Countercurrents: The bias of choice

Of the several kinds of bias that might corrupt an epidemiology study, selection bias is the most insidious […]

Countercurrents: Is now the right time to pull the plug on mammography?

In their report of 10 December 2018, the Canadian Task Force on Preventive Health Care gave a lukewarm endorsement of screening mammography.[...]

Abstract P1-09-03: Withdrawn

This abstract was withdrawn by the authors.

Citation Format: Kotsopoulos J, Zaman T, Lubinski J, Sun P, Salmena L, Narod SA. Withdrawn [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P1-09-03.

The risk of breast cancer in BRCA1 and BRCA2 mutation carriers without a first-degree relative with breast cancer

The objective of this study was to estimate the lifetime risk of breast cancer in women with a BRCA1 or BRCA2 mutation with and without at least 1 first-degree relative with breast cancer. A total of 2835 women with a BRCA1 or BRCA2 mutation were followed. Age- and gene-specific breast cancer rates were calculated. The relative risks of breast cancer for subjects with a family history of breast cancer, compared to no family history were calculated. The mean age at baseline was 41.1 years, and they were followed for a mean of 6.0 years. The estimated penetrance of breast cancer to age 80 years was 60.8% for BRCA1 and 63.1% for BRCA2. For all BRCA carriers, the penetrance of breast cancer to age 80 for those with no first-degree relative with breast cancer was 60.4% and 63.3% for those with at least 1 first-degree relative with breast cancer. The risk of breast cancer for BRCA carriers with no first-degree relative with breast cancer is substantial, and as a result, clinical management for these women should be the same as those for women with an affected relative.

Coming of age in Canada: a study of population-based genetic testing for breast and ovarian cancer

The BRCA1 and BRCA2 genes are the two most commonly mutated in hereditary breast and ovarian cancer, and they are the canonical pair when it comes to cancer testing. [...]

Serum selenium levels predict survival after breast cancer

BACKGROUND

Studies have reported an inverse relationship between serum selenium levels and cancer incidence, but the impact of low serum selenium status on survival after a diagnosis of breast cancer has not been established.

METHODS

We obtained a blood sample from 546 women diagnosed with a first primary invasive breast cancer between 2008 and 2015 in the region of Szczecin, Poland. Blood was collected after diagnosis, but prior to treatment. Serum selenium was quantified by mass spectroscopy and each patient was assigned to one of four categories (quartiles) based on the distribution in the entire cohort. Patients were followed from diagnosis to death over a mean follow-up of 3.8 years. Vital status was obtained by linkage to the Polish National Death Registry.

RESULTS

The 5-year overall actuarial survival was 68.1% for women in the lowest (< 64.4 µg/L) and 82.5% for those in the highest (> 81.0 µg/L) quartile of serum selenium. In an adjusted analysis, the hazard ratio for death was 2.49 (95%CI 1.53-4.04; P = 0.0002) for patients in the lowest quartile of serum selenium, compared to those in all other quartiles. The effect of low selenium on breast cancer-specific mortality was stronger for women who were past smokers (HR 6.03; 95%CI 1.96-18.6; P = 0.0002).

CONCLUSIONS

This study suggests that a selenium level in excess of 64.4 µg//L might be beneficial for women undergoing treatment for breast cancer and that selenium supplementation to achieve this level may favorably impact the outcome. Further studies are needed to confirm this association and to evaluate the impact of selenium supplementation on breast cancer survival among women with low post-diagnostic selenium levels.

Women with cancer in low-income countries

In the 1 November issue of The Lancet in 2016, three papers and three accompanying editorials reviewed the descriptive epidemiology of breast and cervical cancer in low-income countries, highlighting the shortcomings of current efforts at cancer control and the need for improvement [...]

Does adjuvant radiation therapy benefit women with small mammography-detected breast cancers?

BACKGROUND

Women with small nonpalpable breast tumours have an excellent prognosis. The benefit of radiotherapy in this group of low-risk women is unknown.

METHODS

A cohort of 1595 women with stages i-iii invasive breast cancer treated with breast-conserving surgery were followed for local recurrence. Using t-tests, baseline demographic data and tumour characteristics were compared for the women who had palpable (n = 1023) and mammography-detected (n = 572) breast cancers. The 15-year actuarial risk of local recurrence was estimated using a Kaplan-Meier method, stratified for adjuvant radiation therapy (yes or no), tumour palpability (palpable or not), and tumour size (≤1 cm or >1 cm). Hazard ratios (hrs) and 95% confidence intervals (95% cis) were calculated using a multivariate Cox regression model. Results were considered statistically significant if 2-tailed p values were less than 0.05.

