Photodynamic therapy with paclitaxel-encapsulated indocyanine green-modified liposomes for breast cancer.

Background: Photodynamic therapy (PDT) involves the administration of a photosensitizing agent and irradiation of light at an excitation wavelength that damages tumor cells without causing significant damage to normal tissue. We developed indocyanine green (ICG)-modified liposomes in which paclitaxel (PTX) was encapsulated (ICG-Lipo-PTX). ICG-Lipo-PTX accumulates specifically in tumors due to the characteristics of the liposomes. The thermal and photodynamic effects of ICG and the local release of PTX by irradiation are expected to induce not only antitumor effects but also cancer immunity. In this study, we investigated the antitumor effects of ICG-Lipo-PTX in breast cancer. Methods: The antitumor effects of ICG-Lipo-PTX were examined in xenograft model mice subcutaneously implanted with KPL-1 human breast cancer cells. ICG-Lipo-PTX, ICG-Lipo, or saline was administered intraperitoneally, and the fluorescence intensity was measured with a fluorescence imaging system (IVIS). Intratumor temperature, tumor volume, and necrotic area of tumor tissue were also compared. Next, we investigated the induction of cancer immunity in an allogeneic transplantation model in which BALB-MC mouse breast cancer cells were transplanted subcutaneously in the bilateral inguinal region. ICG-Lipo-PTX was administered intraperitoneally, and PDT was performed on only one side. The fluorescence intensity measured by IVIS and the bilateral tumor volumes were compared. Cytokine secretory capacity was also evaluated by ELISPOT assay using splenocytes. Results: In the xenograft model, the fluorescence intensity and temperature during PDT were significantly higher with ICG-Lipo-PTX and ICG-Lipo in tumor areas than in nontumor areas. The fluorescence intensity in the tumor area was reduced to the same level as that in the nonirradiated area after two times of irradiation. Tumor growth was significantly reduced and the percentage of necrotic area in the tumor was higher after PDT in the ICG-Lipo-PTX group than in the other groups. In the allograft model, tumor growth on day 14 in the ICG-Lipo-PTX group was significantly suppressed not only on the PDT side but also on the non-PDT side. In addition, the secretion of interferon-γ and interleukin-2 was enhanced, whereas that of interleukin-10 was suppressed, in the ICG-Lipo-PTX group. Conclusion: The PDT therapy with ICG-Lipo-PTX may be an effective treatment for breast cancer.

A risk-based subgroup analysis of the effect of adjuvant S-1 in estrogen receptor-positive, HER2-negative early breast cancer.

PURPOSE: The Phase III POTENT trial demonstrated the efficacy of adding S-1 to adjuvant endocrine therapy for estrogen receptor-positive, HER2-negative early breast cancer. We investigated the efficacy of S-1 across different recurrence risk subgroups. METHODS: This was a post-hoc exploratory analysis of the POTENT trial. Patients in the endocrine-therapy-only arm were divided into three groups based on composite risk values calculated from multiple prognostic factors. The effects of S-1 were estimated using the Cox model in each risk group. The treatment effects of S-1 in patients meeting the eligibility criteria of the monarchE trial were also estimated. RESULTS: A total of 1,897 patients were divided into three groups: group 1 (≤ lower quartile of the composite values) (N = 677), group 2 (interquartile range) (N = 767), and group 3 (> upper quartile) (N = 453). The addition of S-1 to endocrine therapy resulted in 49% (HR: 0.51, 95% CI: 0.33-0.78) and 29% (HR: 0.71, 95% CI 0.49-1.02) reductions in invasive disease-free survival (iDFS) events in groups 2 and 3, respectively. We could not identify any benefit from the addition of S-1 in group 1. The addition of S-1 showed an improvement in iDFS in patients with one to three positive nodes meeting the monarchE cohort 1 criteria (N = 290) (HR: 0.47, 95% CI: 0.29-0.74). CONCLUSIONS: The benefit of adding adjuvant S-1 was particularly marked in group 2. Further investigations are warranted to explore the optimal usage of adjuvant S-1.

De-differentiation in cultures of organoids from luminal-type breast cancer is restored by inhibition of NOTCH signaling.

