Colorectal cancer in Nigeria: 40 years on. A review.

This paper is a review of work done on colorectal cancer in Nigeria over the last 40 years showing geographic spread, age and sex ratios, predominant histopathology and paucity of polyposis coli syndromes. The male/female ratio is averagely equal, the peak age remains around 44 years, there is a significant subgroup of the under-30s and there are more rectal cancer cases than colon cancer cases. Of the colon cancer cases, the caecum seems to be the more favoured site. There seems to be quite a significant incidence of mucin-secreting adenocarcinoma subgroups which are said to carry a worse prognosis. Almost all the authors have stated the rarity of polyposis coli syndromes; a few have looked into the possibility of mismatch repair mutations as an aetiological factor.