Replication Protein A (RPA1, RPA2 and RPA3) expression in gastric cancer: correlation with clinicopathologic parameters and patients' survival.

PURPOSE: Replication Protein A (RPA) consists of three subunits (RPA1, RPA2 and RPA3) essential for all major DNA metabolic pathways. Although RPA seems to be a promising therapeutic target, its role in human cancers has not been fully elucidated. This is the first study investigating the expression of all the three RPA subunits in a series of 74 resected gastric carcinomas and analyzing the possible correlations with clinicopathologic parameters (histological type, grade, lymphovascular invasion, lymph node status and disease stage), Ki-67 proliferative index, Topoisomerase IIa expression and patients' survival. METHODS: Immunohistochemistry using monoclonal antibodies. Univariate and multivariate statistical analysis. RESULTS: All the three subunits showed widespread nuclear expressions in gastric carcinomas with significant associations among their expressions. RPA2 demonstrated higher expression levels in low grade carcinomas and a gradual significant decrease from N0 to N3 and from stage I to stage IV carcinomas. All the three subunits were statistical significantly more abundant in lymph node negative and earlier stage (stage I & II) gastric carcinomas. No associations were established among RPAs and the proliferative marker Ki-67. In patients with positive lymph nodes and advanced tumor stage, RPA1 expression seemed to predict a better overall survival implying a probable predictive role. CONCLUSIONS: The widespread expression of RPA(1-3) suggests one or more roles in gastric cancer. Their presence in earlier stage tumors probably offers an opportunity for early targeted therapy. Their probable predictive value in node positive and advanced stage tumors needs further investigation with respect to specific chemotherapeutic treatments.

Unusual case of intraluminal cecal recurrence of a low grade appendiceal mucinous neoplasm (LAMN)-Case report and brief literature review.

INTRODUCTION: Appendiceal mucinous neoplasms exhibit a wide spectrum of clinical behavior, ranging from neoplasms which are relatively slow-growing but with considerable risk for recurrence and eventual death and those neoplasms that are highly aggressive with increased likelihood of early death. Clinical behavior depend mainly on mucinous neoplasms grading and staging. PRESENTATION OF CASE: We present the incidental finding of a mucinous appendiceal neoplasm in a 52 years old woman during her follow up for an operated breast carcinoma. The patient underwent appendectomy and a low grade appendiceal mucinous neoplasm (LAMN) confined into the appendiceal wall was diagnosed. Resection margin showed fibrous replacement of the appendiceal wall and some acellular intraluminal mucin. Three months later the tumor recurred inside the cecal lumen and a right hemicolectomy was performed showing again a LAMN confined into the bowel wall. DISCUSSION: According to the latest AJCC eighth edition patients with pTis LAMN, as in our case, (LAMN confined to the muscularis propria after histologic examination of the entire appendix) have essentially no risk of recurrence. Moreover, some authors suggest follow up for LAMN confined into the appendix even with a positive surgical margin. CONCLUSION: Rarely, LAMN may recur in the form of a polypoid protrusion into the cecal lumen and this recurrence may originate from the buried stump of the appendix, especially when the surgical margin is positive.