n\u003ch3\u003eTrial Oversight and Governance\u003c\/h3\u003e\n\n\u003cp\u003eAn independent data and safety monitoring committee reviewed safety data twice a year (biannually). The trial protocol was approved by the Swedish Ethical Review Authority and local ethics committees at each trial site or in each participating country. All patients provided written informed consent. The study was funded by the Swedish Research Council and other organizations. Notably, \u003cstrong\u003ePfizer provided the aspirin free of charge but had no role\u003c\/strong\u003e in the design of the trial protocol or the conduct of the trial—eliminating industry bias in how the study was run.\u003c\/p\u003e\n\n\u003ch3\u003eWhat the Researchers Measured\u003c\/h3\u003e\n\n\u003cp\u003eThe \u003cstrong\u003eprimary end point\u003c\/strong\u003e (the main question the study was designed to answer) was \u003cstrong\u003ecolorectal cancer recurrence\u003c\/strong\u003e—defined as locoregional recurrence (cancer returning near the original site), distant metastasis (cancer spreading to other organs), or death from colorectal cancer—assessed specifically in patients with Group A alterations, using a time-to-event analysis (measuring how long until recurrence occurred).\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eSecondary end points\u003c\/strong\u003e included:\u003c\/p\u003e\n\n\u003cul\u003e\n  \u003cli\u003eColorectal cancer recurrence in patients with Group B alterations\u003c\/li\u003e\n  \u003cli\u003eDisease-free survival (time from randomization to first occurrence of locoregional recurrence, distant metastasis, any new primary cancer, or death from any cause)\u003c\/li\u003e\n  \u003cli\u003eOverall survival (time from randomization to death from any cause)\u003c\/li\u003e\n  \u003cli\u003eAdverse events and severe adverse events\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003e\u003cstrong\u003eSevere adverse events\u003c\/strong\u003e were defined as grade 3 or higher according to the National Cancer Institute Common Terminology Criteria for Adverse Events, version 4.0—meaning serious, medically significant events that may require hospitalization or be life-threatening.\u003c\/p\u003e\n\n\u003cp\u003eThe original sample-size calculation estimated that \u003cstrong\u003e204 aspirin recipients and 204 placebo recipients with Group A alterations\u003c\/strong\u003e would provide 80% power to detect a hazard ratio of 0.5 for disease recurrence by year 3, assuming a 25% recurrence rate in the placebo group. This calculation was \u003cstrong\u003eupdated in 2020\u003c\/strong\u003e based on the actual distribution of cancer stages among enrolled patients. The updated calculation estimated that \u003cstrong\u003e150 patients per group\u003c\/strong\u003e would provide 80% power to detect a hazard ratio of 0.36, assuming an 18% recurrence rate by year 3 in the placebo group.\u003c\/p\u003e\n\n\u003ch2 id=\"patients\"\u003eWho Was in the Study\u003c\/h2\u003e\n\n\u003cp\u003eThe study screened a very large population. Here is the step-by-step enrollment journey:\u003c\/p\u003e\n\n\u003col\u003e\n  \u003cli\u003e\n\u003cstrong\u003e13,178 patients\u003c\/strong\u003e aged 18–80 years with clinical stage I, II, or III colorectal cancer and planned curative abdominal surgery were eligible for prescreening.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003e6,397 patients\u003c\/strong\u003e were assessed for eligibility; 2,614 were excluded (2,203 did not meet eligibility criteria; 411 declined to participate).\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003e3,783 patients\u003c\/strong\u003e provided written informed consent and had tumor and blood samples obtained during surgery for molecular screening.\u003c\/li\u003e\n  \u003cli\u003eOf these, 2,680 were excluded: \u003cstrong\u003e1,877 had no somatic alterations in PI3K pathway genes\u003c\/strong\u003e, 530 could not have their PI3K alteration status determined, and 273 did not have molecular screening performed.\u003c\/li\u003e\n  \u003cli\u003eThis left \u003cstrong\u003e1,103 patients (37.0%)\u003c\/strong\u003e with PI3K pathway alterations out of \u003cstrong\u003e2,980 patients with complete genomic data\u003c\/strong\u003e.