Timing of oral contraceptive use and the risk of breast cancer in BRCA1 mutation carriers.

It is not clear if early oral contraceptive use increases the risk of breast cancer among young women with a breast cancer susceptibility gene 1 (BRCA1) mutation. Given the benefit of oral contraceptives for the prevention of ovarian cancer, estimating age-specific risk ratios for oral contraceptive use and breast cancer is important. We conducted a case-control study of 2,492 matched pairs of women with a deleterious BRCA1 mutation. Breast cancer cases and unaffected controls were matched on year of birth and country of residence. Detailed information about oral contraceptive use was collected from a routinely administered questionnaire. Conditional logistic regression was used to estimate the odds ratios (OR) and 95 % confidence intervals (CI) for the association between oral contraceptive and breast cancer, by age at first use and by age at diagnosis. Among BRCA1 mutation carriers, oral contraceptive use was significantly associated with an increased risk of breast cancer for women who started the pill prior to age 20 (OR 1.45; 95 % CI 1.20-1.75; P = 0.0001) and possibly between ages 20 and 25 as well (OR 1.19; 95 % CI 0.99-1.42; P = 0.06). The effect was limited to breast cancers diagnosed before age 40 (OR 1.40; 95 % CI 1.14-1.70; P = 0.001); the risk of early-onset breast cancer increased by 11 % with each additional year of pill use when initiated prior to age 20 (OR 1.11; 95 % CI 1.03-1.20; P = 0.008). There was no observed increase for women diagnosed at or after the age of 40 (OR 0.97; 95 % CI 0.79-1.20; P = 0.81). Oral contraceptive use before age 25 increases the risk of early-onset breast cancer among women with a BRCA1 mutation and the risk increases with duration of use. Caution should be taken when advising women with a BRCA1 mutation to take an oral contraceptive prior to age 25.

Duration of tamoxifen use and the risk of contralateral breast cancer in BRCA1 and BRCA2 mutation carriers.

Women with a mutation in BRCA1 or BRCA2 face a lifetime risk of breast cancer of approximately 80 %. Tamoxifen treatment of the first cancer has been associated with a reduction in the risk of a subsequent contralateral cancer. We studied 1,504 women with a known BRCA1 or BRCA2 mutation, 411 women with bilateral breast cancer (cases) and 1,093 women with unilateral breast cancer (controls) in a matched case-control study. Control women were of similar age and had a similar age of diagnosis of first breast cancer as the cases. For each woman who used tamoxifen, the starting and stopping dates were abstracted and the duration of tamoxifen use was calculated. Three hundred and thirty-one women had used tamoxifen (22 %); of these 84 (25 %) had completed four or more years of tamoxifen, the remainder stopped prematurely or were current users. For women with up to 1 year of tamoxifen use, the odds ratio for contralateral breast cancer was 0.37 (95 % CI 0.20-0.69; p = 0.001) compared to women with no tamoxifen use. Among women with 1-4 years of tamoxifen use the odds ratio was 0.53 (95 % CI 0.32-0.87; p = 0.01). Among women with four or more years of tamoxifen use the odds ratio was 0.83 (95 % CI 0.44-1.55; p = 0.55). Short-term use of tamoxifen for chemoprevention in BRCA1 and BRCA2 mutation carriers may be as effective as a conventional 5-year course of treatment.

Mutations in myosin light chain kinase cause familial aortic dissections.

Mutations in smooth muscle cell (SMC)-specific isoforms of α-actin and ß-myosin heavy chain, two major components of the SMC contractile unit, cause familial thoracic aortic aneurysms leading to acute aortic dissections (FTAAD). To investigate whether mutations in the kinase that controls SMC contractile function (myosin light chain kinase [MYLK]) cause FTAAD, we sequenced MYLK by using DNA from 193 affected probands from unrelated FTAAD families. One nonsense and four missense variants were identified in MYLK and were not present in matched controls. Two variants, p.R1480X (c.4438C>T) and p.S1759P (c.5275T>C), segregated with aortic dissections in two families with a maximum LOD score of 2.1, providing evidence of linkage of these rare variants to the disease (p = 0.0009). Both families demonstrated a similar phenotype characterized by presentation with an acute aortic dissection with little to no enlargement of the aorta. The p.R1480X mutation leads to a truncated protein lacking the kinase and calmodulin binding domains, and p.S1759P alters amino acids in the α-helix of the calmodulin binding sequence, which disrupts kinase binding to calmodulin and reduces kinase activity in vitro. Furthermore, mice with SMC-specific knockdown of Mylk demonstrate altered gene expression and pathology consistent with medial degeneration of the aorta. Thus, genetic and functional studies support the conclusion that heterozygous loss-of-function mutations in MYLK are associated with aortic dissections.

