BACKGROUND: Hereditary non-polyposis colorectal cancer (HNPCC) is an autosomal disease with a 68-82% lifetime risk of colorectal cancer (CRC). This study examined the phenotypic characteristics of CRC in Amsterdam criteria-positive Asian patients from the Singapore Polyposis Registry. METHODS: Hereditary non-polyposis CRC patients, defined by the Amsterdam I and II criteria, prospectively monitored in the Singapore Polyposis Registry over a 16-year period were reviewed. Clinical data were obtained from a computerized database and parameters, such as age of diagnosis, type and location of CRC, other associated cancers in the pedigree, cancer recurrence and survival were analysed. RESULTS: Fifty-two patients (31 men and 21 women) from 42 unrelated families, with a median age of 44.5 years (range 27-73 years), fulfilled either Amsterdam I or II criteria and were included in our analysis. The racial distribution was 91% (n = 47) Chinese and 9% (n = 5) Malays, with a median follow up of 44.9 months (range 2-183 months). Significantly, 69% of tumours in this Amsterdam-defined cohort were left sided, with most being sigmoid cancers. Sixty per cent of all the tumours presented at a late stage (Dukes' C or D). Left-sided tumours presented with more advanced Dukes' stage (P = 0.096) and a higher rate of metastatic disease (P = 0.08) compared with right-sided lesions. There were, however, no significant differences in either disease-free or overall survival between right-sided and left-sided tumours. CONCLUSION: This study emphasized the significant left-sided predominance of CRC in Amsterdam I and II-defined patients from our predominantly Chinese population, in contrast to those classically described in Lynch syndrome. Amsterdam criteria thus may not be suitable for diagnosing HNPCC in Asian populations and a greater emphasis should be made towards routine molecular diagnosis of mismatch repair gene defects in suspected HNPCC patients of Asian decent.
BACKGROUND: Hereditary non-polyposis colorectal cancer (HNPCC) is an autosomal disease with a 68-82% lifetime risk of colorectal cancer (CRC). This study examined the phenotypic characteristics of CRC in Amsterdam criteria-positive Asian patients from the Singapore Polyposis Registry. METHODS: Hereditary non-polyposis CRCpatients, defined by the Amsterdam I and II criteria, prospectively monitored in the Singapore Polyposis Registry over a 16-year period were reviewed. Clinical data were obtained from a computerized database and parameters, such as age of diagnosis, type and location of CRC, other associated cancers in the pedigree, cancer recurrence and survival were analysed. RESULTS: Fifty-two patients (31 men and 21 women) from 42 unrelated families, with a median age of 44.5 years (range 27-73 years), fulfilled either Amsterdam I or II criteria and were included in our analysis. The racial distribution was 91% (n = 47) Chinese and 9% (n = 5) Malays, with a median follow up of 44.9 months (range 2-183 months). Significantly, 69% of tumours in this Amsterdam-defined cohort were left sided, with most being sigmoid cancers. Sixty per cent of all the tumours presented at a late stage (Dukes' C or D). Left-sided tumours presented with more advanced Dukes' stage (P = 0.096) and a higher rate of metastatic disease (P = 0.08) compared with right-sided lesions. There were, however, no significant differences in either disease-free or overall survival between right-sided and left-sided tumours. CONCLUSION: This study emphasized the significant left-sided predominance of CRC in Amsterdam I and II-defined patients from our predominantly Chinese population, in contrast to those classically described in Lynch syndrome. Amsterdam criteria thus may not be suitable for diagnosing HNPCC in Asian populations and a greater emphasis should be made towards routine molecular diagnosis of mismatch repair gene defects in suspected HNPCC patients of Asian decent.
Authors: Yanqun Liu; Min Hoe Chew; Xue Wei Goh; Soo Yong Tan; Carol Tien Tau Loi; Yuen Ming Tan; Hai Yang Law; Poh Koon Koh; Choong Leong Tang Journal: PLoS One Date: 2014-04-07 Impact factor: 3.240