Comparison of recurrence patterns in patients receiving chemoradiotherapy following induction chemotherapy and patients receiving chemoradiotherapy initially in the treatment of stage III non-small cell lung cancers

Purpose: The standard treatment for inoperable Stage III non-small cell lung cancer is definitive concurrent chemoradiotherapy followed by maintenance therapy. When patients cannot receive standard therapy for a variety of reasons, concurrent chemoradiotherapy after induction chemotherapy is also an effective treatment option. To determine which treatment modality should be chosen in which situation, we compared the recurrence patterns of concurrent chemoradiotherapy and concurrent chemoradiotherapy after induction chemotherapy regimens. Methods: In this study, data of 166 patients who received curative treatment at the Department of Radiation Oncology at Dicle University Faculty of Medicine with a diagnosis of non-small cell lung cancer between January 1, 2014 and December 31, 2023 were retrospectively analyzed. The patients were divided into two groups: concurrent chemoradiotherapy (CRT) group and induction chemotherapy post-chemoradiotherapy (CT+CRT) group. Treatment responses and recurrence patterns of the groups were examined. Results: The median follow-up was 22.2 months. The CRT group consisted of 67 patients; the CT+CRT group consisted of 99 patients. No significant difference was found between the groups in terms of 1, 2, and 3-year overall survival and progression-free survival. Nausea and vomiting were more common in the CT+CRT group (p=0.01 and p=0.02). The partial response rate to treatment was higher in both groups; 77.6% for the CRT group and 71.7% for the CT+CRT group. There was no significant difference in recurrence patterns between the groups (p=0.707). Conclusion: When comparing the recurrence patterns between the groups, no statistically significant difference was found. In patients who cannot receive concurrent chemoradiotherapy, concurrent chemoradiotherapy after induction chemotherapy seems safe and feasible. The results need to be evaluated in prospective randomized studies with larger patient cohorts.