Ms. Kohlmann is genetic counselor in the Division of Medical Genetics at the University of Michigan Medical Center in Ann Arbor.

Dr. Peterson is assistant professor in the Department of Behavioral Science at the University of Texas MD Anderson Cancer Center in Houston.

Acknowledgments:The authors report no financial, academic, or other support of this work. 


 

Abstract

Hereditary nonpolyposis colorectal cancer (HNPCC) and familial adenomatous polyposis (FAP) are the most common forms of hereditary colon cancer. Due to the increased cancer risks associated with these conditions, the need for intensive cancer screening and management programs, and disease implications for patients and families, both affected individuals and their family members have unique needs for medical information and psychosocial support. To address their medical and psychosocial needs, genetic counseling should be offered to persons who are concerned about a possible inherited risk for HNPCC or FAP, and who may be considering genetic testing for these conditions. The purpose of this article is to provide an overview of the HNPCC and FAP syndromes and relevant psychosocial issues. The need to address complex medical and psychosocial issues related to these syndromes also will be illustrated through the presentation of two genetic counseling case scenarios.

 

Introduction

Colorectal cancer (CRC) is the third most common form of cancer and the second leading cause of cancer-related deaths in the United States.1 Approximately 20% of CRC cases occur in individuals who have a family history of the disease. Hereditary nonpolyposis colorectal cancer (HNPCC) and familial adenomatous polyposis (FAP) are the two most common forms of hereditary colon cancer as well as the most studied. Both conditions are associated with an increased lifetime risk for CRC and other cancers. At-risk individuals are advised to follow rigorous cancer screening and management regimens because of the increased likelihood that they may develop polyps or colon cancer at a younger age than the general population. Lack of information and poor adjustment to an HNPCC or FAP diagnosis may interfere with adherence to management recommendations and limit communication about these conditions amongst other at-risk family members.

It is important for healthcare providers in primary care settings to have an understanding of the medical, social, and psychological implications of hereditary colon cancer syndromes so that they can effectively and responsibly integrate this information into their current practice.

This article will provide an overview of HNPCC and FAP as well as psychological and behavioral issues associated with genetic counseling and testing for these hereditary cancer syndromes. Genetic counseling case studies are used to illustrate psychosocial issues experienced by individuals and families at risk for these syndromes, and how such issues may influence adjustment and cancer risk-management decisions.

 

Overview of Hereditary Nonpolyposis Colon Cancer and Familial Polyposis

Two well-characterized hereditary CRC syndromes account for 5% to 10% of all CRC cases: HNPCC, associated with germline mutations in mismatch repair genes (hMSH1, hMLH2, hMSH6, PMS1, PMS2) and FAP, caused by germline mutations in the APC gene.2 An inherited mutation in one of these genes is suspected in a family when CRC (or other syndrome-related cancers) is present in successive generations and at earlier ages compared with the general population, and when individuals have more than one primary cancer associated with these syndromes. Children of mutation carriers have a 50% chance of inheriting the mutation themselves, and both genders can inherit these conditions equally. A distinct feature of FAP is the development of multiple colorectal polyps, often beginning in puberty, and the disease can be diagnosed clinically on this basis.

HNPCC confers a 70% to 80% lifetime risk for developing colon cancer, with an average onset at 44 years of age.3-6 Women with HNPCC have a 40% to 60% lifetime risk for endometrial cancer and a 6% to 13% risk for ovarian cancer.7-10 HNPCC is also associated with an increased risk for biliary tract, small bowel, upper urinary tract, and gastric cancers.9,10

If polyps are not removed in persons with FAP, the lifetime risk of colon cancer approaches 100%, with an average onset of 42 years of age. FAP also is associated with benign features outside of the digestive system including epidermal cysts, osteomas, congenital hypertrophy of retinal pigmented epithelium (CHRPE), dental abnormalities, and desmoid tumors. FAP also confers an increased risk for upper gastrointestinal cancers, hepatoblastoma, brain tumors, and thyroid cancers. Some families have a milder expression of FAP with few polyps and later age of onset.11,12 Although this attenuated form of FAP is associated with increased cancer risks, its diagnosis may be missed due to the lack of classic presentation. It has been reported that 22% of FAP cases have no family history of the disease and result from a spontaneous APC gene mutation.13

When genetic testing is offered to a group of persons with family histories suggestive of HNPCC or FAP, it is optimal to begin testing in a person who has been diagnosed with a syndrome-associated cancer or who has a clinical diagnosis of FAP. Doing so increases the likelihood of finding a disease-predisposing mutation if one is present in the family. If a mutation is found in the index case, then genetic testing for the presence of this specific mutation can be offered to other at-risk family members. It is possible that a known deleterious mutation may not be detected in an index case with a family history suggestive of HNPCC, or in an index case with multiple polyps characteristic of FAP, because of limitations in current technology. When this occurs, families are still considered to be at high risk for a hereditary CRC syndrome and are recommended to follow high-risk screening and prevention recommendations. A negative test result is considered conclusive only if the deleterious mutation has been previously identified in an affected member.

