Association between systemic chemotherapy before chemoradiation and increased risk of treatment-related pneumonitis in esophageal cancer patients treated with definitive chemoradiotherapy

BACKGROUND: There is limited information on risk factors for treatment-related pneumonitis in esophageal cancer patients. AIM OF THE STUDY: To determine factors associated with treatment-related pneumonitis in esophageal cancer patients treated with definitive chemoradiotherapy. MATERIALS AND METHODS: We retrospectively reviewed clinical data from esophageal cancer patients treated with definitive chemoradiotherapy from 2000 to 2003. Demographic, clinical, and treatment-related data were collected for all patients. The time to occurrence of grade ≥2 pneumonitis was calculated from the end of radiotherapy. Univariate analyses were performed to determine the existence of any association between patient demographic, clinical, or treatment characteristics and pneumonitis. RESULTS: In total, 96 patients were included in the study with a median follow-up of 8 months (range, <1-48 months). Among them, 23 patients also received an average of two cycles of systemic chemotherapy before the initiation of concurrent chemoradiation. The incidence of grade ≥2 pneumonitis was 22% at 1 year. Systemic chemotherapy before concurrent chemoradiation was significantly associated with an increased risk of grade ≥2 pneumonitis (p = 0.003), with the 1-year incidence of grade ≥2 pneumonitis for patients with and without systemic chemotherapy being 49 and 14%, respectively. No other clinical or dosimetric factors investigated were associated with the risk of grade ≥2 pneumonitis. CONCLUSIONS: Systemic chemotherapy before concurrent chemoradiation was significantly associated with an increased risk of grade ≥2 pneumonitis, suggesting that induction chemotherapy may have sensitized the lung tissue to radiation damage in esophageal cancer patients.