Family cancer history affecting risk of colorectal cancer in a prospective cohort of Chinese women.
An elevated risk of colorectal cancer has been associated with sporadic colorectal cancer in first-degree relatives, mostly in Western populations. Limited data exist from traditionally low-risk areas, such as Asia, where the prevalence of risk factors may differ. We examined the association of family history of cancer and subsequent colorectal cancer risk in a cohort of traditionally low-risk Chinese women. We followed 73,358 women in the Shanghai Women's Health Study for cancer incidence until December 2005. After an average of 7 years of follow-up, 391 women were diagnosed with colorectal cancer. We calculated hazard ratios and 95% confidence intervals using Cox proportional hazards models adjusted for age, smoking, family income, education, body mass index, physical activity, and history of diabetes. We observed a significant association between colorectal cancer risk and history of a parent being diagnosed with colorectal cancer (hazard ratio: 3.34; 95% confidence interval: 1.58, 7.06). No association was observed for colorectal cancer diagnosed among siblings. Colorectal cancer risk was not influenced by a positive family history of cancer generally or any of the other cancers investigated (lung, breast, prostate, gastric, esophageal, endometrial, ovarian, urinary tract, central nervous system, and small bowel). Our cohort results suggest that consistent with findings from Western populations, having a family history of colorectal cancer may influence colorectal cancer risk to a similar extent in a low-risk population.
Murphy
Gwen
G
Cancer Prevention Fellowship Program, Office of Preventive Oncology, National Cancer Institute, National Institutes of Health, Department of Health and Human Services, Rockville, MD, USA. murphygw@mail.nih.gov
Shu
Xiao-Ou
XO
Gao
Yu-Tang
YT
Ji
Bu-Tian
BT
Cook
Michael Blaise
MB
Yang
Gong
G
Li
Hong Lan
HL
Rothman
Nathaniel
N
Zheng
Wei
W
Chow
Wong-Ho
WH
D000328:Adult; D000368:Aged; D044466:Asian People / Q000235:genetics / Q000706:statistics & numerical data; D002277:Carcinoma / Q000453:epidemiology / Q000209:etiology* / Q000235:genetics; D002681:China / Q000453:epidemiology; D015331:Cohort Studies; D015179:Colorectal Neoplasms / Q000453:epidemiology / Q000209:etiology* / Q000235:genetics; D005192:Family Health; D005260:Female; D020022:Genetic Predisposition to Disease; D006801:Humans; D008875:Middle Aged; D012307:Risk Factors; D012923:Social Class