Dose intensity and dose density of first line Platinum and Etoposide (PE) chemotherapy does not influence Overall Survival (OS) of Small Cell Lung Cancer (SCLC) patients. The effect of treatment length, however, remains unclear. Current guidelines recommend treating beyond four cycles – and up to six - in patients that respond to and tolerate systemic treatment. This has led to variable practice both in real-life and clinical research. Here we aimed to quantify the possible clinical benefit of the extended regimen in our real-life patients treated with PE doublet.
Of all patients with SCLC treated in our network with non-concurrent first line PE chemotherapy between 2008 and 2015, we retrospectively identified patients that received four cycles (4c) or more (>4c), and compared clinical outcomes between both groups.
We identified 671 patients overall; 578 (86%) received 4c and 93 (14%) received >4c. 74% of patients in the >4c group had stage IV disease. Of 310 patients with stage IV disease, 241 (78%) had 4c and 69 (22%) had >4c. Performance status, comorbidities and radiological responses were similarly distributed between the latter treatment groups. >4c patients were more likely to have sequential thoracic radiotherapy, which may indicate a lower metastatic burden in this group. Nevertheless, there were no statistically significant differences when comparing clinical outcomes. The median Duration of Response (time from last chemotherapy cycle to progression) was 5 months in both groups (HR 1.22; 95% CI 0.93-1.61). Median PFS (Progression-free Survival; time from diagnosis to progression) was 8 months (4c) versus 9 months (>4c) (HR 0.86; 0.66-1.13), and median OS (time from diagnosis to death) was 11 (4c) versus 12 (>4c) months (HR 0.86; 0.66-1.14).
Our results highlight a lack of clinical benefit by extending first line platinum combination treatment beyond four cycles in selected patients. This supports limiting the number of cycles to four until the superiority of a longer regimen is identified in a randomised study.
Clinical trial identification
Legal entity responsible for the study
Department of Clinical Governance, Clatterbridge Cancer Centre.
Has not received any funding.
All authors have declared no conflicts of interest.