Prognostic role of BRCA1 mutation in patients with triple-negative breast cancer

Long-term outcomes of young, node-negative, chemotherapy-naïve, triple-negative breast cancer patients according to BRCA1 status

BACKGROUND

Due to the abundant usage of chemotherapy in young triple-negative breast cancer (TNBC) patients, the unbiased prognostic value of BRCA1-related biomarkers in this population remains unclear. In addition, whether BRCA1-related biomarkers modify the well-established prognostic value of stromal tumor-infiltrating lymphocytes (sTILs) is unknown. This study aimed to compare the outcomes of young, node-negative, chemotherapy-naïve TNBC patients according to BRCA1 status, taking sTILs into account.

METHODS

We included 485 Dutch women diagnosed with node-negative TNBC under age 40 between 1989 and 2000. During this period, these women were considered low-risk and did not receive chemotherapy. BRCA1 status, including pathogenic germline BRCA1 mutation (gBRCA1m), somatic BRCA1 mutation (sBRCA1m), and tumor BRCA1 promoter methylation (BRCA1-PM), was assessed using DNA from formalin-fixed paraffin-embedded tissue. sTILs were assessed according to the international guideline. Patients' outcomes were compared using Cox regression and competing risk models.

RESULTS

Among the 399 patients with BRCA1 status, 26.3% had a gBRCA1m, 5.3% had a sBRCA1m, 36.6% had tumor BRCA1-PM, and 31.8% had BRCA1-non-altered tumors. Compared to BRCA1-non-alteration, gBRCA1m was associated with worse overall survival (OS) from the fourth year after diagnosis (adjusted HR, 2.11; 95% CI, 1.18-3.75), and this association attenuated after adjustment for second primary tumors. Every 10% sTIL increment was associated with 16% higher OS (adjusted HR, 0.84; 95% CI, 0.78-0.90) in gBRCA1m, sBRCA1m, or BRCA1-non-altered patients and 31% higher OS in tumor BRCA1-PM patients. Among the 66 patients with tumor BRCA1-PM and ≥ 50% sTILs, we observed excellent 15-year OS (97.0%; 95% CI, 92.9-100%). Conversely, among the 61 patients with gBRCA1m and < 50% sTILs, we observed poor 15-year OS (50.8%; 95% CI, 39.7-65.0%). Furthermore, gBRCA1m was associated with higher (adjusted subdistribution HR, 4.04; 95% CI, 2.29-7.13) and tumor BRCA1-PM with lower (adjusted subdistribution HR, 0.42; 95% CI, 0.19-0.95) incidence of second primary tumors, compared to BRCA1-non-alteration.

CONCLUSIONS

Although both gBRCA1m and tumor BRCA1-PM alter BRCA1 gene transcription, they are associated with different outcomes in young, node-negative, chemotherapy-naïve TNBC patients. By combining sTILs and BRCA1 status for risk classification, we were able to identify potential subgroups in this population to intensify and optimize adjuvant treatment.

Risk of metastasis in BRCA2 carriers diagnosed with triple-negative breast cancer

BACKGROUND

Triple-negative breast cancer (TNBC) is the neoplasia most associated with BRCA1 germline pathogenic variants (PV) and is more likely to develop metastases than the other breast cancer (BC) subtypes, mainly in the lungs and the central nervous system (CNS). Recently, BRCA2 carriers were shown to have a higher risk for developing CNS metastases. However, the patterns of recurrence and metastases of BRCA2 carriers with TNBC are unknown.

METHODS

TNBC patient data attending the A.C. Camargo Cancer Center, from 1998 through 2020, were verified either by medical records or by BRCA1/2 genetic testing carried out. Multivariable logistic regression models were fit to the data to assess the independent factors for bone and CNS metastases. Adjustment was done using all independent variables with p < 0.2 in the univariable Cox model to describe the relationship between the independent variables until time of death.

RESULTS

A total of 388 TNBC patients were evaluated. We identified PV in BRCA1/2 genes in 21% (82/388), being 17.7% (69/388) in BRCA1 and only 3.3% (13/388) in BRCA2. A total of 120 patients (31%) developed distant metastases. Bone or CNS metastases were observed in 40% and 60% of BRCA2 PV carriers (p = 0.155), respectively. The BRCA2 carriers tended to have a higher likelihood of developing bone metastases (OR, 4.06; 95% CI, 0.82-20.01; p = 0.085), when compared to BRCA1 carriers (OR, 0.6; 95% CI, 0.12-2.87; p = 0.528). BRCA2 carriers had an OR of 1.75 (95% CI, 0.33-9.14; p = 0.503) for CNS metastasis development, while BRCA1 carriers had an OR of 0.72 (95% CI, 0.23-2.23; p = 0.574).

