Neoadjuvant immune checkpoint inhibitors in resectable non-small-cell lung cancer: a systematic review

Background: The neoadjuvant use of immune checkpoint inhibitors (ICIs) in resectable non-small-cell lung cancer (NSCLC) is currently an area of active ongoing research. The place of neoadjuvant ICIs in the treatment guidelines needs to be determined. We carried out a systematic review of published data on neoadjuvant ICIs in resectable NSCLC to study its efficacy and safety. Patients and methods: A literature search was carried out using the MEDLINE (PubMed) and Embase databases to retrieve articles and conference abstracts of clinical trials measuring the efficacy [major pathological response (MPR) and pathological complete response (pCR)] and safety (failure to undergo resection, surgical delay, treatment-related adverse events (trAEs) grade >= 3) of neoadjuvant immunotherapy in resectable NSCLC until July 2021. Results: Nineteen studies with a total of 1066 patients were included in this systematic review. Neoadjuvant immunotherapy was associated with improved pathological response rates, especially in combination with chemotherapy. Using mono ICI, dual therapy-ICI, chemoradiation-ICI, radiotherapy-ICI, and chemo-ICI, the MPR rates were 0%-45%, 50%, 73%, 53%, and 27%-86%, respectively. Regarding pCR, the rates were 7%-16%, 33%-38%, 27%, 27%, and 9%-63%, respectively. Safety endpoints using monotherapy-ICI, dual therapy-ICI, chemoradiation-ICI, radiotherapy-ICI, and chemo-ICI showed a failure to undergo resection in 0%-17%, 19%-33%, 8%, 13%, and 0%-46%, respectively. The trAEs grade >= 3 rates were 0%-20%, 10%-33%, 7%, 23%, and 0%-67%, respectively. Conclusion: In patients with resectable NSCLC stage, neoadjuvant immunotherapy can improve pathological response rates with acceptable toxicity. Further research is needed to identify patients who may benefit most from this approach, and adequately powered trials to establish clinically meaningful benefits are awaited.