Lorraine Durcan

Inherited Mutations in 17 Breast Cancer Susceptibility Genes Among a Large Triple-Negative Breast Cancer Cohort Unselected for Family History of Breast Cancer

PURPOSE Recent advances in DNA sequencing have led to the development of breast cancer susceptibility gene panels for germline genetic testing of patients. We assessed the frequency of mutations in 17 predisposition genes, including BRCA1 and BRCA2, in a large cohort of patients with triple-negative breast cancer (TNBC) unselected for family history of breast or ovarian cancer to determine the utility of germline genetic testing for those with TNBC. PATIENTS AND METHODS Patients with TNBC (N = 1,824) unselected for family history of breast or ovarian cancer were recruited through 12 studies, and germline DNA was sequenced to identify mutations. RESULTS Deleterious mutations were identified in 14.6% of all patients. Of these, 11.2% had mutations in the BRCA1 (8.5%) and BRCA2 (2.7%) genes. Deleterious mutations in 15 other predisposition genes were detected in 3.7% of patients, with the majority observed in genes involved in homologous recombination, including PALB2 (1.2%) and BARD1, RAD51D, RAD51C, and BRIP1 (0.3% to 0.5%). Patients with TNBC with mutations were diagnosed at an earlier age (P < .001) and had higher-grade tumors (P = .01) than those without mutations. CONCLUSION Deleterious mutations in predisposition genes are present at high frequency in patients with TNBC unselected for family history of cancer. Mutation prevalence estimates suggest that patients with TNBC, regardless of age at diagnosis or family history of cancer, should be considered for germline genetic testing of BRCA1 and BRCA2. Although mutations in other predisposition genes are observed among patients with TNBC, better cancer risk estimates are needed before these mutations are used for clinical risk assessment in relatives.

Common Breast Cancer Susceptibility Loci Are Associated with Triple-Negative Breast Cancer

Triple-negative breast cancers are an aggressive subtype of breast cancer with poor survival, but there remains little known about the etiologic factors that promote its initiation and development. Commonly inherited breast cancer risk factors identified through genome-wide association studies display heterogeneity of effect among breast cancer subtypes as defined by the status of estrogen and progesterone receptors. In the Triple Negative Breast Cancer Consortium (TNBCC), 22 common breast cancer susceptibility variants were investigated in 2,980 Caucasian women with triple-negative breast cancer and 4,978 healthy controls. We identified six single-nucleotide polymorphisms, including rs2046210 (ESR1), rs12662670 (ESR1), rs3803662 (TOX3), rs999737 (RAD51L1), rs8170 (19p13.1), and rs8100241 (19p13.1), significantly associated with the risk of triple-negative breast cancer. Together, our results provide convincing evidence of genetic susceptibility for triple-negative breast cancer.

Prospective Observational Study of Breast Cancer Treatment Outcomes for UK Women Aged 18–40 Years at Diagnosis: The POSH Study

BACKGROUND Breast cancer at a young age is associated with poor prognosis. The Prospective Study of Outcomes in Sporadic and Hereditary Breast Cancer (POSH) was designed to investigate factors affecting prognosis in this patient group. METHODS Between 2000 and 2008, 2956 patients aged 40 years or younger were recruited to a UK multicenter prospective observational cohort study (POSH). Details of tumor pathology, disease stage, treatment received, and outcome were recorded. Overall survival (OS) and distant disease-free interval (DDFI) were assessed using Kaplan-Meier curves. All statistical tests were two-sided. RESULTS Median age of patients was 36 years. Median tumor diameter was 22 mm, and 50% of patients had positive lymph nodes; 59% of tumors were grade 3, 33.7% were estrogen receptor (ER) negative, and 24% were human epidermal growth factor receptor 2 (HER2) positive. Five-year OS was higher for patients with ER-positive than ER-negative tumors (85.0%, 95% confidence interval [CI] = 83.2% to 86.7% vs 75.7%, 95% CI = 72.8% to 78.4%; P < .001), but by eight years, survival was almost equal. The eight-year OS of patients with ER-positive tumors was similar to that of patients with ER-negative tumors in both HER2-positive and HER2-negative subgroups. The flexible parametric survival model for OS shows that the risk of death increases steadily over time for patients with ER-positive tumors in contrast to patients with ER-negative tumors, where risk of death peaked at two years. CONCLUSIONS These results confirm the increased frequency of ER-negative tumors and early relapse in young patients and also demonstrate the equally poor longer-term outlook of young patients who have ER-positive tumors with HER2-negative or -positive disease.