CONCLUSIONS

Patients with TNBC and PV in the BRCA2 gene had higher frequencies of secondary bone involvement and CNS in the course of the disease. However, the BRCA2 PV did not represent an independent outcome predictor of metastases and overall survival. Efforts to increase the number of BRCA2 carriers among TNBC patients are crucial for determining their risk of developing bone and CNS metastases compared to BRCA2 noncarriers.

Progress and prospects in research and clinical practice of hormone receptor-positive, HER-2-negative breast cancer with BRCA1/2 mutations

Breast cancer (BC) is a heterogeneous disease that is the most common cancer in women worldwide. However, precise subtyping and corresponding treatments have improved patient outcomes. Hormone receptor (HR)-positive, human epidermal growth factor receptor type 2 (HER2)-negative (HR+/HER2-) BC with BRCA1 and/or BRCA2 mutations (BRCA1/2m) is a unique BC subset with dual drivers: homologous recombination deficiency and hormone receptor signaling. Wild-type BRCA1/2 suppresses estrogen receptor-mediated signaling. Loss-of-function mutations in BRCA1/2 release estrogen receptor suppression, leading to reduced sensitivity to endocrine therapy. Poly (ADP-ribose) polymerase (PARP) inhibitors (PARPis) exert antitumor effects against this subtype and can be used in combination with endocrine therapy. Although PARPis have been evaluated in metastatic triple-negative breast cancer, their efficacy against HR+/HER2- BC has not been clearly established. The present review summarizes recent advances and prospects in the progress of the HR+/HER2-/BRCA1/2m subgroup. As such, this article provides theoretical guidance for future research and promotes the use of PARPis for the treatment of HR+/HER2-/BRCA1/2m BC.

Contribution of BRCA1 5382insC mutation to triplene-gative and luminal types of breast cancer in Ukraine

PURPOSE

The gene BRCA1 plays a key role in DNA repair in breast and ovarian cell lines and this is considered one of target tumor suppressor genes in same line of cancers. The 5382insC mutation is among the most frequently detected in patients (Eastern Europe) with triple-negative breast cancer (TNBC). In Ukraine, there is not enough awareness of necessity to test patients with TNBC for BRCA1 mutations. That is why this group of patients is not well-studied, even through is known the mutation may affect the course of disease.

METHODS

The biological samples of 408 female patients were analyzed of the 5382insC mutation in BRCA1. We compared the frequency of the 5382insC mutation in BRCA1 gene observed in Ukraine with known frequencies in other countries.

RESULTS

For patients with TNBC, BRCA1 mutations frequency was 11.3%, while in patients with luminal types of breast cancers, the frequency was 2.8%. Prevalence of 5382insC among TNBC patients reported in this study was not different from those in Tunisia, Poland, Russia, and Bulgaria, but was higher than in Australia and Germany.

CONCLUSION

The BRCA1 c.5382 mutation rate was recorded for the first time for TNBC patients in a Ukrainian population. The results presented in this study underscore the importance of this genetic testing of mutations in patients with TNBC. Our study supports BRCA1/2 genetic testing for all women diagnosed with TNBC, regardless of the age of onset or family history of cancer and not only for women diagnosed with TNBC at <60y.o., as guidelines recommend.

Prognostic Prediction of BRCA Mutations by 18F-FDG PET/CT SUVmax in Breast Cancer

Objectives:

This study aimed to investigate the prognostic prediction of germline BRCA1 and BRCA2 mutations by comparing the maximum standardized uptake value (SUV_max) obtained from ¹⁸fluoride-fluorodeoxyglucose positron emission tomography/computed tomography (¹⁸F-FDG PET/CT), which is considered a prognostic factor in breast cancer (BC).

Methods:

Retrospective interdisciplinary laboratory results of 92 patients with BC who had germline BRCA1 or BRCA2 mutation profiles and underwent ¹⁸F-FDG PET/CT were compared. Genotyping was made by next-generation sequencing, and PET/CT scans were re-evaluated. The histopathological data, genetic results, and clinical demographics of all patients were recorded. Patients were divided into two groups in accordance with the presence of germline BRCA1 and/or BRCA2 mutations. Between-group statistical comparison was performed.

