Hereditary Nonpolyposis Colorectal Cancer (HNPCC): A Pilot Study Assessing Understanding and Attitudes Towards Prenatal Testing

Abstract

Purpose: Hereditary Nonpolyposis Colorectal Cancer Syndrome (HNPCC) is the most common hereditary cancer syndrome accounting for 2-3% of colorectal cancer (CRC). Patients with HNPCC gene mutations have a 70-80% chance of developing CRC. Little is known about the attitudes of individuals with HNPCC towards prenatal diagnosis. We conducted a pilot study to evaluate HNPCC patients' understanding of their disease and assess their attitudes towards various modalities of prenatal testing. Methods: 12 individuals with HNPCC were educated on the currently available options for prenatal diagnosis of HNPCC including amniocentesis, chorionic villous sampling (CVS), and preimplantation genetic diagnosis (PGD). They were then given a 40-item survey on personal and family history related to HNPCC, demographics, and attitudes toward prenatal testing of their offspring. Results: Nine women and 3 men participated. Mean age at diagnosis was 42.8 years. 83% were Caucasian and 8% African American. 83% were married. 67% had children none of which were yet tested for HNPCC. 83% of the subjects knew there was a 50% risk of their offspring being affected with HNPCC. None were aware of prenatal testing options for HNPCC prior to the study. 100% were of the opinion that prenatal testing options should be discussed and offered to all with a HNPCC gene mutation. 58% would consider undergoing prenatal testing. Of these 100% would consider amniocentesis or PGD and 86% would consider CVS. More subjects were aware of amniocentesis (83%) than PGD or CVS (50%, 25% respectively). 83% felt that all modalities were ethically sound. 50% of the subjects felt that learning the fetus was unaffected with HNPCC was the greatest advantage of PGD. The possibility of complications (58%), or concerns regarding procedure success (33%), seemed to be the greatest disadvantage. 25% of the subjects felt that a HNPCC diagnosis influenced their reproductive decisions. The most important reason against prenatal testing was the difficulty in subsequent decisions making regarding termination. Religious or personal beliefs played little role in decision-making. Conclusion: The majority of HNPCC affected patients surveyed were aware of the autosomal dominant inheritance pattern of HNPCC. All patients felt prenatal testing options should be offered routinely. Though all patients in this study had seen genetic counselors in the past, none were aware of prenatal testing options for their disease prior to this study. This pilot study demonstrates the importance of addressing prenatal testing options in HNPCC patients. Future studies should be conducted to assess if prenatal counseling referral should be required as standard of care in all patients diagnosed with HNPCC.