Pilot Study on Low Penetrance Breast and Colorectal Cancer Predisposition Markers in Latvia

INTRODUCTION It has not been established whether CHEK2 and NOD2 variants are present in Latvia and whether inherited variation in these genes influences cancer risk in this population. AIM OF THE STUDY To evaluate the role of CHEK2 and NOD2 mutations in breast and colorectal cancers in the population of Latvia. MATERIALS AND METHODS Peripheral venous blood samples were collected from 185 breast cancer and 235 colorectal cancer consecutive hospital-based cases from 11/2003 to 06/2005. The population control group included blood samples from the clamped distal part of the umbilical cord from 978 consecutive anonymous newborns born between 03/2005 and 08/2005. All cases and controls were tested for the presence of NOD2 3020insC mutation and CHEK2 I157T mutation. RESULTS NOD2 3020insC was present in 7.7% (18/235) of CRC cancers, in 9.2% (17/185) of breast cancers and in 7.7% (75/974) of controls. CHEK2 I157T variant was found in 7.6% (14/185) of breast cancer cases, 10.2% (24/235) of colon cancer cases and in 6.4% (63/978) of population controls. NOD2 3020insC variant was associated with increased risk of breast cancer (OR = 2.5, p < 0.05) for cases diagnosed at age between 51 and 60 years. CHEK2 I157T variant was associated with increased risk of colorectal cancer (OR = 1.7, p < 0.05) with the highest OR = 2.0 for cases diagnosed at age >70 yrs. CONCLUSIONS NOD2 3020insC, CHEK2 I157T variants may be associated with increased risk of colorectal and breast cancers in Latvia.