Complexities in Adjuvant Endocrine Therapy for Breast Cancer in Female-to-Male Transgender Patients.

Introduction: Managing breast cancer in female-to-male (FtM) transgender patients is complicated and challenging. Androgens play a crucial role in the development of secondary sexual identity in FtM transgender patients, but their effectiveness in breast cancer remains unclear. Furthermore, the considerations for adjuvant endocrine therapy in this population are highly intricate and warrant thorough discussion. Case Presentation: We describe the case of a 44-year-old FtM transgender diagnosed with breast cancer 3 years after initiating androgen receptor agonist therapy as part of his gender identity transition. After mastectomy, adjuvant endocrine therapy was initiated, consisting of a combination of an aromatase inhibitor and a gonadotropin-releasing hormone agonist, along with a cross-sex hormone. Conclusion: Estradiol levels were significantly reduced, and male-typical levels of sex hormones were attained.

Acquired Treatment Resistance in a Patient with Metastatic PD-L1-Positive Breast Cancer and Germline BRCA1 Mutation.

Triple-negative breast cancer (TNBC) is an aggressive subtype of breast cancer associated with higher rates of relapse and mortality compared to other subtypes. Chemotherapy has been a mainstream treatment approach for TNBC due to the lack of therapeutic targets. Recent advances have led to the introduction of novel agents against specific patients with programmed death-ligand 1 (PD-L1)-positive TNBC who harbor germline BRCA mutations. However, some patients who respond to PD-L1 or poly (ADP-ribose) polymerase PARP inhibitors often develop resistance. Additionally, treatment strategies are more complicated for patients with PD-L1-positive TNBC and germline BRCA mutations. Here, we report a patient with metastatic PD-L1-positive TNBC who harbored a germline BRCA1 mutation. The patient sequentially received combination treatment regimens, including PD-L1 inhibitors with chemotherapy and the PARP inhibitor olaparib, acquiring resistance to the treatments in a couple of months. Further investigations are warranted to elucidate the mechanisms underlying resistance to PD-L1 antibodies and PARP inhibitors to improve treatment outcomes while preventing emergence of treatment resistance in patients with TNBC.

Enrichment of Immune-Related Genes in Aggressive Primary Breast Angiosarcoma: A Case Report.

Primary breast angiosarcoma is an extremely rare disease with a poor prognosis. Primary angiosarcoma is distinct from secondary angiosarcoma, which usually occurs in patients who have been previously treated for breast cancer. The low incidence of primary breast angiosarcoma has hindered the elucidation of its etiology and potential therapies. Here, we report a case of a patient with primary breast angiosarcoma who experienced recurrence after surgery. The tumor was refractory to systemic treatments, and the patient died 18 months after the surgery. We used RNA sequencing for gene expression profiling of the tumor. A high tumor inflammation signature score indicated enrichment in immune-related signaling. CIBERSORTx, a tool used to characterize the cellular composition of complex tissues based on gene expression, indicated that the immune cells in the tumor were predominantly macrophages, and this was confirmed using immunohistochemical analysis. These findings indicate the possible use of checkpoint immunotherapy for the treatment of primary breast angiosarcoma.

Long-term response to olaparib in a patient with metastatic pancreatic cancer associated with hereditary breast and ovarian cancer syndrome.

BRCA mutations are associated with an increased risk of pancreatic cancer (PC). Olaparib, an oral poly (adenosine diphosphate-ribose) polymerase (PARP) inhibitor, has been approved for the treatment of metastatic PC with a germline BRCA mutation. In this report, we present the case of a metastatic PC harboring a germline BRCA2 mutation, and the daughter of the patient, who had bilateral breast cancers harboring the same germline mutation, suggesting that the PC was associated with hereditary breast and ovarian cancer syndrome. Although PC is an aggressive disease and has poor prognosis, olaparib was administered as maintenance therapy following modified FOLFIRINOX, providing clinical benefits for >12 months.

Comparison of the Modified Immunohistochemical Marker Score and 21-Gene Recurrence Score Assay in Patients with Estrogen Receptor-Positive Breast Cancer.