\u003c\/li\u003e\n\u003c\/ol\u003e\n\n\u003cp\u003eAmong these 1,103 patients, \u003cstrong\u003e515 (17.3%) had Group A alterations\u003c\/strong\u003e (PIK3CA hotspot mutations in exon 9 or 20), and \u003cstrong\u003e588 (19.7%) had Group B alterations\u003c\/strong\u003e (other variants in PIK3CA, PIK3R1, or PTEN).\u003c\/p\u003e\n\n\u003cp\u003eAfter reassessing eligibility criteria following surgery:\u003c\/p\u003e\n\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003e314 patients with Group A alterations\u003c\/strong\u003e were randomly assigned: 157 to aspirin, 157 to placebo.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003e312 patients with Group B alterations\u003c\/strong\u003e were randomly assigned: 156 to aspirin, 156 to placebo.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eIn the safety analysis (patients who actually received at least one dose of their assigned treatment), there were 155 aspirin recipients and 156 placebo recipients in Group A, and 154 aspirin recipients and 155 placebo recipients in Group B. Only a very small number of patients (1–2 in each group) were lost to follow-up.\u003c\/p\u003e\n\n\u003cp\u003eBaseline characteristics were generally well balanced between the groups. Here is a profile of the 626 randomized patients:\u003c\/p\u003e\n\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003e51.8% were women\u003c\/strong\u003e (324 patients)\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003e33.1% had rectal cancer\u003c\/strong\u003e (207 patients)\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eMedian age: 66 years\u003c\/strong\u003e (range, 31 to 80)\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eMedian time from surgery to randomization: 7.7 weeks\u003c\/strong\u003e (range, 1.6 to 23.3)\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003e91.7%\u003c\/strong\u003e of patients (574 patients) were randomized within 12 weeks after surgery\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eAdditional molecular testing of the randomized patients revealed important tumor characteristics:\u003c\/p\u003e\n\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003eMicrosatellite instability-high (MSI-High)\u003c\/strong\u003e—a marker of a specific type of genetic instability—was found in \u003cstrong\u003e145 of 530 patients (27.4%)\u003c\/strong\u003e.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eBRAF V600E mutation\u003c\/strong\u003e (a common cancer-driving mutation) was present in \u003cstrong\u003e140 of 552 patients (25.4%)\u003c\/strong\u003e.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eKRAS mutation\u003c\/strong\u003e (another common cancer gene mutation) was present in \u003cstrong\u003e288 of 579 patients (49.7%)\u003c\/strong\u003e.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eNRAS mutation\u003c\/strong\u003e was present in \u003cstrong\u003e27 of 540 patients (5.0%)\u003c\/strong\u003e.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eAdherence to the study regimen—defined as taking at least 80% of assigned doses—was \u003cstrong\u003e66.1% in the aspirin group\u003c\/strong\u003e (207 of 313 patients) and \u003cstrong\u003e70.3% in the placebo group\u003c\/strong\u003e (220 of 313 patients). Adherence was slightly higher in men (69.9%) than in women (66.7%).\u003c\/p\u003e\n\n\u003ch2 id=\"findings\"\u003eKey Findings: What the Researchers Discovered\u003c\/h2\u003e\n\n\u003ch3\u003eThe Primary End Point: Recurrence in Patients with Group A Alterations\u003c\/h3\u003e\n\n\u003cp\u003eThe most important finding of the trial was dramatic: among patients with Group A alterations (PIK3CA hotspot mutations in exon 9 or 20), the estimated \u003cstrong\u003e3-year cumulative incidence of colorectal cancer recurrence was 7.7% with aspirin, compared with 14.1% with placebo\u003c\/strong\u003e.\u003c\/p\u003e\n\n\u003cp\u003eThis means that aspirin reduced the risk of recurrence by about half. The hazard ratio was \u003cstrong\u003e0.49\u003c\/strong\u003e (95% confidence interval [CI], 0.24 to 0.98; P = 0.04). In plain language, this means that patients taking aspirin were 51% less likely to experience a recurrence during the follow-up period than those taking placebo.