Novel germline mutations and unclassified variants of BRCA1 and BRCA2 genes in Chinese women with familial breast/ovarian cancer.

BACKGROUND: Germline mutations in the BRCA1 and BRCA2 genes greatly increase a woman's risk of developing breast and/or ovarian cancer. The prevalence and distribution of such mutations differ across races/ethnicities. Several studies have investigated Chinese women with high-risk breast cancer, but the full spectrum of the mutations in these two genes remains unclear. METHODS: In this study, 133 unrelated Chinese women with familial breast/ovarian cancer living in Zhejiang, eastern China, were enrolled between the years 2008 and 2014. The complete coding regions and exon-intron boundaries of BRCA1 and BRCA2 were screened by PCR-sequencing assay. Haplotype analysis was performed to confirm BRCA1 and BRCA2 founder mutations. In silico predictions were performed to identify the non-synonymous amino acid changes that were likely to disrupt the functions of BRCA1 and BRCA2. RESULTS: A total of 23 deleterious mutations were detected in the two genes in 31 familial breast/ovarian cancer patients with a total mutation frequency of 23.3% (31/133). The highest frequency of 50.0% (8/16) was found in breast cancer patients with a history of ovarian cancer. The frequencies of BRCA1 and BRCA2 mutations were 13.5 % (18/133) and 9.8% (13/133), respectively. We identified five novel deleterious mutations (c.3295delC, c.3780_3781delAG, c.4063_4066delAATC, c.5161 > T and c.5173insA) in BRCA1 and seven (c.1-40delGA, c.4487delC, c.469_473delAAGTC, c.5495delC, c.6141T > A, c.6359C > G and c.7588C > T) in BRCA2, which accounted for 52.2% (12/23) of the total mutations. Six recurrent mutations were found, including four (c.3780_3781delAG, c.5154G > A, c.5468-1del8 and c.5470_5477del8) in BRCA1 and two (c.3109C > T and c.5682C > G) in BRCA2. Two recurrent BRCA1 mutations (c.5154G > A and c.5468-1del8) were identified as putative founder mutations. We also found 11 unclassified variants, and nine of these are novel. The possibility was that each of the non-synonymous amino acid changes would disrupt the function of BRCA1 and BRCA2 varied according to the different algorithms used. CONCLUSIONS: BRCA1 and BRCA2 mutations accounted for a considerable proportion of hereditary breast/ovarian cancer patients from eastern China and the spectrum of the mutations of these two genes exhibited some unique features. The two BRCA1 putative founder mutations may provide a cost-effective option to screen Chinese population, while founder effects of the two mutations should be investigated in a lager sample size of patients.

Lateral thoracic adipofascial flaps in the reconstruction of defects after breast-conserving surgery in breasts with ptosis mild ptosis or without ptosis.

OBJECTIVE: To study the feasibility, safety, and effectiveness of lateral thoracic adipofascial flaps in reconstructing the defects following breast-conserving surgery (BCS) in breasts with either no ptosis or mild ptosis. METHODS: 37 female patients who underwent BCS and lateral thoracic adipofascial flap breast reconstruction between June 2020 and July 2022 were analysed. Surgery-related complications, intraoperative positive margin, local recurrence, and cosmetic outcome were assessed. RESULTS: Three local complications occurred in patients, all of which were cured by conservative treatment. Additionally, four patients had intraoperative positive margins. After a median follow-up period of 17.5 months, none of the patients showed local recurrence. All patients achieved a satisfactory breast shape. Further, patients without ptosis achieved good volume and symmetry. However, the breast symmetry was not satisfactory for patients with ptosis. CONCLUSION: It is reliable and effective to use the lateral thoracic adipofascial flaps to reconstruct the defects after BCS when the breast is not ptotic and the lesions are located in the lateral and central quadrants.

Impact of Nischarin on EMT regulators in breast cancer cell lines.

Nischarin is an integrin-binding protein, which is well known as a novel tumor suppressor. In breast cancer, Nischarin serves a critical role in breast cancer cell migration and invasion. However, the molecular mechanism underlying the role of Nischarin remains unclear. Recent findings have demonstrated that epithelial-mesenchymal transition (EMT) increases the capacity of cell migration and invasion. As a member of the integrin family, it was hypothesized that Nischarin may regulate cellular processes via various signaling pathways associated with the EMT process. The present study detected the mRNA levels of EMT regulators via reverse transcription-quantitative PCR and related protein levels via western blotting in breast cancer cells, following NISCH-overexpression and -knockdown. The results demonstrated that Nischarin inhibits cell proliferation, migration and invasion in breast cancer cells. Furthermore, when the NISCH gene was overexpressed, the relative mRNA level of E-cadherin was increased, while the relative mRNA levels of several transcription factors, such as Snail, ZEB1, N-cadherin, Slug, Twist1 and vimentin, decreased. When NISCH was silenced, these results were reversed. The present results demonstrated that Nischarin suppresses cell migration and invasion via inhibiting the EMT process.

The genomic mutation spectrums of breast fibroadenomas in Chinese population by whole exome sequencing analysis.

