Sub-lobar resections for peripheral non-small cell lung cancer measuring ≤ 2 cm: Insights from recent clinical trials

The findings of two well conducted trials that randomised 1803 patients with a peripheral non-small cell lung cancer measuring ≤ 2 cm to a lobar to sub-lobar resection have established the latter as a new standard of care. It is important for non-surgical oncologists to appreciate the details of study design and outcomes of both studies, given the possible impact they have for considerations of stereotactic ablative radiotherapy (SABR) for operable patients with early-stage NSCLC. Differences in overall survival between the study populations highlight the impact of confounding factors like smoking history and comorbidities on reported outcomes. For example, despite low post-operative mortality rates in both trials, the 5-year disease-free survival rate in the CALGB 140503 trial was only approximately 60 % with either surgical procedure. Both phase III trials required guideline recommended nodal staging, which does not reflect real world surgical practice, and which may limit the generalisability of the reported findings to local institutional outcomes. Furthermore, the emergence of other malignancies was recorded in 15-18 % of study patients during follow-up, and patients who underwent sub-lobar resections had a better long-term survival associated with a higher likelihood of undergoing additional curative treatments. These findings from the JCOG0802 and the CALGB 140503 will encourage more interest in enrolling patients into ongoing trials comparing surgical resection with SABR.