Epidemioclinical Feature of Early-Onset Colorectal Cancer at-Risk for Lynch Syndrome in Central Iran


Background: Colorectal cancer (CRC) is becoming one of the most complicated challenges of human health,particularly in developing countries like Iran. In this paper, we try to characterize CRC cases diagnosed < age 50at-risk for Lynch syndrome within central Iran. Materials and
Methods: We designed a descriptive retrospectivestudy to screen all registered CRC patients within 2000-2013 in Poursina Hakim Research Center (PHRC), areferral gastroenterology clinic in central Iran, based on being early-onset (age at diagnosis ≤50 years) andAmsterdam II criteria. We calculated frequencies and percentages by SPSS 19 software to describe clinical andfamily history characteristics of patients with early-onset CRC.
Results: Overall 1,659 CRC patients were includedin our study of which 413 (24.9%) were ≤50 years at diagnosis. Of 219/413 successful calls 67 persons (30.6%)were reported deceased. Family history was positive for 72/219 probands (32.9%) and 53 families (24.2%) wereidentified as familial colorectal cancer (FCC), with a history of at-least three affected members with any type ofcancer in the family, of which 85% fulfilled the Amsterdam II Criteria as hereditary non-polyposis colorectalcancer (HNPCC) families (45/219 or 20.5%). Finally, 14 families were excluded due to proband tumor tissuesbeing unavailable or unwillingness for incorporation. The most common HNPCC-associated extracoloniccanceramong both males and females of the families was stomach, at respectively 31.8 and 32.7 percent. Themost common tumor locations among the 31 probands were rectum (32.3%), sigmoid (29.0%), and ascendingcolon (12.9%).
Conclusions: Given the high prevalence of FCC (~1/4 of early-onset Iranian CRC patients), it isnecessary to establish a comprehensive cancer genetic counseling and systematic screening program for earlydetection and to improve cancer prognosis among high risk families.