Family History of Bladder Cancer, Smoking Significantly Increase Risk of Disease

Researchers found a link between smoking and increased risk of bladder cancer in people with a positive family history of the condition. These study findings were reported in the World Journal of Clinical Oncology.

The study utilized the National Health Insurance database that is managed by the mandatory health insurance program operated by the government of South Korea. The researchers analyzed the database to identify patients’ biological parents, lifestyle risk factors, and confirmed cases of bladder cancer. They then calculated and evaluated levels of familial risk of bladder cancer for patients in this cohort. Patients were considered to have an affected parent if the parent had a diagnosis of bladder cancer. 

Using the database, 5,524,403 persons with a biological mother and father were identified, representing a total of 1.7 million families. Of these, 24,651 patients developed bladder cancer during the study period of 2002 through 2019. 

People with an affected parent showed a higher risk of bladder cancer, in comparison with people who had unaffected parents in an analysis adjusted for age and sex (hazard ratio [HR], 2.09; 95% CI, 1.41-3.08). Familial risk through an affected father was associated with an HR of 2.26 (95% CI, 1.51-3.39), the risk through an affected mother was associated with an HR of 1.10 (95% CI, 0.27-4.41). 

Incidence of bladder cancer was 0.43 (95% CI, 0.29-0.63) per 10,000 person-years in patients with an affected father, and 0.51 (95% CI, 0.19-1.35) per 10,000 person-years with an affected mother, or 0.44 (95% CI, 0.30-0.63) per 10,000 person-years with an affected parent overall. Incidence of bladder cancer in those without affected parents was 0.13 (95% CI, 0.13-0.14).

In an analysis adjusted for lifestyle factors, the HR for bladder cancer risk decreased only slightly (2.04; 95% CI, 1.38-3.01), implicating genetic predisposition as the primary factor in familial risk in this study. However, risk of bladder cancer for smokers with a positive family history was higher (HR, 3.60; 95% CI, 2.27-5.71), and the interaction between familial risk and smoking was statistically significant. 

Alcohol consumers with a positive family history of bladder cancer also appeared to have a higher risk of the disease. However, the interaction between familial risk and alcohol consumption was not statistically significant. 

“This nationwide population-based study demonstrated a 2.09-fold increased familial risk of bladder cancer and suggested that substantial interactions exist between family history of bladder cancer and smoking,” the researchers concluded. 

Reference

Kim HJ, Kim KH, Lee SW, et al. Familial risk and interaction with smoking and alcohol consumption in bladder cancer: a population-based cohort study. World J Oncol. 2023;14(5):382-391. doi:10.14740/wjon1639