Characteristics of Chinese breast cancer patients with double heterozygosity for BRCA1 and BRCA2 germline pathogenic variants.

PURPOSE: Despite of very rare, breast cancer patients with double heterozygosity (DH) variants in BRCA1 and BRCA2 genes have been identified in other ethnic groups and seem to be associated with distinctive phenotypes. However, little is known about the frequency and clinical characteristics of Chinese breast cancer patients with BRCA1/2 DH variants. METHODS: Four hundred and eleven unrelated patients with BRCA1 or BRCA2 pathogenic variants (PVs) were identified in a large series of unselected breast cancer patients. Another two siblings with metachronous bilateral breast cancer were referred for genetic counseling, after which BRCA1/2 DH variants were detected. RESULTS: Four unrelated breast cancer patients with BRCA1/2 DH were identified in the cohort of 411 patients with BRCA1 or BRCA2 PVs, the frequency of BRCA1/2 DH was 0.97%. In total, six BRCA1/2 DH patients from five families were found in this study. In two families, the hereditary pattern of DH was speculated to have originated from both sides of the family. BRCA1/2 DH patients were more likely to have a family history of breast cancer than patients with a BRCA1 (100% vs. 29.2%, P = 0.004) or BRCA2 (100% vs. 29.6%, P = 0.004) single PV. BRCA1/2 DH patients were more likely to be triple-negative breast tumors than patients with single BRCA2 PVs (66.7% vs. 14.1%, P = 0.020), which was comparable to the findings in patients with single BRCA1 PVs (66.7% vs. 56.9%, P = 1.00). CONCLUSION: Chinese patients with BRCA1/2 DH exhibit a high percentage of family history of breast cancer. The tumor pathological features of BRCA1/2 DH carriers are similar to those of BRCA1 PV carriers.

KLHL22 activates amino-acid-dependent mTORC1 signalling to promote tumorigenesis and ageing.

The mechanistic target of rapamycin complex 1 (mTORC1) is a master regulator of cell growth that responds to a diverse set of environmental cues, including amino acids1,2. Deregulation of mTORC1 has been linked with metabolic diseases, cancer and ageing2-4. In response to amino acids, mTORC1 is recruited by the Rag GTPases to the lysosome, its site of activation5,6. The GATOR1 complex, consisting of DEPDC5, NPRL3 and NPRL2, displays GAP activity to inactivate Rag GTPases under amino-acid-deficient conditions 7 . However, it is unclear how the inhibitory function of GATOR1 is released upon amino acid stimulation. Here we find that in response to amino acids, the CUL3-KLHL22 E3 ubiquitin ligase promotes K48-linked polyubiquitination and degradation of DEPDC5, an essential subunit of GATOR1. KLHL22 plays a conserved role to mediate the activation of mTORC1 and downstream events in mammals and nematodes. Depletion of MEL-26, the Caenorhabditis elegans orthologue of KLHL22, extends worm lifespan. Moreover, KLHL22 levels are elevated in tumours of breast cancer patients, whereas DEPDC5 levels are correspondingly reduced. Depletion of KLHL22 in breast cancer cells suppresses tumour growth in nude mice. Therefore, pharmacological interventions targeting KLHL22 may have therapeutic potential for the treatment of breast cancer and age-related diseases.

Impact of multifocal or multicentric disease on local recurrence and survival in breast cancer patients with or without BRCA1/2 variants.

PURPOSE: Multifocal or multicentric (MFMC) breast cancer is mainly focused on breast cancer patients with unknown BRCA status, the incidence and clinical relevance of MFMC disease in BRCA1/2 carriers is less explored to date. Our study was to investigate the incidence of MFMC disease in BRCA1/2 carriers and whether MFMC disease influences local recurrence and clinical outcomes. METHODS: In this retrospective study, 479 breast cancer patients with BRCA1/2 variants and 1437 age-matched noncarriers were enrolled and patients received either breast-conserving therapy (BCT) or mastectomy with or without radiotherapy. RESULTS: The rates of MFMC disease in BRCA1 and BRCA2 carriers, and noncarriers were 33.0% (61 of 185), 37.4% (110 of 294), and 31.2% (449 of 1437), respectively. MFMC disease in BRCA2 carriers was significantly higher than that in noncarriers (P = 0.039). After a median follow-up of 8.1 years, among patients treated with BCT, BRCA2 carriers with MFMC disease experienced a significantly higher rate of ipsilateral breast tumor recurrence (IBTR) than those with unifocal disease (16.7% vs 4.1%, P = 0.044). Moreover, BRCA2 carriers with MFMC disease had a significantly worse RFS (unadjusted hazard ratio [HR], 3.65 [95% CI 1.40-9.52]; P = 0.008), DRFS (unadjusted HR, 3.07 [95% CI 1.07-8.80]; P = 0.037), and OS (unadjusted HR, 4.96 [95% CI 1.18-20.02]; P = 0.029) than those with unifocal disease when treated with BCT. CONCLUSION: MFMC breast cancer is more common in BRCA2 carriers, and BRCA2 carriers with MFMC disease treated with BCT exhibit a higher rate of IBTR and may have a poor survival.