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhat does the P value mean?\u003c\/strong\u003e A P value of 0.04 means there is only a 4% probability that this result occurred by random chance. In medical research, a P value below 0.05 (5%) is considered statistically significant—meaning the result is likely to be a real effect, not luck.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhat does the confidence interval mean?\u003c\/strong\u003e The 95% confidence interval of 0.24 to 0.98 represents the range of plausible values for the true effect. Because the entire range is below 1.0 (with the upper boundary barely touching 0.98), this confirms that aspirin is consistently associated with a reduced recurrence risk, though the precise magnitude of benefit could range from a 2% reduction to a 76% reduction.\u003c\/p\u003e\n\n\u003ch3\u003eSecondary End Points\u003c\/h3\u003e\n\n\u003cp\u003eThe researchers also examined outcomes in patients with Group B alterations (other mutations in PIK3CA, PIK3R1, or PTEN), and the results were similarly encouraging:\u003c\/p\u003e\n\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003eRecurrence in Group B patients:\u003c\/strong\u003e The estimated 3-year cumulative incidence of recurrence was \u003cstrong\u003e7.7% with aspirin versus 16.8% with placebo\u003c\/strong\u003e, corresponding to a hazard ratio of \u003cstrong\u003e0.42\u003c\/strong\u003e (95% CI, 0.21 to 0.83)—a 58% relative risk reduction.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eDisease-free survival in Group A patients:\u003c\/strong\u003e The estimated 3-year disease-free survival rate was \u003cstrong\u003e88.5% with aspirin versus 81.4% with placebo\u003c\/strong\u003e (hazard ratio, 0.61; 95% CI, 0.34 to 1.08). While the hazard ratio favored aspirin, the confidence interval includes 1.0, meaning this particular result did not reach conventional statistical significance.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eDisease-free survival in Group B patients:\u003c\/strong\u003e The estimated 3-year disease-free survival rate was \u003cstrong\u003e89.1% with aspirin versus 78.7% with placebo\u003c\/strong\u003e, corresponding to a hazard ratio of \u003cstrong\u003e0.51\u003c\/strong\u003e (95% CI, 0.29 to 0.88)—this result \u003cem\u003ewas\u003c\/em\u003e statistically significant.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eIt is worth emphasizing that the recurrence findings in both groups were remarkably consistent: aspirin roughly halved the recurrence risk regardless of whether patients had the specific PIK3CA hotspot mutations (Group A) or other PI3K pathway alterations (Group B). The disease-free survival results also favored aspirin in both groups, with the Group B result reaching statistical significance.\u003c\/p\u003e\n\n\u003cp\u003eThe researchers noted that the secondary end point analyses were descriptive and did not include adjustments for multiple comparisons—meaning these results, while strongly suggestive, should be interpreted with some caution.\u003c\/p\u003e\n\n\u003ch2 id=\"safety\"\u003eSafety and Side Effects\u003c\/h2\u003e\n\n\u003cp\u003eBecause aspirin is a blood thinner, it carries known risks, particularly gastrointestinal bleeding and bleeding in other parts of the body. The trial therefore carefully tracked adverse events.\u003c\/p\u003e\n\n\u003cp\u003eThe key safety finding: \u003cstrong\u003eSevere adverse events occurred in 16.8% of aspirin recipients and 11.6% of placebo recipients\u003c\/strong\u003e. This means that patients taking aspirin had a somewhat higher rate of serious side effects—about 5 percentage points higher. While the absolute numbers are not enormous, this difference matters and highlights the importance of doctors weighing the benefits of recurrence prevention against the potential risks of bleeding and other serious complications in each individual patient.\u003c\/p\u003e\n\n\u003cp\u003eAdverse events were carefully assessed in the safety population (all patients who received at least one container of aspirin or placebo). Events were graded according to standardized criteria, and local investigators who were unaware of treatment assignments evaluated them initially, with the principal investigator confirming them after the trial group assignments were revealed—a safeguard to ensure unbiased reporting.