Fibroadenomas (FAs) are the most common fibroepithelial lesions and the most common benign tumors of the breast in women of reproductive age. Although MED12 mutations, an overwhelming majority of all mutations, and some other gene mutations have been found in FAs, the genomic landscapes of FAs are still not completely clear and the genomic mutation spectrums of FAs in Chinese population remains unknown. Here, by performing whole exome sequencing of 12 FAs and the corresponding normal breast tissues in Chinese Han population, we observed the somatic and germline landscapes of genetic alterations. We identified 16 recurrently mutated genes with 37 nonsynonymous or frameshift somatic mutations and 27 recurrent somatic copy number variants (CNVs). In these mutated genes, MED12 was the most common in FAs, harboring 6 nonsynonymous/frameshift somatic mutations and 1 CNV. In addition, 6 germline mutations of tumor susceptibility genes in 5 FAs were identified and the tumor mutational burden of the 5 FAs was significantly higher than the other 7 FAs without germline mutations. This study provides genomic mutation spectrums of FAs in Chinese population and expand the genetic spectrum of FAs.

Expression of integrin-binding protein Nischarin in metastatic breast cancer.

The present study aimed to investigate the expression of Nischarin protein in primary breast cancer (PBC), and to evaluate its role in tumor metastasis. Paired specimens of breast cancer tissues and adjacent normal tissues were surgically obtained from 60 patients with PBC at the Zhejiang Cancer Hospital (Hangzhou, China). Nischarin protein concentrations were determined by an ELISA assay. Breast cancer tissues exhibited a significantly lower concentration of Nischarin (5.86 ± 3.19 ng/ml) compared with that of the adjacent noncancerous tissues (9.25 ± 3.65 ng/ml; P<0.001). Furthermore, cancer tissue from patients with lymph node metastasis had significantly lower levels of Nischarin protein (4.69 ± 2.40 ng/ml) than those of patients without lymph node metastasis (7.04 ± 3.47 ng/ml; P=0.004). There was no significant difference in Nischarin protein expression levels between patients with grade I, II or III PBC (grade I, 5.44 ± 3.57 ng/ml; grade II, 6.42 ± 3.85 ng/ml and grade III, 5.10 ± 1.18 ng/ml; P=0.765). The significant differences in the expression of Nischarin between: i) Cancer tissue and noncancerous tissue and ii) patients with and without lymph node metastasis, suggested that Nischarin may have a significant role in tumor occurrence and metastasis of breast cancer. Nischarin expression may therefore be used as a marker to predict the invasiveness and metastasis of PBC.

Low expression of stathmin in tumor predicts high response to neoadjuvant chemotherapy with docetaxel-containing regimens in locally advanced breast cancer.

AIMS: We performed this retrospective study to evaluate the value of clinicopathological factors and a novel molecular marker stathmin in predicting treatment response to neoadjuvant chemotherapy (NCT) with docetaxel-containing regimens in patients with locally advanced breast cancer. METHODS: Fifty-four consecutive locally advanced patients receiving docetaxel-containing NCT between January 2006 and July 2010 in Zhejiang Cancer Hospital were included. The expression levels of estrogen receptor (ER), progesterone receptor (PgR), epidermal growth factor receptor-2 (HER-2), and p53 were detected by immunohistochemistry, while expression of stathmin mRNA was measured by Quanti-Gene assay. RESULTS: The overall clinical objective response (cOR) rate was 75.9% (41/54) in breast. A total of 34 patients (63.0%) experienced pathological OR (pOR), with pathological complete remission (pCR) rate of 20.4% (11/54) in breast and 16.7% (9/54) in both breast and axilla. In univariate analysis, there were associations of pOR in both breast and axilla with age (p=0.054), ER status (p=0.059), subtypes (p=0.062), p53 (p=0.030), and stathmin expression (three terciles) (p=0.039). Mean expression of stathmin in pOR group was 0.410, compared with that in no response group of 0.556 (p=0.051 by Student's t-test). Similarly, a lower expression of stathmin might represent a higher pCR rate (p=0.061). Moreover, the LOWESS smoothing plot showed the same trend, that is, that tumor with a lower level of stathmin expression had a higher probability of response to docetaxel-containing NCT. After multivariate adjustment, both ER and stathmin remained significant with hazard ratio of 4.58 (95% CI: 1.11-18.94, p=0.036) and 2.94 (95% CI: 1.26-6.86, p=0.012), respectively. CONCLUSIONS: In conclusion, ER and stathmin were independent predictive factors for NCT with docetaxel-containing regimens.

Unilateral hemilaminectomy for patients with intradural extramedullary tumors.

A modified hemilaminectomy was introduced in an attempt to explore the operative techniques and the values of the limited approach to spinal cord tumors. Forty-five consecutive patients with intradural extramedullary lesions, who underwent modified hemilaminectomy, were studied retrospectively. The intraspinal tumors were removed via the limited bone window with a 3.3-cm mean length (range: 2.0-6.5 cm) and a 1.2-cm mean width (range: 0.6-1.5 cm), in which the inner parts of the medial and lateral laminae were mostly undercut for wider view. Spinal lesions were cervical in 21 cases, thoracic in 12 cases, lumbar in 10 cases, and multiple in 2 cases. Forty-three cases were completely excised via hemilaminectomy alone. Two subjects with dumbbell neurinoma underwent two-stage tumor removal via anterolateral cervical approach following hemilaminectomy. With respect to neurological status, the percentage of good Frankel scale (D+E grade) was markedly improved from 22.2% on admission to 93.3% at follow-up. At the median 26-month follow-up evaluation by magnetic resonance imaging (MRI), none of the subjects showed spinal deformity or instability. By preserving musculoligamentous attachments and posterior bony elements as much as possible, the modified approach is minimally invasive and may be routinely used to remove intradural and extramedullary tumors, especially in patients with meningiomas and neurinomas.