Prevalence of BRCA1 and BRCA2 pathogenic variants in 8627 unselected patients with breast cancer: stratification of age at diagnosis, family history and molecular subtype.

PURPOSE: Comprehensively analyzing the prevalence of BRCA1/2 germline pathogenic variants (PVs) in a large cohort of unselected Chinese patients with breast cancer has great clinical importance. METHODS: Germline pathogenic variants in full-length BRCA1/2 genes were determined through next-generation sequencing and/or Sanger sequencing assays in 8627 unselected Chinese patients with breast cancer who were treated at the Breast Center of Peking University Cancer Hospital. The prevalence of BRCA1/2 PVs was further stratified by age at diagnosis, family history of cancer and molecular subtype. RESULTS: We found that the overall prevalence of BRCA1/2 PVs was 6.0% in the entire cohort, 2.4% in BRCA1 and 3.7% in BRCA2. The prevalence of BRCA1/2 PVs in patients with early-onset breast cancer (age at diagnosis ≤ 40 years) was significantly higher than that in patients over the age of 40 (9.7% vs. 5.1%). The prevalence rates of BRCA1/2 PVs in patients with a family history of breast, ovarian, pancreatic, and prostate cancer were 19.5%, 39.0%, 11.1%, and 12.8%, respectively. Moreover, the number of relatives affected by breast cancer was associated with a higher prevalence of BRCA1/2 PVs. Molecular subtypes were associated with the prevalence of BRCA1/2 PVs. Patients with the triple-negative phenotype had the highest prevalence of BRCA1/2 PVs (13.3%) among the three molecular groups, followed by the HR + and HER2- group (5.9%), and the lowest was in the HER2 + group (2.5%). CONCLUSION: Our study provides the most comprehensive information to date on the prevalence of BRCA1/2 PVs in unselected Chinese patients with breast cancer.

Neoadjuvant endocrine therapy for strongly hormone receptor-positive and HER2-negative early breast cancer: results of a prospective multi-center study.

PURPOSE: For estrogen receptor (ER)-positive breast cancer, neoadjuvant endocrine therapy (NET) has been shown to be as effective as neoadjuvant chemotherapy (NACT). We evaluated the prognostic significance of Preoperative Endocrine Prognostic Index (PEPI). METHODS: We conducted a prospective, multi-center, non-randomized, controlled trial that enrolled postmenopausal early-stage strongly ER-positive (≥ 50%) and HER2-negative breast cancer patients. All patients were given 4-month NET before surgery. The primary objective was to investigate the 5-year recurrence-free survival (RFS) in patients who had PEPI 0-1 or pathological complete response (pCR) without chemotherapy. Patients who had PEPI 0-1 or pCR were recommended to receive adjuvant endocrine therapy only and patients had PEPI ≥ 2 may receive adjuvant chemotherapy at the discretion of the treating physician. RESULTS: A total of 410 patients were included and 352 patients constituted the per-protocol population. Overall, 9 patients (2.5%) had pCR (ypT0/is ypN0), 128 patients (36.4%) had PEPI = 0, and 56 patients (15.9%) had PEPI = 1. After a median follow-up of 60 months (4-104 months), patients who had PEPI 0-1 or pCR showed an improved 5-year RFS [99.5% (95% CI 98.5-99.9%) for PEPI 0-1 or pCR group vs. 93.7% (95% CI 89.6-97.8%) for PEPI ≥ 2 group, P = 0.028]. No survival difference was detected between patients received adjuvant chemotherapy vs. no chemotherapy among PEPI ≥ 2 cases. CONCLUSION: PEPI 0-1 or pCR may be used to define a group of ER-positive and HER2-negative postmenopausal early breast cancer patients with low relapse risk for whom adjuvant chemotherapy can be safely withheld. Studies on the identification and alternative treatment options for endocrine-resistant tumors are warranted. CLINICAL TRIAL REGISTRATION: NCT01613560.