RESULTS

Among women with a nonpalpable tumour, the 15-year actuarial rates of local recurrence were, respectively, 13.9% and 18.3% for those treated and not treated with adjuvant radiation therapy (hr: 0.65; 95%ci: 0.40 to 1.06; p = 0.08). Among women with small nonpalpable breast cancers (≤1.0 cm), the rates were 14.6% and 13.4% respectively (p = 0.67). The absolute reduction in 15-year local recurrence was 11.0% for women with palpable tumours.

CONCLUSIONS

Our results suggest that women with small (<1 cm) screen-detected nonpalpable breast cancers likely derive little benefit from adjuvant radiotherapy; however, an adequately powered randomized trial would be required to make definitive conclusions.

Do acronyms belong in the medical literature?: A Countercurrents Series

After controlling for ds, rd, an interaction term for ds/cs, [...]

Genetic testing for BRCA1 and BRCA2 in the Province of Ontario

In 2001, genetic testing for BRCA1 and BRCA2 was introduced in Ontario, for women at high-risk of breast or ovarian cancer. To date over 30,000 individuals have been tested throughout Ontario. Testing was offered to all Ontario residents who were eligible under any of 13 criteria. We report the results of tests conducted at Mount Sinai Hospital from 2007 to 2014. A total of 4726 individuals were tested, 764 (16.2%) were found to carry a pathogenic variant (mutation). Among 3684 women and men who underwent testing without a known familial BRCA mutation, 331 (9.0%) were found to carry a mutation. Among 1042 women and men tested for a known family mutation, 433 (41.6%) were positive. There were 603 female mutation carriers, of these, 303 were affected with breast or ovarian cancer (50%) and 16 with another cancer (2.3%). Of 284 unaffected female carriers, 242 (85%) were tested for a known family mutation and 42 (15%) were the first person in the family to be tested. By placing greater emphasis on recruiting unaffected female relatives of known mutation carriers for testing, greater than one-half of newly identified carriers will be unaffected.

Is it time to offer BRCA1 and BRCA2 testing to all Jewish women?

It was 2007 when Women’s College Hospital first began to test for BRCA1 and BRCA2 mutations among all Jewish women in Ontario [...]

Counterpoint re: "Mammography screening-sticking to the science"

In the Canadian National Breast Screening Study, the hazard ratio for breast cancer–specific death was 1.47 for women with cancers detected in the prevalence screening round, 0.9 for women with cancers detected in the subsequent four screening rounds, and 1.05 for women with cancers detected in all screening rounds [...]

Have we given up on a cure for ovarian cancer?

In December 2014, on the force Web site, executive director Sue Friedman, heralded a game-changing holiday gift for people with BRCA mutations: “Today is a landmark for the hboc [hereditary breast and ovarian cancer] community” [...]

Prevalence of founder mutations in the BRCA1 and BRCA2 genes among unaffected women from the Bahamas

Population-based testing for BRCA1/2 mutations detects a high proportion of carriers not identified by cancer family history-based testing. We sought to determine whether population-based testing is an effective approach to genetic testing in the Bahamas, where 23% of women with breast cancer carry one of seven founder mutations in the BRCA1 or BRCA2 gene. We determined the prevalence of founder BRCA mutations in 1847 Bahamian women without a personal history of breast or ovarian cancer, unselected for age or family history. We found that 2.8% (20/705) of unaffected women with a family history of breast/ovarian cancer and 0.09% (1/1089) of unaffected women without a family history carry a BRCA mutation. A total of 38% of unaffected women with a known mutation in the family were found to carry the familial mutation. We previously suggested that all Bahamian women with breast or ovarian cancer be offered genetic testing. These current data suggest that additionally all unaffected Bahamian women with a family history of breast/ovarian cancer should be offered genetic testing for the founder BRCA mutations.

The risk of contralateral breast cancer in daughters of women with and without breast cancer

We aimed to estimate the 15-year and lifetime risks of contralateral breast cancer in breast cancer patients according to the age of diagnosis of the first cancer and the history of breast cancer in the mother. The risks of contralateral breast cancer were estimated for all 78,775 breast cancer patients in the Swedish Family-Cancer Database (age at diagnosis of first breast cancer <70 years). The risk of experiencing a contralateral breast cancer within 15 years of diagnosis was 8.4% [95% confidence interval (CI): 8.1-8.7%] for women with an unaffected mother, was 12% (95%CI: 11-13%) for a woman with a mother with unilateral breast cancer and was 13% (95%CI: 9.5-17%) for women with a mother with bilateral breast cancer. In early-onset diagnosed women (<50 years) with an unaffected mother, the risk of contralateral breast cancer until age 80 was 23% (95%CI: 20-26%) and for late-onset (50-69 years) diagnosed women it was 17% (95%CI: 14-21%). In a woman with a mother with an early-onset unilateral breast cancer, risk of contralateral breast cancer by age 80 was 35% (95%CI: 25-46%). Women with a mother with early-onset bilateral breast cancer had 31% (95%CI: 12-67%) lifetime risk of contralateral breast cancer. The risk of contralateral breast cancer is higher for daughters of breast cancer patients than for daughters of women without breast cancer. Maternal cancer history and age at onset of first breast cancer in women should be taken into account when counseling breast cancer patients about their risk of contralateral breast cancer.