Estrogen receptor (ER) expression in breast cancer can change during progression and the treatment, but the mechanism has not been well studied. In this study, we successfully prepared organoids from samples obtained from 33 luminal-type breast cancer patients and studied their ER expression. The expression status was well maintained in primary organoids, whereas it decreased after passaging in most of the cases. In fact, the studied organoid lines were classified into those that retained a high level of ER expression (9%), those that completely lost it (9%), and those that repressed it to varying degrees (82%). In some cases, the ER expression was suddenly and drastically decreased after passaging. Marker protein immunohistochemistry revealed that after passaging, the differentiation status shifted from a luminal- to a basal-like status. Differentially expressed genes suggested the activation of NOTCH signaling in the passaged organoids, wherein a NOTCH inhibitor was able to substantially rescue the decreased ER expression and alter the differentiation status. Our findings suggest that the differentiation status of luminal-type cancer cells is quite flexible, and that by inhibiting the NOTCH signaling we can preserve the differentiation status of luminal-type breast cancer organoids.

Dramatic Recovery of Vision after Trastuzumab Deruxtecan Treatment of HER2-Positive Breast Cancer with Pituitary Metastasis.

In recent years, both the number of patients with breast cancer and those with associated brain metastases (BMs) have increased. Human epidermal growth factor receptor 2 (HER2)-positive breast cancer has a high BM frequency. The prognosis of BM from breast cancer is poor, and establishing effective treatment for this disease is essential. We report a HER2-positive patient with multiple BM and right-eye blindness due to pituitary metastasis. She responded promptly to trastuzumab deruxtecan (T-DXd) in the 5th line of treatment, which shrunk the tumors and restored vision. Although the Graded Prognostic Assessment (GPA) predicted survival of 13 months, the patient recovered well after treatment and continued T-DXd use with no progression, including vision loss at 22 months after treatment initiation. This case demonstrates the successful action of T-DXd in the face of multiple BM and poorly predicted outcomes.

Reproducibility assessment of uptake on dedicated breast PET for noise discrimination.

OBJECTIVES: Dedicated breast PET (dbPET) systems have improved the detection of small breast cancers but have increased false-positive diagnoses due to an increased chance of noise detection. This study examined whether reproducibility assessment using paired images helped to improve noise discrimination and diagnostic performance in dbPET. METHODS: This study included 21 patients with newly diagnosed breast cancer who underwent [18F]FDG-dbPET and contrast-enhanced breast MRI. A 10-min dbPET data scan was acquired per breast, and two sets of reconstructed images were generated (named dbPET-1 and dbPET-2, respectively), each of which consisted of randomly allocated 5-min data from the 10-min data. Uptake spots higher than the background were indexed for the study with visual assessment. All indexed uptakes on dbPET-1 were evaluated using dbPET-2 for reproducibility. MRI findings based on the Breast Imaging-Reporting and Data System (BI-RADS) 2013 were used as the gold standard. Uptake spots that corresponded to BI-RADS 1 on MRI were considered noise, while those with BI-RADS 4b-6 were considered malignancies. The diagnostic performance of dbPET for malignancy was evaluated using four different criteria: any uptake on dbPET-1 regarded as positive (criterion A), a subjective visual assessment of dbPET-1 (criterion B), reproducibility assessment between dbPET-1 and dbPET-2 (criterion C), and a combination of B and C (criterion D). RESULTS: A total of 213 indexed uptake spots were identified on dbPET-1, including 152, 15, 6, 6, and 34 lesions classified as BI-RADS MRI categories 1, 2, 4b, 4c, and 5, respectively. Overall, 31.9% of the index uptake values were reproducible. All malignant lesions were reproducible, whereas 93.4% of noise was not reproducible. The sensitivities for malignancy for criteria A, B, C, and D were 100%, 91.3%, 100%, and 91.3%, respectively, with positive predictive values (PPVs) of 21.4%, 68.9%, 67.6%, and 82.4%, respectively. CONCLUSIONS: Our results demonstrated that reproducibility assessment helped reduce false-positive findings caused by noise on dbPET without lowering the sensitivity for malignancy. While subjective visual assessment was also efficient in increasing PPV, it occasionally missed malignant uptake.