Results:

In PET/CT performed for primary staging, patients with BRCA-positive BC had significantly higher SUV_max (p=0.039), larger tumor size (p=0.025), and presence of axillary nodal metastases (p=0.023) than patients with BRCA-negative BC. Although the Ki-67 index was higher in the BRCA-positive group than BRCA-negative group, this difference was not significant (p=0.157). Moreover, in the BRCA-positive and negative groups, SUV_max, Ki-67 index, and tumor size, grade, and stage were significantly correlated with each other.

Conclusion:

The results of this study showed a strong association between BRCA mutations and SUV_max, which indicates the poor prognosis of BC.

Evaluation of Complete Pathological Regression after Neoadjuvant Chemotherapy in Triple-Negative Breast Cancer Patients with BRCA1 Founder Mutation Aided Bayesian A/B Testing Approach

The aim of this study was to evaluate the probability of pathologic complete regression (pCR) by the BRCA1 gene mutation status in patients with triple-negative breast cancer (TNBC) treated with neoadjuvant chemotherapy. The study involved 143 women (mean age 55.4 ± 13.1 years) with TNBC. The BRCA1 mutation was observed in 17% of the subjects. The most commonly used (85.3%) chemotherapy regimen was four cycles of adriamycine and cyclophosphamide followed by 12 cycles of paclitaxel (4AC + 12T). The differences between clinico-pathological factors by BRCA1 status were estimated. Odds ratios and 95% confidence intervals for pCR vs. non-pCR were calculated using logistic regression. The probability distribution of pCR based on BRCA1 status was estimated using beta distributions. The presence of T3-T4 tumours, cancer in stages II and III, lymphovascular invasion, and the use of chemotherapy schedules other than 4AC + 12T significantly decreased the odds of pCR. It was established that there was a 20% chance that pCR in patients with the BRCA1 mutation was 50% or more times as frequent than in patients without the mutation. Thus, the BRCA1 mutation can be a predictive factor for pCR in patients with TNBC.

Prognostic Impact of BRCA1 and BRCA2 Mutations on Long-Term Survival Outcomes in Egyptian Female Breast Cancer Patients

Evidence on the prognostic relevance of BRCA1/2 mutations on breast cancer survival is still debatable. To address this ambiguity, we sought to elucidate the impact of BRCA1/2 mutation carriership on long-term clinical outcomes for the first time in Egyptian female breast cancer patients. This study comprised 103 Egyptian female breast cancer patients previously tested for BRCA1/2 mutations. Clinicopathological characteristics and long-term follow-up data were retrieved from clinical records until death or loss to follow-up. Overall survival (OS), recurrence-free survival (RFS), disease-free survival (DFS), and metastasis-free survival (MFS) were compared in BRCA1/2 mutation carriers and non-carriers. Pathogenic variants (Class 5 according to ACMG/AMP guidelines) were observed in 29 cases. The profile of the detected variants was previously reported. After median follow-up time of 6.9 years (range, 4.2-24.4 years), BRCA1/2 carriers exhibited significantly worse RFS compared to non-carriers (p = 0.01; HR = 3.00 (95%CI 1.35-6.68)). However, we couldn't demonstrate statistically significant difference between carriers of pathogenic mutations and non-carriers regarding MFS (p = 0.24; HR = 1.38 (95%CI 0.8-2.4)), DFS (p = 0.11; HR = 1.23 (95%CI 0.74-2.06)), or OS (p = 0.36; HR = 1.23 (95%CI 0.58-2.61)). Though no significant impact was observed in OS, yet BRCA1/2 mutation carriers were at high risk of recurrence, highlighting the importance of adopting BRCA screening strategies and prophylactic measures.

EGFR, BRCA1, BRCA2 and TP53 genetic profile in Moroccan triple negative breast cancer cases

