COLORECTAL CANCER IN A SOUTH AFRICA URBAN SETTING - A PRELIMINARY ANALYSIS.

BACKGROUND: Colorectal cancer (CRC) is the second most common cancer in the world, with an estimated incidence in South Africa of 4-5% of all cancers . Studies show that whites account for the majority of South African patients but blacks for the majority of patients under the age of 50.

METHOD: This was a preliminary analysis of the first 113 patients enrolled in a prospective longitudinal study. All CRC patients presenting to the teaching hospitals of the Department of Surgery, University of the Witwatersrand were eligible for inclusion. Data was collected by an interviewer-administered questionnaire and entered into the CRC database. Statistical analysis was performed using SAS version 9.4 for Windows.

RESULTS: Patients presented to the three major centres in equal proportions with 68.2% in the public sector and 31.9% in the private sector. The mean age at presentation was 56 years (range 19-84, SD = 13.8), while 53.1% of the patients were male and 56.5% were black African. The mean age at presentation for black patients (53.7years, range 19-78, SD = 14.3) was significantly younger than for white patients (63.4years, range 43-84, SD = 12.6) (p = 0.0017). 83.2% of patients had at least some high school education and the majority (56.6%) lived in their own homes with access to indoor running water (92%) and sanitation (96.5%). All patients had access to electricity. 49.0% reported a family history of cancer, with mother (35%), sibling (33%), and father (25%) most frequently affected. The most common cancer in relatives was CRC (25%). There was a history of smoking in 36.7% of patients. BMI was normal in 45.7% of patients, while 44.8% were overweight. The three most common presenting complaints were weight loss (68.1%), per rectal bleeding (61.1%) and constipation (61.1%). There was no prior GIT diagnosis in 70.9% (n = 110). The most common finding on clinical examination was anaemia (20.0%). The majority of tumours were located in the rectum (49.1%), then the left (29.2 %) and right colon (16.8%).

CONCLUSION: The major findings were a tendency to younger age at presentation in black South Africans, and a predominance of tumours in the left colon and rectum. This is in line with previously published data showing a difference in age at presentation and site of tumour according to ethnicity. Risk factors such as smoking and obesity remain noteworthy even in a low-middle income country.