Systematically higher Ki67 scores on core biopsy samples compared to corresponding resection specimen in breast cancer: a multi-operator and multi-institutional study.

Ki67 has potential clinical importance in breast cancer but has yet to see broad acceptance due to inter-laboratory variability. Here we tested an open source and calibrated automated digital image analysis (DIA) platform to: (i) investigate the comparability of Ki67 measurement across corresponding core biopsy and resection specimen cases, and (ii) assess section to section differences in Ki67 scoring. Two sets of 60 previously stained slides containing 30 core-cut biopsy and 30 corresponding resection specimens from 30 estrogen receptor-positive breast cancer patients were sent to 17 participating labs for automated assessment of average Ki67 expression. The blocks were centrally cut and immunohistochemically (IHC) stained for Ki67 (MIB-1 antibody). The QuPath platform was used to evaluate tumoral Ki67 expression. Calibration of the DIA method was performed as in published studies. A guideline for building an automated Ki67 scoring algorithm was sent to participating labs. Very high correlation and no systematic error (p = 0.08) was found between consecutive Ki67 IHC sections. Ki67 scores were higher for core biopsy slides compared to paired whole sections from resections (p ≤ 0.001; median difference: 5.31%). The systematic discrepancy between core biopsy and corresponding whole sections was likely due to pre-analytical factors (tissue handling, fixation). Therefore, Ki67 IHC should be tested on core biopsy samples to best reflect the biological status of the tumor.

Prognostic significance of the expression levels of T-cell immunoglobulin mucin-3 and its ligand galectin-9 for relapse-free survival in triple-negative breast cancer.

T-cell immunoglobulin mucin-3 (TIM-3) expressed at the T-cell surface acts as an immune checkpoint when bound by its ligand galectin-9. Blockade of immunosuppression by the TIM3/galectin-9 signalling pathway may offer novel therapeutic approaches for cancer immunotherapy. Consistent with this, TIM-3 expression is associated with poorer prognosis in several different types of cancer, possibly as a result of suppression of anticancer immunosurveillance. A number of studies have now documented some effectiveness of immune checkpoint blockade even in triple-negative breast cancer (TNBC), which is highly aggressive. However, clinical responses are relatively weak, suggesting that several different pathways may be involved. In this context, the role of the TIM-3/galectin-9 checkpoint in TNBC is not clear. The present study aimed to determine the clinicopathological significance of TIM-3 and galectin-9 expression in this cancer. To this end, 62 patients with TNBC undergoing surgery at Kansai Medical University Hospital (Hirakata, Japan), but not given neoadjuvant chemotherapy, were examined. Tissue microarrays were employed for immunohistochemistry to analyse associations of TIM-3 and galectin-9 expression and their impact on relapse-free survival relative to other poor prognostic risk factors. Galectin-9 expression was detected in 49 of 62 patient samples (79%), and TIM-3 in 30 of them (48.4%). Tumour cell galectin-9 expression was associated with a more favourable prognosis (P=0.027) as was TIM-3 expression on tumour-infiltrating lymphocytes (P=0.007). Multivariate analysis indicated that galectin-9- and TIM-3-double-positivity was significantly associated with a more favourable prognosis compared with galectin-9 and/or TIM-3 negativity (P=0.044). Thus, the TIM-3/galectin-9 signalling pathway may impact anticancer immune reactions in the tumour microenvironment of patients with TNBC. Further investigation will be necessary to determine the molecular mechanisms underlying these relationships.

Effectiveness of eribulin as first-line or second-line chemotherapy for HER2-negative hormone-resistant advanced or metastatic breast cancer: findings from the multi-institutional, prospective, observational KBCRN A001: E-SPEC study.