Factors associated with genetic counseling and BRCA testing in a population-based sample of young Black women with breast cancer

Concerns about the potential for genomic advances to increase health disparities have been raised. Thus, it is important to assess referral and uptake of genetic counseling (GC) and testing in minority populations at high risk for hereditary breast and ovarian cancer (HBOC). Black women diagnosed with invasive breast cancer ≤age 50 in 2009-2012 were recruited through the Florida State Cancer Registry 6-18 months following diagnosis and completed a baseline questionnaire. Summary statistics, Chi-square tests, and path modeling were conducted to examine which demographic and clinical variables were associated with referral and access to genetic services. Of the 440 participants, all met national criteria for GC, yet only 224 (51 %) were referred for or received GC and/or HBOC testing. Variables most strongly associated with healthcare provider referral for GC included having a college education (OR 2.1), diagnosis at or below age 45 (OR 2.0), and triple negative tumor receptor status (OR 1.7). The strongest association with receipt of GC and/or HBOC testing was healthcare provider referral (OR 7.9), followed by private health insurance at diagnosis (OR 2.8), and household income greater than $35,000 in the year prior to diagnosis (OR 2.0). Study findings suggest efforts are needed to improve genetic services access among a population-based sample of high-risk Black women. These results indicate that socioeconomic factors and physician referral patterns contribute to disparities in access to genetic services within this underserved minority population.

Complications following surgery with or without radiotherapy or radiotherapy alone for prostate cancer

BACKGROUND

Men undergoing treatment of clinically localised prostate cancer may experience a number of treatment-related complications, which affect their quality of life.

METHODS

On the basis of population-based retrospective cohort of men undergoing surgery, with or without subsequent radiotherapy, or radiotherapy alone for prostate cancer in Ontario, Canada, we measured the incidence of treatment-related complications using administrative and billing data.

RESULTS

Of 36 984 patients, 15 870 (42.9%) underwent surgery alone, 4519 (12.2%) underwent surgery followed by radiotherapy, and 16 595 (44.9%) underwent radiotherapy alone. For all end points except urologic procedures, the 5-year cumulative incidence rates were lowest in the surgery only group and highest in the radiotherapy only group. Intermediary rates were seen in the surgery followed by radiotherapy group, except for urologic procedures where rates were the highest in this group. Although age and comorbidity were important predictors, radiotherapy as the primary treatment modality was associated with higher rates for all complications (adjusted hazard ratios 1.6-4.7, P=0.002 to <0.0001).

CONCLUSIONS

In patients treated for prostate cancer, radiation after surgery increases the rate of complications compared with surgery alone, though these rates remain lower than patients treated with radiation alone. This information may inform patient and physician decision making in the treatment of prostate cancer.

The prevalence of BRCA1 and BRCA2 mutations among young Mexican women with triple-negative breast cancer

Various guidelines recommend that women with triple-negative breast cancer should be tested for BRCA1 mutations, but the prevalence of mutations may vary with ethnic group and with geographic region, and the optimal cutoff age for testing has not been established. We estimated the frequencies of BRCA1 and BRCA2 (BRCA) mutations among 190 women with triple-negative breast cancer, unselected for family history, diagnosed at age 50 or less at a single hospital in Mexico City. Patients were screened for 115 recurrent BRCA mutations, which have been reported previously in women of Hispanic origin, including a common large rearrangement Mexican founder mutation (BRCA1 ex9-12del). A BRCA mutation was detected in 44 of 190 patients with triple-negative breast cancer (23 %). Forty-three mutations were found in BRCA1 and one mutation was found in BRCA2. Seven different mutations accounted for 39 patients (89 % of the total mutations). The Mexican founder mutation (BRCA1 ex9-12del) was found 18 times and accounted for 41 % of all mutations detected. There is a high prevalence of BRCA1 mutations among young triple-negative breast cancer patients in Mexico. Women with triple-negative breast cancer in Mexico should be screened for mutations in BRCA1.

Overdiagnosis in breast cancer chemoprevention trials

Several randomized controlled trials have demonstrated that the preventive use of an antiestrogen agent such as tamoxifen, raloxifene, anastrozole, or exemestane will reduce the incidence of estrogen receptor (er)–positive breast cancers by 50% or more. The reduction in risk becomes apparent shortly after tamoxifen initiation. However, no mortality benefit has yet been demonstrated with tamoxifen or any other agent, an effect that might be statistical: that is, the statistical power to detect a difference in mortality could be lacking because deaths from breast cancer are far fewer in number than cases of breast cancer, and because the average time to cancer is much shorter than the time to death. In other words, it could be too early to see an effect. However, the lack of an observed survival benefit might also be a result of chemoprevention agents preferentially preventing cancers that would rarely lead to death. That paradigm extends the (controversial) concepts of overdiagnosis and of the potential for spontaneous regression of some lowgrade breast cancers [...]