Triple negative breast cancer account for 10% to 20% of all newly diagnosed breast cancer cases, this subtype is well known for its lack of estrogen, progesterone and HER2 expression unlike the other subtypes of breast cancer that usually express at least one of the three. The absence of a specific biomarker for TNBC has made his treatment very challenging and his death rates very high compared to the other subtypes. Therefore, in morocco, many studies have been conducted in the hope of finding a specific biomarker for TNBC, but none of these studies has analyzed the EGFR protein expression and its gene molecular profile and correlated the EGFR analyses results with the genetic profile of other genes. In this study, we analyzed EGFR protein expression and the molecular profile of EGFR, BRCA1, BRCA2 and TP53 genes in 47 TNBC patients. We conducted a retrospective study of 47 Moroccan patients diagnosed with triple negative breast cancer between early 2013 and 2016. In this study, we have analyzed the EGFR. Protein expression, for all the 47 TNBC patients using pharmDx Kit. Then we used the Ion Personal Genome Machine (PGM) and Ion Ampliseq BRCA1/2 panel and hotspot Cancer panel to analyze the molecular profile of BRCA1/2 genes and the hotspot regions of TP53 and EGFR genes. The statistical analysis was performed using IBM SPSS Statistics ver. From the 47 analyzed patients using EGFR pharmDx Kit only 16 (34%) had EGFR overexpression while 31 (66%), patients were normal, moreover, From the 47 TNBC patients, only 39 underwent Mutational analysis of EGFR, BRCA1/2, and TP53 genes. One patient harbored a BRCA1 mutation c.798_799delTT (p.Ser267Lys). While for TP53 gene, 16 patients out of 39 (41%) presented hotspot mutations, seven of them harbored c.743G>A (p.Arg248Gln) mutation, six patients harbored exon 6 mutations from which five harbored the mutation c.659A>G (p.Tyr220Cys) and one the mutation c.817C>T (p.Arg273Cys), and finally, three patients harbored the mutation c.524G>A (p.Arg175His). Regarding BRCA2 and EGFR sequencing results, no mutations or other genetic alterations were detected in 39 patients that were successfully sequenced. Statistical analysis revealed the absence of any correlations.

Effects of BRCA Germline Mutations on Triple-Negative Breast Cancer Prognosis

Germline BRCA1 and BRCA2 mutations confer an increased lifetime risk for breast cancer and ovarian cancer. Several studies have investigated prognosis among BRCA1/2 mutation carriers and noncarriers, but the prognostic impact on outcomes of breast cancer patients has not been determined. The aim of this study was to determine the prognosis of TNBC patients with and without BRCA1/2 germline mutation. Among 502 patients diagnosed with TNBC between 2005 and 2008, 124 patients with a strong family history of breast cancer or ovarian cancer as well as TNBC patients diagnosed under 45 years were referred to the Genetic Counseling Unit for genetic counselling and genetic tests. In 30 (24%) of them, the BRCA1/2 mutation was detected (the most common 5382insC in 18 (60%) patients). The median follow-up of the entire group was 60 months. BRCA1/2 mutation carriers were statistically significantly younger at TNBC diagnosis compared with nonmutation patients (41 vs 47 years, respectively). Patients with the BRCA1/2 mutation had smaller tumors (stage I: 47% vs 24.5% in noncarriers), but there was no significant difference in the regional nodal status (58.5–63% with cN0). Contralateral breast cancer developed in 26.5% of BRCA1/2 mutation carriers and in 14% of noncarriers. Other primary cancers were also slightly more common in BRCA1/2 mutation carriers (16.5% vs 9.5%). The performed analysis did not show any significant differences between the groups in recurrence-free survival (p=0.312). There was no significant difference between patients with or without BRCA1/2 mutation as regards overall survival (p=0.649) and the risk of TNBC death (p=0.333). The survival from detection of metastases was similar in two groups (p=0.865). Our study demonstrated that the BRCA1 mutation does not affect TNBC patients' outcomes.

Prevalence and oncologic outcomes of BRCA 1/2 mutations in unselected triple-negative breast cancer patients in Korea

PURPOSE

Triple-negative breast cancer (TNBC) accounts for 10-20% of all diagnosed BCs and it is enriched in BRCA1 mutation. Guidelines for Western countries suggest that BRCA 1/2 genetic testing should be done for patients with TNBC diagnosed less than 60 years, but there is lack of evidence supporting genetic testing in Asian populations. We determined the prevalence of germline BRCA 1/2 mutations among unselected Korean patients with TNBC and analyzed oncologic outcomes.

METHODS

From among 1628 women with TNBC who underwent surgery at Samsung Medical Center (SMC) between Jul 2008 and Jan 2016, 999 samples were available in the SMC biobank for testing germline BRCA 1/2 mutations using next-generation DNA sequencing.

RESULTS

Overall, 131 Korean patients (13.1%) had BRCA 1/2 mutations: 97 (9.7%) were in BRCA 1, and 35 (3.5%) were in BRCA 2. One patient had both BRCA 1 and BRCA 2 mutations. Overall, 68 distinct pathologic or likely pathogenic variants (43 BRCA1 and 25 BRCA2) were found. Among those diagnosed at ≤ 60 years, the prevalence of BRCA 1/2 mutation was 14.5%. The mean age of diagnosis of BRCA1/2 mutation carriers was significantly younger than that of non-carriers (45.6 vs. 50.1 years, p < 0.0001). The median follow-up duration was 53.6 months. There were no significant differences in disease-free survival, overall survival, or breast cancer-specific survival (p = 0.799, 0.092, and 0.124, respectively) between BRCA 1/2 carriers and non-carriers, although BRCA 1/2 carriers showed significantly worse contralateral breast cancer-free survival (p < 0.0001) than non-carriers.