Obesity and the outcome of young breast cancer patients in the UK: the POSH study

BACKGROUND Obese breast cancer patients have a poorer prognosis than non-obese patients. We examined data from a large prospective cohort study to explore the associations of obesity with tumour pathology, treatment and outcome in young British breast cancer patients receiving modern oncological treatments. PATIENTS AND METHODS A total of 2956 patients aged ≤40 at breast cancer diagnosis were recruited from 126 UK hospitals from 2001 to 2007. Height and weight were measured at registration. Tumour pathology and treatment details were collected. Follow-up data were collected at 6, 12 months, and annually. RESULTS A total of 2843 eligible patients (96.2%) had a body mass index (BMI) recorded: 1526 (53.7%) were under/healthy-weight (U/H, BMI <25 kg/m(2)), 784 (27.6%) were overweight (ov, BMI ≥25 to <30), and 533 (18.7%) were obese (ob, BMI ≥30). The median tumour size was significantly higher in obese and overweight patients than U/H patients (Ob 26 mm versus U/H 20 mm, P < 0.001; Ov 24 mm versus U/H 20 mm, P < 0.001). Obese and overweight patients had significantly more grade 3 tumours (63.9% versus 59.0%, P = 0.048; Ov 63.6% versus U/H 59.0% P = 0.034) and node-positive tumours (Ob 54.6% versus U/H 49.0%, P = 0.027; Ov 54.2% versus U/H 49%, P = 0.019) than U/H patients. Obese patients had more ER/PR/HER2-negative tumours than healthy-weight patients (25.0% versus 18.3%, P = 0.001). Eight-year overall survival (OS) and distant disease-free interval (DDFI) were significantly lower in obese patients than healthy-weight patients [OS: hazard ratio (HR) 1.65, P < 0.001; DDFI: HR 1.44, P < 0.001]. Multivariable analyses adjusting for tumour grade, size, nodal, and HER2 status indicated that obesity was a significant independent predictor of OS and DDFI in patients with ER-positive disease. CONCLUSIONS Young obese breast cancer patients present with adverse tumour characteristics. Despite adjustment for this, obesity still independently predicts DDFI and OS.BACKGROUND Obese breast cancer patients have a poorer prognosis than non-obese patients. We examined data from a large prospective cohort study to explore the associations of obesity with tumour pathology, treatment and outcome in young British breast cancer patients receiving modern oncological treatments. PATIENTS AND METHODS A total of 2956 patients aged ≤40 at breast cancer diagnosis were recruited from 126 UK hospitals from 2001 to 2007. Height and weight were measured at registration. Tumour pathology and treatment details were collected. Follow-up data were collected at 6, 12 months, and annually. RESULTS A total of 2843 eligible patients (96.2%) had a body mass index (BMI) recorded: 1526 (53.7%) were under/healthy-weight (U/H, BMI <25 kg/m2), 784 (27.6%) were overweight (ov, BMI ≥25 to <30), and 533 (18.7%) were obese (ob, BMI ≥30). The median tumour size was significantly higher in obese and overweight patients than U/H patients (Ob 26mm versus U/H 20mm, P < 0.001; Ov 24mm versus U/H 20mm, P < 0.001). Obese and overweight patients had significantly more grade 3 tumours (63.9% versus 59.0%, P = 0.048; Ov 63.6% versus U/H 59.0% P = 0.034) and node-positive tumours (Ob 54.6% versus U/H 49.0%, P = 0.027; Ov 54.2% versus U/H 49%, P = 0.019) than U/H patients. Obese patients had more ER/PR/HER2-negative tumours than healthy-weight patients (25.0% versus 18.3%, P = 0.001). Eight-year overall survival (OS) and distant disease-free interval (DDFI) were significantly lower in obese patients than healthy-weight patients [OS: hazard ratio (HR) 1.65, P < 0.001; DDFI: HR 1.44, P < 0.001]. Multivariable analyses adjusting for tumour grade, size, nodal, and HER2 status indicated that obesity was a significant independent predictor of OS and DDFI in patients with ER-positive disease. CONCLUSIONS Young obese breast cancer patients present with adverse tumour characteristics. Despite adjustment for this, obesity still independently predicts DDFI and OS.