Prognostic value of INPP4B protein immunohistochemistry in ovarian cancer

PURPOSE OF INVESTIGATION

Ovarian cancer is associated with poor prognosis and altered protein expression patterns may be useful for identifying patients likely to have poor disease outcomes. The impact of altered INPP4B protein expression on prognosis is unclear. The aim of this study was to evaluate the implication of INPP4B expression changes in a large series of ovarian cancer tissue samples.

MATERIALS AND METHODS

Tissue microarrays were constructed from 599 epithelial ovarian tumors and stained with antibodies for INPP4B, p53, and PTEN. Proportional hazard models were used to estimate survival hazard ratios (HRs) associated with altered protein expression.

RESULTS

Seventy-nine percent of the ovarian cancers demonstrated loss of INPP4B, whereas 53% showed aberrant p53 expression (i.e., complete loss of p53 or over-expression of p53) and 8% showed loss of PTEN. INPP4B was frequently lost in serous and endometrioid cancer subtypes, aberrant p53 expression was most common among serous subtype, and loss of PTEN was most common among endometrioid tumors (p for all three proteins across histologic subtypes ≤ 0.0001). INPP4B loss or aberrant p53 expression were both associated with increased mortality (HR = 1.84; 95% CI 1.27 - 2.68 and HR = 3.10; 95% CI 2.33 - 4.11, respectively); however, in multivariate models, only the relationship with p53 achieved statistical significance (HR = 1.20; 95% CI 0.82 - 1.76 for INPP4B and HR = 1.73; 95% CI 1.28 - 2.34 for p53). Conclusion: The INPP4B protein is frequently lost in serous and endometrioid subtypes of ovarian cancer. A possible prognostic role of INPP4B for endometrioid ovarian tumors requires further evaluation.

Survival in women with ovarian cancer with and without microsatellite instability

PURPOSE OF INVESTIGATION

Microsatellite instability (MSI) is a hallmark of defective mismatch repair and is present in approximately 20% of ovarian cancers. It is not known if the presence of MSI predicts survival in women with epithelial ovarian cancer.

MATERIALS AND METHODS

Cases of epithelial ovarian cancer were ascertained from a population-based study in Ontario and tumour samples were tested for MSI, using five MSI markers. Patients were divided into MSI-high and MSI-low/normal, according to National Cancer Institute criteria. The authors compared the prevalence of specific prognostic factors in the two subgroups, including age, grade, stage, and histology. They estimated the hazard ratio for death from ovarian cancer associated with MSI-high and with other prognostic factors using a multi-variate analysis.

RESULTS

A total of 418 ovarian cancer patients were included. One hundred and twenty-seven (19.7%) cancers were MSI- high. Subgroup analyses did not reveal any statistically significant differences for pathologic features associated with MSI status. No survival difference was seen according to MSI status.

CONCLUSIONS

The presence of MSI in ovarian cancer is not associated with survival.

Erratum: Salpingectomy to prevent ovarian cancer

[This corrects the article on p. 145 in vol. 20, PMID: 23737681.].

Prevalence of BRCA1 and BRCA2 mutations in unselected breast cancer patients from Peru

The prevalence of BRCA1 and BRCA2 mutations among breast cancer patients in Peru has not yet been explored. We enrolled 266 women with breast cancer from a National cancer hospital in Lima, Peru, unselected for age or family history. DNA was screened with a panel of 114 recurrent Hispanic BRCA mutations (HISPANEL). Among the 266 cases, 13 deleterious mutations were identified (11 in BRCA1 and 2 in BRCA2), representing 5% of the total. The average age of breast cancer in the mutation-positive cases was 44 years. BRCA1 185delAG represented 7 of 11 mutations in BRCA1. Other mutations detected in BRCA1 included: two 2080delA, one 943ins10, and one 3878delTA. The BRCA2 3036del4 mutation was seen in two patients. Given the relatively low cost of the HISPANEL test, one should consider offering this test to all Peruvian women with breast or ovarian cancer.

Impact of screening mammography on mortality from breast cancer before age 60 in women 40 to 49 years of age

BACKGROUND

Whether screening mammography programs should include women in their 40s is controversial. In Canada, screening of women aged 40-49 years has not been shown to reduce mortality from breast cancer. Given that screening mammography reduces mean tumour size and that tumour size is inversely associated with survival, the lack of benefit seen with screening is puzzling and suggests a possible adverse effect on mortality of mammography or subsequent treatment (or both) that counterbalances the expected benefit derived from downstaging.