INTRODUCTION: Not only the 21-gene recurrence score (RS) assay but also online prognostic tools and immunohistochemical prognostic models predict chemotherapy benefits for women with early breast cancer (BC). Multigene assays, including Oncotype DX, are expensive and not covered by insurance in some countries Methods: In this study, we retrospectively analyzed a series of 155 patients with estrogen receptor-positive primary BC for whom an Oncotype DX assay was performed between January 2016 and August 2021. The patients' modified immunohistochemical marker (mIHC4) scores were calculated on the basis of their pathological reports. The correlations of the RS with the online tool PREDICT and mIHC4 scores were evaluated. RESULTS: Of the patients, 43.9% were premenopausal, 147 (94.8%) had T1 or T2 tumor, and 55.5% had no positive lymph nodes. Low (0-10), intermediate (11-25), and high RSs (26-100) were obtained in 16.1%, 61.9%, and 21.9% of the patients, respectively. The RS showed no correlation with the PREDICT score (r = 0.2720) but correlated with the mIHC4 score (r = 0.6356). In addition, a stronger correlation was observed in the patients with no node involvement and in the postmenopausal patients (r = 0.6609 and r = 0.7277, respectively). CONCLUSIONS: A relatively strong correlation was observed between the RS and the mIHC4 score. The mIHC4 score is a potentially easy and useful tool to guide adjuvant chemotherapy decision making, especially for postmenopausal patients with no node involvement if a genomic test could not be performed for some reason.

Pathological Complete Response to Neoadjuvant Chemotherapy in a Patient with HER2-Positive Squamous Cell Carcinoma of the Breast.

Squamous cell carcinoma (SCC) of the breast is a rare malignancy that usually has a triple-negative phenotype and poor clinical outcomes. Because HER2-positive SCC of the breast is extremely rare, its clinicopathologic features are understudied, and the effects of neoadjuvant chemotherapy including anti-HER2-targeted therapy on the tumor are unclear, although treatment resistance was described in some reports. In this study, we reported a case of HER2-positive SCC of the breast in which a pathological complete response to neoadjuvant chemotherapy was observed.

Large Breast Tumor Ulceration and Quality of Life in an 80-Year-Old Woman.

Advanced breast cancer with skin ulceration, bleeding, and odor is associated with impaired quality of life (QoL). In patients with metastatic breast cancer, treatment aims to relieve symptoms, improve QoL, and slow the progression of cancer. Occasionally, it is extremely difficult to alleviate symptoms and improve QoL in patients with breast cancer and skin ulceration, especially elderly patients. Since patient age, patient preferences, and the expected survival benefit from treatment are factors that influence the selection of therapy, physicians should provide an optimal treatment for patients with metastatic disease depending on the situation. In this study, we report the case of an elderly patient with metastatic breast cancer who had substantial skin ulceration. In this patient, multidisciplinary treatment including chemotherapy, radiotherapy, and surgery resulted in significantly improved QoL.

Pneumocystis Pneumonia and Acute Kidney Injury Induced by Everolimus Treatment in a Patient with Metastatic Breast Cancer.

Everolimus, an inhibitor of the rapamycin pathway, is administered with the combination of an aromatase inhibitor for the treatment of metastatic estrogen receptor (ER)-positive and human epidermal growth factor receptor 2 (HER2)-negative breast cancers. Interstitial lung disease is a well-known major adverse event associated with everolimus treatment, but it is often difficult to distinguish between interstitial lung disease and Pneumocystis pneumonia, a lung infection. Acute kidney injury is another adverse event that is associated with everolimus use. In this article, we report a case of Pneumocystis pneumonia without respiratory symptoms and acute kidney injury induced by everolimus treatment in a patient with ER-positive and HER2-negative metastatic breast cancer.

Concurrent Bowen's Disease of the Nipple and Breast Cancer.

Bowen's disease is a squamous cell carcinoma in situ that commonly develops on the trunk, arms, or legs and has not spread beyond the top layer of skin. It seldom develops on the nipple. We report a patient who presented with Bowen's disease of the nipple and had a concurrent breast cancer identified in the ipsilateral breast after careful examination. Histopathological examination of the surgical specimen after mastectomy confirmed the diagnoses.

Fertility preservation before neoadjuvant chemotherapy in a premenopausal breast cancer patient: a case report.

Neoadjuvant chemotherapy is now a widely accepted treatment modality for operable breast cancer and therefore fertility preservation is an important component of care for young patients with breast cancer. It is critical that oocyte retrieval is completed without delays in the initiation of neoadjuvant chemotherapy. Here we report the case of a 34-year-old woman who was diagnosed with Stage IIA triple-negative breast cancer and underwent ovarian stimulation for fertility preservation prior to the initiation of neoadjuvant chemotherapy. Oocytes were retrieved and in vitro fertilization was conducted before neoadjuvant chemotherapy was started. Upon completion of neoadjuvant chemotherapy, the patient underwent breast surgery. Subsequently, a pathological complete response was achieved. She received a frozen embryo transfer 10 months after breast surgery. The patient became pregnant and delivered a healthy baby.

