Meat Consumption, Nonsteroidal Anti-Inflammatory Drug Use, and Mortality among Colorectal Cancer Patients in the California Teachers Study

Jason A. Zell,Argyrios Ziogas,Joan A. Largent,Christina A. Clarke,Daniel O. Stram,Leslie Bernstein,Giske Ursin,Susan L. Neuhausen,Hoda Anton-Culver,Dennis Deapen

doi:10.1158/1940-6207.capr-09-0262

Abstract

A low-meat diet and regular use of nonsteroidal anti-inflammatory drugs (NSAID) have been associated with decreased mortality among colorectal cancer (CRC) patients. Here, we investigated the association between prediagnosis usual meat consumption and CRC-specific mortality, and whether meat consumption modifies the previously noted association between NSAID use and CRC-specific mortality among women in the California Teachers Study cohort. Women joining the California Teachers Study in 1995-1996 without prior CRC diagnosis, diagnosed with incident CRC during follow-up through December 2007, were eligible for inclusion. Meat intake (frequency and serving size) and NSAID use (aspirin or ibuprofen use) were ascertained via self-administered questionnaires before diagnosis. Vital status and cause of death were determined by linkage with mortality files. Multivariable Cox proportional hazards regression models were used to estimate hazard ratios for death and 95% confidence intervals. Prediagnosis meat consumption was not associated with CRC-specific mortality among 704 CRC patients (and 201 CRC-specific deaths), comparing patients in the lowest consumption tertile (0-5.4 medium-sized servings/wk) to those in the higher consumption tertiles. Regular NSAID use (1-3 times/wk, 4-6 times/wk, daily) versus none was associated with decreased CRC-specific mortality among patients in the lowest meat consumption tertile (hazard ratio, 0.22; 95% CI, 0.06-0.82), but not among patients in the higher meat intake tertiles. The previously observed mortality risk reduction among female CRC patients associated with regular NSAID use was restricted to patients who reported low meat intake before diagnosis. These findings have implications for CRC survivorship and tertiary CRC prevention.

Highlights

Colorectal cancer (CRC) is a substantial public health burden in the United States, with an estimated 146,970 incident cases and 49,920 deaths expected in 2009 [1]
Among female CRC patients, the previously observed reduction in CRC-specific mortality associated with pre-diagnosis regular non-steroidal anti-inflammatory drugs (NSAIDs) use [12] was observed only for patients reporting the lowest level of pre-diagnosis meat consumption (i.e.,
Consumption of meat from all sources was utilized for this analysis in accordance with prior data demonstrating survival effects related to dietary patterns in colorectal cancer patients [14,15]

Summary

Introduction

Colorectal cancer (CRC) is a substantial public health burden in the United States, with an estimated 146,970 incident cases and 49,920 deaths expected in 2009 [1]. A sizeable CRC survivorship cohort has developed, drawing attention to the importance of elucidating prognostic factors for survival and developing mortality risk reduction strategies after CRC diagnosis. Despite a long history of experimental research, [2,3,4] epidemiologic studies, [5,6,7] and clinical trials [8,9] examining the inhibitory effects of NSAIDs on CRC development, relatively few studies have examined how pre- or post-diagnosis NSAID use affects survival among CRC patients [10,11]. Pre-diagnosis NSAID use (when used regularly, or for a prolonged duration) was associated with decreased CRC-specific mortality in female CRC patients from the California Teachers Study (CTS) cohort [12] and post-diagnosis aspirin use was associated with a similar decreased mortality among stage I-III colon cancer patients [13]

Methods

Results

Conclusion