\u003c\/p\u003e\n\n\u003ch2 id=\"implications\"\u003eWhat This Means for Patients\u003c\/h2\u003e\n\n\u003cp\u003eThis study is genuinely practice-changing for several reasons. First, it provides the \u003cstrong\u003efirst randomized, placebo-controlled evidence\u003c\/strong\u003e that aspirin can reduce colorectal cancer recurrence in a genetically selected patient population. Prior to ALASCCA, the evidence for aspirin's benefit in PIK3CA-mutated colorectal cancer came mainly from observational studies, which can be influenced by various biases. This trial's rigorous double-blind, randomized design provides much stronger evidence.\u003c\/p\u003e\n\n\u003cp\u003eSecond, the treatment is remarkably \u003cstrong\u003esimple, inexpensive, and accessible\u003c\/strong\u003e. Aspirin is available over the counter worldwide at very low cost. If confirmed by additional research, this could offer an affordable treatment option for colorectal cancer patients in both high-income and low-income countries.\u003c\/p\u003e\n\n\u003cp\u003eThird, the study reinforces the concept of \u003cstrong\u003eprecision medicine\u003c\/strong\u003e—matching treatments to the genetic characteristics of an individual patient's tumor. Nearly 40% of patients in the trial (37.0%) had PI3K pathway alterations in their tumors, meaning a very substantial proportion of colorectal cancer patients could potentially benefit from this approach if genetic testing becomes part of routine care.\u003c\/p\u003e\n\n\u003cp\u003eFourth, there are possible broader implications. The finding that aspirin's benefit appears to extend to a wider range of PI3K pathway alterations (Group B), not just the specific PIK3CA hotspot mutations (Group A), suggests that the population of potentially eligible patients could be even larger than initially thought. However, the secondary nature of the Group B analyses means this requires confirmation.\u003c\/p\u003e\n\n\u003cp\u003eThe authors concluded that aspirin led to a \u003cstrong\u003esignificantly lower incidence of colorectal cancer recurrence than placebo\u003c\/strong\u003e among patients with PIK3CA hotspot mutations in exon 9 or 20 (Group A) and appeared to have a similar benefit among those with other somatic alterations in PI3K pathway genes (Group B).\u003c\/p\u003e\n\n\u003ch2 id=\"limitations\"\u003eStudy Limitations\u003c\/h2\u003e\n\n\u003cp\u003eLike all medical research, this trial has important limitations that should be acknowledged:\u003c\/p\u003e\n\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003eAdherence was imperfect:\u003c\/strong\u003e Only 66.1% of aspirin recipients and 70.3% of placebo recipients took at least 80% of their assigned doses. This means some patients did not receive the full potential benefit, and the true treatment effect might be larger or smaller than observed depending on how adherence is analyzed.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eSecondary end points were not adjusted for multiplicity:\u003c\/strong\u003e The results for Group B alterations and disease-free survival are described as descriptive, meaning they did not undergo the same rigorous statistical controls as the primary end point. While the results are strongly encouraging, they should not yet be treated as definitive.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eLimited diversity of participants:\u003c\/strong\u003e The authors noted that Black patients were underrepresented in the trial, which may limit the generalizability of the findings to all populations.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eDuration of follow-up:\u003c\/strong\u003e The primary analysis focused on 3-year recurrence and disease-free survival. Colorectal cancer can recur later than 3 years after surgery, and the trial's 5-year overall survival data were still being collected when the primary results were reported.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eSample size in subgroup analyses:\u003c\/strong\u003e The trial was powered primarily for the Group A analysis, and subgroups defined by cancer stage, tumor location, and other factors had relatively small numbers of patients, making those subgroup analyses less reliable.