Exome sequencing identifies SMAD3 mutations as a cause of familial thoracic aortic aneurysm and dissection with intracranial and other arterial aneurysms.

RATIONALE: Thoracic aortic aneurysms leading to acute aortic dissections (TAAD) can be inherited in families in an autosomal dominant manner. As part of the spectrum of clinical heterogeneity of familial TAAD, we recently described families with multiple members that had TAAD and intracranial aneurysms or TAAD and intracranial and abdominal aortic aneurysms inherited in an autosomal dominant manner. OBJECTIVE: To identify the causative mutation in a large family with autosomal dominant inheritance of TAAD with intracranial and abdominal aortic aneurysms by performing exome sequencing of 2 distantly related individuals with TAAD and identifying shared rare variants. METHODS AND RESULTS: A novel frame shift mutation, p. N218fs (c.652delA), was identified in the SMAD3 gene and segregated with the vascular diseases in this family with a logarithm of odds score of 2.52. Sequencing of 181 probands with familial TAAD identified 3 additional SMAD3 mutations in 4 families, p.R279K (c.836G>A), p.E239K (c.715G>A), and p.A112V (c.235C>T), resulting in a combined logarithm of odds score of 5.21. These 4 mutations were notably absent in 2300 control exomes. SMAD3 mutations were recently described in patients with aneurysms osteoarthritis syndrome and some of the features of this syndrome were identified in individuals in our cohort, but these features were notably absent in many SMAD3 mutation carriers. CONCLUSIONS: SMAD3 mutations are responsible for 2% of familial TAAD. Mutations are found in families with TAAD alone, along with families with TAAD, intracranial aneurysms, abdominal aortic and bilateral iliac aneurysms segregating in an autosomal dominant manner.

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.

Distress and psychosocial needs of a heterogeneous high risk familial cancer population.

In order to assess the levels of distress and psychosocial support needs of a high risk population, we undertook a study to look at both the objective and subjective levels of distress and the wants and needs of individuals from a high familial cancer risk population. Three hundred and eighteen individuals (160 affected, 158 unaffected) completed several distress and psychosocial needs questionnaires (including the Brief Symptom Inventory-18). Sixty key informants were also surveyed about their perspective on the support needs of this population. In the largely female (90%), largely HBOC syndrome group (approximately 90%), 20% had significant levels of generalized distress, with no significant differences between affected and unaffected individuals. Generalized distress was also not significantly different as a function of mutation status. Individuals who received inconclusive test results, however, were more likely to indicate somatic symptoms of distress. Those individuals who did not have social support were more likely to be those who had never had cancer and who either had a mutation, received inconclusive test results, or were not tested. Key informants were most likely to indicate that patients need more support. These results provide evidence for the importance of establishing regular psychosocial distress screening, including a focus on somatic symptoms, in such high risk populations.

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.

Maintenance of improved lipid levels following attendance at a cardiovascular risk reduction clinic: a 10-year experience.

BACKGROUND: Specialty cardiovascular risk reduction clinics (CRRC) increase the proportion of patients attaining recommended lipid targets; however, it is not known if the benefits are sustained after discharge. We evaluated the impact of a CRRC on lipid levels and assessed the long-term effect of a CRRC in maintaining improved lipid levels following discharge. METHODS: The medical records of consecutive dyslipidemic patients discharged > 6 months from a tertiary hospital CRRC from January 1991 to January 2001 were retrospectively reviewed. The primary outcome was the change in patients' lipid levels between the final CRRC visit and the most recent primary care follow-up. A worst-case analysis was conducted to evaluate the potential impact of the patients in whom the follow-up lipid profiles post-discharge from the CRRC were not obtained. RESULTS: Within the CRRC (median follow-up = 1.28 years in 1064 patients), we observed statistically significant improvements in all lipid parameters. In the 411 patients for whom post-discharge lipid profiles were available (median follow-up = 2.41 years), there were no significant differences observed in low-density lipoprotein-cholesterol, total cholesterol (TC), or triglycerides since CRRC discharge; however, there were small improvements in high-density lipoprotein-cholesterol (HDL-C) and TC:HDL ratio (p < 0.05 for both). The unadjusted worst-case analysis (653 patients with no follow-up lipid profiles) demonstrated statistically significant worsening of all lipid parameters between CRRC discharge and the most recent follow-up. However, when the change in lipid parameters between the baseline and the most recent follow-up was assessed in this analysis, the changes in all lipid parameters were significantly improved (p < 0.05). CONCLUSIONS: This study demonstrates that a CRRC can improve lipid levels and suggests that these benefits are sustained once patients are returned to the care of their primary physician.

