Radiotherapy for extensive stage small-cell lung cancer

Abstract

I read with interest the results of the trial of radiotherapy for extensive stage small-cell lung cancer (ES SCLC) by Ben Slotman and colleagues,1Slotman BJ van Tinteren H Praag JO et al.Use of thoracic radiotherapy for extensive stage small-cell lung cancer: a phase 3 randomised controlled trial.Lancet. 2015; 385: 36-42Summary Full Text Full Text PDF PubMed Scopus (330) Google Scholar and I would like to raise important issues that were not directly addressed by the authors.The authors note that the 2-year overall survival was improved in patients with ES SCLC who received thoracic radiotherapy in addition to prophylactic cranial irradiation. This finding is potentially practice-changing. However, a caveat exists regarding this statement, also not addressed in the accompanying Comment.2van Meerbeeck JP Ball D Small-cell lung cancer: local therapy for a systemic disease?.Lancet. 2015; 385: 9-10Summary Full Text Full Text PDF PubMed Scopus (8) Google Scholar The trial allowed treatments of disease progression at the discretion of the participating treatment centres, and these uncontrolled interventions (or absence thereof) could have affected apparent disease survival, even if they were internally consistent at each centre (details of which the authors did not report). I suggest a more cautious interpretation of the post-recurrence data as a clear 2-year survival benefit to the thoracic radiotherapy group. Notwithstanding, subgroups within that patient cohort might in the future have a stronger survival effect than is evident in the whole patient group.Details of the directly relevant patterns of intra-thoracic failure (ie, within, marginally within, or outside the radiotherapy field) would have been informative and will have implications for the design of future radiotherapy trials of management strategies for this disease.I declare no competing interests. I read with interest the results of the trial of radiotherapy for extensive stage small-cell lung cancer (ES SCLC) by Ben Slotman and colleagues,1Slotman BJ van Tinteren H Praag JO et al.Use of thoracic radiotherapy for extensive stage small-cell lung cancer: a phase 3 randomised controlled trial.Lancet. 2015; 385: 36-42Summary Full Text Full Text PDF PubMed Scopus (330) Google Scholar and I would like to raise important issues that were not directly addressed by the authors. The authors note that the 2-year overall survival was improved in patients with ES SCLC who received thoracic radiotherapy in addition to prophylactic cranial irradiation. This finding is potentially practice-changing. However, a caveat exists regarding this statement, also not addressed in the accompanying Comment.2van Meerbeeck JP Ball D Small-cell lung cancer: local therapy for a systemic disease?.Lancet. 2015; 385: 9-10Summary Full Text Full Text PDF PubMed Scopus (8) Google Scholar The trial allowed treatments of disease progression at the discretion of the participating treatment centres, and these uncontrolled interventions (or absence thereof) could have affected apparent disease survival, even if they were internally consistent at each centre (details of which the authors did not report). I suggest a more cautious interpretation of the post-recurrence data as a clear 2-year survival benefit to the thoracic radiotherapy group. Notwithstanding, subgroups within that patient cohort might in the future have a stronger survival effect than is evident in the whole patient group. Details of the directly relevant patterns of intra-thoracic failure (ie, within, marginally within, or outside the radiotherapy field) would have been informative and will have implications for the design of future radiotherapy trials of management strategies for this disease. I declare no competing interests. Use of thoracic radiotherapy for extensive stage small-cell lung cancer: a phase 3 randomised controlled trialThoracic radiotherapy in addition to prophylactic cranial irradiation should be considered for all patients with ES-SCLC who respond to chemotherapy. Full-Text PDF Open AccessRadiotherapy for extensive stage small-cell lung cancer – Authors' replyWhich patients with extensive stage small-cell lung cancer (ES SCLC) are most likely to benefit from thoracic radiotherapy after chemotherapy? Full-Text PDF