Genetic testing for hereditary cancers can identify persons who would benefit from increased screening and surveillance because they carry a disease-predisposing mutation. Conversely, genetic testing can identify persons who are not genetically at high risk for developing cancer, and as such are recommended to follow screening guidelines for the general population. Recommended screening and prevention options for HNPCC and FAP are presented in the accompanying table.14-16 Recent evidence indicates that chemopreventive agents may play a role in the management of FAP. However, at this time these medications are not a replacement for screening and prophylactic surgery.17

 

Genetic testing for adult-onset disorders such as HNPCC is discouraged for persons under 18 years of age, because the medical and psychosocial benefits of testing are not realized until adulthood. Ethical concerns about testing children include the inability of minors to give informed consent, as well as the possibilities that children found to be carriers may be stigmatized, may be given fewer opportunities, and may not receive appropriate counseling about their results.18 On the other hand, genetic testing is offered to families with children at risk of FAP, generally beginning at 10 years of age, because surveillance for this condition is warranted at an early age.19

 

Genetic Counseling for Hereditary Colon Cancer

Professional organizations have issued statements to guide the implementation of genetic counseling and testing for hereditary cancers in clinical and research settings to assure that individuals seeking these services receive sufficient information to make an informed decision about testing, screening, and prevention options.20-22 Genetic counseling should be conducted with persons who are concerned about a possible inherited risk for cancer and/or who may be considering cancer genetic testing, because the interpretation of genetic test results is complex.22 A study of persons undergoing commercial genetic testing for FAP found that less than 20% of them were offered genetic counseling prior to testing.23 Only 17% of persons in that study gave written informed consent prior to testing and results were misinterpreted by the physician in 32% of cases.23

The process of genetic counseling is ideally carried out in a manner that combines education about genetic concepts with counseling techniques.24 Genetic counselors gather detailed information about individuals’ personal and family history of cancer in order to accurately assess their inherited cancer risk, and to educate them about options for early detection and prevention, which may include genetic testing. An initial genetic counseling visit may include discussion of the family history, providing information about personal and familial cancer risks, and the option of genetic testing, assessment of the client’s motives, coping strategies, and family strategies.

Although there are potential medical and psychological benefits to defining one’s inherited cancer risk through genetic testing, there also are significant risks and limitations to the process. Genetic counselors generally discuss the option of genetic testing in a nondirective manner, and encourage individuals to make a decision about testing based on the risks and benefits relevant to their personal and family situation. The importance of adhering to age- and risk-appropriate screening guidelines is emphasized to all individuals regardless of their eligibility or decision regarding genetic testing.

If a client decides to pursue genetic testing, results are given during a follow-up genetic counseling session. Clients at risk for hereditary CRC may benefit from ongoing interactions with a genetic counselor to reassess changes in the family history and to stay informed about new early detection and prevention developments. Continued support also may help assure that information about the diagnosis is shared with other at-risk relatives, and can help families cope with medical and psychosocial issues that may develop over time (eg, a new cancer diagnosis in the family, reproductive considerations, screening for children).

 

Psychosocial Impact of Genetic Testing for Hereditary Colon Cancer

Studies that have evaluated interest and participation in hereditary CRC genetic testing have found that individuals are motivated by recommendations from their doctor or genetic counselor, beliefs in the benefits of testing, and a desire to gain information that may reduce uncertainty about their condition, help their children, reduce the need for frequent screening, and facilitate lifestyle or health-habit decisions.25-28 Few studies have evaluated psychological or behavioral outcomes of testing for HNPCC or FAP. Based on validated distress measures, the limited evidence suggests that undergoing genetic counseling and testing for other hereditary cancers does not cause significant psychological morbidity for most individuals.29-32