Response of Estrogen-Receptor-Positive Metastatic Breast Cancer to Olaparib in Late-Line Therapy.

Monotherapy with olaparib provides significant benefits over standard therapy in patients with a germline BRCA mutation and human epidermal growth factor receptor 2 (HER2) negative metastatic breast cancer, who had two or fewer previous chemotherapeutic regimens for metastatic disease. Olaparib was approved on July 2, 2018, in Japan for the treatment of patients with metastatic breast cancer with a BRCA mutation and HER2-negative status. Thus, the current experience with this drug is relatively limited. In this article, we report a case of luminal-type metastatic breast cancer harboring a BRCA1 mutation detected through BRACAnalysis (Myriad Genetics). Despite the late-line treatment, in this patient, olaparib was effective against metastatic breast cancer.

Feasibility Study of Weekly Nanoparticle Albumin-Bound Paclitaxel (150 mg/m2) Followed by Fluorouracil, Epirubicin, and Cyclophosphamide Therapy as Neoadjuvant Chemotherapy for HER2-Negative Breast Cancer.

BACKGROUND: Although several studies have shown efficacy of nanoparticle albumin-bound (nab) paclitaxel use as a neoadjuvant treatment in breast cancer, dosage and schedules were varied or used in combination and the data are still limited for weekly regimens. We evaluated the feasibility of weekly nab-paclitaxel followed by FEC (5-FU [fluorouracil], epirubicin, and cyclophosphamide) treatment feasibility as neoadjuvant chemotherapy for breast cancer. PATIENTS AND METHODS: Thirty-three patients with no previous chemotherapy were enrolled to receive nab-paclitaxel 150 mg/m2 the first 3 of 4 weeks (3q4w) followed by FEC as neoadjuvant treatment. The trial was powered for analyses of feasibility. RESULTS: Twenty-five patients completed the treatment as per protocol, and the completion rate was 75.8% (95% confidence interval, 59.0-87.2; P = .44). The regimen completion group was younger than those with regimen incompletion (average 45.1 vs. 56.6 years). The pathological complete response (ypT0-is/N0) rate was 30.3% in 33 patients, which was higher in triple-negative patients (58.3%). Grade 3/4 neutropenia was seen in 48.5%, although there was no febrile neutropenia. Grade 3 peripheral neuropathy was seen in 33.3%. CONCLUSION: Our study showed that weekly nab-paclitaxel 150 mg/m2 3q4w followed by FEC as neoadjuvant regimen might be sufficient in efficacy, although with a relatively high severe adverse event occurrence rate.

Oncologic outcomes and technical considerations of nipple-sparing mastectomies in breast cancer: experience of 425 cases from a single institution.

BACKGROUND: Nipple-sparing mastectomy (NSM) is an advantageous treatment option, providing a complete cure and good cosmetic results. We tested whether NSM is a surgically and oncologically safe technique. METHODS: We evaluated the oncological outcome of 425 breasts in 413 patients who underwent NSM between January 2000 and March 2013. We retrospectively reviewed patient data and analyzed all patient characteristics as potential risk factors of recurrence at the nipple-areola complex (NAC). To confirm the oncological safety of NSM, we compared outcomes of NSM and conventional total mastectomy. RESULTS: The median follow-up time after surgery was 46.8 months (range 6-158 months). Nipple necrosis was observed in 6 cases (1.4 %). The cumulative local recurrence rate after NSM was 5.8 % (25/425 cases), similar to that of conventional total mastectomy in the same period (5.6 %, 49/878 cases). Furthermore, the cumulative local recurrence rate at the NAC was 2.3 % (10 cases). HER2-enriched tumors and young age (<40 years) were significant risk factors for recurrence at the NAC. In patients with recurrence, the site of recurrence was easily excised, and good cosmetic results were achieved in breast reconstruction cases. CONCLUSION: NSM is safe with a low complication rate. No significant difference was observed in cumulative local recurrence rate, cumulative distant disease recurrence rate, and overall survival between patients who underwent NSM or conventional total mastectomy, confirming that NSM was surgically and oncologically safe.

[Thrombophlebitis in an Elderly Japanese Woman Treated with Tamoxifen for Breast Cancer].

In this study, we report the rare case of an elderly woman who developed thrombophlebitis after being treated with tamoxifen for breast cancer. She visited our department with a lump in her left breast. She underwent core needle biopsy, and she was diagnosed with breast cancer (invasive ductal carcinoma, ER- and PgR-positive, HER2-negative). We chose hormonal therapy because surgical treatment was deemed too invasive considering her general status. She was administered tamoxifen (20 mg/day) instead of an aromatase inhibitor in consideration of her osteoporosis. Six months after initiating tamoxifen therapy, she exhibited swelling in her left leg. Computed tomography and ultrasound revealed thrombophlebitis in her left femoral vein. She stopped taking tamoxifen and started warfarin potassium as thrombolytic therapy, after which thrombophlebitis was relieved. Advanced age may be a risk factor for thrombophlebitis associated with tamoxifen treatment; therefore, precautions should be taken accordingly.

