Ovarian cancer family and prophylactic choices

Specialist oncological surgery for removal of the ovaries and fallopian tubes in BRCA1 and BRCA2 pathogenic variant carriers may reduce primary peritoneal cancer risk to very low levels

Risk‐reducing bilateral salpingo‐oophorectomy (RRBSO) is highly effective for the prevention of high‐grade serous ovarian cancer (HGSOC) in BRCA1/2 pathogenic variant carriers (PVCs), but does not completely eliminate future risk of primary peritoneal cancer (PPC). The requirement to completely remove fallopian tubes at RRBSO and carefully exclude occult cancer/serous tubal intraepithelial carcinoma (STIC) lesions may not have been appreciated historically. We calculated rates of HGSOC and PPC in confirmed BRCA1/2 PVCs registered on the regional database in those who did (cases) and did not (controls) undergo RRBSO after genetic testing. Expected annual rates of ovarian/peritoneal cancer were 1% for BRCA1 ≥ 35 years and 0.5% for BRCA2 ≥ 45 years. Follow‐up before 35/45 years was “risk free” and lead time excluded RRBSO <35 years and <45 years for BRCA1 and BRCA2, respectively. Women were followed from personal mutation report (controls) or RRBSO (cases) to death, ovarian/peritoneal cancer or last follow‐up, whichever was sooner. In total, 891 cases (BRCA1 = 468, BRCA2 = 423) and 1302 controls had follow‐up ≥35 years (BRCA1 = 736) and ≥45 years (BRCA2 = 566), respectively, over a total of 7261.1 risk eligible years (mean = 8.15 years). Twenty‐one occult ovarian cancers were found at RRBSO (2.4%), 16 at stage 1. Post RRBSO, 56.97 ovarian/peritoneal cancers were expected but only 3 were observed (HR = 0.053; 95% CI = 0.013‐0.14), with combined Kaplan‐Meier analysis HR = 0.029 (95% CI = 0.009‐0.100, P < .001). Risk reduction was greater in specialist (HR = 0.03; 95% CI = 0.001‐0.13) compared to non‐specialist centres (HR = 0.11; 95% CI = 0.02‐0.37) (P = .07). In controls, 23.35 ovarian/peritoneal cancers were expected with 32 observed (HR = 1.37; 95% CI = 0.95‐1.91). RRBSO <35/<45 years reduces the risk of ovarian/peritoneal cancer by 95% in BRCA1/2 PVCs and may be greater in specialist centres.

What's new?

Women who carry genetic variants in BRCA1/2 that are linked to high‐grade serous ovarian cancer are advised to undergo risk‐reducing prophylactic bilateral salpingo‐oophorectomy (RRBSO). RRBSO, however, is associated with a significant residual risk of primary peritoneal cancer (PPC). Here, the rate of PPC following prophylactic surgery for high‐grade serous ovarian cancer was investigated among 2,193 BRCA1/2 mutation carriers who had undergone RRBSO. Estimates indicate that prophylactic surgery reduced the overall risk of PPC by 95 percent, a far greater reduction than previously described. Residual risk was lowest when RRBSO was carried out at specialist centers compared to non‐specialist centers.

Screening women at high risk of breast cancer on the basis of evidence

Geneticists are able to identify the risk of breast cancer. Strategies on offer include prevention, early diagnosis by screening, and prophylactic surgery. This paper analyses the evidence for offering screening. The radiation dose of mammography has been measured, but the risk is not fully known. Mammography screening of women of 40-50 years in the normal population has known effect. Little evidence is available for women under 40 years or for women with genetic susceptibility to breast cancer. Dense parenchymal pattern is associated with high grade cancers, and is both a risk factor and a reason for impaired screening sensitivity. Whether this applies to younger women or women at high risk is speculative. The pathological features of the cancers in gene carriers show differences from those occurring in normal women. This work should be correlated with imaging features. There is no literature to support the use of newer imaging methods in these women. Ultrasound and MRI avoid radiation and may be useful in dense breasts. SestaMIBI and PET scanning are not yet mature enough for screening, and may never have such a role. Any newer modality must be subjected to a formal randomised trial before being offered to screen women at high risk.

A qualitative study of the information needs of high-risk women undergoing prophylactic oophorectomy

This qualitative study sought to determine the information needs of high-risk pre-menopausal women who had undergone prophylactic bilateral oophorectomy to manage their inherited risk of ovarian cancer. In-depth interviews were carried out with 23 high-risk women following surgery. Although the benefit of risk reduction was perceived as out weighing the costs of surgery, many women reported that they would have liked more information about the physical and emotional after-effects of oophorectomy prior to and following surgery. The analysis identified five different types of information needed by women making surgical decisions, comprising information about ovarian function and the menopause, hormone replacement therapy (HRT), surgical procedures, convalescence and the risk of inheriting a genetic mutation and developing cancer. It is suggested that, in addition to genetic counselling for hereditary ovarian cancer, women should receive information about both the costs and benefits of prophylactic oophorectomy, and should have access to gynaecology nurse specialists both before and after surgery.

