Prospective impact of tumor grade assessment in biopsies on tumor stage and prognostic grouping in gastroesophageal adenocarcinoma: relevance of the seventh edition American Joint Committee on Cancer Staging Manual revision

Background: In the seventh edition of the American Joint Committee on Cancer (AJCC) staging system for esophageal cancer, tumor grade was introduced as an independent determinant of stage grouping in early stage tumors. With the significantly lower prognosis for poorly differentiated early stage adenocarcinomas, patients with these tumors may become candidates for neoadjuvant therapy given an accurate identification of these tumors with preoperative staging. The objective of the current study was to investigate the accuracy of preoperative histopathologic grading and the effect of preoperative grade on tumor stage/prognostic grouping.

Methods: Preoperative tumor grade was compared with postoperative tumor grade in 427 patients who underwent surgery without receiving neoadjuvant therapy for adenocarcinoma of the esophagus. The impact of preoperative tumor grade on stage/prognostic grouping was investigated.

Results: The overall accuracy of preoperative tumor grade assessment was 76% when unknown differentiation was regarded as well/moderately differentiated as recommended by the AJCC, whereas accuracy was 73% after the exclusion of tumors with unknown grade. In patients who have tumors classified as T1 or T2 and lymph node-negative (N0) (T1-T2N0) disease, 16% were assigned to a lower stage group based on preoperative pathology, whereas 5% were assigned to a higher stage group. In the T1-T2N0 group, sensitivity for detecting a poorly differentiated tumor was 0.43 (95% confidence interval [CI], 0.30-0.56), whereas specificity was 0.94 (95% CI, 0.90-0.98).

Conclusions: With increasing use of neoadjuvant therapy, the accuracy of preoperative biopsy assessment has become increasingly important. In the current study, the accuracy of preoperative tumor grade assessment was 73%, leading to changes in AJCC stage/prognostic group in 21% of patients with T1-T2N0 esophageal adenocarcinomas. The authors concluded that caution should be exhibited in staging patients with esophageal adenocarcinoma based on preoperative biopsy data.