CONCLUSION

In unselected TNBC patients, we found BRCA 1/2 mutations in 13.1% of overall patients and 14.5% of patients ≤ 60 years. We suggest that Korean women with TNBC diagnosed at ≤ 60 years should be tested for BRCA1/2 mutation.

Platinum-based neoadjuvant chemotherapy in BRCA1-positive breast cancer: a retrospective cohort analysis and literature review

Background

There is increasing evidence of high platinum sensitivity in BRCA-associated breast cancer. However, evidence from randomized trials is lacking. The aim of this study was to analyze the results of platinum-based chemotherapy for BRCA1-positive breast cancer in a neoadjuvant setting.

Methods

A retrospective study was performed by obtaining information from patient files. The results were compared with the available data from a literature review.

Results

Twelve female patients with BRCA1 gene mutations who had stage I to III breast cancers were eligible for evaluation. They received platinum-based neoadjuvant chemotherapy between 2011 and 2016. Eleven patients received a combination of cisplatin and doxorubicin, and one patient received carboplatin and docetaxel. All patients underwent mastectomy after chemotherapy. Ten patients (83%) achieved pathological complete remission (pCR). The observed pCR rate was comparable to existing results found in similar studies.

Conclusion

The results of the study confirm the high pCR rate in BRCA1-positive breast cancer after platinum-based neoadjuvant chemotherapy. Larger randomized studies and longer follow-up times are necessary to evaluate the role of platinum-based therapies in BRCA1-positive breast cancer.

Accumulation of cytoplasmic Cdk1 is associated with cancer growth and survival rate in epithelial ovarian cancer

Cyclin dependent kinase 1 (Cdk1) have previously reported correlation with cancer growth and a key regulator for cell cycle. Mostly, Cdk1′s function of nucleus for cell cycle is well known to be associated with cancer, but cytoplasmic Cdk1′s traits are not clearly identified, yet. We revealed that tissue microarray blocks of epithelial ovarian cancer (n = 249) showed increased level of cytoplasmic Cdk1 (p < 0.001), but not in nucleus (p = 0.192) of histologic cell type independently. On survival analysis, Cdk1 overexpression conferred a significantly worse prognosis in 5-year overall survival (Log-rank p = 0.028, Hazard ratio = 2.016, 95% CI = 1.097 to 4.635). Also, the expression of Cdk1 was increased in ovarian cancer cell lines and Gene Expression Omnibus datasets. When the expression and activity of Cdk1 were inhibited by si-Cdk1 or RO-3306 which is a potent Cdk1 inhibitor, the growth of ovarian cancer was diminished. Moreover, combined treatment with RO-3306 and cisplatin in ovarian cancer significantly elevated anti-cancer effects than single-agent treatment. In conclusion, cytoplasmic Cdk1 expression which was elevated in ovarian cancer predicts a poor overall survival. The inhibition of Cdk1 expression and activity reduced ovarian cancer growth.

Triple negative breast cancer in North of Morocco: clinicopathologic and prognostic features

Background

Triple Negative Breast Cancer (TNBC) is defined by a lack of estrogen and progesterone receptor gene expression and by the absence of overexpression on HER2. It is associated to a poor prognosis. We propose to analyze the clinicopathologic and prognostic characteristics of this breast cancer subtype in a Mediterranean population originated or resident in the North of Morocco.

Methods

We conducted a retrospective study of 279 patients diagnosed with breast cancer between January 2010 and January 2015. Clinicopathologic and prognostic features have been analyzed. Disease-Free Survival (DFS) and Overall Survival (OS) have been estimated.

