Chemotherapy Induced Pathologic Complete Response in Malignant Pleural Mesothelioma A Review and Case Report

Introduction: Malignant pleural mesothelioma is a rare aggressive disease with a poor prognosis and usually modest responses to chemotherapy. Complete responses (CRs) to chemotherapy are rare. Evaluation is usually based on radiology, and CR is therefore clinical CR (cCR) and whether this indicates absence of viable tumor cells is unknown. We have observed two cases of CR which at subsequent surgery were histologically verified, thus being pathologic CRs (pCRs). pCR after chemotherapy is thus possible but rare, and we here present the cases from our institution together with a review on the literature available on the subject. Methods: A literature search using relevant keywords was performed in PubMed and MedLine. Results: A larger number of reports on cCR but only five reports on pCR were identified. All published cases of pCR, 16 patients in five trials, are presented and discussed, and larger trials reporting cCR are mentioned. pCR did not in all cases correspond to cCR. The cases having pCR identified all had the epithelial or unknown subtype, and all had early-stage disease before treatment. Conclusion: pCR is possible but rare, and a pCR does not always require a cCR. So far reported cases of pCR have all had the epithelial or unknown subtype and pretreatment stages have been low. The cases in our institution also had epithelial subtype but had stage III disease, and it thus seems possible to obtain a pCR despite a larger tumor burden.