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.