Aspirin Use and Survival After Diagnosis of Colorectal Cancer

[Guest guest]

Asperin inhibits tumor growth after a new study in JAMA.

The Journal of the American Medical Association (JAMA)

Vol. 302 No. 6, August 12, 2009

Aspirin Use and Survival After Diagnosis of Colorectal Cancer

T. Chan, MD, MPH; Shuji Ogino, MD, PhD; S. Fuchs, MD, MPH

JAMA. 2009;302(6):649-658.

Context: Aspirin reduces risk of colorectal neoplasia in randomized trials and

inhibits tumor growth and metastases in animal models. However, the influence of

aspirin on survival after diagnosis of colorectal cancer is unknown.

Objective: To examine the association between aspirin use after colorectal

cancer diagnosis on colorectal cancer–specific and overall survival.

Design, Setting, and Participants: Prospective cohort study of 1279 men and

women diagnosed with stage I, II, or III colorectal cancer. Participants were

enrolled in 2 nationwide health professional cohorts in 1980 and 1986 prior to

diagnosis and followed up through June 1, 2008.

Main Outcome Measure: Colorectal cancer–specific and overall mortality.

Results: After a median follow-up of 11.8 years, there were 193 total deaths

(35%) and 81 colorectal cancer–specific deaths

(15%) among 549 participants who regularly used aspirin after colorectal cancer

diagnosis, compared with 287 total deaths

(39%) and 141 colorectal cancer–specific deaths (19%) among 730 participants who

did not use aspirin. Compared with nonusers, participants who regularly used

aspirin after diagnosis experienced a multivariate hazard ratio (HR) for

colorectal cancer–specific mortality of 0.71 (95% confidence interval [CI],

0.53-0.95) and for overall mortality of 0.79 (95% CI, 0.65-0.97). Among 719

participants who did not use aspirin before diagnosis, aspirin use initiated

after diagnosis was associated with a multivariate HR for colorectal

cancer–specific mortality of 0.53 (95% CI, 0.33-0.86). Among 459 participants

with colorectal cancers that were accessible for immunohistochemical assessment,

the effect of aspirin differed

significantly according to cyclooxygenase 2 (COX-2) expression (P for

interaction = .04). Regular aspirin use after diagnosis was associated with a

lower risk of colorectal cancer–specific mortality among participants in whom

primary tumors overexpressed COX-2 (multivariate HR, 0.39; 95% CI, 0.20-0.76),

whereas aspirin use was not associated with lower risk among those with primary

tumors with weak or absent expression (multivariate HR, 1.22; 95% CI,

0.36-4.18).

Conclusion: Regular aspirin use after the diagnosis of colorectal cancer is

associated with lower risk of colorectal cancer–specific and overall mortality,

especially among individuals with tumors that overexpress COX-2.

Author Affiliations: Gastrointestinal Unit, Massachusetts General Hospital and

Harvard Medical School (Dr Chan); Department

of Pathology, Brigham and Women's Hospital, Harvard Medical School, and

Department of Epidemiology, Harvard School of Public

Health (Dr Ogino); Department of Medical Oncology, Dana-Farber Cancer Institute

(Drs Ogino and Fuchs); Channing Laboratory,

Department of Medicine, Brigham and Women's Hospital, and Harvard Medical School

(Drs Chan and Fuchs) Boston, Massachusetts.