Psychosocial Issues in Hereditary Colon Cancer Syndromes: Lynch Syndrome and Familial Adenomatous Polyposis
From the limited studies published to date, there appears to be interest in the use of ART for FAP.[19,20,27,29] However, actual uptake rates have not been reported.
Table 14. Summary of Studies Evaluating Interest in or Intention to Use Assisted Reproductive Technology (ART) for Familial Adenomatous Polyposis (FAP)a
GT = genetic testing; PGD = preimplantation genetic diagnosis; PND = prenatal diagnosis.
a Studies used a cross-sectional design and were conducted in the United Kingdom,[19,29] in the United States, and in the Netherlands..
b Indicates number of participants older than 18 y, unless otherwise specified.
|Study Population ||Nb||Interest or Intention in ART |
|FAP-affected individuals ||25||60% prenatal GT interest; 18% would consider aborting fetus if mutation was found |
|FAP-affected individuals ||62||65% prenatal GT interest; 24% would consider aborting fetus if mutation was found; 94% GT interest at birth |
|FAP-affected individuals ||20||95% prenatal GT interest; 90% would consider PGD; 75% would consider amniocentesis or chorionic villous sampling|
|FAP-affected individuals ||341||33% would consider PND for FAP; 30% would consider PGD; 15% felt terminating pregnancy for FAP was acceptable |
Participation in Genetic Counseling and Testing for Hereditary CRC
There are an increasing number of studies examining the actual uptake of genetic counseling and testing for LS (Table 15). Studies have included both colorectal cancer patients and unaffected, high-risk family members, recruited mainly from clinical settings and familial colon cancer registries. Most studies actively recruited participants for free genetic counseling and testing as part of research protocols.[10,30,31,32,33,34,35,36] Participation or uptake was defined at various points in the process, including genetic counseling before testing; provision of a blood sample for testing; and genetic counseling for disclosure of test results.
Table 15. Summary of Studies Evaluating Participation in Genetic Counseling and Testing for Hereditary Colorectal Cancer (CRC)a,b,c
FAP = familial adenomatous polyposis; FDR = first-degree relative; GC = genetic counseling; GT = genetic testing; HCCR = hereditary colon cancer registry; LS = Lynch syndrome.
a All studies used a prospective, observational design with the exception of one randomized trial evaluating two recruitment methods.
b All studies offered free GC and GT, with the exception of one study.
c All studies were conducted in the United States, with the exception of one Finnish study and one German study.[10,34]
d Indicates number of participants older than 18 y, unless otherwise specified.
e GC = participated in pretest or posttest genetic counseling; GT = participated in genetic testing and received results; GT (blood) = only provided blood sample for genetic testing.
f Unaffected = no previous diagnosis of colorectal cancer; affected = current or previous colorectal cancer diagnosis.
|Syndrome||Study Population||Nd||GC and GT Participatione|
|LS||Affectedf and unaffectedf members of four extended families from HCCR with a known LS mutation in kindred||219||59% pretest GC; posttest GC, GT |
|LS||Unaffected FDRs of CRC patients from HCCR ||505||21% pretest GC; 26% pending pretest GC; 15% GT (blood); 4% pending GT (blood) |
|LS||Affected and unaffected members of four extended families from HCCR with a known LS mutation in kindred ||208||47% pretest GC; 43% posttest GC, GT|
|LS||CRC patients from an oncology clinic and HCCR ||510||89% GT (blood) |
|LS||Unaffected members of 36 Finnish families with a known LS mutation in kindred ||446||78% pretest GC; 75% posttest GC, GT|
|LS and familial CRC||Affected and unaffected persons who underwent GC in a high-risk colon cancer clinic ||57 (LS); 91 (familial CRC)||LS: 14% posttest GC, GT|
|APCI130K: 85% posttest GC, GT |
|LS||CRC patients diagnosed age <60 y with affected FDR or second-degree relative, recruited through physicians ||101||47% pretest GC; 36% posttest GC, GT |
|LS||Unaffected FDRs of known LS mutation carriers ||111||51% pretest GC; 50% posttest GC, GT |
|LS||CRC patients from HCCR, relatives, and spouses ||140||26% pretest GC|
|FAP||Unaffected persons from HCCR age >5 y, with FAP-affected parent and known APC mutation in family ||57 adults; 38 minors||87% pretest GC; posttest GC, GT (82% adults; 95% minors)|