Current state of knowledge on immunotherapy in ECOG PS 2 patients. A systematic review.

Background: Patients with Eastern Cooperative Oncology Group Performance Status 2 (ECOG PS 2) are not included in most randomized clinical trials and registry studies. Nevertheless, immune checkpoint inhibitors are registered in the USA and Europe regardless of the performance status. Evidence regarding the effectiveness and safety of such treatment in this cohort is sparse.

Methods: Using PubMed (to July 2020), the relevant literature on the effect of ECOG PS 2 on the efficacy and safety of immunotherapy in patients with advanced non-small cell lung cancer (NSCLC) with ECOG PS 2 was searched.

Results: A database search conducted using an international repository (PubMed) identified 191 records. Additional 3 records were identified through other sources. After pre-selection, 92 records were excluded, and 102 full-text articles were assessed for eligibility. With further exclusion of articles not meeting the inclusion criteria, 44 studies were entered into the qualitative synthesis.

Conclusions: Immunotherapy seems to be justified in PS 2 patients with NSCLC. This method of treatment has been proven to be safe and tolerable. However, outcomes in this population remain suboptimal and the impact of immunotherapy in this cohort is less dramatic. Multiple scales evaluating many factors beyond PS scores have been suggested to help stratify the PS 2 to reinforce the chance of achieving better treatment outcomes. Randomized trials are needed to determine the benefits of immune checkpoint inhibitors (ICIs) for patients with poor ECOG PS.