Spontaneous and therapeutic abortions and the risk of breast cancer among BRCA mutation carriers.

INTRODUCTION: BRCA1 and BRCA2 mutation carriers are at increased risk for developing both breast and ovarian cancer. It has been suggested that carriers of BRCA1/2 mutations may also be at increased risk of having recurrent (three or more) miscarriages. Several reproductive factors have been shown to influence the risk of breast cancer in mutation carriers, but the effects of spontaneous and therapeutic abortions on the risk of hereditary breast cancer risk have not been well studied to date. METHODS: In a matched case-control study, the frequencies of spontaneous abortions were compared among 1,878 BRCA1 mutation carriers, 950 BRCA2 mutation carriers and 657 related non-carrier controls. The rates of spontaneous and therapeutic abortions were compared for carriers with and without breast cancer. RESULTS: There was no difference in the rate of spontaneous abortions between carriers of BRCA1 or BRCA2 mutations and non-carriers. The number of spontaneous abortions was not associated with breast cancer risk among BRCA1 or BRCA2 mutation carriers. However, BRCA2 carriers who had two or more therapeutic abortions faced a 64% decrease in the risk of breast cancer (odds ratio = 0.36; 95% confidence interval 0.16-0.83; p = 0.02). CONCLUSION: Carrying a BRCA1 or BRCA2 mutation is not a risk factor for spontaneous abortions and spontaneous abortions do not appear to influence the risk of breast cancer in carriers of BRCA1 or BRCA2 mutations. However, having two or more therapeutic abortions may be associated with a lowered risk of breast cancer among BRCA2 carriers.

The clinical effect and tolerability of ezetimibe in high-risk patients managed in a specialty cardiovascular risk reduction clinic.

INTRODUCTION: Ezetimibe (EZ) is a selective cholesterol absorption inhibitor approved for use in Canada. The effect and tolerability of EZ among patients was evaluated in the clinical setting of a specialty cardiovascular risk reduction clinic at the University of Alberta Hospital, Edmonton, Alberta. patients and METHODS: All patients 18 years of age or older who were prescribed EZ were included, unless they failed to take EZ for a minimum of two weeks, did not have baseline and on-EZ low-density lipoprotein cholesterol (LDL-C) levels, or had concomitant lipid-lowering drugs or dosages changed within one month of starting EZ. RESULTS: Eighty-four patients (mean age 57.9 years) were included. By Framingham risk calculation, 71.4% were found to be high-risk patients, 13.1% moderate-risk patients and 15.5% low-risk patients; 66.7% of patients had prior cardiovascular events. On EZ, the mean reductions were: total cholesterol level 1.11 mmol/L (16.5%); LDL-C level 1.01 mmol/L (22.3%); high-density lipoprotein cholesterol level 0.06 mmol/L (4.6%); and ratio of total cholesterol level to high-density lipoprotein cholesterol level 0.68 mmol/L (12.8%); all were statistically significant (P<0.001). Results were similar when stratified by primary (n=28) versus secondary (n=56) prevention. Patients on EZ monotherapy (n=34) had mean LDL-C reductions of 1.03 mmol/L (20.5%) compared with 1.19 mmol/L (30.1%) or 0.95 mmol/L (22.5%), where EZ was added to low-dose or high-dose statins (P<0.01 for all). On EZ, 30 patients (35.7%) achieved previously unattainable target LDL-C levels. Four patients discontinued the drug due to side effects. CONCLUSIONS: EZ is safe and effective in high-risk patients treated in the clinical setting of a cardiovascular risk reduction clinic. A mean LDL-C reduction of 1 mmol/L (20% to 30%) in all patient subgroups is consistent with previous clinical trial results. The significant reduction in LDL-C (mean 22.5%) observed in the EZ plus high-dose statin subgroup provides clinical evidence for use of this medication beyond published studies.

Risk factors for endometrial cancer among women with a BRCA1 or BRCA2 mutation: a case control study.

