Partner of Sld five (Psf) 3 is a member of the evolutionarily conserved heterotetrameric complex GINS (Go-Ichi-Ni-San). We previously reported that Psf3 could serve as a biomarker of poor prognosis in lung adenocarcinoma. Here, we used tissue microarrays to analyse Psf3 expression in lung adenocarcinoma and investigated whether its expression is associated with survival outcomes.METHODS
The study included 864 consecutive patients with lung adenocarcinoma who underwent complete resection at Hyogo Cancer Center between January 2002 and December 2009. Tissue microarrays were prepared, and Psf3 was detected using mouse antihuman Psf3 primary monoclonal antibodies. The status of Psf3 expression was determined using these microarrays.RESULTS
Of the 864 patients, 375 had high-positive Psf3 expression and 489 had low-positive expression. Psf3 expression was significantly associated with age, sex, T factor, lymph node metastasis, stage and P factor. The 5-year disease-free survival (DFS) rate was significantly lower in patients with high-positive Psf3 expression than in those with low-positive expression, and Psf3 expression, sex, age, T factor and lymph node metastasis were identified as independent and significant prognostic determinants. Among patients with Stage I adenocarcinoma, the 5-year DFS rate was significantly lower in those with high-positive Psf3 expression than in those with low-positive expression, and Psf3 expression was the most powerful survival predictor.CONCLUSIONS
The present findings strengthened our previous data demonstrating that high Psf3 expression in primary lung adenocarcinoma plays an important role in disease progression and is a prognostic indicator, particularly in early-stage adenocarcinoma.