Ethnicity and outcome of young breast cancer patients in the United Kingdom: the POSH study.

Background:Black ethnic groups have a higher breast cancer mortality than Whites. American studies have identified variations in tumour biology and unequal health-care access as causative factors. We compared tumour pathology, treatment and outcomes in three ethnic groups in young breast cancer patients treated in the United Kingdom.Methods:Women aged ⩽40 years at breast cancer diagnosis were recruited to the POSH national cohort study (MREC: 00/06/69). Personal characteristics, tumour pathology and treatment data were collected at diagnosis. Follow-up data were collected annually. Overall survival (OS) and distant relapse-free survival (DRFS) were assessed using Kaplan–Meier curves, and multivariate analyses were performed using Cox regression.Results:Ethnicity data were available for 2915 patients including 2690 (91.0%) Whites, 118 (4.0%) Blacks and 87 (2.9%) Asians. Median tumour diameter at presentation was greater in Blacks than Whites (26.0 mm vs 22.0 mm, P=0.0103), and multifocal tumours were more frequent in both Blacks (43.4%) and Asians (37.0%) than Whites (28.9%). ER/PR/HER2-negative tumours were significantly more frequent in Blacks (26.1%) than Whites (18.6%, P=0.043). Use of chemotherapy was similarly high in all ethnic groups (89% B vs 88.6% W vs 89.7% A). A 5-year DRFS was significantly lower in Blacks than Asians (62.8% B vs 77.0% A, P=0.0473) or Whites (62.8 B% vs 77.0% W, P=0.0053) and a 5-year OS for Black patients, 71.1% (95% CI: 61.0–79.1%), was significantly lower than that of Whites (82.4%, 95% CI: 80.8–83.9%, W vs B: P=0.0160). In multivariate analysis, Black ethnicity had an effect on DRFS in oestrogen receptor (ER)-positive patients that is independent of body mass index, tumour size, grade or nodal status, HR: 1.60 (95% CI: 1.03–2.47, P=0.035).Conclusion:Despite equal access to health care, young Black women in the United Kingdom have a significantly poorer outcome than White patients. Black ethnicity is an independent risk factor for reduced DRFS particularly in ER-positive patients.

Germline BRCA mutation and outcome in young-onset breast cancer (POSH): a prospective cohort study

