Nonsteroidal Anti-inflammatory Drugs and Subsite-Specific Colorectal Cancer Incidence in the Iowa Women's Health Study

Abstract

Background: Previous epidemiologic studies have shown that regular use of nonsteroidal anti-inflammatory drugs (NSAIDs) is associated with decreased colorectal cancer risk. However, few studies have examined associations between NSAID use and subsite-specific colorectal cancer risks. Because tumors of the proximal and distal colon differ with respect to their genetic alterations, clinicopathologic features, and demographic distribution, further investigation of subsite-specific colorectal cancer risks may be rewarding. Methods: Data about aspirin and nonaspirin-NSAID use were recorded by self-report in 1992 among the initially cancer-free cohort of postmenopausal women in the Iowa Women's Health Study (n = 27,160). In total, 637 women developed colorectal cancer during the 11 years of follow-up, including 365 proximal colon, 132 distal colon, and 120 rectal cancer cases (11 overlapping and 9 not specified).

Aspirin Dose and Duration of Use and Risk of Colorectal Cancer in Men

“…Further studies should examine the potential for a differential effect of aspirin based on anatomic location which may be related to differences in the molecular characteristics of tumors. 41 Although previous studies have demonstrated an inverse relationship between aspirin and colorectal cancer, 7,8,14,29,[35][36][37][38][39][40][42][43][44][45][46][47][48][49][50][51][52][53][54] the present study differs in several important ways. First, because we collected detailed, updated information on aspirin at a range of doses over 18 years of follow-up, we were able to evaluate long-term use across a broad range of intake.…”

Regional differences in colorectal cancer incidence, stage, and subsite among American Indians and Alaska Natives, 1999-2004

“…Factors other than gender that are believed to influence subsite distribution include smoking, physical activity, alcohol abuse, diabetes, nonsteroidal anti-inflammatory drug use, and dietary factors. 40,[54][55][56][57][58][59][60][61][62][63] A better understanding of the relative risks of these variables and CRC in AI/AN populations is needed.…”

Aspirin, cyclooxygenase inhibition and colorectal cancer

“…Some suggested that 300-325 mg may be necessary for CRC prevention but most provided incomplete information regarding the dose and duration of aspirin treatment [7,8,10,11,27] . Therefore, taking the clinical trial and observational information together, there is very strong evidence that long-term LDA (75-325 mg/d) reduces the risk of CRC.…”