METHODS

We followed 50,436 women 40-49 years of age until age 60 for mortality from breast cancer. Of those women, one half had been randomly assigned to annual mammography and one half to no mammography. The impact of mammography on breast cancer mortality was estimated using a left-censored Cox proportional hazards model.

RESULTS

Of 256 deaths from breast cancer recorded in the study cohort, 134 occurred in women allocated to mammography, and 122 occurred in those receiving usual care and not allocated to mammography. The cumulative risk of death from breast cancer to age 60 was 0.53% for women assigned to mammography and 0.48% for women not so assigned. The hazard ratio for breast cancer-specific death associated with 1 or more screening mammograms before age 50 was 1.10 (95% confidence interval: 0.86 to 1.40).

CONCLUSIONS

Mammography in women 40-49 years of age is associated with a small but nonsignificant increase in the risk of dying of breast cancer before age 60. Caution should be exercised when recommending mammographic screening to women before age 50.

Strategies for recruitment of relatives of BRCA mutation carriers to a genetic testing program in the Bahamas

The prevalence of BRCA1 and BRCA2 mutations among unselected breast cancer patients in the Bahamas is 23%. It is beneficial to advise relatives of mutation carriers that they are candidates for genetic testing. Women who test positive are then eligible for preventive interventions, such as oophorectomy. It is not clear how often relatives of women with a mutation in the Bahamas wish to undergo genetic testing for the family mutation. Furthermore, it is not clear how best to communicate this sensitive information to relatives in order to maximize patient compliance. We offered genetic testing to 202 first-degree relatives of 58 mutation carriers. Of 159 women who were contacted by the proband or other family member, only 14 made an appointment for genetic testing (9%). In contrast, among 32 relatives who were contacted directly by the genetic counselor, 27 came for an appointment (84%). This study suggests that for recruitment of relatives in the Bahamas, direct contact by counselor is preferable to using the proband as an intermediary.

The impact of a BRCA2 mutation on mortality from screen-detected prostate cancer

Background:

Men with a BRCA2 mutation face an increased risk of prostate cancer. These cancers tend to have an aggressive nature and it has not yet been demonstrated that regular screening of BRCA2 carriers is associated with improved survival.

Methods:

We identified 4187 men who underwent a prostate cancer biopsy for an elevated PSA or an abnormal digital rectal examination between 1998 and 2010. We screened the BRCA2 gene in its entirety for mutations and we followed the men for death from prostate cancer until December 2012.

Results:

The 12-year prostate cancer-specific survival rate was 94.3% for men without a BRCA2 mutation and was 61.8% for men with a mutation (P<10⁻⁴; log-rank test).

Conclusions:

The survival of men with screen-detected prostate cancer and a BRCA2 mutation is much poorer than expected.

A comparison of the risks of in-breast recurrence after a diagnosis of dcis or early invasive breast cancer

BACKGROUND

It is controversial whether ductal carcinoma in situ (dcis) is a preinvasive marker of breast cancer or if it is part of a spectrum of small cancers with malignant potential. Comparing clinical outcomes in women with invasive and noninvasive breast lesions might help to resolve the issue.

METHODS

From a database of 2641 patients with breast cancer, we selected women who had been treated with breast-conserving surgery for a cancer that was 2.0 cm or less in size, node-negative, and nonpalpable. No subject received chemotherapy. Cancers were categorized as noninvasive (stage 0, n = 172) or invasive (stage 1, n = 401) based on a review of the pathology records. We compared the actuarial risks of in-breast recurrence after invasive and noninvasive breast lesions before and after adjusting for tamoxifen and radiotherapy.

RESULTS

The 18-year cumulative risk of in-breast recurrence was 35.2% for patients with dcis and 12.8% for patients with small invasive cancers (hazard ratio: 2.4; 95% confidence interval: 1.5 to 3.8; p < 0.0003). After adjustment for radiotherapy and tamoxifen treatment, the difference was small and nonsignificant (hazard ratio: 1.4; 95% confidence interval: 0.9 to 2.4; p = 0.22).

CONCLUSIONS

For women with small, nonpalpable, node-negative breast cancers, the likelihood of experiencing an in-breast recurrence was associated with radiotherapy and with tamoxifen, but not with the presence of cancer cells invading beyond the basement membrane.

Factors associated with breast cancer mortality after local recurrence

PURPOSE

We aimed to identify risk factors for mortality after local recurrence in women treated for invasive breast cancer with breast-conserving surgery.

EXPERIMENTAL DESIGN

Our prospective cohort study included 267 women who were treated with breast-conserving surgery at Women's College Hospital from 1987 to 1997 and who later developed local recurrence. Clinical information and tumour receptor status were abstracted from medical records and pathology reports. Patients were followed from the date of local recurrence until death or last follow-up. Survival analysis used a Cox proportional hazards model.

