Prospective Investigation of Body Mass Index, Colorectal Adenoma, and Colorectal Cancer in the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial

Abstract

A B S T R A C T PurposeObesity has consistently been linked to an increased risk of colorectal cancer, particularly among men. Whether body mass index (BMI) differentially influences the risk across the stages of colorectal cancer development remains unclear. We evaluated the associations of BMI with colorectal adenoma incidence, adenoma recurrence, and cancer in the context of a large screening trial, in which cases and controls had an equal chance for disease detection. MethodsWe prospectively evaluated the association between baseline BMI and the risk of incident distal adenoma (1,213 cases), recurrent adenoma (752 cases), and incident colorectal cancer (966 cases) among men and women, ages 55 to 74 years, randomly assigned to receive flexible sigmoidoscopy screening as part of the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial. We calculated odds ratios (ORs) and 95% CIs for adenoma incidence and recurrence, and hazard ratios (HRs) and 95% CIs for colorectal cancer incidence, using multivariable-adjusted models. ResultsCompared with normal-weight men (18.5 to 24.9 kg/m 2 ), obese men (Ն 30 kg/m 2 ) had significantly higher risk of incident adenoma (OR, 1.32; 95% CI, 1.06 to 1.65) and colorectal cancer (HR, 1.48; 95% CI, 1.16 to 1.89) and a borderline increased risk of recurrent adenoma (OR, 1.50; 95% CI, 0.98 to 2.30). No associations were observed for either adenoma or cancer in women. ConclusionData from this large prospective study suggest that obesity is important throughout the natural history of colorectal cancer, at least in men, and colorectal cancer prevention efforts should encourage the achievement and maintenance of a healthy body weight in addition to regular screenings.

The risk of colonic adenomas and colonic cancer in obesity

“…Similarly, Jacobs et al (60) reported an increased risk of adenoma recurrence over 3.1 years of follow-up among men (OR = 1.36; 95%CI: 1.01–1.83) without any association among women (OR = 0.90; 95%CI: 0.60–1.33). This was comparable to the report by Kitahara et al (61) using data from the Prostate, Lung, Colorectal and Ovarian (PLCO) screening Trial. The authors found a borderline increased risk of adenoma recurrence among men (OR, 1.50; 95% CI, 0.98 to 2.30) but not among women.…”

Validation of the Asia Pacific Colorectal Screening (APCS) score in a Western population: An alternative screening tool

“…This is supported by previous publications that lower rates of CRC are associated with caloric restriction 29 and that the risk of colonic adenomas increases with increasing BMI. 24 It is possible that the reason there has not been a clearer relationship between obesity or BMI and CRC and its precursor lesions is because the relationship is non-linear, particularly in the most obese patients in our cohort. We did not recruit any patients with a BMI in excess of 46 kg/m 2 .…”

“…Western populations differ to Asian populations in several ways. Among them is the high rate of obesity and the metabolic syndrome, which have been associated with an increase in the risk of colonic adenomas 23,24 and CRC. [25][26][27][28] Conversely, caloric restriction and a low BMI may protect against developing cancer.…”

Fetal Growth and Subsequent Maternal Risk of Colorectal Cancer

“…We were able to examine the specific components of birth weight—fetal growth and gestational age—while adjusting for potential confounders including maternal BMI and diabetes. Obese women deliver heavier babies on average (28, 29), and obesity is associated with a modestly increased risk of colorectal cancer (30), although this association has been more evident among men and is not consistently found among women (48, 49). Similarly, diabetic mothers also deliver heavier babies on average (29), and diabetes has been associated with a modestly increased risk of colorectal cancer (31).…”