Susan Armel

The incidence of pancreatic cancer in BRCA1 and BRCA2 mutation carriers

Background:Germline mutations in BRCA1 and BRCA2 predispose to pancreatic cancer. We estimated the incidence of pancreatic cancer in a cohort of female carriers of BRCA1 and BRCA2 mutation. We also estimated survival rates in pancreatic cancer cases from families with a BRCA mutation.Methods:We followed 5149 women with a mutation for new cases of pancreatic cancer. The standardised incidence ratios (SIR) for pancreatic cancer were calculated based on age group and country of residence. We also reviewed the pedigrees of 8140 pedigrees with a BRCA1 or a BRCA2 mutation for those with a case of pancreatic cancer. We recorded the year of diagnosis and the year of death for 351 identified cases.Results:Eight incident pancreatic cancer cases were identified among all mutation carriers. The SIR for BRCA1 carriers was 2.55 (95% CI=1.03–5.31, P=0.04) and for BRCA2 carriers was 2.13 (95% CI=0.36–7.03, P=0.3). The 5-year survival rate was 5% for cases from a BRCA1 family and 4% for cases from a BRCA2 family.Conclusion:The risk of pancreatic cancer is approximately doubled in female BRCA carriers. The poor survival in familial pancreatic cancer underscores the need for novel anti-tumoural strategies.

Rapid progression of prostate cancer in men with a BRCA2 mutation.

Men with BRCA2 mutations have been found to be at increased risk of developing prostate cancer. There is a recent report that BRCA2 carriers with prostate cancer have poorer survival than noncarrier prostate cancer patients. In this study, we compared survival of men with a BRCA2 mutation and prostate cancer with that of men with a BRCA1 mutation and prostate cancer. We obtained the age at diagnosis, age at death or current age from 182 men with prostate cancer from families with a BRCA2 mutation and from 119 men with prostate cancer from families with a BRCA1 mutation. The median survival from diagnosis was 4.0 years for men with a BRCA2 mutation vs 8.0 years for men with a BRCA1 mutation, and the difference was highly significant (P<0.01). It may be important to develop targeted chemotherapies to treat prostate cancer in men with a BRCA2 mutation.

Incidence of colorectal cancer in BRCA1 and BRCA2 mutation carriers: results from a follow-up study.

Background:The BRCA1 and BRCA2 genes confer increased susceptibility to breast and ovarian cancer and to a spectrum of other cancers. There is controversy regarding the risk of colorectal cancer conferred by germline mutations in these two genes.Methods:We followed 7015 women with a BRCA mutation for new cases of colorectal cancer. Incidence rates in carriers were compared with population-specific incidence rates, and standardised incidence ratios (SIRs) were estimated. The expected numbers of cancers were computed by multiplying person–years at risk by the appropriate age-, sex- and country-specific incidence rates from the five countries.Results:Twenty-one incident colorectal cancer cases were observed among all mutation carriers, compared with 23.6 cases expected. The SIR for BRCA1 carriers was 0.92 (95% confidence interval (CI), 0.54–1.40, P=0.7) and for BRCA2 carriers was 0.82 (95% CI, 0.30–1.81, P=0.7). The SIR for colon cancer was 3.81 (95% CI 1.77–7.23) for women below the age of 50 years (both genes combined) and was 0.60 (95% CI 0.33–1.00) for women aged 50 years and above.Conclusion:The risk of colorectal cancer is increased in female carriers of BRCA1 mutations below the age of 50 years but not in women with BRCA2 mutations or in older women.

Frequency of premature menopause in women who carry a BRCA1 or BRCA2 mutation

OBJECTIVE To evaluate the impact of carrying a BRCA1 or BRCA2 mutation on the probability of experiencing premature natural menopause. DESIGN Observational study. SETTING Patients in an academic research environment. PATIENT(S) Women who carry a BRCA1 or BRCA2 mutation (case subjects) and women who do not carry a mutation (control subjects). INTERVENTION(S) Survey about reproductive history administered on study entry and every 2 years thereafter. MAIN OUTCOME MEASURE(S) The impact of carrying a BRCA mutation on age at menopause and other factors, including parity, age at first birth, age at last birth, and self-reported fertility. RESULT(S) A total of 908 matched pairs were identified. The mean age at natural menopause was 48.8 years for BRCA1 carriers, 49.2 years for BRCA2 carriers, and 50.3 years for control subjects. Women who carried a BRCA mutation had parity similar to noncarriers and were as likely as noncarriers to have a child after age 35 years. Similar proportions reported a history of fertility problems (12.5% vs. 13.7%) and use of fertility medication (6.0% vs. 7.0%). CONCLUSION(S) Women who carry a BRCA mutation experience menopause earlier, on average, than women who do not have a mutation, but the difference is small and does not appear to affect fertility.