RESULTS

Among the 267 women with a local recurrence, 97 (36.3%) died of breast cancer within 10 years (on average 2.6 years after the local recurrence). The actuarial risk of death was 46.1% at 10 years from recurrence. In a multivariable model, predictors of death included short time from diagnosis to recurrence [hazard ratio (hr) for <5 years compared with ≥10 years: 3.40; 95% confidence interval (ci): 1.04 to 11.1; p = 0.04], progesterone receptor positivity (hr: 0.35; 95% ci: 0.23 to 0.54; p < 0.001), lymph node positivity (hr: 2.1; 95% ci: 1.4 to 3.3; p = 0.001), and age at local recurrence (hr for age >45 compared with age ≤45 years: 0.61; 95% ci: 0.38 to 0.95; p = 0.03).

CONCLUSIONS

The risk of death after local recurrence varies widely. Risk factors for death after local recurrence include node positivity, progesterone receptor negativity, young age at recurrence, and short time from diagnosis to recurrence.

A prior diagnosis of breast cancer is a risk factor for breast cancer in BRCA1 and BRCA2 carriers

BACKGROUND

The risk of breast cancer in carriers of BRCA1 and BRCA2 mutations is influenced by factors other than the genetic mutation itself. Modifying factors include a woman's reproductive history and family history of cancer. Risk factors are more likely to be present in women with breast cancer than in women without breast cancer, and therefore the risk of cancer in the two breasts should not be independent. It is not clear to what extent modifying factors influence the risk of a first primary or a contralateral breast cancer in BRCA carriers.

METHODS

We conducted a matched case-control study of breast cancer among 3920 BRCA1 or BRCA2 mutation carriers. We asked whether a past history of breast cancer in the contralateral breast was a risk factor for breast cancer.

RESULTS

After adjustment for age, country of residence, and cancer treatment, a previous cancer of the right breast was found to be a significant risk factor for cancer of the left breast among BRCA1 or BRCA2 carriers (relative risk: 2.1; 95% confidence interval: 1.4 to 3.0; p < 0.0001).

CONCLUSIONS

In a woman with a BRCA1 or BRCA2 mutation who is diagnosed with breast cancer, the risk of cancer in the contralateral breast depends on the first diagnosis. That observation supports the hypothesis that there are important genetic or non-genetic modifiers of cancer risk in BRCA carriers. Discovering risk modifiers might lead to greater personalization of risk assessment and management recommendations for BRCA-positive patients.

Recurrent mutations of BRCA1 and BRCA2 in Poland: an update

Three founder alleles of BRCA1 (C61G, 4153delA, 5382insC) were reported in Poland in 2000, and these three mutations have comprised the standard testing panel used throughout the country. However, since 2000, other recurrent mutations of BRCA1 and BRCA2 have been reported. To establish if the inclusion of one or more of these mutations will increase the sensitivity of the standard test panel, we studied 1164 Polish women with unselected breast cancer diagnosed at age of 50 or below. All women were genotyped for 12 recurrent mutations of BRCA1 and BRCA2. We identified a mutation in 83 of 1164 patients (7.1%) including 61 women with one of the original three mutations (C61G, 4153delA, 5382insC) and 22 women with a different mutation (1.9%). Three new mutations (3819del5, 185delAG and 5370C>T) were seen in multiple families. By including these three mutations in the extended panel, the mutant frequency increased from 5.2 to 6.7%. Polish women with breast cancer diagnosed at age of 50 or below should be screened with a panel of six founder mutations of BRCA1 (C61G, 4153delA, 5382insC, 3819del5, 185delAG and 5370C>T).

Age at diagnosis predicts local recurrence in women treated with breast-conserving surgery and postoperative radiation therapy for ductal carcinoma in situ: a population-based outcomes analysis

PURPOSE

The main goal of treating ductal carcinoma in situ (dcis) is to prevent the development of invasive breast cancer. Most women are treated with breast-conserving surgery (bcs) and radiotherapy. Age at diagnosis may be a risk factor for recurrence, leading to concerns that additional treatment may be necessary for younger women. We report a population-based study of women with dcis treated with bcs and radiotherapy and an evaluation of the effect of age on local recurrence (lr).

METHODS

All women diagnosed with dcis in Ontario from 1994 to 2003 were identified. Treatments and outcomes were collected through administrative databases and validated by chart review. Women treated with bcs and radiotherapy were included. Survival analyses were performed to evaluate the effect of age on outcomes.