BRCA mutation carriers may use tamoxifen for breast cancer prevention or treatment. Hormone replacement therapy is often prescribed after surgical menopause and oral contraceptives are recommended for ovarian cancer prevention. The objective of this study was to assess the impact of these medications and other risk factors on endometrial cancer risk in BRCA carriers. Women with a BRCA1 or BRCA2 mutation were identified from a registry of mutation carriers. Cases were 83 women who had a diagnosis of endometrial cancer. Controls were 1027 matched women who did not develop endometrial cancer and who had an intact uterus. All women completed a baseline questionnaire, which included questions about ages at menarche and menopause, oral contraceptive use, hormone replacement therapy use, hysterectomy, oophorectomy, breast cancer history and tamoxifen use. We estimated the odds ratio associated with each risk factor in a multivariate analysis. No differences were found between cases and controls in terms of age at menarche, BMI, smoking, or oral contraceptive use. In a multivariate analysis, for women taking estrogen-only hormone replacement therapy, the odds ratio was 0.23 (95% CI 0.03-1.78, p = 0.16), and for women taking progesterone-only hormone replacement therapy the odds ratio was 6.91 (95% CI 0.99-98.1, p = 0.05). The adjusted odds ratio for endometrial cancer associated with a history of tamoxifen use was 3.50 (95% CI 1.51-8.10, p = 0.003). The observed increased risk of endometrial cancer associated with progesterone-only therapy merits further study.

The hereditary spectrum of pancreatic cancer: the Edmonton experience.

OBJECTIVE: Pancreatic cancer is known to aggregate in some families and has been associated with a wide variety of cancer syndromes. The authors describe their experience with pancreatic cancer and the range of associated cancer syndromes. METHODS: The charts of all patients seen for concern of a hereditary cancer syndrome in the Cancer Genetics Clinic at the University of Alberta between 1995 and 2002 were reviewed. RESULTS: Forty families reported a personal or family history of pancreatic cancer in the context of a possible hereditary cancer syndrome. Three additional families reported a history of pancreatitis. Twenty-four (56%) of those families were suspected of having a hereditary breast and ovarian cancer syndrome. A further seven (16%) were suspected of having hereditary nonpolyposis colon cancer. Only three (7%) were believed to be at risk for a site-specific pancreatic cancer syndrome. Another three (7%) were suspicious for hereditary pancreatitis. The remaining family histories were suggestive of Li-Fraumeni syndrome, von Hippel-Lindau syndrome or a nonspecific cancer predisposition. CONCLUSIONS: With such a wide variety of hereditary cancer syndromes associated with pancreatic cancer, an accurate assessment of the family history is essential to determine the most appropriate cancer screening for at-risk family members and to guide any molecular testing that may be offered.

From gold-medal glory to prohibition: the early evolution of cocaine in the United Kingdom and the United States.

As reported in the 2011 World Drug Report, cocaine is likely to be the most problematic drug worldwide in terms of trafficking-related violence and second only to heroin in terms of negative health consequences and drug deaths. Over a period of 60 years, cocaine evolved from the celebrated panacea of the 1860s to outlawed street drug of the 1920s. As demonstrated by the evolution of cocaine use and abuse in the United Kingdom and United States during this time period, cultural attitudes influenced both the acceptance of cocaine into the medical field and the reaction to the harmful effects of cocaine. Our review of articles on cocaine use in the United Kingdom and the United States from 1860 to 1920 reveals an attitude of caution in the United Kingdom compared with an attitude of progressivism in the United States. When the trends in medical literature are viewed in the context of the development of drug regulations, our analysis provides insight into the relationship between cultural attitudes and drug policy, supporting the premise that it is cultural and social factors which shape drug policy, rather than drug regulations changing culture.

Epithelioid malignant peripheral nerve sheath tumor arising in a schwannoma, in a patient with "neuroblastoma-like" schwannomatosis and a novel germline SMARCB1 mutation.

Epithelioid malignant peripheral nerve sheath tumors arising in preexisting schwannomas are extremely rare. We report an unusual example occurring in a patient with multiple schwannomas (schwannomatosis), all but 1 of which showed "neuroblastoma-like" histology. By immunohistochemistry, both the epithelioid malignant peripheral nerve sheath tumor and the schwannomas showed a complete loss of the Smarcb1 protein. Subsequent genetic evaluation revealed the presence of a novel germline mutation in the SMARCB1/INI1 gene in the patient and in 3 of her children, 2 of whom were diagnosed with atypical teratoid/rhabdoid tumors of the brain.

Oophorectomy after menopause and the risk of breast cancer in BRCA1 and BRCA2 mutation carriers.