Ovarian cancer risk of Chinese women with BRCA1/2 germline pathogenic variants.

Estimating the lifetime risk of ovarian cancer in Chinese women with BRCA1/2 germline pathogenic variants (PVs) is of great importance for the clinical management of BRCA1/2 carriers. This cohort study recruited 9903 unselected Chinese breast cancer patients whose BRCA1/2 status was determined. Of these, 3984 probands completed family history questionnaires, which investigated the health status of their relatives, including 11,997 female first-degree relatives. The ovarian cancer risk of BRCA1/2 germline pathogenic carriers was estimated using the ovarian cancer history of proband first-degree female relatives via the Kin-cohort method. Of the 3984 probands, 126 (3.2%) carried BRCA1 PVs, and 183 (4.6%) carried BRCA2 PVs. The estimated cumulative risks of ovarian cancer by age 70 were 15.3% (95% CI 8.4-18.6%) for BRCA1 carriers, 5.5% (95% CI 2.0-10.2%) for BRCA2 carriers, and 0.4% (95% CI 0.3-0.7%) for noncarriers. The cumulative risks of ovarian cancer were very low before the age of 40 for both BRCA1 and BRCA2 carriers and were an increase up to age 45. The cumulative ovarian cancer risk of BRCA1 carriers was approximately three times higher than that of BRCA2 carriers, and BRCA1 and BRCA2 carriers had 38- and 14-fold higher risks than non-BRCA carriers, respectively. The findings indicate that Chinese women with BRCA1/2 PVs have high risks of ovarian cancer in their lifetime, especially BRCA1 carriers. These results are useful for devising optimal strategies to reduce ovarian cancer risk in BRCA1/2 carriers.

Predictors of sentinel lymph node metastasis in Chinese women with clinical T1-T2 N0 breast cancer and a normal axillary ultrasound.

BACKGROUND: The clinicopathological predictors of sentinel lymph node (SLN) metastasis in clinical T1-T2 N0 (cT1-T2 N0) patients with a normal axillary ultrasound (AUS) are unclear. PURPOSE: To assess the association between clinicopathological characteristics of a primary tumor and SLN metastasis in cT1-T2 N0 patients with a normal AUS. MATERIAL AND METHODS: Patients who were diagnosed with cT1-T2 N0 invasive breast cancer and who obtained normal AUS results between October 2016 and September 2018 in a single hospital were included. Clinicopathological data were collected to explore the predictors of SLN metastasis using a multivariate logistic regression model. RESULTS: SLN metastasis occurred in 26 patients (18.4%) among 141 AUS-normal patients, of which 24 cases (17.0%) had one or two nodal involvements. In the univariate analysis, tumor location, estrogen receptor (ER) status, progesterone receptor (PR) status, and lymphovascular invasion (LVI) were significantly associated with SLN metastasis (P < 0.05). The multivariate analysis showed that tumor location in the upper outer quadrant (odds ratio [OR] = 4.49, 95% confidence interval [CI] = 1.63-12.37; P = 0.004), positive PR status (OR = 13.35, 95% CI = 1.60-111.39; P = 0.017), and positive LVI (OR = 8.66, 95% CI = 2.20-34.18; P = 0.002) were independent high-risk factors for SLN metastasis. The area under the receiver operating characteristic curve of the regression model was 0.787 (95% CI = 0.694-0.881; P < 0.001). CONCLUSION: Tumor location in the upper outer quadrant, positive PR, and LVI status were found to be significantly high-risk factors for SLN metastasis among cT1-T2 N0 breast cancer patients with a normal AUS result.

Impact of the addition of carboplatin to anthracycline-taxane-based neoadjuvant chemotherapy on survival in BRCA1/2-mutated triple-negative breast cancer.