Notification that one does not carry a hereditary cancer mutation has been associated with a reduction in distress from the pre- to post-test time periods, suggesting that receipt of true negative test results confers a psychological benefit.31,32 However, subgroups of individuals may be at higher risk for experiencing adverse emotional outcomes from testing, and may benefit from increased support. Individuals who have higher levels of distress, lower quality of life and social support, and concerns about their ability to cope with their mutation carrier status prior to testing may be at greatest risk for experiencing distress after disclosure of positive genetic test results.33-35 Carriers of cancer-predisposing mutations reported higher levels of psychological distress compared with noncarriers,31,32,36 and one study37 suggested that mutation carriers who did not expect to receive positive genetic test results experienced higher distress after disclosure. Additional research is needed to evaluate the impact of carrier status notification on psychological adjustment as well as adherence to screening and surveillance recommendations.

Psychological adjustment to the genetic counseling and testing process may be influenced by family members’ experiences as well. A study of children who had undergone FAP genetic testing found that mutation carriers and noncarriers scored within normal ranges on measures of distress and behavioral problems. However, children with an FAP-affected mother were more distressed compared with children of unaffected mothers.38 Persons seem generally willing to share test results with other family members and follow through in doing so,28,39 although cancer patients have expressed concern about having the responsibility of passing on this information to others in their family.39 A limitation of studies to date is that they have focused on outcomes of the genetic counseling and testing process, and have not evaluated the impact of hereditary cancers on persons who have not come forward for counseling and testing. Future research should attempt to close this gap and further assess the impact of hereditary cancer on the family as well as the individual level.

 

Case Studies in Genetic Counseling for Hereditary Colon Cancer

The following cases illustrate psychosocial issues and counseling decisions faced by families with HNPCC and FAP. These cases represent two families who have participated in research studies for HNPCC and FAP. Pedigrees were modified to maintain confidentiality.

 

Case 1

Anna was diagnosed with CRC at age 35 years, and underwent HNPCC genetic counseling and testing as part of a research study. During a genetic counseling session to disclose results indicating that she was a mutation carrier, the genetic counselor began by reviewing the family history (Figure 1). Anna reported that the family had no contact with her sister, Nancy, and that she had “heard through the grapevine” that Nancy had been diagnosed with CRC. This information cued the genetic counselor to further explore issues about family communication during the session. Anna indicated that she planned to share the test results with her brothers and her mother, but not with Nancy. She stated that since Nancy had excluded herself from the family it would be Nancy’s own responsibility to seek out information about her cancer risk.

 

The genetic counselor further explored implications of Anna’s estrangement from her sister by role-playing scenarios focusing on possible outcomes from sharing or not sharing her test results with Nancy. Through this exercise, Anna expressed concern about her at-risk niece, Erica, regardless of her feelings about her relationship with Nancy. Anna stated that knowledge of her own test results could benefit Erica, who was approaching the age when high-risk screening options would be recommended. Although Anna still did not feel comfortable contacting her sister, a plan was developed to have her brother, who still had some contact with Nancy, share the information from genetic testing with her.

This case illustrates the important issue that Anna’s genetic test results also had medical implications for her family. In cases such as this the genetic counselor is faced with the issue of one’s duty to warn other at-risk family members. This matter has been addressed through case law, which has indicated that the clinician does have a duty to inform patients of familial risks.40 However, whether solely warning the patient fulfills this duty or whether and how family members can be notified without breaking patient confidentiality has not been clarified. Thus, genetic counselors and other healthcare providers face challenges regarding their roles and boundaries in disseminating genetic information to at-risk family members.

In families who express communication barriers due to estrangement, distance, or other reasons, simply informing the client about genetic risks for family members may not assure that the information is conveyed. Dissemination of genetic information in families may be limited, even in the absence of identified communication barriers, because of concerns about arousing relatives’ anxiety or other reasons.41 As a result, family members may not convey hereditary cancer risk information in a manner that emphasizes the importance of this information for one’s health or that prompts action among relatives. Any discomfort with communicating genetic information may be magnified when there are other problems with family relationships. Genetic counseling strategies that may facilitate the dissemination of risk information within families include role-playing to increase clients’ comfort in explaining information, providing written information to share with other relatives, identifying relatives who can help communicate the information, and preparing clients to cope with possible reactions from family members.

This case also illustrates the potential risk to Anna’s own emotional well-being if she chooses not to share genetic information with her sister because of their prior conflicts. One goal of genetic counseling is to help clients cope with immediate issues resulting from a genetic diagnosis and to help them anticipate feelings that they may experience in the future as a result of the genetic condition in their family, including the potential impact on future generations.42 Anna was disturbed by the thought of her niece developing cancer. Through genetic counseling, Anna better understood the possible decisional outcomes if she withheld or shared her test results with her sister and identified factors important to that decision.

