Smoking cessation after diagnosis improves outcomes in kidney cancer

Patients who quit smoking after a diagnosis of kidney cancer were shown to have reduced risk of disease progression and mortality compared with those who continued smoking, according to findings published in the Journal of Clinical Oncology.^1,2

“This study adds to the evidence that it is never too late to quit smoking, even if you have already been diagnosed with cancer,” says David Zaridze, MD, DSc, PhD.

“This study adds to the evidence that it is never too late to quit smoking, even if you have already been diagnosed with cancer. These findings reinforce the importance of smoking cessation as a crucial component of care for patients with cancer that could improve their outcomes and overall health,” said senior author David Zaridze, MD, DSc, PhD, in a news release on the findings.²

The study enrolled 212 patients between 2007 to 2016 who were newly diagnosed with primary renal cell carcinoma (RCC) and were current smokers. Patients were followed annually through 2020 for a median of 8.2 years to assess smoking status and disease progression. Throughout the time of analysis, there were 110 cases of disease progression, 100 total deaths, and 77 cancer-specific deaths.

Among all participants, 84 (40%) quit smoking after diagnosis, with 56% of those quitting shortly after diagnosis and before the time of receiving first treatment. Of the remaining patients, 36% quit after treatment initiation during the first year of diagnosis, and 8% quit after the first year of diagnosis.

Data showed that at 5-year follow-up, overall survival among patients who had quit smoking was 85% compared with 61% for those that continued to smoke (P < .001). Progression-free survival was also higher for patients who quit smoking (80%) compared with those who continued to smoke (57%; P < .001).

Multivariable time-dependent regression models showed that smoking cessation was associated with an almost 50% reduction in the risk of all-cause mortality, a 55% reduction of risk for disease progression, and a 46% reduction in the risk of cancer-specific mortality.

These benefits remained consistent among all subgroups, including light smokers vs moderate to heavy smokers and those with early-stage vs late-stage tumors.

The study authors concluded, “This study provides strong evidence that quitting smoking after the diagnosis of kidney cancer can significantly improve the survival and reduce the risk of disease progression among these patients. Given that up to 20% of patients with kidney cancer are current smokers at diagnosis and most will continue to smoke afterward, it is critical to integrate smoking treatment into the routine management of these patients.”

References

1. Sheikh M, Mukeriya A, Zahed H, et al. Smoking cessation after diagnosis of kidney cancer is associated with reduced risk of mortality and cancer progression: A prospective cohort study. [published online ahead of print March 29, 2023]. J Clin Oncol. doi: 10.1200/JCO.22.02472.

2. Quitting smoking after being diagnosed with kidney cancer lowers the risk of cancer progression and mortality.News release. World Health Organization. March 29, 2023. Accessed April 4, 2023. https://www.iarc.who.int/news-events/quitting-smoking-after-being-diagnosed-with-kidney-cancer-lowers-the-risks-of-cancer-progression-and-mortality/