BACKGROUND: The optimal positioning of eribulin treatment remains unclear. This study aimed to investigate the effectiveness of eribulin administration as first- and second-line chemotherapy in patients with endocrine-resistant advanced or metastatic breast cancer (AMBC) in the real-world clinical setting. METHODS: This multi-institutional prospective cohort study enrolled patients with triple-negative AMBC or estrogen receptor-positive AMBC refractory to at least one previous endocrine therapy. The overall survival (OS) from the start of first-line (OS1) and second-line chemotherapy (OS2) was assessed. Data analysis included real-world chemotherapy sequences of first- to third-line chemotherapy regimens. The adjusted hazard ratio (HR) with 95% confidence interval (CI) for treatment regimen comparison was calculated using a stratified proportional hazards model. RESULTS: Among 201 patients enrolled, 180 were included in the final analysis. Eribulin was administered as first- and second-line chemotherapy to 46 (26.6%) and 70 (47.9%) patients, respectively. Median OS1 and OS2 were 2.25 (95% CI 1.07-2.68) and 1.75 (95% CI, 1.28-2.45) years for first- and second-line eribulin, respectively. Oral 5-FU followed by eribulin had a numerically longer OS1 (2.84 years) than the other sequences. Among patients who proceeded to second-line or later chemotherapy, the median OS1 for those treated with anthracycline or taxane as first- or second-line (n = 98) was 2.56 years (95% CI 2.27-2.74), while it was 2.87 years (95% CI 2.20-4.32) for those who avoided anthracycline and taxane as first- and second-line (n = 48) (adjusted HR, 1.20; 95% CI 0.70-2.06). In the exploratory analysis, OS1 was 2.55 (95% CI 2.14-2.75) and 2.91 years (95% CI 2.61-4.32) for those aged < 65 and ≥ 65 years, respectively (adjusted HR of ≥ 65, 0.91; 95% CI 0.56-1.46). CONCLUSIONS: Eribulin or oral 5-FU administration in first- and second-line chemotherapy without anthracycline/taxane was acceptable in the real-world setting. TRIAL REGISTRATION: This study is registered with Clinical Trials.gov (NCT 02,551,263).

Immunohistochemical analyses of the expression profiles of INSM1, ATRX, DAXX and DLL3 in solid papillary carcinomas of the breast.

Solid papillary carcinoma (SPC) is a rare but distinct clinicopathological feature of breast cancer characterised by frequent neuroendocrine differentiation. Insulinoma-associated protein 1 (INSM1) is a useful neuroendocrine marker for various neuroendocrine tumours. α-thalassemia/mental retardation syndrome X-linked protein (ATRX) and death domain-associated protein (DAXX) are useful prognostic markers for patients with pancreatic neuroendocrine tumours. However, to the best of our knowledge, few studies have addressed INSM1 expression in SPCs. Although ATRX, DAXX and δ-like canonical notch ligand 3 (DLL3) are frequently expressed in neuroendocrine lung carcinomas, there are no reports on their expression in SPCs. Therefore, the present study aimed to analyse the expression profiles of INSM1, ATRX, DAXX and DLL3 in the largest series of patients with SPC that has been, to the best of our knowledge, studied until now. Immunohistochemical analyses were performed to determine chromogranin A, synaptophysin, INSM1, ATRX, DAXX and DLL3 expression in 39 specimens surgically resected from patients with SPC (18 SPC in situ and 21 SPC invasive). The associations between the expression of these markers and the clinicopathological factors were investigated. Chromogranin A, synaptophysin and INSM1 were expressed in 64.1, 100 and 92.3% of the patients, respectively. Both ATRX and DAXX expression was observed in 28.2% of the patients. No patient expressed DLL3. Lack of INSM1 or chromogranin A expression was significantly associated with advanced pathological stages in patients with SPC (P=0.033) and in patients with invasive SPC (P=0.012), showing a tendency for a high Ki-67 labelling index (LI) and advanced histological grade in patients with invasive SPC. Loss of ATRX or DAXX expression was significantly associated with lymphatic invasion, but not with histological grade, Ki-67 LI or presence of invasive tumours. Thus, INSM1 was demonstrated to be a useful diagnostic marker for SPCs. Overall, detecting the lack of INSM1 or chromogranin A expression may be useful for analysing the characteristics of tumour cells in SPCs.

Prognostic significance of adipophilin expression in biopsy specimens of patients with triple-negative breast cancer.