Results

Of all cases, forty-nine (17.6 %) were identified as having triple negative breast cancer with a median age of 46 years. The average tumor size was 3.6 cm. The majority of patients have had invasive ductal carcinoma (91.8 %) and 40.4 % of them were grade III SBR. Nodal metastasis was detected in 38.9 % of the patients and vascular invasion was found in 36.6 % of them. About half of the patients had an early disease (53.1 %) and 46.9 % were diagnosed at an advanced stage. Patients with operable tumors (61.2 %) underwent primary surgery and adjuvant chemotherapy. Patients with no operable tumors (26.5 %) received neoadjuvant chemotherapy followed by surgery, and patients with metastatic disease (12.2 %) were treated by palliative chemotherapy. DFS and OS at 5 years were respectively 83.7 and 71.4 %. Among 49, twelve had recurrences, found either when diagnosing them or after a follow-up. Local relapse was 6.1 %. Lung and liver metastases accounted consecutively for 8.2 and 10.2 %. Bone metastases were found in 4.1 % and brain metastases in 2.1 % of the cases.

Conclusion

Our results are in accordance with literature data, particularly what concerning young age and poor prognosis among TNBC phenotype. Therefore, the identification of BRCA mutations in our population seems to be essential in order to better adapt management options for this aggressive form of breast cancer.

Effect of BRCA germline mutations on breast cancer prognosis: A systematic review and meta-analysis

BACKGROUND

The contribution of BRCA germline mutational status to breast cancer patients' prognosis is unclear. We aimed to systematically review and perform meta-analysis of the available evidence of effects of BRCA germline mutations on multiple survival outcomes of breast cancer patients as a whole and in specific subgroups of interest, including those with triple negative breast cancer, those with Ashkenazi Jewish ancestry, and patients with stage I-III disease.

METHODS

Sixty studies met all inclusion criteria and were considered for this meta-analysis. These studies involved 105,220 breast cancer patients, whose 3588 (3.4%) were BRCA mutations carriers. The associations between BRCA genes mutational status and overall survival (OS), breast cancer-specific survival (BCSS), recurrence-free survival (RFS), and distant metastasis-free survival (DMFS) were evaluated using random-effect models.

RESULTS

BRCA1 mutation carriers have worse OS than BRCA-negative/sporadic cases (hazard ratio, HR 1.30, 95% CI: 1.11-1.52) and worse BCSS than sporadic/BRCA-negative cases among patients with stage I-III breast cancer (HR 1.45, 95% CI: 1.01-2.07). BRCA2 mutation carriers have worse BCSS than sporadic/BRCA-negative cases (HR 1.29, 95% CI: 1.03-1.62), although they have similar OS. Among triple negative breast cancer, BRCA1/2 mutations carriers had better OS than BRCA-negative counterpart (HR 0.49, 95% CI: 0.26-0.92). Among Ashkenazi Jewish women, BRCA1/2 mutations carriers presented higher risk of death from breast cancer (HR 1.44, 95% CI: 1.05-1.97) and of distant metastases (HR 1.82, 95% CI: 1.05-3.16) than sporadic/BRCA-negative patients.

CONCLUSION

Our results support the evaluation of BRCA mutational status in patients with high risk of harboring BRCA germline mutations to better define the prognosis of breast cancer in these patients.

Prevalence and Prognostic Role of BRCA1/2 Variants in Unselected Chinese Breast Cancer Patients

Background

The prevalence of BRCA1/2 variants in Chinese breast cancer patients varies among studies. Germline or somatic BRCA1/2 mutations are associated with sensitivity to poly(ADP-ribose) polymerase-1 inhibitors and DNA-damaging agents. We aimed to investigate the distribution of both somatic and germline BRCA1/2 variants in unselected Chinese breast cancer patients, and explore their roles in tumor phenotype and disease prognosis.

Methods

507 breast cancer patients, unselected for family history of breast cancer or age at diagnosis, were prospectively enrolled from West China Hospital between Feb. 2008 and Feb. 2014. BRCA1/2 variants in the exons/flanking regions were detected in fresh-frozen tumors using next-generation sequencing and confirmed by independent methods. Germline/somatic status was validated by Sanger sequencing in paired blood/normal tissue.

Results

BRCA1/2 pathogenic or likely pathogenic (P/LP) variants were detected in 50 patients (9.9%), including 40 germline carriers (18 in BRCA1, 22 in BRCA2), 9 patients with somatic variants (3 in BRCA1, 6 in BRCA2), and 1 patient with concurrent germline/somatic variants in BRCA2. The triple-negative (21.4%) and Luminal B (9.7%) subtypes had higher rates of BRCA1/2 variants. In patients with disease stage 0~II, presence of a germline or somatic BRCA1 P/LP variant increased the risk of relapse as compared to non-carriers [univariate hazard ratio (HR): 3.70, P = 0.04]. Germline BRCA1 P/LP variants, which were associated with aggressive tumor phenotypes, predicted worse disease-free survival in the subgroup of stage 0~II (HR: 4.52, P = 0.02) and N0 (HR: 5.4, P = 0.04) compared to non-carriers.

