Background: Patients with lung cancer and interstitial lung disease treated with radiotherapy are at risk of developing radiation pneumonitis. However, the association between interstitial lung abnormalities (ILAs) and radiation pneumonitis in patients with limited-stage small-cell lung cancer (LS-SCLC) remains unclear. Furthermore, the prognosis is uncertain for patients with SCLC and ILAs treated with chemoradiotherapy. We investigated the impact of ILAs on radiation pneumonitis and assessed the prognosis of patients with LS-SCLC and ILAs treated with chemoradiotherapy.
Methods: We retrospectively reviewed the medical records of 149 patients with LS-SCLC who received first-line treatment between January 2009 and December 2016.
Results: In the univariate analysis, the patients with ILAs showed a higher incidence rate of radiation pneumonitis compared with those without ILAs (64% vs. 10%, P < 0.001). Multivariate analysis confirmed that ILAs were significantly associated with the incidence of radiation pneumonitis. In the univariate analysis, patients with ILAs showed poorer overall survival than those without ILAs (median, 18.9 vs. 67.9 months, P = 0.0338). Multivariate analysis showed that ILAs were a significant independent negative prognostic factor. However, the 2-year and 5-year survival rates for the patients with ILAs treated with chemoradiotherapy were 36% and 26%, respectively, and 8% and 0%, respectively, for those treated with chemotherapy alone.
Conclusions: ILAs were found to be a predictive factor for radiation pneumonitis in patients with LS-SCLC treated with chemoradiotherapy. Patients with LS-SCLC and ILAs who were treated with chemoradiotherapy had both the possibility of long-term survival and risk of radiation pneumonitis.
Keywords: Chemoradiotherapy; Interstitial lung abnormalities; Interstitial lung disease; Limited-stage small-cell lung cancer; Radiation pneumonitis.