Triple-negative breast cancer (TNBC) is the most aggressive type of breast cancer. The present authors recently demonstrated that expression of the lipid-related protein adipophilin (ADP) in operative specimens is a significant poor prognostic factor in patients with TNBC. Using biopsy specimens is important in making clinical decisions for patients with breast cancer; however, the prognostic significance of ADP expression in biopsy specimens from TNBC patients remains unclear. The present study determined the prognostic significance of ADP expression in biopsy specimens from TNBC patients and compared ADP-expression status between biopsy and operative specimens. The present study analyzed ADP-expression profiles in biopsy specimens from 102 patients with TNBC using immunohistochemical staining and determined relapse-free survival and risk factors associated with ADP expression in these specimens, as well as the concordance of ADP expression between biopsy and operative specimens. The results identified ADP expression in 35.3% of biopsy specimens from TNBC patients. The Ki-67 labelling index was significantly higher in ADP-positive patients (P<0.001). Univariate analysis revealed that ADP expression in biopsy specimens was significantly associated with poor relapse-free survival in patients not administered neoadjuvant chemotherapy or adjuvant chemotherapy (P=0.026). Furthermore, the concordance rate of ADP expression between biopsy and operative specimens was 73.1%, with a Cohen's kappa coefficient of 0.385 (P=0.003). These findings suggested that ADP expression in biopsy specimens might be a useful prognostic marker for patients with TNBC and could potentially provide important information regarding treatment strategies for these patients.

Association between fatty acid synthase and adipophilin expression in triple-negative breast cancer.

It is well known that cancer cells produce energy via anaerobic glycolysis. Lipid metabolism is often upregulated in numerous types of cancer. Our previous study demonstrated that adipophilin (ADP), a lipid-associated protein, was a poor prognostic indicator in patients with triple-negative breast cancer (TNBC). However, the mechanism of ADP expression in TNBC remains unclear. Fatty acid synthase (FASN) is a crucial enzyme in de novo fatty acid synthesis, and its upregulation has been reported in several types of carcinomas; however, to the best of our knowledge, the association of FASN and ADP in TNBC remains unclear. The present study analysed the association between FASN and ADP expression and the prognostic significance of FASN in TNBC. Using immunohistochemical methods and tissue microarrays, the present study examined FASN expression in 61 patients with TNBC. Overall and relapse-free survival and their risk factors were analysed for FASN expression and compared with ADP expression. A total of 40 (65.6%) patients were classified as FASN-high (score ≥120), and this was significantly associated with a lower Ki-67 labelling index (P=0.011). FASN expression was not associated with relapse-free survival and overall survival. FASN-high was negatively associated with ADP expression (P=0.041). The results of the present study revealed that FASN-high was associated with a lack of ADP expression and a lower Ki-67 labelling index. These results indicated that de novo fatty acid synthesis by FASN is not the main pathway of lipogenesis and the source of energy in cancer cells of ADP-positive highly proliferative TNBC.

Case-based survey: The impact of breast-cancer treatment on fertility in Japan.

AIM: To assess the impact of breast-cancer treatment on fertility. METHODS: We conducted a retrospective, case-based survey of treatments administered for infertility and pregnancy outcomes after patients underwent treatment for breast cancer. Surveys were distributed to breast oncology facilities and reproductive endocrinology and infertility (REI) facilities. RESULTS: As high as 60% of the pregnancies in women under the age of 35 years occurred spontaneously. Additionally, the fertility rates decreased as age increased (under 35 years of age: 40%, 35-39 years of age: 21%, 40-44 years of age: 10%, respectively). In women who became pregnant after treatment for breast cancer, conception was achieved within 1 to 3 years after beginning to try for pregnancy. CONCLUSIONS: After treatment for breast cancer, women can expect spontaneous pregnancy, especially if they are under 35 years of age. It is important for patients 35 years of age and older to commence assisted reproductive technology in a timely manner when pursuing fertility after treatment for breast cancer.

Immunohistochemical comparison of three programmed death-ligand 1 (PD-L1) assays in triple-negative breast cancer.