Class I histone deacetylase inhibitors inhibit the retention of BRCA1 and 53BP1 at the site of DNA damage.

BRCA1 and 53BP1 antagonistically regulate homology-directed repair (HDR) and non-homologous end-joining (NHEJ) of DNA double-strand breaks (DSB). The histone deacetylase (HDAC) inhibitor trichostatin A directly inhibits the retention of 53BP1 at DSB sites by acetylating histone H4 (H4ac), which interferes with 53BP1 binding to dimethylated histone H4 Lys20 (H4K20me2). Conversely, we recently found that the retention of the BRCA1/BARD1 complex is also affected by another methylated histone residue, H3K9me2, which can be suppressed by the histone lysine methyltransferase (HKMT) inhibitor UNC0638. Here, we investigate the effects of the class I HDAC inhibitors MS-275 and FK228 compared to UNC0638 on histone modifications and the DNA damage response. In addition to H4ac, the HDAC inhibitors induce H3K9ac and inhibit H3K9me2 at doses that do not affect the expression levels of DNA repair genes. By contrast, UNC0638 selectively inhibits H3K9me2 without affecting the levels of H3K9ac, H3K56ac or H4ac. Reflecting their effects on histone modifications, the HDAC inhibitors inhibit ionizing radiation-induced foci (IRIF) formation of BRCA1 and BARD1 as well as 53BP1 and RIF1, whereas UNC0638 suppresses IRIF formation of BRCA1 and BARD1 but not 53BP1 and RIF1. Although HDAC inhibitors suppressed HDR, they did not cooperate with the poly(ADP-ribose) polymerase inhibitor olaparib to block cancer cell growth, possibly due to simultaneous suppression of NHEJ pathway components. Collectively, these results suggest the mechanism by that HDAC inhibitors inhibit both the HDR and NHEJ pathways, whereas HKMT inhibitor inhibits only the HDR pathway; this finding may affect the chemosensitizing effects of the inhibitors.

MED12 exon 2 mutations in phyllodes tumors of the breast.

Exon 2 of MED12, a subunit of the transcriptional mediator complex, has been frequently mutated in uterine leiomyomas and breast fibroadenomas; however, it has been rarely mutated in other tumors. Although the mutations were also found in uterine leiomyosarcomas, the frequency was significantly lower than in uterine leiomyomas. Here, we examined the MED12 mutation in phyllodes tumors, another biphasic tumor with epithelial and stromal components related to breast fibroadenomas. Mutations in MED12 exon 2 were analyzed in nine fibroadenomas and eleven phyllodes tumors via Sanger sequencing. A panel of cancer- and sarcoma-related genes was also analyzed using Ion Torrent next-generation sequencing. Six mutations in fibroadenomas, including those previously reported (6/9, 67%), and five mutations in phyllodes tumors (5/11, 45%) were observed. Three mutations in the phyllodes tumors were missense mutations at Gly44, which is common in uterine leiomyomas and breast fibroadenomas. In addition, two deletion mutations (in-frame c.133_144del12 and loss of splice acceptor c.100-68_137del106) were observed in the phyllodes tumors. No other recurrent mutation was observed with next-generation sequencing. Frequent mutations in MED12 exon 2 in the phyllodes tumors suggest that it may share genetic etiology with uterine leiomyoma, a subgroup of uterine leiomyosarcomas and breast fibroadenoma.

BRCA1 ubiquitinates RPB8 in response to DNA damage.

The breast and ovarian tumor suppressor BRCA1 catalyzes untraditional polyubiquitin chains that could be a signal for processes other than proteolysis. However, despite intense investigations, the mechanisms regulated by the enzyme activity remain only partially understood. Here, we report that BRCA1-BARD1 mediates polyubiquitination of RPB8, a common subunit of RNA polymerases, in response to DNA damage. A proteomics screen identified RPB8 as a protein modified after epirubicin treatment in BRCA1-dependent manner. RPB8 interacted with BRCA1-BARD1 and was polyubiquitinated by BRCA1-BARD1 in vivo and in vitro. BRCA1-BARD1 did not destabilize RPB8 in vivo but rather caused an increase in the amount of soluble RPB8. Importantly, RPB8 was polyubiquitinated immediately after UV irradiation in a manner sensitive to BRCA1 knockdown by RNA interference. Substitution of five lysine residues of RPB8 with arginine residues abolished its ability to be ubiquitinated while preserving its polymerase activity. HeLa cell lines stably expressing this ubiquitin-resistant form of RPB8 exhibited UV hypersensitivity accompanied by up-regulated caspase activity. Our findings suggest that ubiquitination of a common subunit of RNA polymerases is a mechanism underlying BRCA1-dependent cell survival after DNA damage.

