Is pretreatment endoscopic biopsy a good predictor of signet ring cell histology in gastric carcinoma?

Background: Signet ring cell (SRC) carcinoma is defined as an adenocarcinoma in which >50% of the total operative specimen consists of isolated or small groups of malignant cells containing intracytoplasmic mucins (hSRCs). We previously demonstrated that hSRCs are a predictor of poor prognosis with specific tumoral characteristics suggesting the need for a dedicated therapeutic strategy before surgery. However diagnostic accuracy and prognostic value of SRCs on pretreatment biopsies (bSRCs) is unknown. The aim of the study was to determine if bSRCs can accurately predict hSRCs and survival.

Methods: A retrospective analysis was performed among 254 patients with an adenocarcinoma. We performed pretreatment endoscopic biopsies and histopathologic analysis of the surgical specimen. Pretreatment endoscopic biopsy results were compared with definitive pathologic results and were correlated with long-term survival.

Results: From 254 patients enrolled, 96 had bSRCs (37.8%), and 101 (39.8%) had hSRCs. Pretreatment biopsy results were correct in 89 of 101 patients with hSRC (sensitivity 88.1%) and in 146 of 153 with histologic non-SRCs (hNSRCs) (specificity 95.4%). The positive and negative predictive values for the biopsies were 92.7, and 92.4%, respectively, with an overall accuracy of 92.5%. When compared to the biopsy results, non-SRCs (bNSRCs), bSRCs were associated with poorer survival and were identified as an independent factor for poor prognosis (hazard ratio 1.89 with 95% confidence interval 1.35 to 2.64, P < 0.001).

Conclusions: The presence of signet ring cells in samples obtained from routine pretreatment endoscopic biopsies accurately predicts SRC histology and poor prognosis. The specific therapeutic strategy can consequently be considered from the initial diagnosis.