Table 16. Summary of Prospective Studies Evaluating Participation in Genetic Counseling and Testing for Hereditary Colorectal Cancer (CRC)a,b,c continued...
Gynecologic cancer screening in LS
A few studies have examined the use of screening for endometrial and ovarian cancers associated with LS. These studies have included relatively small numbers of women and suggest that screening rates for LS-associated gynecologic cancers are low before genetic counseling and testing. Two U.S. studies [41,77] reported that 14% of women with a family history of LS had undergone endometrial biopsy or 25% had undergone transvaginal ultrasound (TVUS) before genetic counseling and testing; among women who had seen a gynecologist in the preceding year, 50% had inadequate endometrial cancer screening.
Some studies suggest that women with a clinical or genetic diagnosis of LS do not universally adopt intensive gynecologic screening.[54,80] In a Belgian study, 85% of female mutation carriers and 27% of noncarriers underwent TVUS within the year following disclosure of genetic test results. One Australian longitudinal study examined gynecologic screening behaviors before testing and 1 year after disclosure of results. They found that 30% of women had undergone TVUS and 7% had undergone an endometrial biopsy before testing. Forty-seven percent of carriers and 10% of noncarriers reported having had a TVUS in the 12 months following test result disclosure, while 53% of carriers and 5% of noncarriers had undergone endometrial biopsy in that same period.
A cross-sectional study conducted in the Netherlands assessed gynecologic screening behaviors in LS mutation carriers, who were surveyed 6 months to 8.5 years after their genetic diagnosis. Seventeen percent of respondents reported that they had undergone gynecologic screening prior to undergoing genetic testing, and 69% reported they had undergone gynecologic screening since their genetic diagnosis (P < .001). However, the screening interval and specific gynecologic tests were not described.
Risk-reducing surgery for LS
There is no consensus regarding the use of risk-reducing colectomy for LS, and little is known about decision-making and psychological sequelae surrounding risk-reducing colectomy for LS.
Among persons who received positive test results, a greater proportion indicated interest in having risk-reducing colectomy following disclosure of results as compared with baseline. This study also indicated that consideration of risk-reducing surgery for LS may motivate participation in genetic testing. Before receiving results, 46% indicated that they were considering risk-reducing colectomy, and 69% of women were considering risk-reducing total abdominal hysterectomy (RRH) and risk reducing bilateral salpingo-oophorectomy (RRSO); however, this study did not assess whether persons actually followed through with risk-reducing surgery after they received their test results. Prior to undergoing LS genetic counseling and testing, 5% of cancer-unaffected individuals at risk of a MMR mutation in a longitudinal study reported that they would consider colectomy, and 5% of women indicated that they would have an RRH and an RRSO, if they were found to be mutation-positive. At 3 years following disclosure of results, no participants had undergone risk-reducing colectomy.[54,76] Two women who had undergone an RRH before genetic testing underwent RRSO within 1 year after testing, however, no other female mutation carriers in the study reported having either procedure at 3 years following test result disclosure.