Kathryn Barry

Ph.D., M.P.H.

University of Maryland, Baltimore

Assistant Professor

PLCO (Learn more about this study)

PLCO-341

Feb 7, 2018

NSAID use and the risk of colorectal adenomas and colorectal cancer in the PLCO Cancer Screening Trial

Colorectal cancer is a cause of significant morbidity and mortality worldwide, and a reduction of its burden is of great public health interest (Ferlay et al., 2004). Non-steroidal anti-inflammatory drugs (NSAIDs), such as aspirin and ibuprofen, are a group of medications that are commonly used to treat pain, and there is growing evidence for a chemopreventive effect against colorectal tumorigenesis. NSAIDs have been associated with a reduced risk of colorectal adenoma formation (Baron et al., 2003; Sandler et al., 2003) and recurrence (Veettil et al., 2017; Zhao et al., 2016) in epidemiological studies. Notably, a recent meta-analysis reported that aspirin was as or more effective than flexible sigmoidoscopy or fecal occult blood tests in decreasing colorectal cancer incidence and mortality (Emilsson et al, 2016).

Despite their promise, there are many unanswered questions about the use of NSAIDs in this regard, and they have not yet been adopted for widespread chemoprophylaxis. There are knowledge gaps regarding the magnitude of association for NSAIDs with colorectal adenoma and colorectal cancer, and their role in colorectal tumorigenesis (i.e. the initiation vs. progression of colorectal tumors) remains unclear. Additionally, because the significant adverse effects of these drugs preclude indiscriminate use, there is a need to clearly delineate the appropriate patient sub-groups that will be most likely to benefit from chemoprophylaxis.

Using data from the Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial, we propose to prospectively evaluate the association between the use of NSAIDs and the risk of colorectal adenoma, adenoma recurrence, and colorectal cancer. Furthermore, we will evaluate this association within sub-groups of the study population, including age, sex and colorectal cancer family history, to identify the optimal patient characteristics for chemoprophylaxis with NSAIDs.

-Investigate the association between the self-reported use of NSAIDs and the risk of incident adenoma, recurrent adenoma and colorectal cancer in the PLCO cohort, overall and by tumor location

-Estimate the association between the use of NSAIDs and the risk of colorectal cancer in specific sub-populations, by stratifying on factors such as age, sex and family history of colorectal cancer