The mean age of patients diagnosed with having tumor was 52.4; and 26.3% of them were less than 40 years old; this is comparable with a previous study performed in Ibn Sina Hospital at 2015,which found that colorectal cancer among young (< 40 years old) is 17.81%, and 43.84% was below 50 years. (14)
In Khartoum Teaching Hospital during the period 1st January 2000 to 31st December 2006; more than 34.5% of the study population was below the age of 40 years, and 17.3% were below 30 years. The peak frequency was at the age group (51–60) followed by the age group (61–70)(15) .
In our study 34.2% of the tumor patients were less than 50 years old, and among the whole study groups the frequency of participants with mutated APC gene who were less than 55 years old was 73.9% including tumor patients and others considered with high risk of cancer by having inflammatory mucosa or polypoid lesions.
The highest frequency of age among tumor patients was within the 50–60 age group, and in the polypoid lesions were within the 30–40 years old ,in the inflammatory group they were within the 40–50 years age group, this indicates that the first onset of cancer begins in old ages, and the polyps and inflammatory lesions begin within young ages ,that was also indicated by the noticed frequencies of young ages (> 40 year) among the different study groups which was, 26.3% among tumor group,34.2% in inflammatory lesions group, and 63.6% among polypoied lesions group .
The detection of cancer and the precursor lesions at early and more treatable stages is important for cure and survival. And it is previously known that the neoplastic polyps and inflammatory lesions are precursor lesions of the colorectal cancer. and nearly 95% of sporadic type of the cancer is developing from adenomas, and an individual with a history of adenomas has an increased risk of developing colorectal cancer, than individuals with no previous history of adenomas (7).
Regarding the anatomical site of lesions 84.2% of tumors were in the rectum this is agreed with Abdalla, et al. who found that rectal cancer represented half of the study population and rectal carcinomas are more common in men than in women (15) but disagree with who found that Colonic cancer constitutes 60.27% of the cases and rectal cancer found in 39.73% of cases(14).
Our findings revealed that 58.7% of patients were from outside of Khartoum this raises up the importance of improving health care centers in rural areas to avoid the late detection of cancers
and delay of treatment, although this was in disagreement with another study which found that the highest frequency were for those who are resident in Khartoum followed by western tribes(14) .
Our findings revealed that the western tribes were the highest frequency of geographic distribution in the tumor and polyps group but within the inflammation group the central tribes were the highest, this can indicate the type of diet or the mode of cancer within these different tribes, and the genetic factors.
Eight of the participants showed having history of colorectal cancer in their family within the first degree relatives, 62.5% were diagnosed with polypoid lesions, this ensures the high probability of developing cancers from the polyps.
The low rate of participants who revealed their family history of the cancer could be due to the lack of knowledge about the disease and the embarrassing factor-stigma that leads them to hide the history of the disease.
The significant statistical association that appeared in regard to the relation of family history with the geographic distributions is rising up the importance of mode of cancer in different ethnic groups and the increasing need for a wide range of studies to reveal the inherited genetic factor of the disease.