“Pathology characteristics, prognostic determinants and the outcome of patients diagnosed with colorectal adenocarcinoma at University Teaching Hospital of Kigali”

Abstract

Colorectal cancer (CRC) is the second most diagnosed cancer in female and the third in men worldwide, arising from the epithelium of the colon and the rectum. It is known that colorectal cancer is common in developed countries than in developing countries, the latter being mainly located in Africa. However, this 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 the cancer. The present study was conducted document the epidemiological and pathological characteristics and prognostics determinants of patients diagnosed with colorectal adenocarcinoma in Rwanda. This data would be used in deferent sectors to improve diagnostic, preventive and therapeutic interventions and reduce the CRC-associated morbidity and mortality. Ethical approval from the Institutional Review Board (IRB) of the University of Rwanda (UR) College of Medicine and Health Sciences (CMHS) and study permission from the study-hosting hospital were obtained prior to data collection. From the records in histopathology unity at University Teaching Hospital of Kigali (CHUK), 101 resection colorectal specimen were retrieved and all Hematoxylin and Eosin (H&E-stained) glass-slides were reviewed for diagnosis confirmation, tumor grading, tumor staging and other prognostic determinants including, margins status, inflammatory reaction, lympho-vascular and perineural invasion. Patients’ files were consulted for epidemiologic and clinical information. The mean age of participants was 54.26 (range 17–89) years. There was a slight female predominance (52.5%). Kigali City was over-represented (32.7% of participants). The main symptom was rectal bleeding (n=47 or 46.5%); the duration of symptoms was <6 months in 53 (52.5%) cases. The rectal adenocarcinoma NOS represented 40.6% of all CRC cases. The majority (n=56; 55.4%) of CRC diagnosed at CHUK showed microscopic tumor border with irregular infiltrating pattern and the conventional adenocarcinoma was the most frequent (n=61; 60.4%) histologic type. In addition, most tumors were of Grade II (n=55; 54.5%) while the most common stage was pT3N0 with a frequency of 21 (20.8%). Resection margins were free of tumor in 72 (71.3%) cases. Lympho-vascular invasion was present in 51 (49.5%) cases, while perineural invasion was seen in 29 (28.7%) cases. There was a high immune response in 72 (71.3%) cases. Of 101 patients diagnosed with CRC from the year 2014 to 2020, 56 (55.4%) were still alive at the end of the data collection, and 29.3% have overall survival of 5 years. The results of this study give a broad picture of colorectal adenocarcinoma patients in in Rwanda in terms of clinical pathologic characteristic and prognostic determinants and most of colorectal adenocarcinoma Rwandan patients are older (>50years). Inflammatory response, lympho-vascular invasion, perineural invasion and tumor border are some of prognostic determinants which have strong association with tumor differentiation which also affect the outcome of CRC patients.