Background: Chemoradiotherapy is the standard treatment for locally advanced non-small cell lung cancer. Unlike metastatic disease, histological differences are usually not considered while planning chemoradiotherapy. This study aimed to compare clinical outcomes and relapse patterns between squamous cell carcinomas and adenocarcinomas, and investigated possible histology-specific approaches for chemoradiotherapy in locally advanced non-small cell lung cancer.
Methods: We retrospectively analyzed the outcomes and relapse patterns in patients who received definitive chemoradiotherapy for locally advanced non-small cell lung cancer in Katsura hospital between 2003 and 2012.
Results: A total of 68 and 33 patients with squamous cell carcinomas and adenocarcinomas, respectively, were enrolled. Patients with adenocarcinoma had less advanced T stages, and a larger proportion of female patients. Other factors were not different between the two groups. The median follow-up duration in all patients and survivors was 21.3 months and 91.4 months, respectively. Median survival and relapse-free survival were not significantly different between the two groups. In contrast, the failure patterns and incidences of distant failure were significantly different. Patients with squamous cell carcinomas had predominantly locoregional disease features and a shorter duration from relapse to death compared to patients with adenocarcinoma.
Conclusion: Failure pattern was significantly different between the two histologies. Among relapsed patients, the prognosis was poorer in those with squamous cell carcinomas than those with adenocarcinomas. Further studies, to evaluate histology-specific approaches in chemoradiotherapy, are warranted.
Keywords: Chemoradiotherapy; Histological difference; Non-small cell lung cancer; Prognosis after recurrence; Recurrence pattern.