RESULTS

We identified 5752 cases of dcis; 1607 women received bcs and radiotherapy. The median follow-up was 10.0 years. The 10-year cumulative lr rate was 27% for women younger than 45 years, 14% for women 45-50 years, and 11% for women more than 50 years of age (p < 0.0001). The 10-year cumulative invasive lr rate was 22% for women younger than 45 years, 10% for women 45-50 years, and 7% for women more than 50 years of age (p < 0.0001). On multivariate analyses, young age (<45 years) was significantly associated with lr and invasive lr [hazard ratio (hr) for lr: 2.6; 95% confidence interval (ci): 1.9 to 3.7; p < 0.0001; hr for invasive lr: 3.0; 95% ci: 2.0 to 4.4; p < 0.0001]. An age of 45-50 years was also significantly associated with invasive lr (hr: 1.6; 95% ci: 1.0 to 2.4; p = 0.04).

CONCLUSIONS

Age at diagnosis is a strong predictor of lr in women with dcis after treatment with bcs and radiotherapy.

Are two-centimeter breast cancers large or small?

BACKGROUND

Node-negative breast cancers from 2 cm to 5 cm in size are classified as stage ii, and smaller cancers, as stage i. We sought to determine if the prognosis of women with a breast cancer exactly 2 cm in size more closely resembles that of women with a stage i or a stage ii breast cancer.

METHODS

Using a cohort of 4265 young women with breast cancer, we compared the 10-year breast cancer mortality rates for women who had a tumour 0.1-1.9 cm, exactly 2.0 cm, and 2.1-2.9 cm.

RESULTS

In the first 3 years after diagnosis, the survival pattern of women with a 2.0-cm breast cancer was nearly identical to that of women with a larger cancer (2.1-3.0 cm). From year 3 to year 10, the relative survival of women with a 2.0-cm breast cancer was improved and nearly identical to that of women with a smaller cancer. The 10-year survival rate was 89.3% for women with tumours less than 20 mm, 86.1% for women with tumours equal to 20 mm, and 81.2% for women with 21-mm to 29-mm tumours.

CONCLUSIONS

For young women with small breast cancers, the relative mortality from breast cancer is dynamic with increasing tumour size and varies with time from diagnosis.

Clinical implications of genetic testing for BRCA1 and BRCA2 mutations in Austria

The objective of this study was to describe the experience of genetic testing in Austrian women with a BRCA1 or BRCA2 mutation in terms of preventive measures taken and incident cancers diagnosed. We collected clinical information on 246 Austrian women with a BRCA1 or BRCA2 mutation tested between 1995 and 2012 and followed 182 of them for an average of 6.5 years. Of the 90 women who were cancer-free at baseline, 21.4% underwent preventive bilateral mastectomy, 46.1% had preventive bilateral salpingo-oophorectomy, and 1 took tamoxifen; 58.8% of the at-risk women underwent at least one screening breast magnetic resonance imaging (MRI). Of the 85 women with breast cancer, 69.4% had a unilateral mastectomy or lumpectomy and 30.6% had a contralateral mastectomy. In the follow-up period, 14 new invasive breast cancers (6 first primary and 8 contralateral), 1 ductal carcinoma in situ case, 2 incident ovarian cancer cases, and 1 peritoneal cancer were diagnosed. In Austria, the majority of healthy women with a BRCA1 or BRCA2 mutation opt for preventive oophorectomy and MRI screening to manage their breast cancer risk; few have preventive mastectomy or take tamoxifen.

A model for breast cancer risk based on stem-cell theory

Recent studies of cells in culture and of mice models support the notion that the mammary stem cell is a precursor to the breast cancer cell 1–4. [...]

A comparison of the detection of BRCA mutation carriers through the provision of Jewish population-based genetic testing compared with clinic-based genetic testing

BACKGROUND

Guidelines for genetic testing for BRCA1 or BRCA2 stipulate that a personal or family history of cancer is necessary to be eligible for testing. Approximately 2% of Ashkenazi Jewish women carry a mutation, but to date population-based testing has not been advocated. Little is known about the relative yield of a conventional genetic testing programme versus a programme of widespread testing in a population with common founder mutations.

METHODS

We provided both referral-based and Jewish population-based testing between 2008 and 2012. We compared the numbers of BRCA mutation carriers identified through the two streams and estimated the number of genetic counselling hours devoted to each programme.

RESULTS

From 2008 to 2012, 38 female carriers were identified through 487 referrals to our genetics centre (29 unaffected with cancer). During the same time, 6179 Jewish women were tested through our population-based programme and 93 mutation carriers were identified (92 unaffected with cancer). Fewer counsellor hours were devoted to the population-based than to the clinical referral-based testing programme.

CONCLUSION

Genetic testing of all Jewish women above the age of 25 years will greatly expand the number of BRCA mutation carriers identified without a commensurate increase in the number of hours required for counselling.