Whether adding carboplatin to standard neoadjuvant chemotherapy improves survival in BRCA1/2-mutated triple-negative breast cancer (TNBC) is unknown. In this retrospective study, we aimed to explore the efficacy of anthracycline-taxane (A-T)-based or anthracycline-taxane/carboplatin (A-TP)-based neoadjuvant chemotherapy in BRCA1/2-mutated TNBC. A total of 1585 operable primary breast cancer patients were treated with either neoadjuvant A-T (n = 886) or A-TP regimen (n = 699). BRCA1 and BRCA2 germline mutations were determined in all subjects. Pathological complete response (pCR), recurrence-free survival (RFS), distant recurrence-free survival (DRFS) and overall survival (OS) were estimated. Of the entire cohort, 102 patients (6.4%) carried a pathogenic BRCA1/2 germline mutation. After a median follow-up of 81 months, no significant differences in survival between the A-T and A-TP arms were found in the entire cohort. However, among 288 TNBC patients, BRCA1/2 mutation carriers had significantly better survival when treated with the A-TP regimen than with the A-T regimen (5-year RFS: 82.6% vs 47.9%; P = .024; 5-year DRFS: 88.5% vs 46.9%; P = .010; 5-year OS: 88.2% vs 49.9%; P = .036). Multivariate analyses revealed that the A-TP regimen was a significantly favourable factor for RFS and DRFS and showed a trend towards better OS when compared with the A-T regimen in BRCA1/2-mutated TNBC (RFS: adjusted hazard ratio [HR], 0.24; 95% confidence interval [CI], 0.06-0.91, P = .035; DRFS: HR, 0.17; 95% CI, 0.03-0.80; P = .025; OS: HR, 0.29; 95% CI, 0.06-1.49; P = .14). Our study suggested that BRCA1/2-mutated TNBC patients gain a survival benefit when carboplatin is added to standard A-T-based neoadjuvant chemotherapy.

Contralateral breast cancer risk in BRCA1 and BRCA2 mutation carriers in a large cohort of unselected Chinese breast cancer patients.

To estimate the cumulative risk of contralateral breast cancer (CBC) in BRCA1/2 carriers in a large cohort of unselected Chinese breast cancer patients. Our study comprised 9,401 unselected Chinese breast cancer patients and BRCA1/2 germline mutations were determined in all patients. After a median follow-up of 5.7 years, 181 patients developed CBC in this cohort. Compared to noncarriers, BRCA1 and BRCA2 carriers had a 4.52-fold (95% CI, 2.63-7.76) and 5.54-fold (95% CI, 3.51-8.74) increased risk of CBC, respectively. The 10-year cumulative risk of CBC was 15.5% (95% CI, 9.9-24.2) for BRCA1 carriers, 17.5% (95% CI, 10.9-28.0) for BRCA2 carriers and 3.2% (95% CI, 2.5-4.1) for noncarriers. Younger age at first breast cancer diagnosis was significantly associated with an increased 10-year risk of CBC for BRCA1 carriers (≤40 years vs. >40 years: 21.5% vs. 11.9%, unadjusted hazard ratio [HR] = 2.51, 95% CI, 1.03-6.15, p = 0.044), but not for BRCA2 carriers and noncarriers. The 10-year cumulative CBC risk was significantly higher in both BRCA1 and BRCA2 carriers who had a family history of breast cancer than in those who did not (BRCA1: 27.5% vs. 9.4%, adjusted HR = 2.64, 95% CI, 1.01-6.97, p = 0.049; BRCA2: 27.1% vs. 12.8%, adjusted HR = 2.29, 95% CI, 1.04-5.06, p = 0.040). In conclusion, the risk of CBC was a substantial high in BRCA1/2 carriers in unselected Chinese breast cancer patients, and CBC risk is much more remarkable in both BRCA1 and BRCA2 carriers who had a family history of breast cancer. Younger age at first breast cancer diagnosis also enhanced CBC risk in BRCA1 carriers.

BRCA1 c.5470_5477del, a founder mutation in Chinese Han breast cancer patients.

The spectrum and frequency of BRCA1/2 pathogenic variants may be ethnicity-specific. Whether high-frequency founder mutations are present in Chinese women remains largely unknown. In the current study, germline pathogenic variants in the BRCA1/2 genes were determined in 9,505 unselected Chinese Han breast cancer (BC) patients by next-generation and/ or Sanger sequencing. Four hundred and seventy-one (5.0%) BC patients carried BRCA1/2 pathogenic variants in this cohort. A total of 25 recurrent pathogenic variants (at least found in four unrelated patients) were identified in this cohort (8 BRCA1 and 17 BRCA2 recurrent pathogenic variants), 161 patients carried one of these recurrent pathogenic variants in this cohort of 9,505 patients. All of these 25 recurrent pathogenic variants were further explored whether they had founder effect through haplotype analysis. The most common pathogenic variant, BRCA1 c.5470_5477del, was found in 30 BC patients from 29 unrelated families. Twenty-seven of these 29 unrelated patients who carried this BRCA1 c.5470_5477del mutation shared an identical haplotype, indicating that BRCA1 c.5470_5477del was a founder mutation in the Chinese Han population. Furthermore, BRCA1 c.5470_5477del mutation carriers had a significantly worse survival than noncarriers (disease-free survival, p = 0.049; overall survival, p = 0.029). Taken together, our data suggested that BRCA1 c.5470_5477del is a founder mutation in the Chinese Han population and BRCA1 c.5470_5477del mutation carriers have a poor survival.

