Borrmann type IV gastric cancer should be classified as pT4b disease.

Background: The impact of macroscopic pathologic features of primary tumor that could be obtained preoperatively on pT classification has not been reported so far. The aim of this study was to investigate the feasibility of incorporation of Borrmann type IV gastric cancer into the pT classification.

Materials And Methods: Clinicopathologic and prognostic data of 1622 patients with advanced gastric cancer who underwent radical surgery were retrospectively studied.

Results: Of 1622 patients, 135 (8.32%) patients were classified as having Borrmann type IV gastric cancer. We first confirmed that Borrmann type IV gastric cancer was one of the independent prognostic factors for patients with advanced gastric cancer who underwent radical surgery. Interestingly, we found that overall survival of patients with Borrmann type IV gastric cancer could be clearly distinguished by pN classification and pathological TNM stage but not by pT classification. Importantly, further analysis demonstrated that the prognosis of Borrmann type IV gastric cancers was homogeneous with that of pT4b cancers but poorer than pT2, pT3, pT4a cancers. Therefore, we proposed a novel pT classification in which pT4b disease was defined as cancers that were Borrmann type IV or those that had invaded adjacent structures. Two-step multivariate analysis demonstrated that the novel pT classification was more suitable for prognostic assessment than the original classification.

Conclusions: Classifying Borrmann type IV gastric cancer as pT4b disease improves pT classification prediction of prognosis in patients with advanced gastric cancer after radical surgery.