A new biomarker that predicts colonic neoplasia outcome in patients with hyperplastic colonic polyps
Menée sur des échantillons prélevés sur 74 patients présentant des polypes hyperplasiques, cette étude française évalue l'intérêt de la mesure du niveau d'expression de la progastrine pour prédire le développement de polypes adénomateux
The most frequently occurring lesions in the colon are the hyperplastic polyps (HP). HP have long been considered as lesions with no malignant potential and colonoscopy for these patients is not recommended. However recent works suggest that HP may represent precursor lesions of some sporadic colorectal cancers. Until now, none biomarker allows to identify the subset of HP that may have a malignant potential. Because the hormone precursor, progastrin has been involved in colon carcinogenesis, we investigated whether its expression in HP predicts occurrence of colonic neoplasm after resection of HP. We retrospectively analyzed progastrin expression in HP from 74 patients without history of colorectal pathology. In our study, 41% of patients presenting an initial HP subsequently developed adenomatous polyps, recognized as precursor lesions for colorectal adenocarcinomas. Progastrin was overexpressed in the HP in 40% of the patients. We showed a significant association between progastrin overexpression and shortened neoplasm-free survival (P= 0.001). Patients with high overexpression of progastrin had a 5 year neoplasm-free survival of 38% as compared to 100% for the patients with low progastrin expression. In addition, we established a predictive test based on progastrin staining and patient's age that predicts occurrence of neoplasm after developing a first HP with a sensitivity of 100% (95%CI: 79%-100%) and a specificity of 74% (51%-90%). We show that progastrin expression evaluation in HP is an efficient prognostic tool to determine patients with higher risk of metachronous neoplasms who could benefit from an adapted follow-up.
Cancer Prevention Research , résumé, 2012