Prevalence and clinical impact of TP53 germline mutations in Chinese women with breast cancer.

The prevalence and clinical relevance of TP53 germline mutations in a large unselected breast cancer series are largely unknown. Here, we determined TP53 germline mutations in a large cohort of 10,053 unselected breast cancer patients through multigene panel-based next-generation and/or Sanger sequencing assays. We found that 0.5% of patients (50 cases) carried a pathogenic TP53 germline mutation in this large series of 10,053 unselected breast cancer patients, and the prevalence of TP53 germline mutation was 3.8% in very early onset breast cancer (age ≤30 years) in this large cohort. TP53 mutation carriers were significantly more likely to have early onset cancer (p < 0.001) and bilateral breast cancer (p = 0.03), they and were significantly more likely to respond to carboplatin-based neoadjuvant chemotherapy compared to anthracycline- or taxane-based regimen in terms of pathologic complete response (50% vs. 0%, p = 0.006). At the median follow-up of 54 months, TP53 mutation was an independent unfavorable factor for recurrence-free survival (RFS), distant recurrence-free survival (DRFS), and overall survival (OS) (RFS, adjusted hazard ratio [HR]: 2.24, 95% confidence interval [CI]: 1.15-4.33, p = 0.02; DRFS, adjusted HR: 2.73, 95% CI: 1.41-5.30, p = 0.003; OS, adjusted HR: 4.60, 95% CI: 2.26-9.41, p < 0.001) in multivariate analyses. Our study suggested that TP53 germline mutations occur more frequently in very early onset unselected breast cancer patients; and TP53 germline mutation carriers have a very poor survival and may benefit from carboplatin-based neoadjuvant chemotherapy in unselected breast cancer patients.

Comparisons of breast conserving therapy versus mastectomy in young and old women with early-stage breast cancer: long-term results using propensity score adjustment method.

PURPOSE: This study aimed to compare the effect of BCT versus mastectomy on the recurrence and survival of different-aged patients, and to investigate whether effects of BCT versus mastectomy on survival of young patients were consistent with those of old patients. METHODS: Data on women with primary invasive breast cancer between 2007 and 2011 were extracted from the institutional database of Breast Center. Disparities in hormone receptor, tumor size, lymph node status, and Her-2 status between BCT and mastectomy groups were adjusted using the propensity score (PS) adjustment method. Patients were divided by age into two groups (≤ 40 years and > 40 years). We assessed proportions of local recurrence (LR), distant disease-free survival (DDFS), disease-free survival (DFS), and breast cancer-specific survival (BCSS) in different-aged groups; this assessment was further stratified by surgical treatment. RESULTS: A total of 2964 patients were included; 565 (19%) were aged ≤ 40 years. In the entire cohort, hazard ratios (HR) of BCT versus mastectomy for DDFS and DFS were 0.56 (P = 0.029) and 0.55 (P = 0.008), respectively. After PS adjustment, there was no significant difference between BCT and mastectomy in LR, DDFS, DFS and BCSS in the young age group. In the old age group, women who underwent BCT exhibited improved DDFS (HR 0.57, 95% CI 0.39-0.84, P = 0.004). CONCLUSIONS: BCT did not significantly affect survival outcomes of young patients with breast cancer. Superior survival of BCT compared to mastectomy was observed only in old patients.

Effect of functional variant rs11466313 on breast cancer susceptibility and TGFB1 promoter activity.

