Correction: Risk of colorectal cancer for carriers of a germ-line mutation in POLE or POLD1.

The abstract to this article contained errors in the Results and Conclusions section. The corrected sections are shown below.

Risk of colorectal cancer for carriers of a germ-line mutation in POLE or POLD1.

BACKGROUND: Germ-line mutations in the exonuclease domains of the POLE and POLD1 genes are associated with an increased, but yet unquantified, risk of colorectal cancer (CRC). METHODS: We identified families with POLE or POLD1 variants by searching PubMed for relevant studies prior to October 2016 and by genotyping 669 population-based CRC cases diagnosed in patients under 60 years of age, from the Australasian Colorectal Cancer Family Registry. We estimated the age-specific cumulative risks (penetrance) using a modified segregation analysis. RESULTS: We observed 67 CRCs (mean age at diagnosis = 50.2 (SD = 13.8) years) among 364 first- and second-degree relatives from 41 POLE families, and 6 CRCs (mean age at diagnosis = 39.7 (SD = 6.83) years) among 69 relatives from 9 POLD1 families. We estimated risks of CRC up to the age of 70 years (95% confidence interval) for males and females, respectively, to be 28% (95% CI, 10­42%) and 21% (95% CI, 7­33%) for POLE mutation carriers and 90% (95% CI, 33­99%) and 82% (95% CI, 26­99%) for POLD1 mutation carriers. CONCLUSION: CRC risks for POLE mutation carriers are sufficiently high to warrant consideration of colonoscopy screening and implementation of management guidelines recommended for MSH6 mutation carriers in cases of Lynch syndrome. Refinement of estimates of CRC risk for POLD1 carriers is needed; however, clinical management recommendations could follow those made for POLE carriers.

Tumor testing to identify lynch syndrome in two Australian colorectal cancer cohorts.

BACKGROUND AND AIM: Tumor testing of colorectal cancers (CRC) for mismatch repair (MMR) deficiency is an effective approach to identify carriers of germline MMR gene mutation (Lynch syndrome). The aim of this study was to identify MMR gene mutation carriers in two cohorts of population-based CRC utilizing a combination of tumor and germline testing approaches. METHODS: Colorectal cancers from 813 patients diagnosed with CRC < 60 years of age from the Australasian Colorectal Cancer Family Registry (ACCFR) and from 826 patients from the Melbourne Collaborative Cohort Study (MCCS) were tested for MMR protein expression using immunohistochemistry, microsatellite instability (MSI), BRAFV600E somatic mutation, and for MLH1 methylation. MMR gene mutation testing (Sanger sequencing and Multiplex Ligation Dependent Probe Amplification) was performed on germline DNA of patients with MMR-deficient tumors and a subset of MMR-proficient CRCs. RESULTS: Of the 813 ACCFR probands, 90 probands demonstrated tumor MMR deficiency (11.1%), and 42 had a MMR gene germline mutation (5.2%). For the MCCS, MMR deficiency was identified in the tumors of 103 probands (12.5%) and seven had a germline mutation (0.8%). All the mutation carriers were diagnosed prior to 70 years of age. Probands with a MMR-deficient CRC without MLH1 methylation and a gene mutation were considered Lynch-like and comprised 41.1% and 25.2% of the MMR-deficient CRCs for the ACCFR and MCCS, respectively. CONCLUSIONS: Identification of MMR gene mutation carriers in Australian CRC-affected patients is optimized by immunohistochemistry screening of CRC diagnosed before 70 years of age. A significant proportion of MMR-deficient CRCs will have unknown etiology (Lynch-like) proving problematic for clinical management.