BACKGROUND: Triple-negative breast cancer (TNBC) is the most aggressive type of breast cancer. A recent study demonstrated the efficacy of anti-PD-L1 (anti-programmed death ligand-1) immunotherapy in patients with TNBC. However, the identification of TNBC patients who may benefit from immunotherapy is a critical issue. Several assays have been used to evaluate PD-L1 expression, and a few studies comparing PD-L1 expression using various primary antibodies in TNBC tissues have been reported. However, the expression profiles of the PD-L1 using the 73-10 assay have not yet been analyzed in TNBC tissues. METHODS: We analyzed the PD-L1 immunohistochemical profiles of 62 women with TNBC using the 73-10, SP142 (companion diagnostic for atezolizumab), and E1L3N assays. PD-L1 expression on immune cells (ICs) and tumor cells (TCs) was also evaluated, and PD-L1 positivity was defined as a PD-L1-expressing ICs or TCs ≥ 1%. RESULTS: The expression rates of PD-L1 were 79.0%, 67.7%, and 46.8% on ICs, and 17.7%, 6.5%, and 12.9% on TCs using the 73-10, SP142, and E1L3N assays, respectively. The concordance rates between the 73-10 and SP142 assays were 85.5% (on ICs) and 88.7% (on TCs), respectively, and substantial agreement on ICs (coefficient 0.634) and moderate agreement (coefficient 0.485) on TCs were noted. Sample age and tumor diameter did not influence the ratio of PD-L1 expression among the assays. CONCLUSIONS: The positive rate on ICs and TCs of the 73-10 assay was higher than that of the SP 142 and E1L3N assays. Although substantial agreement on ICs and moderate agreement on TCs between the 73-10 and SP142 assays was noted in the present cohort, further studies are needed to clarify the PD-L1 expression status using various primary antibodies in a larger patient population. This would lead to the establishment of an effective evaluation method to assess the predictive value of anti-PD-L1 immunotherapy.

Immunohistochemical analysis of CD155 expression in triple-negative breast cancer patients.

INTRODUCTION: CD155 is an immune checkpoint protein. Its overexpression is an indicator of poor prognosis in some types of cancer. However, the significance of CD155 expression in patients with triple-negative breast cancer, and the relationship between CD155 and programmed death-ligand 1 (PD-L1) expression, have not yet been analyzed in detail. METHODS: Using immunohistochemical staining and tissue microarrays, we analyzed the expression profiles of CD155 and PD-L1 in 61 patients with triple-negative breast cancer. Relapse-free survival and overall survival rates were compared according to CD155 expression. The correlation between CD155 expression and clinicopathological factors, including PD-L1 expression (using SP142 and 73-10 assays), was also examined. RESULTS: CD155 expression was noted in 25 patients (41.0%) in this cohort. CD155 expression did not correlate with pathological stage, histological grade, Ki-67 labeling index, or stromal tumor-infiltrating lymphocytes. Only PD-L1 expression in tumor cells by SP142 assay significantly correlated with CD155 expression (p = 0.035); however, PD-L1 expression in tumor cells by 73-10 assay did not show a correlation (p = 0.115). Using the 73-10 assay, 59% of patients showed CD155 and/or PD-L1 expression in tumor cells. Moreover, using the SP142 assay, 63.3% of patients showed CD155 and/or PD-L1 expression in immune cells. CD155 expression did not correlate with either relapse-free survival or overall survival (p = 0.485 and 0.843, respectively). CONCLUSIONS: CD155 may be a novel target for antitumor immunotherapy. The results of this study indicate that CD155 may expand the pool of candidates with triple-negative breast cancer who could benefit from antitumor immunotherapy.

Prognostic significance of PD-L1-positive cancer-associated fibroblasts in patients with triple-negative breast cancer.