Development and testing of a decision aid for breast cancer prevention for women with a BRCA1 or BRCA2 mutation

For women who carry a mutation in BRCA1 or BRCA2, the risk of breast cancer is up to 87% by the age of 70. There are options available to reduce the risk of breast cancer; however, each option has both risks and benefits, which makes decision making difficult. The objective is to develop and pilot test a decision aid for breast cancer prevention for women with a BRCA1 or BRCA2 mutation. The decision aid was developed and evaluated in three stages. In the first stage, the decision aid was developed and reviewed by cancer genetics experts. The second stage was a review of the decision aid by women with a BRCA1 or BRCA2 mutation for acceptability and feasibility. The final stage was a pre‐test–post‐test evaluation of the decision aid. Twenty‐one women completed the pre‐test questionnaire and 20 completed the post‐test questionnaire. After using the decision aid, there was a significant decline in mean decisional conflict scores (p = 0.001), a significant improvement in knowledge scores (p = 0.004), and fewer women uncertain about prophylactic mastectomy (p = 0.003) and prophylactic oophorectomy (p = 0.009). Use of the decision aid decreased decisional conflict to levels suggestive of implementation of a decision. In addition, knowledge levels increased and choice predisposition changed with fewer women being uncertain about each option. This has significant clinical implications as it implies that with greater uptake of cancer prevention options by women with a BRCA1 or BRCA2 mutation, fewer women will develop and/or die of hereditary breast cancer.

Bilateral Oophorectomy and Breast Cancer Risk in BRCA1 and BRCA2 Mutation Carriers.

Background: Whether oophorectomy reduces breast cancer risk among BRCA mutation carriers is a matter of debate. We undertook a prospective analysis of bilateral oophorectomy and breast cancer risk in BRCA mutation carriers. Methods: Subjects had no history of cancer, had both breasts intact, and had information on oophorectomy status (n = 3722). Women were followed until breast cancer diagnosis, prophylactic bilateral mastectomy, or death. A Cox regression model was used to estimate the hazard ratios (HRs) and 95% confidence intervals (CIs) of breast cancer associated with oophorectomy (coded as a time-dependent variable). All statistical tests were two-sided. Results: Over a mean follow-up of 5.6 years, 350 new breast cancers were diagnosed. Among women with a BRCA1 or BRCA2 mutation, oophorectomy was not associated with breast cancer risk compared with women who did not undergo an oophorectomy. The age-adjusted hazard ratio associated with oophorectomy was 0.96 (95% CI = 0.73 to 1.26, P = .76) for BRCA1 and was 0.65 (95% CI = 0.37 to 1.16, P = .14) for BRCA2 mutation carriers. In stratified analyses, the effect of oophorectomy was statistically significant for breast cancer in BRCA2 mutation carriers diagnosed prior to age 50 years (age-adjusted HR = 0.18, 95% CI = 0.05 to 0.63, P = .007). Oophorectomy was not associated with risk of breast cancer prior to age 50 years among BRCA1 mutation carriers (age-adjusted HR = 0.79, 95% CI = 0.55 to 1.13, P = .51). Conclusions: Findings from this large prospective study support a role of oophorectomy for the prevention of premenopausal breast cancer in BRCA2, but not BRCA1 mutation carriers. These findings warrant further evaluation.

Family history as a predictor of uptake of cancer preventive procedures by women with a BRCA1 or BRCA2 mutation

Women with a BRCA1 or BRCA2 mutation are at an elevated risk of developing breast and ovarian cancer; however, it is unclear to what extent family history influences the uptake of cancer prevention options.Women with a BRCA1/2 mutation completed a follow‐up questionnaire that assessed uptake of cancer preventive options. The pedigree of each woman was reviewed, and information was recorded on cancers diagnosed in relatives. Five hundred and seventeen women were included in the study. Women with a sister with breast cancer were more likely to have a prophylactic mastectomy than those without a sister with breast cancer [odds ratios (OR) = 2.4, p = 0.003]. Uptake of prophylactic mastectomy was significantly lower in women with a mother with ovarian cancer compared with those whose mother did not have ovarian cancer (OR = 0.4, p = 0.01). Having a mother or sister with ovarian cancer significantly predicted the uptake of prophylactic oophorectomy (OR = 1.6, p = 0.04). Women with a BRCA2 mutation were less likely to have a prophylactic oophorectomy than those with a BRCA1 mutation (OR = 0.49, p = 0.0004). Among women with a BRCA1 or BRCA2 mutation, family history predicts the uptake of prophylactic mastectomy and prophylactic oophorectomy.

