Background: Amrubicin chemotherapy is a treatment option for patients with non-small cell lung cancer (NSCLC) after third-line treatment in Japan. Although topoisomerase-II (Topo-II), a target of amrubicin, has been reported to be a prognostic or predictive marker for chemosensitivity and clinical outcomes in various types of malignancies, its effects in the Japanese population remain unknown. Methods: Data regarding 44 patients with advanced NSCLC treated with amrubicin between April 2004 and May 2014 were retrospectively analyzed. We evaluated the expression levels of Topo-II by immunohistochemical staining of tumor specimens obtained via biopsy or surgical resection. Results: The majority of enrolled patients were men (68%) with a median age of 67 (range, 43-78) years. The most common histological type was adenocarcinoma (70%). High Topo-II expression was observed in 13 (30%) of the 44 patients. The median progression-free survival and overall survival (OS) durations were 1.8 and 8.8 months, respectively. While there was no significant association between Topo-II expression and progression-free survival, patients with low Topo-II expression had significantly longer OS than did those with high Topo-II expression. Good performance status and low expression of Topo-II were all significantly associated with a favorable OS. Conclusion: Low expression of Topo-II was identified as an independent prognostic factor for longer survival in patients with NSCLC receiving amrubicin, a Topo-II inhibitor.
Key pointsSignificant findings of the study:• The median progression-free survival and overall survival (OS) durations were 1.8 and 8.8 months, respectively. • While there was no significant association between Topo-II expression and progression-free survival, patients with low Topo-II expression had significantly longer OS than did those with high Topo-II expression. • Good performance status and low expression of Topo-II were all significantly associated with a favorable OS.