Adeyinka Laiyemo

MD, MPH

Howard University

Assistant Professor

PLCO (Learn more about this study)

PLCO-88

May 27, 2014

Effect of screening on colorectal cancer incidence and mortality associated with smoking, obesity and family history of colorectal cancer

The incidence of obesity continues to increase and obesity has been reported to increase the risk of CRC. Smoking is a putative risk factor for an increased risk of CRC. However, it remains controversial whether CRC screening guidelines should be targeted to these populations (obesity and smoking). Furthermore, a family history of non-syndromic or sporadic CRC has been associated with an increased risk of sporadic CRC. A family history of CRC is arguably the most improtant determinant of when CRC screening begins. However, it is uncertain the degree to which screening actually reduces the risk of development and mortality from CRC associated with a family hiostory of CRC.

We hypothesize that CRC screening can reduce CRC incidence and mortality associated with obesity, smoking and family history of CRC,.

In this proposal, we plan to evaluate whether flexible sigmoidoscopy screening would modify the effect of obesity, smoking and family history of CRC on the incidence and mortality from CRC using patient level data.

This project has the potential to inform and guide CRC screening guidelines and practice nationally and internationally.

1. To characterize CRC incidence and mortality by body mass index (BMI). We plan to categorize BMI into normal (< 25 kg/m2), overweight (25 – 29 kg/m2) and obese (≥ 30 kg/m2). We will compare overweight and obese participants to those with normal BMI. We will evaluate the effect of sigmoidoscopy screening on CRC incidence, stage at cancer diagnosis, and CRC-specific mortality.

2. To determine whether CRC incidence and mortality is associated with smoking status (never, former, and current smokers) and pack-years of smoking. We will evaluate the effect of sigmoidoscopy screening on CRC incidence, stage at cancer diagnosis, and CRC-specific mortality.

3. To evaluate CRC incidence and mortality by family history of CRC (Yes versus No) and assess effect modification with sigmoidoscopy screening. We will assess differences in incidence of CRC, stage at cancer diagnosis, and CRC-specific mortality.