Examining the Accuracy of Self-Reported Smoking-Related Exposure among Recently Diagnosed Nonmuscle Invasive Bladder Cancer Patients.

PURPOSE

Cigarette smoking is a risk factor for developing nonmuscle invasive bladder cancer, and continued smoking exposure after diagnosis may increase the likelihood of adverse clinical outcomes. We compare self-reported vs biochemically verified nicotine exposure to determine the accuracy of self-report among recently diagnosed nonmuscle invasive bladder cancer patients.

MATERIALS AND METHODS

This cross-sectional analysis consisted of 517 nonmuscle invasive bladder cancer patients who contributed a urine or saliva specimen the same day as self-reporting their smoking, use of e-cigarettes, nicotine replacement therapy and whether they lived with a smoker. Cotinine, the primary metabolite of nicotine, was used as an objective biomarker of recent nicotine exposure.

RESULTS

The prevalence of high, low and no cotinine exposure was 13%, 54% and 33%, respectively. Overall, 7.3% of patients (38/517) reported being a current cigarette smoker, while 13% (65/517) had cotinine levels consistent with active smoking exposure. Of these 65 patients 27 denied current smoking, resulting in a sensitivity of self-reported current smoking of 58%. After considering other sources of nicotine exposure such as e-cigarettes, cigars, nicotine replacement therapy and living with a smoker, the sensitivity was higher, at 82%. Nearly all patients with low cotinine denied any smoking-related exposure.

CONCLUSIONS

Our findings suggest either biochemical verification with cotinine or additional questions about other sources of nicotine are needed to accurately identify nonmuscle invasive bladder cancer patients who have smoking-related exposures. Accurate classification of active and passive smoking exposure is essential to allow clinicians to advise cessation and help researchers estimate the association between post-diagnosis smoking-related exposure and nonmuscle invasive bladder cancer recurrence risk.