BACKGROUND: To evaluate the effect of the cumulative number of ovulatory cycles and its contributing components on the risk of breast cancer among BRCA mutation carriers. METHODS: We conducted a matched case-control study on 2,854 pairs of women with a BRCA1 or BRCA2 mutation. Conditional logistic regression was used to estimate the association between the number of ovulatory cycles and various exposures and the risk of breast cancer. Information from a subset of these women enrolled in a prospective cohort study was used to calculate age-specific breast cancer rates. RESULTS: The annual risk of breast cancer decreased with the number of ovulatory cycles experienced (ρ = -0.69; P = 0.03). Age at menarche and duration of breastfeeding were inversely related with risk of breast cancer among BRCA1 (P(trend) < 0.0001) but not among BRCA2 (P(trend) ≥ 0.28) mutation carriers. The reduction in breast cancer risk associated with surgical menopause [OR, 0.52; 95% confidence interval (CI), 0.40-0.66; P(trend) < 0.0001] was greater than that associated with natural menopause (OR, 0.81; 95% CI, 0.62-1.07; P(trend) = 0.14). There was a highly significant reduction in breast cancer risk among women who had an oophorectomy after natural menopause (OR, 0.13; 95% CI, 0.02-0.54; P = 0.006). CONCLUSIONS: These data challenge the hypothesis that breast cancer risk can be predicted by the lifetime number of ovulatory cycles in women with a BRCA mutation. Both pre- and postmenopausal oophorectomy protect against breast cancer. IMPACT: Understanding the basis for the protective effect of oophorectomy has important implications for chemoprevention.

Variation in rates of uptake of preventive options by Canadian women carrying the BRCA1 or BRCA2 genetic mutation.

BACKGROUND: Women with a BRCA1 or BRCA2 genetic mutation have several options for cancer prevention, including prophylactic surgery, chemoprevention and screening. In this study we report on preventive practices used by women with and without breast cancer and examine differences in their selection of preventive practices according to geographic area in Canada. METHODS: Canadian women with a BRCA1 or BRCA2 mutation were followed after genetic testing and questioned about their preventive practices. Women reported on uptake of prophylactic mastectomy, prophylactic oophorectomy, tamoxifen or raloxifene usage and screening practices. We analyzed the uptake of each preventive option and completed a subanalysis according to the geographic area in Canada where genetic testing was provided. RESULTS: The study included 672 women. Follow-up questionnaires were completed after a mean of 4.0 years (range 1.6-9.1 years). Of the 342 women without breast cancer, 72 (21%) had had a prophylactic bilateral mastectomy. Three hundred and sixty-three women (54%) had had a bilateral prophylactic oophorectomy. Seventeen (6%) of the 270 women without breast cancer who had not had a prophylactic mastectomy took tamoxifen, and 12 (4%) reported taking raloxifene. Of the 342 women without breast cancer, 157 (46%) had not undertaken any cancer prevention option (mastectomy, oophorectomy or treatment with tamoxifen or raloxifene). Sixty-five (39%) of the 167 women from Ontario, 19 (34%) of the 56 women from Western Canada and 73 (62%) of the 119 women from Quebec had not undertaken any preventive procedure. CONCLUSION: Significant differences in the uptake of preventive options by women with a BRCA1 or BRCA2 mutation were observed across 3 regions of Canada. Future research is needed to explain why these differences exist.

Age at menarche and the risk of breast cancer in BRCA1 and BRCA2 mutation carriers.

Age at menarche is a strong and consistent predictor of breast cancer risk in the general population, but has not been well studied in women with a family history of breast cancer. We conducted this study to examine whether the presence of a deleterious BRCA1 or BRCA2 mutation influences age at menarche and to investigate whether or not there is an association between age at menarche and the risk of breast cancer in BRCA1 or BRCA2 mutation carriers. The presence of a deleterious BRCA1 or BRCA2 mutation did not appear to influence a woman's age at menarche. A matched case-control study was conducted on 1311 pairs of women who have been identified to be carriers of a deleterious mutation in either the BRCA1 (n = 945 pairs) or the BRCA2 gene (n = 366 pairs). Information about age at menarche was derived from a questionnaire routinely administered to carriers of a mutation in either gene. Among women who carried a deleterious BRCA1 mutation, age at menarche was inversely associated with the risk of breast cancer (p trend = 0.0002). This association was not observed among BRCA2 mutation carriers (p trend = 0.49). Compared with BRCA1 carriers whose age at menarche was < or =11 years, women with a menarcheal age between 14 and 15 years old had a 54% reduction in risk (OR = 0.46; 95% CI 0.30-0.69). This study implicates early age at menarche as a determinant of breast cancer among women with a BRCA1 mutation.

Medical genetics: 3. An approach to the adult with a genetic disorder.

Many genetic disorders do not manifest themselves until the adult years. Such disorders often involve multiple genetic factors interacting with multiple environmental factors, over time, to produce a phenotype. This paper reviews the modes of inheritance of genetic disorders and describes the types of genetic testing that are currently available. It offers clues that should lead physicians to suspect that an adult patient might have a genetic disorder and raises issues that should be considered in counselling the patient about genetic testing. Resources for patients and their family physicians are also discussed.