Bladder cancer risk as modified by family history and smoking.
BACKGROUND
The familial risk of bladder cancer (BC) is not well understood and, to date, little attention has been paid to the joint effect of smoking and family history in modifying the risk of BC. The authors investigated the role of family history in association with the risk of BC.


METHODS
Case and control probands were identified as part of an on-going BC case-control study. The relative risk associated with a family history of BC was estimated.


RESULTS
In total, 713 cases and 658 controls were included. In a case-control analysis, compared with individuals who never smoked and who had no family history of BC, probands who had smoked and who also had a positive family history were at 5.31-fold increased risk of BC (P for interaction = .04). The 713 case probands and the 658 controls reported 5160 and 4816 first-degree relatives, respectively. Compared with never-smoking relatives who had probands diagnosed with BC at an older age (age >65 years), ever-smoking relatives who had probands diagnosed at a younger age (ages 40-65 years) showed a 6.89-fold (95% confidence interval, from 2.25-fold to 21.12-fold) increased risk. Similar results were obtained for the joint effects of family history of BC and smoking. CONCLUSIONS. The current results indicated that a positive family history of BC may have interacted with smoking habits to increase the risk of BC in the study population.
Lin
Jie
J
Department of Epidemiology, The University of Texas M. D. Anderson Cancer Center, Houston, Texas 77030, USA.
Spitz
Margaret R
MR
Dinney
Colin P
CP
Etzel
Carol J
CJ
Grossman
H Barton
HB
Wu
Xifeng
X
D000368:Aged; D016022:Case-Control Studies; D005192:Family Health; D005260:Female; D020022:Genetic Predisposition to Disease; D006801:Humans; D008297:Male; D008487:Medical History Taking; D008875:Middle Aged; D012307:Risk Factors; D012907:Smoking / Q000009:adverse effects* / Q000235:genetics; D001743:Urinary Bladder / Q000187:drug effects*; D001749:Urinary Bladder Neoplasms / Q000209:etiology*