medwireNews: Patients with muscle-invasive bladder cancer who are current or former smokers are more likely to respond poorly to cisplatin-based neoadjuvant chemotherapy than their nonsmoking counterparts, researchers report in BJU International.
Given that response to neoadjuvant chemotherapy is “an important prognostic factor for survival outcomes,” R Jeffrey Karnes (Mayo Clinic, Rochester, Minnesota, USA) and colleagues believe that “the identification of clinical factors that may affect [neoadjuvant chemotherapy] response is of major clinical importance.”
They therefore identified 201 patients who received neoadjuvant treatment before undergoing radical cystectomy for clinical stage T2–T4 disease that had not metastasized to the lymph nodes or systemically during 1999–2015. Of these, 28.9% were never smokers, 43.3% were former smokers, and 27.9% were current smokers.
The rate of no response (pathologic stage T2–T4 or node-positive disease) to neoadjuvant chemotherapy was significantly higher among current and former smokers than never smokers, at 73.2% and 56.3% versus 39.7%, respectively, while the complete response (pathologic stage T0 and node-negative disease) rate was correspondingly lower, at 17.9% and 26.4% versus 43.1%.
And in a multivariable model adjusting for parameters such as age, Charlson Comorbidity Index, and clinical stage, being a current or former smoker was significantly associated with no response, with corresponding odds ratios of 4.63 and 2.32.
Current smokers also had significantly worse recurrence-free survival than former and never smokers, with a 3-year rate of 50.3% versus 59.2% and 67.9%, respectively, and the association held true in multivariable analysis, which gave a hazard ratio for recurrence of 2.14 for current versus never smoking status.
The overall and cancer-specific survival rates were also significantly lower among current than former or never smokers, but smoking status was not found to be a significant predictor of either outcome in multivariable analysis.
Although the study authors acknowledge the need for large, prospective studies to evaluate the effect of smoking and smoking cessation on survival outcomes in this patient population, they say that “these results suggest that physicians should have a proactive role in educating patients regarding the detrimental effect of smoking on cancer-specific and overall health outcomes.”
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