Investigation and management of patients at high risk of developing cancer

Recent developments in cancer genetics have revealed genes that render individuals susceptible to cancer. These families have a unique set of new problems and benefits that must be thought through for the potential good to be accrued from these discoveries. Individual patients seek early diagnosis and prevention strategies that challenge the limits of current knowledge. Some available methods have not yet been evaluated. There is a need for the evidence to support plans of care, and consistency is required from one centre to the next in the advice given. These familial cancers are often different from the more common sporadic cases, and so traditional treatments need to be tested again in the context of the new genetic knowledge. Three groups of cancers, breast, ovary and colon, have been used to illustrate the issues surrounding these high risk families, their investigation and care. In applying new strategies to these patients, ethical issues arise that are new to the medical world, and must be considered by the lay public. It is up to the medical profession, patients and society to use this knowledge to give benefit to a vulnerable group, and not to give unaffordable hopes and unnecessary anxieties.

Ascertainment of familial ovarian cancer in the Aberdeen Genetic Clinic

Ovarian cancer is the fifth most common malignancy in women in the UK. Patients with a family history including ovarian cancer make up nearly 15% of family cancer referrals to the Genetic Clinic in Aberdeen. To date, only one pedigree has been suitable for linkage studies, which has enabled us to target screening more accurately at those people at highest risk. Following discovery of a strong candidate for the BRCA1 gene, direct mutation testing may soon be possible. People who seek testing will require further counselling. Therefore we anticipate an increased demand on both clinical and laboratory resources, but more accurate ascertainment of high risk subjects should lead to more appropriate targeting of screening services.

A sociobehavioural perspective on genetic testing and counselling for heritable breast, ovarian and colon cancer

Testing for susceptibility to heritable breast, ovarian and colon cancer has unique psychosocial costs. Negative test results may not be sufficient to relieve anxiety, and positive results can cause sufficient distress to compromise patient compliance with surveillance and risk reduction measures. More needs to be learned about how sociocultural factors affect the understanding of risk, how decisions to undergo testing are made and how information about increased risk affects family dynamics. As the demand for testing and counselling grows, health care providers will be faced with new challenges and dilemmas. A better understanding of genetics by the public is needed to mitigate deterministic attitudes that can lead to the neglect of health promotion. Also of concern are the socioeconomic implications of being identified as having a high risk for heritable cancer and the dangers inherent in using genetics to explain sociological phenomena. Health care providers must take the lead in ensuring that developments in genetics are used to the benefit of all.

Is early detection of ovarian cancer possible?

Advances in medical technology have led to potentially useful techniques for the early detection of epithelial ovarian cancer. Early detection of ovarian cancer is crucial for survival as women found to have Stage I or II disease have a 5-year survival of 90% and 70%, respectively, whereas those with advanced disease (Stage III and IV) have a survival of approximately 20%. The circulating tumour marker CA-125 has been extremely useful in following women known to have epithelial ovarian cancers. It has been employed in differentiating benign tumours from malignancies, and is now being tested in a variety of programmes for its role in the early detection of ovarian cancer. The application of endovaginal ultrasound and colour Doppler flow techniques to early detection of ovarian cancer have resulted in several large series identifying ovarian cancer in 1:1000 to 1:2000 postmenopausal women screened. However, a high false positivity rate persists using CA-125 and ultrasound techniques alone or in sequence. Developments in molecular genetics may be extremely useful in evaluating women with inherited susceptibilities for this disease, but this probably represents only about 3% of the population of the women who develop epithelial ovarian cancer. The cost-benefit analysis of isolated screening for epithelial ovarian cancer using CA-125 and ultrasound techniques, even in women at high risk for the disease, would suggest that such screening is not cost-effective at this time.

Ovarian carcinoma. A review of the significance of familial risk factors and the role of prophylactic oophorectomy in cancer prevention

Women with a family history of ovarian cancer are at increased risk of ovarian cancer. Prophylactic oophorectomy (PO) remains the only effective method of ovarian cancer prevention. This study reviewed current data on the significance of family history and how prophylactic oophorectomy should be used in different risk groups. Approximately 7% of ovarian cancer patients have a positive family history of whom 3-9% may eventually manifest certain hereditary cancer syndromes. Women in direct genetic lineage of family cancer syndromes have up to a 50% lifetime risk of ovarian cancer. Because of the high risk, PO is indicated for women with familial cancer syndromes after childbearing or between the ages of 35-40 at the latest. The majority of women with a positive family history of ovarian cancer do not have one of the recognized syndromes. Women with one or two affected relatives have an increased lifetime risk of ovarian cancer from a baseline of 1.6 to 5-7%. This risk is not high enough to warrant PO for a large number of women. After being properly informed, the patient still chooses surgical prevention, she then receives PO. For women without a family history of ovarian cancer, the role of PO remains controversial. Assuming an annual incidence of 22,000 new cases of ovarian cancer, it is estimated that at least 1000 may be prevented if PO is diligently practiced during hysterectomy. Despite ovarian and breast cancer prevention, PO would lead to shorter life expectancy if estrogen therapy compliance were less than perfect. Thus, the decision on PO as a concurrent procedure should depend on the individual patient and her ability to comply with lifelong estrogen therapy.