gms | German Medical Science

Background: Neoadjuvant treatment can influence T-category by potential downstaging. Due to possible biological tumor selection by neoadjuvant therapy, a direct comparison of pT- and ypT-category seems problematic. We thus evaluated, whether ypT- and pT-category differ with regard to prognosis.

Materials and methods: This study is a retrospective analysis of 745 patients with esophagogastric adenocarcinoma (163 AEG I, 190 AEG II, 52 AEG III, 340 stomach) without distant metastasis (M0), who underwent curative surgery (423 primary surgery, 322 after neoadjuvant chemotherapy, R0-resection: 640) at our institution from 01/2001 till 06/2015. Qualitative parameters were compared by χ2-test. Survival analyses were performed according to Kaplan-Meier (log-rank test).

Results: Pathological T-category (p<0.001) significantly differed between patients with primary surgery and those receiving neoadjuvant chemotherapy: pT1: 110 (26.0%), pT2: 76 (18.0%), pT3: 187 (44.2%), pT4: 49 (11.6%); ypT0: 31 (9.6%), ypT1: 29 (9.0%), ypT2: 44 (13.7%), ypT3: 182 (56.5%), ypT4: 36 (11.2%).

After primary surgery pT-category was prognostically relevant (mOS [median overall survival] pT1: n.r. [not reached], pT2: 84.2, pT3: 30.5, pT4: 19.1 months, p<0.001; R0-resected patients: mOS pT1: n.r., pT2: 103.8, pT3: 35.2, pT4: 19.1 months, p<0.001). In patients who underwent neoadjuvant chemotherapy ypT-category also was statistically significant as a prognostic factor (mOS ypT0: n.r., ypT1: 39.3, ypT2: n.r., ypT3: 44.6, ypT4: 19.9 months, p=0.006; R0-resected patients: ypT0: n.r., ypT1: 39.3, ypT2: n.r., ypT3: 46.9, ypT4: 16.1 months, p=0.025). However, ypT-category did not show the expected correlation with prognosis.

Within the individual pathological T-categories pT1 showed better prognosis than ypT0, both with significantly better outcome than ypT1 (mOS pT1: n.r., ypT0: n.r., ypT1: 39.3 months, p<0.001; R0: mOS pT1: n.r., ypT0: n.r., ypT1: 39.3 months, p<0.001), while there was no significant difference between pT2 and ypT2 (mOS pT2: 84.2 months, ypT2: n.r., p=0.287; R0: mOS pT2: 103.8 months, ypT2: n.r., p=0.385), pT3 and ypT3 (mOS pT3: 30.5, ypT3: 44.6 months, p=0.175; R0: pT3: 35.2, ypT3: 46.9 months, p=0.150), pT4 and ypT4 (mOS pT4: 19.1, ypT4: 19.9 months, p=0.915; R0: pT4: 19.1, ypT4: 16.1 months, p=0.656).

Conclusion: Pathological T-category can be confirmed as valid prognostic factor for patients after primary surgery. Although the extent of the primary tumor is statistically significant for neoadjuvantly treated patients, a lower ypT-category does not correlate with better prognosis. Especially T1-tumors seem to consist of two different entities: early esophagogastric cancer (pT1) with excellent prognosis and ypT1-carcinoma - which might have resulted from more advanced primary tumor stages by downstaging - with clearly worse outcome. Thus, prognostic value of ypT-category seems limited after neoadjuvant therapy. It should be reevaluated in a large patient collective and modified if needed.