Comparison of the outcome between immunotherapy alone or in combination with chemotherapy in EGFR-mutant non-small cell lung cancer.

Whether ICIs combined with chemotherapy can improve outcomes in EGFR-mutant non-small cell lung cancer (NSCLC) remains uncertain. Patients with EGFR-mutant NSCLC and who progressed on first-line EGFR-TKIs treatment were retrospectively collected. We reviewed the outcome of these patients treated with ICIs or ICIs combined chemotherapy (ICI + C). Total 30 patients were included. The ORR were 9.1% and 25.0% for the ICI and ICI + C groups. The ICI + C group showed the trend of longer progression-free survival and overall survival periods. Patients without the T790M mutation had a significantly longer PFS than did those without this mutation (4.23 [95% CI: 2.75-5.72] vs. 1.70 [95% CI: 0.00-3.51] months, HR:4.45, p = 0.019). ICIs combined with chemotherapy tended to be more effective than ICIs alone in pretreated EGFR-mutant NSCLC. The T790M mutation may be a potential biomarker.