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.
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
Gwen
G
Murphy
Xiao-Ou
XO
Shu
Yu-Tang
YT
Gao
Bu-Tian
BT
Ji
Michael Blaise
MB
Cook
Gong
G
Yang
Hong Lan
HL
Li
Nathaniel
N
Rothman
Wei
W
Zheng
Wong-Ho
WH
Chow
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