PURPOSE: This study aimed to investigate whether genetic polymorphisms in TGFB1 contribute to breast cancer (BC) susceptibility, and explore the mechanism of action. METHODS: A total of 7 tagging SNPs (tSNPs) were genotyped in 1161 BC cases and 1337 age-matched controls among Chinese Han population. Bioinformatics analysis was used to predict functional SNP closely linked to tSNPs. Luciferase gene reporter assay was performed to determine the effect of genetic variants on promoter activity. DNA pull-down assay and mass spectrometry were used to identify the differentially binding proteins to genetic variants. RESULTS: Genotyping analysis showed that rs1800469 (C>T) in the 5' regulatory region of TGFB1 was associated with reduced BC risk. Bioinformatics analysis predicted that rs11466313 (-2389_-2391 Del/AGG) in the 5' regulatory region of TGFB1, was closely linked to tSNP rs1800469 and could be functional. The genotyping of rs11466313 by PCR-SSCP showed that rs11466313 also conferred decreased BC risk. Luciferase assays demonstrated that rs11466313 minor allele reduced over ninefold of promoter activity compared with its major allele (p < 0.001). DNA pull-down assay and mass spectrometry revealed that rs11466313 minor allele lost the binding ability with FAM98B and HSP90B. Knocking down FAM98B but not HSP90B, the enhanced promoter activity driven by TGFB1 rs11466313 major allele was attenuated. CONCLUSIONS: This study elucidates the impact of functional polymorphism rs11466313 in the regulatory region of TGFB1 on breast cancer susceptibility and gene expression, and could be helpful for future research to determine the value of this TGFB1 variant in the clinical setting.

Spectrum and clinical relevance of PALB2 germline mutations in 7657 Chinese BRCA1/2-negative breast cancer patients.

PURPOSE: To investigate the prevalence and clinical relevance of PALB2 germline mutations in BRCA1/2-negative breast cancer patients. METHODS: The exons and intron-exon boundaries of the PALB2 gene were sequenced by multigene panel testing in a cohort of 7657 Chinese BRCA1/2-negative breast cancer patients. RESULTS: Of the 7657 patients, 54 (0.71%) carried pathogenic PALB2 germline mutations, all of which were nonsense or frameshift mutations leading to a truncated protein. The 54 patients carried 42 distinct pathogenic mutations, of which 17 (40.5%) were novel and 8 were recurrent mutations. Compared with non-carriers, PALB2 pathogenic mutation carriers developed breast cancer at a younger age (47.52 years vs. 51.35 years, p = 0.016) and were more likely to have triple-negative (24.1% vs. 13.4%, p = 0.022) or HER2 negative (87.0% vs. 74.2%, p = 0.031) breast cancer and large breast tumors (> 2 cm) at diagnosis (72.2% vs. 57.0%, p = 0.024). PALB2 mutation carriers were also more likely to have family histories of breast and/or ovarian cancer (27.8% vs. 8.4%, p < 0.001) and any types of cancer (57.4% vs. 31.6%, p < 0.001) when compared with non-carriers. CONCLUSIONS: PALB2 germline mutations are present at 0.71% in Chinese BRCA1/2-negative breast cancer patients and are more frequent in patients with triple-negative breast cancer and family histories of breast and/or ovarian cancer.

Germline mutation in DNA-repair genes is associated with poor survival in BRCA1/2-negative breast cancer patients.

BRCA1/2 genes are the most frequently germline mutated DNA-repair genes, and the survival of BRCA1/2 carriers has been extensively explored in breast cancer. However, the prevalence of germline mutations in non-BRCA1/2 DNA-repair genes and the survival of carriers are largely unknown in a large cohort of unselected breast cancer patients. Germline mutations in 16 DNA-repair genes were determined using a multigene panel in 7657 BRCA1/2-negative breast cancer patients who were unselected for family history of cancer or age at diagnosis. Among the 7657 BRCA1/2-negative breast cancer patients, 257 (3.4%) carried at least 1 pathogenic germline mutation in the 16 DNA-repair genes. The prevalence of DNA-repair gene mutations was significantly higher in familial breast cancers (5.2%, P = 0.002) and early-onset breast cancers (diagnosed at and before the age of 40) (4.5%, P = 0.003) than that of sporadic breast cancers (2.9%) (diagnosed above age of 40), respectively. The DNA-repair gene mutation carriers were significantly more likely to have a larger tumor (P = 0.04) and axillary lymph node metastasis (P = 0.03). Moreover, DNA-repair gene mutation was an independent unfavorable factor for recurrence-free survival (adjusted hazard ratio [HR] = 1.38, 95% CI: 1.00-1.91, P = 0.05) and disease-specific survival (adjusted HR=1.63, 95% CI: 1.04-2.57, P = 0.03) in this cohort. Overall, 3.4% of BRCA1/2-negative breast cancer patients carried germline mutations in the 16 DNA-repair genes, and the DNA-repair gene mutation carriers exhibited an aggressive phenotype and had poor survival compared with noncarriers.

Risk of ipsilateral breast tumor recurrence in primary invasive breast cancer following breast-conserving surgery with BRCA1 and BRCA2 mutation in China.