Summary Background Retrospective studies provide conflicting interpretations of the effect of inherited genetic factors on the prognosis of patients with breast cancer. The primary aim of this study was to determine the effect of a germline BRCA1 or BRCA2 mutation on breast cancer outcomes in patients with young-onset breast cancer. Methods We did a prospective cohort study of female patients recruited from 127 hospitals in the UK aged 40 years or younger at first diagnosis (by histological confirmation) of invasive breast cancer. Patients with a previous invasive malignancy (except non-melanomatous skin cancer) were excluded. Patients were identified within 12 months of initial diagnosis. BRCA1 and BRCA2 mutations were identified using blood DNA collected at recruitment. Clinicopathological data, and data regarding treatment and long-term outcomes, including date and site of disease recurrence, were collected from routine medical records at 6 months, 12 months, and then annually until death or loss to follow-up. The primary outcome was overall survival for all BRCA1 or BRCA2 mutation carriers (BRCA-positive) versus all non-carriers (BRCA-negative) at 2 years, 5 years, and 10 years after diagnosis. A prespecified subgroup analysis of overall survival was done in patients with triple-negative breast cancer. Recruitment was completed in 2008, and long-term follow-up is continuing. Findings Between Jan 24, 2000, and Jan 24, 2008, we recruited 2733 women. Genotyping detected a pathogenic BRCA mutation in 338 (12%) patients (201 with BRCA1, 137 with BRCA2). After a median follow-up of 8·2 years (IQR 6·0–9·9), 651 (96%) of 678 deaths were due to breast cancer. There was no significant difference in overall survival between BRCA-positive and BRCA-negative patients in multivariable analyses at any timepoint (at 2 years: 97·0% [95% CI 94·5–98·4] vs 96·6% [95·8–97·3]; at 5 years: 83·8% [79·3–87·5] vs 85·0% [83·5–86·4]; at 10 years: 73·4% [67·4–78·5] vs 70·1% [67·7–72·3]; hazard ratio [HR] 0·96 [95% CI 0·76–1·22]; p=0·76). Of 558 patients with triple-negative breast cancer, BRCA mutation carriers had better overall survival than non-carriers at 2 years (95% [95% CI 89–97] vs 91% [88–94]; HR 0·59 [95% CI 0·35–0·99]; p=0·047) but not 5 years (81% [73–87] vs 74% [70–78]; HR 1·13 [0·70–1·84]; p=0·62) or 10 years (72% [62–80] vs 69% [63–74]; HR 2·12 [0·82–5·49]; p= 0·12). Interpretation Patients with young-onset breast cancer who carry a BRCA mutation have similar survival as non-carriers. However, BRCA mutation carriers with triple-negative breast cancer might have a survival advantage during the first few years after diagnosis compared with non-carriers. Decisions about timing of additional surgery aimed at reducing future second primary-cancer risks should take into account patient prognosis associated with the first malignancy and patient preferences. Funding Cancer Research UK, the UK National Cancer Research Network, the Wessex Cancer Trust, Breast Cancer Now, and the PPP Healthcare Medical Trust Grant.

Family history and outcome of young patients with breast cancer in the UK (POSH study).

Young patients presenting to surgical clinics with breast cancer are usually aware of their family history and frequently believe that a positive family history may adversely affect their prognosis. Tumour pathology and outcomes were compared in young British patients with breast cancer with and without a family history of breast cancer.

Local Recurrence and Breast Oncological Surgery in Young Women With Breast Cancer: The POSH Observational Cohort Study.

Objective: To assess clinical and surgical factors affecting local recurrence and survival in young breast cancer patients in the Prospective study of Outcomes in Sporadic versus Hereditary breast cancer (POSH). Background: Emerging data suggest young age is a predictor of increased local recurrence. Methods: POSH is a prospective cohort of 3024 women of 18 to 40 years with breast cancer. Cohort characteristics were grouped by mastectomy or BCS. Endpoints were local-recurrence interval (LRI), distant disease-free interval (DDFI), and overall survival (OS); described using cumulative-hazard and Kaplan-Meier plots and multivariable analyses by Flexible Parametric and Cox regression models. Results: Mastectomy was performed in 1464 patients and breast-conserving surgery (BCS) in 1395. Patients undergoing mastectomy had larger tumors and higher proportions of positive family history, estrogen receptor+, progesterone receptor+, and/or human epidermal growth factor receptor 2+ tumors. Local events accounted for 15% of recurrences. LRI by surgical type varied over time with LRI similar at 18 months (1.0% vs 1.0%, P = 0.348) but higher for BCS at 5 and 10 years (5.3% vs 2.6%, P < 0.001; and 11.7% vs 4.9%, P < 0.001, respectively). Similar results were found in the adjusted model. Conversely, distant-metastases and deaths were lower for BCS but not after adjusting for prognostic factors. After mastectomy chest-wall radiotherapy was associated with improved LRI (hazard ratio, HR = 0.46, P = 0.015). Positive surgical margins, and development of local recurrence predicted for reduced DDFI (HR = 0.50, P < 0.001; and HR = 0.29, P = 0.001, respectively). Conclusions: Surgical extent appears less important for DDFI than completeness of excision or, where appropriate, chest-wall radiotherapy. Despite higher local-recurrence rates for BCS, surgical type does not influence DDFI or OS after adjusting for known prognostic factors in young breast cancer patients.

