PurposeThe aim of this study was to evaluate the Immunoscore (IS) methodology as a prognostic marker of colorectal adenocarcinoma in Tunisian population. Tumor blocks were retrospectively collected from 106 patients with sporadic colorectal cancer.MethodsImmunohistochemical staining and images analysis software were used to quantify the density of CD3+ and CD8+ tumor-infiltrating lymphocytes in the center of the tumor and invasive margin.ResultsThe density of CD3+ and CD8+ was significantly associated with 5-year overall survival (P=0.001 and P=0.00098, respectively) and 5-year disease-free survival (P=0.0006 and P=0.0056, respectively). The earlier stage and the absence of vascular emboli showed a significant association with IS analysis. Cox multivariate regression analysis revealed that Immunoscore (from I0 to I4) was more significantly correlated with overall survival (P=0.00011) and disease-free survival (P=0.0008) than Tumor-Node-Metastasis (TNM) staging (P=0.057 and P=0.039, respectively). Patients with low IS were associated with inferior disease-free survival and overall survival, contrary to patients with high IS.ConclusionThis is the first study which evaluated the prognostic value of IS methodology in colorectal cancer in African and Arabic population. The IS methodology carries out in this study allows to estimate the risk of relapse in patients with colorectal cancer. Overall, our results support the implementation of the consensus Immunoscore as a new component for the classification of cancer, designated TNM-Immune.

COVID‐19 cases are increasing daily worldwide. With such emerging disease, the medical community should be aware of atypical clinical presentations in order to help with correct diagnosis, and to take the proper measures to isolate and treat patients to avoid healthcare professionals being infected and to limit its spread (SARS‐CoV‐2). Thrombogenesis in COVID‐19 has been described in few cases, but a thrombosis of a large digestive vessel has not been documented so far. Mesenteric ischemia due to an obstruction of a large vessel may be a new presentation of COVID‐19 infection.

The microsatellite instability (MSI) pathway is found in most cases of hereditary nonpolyposis colorectal cancer (HNPCC) and in 12 % of sporadic colorectal cancer (CRC). It involves inactivation of deoxyribonucleic acid mismatch repair (MMR) genes MLH1, MSH2, PMS2, and MSH6. MMR germline mutation detections are an important supplement to HNPCC clinical diagnosis. It enables at-risk and mutation-positive relatives to be informed about their cancer risks and to benefit from intensive surveillance programs that have been proven to reduce the incidence of CRC. In this study, we analyzed for the first time in Tunisia the potential value of immunohistochemical assessment of MMR protein to identify microsatellite instability in CRC. We evaluate by immunohistochemistry MMR protein expression loss in tumoral tissue compared to positive expression in normal mucosa. Immunohistochemistry revealed loss of expression for MLH1, MSH2, MSH6, and PMS2 in 15, 21, 13, and 15 % of cases, respectively. Here, we report a more elevated frequency of MSI compared to data of the literature. In fact, by immunohistochemistry, 70 % of cases were shown to be MSS phenotype, whereas 30 % of cases, in our set, were instable. Moreover, according to molecular investigation, 71 % of cases were instable (MSI-H) and remaining cases were stable (29 %). Thus, we found a perfect association between MMR immunohistochemical analyses and MSI molecular investigation. Immunohistochemical analysis of MMR gene product expression may allow one to specifically identify MSI phenotype of patients with colorectal carcinomas.

COVID-19 cases are increasing worldwide. With such emerging disease the medical community should be aware of atypical clinical presentations in order to help with correct diagnosis, and to take the proper measures to isolate and treat patients to avoid healthcare professionals being infected and to limit its spread (SARS-CoV-2).