Psf3 as a possible biomarker of postoperative chemotherapy for patients with early pulmonary adenocarcinoma.

Background Partner of Sld five 3 (Psf3) is a member of the heterotetrameric complex that consists of SLD5, Psf1, Psf2, and Psf3. We have shown in previous studies that high Psf3 expression was a poor prognostic marker for pulmonary adenocarcinoma. Here, we statistically evaluated the relationship between clinicopathologic factors and Psf3 expression in stage I pulmonary adenocarcinoma. Methods A total of 583 patients who had undergone complete resection of stage I pulmonary adenocarcinoma from January 2002 to December 2009 were included in the study. Tissue microarrays were performed, and the resected tumors were divided into groups according to Psf3 expression. Results Of 583 patients, high expression of Psf3 was observed in 211 (36.2%) and low expression of Psf3 observed in 372 (63.8%) patients. Among stage I patients, the five-year survival rate was 76.7% in the Psf3 high expression group and 90.9% in the Psf3 low expression group (P < 0.0001). On multivariate analysis, Psf3 was found to be the independent prognostic factor. Among stage I patients in the Psf3 high expression group, a significantly greater five-year survival rate was observed in patients who received postoperative chemotherapy with tegafur-uracil than in those who underwent surgery alone (P < 0.0001). In contrast, among stage I patients in the Psf3 low expression group, no difference was found in the five-year survival, regardless of the presence or absence of tegafur-uracil (P = 0.873). Conclusion The Psf3 expression was an independent prognostic factor and could be a biomarker of adjuvant tegafur-uracil for stage I pulmonary adenocarcinoma. Key points Significant findings of the study: The Psf3 expression could be a biomarker of adjuvant tegafur-uracil administration for stage I pulmonary adenocarcinoma. What this study adds: Appropriate patients of adjuvant chemotherapy for stage I pulmonary adenocarcinoma using Psf3 expression could be selected.