Clinical features affecting survival in metastatic NSCLC treated with immunotherapy: a critical review of published data

Immune checkpoint inhibitors (ICIs) represent one of the main steps forward for the treatment of advanced or metastatic non-small-cell lung cancer (NSCLC), without oncogenic driver alterations. Despite this recent progress, only a minority of patients achieve a broad and durable benefit and another proportion report poor survival and sometimes fast disease progression, confirming the need to optimise the patient's selection. To date, several issues are unsolved about how to personalise the immunotherapy treatment for individual patients. In this review, analysing data from pivotal randomised clinical trials (RCTs), we discuss patient baseline clinical and demographic features, including sex, age, ECOG performance status, smoking habit and specific site of metastases (liver, bone and brain) that may influence the efficacy outcomes in patients treated with ICIs. The high performance of the ICIs blurred the vision on different efficacy-limiting factors, which require extensive evaluation to improve the understanding of the tumour-specific immune response, in which clinical drivers could be useful for better patient stratification.