 

Case 2

Lisa was diagnosed with FAP when she was 18 years of age. She underwent prophylactic colectomy at 25 years of age and subsequently developed a desmoid tumor, which required several additional surgeries and chemotherapy (Figure 2). Lisa requested genetic counseling to discuss the option of genetic testing for her children, and canceled several counseling appointments before she was finally seen. During the session, she appeared very apprehensive about having genetic testing for her daughters when they reached 10 years of age, and the genetic counselor explored reasons for her reluctance. The counselor discussed common concerns expressed by parents with FAP, including feelings of guilt about passing on a genetic condition, worries about the impact of testing on their relationship with their children, and worries about children’s ability to cope with an FAP diagnosis. Lisa acknowledged her fear that an FAP diagnosis might negatively affect her relationship with her daughters. The counselor asked Lisa to describe her feelings toward her mother, Maria, for passing this condition on to her. Lisa indicated that she understood that her mother could not control the path of inheritance. However, she stated that she had blamed Maria for her health problems when she was a child and young adult, and did not think that she could cope with her daughters having similar feelings towards her. Lisa suggested that having more information about the cause of her disease and talking with other teenagers who had FAP may have helped her cope better with her condition. Lisa and the counselor discussed how such strategies could be implemented for her children as they undergo screening and genetic testing.

 

In addition to her worries about her children, it became clear during the session that Lisa was having difficulties coping with her own disease. Her desmoid tumor was not responding well to treatment and Lisa expressed bitterness because she was the only person in the family to have developed this FAP-related complication. She and the counselor discussed reestablishing her relationship with her mother as another source of support as her daughters approached ages when genetic testing is recommended. Through counseling, Lisa identified how her difficulties in coping with her own disease may affect how she would be able to cope with the additional stress of learning her children were positive. This issue was important to explore because the early onset of FAP requires that parents take an active role in their children’s care.

An educational approach in genetic counseling can convey information, but it may not truly facilitate understanding of the personal implications of a genetic diagnosis.21 In addition to educating Lisa about her children’s risk of inheriting an FAP-predisposing mutation, it was important for the genetic counselor to address her feelings of guilt, anger, and fear related to her own experience with this condition as well as the experiences she anticipated for her children. Parents may avoid having their children evaluated at an appropriate age because of an underlying fear that their children might blame them for having passed on a genetic condition. Indeed, Lisa’s worries about her children’s reaction may have been part of the reason she missed several genetic counseling appointments prior to being seen by the counselor.

This case also illustrates the importance of evaluating clients’ personal experiences with genetic conditions as part of the genetic counseling process. Both FAP and HNPCC can exhibit different phenotypes among family members who carry the same disease-predisposing mutation, which in turn may carry different psychosocial implications for those affected. Lisa’s other mutation-positive family members underwent colectomy for FAP and had no further complications, in contrast to her own experience with desmoid tumors and additional treatment. Perception of one’s own disease also may be affected by whether other affected family members survived their cancers or whether they had a caregiver role for an affected family member.

Lisa’s distress regarding her disease and her children was not resolved through genetic counseling alone, and further psychological counseling was recommended. Follow-up genetic counseling visits were recommended to reassess Lisa’s feelings about having her children evaluated, and to establish a medical management plan to assure that her children receive the care they need.

 

Conclusion

Families affected by HNPCC and FAP face a challenging array of medical, psychological, and social issues. It is important for primary healthcare providers to be aware of these issues and to integrate knowledge about hereditary cancer syndromes into their current practice and care of families who may potentially be at risk for HNPCC or FAP. In addition to assuring that at-risk individuals receive appropriate referrals for genetic counseling and medical care related to the management of these conditions, primary care providers also could provide encouragement for adherence to screening recommendations and support for medical decisions that may impact both patients and their families.

This article emphasizes the importance of utilizing genetic counselors and other genetics professionals to educate families about their hereditary CRC risks and risk management options. As illustrated by the cases presented here, it is crucial to address the psychosocial issues that may arise during these discussions to facilitate ability in both individuals and families to effectively cope with and successfully manage their disease. Ongoing support from genetic counselors and other healthcare providers can be instrumental in helping persons adjust to new developments that may affect their own or their family members’ risks.   PP

 

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