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eThe \"number needed to treat\" varies:\u003c\/strong\u003e While the relative risk reduction (~50%) was dramatic, the absolute benefit depends on a patient's baseline risk. The authors calculated the 3-year number needed to treat (NNT)—the number of patients who need to be treated to prevent one recurrence—according to cancer stage and tumor location. For lower-risk patients, more patients may need to be treated to prevent one recurrence, while for higher-risk patients, fewer.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2 id=\"recommendations\"\u003eRecommendations for Patients\u003c\/h2\u003e\n\n\u003cp\u003eBased on this study, here is what patients should know and discuss with their oncology team:\u003c\/p\u003e\n\n\u003col\u003e\n  \u003cli\u003e\n\u003cstrong\u003eDo not start taking aspirin on your own:\u003c\/strong\u003e This trial tested a specific dose (160 mg daily) in a specific patient population (those with PI3K pathway alterations). Not all colorectal cancer patients have these genetic changes, and aspirin carries real bleeding risks. Your cancer care team is the right person to determine whether aspirin might be appropriate for you.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eAsk about genetic testing of your tumor:\u003c\/strong\u003e If you have been diagnosed with colorectal cancer, ask your doctor whether your tumor has been or could be tested for PIK3CA, PIK3R1, and PTEN mutations. This information can help determine whether you might be one of the roughly one-third of patients whose tumors carry PI3K pathway alterations.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eConsider the risk-benefit balance:\u003c\/strong\u003e While aspirin reduced recurrence risk dramatically, severe adverse events occurred in 16.8% of aspirin recipients compared with 11.6% of placebo recipients. Discuss your personal risk of bleeding (including any history of ulcers, bleeding disorders, or use of other blood-thinning medications) with your doctor.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eUnderstand that this is one study:\u003c\/strong\u003e While the results are promising and statistically significant for the primary end point, the medical community will want to see confirmatory trials before aspirin becomes a standard recommendation. Stay informed and ask your doctor whether any follow-up studies have been published.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eMaintain adherence if prescribed:\u003c\/strong\u003e If your doctor does recommend aspirin, taking it consistently matters. The trial found that recurrence rates were dramatically lower with aspirin, and the benefit depends on actually taking the medication as prescribed (at least 80% of doses).\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eRemember the basics still apply:\u003c\/strong\u003e Aspirin, if recommended, would be an addition to—not a replacement for—standard treatments including surgery, chemotherapy when indicated, and regular surveillance imaging at 1 and 3 years after surgery.\u003c\/li\u003e\n\u003c\/ol\u003e\n\n\u003cp\u003eIn summary, the ALASCCA trial provides the strongest evidence to date that a simple, inexpensive daily aspirin tablet can meaningfully reduce the risk of colorectal cancer recurrence in patients whose tumors carry PI3K pathway mutations. For these patients, the future of post-surgical care may soon include this widely available medication—a powerful example of how genetic testing can unlock the full potential of established drugs.\u003c\/p\u003e\n\n\u003c!-- ddn:faq:start --\u003e\n\u003ch2 id=\"ddn-faq\"\u003eFrequently Asked Questions\u003c\/h2\u003e\n\u003ch3\u003eShould I take aspirin after colorectal cancer surgery to lower the chance of recurrence?\u003c\/h3\u003e\n\u003cp\u003eNot on your own. In the ALASCCA trial, 160 mg aspirin daily for three years roughly halved recurrence risk in patients whose tumors had PI3K pathway alterations, especially PIK3CA hotspot mutations. But aspirin has bleeding risks. Ask your oncology team whether genetic testing and aspirin might be appropriate for your situation.