Conclusion

A high frequency of germline and somatic BRCA1/2 P/LP variants was detected in unselected Chinese breast cancer patients. Luminal B subtype should be considered as a high-risk population of BRCA1/2 mutation, in addition to triple-negative breast cancer. BRCA1 status was associated with aggressive tumor phenotype and worse disease progression in early stage breast cancer patients.

Her2-neu score as a prognostic factor for outcome in patients with triple-negative breast cancer

PURPOSE

Triple-negative breast cancer (TNBC) is characterized by a strong heterogeneity with regard to tumour biology as well as in the clinical course of the disease. This study aimed to analyse whether there are any prognostic factors enabling prediction of the clinical outcome in patients with TNBC. Particularly, the impact of Her2-neu score 0 versus Her2-neu score 1 and 2 on survival was investigated.

MATERIALS AND METHODS

We retrospectively studied a cohort of 1013 patients with TNBC, diagnosed at seven hospitals between May 2002 and February 2015. We studied the impact of Her2-neu scores (0 vs. 1 or 2 with negative FISH) on disease-free survival (DFS) and overall survival (OS).

RESULTS

1013 patients were included in this study. 447 (44.13 %) of them had a T2-4 tumour. A total of 314 (31.00 %) were nodal-positive and 714 (70.48 %) had high-grade tumours. The Her2-neu score of all participating patients was determined. 588 (58.05 %) of them had a Her2-neu score 0, and 425 (41.95 %) had a score of 1 or 2. This study shows that TNBC patients with a Her2-neu score 0 had a significantly poorer outcome regarding DFS (p = 0.0001) and OS (p = 0.0051) compared to a score of 1 or 2. In contrast, grading did not seem to have any prognostic value for women with TNBC.

CONCLUSION

The Her2-neu score 0 might be considered as an innovative prognostic factor for patients with TNBC indicating poor clinical outcome.

Integrating mutation and gene expression cross-sectional data to infer cancer progression

Background

A major problem in identifying the best therapeutic targets for cancer is the molecular heterogeneity of the disease. Cancer is often caused by an accumulation of mutations which produce irreversible damage to the cell’s control mechanisms of survival and proliferation. Different mutations may affect these cellular anachronisms through a combination of molecular interactions which may be dynamically changing during cancer progression. It has been previously shown that cancer accumulates mutations over time. In this paper we address the problem of cancer heterogeneity by modeling cancer progression using somatic mutation and gene expression cross-sectional data.

Results

We propose a novel formulation of integrating somatic mutation and gene expression data to infer the temporal sequence of events from cross-sectional data. Using a mixed integer linear program we model the interaction between groups of different mutated genes and the resulting modifications at the gene expression level. Our approach identifies a partition of mutation events which gradually produce gene expression changes to a partition of genes over time. The proposed formulation is tested using both simulated data and real breast cancer data with matched somatic mutations and gene expression measurements from The Cancer Genome Atlas. First, we classify the genes as oncogenes or tumor suppressors based on the frequency of driver mutations. As expected, the most frequently mutated genes in breast cancer are PIK3CA and TP53 genes. Then, we select those genes with most frequent driver mutations and a set of genes known to play roles in cancer development. Furthermore, we apply the proposed mixed integer linear program to identify the temporal order in which genes mutate and, simultaneously, the changes they produce at the gene expression level during cancer progression. In addition, we are able to identify known causal relationships between mutations and gene expression changes in PI3K/AKT and TP53 pathways.

Conclusions

This paper proposes a new model to infer the temporal sequence in which mutations occur and lead to changes at the gene expression level during cancer progression. The approach is general and can be applied to any data sets with available somatic mutations and gene expression measurements.

Electronic supplementary material

The online version of this article (doi:10.1186/s12918-016-0255-6) contains supplementary material, which is available to authorized users.

Increased ID4 expression, accompanied by mutant p53 accumulation and loss of BRCA1/2 proteins in triple-negative breast cancer, adversely affects survival

AIMS

Breast cancer 1 (BRCA1) expression is down-regulated in a significant proportion of non-hereditary breast cancers, in the absence of any mutation. This phenomenon is more pronounced in oestrogen (ER)-negative tumours. Recent studies have suggested that inhibitor of DNA binding 4 (ID4), as well as p53, participate in the transcriptional regulation of BRCA1.