BACKGROUND: Cancer-associated fibroblasts (CAFs) are some of the most abundant components of the tumour microenvironment. A recent study suggested that in some cancers, CAFs express programmed death ligand 1 (PD-L1), which can act as a prognostic marker. The aim of this study was to investigate the clinicopathological significance of CAF PD-L1 expression in patients with triple-negative breast cancer (TNBC) and to identify the most suitable primary antibody for immunostaining for CAF PD-L1. METHODS: Immunohistochemical staining (primary antibodies of 73-10, SP142, and E1L3N) and tissue microarrays were used to analyse the expression profiles of PD-L1 in CAF in 61 patients with TNBC who underwent surgery. Overall survival (OS) was compared based on CAF PD-L1 expression, and the risk factors for OS were analysed. The relationship between clinicopathological parameters and survival was also examined. RESULTS: Thirty-four (55.7%) patients were positive for CAF PD-L1 (73-10) expression. Compared with CAF PD-L1 negativity, there was a significant correlation between CAF PD-L1 positivity and better OS (p = 0.029). CAF PD-L1 expression, evaluated using SP-142 or E1L3N, did not correlate with OS. CAF PD-L1-positivity (73-10) correlated significantly with better prognosis in multivariate analyses (hazard ratio: 0.198; 95% confidence interval: 0.044-0.891; p = 0.035). CONCLUSIONS: CAF PD-L1 expression is a novel marker for a better prognosis of patients with TNBC, and the 73-10 assay may be suitable for immunostaining CAF PD-L1.

Presence of myxoid stromal change and fibrotic focus in pathological examination are prognostic factors of triple-negative breast cancer: Results from a retrospective single-center study.

BACKGROUND: Stromal reaction is an important prognostic factor in several cancers, and the presence of myxoid change was assessed as a poor prognostic factor in colorectal cancer. However, the prognostic significance of myxoid change in triple-negative breast cancer (TNBC) remains unknown. This study aimed to determine the prognostic significance of myxoid change and fibrotic focus (FF), which is a fibrotic area within the tumor and considered a poor prognostic indicator in patients with TNBC. METHODS: We enrolled 62 patients with TNBC and reviewed the surgically resected specimens to evaluate myxoid change and FF in the tumor using previously outlined criteria. We evaluated tumor-infiltrating lymphocytes (TILs) using hematoxylin and eosin slides. Overall survival (OS) and relapse-free survival (RFS) were compared based on the presence of myxoid change and/or FF, and the risk factors for RFS were analyzed. RESULTS: Myxoid change and FF were observed in 25.8% and 33.9% of specimens, respectively. Based on stromal lymphocyte infiltration, 19 patients (30.6%) had high TILs, while the remaining 43 patients (69.4%) had low/intermediate TILs. Presence of myxoid change was significantly correlated with poor OS and RFS (p = 0.040 and 0.031, respectively). FF was also significantly correlated with poor OS and RFS (p = 0.012 and 0.028, respectively). The combination of myxoid change and FF was an independent and poor prognostic factor according to the multivariate analysis (HR 11.61; 95% CI 1.027-131.2; p = 0.048). Presence of myxoid change and FF were significantly associated with low/intermediate TILs in the stroma (p = 0.013). CONCLUSIONS: Histopathological assessment of myxoid change and FF in TNBC may be a useful, practical, and easily assessable method for predicting prognosis in patients with TNBC, which should be confirmed in larger prospective studies. Diagnostic criteria for the establishment of myxoid change and FF in TNBC must be established, and their underlying molecular events must be clarified.

Adjuvant S-1 plus endocrine therapy for oestrogen receptor-positive, HER2-negative, primary breast cancer: a multicentre, open-label, randomised, controlled, phase 3 trial.

