Vol. 1, Issue 1 (2019)
The burden of colorectal cancers in Nigeria: Patterns and presentations in north-eastern Nigeria
Author(s): Aliyu S, Ningi AB, Babayo UD
Abstract: Background: Colorectal Cancer (CRC), previously considered a rarity in the African, especially, black African, has dramatically increased in incidence among indigenous African people over the last six decades. The West African subcontinent, Nigeria inclusive, has been affected by such increase. Recent reports from Ibadan and Ile-Ife Southwest of Nigeria has affirmed to this increase. Reports from Jos, North-central of Nigeria also indicated same. There is however, a dearth of recent data from the North-east of Nigeria highlighting the current state. Objectives: This study was designed to probe the current incidence, particularly, the age-related incidence and the anatomical site related burden of CRC. Patients and Methods: A prospective cross-sectional study of 65 patients that presented at the General surgery unit of the State Specialist Hospital Damaturu, Yobe state, Nigeria. It is an 8-year study of patients that presented with clinically and histologically diagnosed CRC, between 2006-2013. Patients’ characteristics studied included the age, gender, anatomical site of diagnosis, clinical stage, histopathologic diagnosis and grade, surgery and palliative care offered and the overall 5-year survival. Informed consent was obtained according to the Helsinki guidelines and Ethical clearance was given by the hospital management. All data obtained was assessed using the Statistical Package for Social Sciences, version 20.0 (IBM, Armonk, NY, USA). Results: A total of 65 patients were studied. 44(67.7%) were males and 21(32.3%) were females, with a male-female ratio of 2:1. The mean age was 50.5, with an age range of 16-79 years. The peak age of occurrence of CRC is 45-65 years. The most common of CRC in North-eastern Nigeria is rectal cancer (33.8%), Anorectal cancers (21.5%) and sigmoid colonic cancers at 15.4%. Right sided colonic tumours constituted 15.4% with predominance of caecal pole tumours (10.8%). The least common phenotypes were Transverse colonic (3.1%), ascending colonic, descending colonic and recto-sigmoid cancers, at 4.6% each. Only 49.2% of the patients presented early. About 41.5% presented with locally advanced disease, majority with malignant bowel obstruction. About 9.2% of the patients presented with metastatic disease. Adenocarcinoma is the most common histological variant (86.2%), followed by Gastro-intestinal Stromal Tumours (GIST) at 4.6%. all the remaining histological variants like, Lymphoma, Epidermoid Carcinoma, Cloacagenic Carcinoma, Small and Large cell carcinoma, occurred at almost same frequency of 1.5%. About 41.5% are well differentiated carcinoma and a relatively significant proportion are either poorly differentiated (16.9%) or other biologically aggressive subtypes; Mucin secreting at 10.8% and Signet ring type at 4.6%. Anterior resection with or without total Meso-rectal excision is the most common curative surgery (29.3%), Paul Muckliz colostomy is the most common procedure for those with locally advanced disease and Malignant bowel obstruction (10.8%). Palliative drainage with or without concurrent sclerotherapy was the most common procedure for those with malignant exudative fluid collections. Although, only 20% of the patients for 5 years and above after treatment, up to 87.4% were alive 3 years after treatment and majority are the young folks. Conclusion: There is an evident increase in the incidence of CRC in the North-east of Nigeria, like the rest of the country, with male preponderance and rectal cancer predominance. Colonic cancers are still rare as compared to the western world and is seen in much younger age group in North-eastern Nigeria. More than half of the patients presented with advanced disease.