Prevalence of colorectal cancer in relatives of Iranian patients diagnosed with colorectal cancer.
BACKGROUND
A high rate of colorectal cancer occurrence is established in individuals with a positive family history of this type of cancer.


OBJECTIVE
The aim of this study was to investigate the prevalence of colorectal cancer in first degree and second degree relatives of colorectal cancer patients.


METHODS
Family medical histories of 489 first degree relatives of colorectal cancer patients were obtained by a questionnaire. 249 average risk patients with no family history of colorectal cancer were included as control patients.


RESULTS
In our study from a total of 489 case patients, 153 (31.3%) had at least one close relative affected by colon cancer. Case-control analysis showed an odd ratio of 3.1 (95% CI, 2.07 to 6.27) for one and 5.7 (CI, 2.39 to 13.56) for two affected relatives. Cases with a positive family history had a 3.006 times greater risk in developing colorectal cancer if a first degree relative was affected comparing with a 4.9 times greater risk if a second degree family member was diagnosed with colorectal cancer. Our study indicated a higher risk for developing colorectal cancer in male family relatives 50 years and older. Rectal area was found the most tumor side affected in case and control patients.


CONCLUSIONS
First-degree relatives of patients with colorectal cancer had an increased risk of developing this type of cancer. The risk was greater when diagnosis was in male, elderly patients and other first-degree relatives were affected.
Fatemi
Seyed Reza
SR
Research Center for Gastroenterology and Liver Disease, Shahid Beheshti University of Medical Science, Tehran, Iran. Nedafat20@yahoo.com
Malek
Fatemeh Nemati
FN
Shivarani
Sepideh
S
Vahedi
Mohsen
M
Almasi
Shohreh
S
Maserat
Elham
E
Ebrahimi
Marjan
M
Zali
Mohammad Reza
MR
D016022:Case-Control Studies; D015179:Colorectal Neoplasms / Q000175:diagnosis* / Q000208:ethnology / Q000235:genetics*; D005190:Family / Q000208:ethnology*; D005260:Female; D020022:Genetic Predisposition to Disease; D006801:Humans; D007492:Iran; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D012307:Risk Factors; D011795:Surveys and Questionnaires