BACKGROUND: Oral fluoropyrimidines, such as S-1, have been shown to have a role in controlling disease progression in metastatic breast cancer. We examined adjuvant treatment with S-1 in patients with oestrogen receptor (ER)-positive and HER2-negative primary breast cancer. METHODS: We did a multicentre, open-label, randomised, controlled, phase 3 trial in 139 sites (137 hospitals and two clinics). Eligible patients were women aged 20-75 years with histologically diagnosed stage I to IIIB invasive breast cancer (intermediate to high risk of recurrence). Patients were temporarily registered at participating institutions and biopsy or surgical samples were collected and sent for central pathological assessment. Patients received 5 years of standard adjuvant endocrine therapy (selective oestrogen receptor modulators with or without ovarian suppression and aromatase inhibitors) with or without 1 year of S-1. Oral S-1 80-120 mg/day was administered twice a day for 14 days with 7 days off. Randomisation (1:1) using the minimisation method was done with six stratification factors (age, axillary lymph node metastasis at surgery or sentinel lymph node biopsy, preoperative or postoperative (neoadjuvant or adjuvant) chemotherapy, preoperative endocrine therapy, proportion of ER-positive cells, and study site). The primary endpoint was invasive disease-free survival, in the full analysis set (all randomly assigned patients, excluding those with significant protocol deviations). The safety analysis set consisted of all patients who received at least one dose of study treatment. Here, we report the results from the interim analysis at the data cutoff date Jan 31, 2019. This trial is registered with Japan Registry of Clinical Trials, jRCTs051180057, and the University hospital Medical Information Network, UMIN000003969. FINDINGS: Between Feb 1, 2012, and Feb 1, 2016, 1930 patients were enrolled in the full analysis set, 957 (50%) received endocrine therapy plus S-1 and 973 (50%) received endocrine therapy alone. Median follow-up was 52·2 months (IQR 42·1-58·9). 155 (16%) patients in the endocrine therapy alone group and in 101 (11%) patients in the endocrine therapy plus S-1 group had invasive disease-free survival events (hazard ratio 0·63, 95% CI 0·49-0·81, p=0·0003). As the primary endpoint was met at interim analysis, the trial was terminated early. The most common grade 3 or worse adverse events were decreased neutrophil count (72 [8%] of 954 patients in the endocrine therapy plus S-1 group vs seven [1%] of 970 patients in the endocrine therapy alone group), diarrhoea (18 [2%] vs none), decreased white blood cells (15 [2%] vs two [<1%]), and fatigue (six [<1%] vs none). Serious adverse events were reported in nine (1%) of 970 patients in the endocrine therapy alone group and 25 (3%) of 954 patients in the endocrine therapy plus S-1 group. There was one (<1%) possible treatment-related death in the endocrine therapy plus S-1 group due to suspected pulmonary artery thrombosis. INTERPRETATION: These data suggest that this combination of S-1 with endocrine therapy could be a potential treatment option for this intermediate and high-risk group of patients with ER-positive, HER2-negative primary breast cancer. FUNDING: Public Health Research Foundation (Japan), Taiho Pharmaceutical.

Downregulated ATP6V1B1 expression acidifies the intracellular environment of cancer cells leading to resistance to antibody-dependent cellular cytotoxicity.

Among several mechanisms for the resistance of human epidermal growth factor receptor 2-overexpressing (HER2 +) cancer cells to trastuzumab, little is known regarding the mechanism underlying the resistance to trastuzumab-mediated antibody-dependent cellular cytotoxicity (ADCC). Cell death due to ADCC is caused by apoptosis of target cells induced by granzymes released from natural killer cells. Because optimal granzyme physiological activity occurs at neutral pH, we assumed that the pH of the intracellular environment influences the cytotoxic effects of granzymes. We established ADCC-resistant cells and compared them with wild-type cells in terms of the expression of intracellular pH-regulating genes. The expression of ATP6V1B1, which encodes a component of vacuolar ATPases, was downregulated in the ADCC-resistant cells. Thus, to functionally characterize ATP6V1B1, we used a CRISPR/Cas9 system to generate ATP6V1B1-knockout SKBR3 and JIMT-1 cells (both HER2 + human breast cancer cell line). The resulting cells exhibited significantly less ADCC than the control SKBR3 and JIMT-1 cells. The intracellular pH of the ATP6V1B1-knockout SKBR3 and JIMT-1 cells was significantly lower than control SKBR3 and JIMT-1cells. An analysis of granzyme dynamics during the ADCC reaction in cancer cells revealed that granzymes degraded intracellularly in the control SKBR3 and JIMT-1 cells and accumulated in ATP6V1B1-knockout cells, but were not cytotoxic. These findings suggest that decreased vacuolar ATPase activity alters the cytoplasmic pH of cancer cells to create an environment that is less suitable for granzyme bioactivity, which adversely affects the induction of apoptosis of cancer cells by NK cells.