Impact of prior extrapulmonary cancer on survival after lung cancer: a systematic review and meta-analysis

This review aimed to examine the impact of previous extrapulmonary malignancies on the overall survival (OS) of lung cancer patients.

The online databases of PubMed, Embase, Scopus, and Web of Science were explored for studies published up to 22nd December 2022 and comparing outcomes of first lung cancer vs. second primary lung cancer with a history of previous extrapulmonary malignancy. Studies were to report adjusted data on OS. Meta-analysis was performed in a random-effects model.

Nine retrospective studies were eligible. A total of 267,892 lung cancer patients with prior extrapulmonary malignancy and 1,351,245 primary lung cancer patients were analyzed in the studies. Meta-analysis of all studies showed that prior extrapulmonary malignancy results in poor OS in lung cancer patients as compared to those with no history of such cancer (HR: 1.27 95% CI: 1.07, 1.50 I2=83%). The results did not change on sensitivity analysis. No publication bias was noted.

The result of this meta-analysis indicates that a history of prior extrapulmonary malignancy results in poor OS in patients with lung cancer. Caution is needed in the interpretation of the results owing to high interstudy heterogeneity. Further research is needed to assess how factors like the type of extrapulmonary malignancy, time interval of diagnosis, cancer stage, and treatment modality impact this relationship.