METHODS

Immunohistochemical expression of ID4, BRCA1, BRCA2 and p53 in 699 women with triple-negative breast cancer was investigated using tissue microarrays. The prognostic role of these biomarkers was also evaluated. Survival outcomes were estimated with the Kaplan-Meier method and compared between groups with log-rank statistics.

RESULTS

Loss of BRCA1 and BRCA2 expression and overexpression of ID4 and p53 was observed in 75%, 90%, 95% and 66% of tumours, respectively. ID4 expression was increased in higher tumour grade (P < 0.001) and was associated significantly with basal-like subtype (P < 0.001), BRCA2 down-regulation (P = 0.037) and p53 accumulation (P < 0.001). Patients with strong ID4 expression displayed worse disease-free survival in both triple-negative breast cancers (P = 0.041) and basal-like triple-negative breast cancers (P = 0.026).

CONCLUSION

There is frequent ID4 expression and concomitant loss of BRCA proteins in triple-negative breast cancer. We hypothesize that strong ID4 expression could be useful as a prognostic marker in triple-negative breast cancer, predicting early tumour recurrence.

High expression of miR-214 is associated with a worse disease-specific survival of the triple-negative breast cancer patients

Background

Hereditary triple-negative breast cancer patients have better recurrence-free survival than triple-negative sporadic ones. High expression of some of the miRNAs is related to worse overall and disease-free survival of triple-negative breast cancer patients. The attempt to associate expression level of some miRNA in triple-negative hereditary and sporadic breast cancers to disease specific survival was performed in this study.

Material and methods

Study group was made of 18 triple-negative breast cancer patients harboring the BRCA1 gene mutations and 32 triple-negative sporadic breast cancer patients. Quantitative amount of mir-10b, mir-21, mir-29a, mir-31, and mir-214 by real-time PCR was assessed. The disease-specific survival in relation of high and low levels of some of the miRNAs was analyzed using Log-rank (Mantel-Cox) test.

Results

MiR-214 showed significantly higher expression level in sporadic tissues than in hereditary ones (p = 0.0005). Triple-negative breast cancer patients with high level of miR-214 showed significantly worse disease-specific survival than patients with low level (p = 0.0314).

Conclusions

Our finding suggests that miR-214 possibly could be used as a potential prognostic biomarker for triple-negative breast cancer patients.

Electronic supplementary material

The online version of this article (doi:10.1186/s13053-015-0028-z) contains supplementary material, which is available to authorized users.

Prevalence of BRCA1 mutations and responses to neoadjuvant chemotherapy among BRCA1 carriers and non-carriers with triple-negative breast cancer

BACKGROUND

The frequency of BRCA1 germline mutations among Chinese women with triple-negative breast cancer is unclear, and the association between BRCA1 mutations and the response to neoadjuvant chemotherapy in women with triple-negative breast cancer has not been determined.

PATIENTS AND METHODS

Nine hundred and fifty-six triple-negative breast cancer patients were treated at our institute between 2003 and 2012; we tested the BRCA1/2 mutations for 956 patients and 953 patients in this cohort, respectively. Among the 956 patients, 652 patients received neoadjuvant chemotherapy.

RESULTS

In this cohort, 7.1% (68/956) and 2.3% (22/953) of patients carried a BRCA1 or BRCA2 mutation, respectively. The BRCA1/2 mutation rates were 10.5% and 3.0% among the patients who were diagnosed at or before the age of 50 in this cohort, respectively. The pCR (pathologic complete response) rate was 31.6% in the 652 patients who received neoadjuvant chemotherapy. BRCA1 carriers had a significantly higher pCR rate than non-carriers (BRCA1 carriers versus non-carriers, 53.8% versus 29.7%, P < 0.001). Among women treated with anthracycline with or without taxane regimens, the pCR rate was 57.1% for BRCA1 carriers, 29.0% for non-carriers (P < 0.001); among women treated with taxane regimens, the pCR rate was 40.0% for BRCA1 carriers, 32.9% for non-carriers (P = 0.73). At a median follow-up of 43 months, the recurrence-free survival was similar between BRCA1 carriers and non-carriers among the 947 patients of this study (adjusted hazard ratio = 0.92; 95% confidence interval: 0.45-1.90; P = 0.82).

CONCLUSIONS

Chinese women with triple-negative breast cancer who are diagnosed at or before age of 50 are candidates for BRCA1 genetic testing. Among triple-negative breast cancer patients, BRCA1 carriers are more likely to respond to neoadjuvant anthracycline-based regimens than are non-carriers.