\u003c\/p\u003e\n\u003ch3\u003eHow can I find out if my colorectal tumor has the gene changes that aspirin might help?\u003c\/h3\u003e\n\u003cp\u003eAsk your doctor about testing tumor tissue for mutations in PIK3CA, PIK3R1, and PTEN. In the trial, specialized genetic screening identified PI3K pathway alterations in 37% of patients with complete genomic data. Testing your tumor can show whether you are part of the group that might benefit from aspirin after surgery.\u003c\/p\u003e\n\u003ch3\u003eWhat risks should I consider before taking daily aspirin after colorectal cancer surgery?\u003c\/h3\u003e\n\u003cp\u003eAspirin is a blood thinner and can cause serious bleeding. In the trial, severe adverse events occurred in 16.8% of aspirin recipients versus 11.6% of placebo recipients. Your doctor will weigh your personal bleeding history, ulcers, or other blood thinners against the potential recurrence prevention benefit before recommending aspirin.\u003c\/p\u003e\n\u003ch3\u003eDoes aspirin help every colorectal cancer patient, or only some?\u003c\/h3\u003e\n\u003cp\u003eOnly patients whose tumors carry specific PI3K pathway alterations appeared to benefit in the ALASCCA trial. About one-third of colorectal cancers have these mutations. The trial enrolled only patients with these gene changes. For others, aspirin did not show the same effect and carries risks, so it is not for everyone.\u003c\/p\u003e\n\u003ch3\u003eWhat dose of aspirin was tested, and for how long after surgery?\u003c\/h3\u003e\n\u003cp\u003eThe trial tested 160 mg of aspirin once daily for three years, starting within 12 weeks after surgery. This is a low dose, lower than standard pain-relief doses but higher than the 81 mg baby aspirin used for heart protection. Always follow your doctor's prescription rather than choosing a dose yourself.\u003c\/p\u003e\n\u003ch3\u003eIs taking aspirin now a standard recommendation after colorectal cancer surgery?\u003c\/h3\u003e\n\u003cp\u003eNot yet. The ALASCCA trial is one randomized study with strong results, but confirmatory trials are needed before aspirin becomes a routine recommendation. Discuss the findings with your oncology team and ask whether any newer studies have been published. Aspirin would be an addition to, not a replacement for, standard treatments.\u003c\/p\u003e\n\u003c!-- ddn:faq:end --\u003e\n\n\u003ch2 id=\"source\"\u003eSource Information\u003c\/h2\u003e\n\n\u003cp\u003e\u003cstrong\u003eOriginal article title:\u003c\/strong\u003e Low-Dose Aspirin for PI3K-Altered Localized Colorectal Cancer\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eAuthors:\u003c\/strong\u003e A. Martling, I. Hed Myrberg, M. Nilbert, H. Grönberg, F. Granath, M. Eklund, T. Öresland, L.H. Iversen, C. Haapamäki, M. Janson, K. Westberg, J. Segelman, U. Ersson, M. Prytz, E. Angenete, R. Bergström, M. Mayrhofer, B. Glimelius, and J. Lindberg, for the ALASCCA Study Group\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eJournal:\u003c\/strong\u003e \u003cem\u003eThe New England Journal of Medicine\u003c\/em\u003e, September 18, 2025, Vol. 393, No. 11, pages 1051–1064. DOI: 10.1056\/NEJMoa2504650. Copyright © 2025 Massachusetts Medical Society.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eTrial registration:\u003c\/strong\u003e ClinicalTrials.gov number, NCT02647099; EudraCT number, 2015-004240-19. Funded by the Swedish Research Council and others. Pfizer provided the aspirin free of charge but had no role in trial design or conduct.\u003c\/p\u003e\n\n\u003cp\u003e\u003cem\u003eThis patient-friendly article is based on peer-reviewed research. It is intended for educational purposes and should not replace individualized medical advice from your healthcare provider. Always consult your doctor before starting, stopping, or changing any medication, including aspirin.\u003c\/em\u003e\u003c\/p\u003e","brand":"DiagnosticDetectives.Com","offers":[{"title":"Default Title","offer_id":47427810590876,"sku":null,"price":0.0,"currency_code":"EUR","in_stock":true}],"url":"https:\/\/diagnosticdetectives.com.br\/products\/low-dose-aspirin-after-colorectal-cancer-surgery-new-hope-for-patients-with-pi3k-gene-changes","provider":"DiagnosticDetectives.Com","version":"1.0","type":"link"}