Survival and late toxicities following concurrent chemo-radiotherapy for locally advanced stage III non-small cell lung cancer: findings of a 10-year Australian single centre experience with long term clinical follow up

Background: The preferred management of patients with unresectable locally advanced non-small cell lung cancer (LA-NSCLC) is concurrent chemo-radiotherapy (CRT). Acute CRT-related toxicities are well defined, however, less is known about late toxicities. The aim of the study was to examine the outcomes and late toxicities in Stage III NSCLC treated with CRT. Methods: A retrospective review of the data from patients with stage III NSCLC treated with CRT was performed between May 2000 and June 2010. Demographics, tumour and treatment characteristics, toxicities and survival data were examined from hospital records of the patients. Progression free survival (PFS) and overall survival (OS) were evaluated by standard Kaplan-Meier survival curves. The censor date was set on 31 October 2016. Results: Sixty-three patients were identified with a median age of 66.6 years [interquartile range (IQR) 57.2-72.1], two-third (n=41, 65.1%) were male, majority were current or ex-smokers (n=52, 82.5%), 42 (66.7%) patients had stage IIIB disease and 21 (33.3%) had stage IIIA disease. The most common histologic subtype was adenocarcinoma 30 (47.6%). The median PFS and OS of the whole population was 10.6 months (95% CI, 4.1-17.3 months) and 21 months (95% CI, 12.7-29.3 months) respectively. The 5-year OS rates for stage IIIA and IIIB were 24% and 16% respectively. The 1-, 3- and 5-year OS rates for all patients were 63.5%, 46% and 18.7% respectively. Acute grade 3 and 4 toxicities included 28 haematological and 17 non-haematological events. The incidence of late toxicities was 58.9%. Thirty-three events of late grade 3 and 4 toxicities were recorded. The most common late toxicity was symptomatic radiation-induced pulmonary fibrosis (39.3%), others include ototoxicity (7.1%), persistent dysphagia (7.1%) and one case of acute myeloid leukaemia. All patients that were alive at the censor date had developed radiation-induced fibrosis with associated symptoms of respiratory insufficiency. Conclusions: The 5-year OS of patients with stage III NSCLC treated with CRT was in keeping with survival figures reported from prospective clinical trials. There is, however, significant morbidity associated with long-term survival and this should be taken into account when making informed treatment decisions.