An evaluation of the prognostic model PREDICT using the POSH cohort of women aged ⩽40 years at breast cancer diagnosis

Background:Breast cancer is the most common cancer in younger women (aged ⩽40 years) in the United Kingdom. PREDICT (http://www.predict.nhs.uk) is an online prognostic tool developed to help determine the best available treatment and outcome for early breast cancer. This study was conducted to establish how well PREDICT performs in estimating survival in a large cohort of younger women recruited to the UK POSH study.Methods:The POSH cohort includes data from 3000 women aged ⩽40 years at breast cancer diagnosis. Study end points were overall and breast cancer-specific survival at 5, 8, and 10 years. Evaluation of PREDICT included model discrimination and comparison of the number of predicted versus observed events.Results:PREDICT provided accurate long-term (8- and 10-year) survival estimates for younger women. Five-year estimates were less accurate, with the tool overestimating survival by 25% overall, and by 56% for patients with oestrogen receptor (ER)-positive tumours. PREDICT underestimated survival at 5 years among patients with ER-negative tumours.Conclusions:PREDICT is a useful tool for providing reliable long-term (10-year) survival estimates for younger patients. However, for more accurate short-term estimates, the model requires further calibration using more data from young onset cases. Short-term prediction may be most relevant for the increasing number of women considering risk-reducing bilateral mastectomy.

Genetic testing in a cohort of young patients with HER2-amplified breast cancer

BACKGROUND Young age at diagnosis for breast cancer raises the question of genetic susceptibility. We explored breast cancer susceptibility genes testing on ≤40-year-old patients with HER2-amplified invasive breast cancer. PATIENTS AND METHODS Patients were selected from a large UK cohort study. The inclusion criterion was age ≤40 at diagnosis with confirmed HER2-amplified breast cancer. The probability of finding a BRCA gene mutation was calculated based on family history. Genetic testing used was either clinical testing for BRCA1 and BRCA2, with a subset also tested for TP53 mutations, or research-based testing using a typical panel comprising 17 breast cancer susceptibility genes (CSGs) including BRCA1, BRCA2 and TP53. RESULTS Of the 591 eligible patients, clinical testing results were available for 133 cases and an additional 263 cases had panel testing results. BRCA testing across 396 cases found 8 BRCA2 (2%) and 6 BRCA1 (2%) pathogenic mutations. Of the 304 patients tested for TP53 mutations, overall 9 (3%) had deleterious TP53 mutations. Of the 396 patients, 101 (26%) met clinical criteria for BRCA testing (≥10% probability), among whom 11% had pathogenic BRCA mutations (6 BRCA2, 5 BRCA1). Where the probability was calculated to be <10%, only 4 of 295 (1%) patients had BRCA mutations. Among the 59 patients who had TP53 testing meeting the 10% threshold, 7 had mutations (12%). Likely functionally deleterious mutations in 14 lower penetrance CSGs were present in 12 of 263 (5%) panel-tested patients. CONCLUSION Patients aged <41 at diagnosis with HER2+ breast cancer and no family history of breast cancer can be reassured that they have a low chance of being a high-risk gene carrier. If there is a strong family history, not only BRCA but also TP53 gene testing should be considered. The clinical utility of testing lower penetrance CSGs remains unclear.