Dr. Deogratias Ruhangaza

Background: Of the cancers diagnosed in Rwanda, stomach cancer is one of the most encountered. In fact, Rwanda belongs to the region where it is most incident in Africa. Most of the patients present with advanced disease. Studies showed that some gastric cancers overexpress Human Epidermal Growth Factor Receptor 2 (HER2/neu) protein and can be treated with Herceptin/Tras-tuzumab. This targeted therapy improves survival in patients with advanced disease. We conducted a study on Immunohistochemical profile of HER2/neu in gastric adenocarcinomas at two main Rwandan tertiary centers. Methodology: We tested for HER2/NEU in gastric adenocarcinomas diagnosed at University Teaching Hospital of Kigali (CHUK) and University Teaching Hospital of Butare (CHUB). Demographic and pathologic parameters were collected. Immunohistochemistry (IHC) for HER2/neu using c-erb/HER-2/neu (clone SP3) Rabbit Monoclonal antibody was done. Using the guidelines established by Hoffman et al., the agreed score between 2 Rwandan pathologists and 1 USA pathologist was considered each time. Data were entered and statistically analyzed using SPSS 22. Descriptive statistical analysis method was used. P-value calculated with Chi-square analysis for positive vs negative and equivocal negative to correlate HER2/neu overexpression with other variables across both hospitals. Results: A total of 286 cases were tested. HER2/neu overexpression (score 3+ or positive) was found in 29 cases (10.1%). 8 cases (2.8%) were equivocal negative (score 2+) while 249 cases (87.1%) were negative (score 0 and 1+). Conclusion: HER2/neu is overexpressed in a subset of gastric cancers in Rwanda, a phenomenon that has been reported in other areas of the world. Testing for HER2/neu could identify patients who would get a targeted treatment with Herceptin. Keywords: Gastric, Cancer, Rwanda, HER2, Immunohistochemistry

Worldwide, colorectal cancer (CRC) is the second most diagnosed cancer in female and the third in men, arising from the epithelium of the colorectum. It is known that colorectal cancer is common in developed countries than in developing countries which may be due to inaccurate data on the existence of the disease in that region combined with embracing western lifestyle expressed by the current trend of changes in cultural, social, and lifestyle practices playing a major part in the etiology of CRC. The aim of this study was to document epidemiological, pathological characteristics, and prognostics determinants of patients diagnosed with CRC in Rwanda. The data from patients’ files and reviewed glass slides for 101 cases all from Kigali University Teaching Hospital (CHUK) were statistically analyzed and patient characteristics were described as mean and frequency accordingly. Comparisons were performed using chi square tests, Fisher’s exact test and odds ratio with 95% confidence interval (CI). Survival curves were plotted using the Kaplan–Meier method, and log-rank test was used to assess the statistical differences in the observed survival curves by each categorical variable. A P value < 0.05 was considered statistically significant. Statistical analyses were performed using Statistical Product and Service Solutions (SPSS), GraphPad Prism, and MedCalc, accordingly. Mean age of the participants was 54.26 years, the main symptom was rectal bleeding (46.5%), rectal adenocarcinoma NOS represented 40.6%, conventional adenocarcinoma was 60.4%, most tumors were of Grade II (54.5%), most common stage was pT3N0 (20.8%), resection margins were free at 71.3%, lympho-vascular invasion was 49.5% of cases, a high immune response was in 71.3% of cases and of 101cases, and 55.4% were still alive at the end of the data collection, with 29.3% of patients have overall survival of 5 years. Prognostic determinants also affect the outcome in this study and overall survival period was 3 years for CRC diagnosed in Rwanda.

Abstract Objectives Breast cancer immunohistochemistry (IHC) biomarker testing is limited in low-resource settings, and an alternative solution is needed. A point-of-care mRNA STRAT4 breast cancer assay for ESR1, PGR, ERBB2, and MKi67, for use on the GeneXpert platform, has been recently validated on tissues from internationally accredited laboratories, showing excellent concordance with IHC. Methods We evaluated STRAT4/IHC ESR1/estrogen receptor (ER), ERBB2/human epidermal growth factor receptor 2 (HER2) concordance rates of 150 breast cancer tissues processed in Rwanda, with undocumented cold ischemic and fixation time. Results Assay fail/indeterminate rate was 2.6% for ESR1 and ERBB2. STRAT4 agreement with ER IHC was 92.5% to 93.3% and 97.8% for HER2, for standard (1x) and concentrated (4x) reagent-conserving protocols, respectively. Eleven of 12 discordant ER/ESR1 cases were ESR1- negative/IHC-positive. These had low expression of ER by IHC in mostly very small tumor areas tested (7/12; &lt;25 mm2). In two of three discordant HER2 cases, the STRAT4-ERBB2 result correlated with the subsequent fluorescence in situ hybridization (FISH) result. STRAT4-ERBB2 results in 9 of 10 HER2-IHC equivocal cases were concordant with FISH. Conclusions The STRAT4 assay is an alternative for providing quality-controlled breast cancer biomarker data in laboratories unable to provide quality and/or cost-efficient IHC services.