Salpingectomy to prevent ovarian cancer: A Countercurrents Series

When Pamela Fayerman received a grant of $20,000 from the Canadian Institutes of Health Research in 2012 to pursue health journalism research, she was able to travel throughout Canada to interview experts about a possible new way to prevent ovarian cancer.[...]

Modes of delivery of genetic testing services and the uptake of cancer risk management strategies in BRCA1 and BRCA2 carriers

BRCA testing services are now offered by various healthcare providers, thus it is important to evaluate whether the implementation of cancer risk management (CRM) strategies varies by service provider. Using a registry-based sample of 795 female BRCA mutation carriers, we explored the association between uptake of CRM strategies with duration of genetic counseling (GC) sessions, provider type, and other demographic and clinical variables. All participants completed a baseline questionnaire. Information about uptake of CRM strategies was collected for a subset of 438 participants who completed additional questions. Summary statistics and Pearson chi-squared analysis were used to examine the associations between demographic and clinical variables with service delivery factors and with the uptake of various CRM strategies. Overall uptake of CRM strategies was high across all provider types. However, GC sessions were longer when provided by a genetics professional than by another provider (p < 0.001). Furthermore, higher frequencies of uptake of most CRM strategies were associated with longer GC sessions and when testing was performed by a genetics professional. Identification of factors to optimize delivery of these specialized GC services is important to maximize implementation of CRM strategies in BRCA carriers.

Breast cancer and the environment: what is left to learn?: A Countercurrents Series

Public interest in the link between the environment and breast cancer has waxed in recent months. [...]

Promoter methylation of BRCA1 in triple-negative breast cancer predicts sensitivity to adjuvant chemotherapy

BACKGROUND

BRCA1 function is inactivated through BRCA1 promoter methylation in a substantial number of triple-negative breast cancers. We investigated the impact of BRCA1-methylation status on the efficacy of adjuvant chemotherapy in patients with triple-negative breast cancer or with non-triple-negative breast cancer.

METHODS

BRCA1 promoter methylation was assessed in 1163 unselected breast cancer patients. Methylation was evaluated using a methylation-specific PCR (MSP) assay.

RESULTS

In the subgroup of 167 triple-negative breast cancer patients who received adjuvant chemotherapy, patients with BRCA1-methylated tumors had a superior 10-year disease-free survival (DFS)(78% versus 55%, P = 0.009) and 10-year disease-specific survival (DSS) (85% versus 69%, P = 0.024) than those with BRCA1-unmethylated tumors, and BRCA1 methylation was an independent favorable predictor of DFS and DSS in a multivariate analysis in this subgroup [DFS: hazard ratio (HR) = 0.45; 95% confidence interval (CI) 0.24-0.84; P = 0.019; DSS: HR = 0.43; 95% CI = 0.19-0.95; P = 0.044]. In contrast, in 675 non-triple-negative breast cancer patients who received adjuvant chemotherapy, BRCA1 methylation was an unfavorable predictor of DFS and DSS in univariate analysis (DFS: HR = 1.56; 95% CI 1.16-2.12; P = 0.003; DSS: HR = 1.53; 95% CI = 1.05-2.21; P = 0.026).

CONCLUSIONS

Triple-negative breast cancer patients with BRCA1-methylated tumors are sensitive to adjuvant chemotherapy and have a favorable survival compared with patients with BRCA1-unmethylated triple-negative tumors.

Tumour size predicts long-term survival among women with lymph node-positive breast cancer

BACKGROUND

The benefit of early detection of breast cancer is assumed to be achieved primarily by identifying disease before it has spread beyond the breast. In support of early detection, the survival experience of women with breast cancer decreases as the mean size of the cancer increases. It is not clear if women with regional spread (node-positive breast cancer) benefit from early detection to the same extent that women with node-negative breast cancer do.

METHODS

A review was conducted of the survival experience of 1894 patients with invasive breast cancers 5.0 cm or less in size. Cases were divided into node-positive and node-negative, and tumours were categorized by size (0.1-1.0 cm, 1.1-2.0 cm, and 2.1-5.0 cm). After a mean follow-up of 9.9 years, 368 cancer-specific deaths had occurred in the cohort. The effect of tumour size on 15-year survival for subgroups of women with node-positive and node-negative breast cancer was estimated.

RESULTS

Tumour size was a strong predictor of 15-year survival in both the node-positive and node-negative cancer subgroups. A decline of 1.0 cm in size was associated with a reduction in 15-year mortality of 10.3% in the node-positive group and of 2.5% in the node-negative group. A decline of approximately 1.5 cm was associated with a reduction in mortality of 23.0% in the node-positive group and of 10.8% in the node-negative group.

CONCLUSIONS

The impact of decreasing tumour size on 15-year survival is much greater for women with node-positive than for women with node-negative breast cancers. Contrary to expectation, the benefit of screening is likely to be greater for women with relatively advanced breast cancer than for women with earlystage disease.