Abstract
Background and objectives Head and neck cancers are aggressive tumours with a multidisciplinary treatment strategy. Concurrent chemoradiotherapy is recommended for locally advanced cases. The carboxyhaemoglobin level is higher in smokers, resulting in a hypoxic environment and radio resistance, which affect treatment outcomes. Data for effect of continued smoking is not available in the Indian setting. This study aims to compare treatment response, failure rate, patterns, and progression-free survival in current smokers vs. former smokers receiving definitive concurrent chemoradiotherapy for head and neck cancer. Methods We conducted this retrospective observational study in patients receiving definitive chemoradiotherapy for head and neck cancer with two groups: current smokers and former smokers. Both arms received weekly 40 mg/m2 cisplatin along with radiotherapy. Endpoints included treatment response, progression-free survival, and failure patterns. Results There were fewer complete treatment responses and more failures in current smokers receiving CRT, with a significant difference in progression-free survival. Interpretation & conclusions Continued smoking during definitive chemoradiotherapy for head and neck cancers resulted in poorer treatment outcomes. Integrating tobacco cessation in oncological care should be a standard of care in managing head and neck cancers.