A truncated splice variant of human BARD1 that lacks the RING finger and ankyrin repeats.

BARD1 is a crucial partner of the breast and ovarian tumor suppressor BRCA1 required for ubiquitin ligase activity and for reciprocal stabilization in cells. We report here an alternatively spliced human BARD1 mRNA variant (BARD1DeltaRIN) isolated from a HeLa cell cDNA library. It is characterized by deletion of exons 2-6 that encode most of the RING finger domain and the entire span of ankyrin repeats. DeltaRIN transcript was detected in all breast cancer-cell lines studied although its protein expression level was low. DeltaRIN does not interact with BRCA1, whereas it interacts with and colocalizes with CstF-50 to cytoplasmic dots. Hence, a deletion variant of BARD1 occurs in cells and may play a distinct role with CstF-50.

Down-regulation of BRCA1-BARD1 ubiquitin ligase by CDK2.

BRCA1, a breast and ovarian tumor suppressor, is a phosphoprotein whose cellular expression level is regulated in a cell cycle-dependent manner. BRCA1 interacts with BARD1 to generate significant ubiquitin ligase activity which catalyzes nontraditional Lys-6-linked polyubiquitin chains. However, it is not clear how the activity is regulated and how this affects BRCA1's multiple cellular functions. Here we show that the ubiquitin ligase activity of BRCA1-BARD1 is down-regulated by CDK2. During the cell cycle, BARD1 expression can largely be categorized into three patterns: moderately expressed in a predominantly unphosphorylated form in early G(1) phase, expressed at low levels in both phosphorylated and unphosphorylated forms during late G(1) and S phases, and highly expressed in its phosphorylated form during mitosis coinciding with BRCA1 expression. CDK2-cyclin A1/E1 and CDK1-cyclin B1 phosphorylate BARD1 on its NH(2) terminus in vivo and in vitro. Intriguingly, the BRCA1-BARD1-mediated in vivo ubiquitination of nucleophosmin/B23 (NPM) and autoubiquitination of BRCA1 are dramatically disrupted by coexpression of CDK2-cyclin A1/E1, but not by CDK1-cyclin B1. The inhibition of ubiquitin ligase activity is not due to the direct effect of the kinases on BARD1 because an unphosphorylatable mutant of BARD1, S148A/S251A/S288A/T299A, is still inhibited by CDK2-cyclin E1. Alternatively, BRCA1 and BARD1 are likely exported to the cytoplasm and their expressions are remarkably reduced by CDK2-cyclin E1 coexpression. Recognizing the importance of cyclin E1 overexpression in breast cancer development, these results suggest a CDK2-BRCA1-NPM pathway that coordinately functions in cell growth and tumor progression pathways.

Nucleophosmin/B23 is a candidate substrate for the BRCA1-BARD1 ubiquitin ligase.

The breast and ovarian tumor suppressor BRCA1 forms a heterodimeric RING-type ubiquitin ligase with BARD1 to catalyze untraditional Lys-6-linked polyubiquitin chains. It is not clear how the BRCA1-BARD1 ligase regulates various cellular processes such as DNA repair, cell-cycle progression, transcriptional regulation, and centrosome duplication. Here we report that BRCA1-BARD1 catalyzes the polyubiquitination of nucleolar phosphoprotein nucleophosmin/B23 (NPM). Two different mass spectrometry screens for protein ubiquitinated by BRCA1-BARD1 both identified NPM. NPM interacts with N-terminal fragments of BRCA1 and BARD1 in a manner dependent upon BRCA1-BARD1 heterodimer formation. NPM colocalizes with BRCA1 and BARD1 in mitotic cells suggesting the possibility of NPM regulation by BRCA1-BARD1 during mitosis. BRCA1-BARD1 catalyzes the ubiquitination of NPM in vitro and in vivo, and BRCA1-BARD1 co-expression in cells causes NPM stabilization rather than degradation. This is consistent with the notion that this ligase catalyzes untraditional polyubiquitin chains. Given the many overlapped functions between NPM and BRCA1, we propose that NPM is a strong candidate as a substrate of the BRCA1-BARD1 ubiquitin ligase.