PURPOSE: BRCA1/2 germline mutations are associated with a high risk of breast cancer, which may preclude mutation carriers from breast-conserving surgery (BCS). This study retrospectively examined whether mutation status influenced the rate of ipsilateral breast tumor recurrence (IBTR) after BCS  in Chinese women. METHODS: Patients who underwent BCS were enrolled in carriers group and non-carriers group according to their BRCA1/2 mutation status in the study. The correlations were analyzed between IBTR incidence and BRCA1/2 mutation. The IBTR cases were further separated into new primary tumor (NP) and true local recurrences (TR). The risk factors of NP were studied in multivariate analysis. RESULTS: 1947 consecutive Chinese women with primary invasive breast cancer were selected. 103 patients were identified as BRCA1/2 mutation carriers and 1844 were non-carriers. BRCA1/2 mutation carriers were younger (P < 0.001) with more often negative HER-2 expression (P = 0.01) and tumor size over 2 cm (P = 0.04) than non-carriers. The median follow-up for all patients was 80 months. The rate of IBTR was 3.9% in mutated carriers and 2.0% in non-carriers, respectively (P = 0.16). In IBTR cases, NP incidence was 3.9% in carrier group and 0.6% in non-carrier group, respectively (P < 0.01). After adjustment of all clinical-pathological factors, BRCA1/2 mutation was the only statistical risk factor of NP incidence (HR = 6.29, P = 0.002), while positive lymph node was nearly statistically significant (HR = 2.70, P = 0.06). CONCLUSIONS: BCS may be a rational option for Chinese BRCA1/2 mutation carriers. High NP incidence in mutation carriers should be paid close attention in the future.

Prevalence and characterization of ATM germline mutations in Chinese BRCA1/2-negative breast cancer patients.

PURPOSE: The ataxia telangiectasia-mutated (ATM) gene is a moderate susceptibility gene for breast cancer. However, little is known about the breast cancer phenotypes associated with ATM mutation. We therefore investigated the spectrum and clinical characteristics of ATM germline mutations in Chinese breast cancer patients. METHODS: A multi-gene panel was performed to screen for ATM germline mutations in 7657 BRCA1/2-negative breast cancer patients. All deleterious mutations were validated by independent polymerase chain reaction (PCR)-Sanger sequencing. RESULTS: A total of 31 pathogenic mutations in the ATM gene across 30 carriers were identified, and the ATM mutation rate was 0.4% (30/7,657) in this cohort. The majority of the mutations (90.3%, 28/31) were nonsense or frameshift mutations. Of the total ATM mutations, 61.3% (19/31) were novel mutations and 13 recurrent mutations were found. ATM mutations carriers were significantly more likely to have a family history of breast and/or ovarian cancer (26.7% in carriers vs. 8.6% in non-carriers, p < 0.001), as well as a family history of any cancer (60.0% in carriers vs. 31.5% in non-carriers, p = 0.001). In addition, ATM mutations carriers were significantly more likely to have oestrogen receptor (ER)-positive (p = 0.011), progesterone receptor (PR)-positive (p = 0.040), and lymph node-positive breast cancer (p = 0.034). CONCLUSIONS: The prevalence of the ATM mutation is approximately 0.4% in Chinese BRCA1/2-negative breast cancer. ATM mutation carriers are significantly more likely to have a family history of cancer and to develop ER- and/or PR-positive breast cancer or lymph node-positive breast cancer.

Efficacy of pegfilgrastim to support neoadjuvant dose-dense epirubicin and cyclophosphamide chemotherapy in breast cancer.