Uptake of clinical genetic testing for ovarian cancer in Ontario: A population-based study

BACKGROUND Approximately 13% of ovarian cancers in Canada are attributable to a mutation in BRCA1 or BRCA2. In 2001, genetic testing for BRCA1 and BRCA2 became freely available to all women in Ontario with a diagnosis of invasive ovarian cancer. It is unknown what proportion of women with ovarian cancer receive genetic testing as a result of this recommendation. METHODS Patients in Ontario who had been diagnosed with epithelial ovarian cancer from 2002 to 2004 were identified using the Ontario Cancer Registry. Information was collected on demographic and risk factors, including information on previous testing for BRCA1 and BRCA2. Women were asked to provide a blood sample for genetic testing or to provide a genetic test result if clinical testing had been done. Genetic testing for BRCA1 and BRCA2 mutations was conducted on all blood samples. RESULTS Of the 416 women, 80 women (19%) had undergone previous clinical genetic testing for BRCA1 and BRCA2. Of these 80 women, 30% had a positive genetic test result, compared to 5% of 336 women who had not had clinical genetic testing (p<0.0001). Sixty percent of all mutations were identified within this group of 80 women. CONCLUSIONS Genetic testing is available in Ontario to all women with invasive ovarian cancer. However, only a small proportion of women are being referred for testing. This study suggests that increased public awareness directed at physicians and at women with cancer may expand the use of genetic testing.

The risk of breast cancer in women with a BRCA1 mutation from North America and Poland

Women with a BRCA1 mutation face a high lifetime risk of breast cancer. It is unknown to what extent environmental factors modify the inherent genetic risk. If women from different countries, but with similar mutations, experience different levels of cancer risk, nongenetic risk modifiers are likely to be present. Study subjects were a cohort of 1477 women with a BRCA1 mutation, from Canada (n = 358), the United States (n = 256) and Poland (n = 863). The women were followed for a mean of 4.3 years and 130 incident cases of breast cancer were recorded. Annual cancer incidence rates were calculated, and based on these, penetrance curves were constructed for women from North America and Poland. In a Cox proportional hazards model, residence in Poland, versus North America, was associated with an adjusted hazard ratio of 0.54 (95% CI 0.34‐0.86; p = 0.01). The risk of breast cancer to age 70 was estimated to be 49% for women from Poland and 72% for women from North America. Among women with BRCA1 mutations, the risk of breast cancer in women who reside in Poland is less than that of women who reside in North America. The reasons for the difference are unknown, but this observation suggests that environmental factors or genetic modifiers are important in determining risk.

Keeping it simple: Genetics referrals for all invasive serous ovarian cancers

OBJECTIVE In the province of Ontario, all women diagnosed with invasive serous ovarian cancer are eligible for genetic testing for mutations in the BRCA1 and BRCA2 genes. This study aimed to determine the proportion of these women who are seen for genetic counseling and to identify potential predictors and barriers to having genetic counseling. METHODS All women who were diagnosed with invasive serous ovarian cancer and had genetic counseling at Princess Margaret Hospital (PMH) between 2002 and 2009 were identified. Logistic regressions and trend analyses explored age at diagnosis, year at diagnosis, and the time between diagnosis and genetic counseling. Genetic counseling outcomes were also examined. RESULTS Of 623 women diagnosed with invasive serous ovarian cancer, 144 (23%) were seen for genetic counseling. As age at diagnosis increased, the likelihood of genetic counseling decreased (p=0.005). With a more recent date of diagnosis, the probability of having genetic counseling increased (p=0.032) while the time to genetic counseling decreased (p=0.001). Of women who pursued genetic testing, 31% were found to have a BRCA1 or BRCA2 mutation, 16% of whom had no family history of breast or ovarian cancer. CONCLUSIONS Despite the availability of genetic testing, only a small proportion of women with invasive serous ovarian cancer were seen for genetic counseling. Over time, an improvement in the proportion of women being seen for genetic counseling was noted; however barriers to seeing women with a later age at diagnosis or those with no family history of breast or ovarian cancer clearly exist.