Prognostic significance of intraoperative macroscopic serosal invasion finding when it shows a discrepancy in pathologic result gastric cancer

PURPOSE Depth of wall invasion is an important prognostic factor in patients with gastric cancer, whereas the prognostic significance of intraoperative macroscopic serosal invasion (mSE) findings remain unclear when they show a discrepancy in pathologic findings. This study, therefore, assessed the prognostic significance of mSE. METHODS Data from cohort of 2,835 patients with resectable gastric cancer who underwent surgery between 1990 and 2010 were retrospectively reviewed. RESULTS The overall accuracy of mSE and pathologic results was 83.4%. The accuracy of mSE was 75.5% in pT2. On the other hand, the accuracy of pT3 dropped to 24.5%. According to mSE findings (+/-), the 5-year disease-specific survival (DSS) rate differed significantly in patients with pT2 (+; 74.2% vs. -; 92.0%), pT3 (+; 76.7% vs. -; 91.8%) and pT4a (+; 51.3% vs. -; 72.8%) (P < 0.001 each), but not in patients with T1 tumor. Multivariate analysis showed that mSE findings (hazard ratio [HR], 2.275; 95% confidence interval [CI], 1.148-4.509), tumor depth (HR, 6.894; 95% CI, 2.325-20.437), nodal status (HR, 5.206; 95% CI, 2.298-11.791), distant metastasis (HR, 2.881; 95% CI, 1.388-6.209), radical resection (HR, 2.002; 95% CI, 1.017-3.940), and lymphatic invasion (HR, 2.713; 95% CI, 1.424-5.167) were independent predictors of 5-year DSS rate. CONCLUSION We observed considerable discrepancies between macroscopic and pathologic diagnosis of serosal invasion. However, macroscopic diagnosis of serosal invasion was independently prognostic of 5-year DSS. It suggests that because the pathologic results could not be perfect and the local inflammatory change with mSE(+) could affect survival, a combination of mSE(+/-) and pathologic depth may be predictive of prognosis in patients with gastric cancer.