PURPOSE: The role of long-acting hematopoietic growth factor in supporting dose-dense chemotherapy and minimizing hematologic toxicity has not been established. We investigated the efficacy and safety of once-per-cycle pegfilgrastim in breast cancer patients receiving neoadjuvant dose-dense epirubicin and cyclophosphamide (ddEC). METHODS: Newly diagnosed stage I to III breast cancer patients received four cycles of ddEC (E, 100 mg/m2 and C, 600 mg/m2 every 2 weeks) and 6 mg of subcutaneous pegfilgrastim on day 2 of each cycle. The primary endpoint was to evaluate the incidence of chemotherapy delay. Secondary endpoints include the incidences of febrile neutropenia (FN) and grade 3/4 neutropenia during the four ddEC cycles. RESULTS: A total of 240 patients were enrolled and 913 ddEC cycles were administered in the study. Chemotherapy delay occurred in 15 patients (6.3% of patients, 95% CI 3.2-9.4%) for 17 cycles (1.9% of cycles, 95% CI 1.0-2.8%). The most frequent cause of chemotherapy delay was transaminase elevation (10 patients, 12 cycles). A total of 12 patients (5.0%, 95% CI 2.2-7.8%) developed 13 episodes of FN. Of the 221 patients that completed four ddEC cycles with pegfilgrastim support, 209 patients (94.6%, 95% CI 91.6-97.6%) had a 100% relative dose intensity (RDI). A RDI ≥ 85% was achieved in 217 of 221 patients (98.2%, 95% CI 96.5-99.9%). Bone pain of any grade was recorded in 85 of 220 evaluable patients (38.6%, 95% CI 32.2-45.0%). CONCLUSIONS: Pegfilgrastim is effective and safe in facilitating four cycles of neoadjuvant ddEC, with low incidences of chemotherapy delay and febrile neutropenia.

RAD50 germline mutations are associated with poor survival in BRCA1/2-negative breast cancer patients.

RAD50 is a highly conserved DNA double-strand break (DSB) repair gene. However, the associations between RAD50 germline mutations and the survival and risk of breast cancer have not been fully elucidated. Here, we aimed to investigate the clinical impact of RAD50 germline mutations in a large cohort of unselected breast cancer patients. In our study, RAD50 germline mutations were determined using next-generation sequencing in 7657 consecutive unselected breast cancer patients without BRCA1/2 mutations. We also screened for RAD50 recurrent mutations (L719fs, K994fs, and H1269fs) in 5000 healthy controls using Sanger sequencing. We found that 26 out of 7,657 (0.34%) patients had RAD50 pathogenic mutations, and 16 patients carried one of the three recurrent mutations (L719fs, n = 6 cases; K994fs, n = 5 cases; and H1269fs, n = 5 cases); the recurrent mutation rate was 0.21%. The frequency of the three recurrent mutations in the 5,000 healthy controls was 0.18% (9/5,000). These mutations did not confer an increased risk of breast cancer in the studied patients [odds ratios (OR), 1.16; 95% confidence interval (CI), 0.51-2.63; p = 0.72]. Nevertheless, multivariate analysis revealed that RAD50 pathogenic mutations were an independent unfavourable predictor of recurrence-free survival (RFS) [adjusted hazard ratio (HR) 2.66; 95% CI, 1.18-5.98; p = 0.018] and disease-specific survival (DSS; adjusted HR 4.36; 95% CI, 1.58-12.03; p = 0.004) in the entire study cohort. Our study suggested that RAD50 germline mutations are not associated with an increased risk of breast cancer, but patients with RAD50 germline mutations have unfavourable survival compared to patients without these mutations.

Predictive value of BRCA1/2 mRNA expression for response to neoadjuvant chemotherapy in BRCA-negative breast cancers.

It is well known that BRCA1 and BRCA2 play a central role in DNA repair, but the relationship between BRCA1 and BRCA2 mRNA expression and response to neoadjuvant chemotherapy in sporadic breast cancer patients has not been well established. Here, we investigate the association between BRCA1 or BRCA2 mRNA expression levels and pathological response in 674 BRCA1/2 mutation-negative breast cancer patients who received neoadjuvant chemotherapy. BRCA1 and BRCA2 mRNA expression were assessed using quantitative real-time polymerase chain reaction in core biopsy breast cancer tissue obtained prior to the initiation of neoadjuvant chemotherapy. A total 129 patients (19.1%) achieved pathological complete response (pCR) after neoadjuvant chemotherapy. Among patients treated with anthracycline-based chemotherapy (n = 531), BRCA1 mRNA low expression patients had a significantly higher pCR rate than intermediate or high BRCA1 mRNA expression groups (24.6% vs 16.8% or 14.0%, P = .031) and retained borderline significance (OR = 1.54, 95% CI = 0.93-2.56, P = .094) in multivariate analysis. Among the 129 patients who received a taxane-based regimen, pCR rate showed no differences in BRCA1 low, intermediate, and high mRNA level subgroups (19.6%, 26.8% and 21.4%, respectively; P = .71). BRCA2 mRNA level was not associated with pCR rate in the anthracyline-based treated subgroup (P = .60) or the taxane-based regimen subgroup (P = .82). Taken together, our findings suggested that BRCA1 mRNA expression could be used as a predictive marker in BRCA1/2 mutation-negative breast cancer patients who received neoadjuvant anthracycline-based treatment.