Smoking status is rarely reported in genitourinary cancer trials

Few studies on trials involving genitourinary cancers include data on participants’ smoking status, according to findings from a systematic review presented during the 2021 American Urological Association Annual Meeting.¹

“This study highlights a deficiency in urologic oncology [randomized, controlled trials’] to assess smoking status and participants. Given smoking’s effects on treatments, survival, and quality of life, we believe this is an important area that deserves more attention,” said Calvin C. Zhao, MD, New York University School of Medicine, during a virtual presentation at the meeting.

The primary outcome of this review was whether a study collected and reported data on their participants’ smoking status. Secondary outcomes included details on how smoking status was reported, if trial arms were balanced, and if smoking status was included in the analysis.

Using PRISMA guidelines, investigators identified 622 articles and 354 later met criteria to be used in the review. Only 8.2% (n = 30) of studies reported on smoking. Of those, 27 studies reported smoking in the manuscript or supplement. And 96.3% of studies reported at baseline qualitatively, such as “never,” “former,” or “current”, instead of quantifying pack-years or intensity.

Only 3 studies reported final or subgroup analyses that included smoking. And of that, 2 reported significant differences in outcomes that were associated with smoking status.

No study reported a smoking measurement instrument, non-cigarette tobacco use, and changes in smoking status over time.

Studies had to be published between May 2010 and May 2020; were randomized phase 2 through 4 trials; reported in the top 10 medicine, urology, or oncology journals by 2018 Impact Factor; reported primary analysis on data; must be a therapeutic intervention; and patients had to have had prostate, urothelial, or kidney cancer.

Studies included were mostly trials in prostate cancer (n = 210), were published in the Journal of Clinical Oncology (n = 81), included patients from multiple continents (n = 119), reported on systematic therapies (n = 166), had an endpoint of overall survival (n = 102), and included patients with metastatic disease (n = 172).

Limitations of this study include the timeline allowing for the inclusion of older articles, a publication bias for more positive and later stage trials, and journal scope.

“However, we believe our search strategy adequately captured the most impactful and landmark trials in contemporary urologic oncology literature,” Zhao said. “Until we have a better understanding of the tobacco use patterns of our patients, we cannot fully characterize the effects of smoking on cancer outcomes.”

Future directions should be using validated and standardized instruments to measure smoking status such as the Cancer Patient Tobacco Use Questionnaire (C-TUQ). As well as, report smoking status through the entire study period, integrate the data into Electronic Medical Record and smoking cessation counseling. Zhao said integrating these practices will allow for a “more robust analysis” of interactions between tobacoo use and clinical trial outcomes

“Ultimately, we believe there is a great need for more rigorous attention to smoking in urologic cancer patients. The way forward, we believe, is for urologists to play a more active role in not just smoking assessment, but also smoking cessation,” Zhao concluded.

Reference

1. Matulewicz R, Zhao C, Myrie A, et al. A systematic review and scoping analysis of smoking cessation after a urologic cancer diagnosis. Presented at: 2021 American Urological Association Annual Meeting; September 10-13, 2021; virtual. Abstract LBA02-01