Changes in cell-free DNA after short-term palbociclib and fulvestrant treatment for advanced or metastatic hormone receptor-positive and human epidermal growth factor 2-negative breast cancer.

PURPOSE: Here, we investigated the potential predictive and elucidating efficacy of cell-free DNA (cfDNA) changes on clinical outcomes and biological effects, respectively, after short-term palbociclib and fulvestrant treatment for patients with hormone receptor (HR)-positive and human epidermal growth factor 2 (HER2)-negative advanced or metastatic breast cancer (ABC). METHODS: In this secondary analysis of the Japan Breast Cancer Research Group-M07 (FUTURE) trial, blood cfDNA was obtained before palbociclib treatment and on day 15 of cycle one (28-day cycle). Target enrichment was performed using next-generation sequencing; progression-free survival (PFS) was compared based on cfDNA changes between baseline and day 15 of cycle one after combination therapy. RESULTS: Fifty-six patients (112 paired blood samples) were examined. The median follow-up time was 8.9 months. PIK3CA (30.4%, 17/56), FOXA1 (30.4%, 17/56), and ESR1 (28.6%, 16/56) were most frequently mutated at baseline. The number of mutated genes was significantly decreased on day 15 compared with that at baseline (paired t test: P value = 0.025). No significant difference was observed in PFS (decrease group, 7.9 m vs the others, 9.3 m; log-rank P value = 0.75; hazard ratio, 1.13; 95% confidence interval, 0.53-2.41). Among patients without previous aromatase inhibitor treatment (n = 15), three (20%) had ESR1 mutations after progression to fulvestrant. CONCLUSION: No significant association was observed between changes in mutated genes after short-term palbociclib and fulvestrant treatment and disease progression; a significant reduction in cfDNA mutation level was observed on day 15 of cycle one. Clinical meanings of cfDNA should be investigated in the future trials.

Prognostic value of the 21-Gene Breast Recurrence Score® assay for hormone receptor-positive/human epidermal growth factor 2-negative advanced breast cancer: subanalysis from Japan Breast Cancer Research Group-M07 (FUTURE trial).

PURPOSE: This study aimed to determine whether the 21-Gene Breast Recurrence Score® assay from primary breast tissue predicts the prognosis of patients with hormone receptor-positive and human epidermal growth factor 2-negative advanced breast cancers (ABCs) treated with fulvestrant monotherapy (Group A) and the addition of palbociclib combined with fulvestrant (Group B), which included those who had progression in Group A from the Japan Breast Cancer Research Group-M07 (FUTURE trial). METHODS: Progression-free survival (PFS) and overall survival (OS) were compared using the log-rank test and Cox regression analysis based on original recurrence score (RS) categories (Low: 0-17, Intermediate: 18-30, High: 31-100) by treatment groups (A and B) and types of ABCs (recurrence and de novo stage IV). RESULTS: In total, 102 patients [Low: n = 44 (43.1%), Intermediate: n = 38 (37.5%), High: n = 20 (19.6%)] in Group A, and 45 in Group B, who had progression in Group A were analyzed. The median follow-up time was 23.8 months for Group A and 8.9 months for Group B. Multivariate analysis in Group A showed that low-risk [hazard ratio (HR) 0.15, 95% confidence interval (CI) 0.04-0.53, P = 0.003] and intermediate-risk (HR 0.22, 95% CI 0.06-0.78) with de novo stage IV breast cancer were significantly associated with better prognosis compared to high-risk. However, no significant difference was observed among patients with recurrence. No prognostic significance was observed in Group B. CONCLUSION: We found a distinct prognostic value of the 21-Gene Breast Recurrence Score® assay by the types of ABCs and a poor prognostic value of the high RS for patients with de novo stage IV BC treated with fulvestrant monotherapy. Further validations of these findings are required.

Phase II trial of biweekly administration with eribulin after three cycles of induction therapy in hormone receptor-positive, HER2-negative metastatic breast cancer (JACCRO BC-03).

PURPOSE: Metastatic breast cancer (MBC) is usually incurable; treatment aims to maximize patients' function and quality of life (QOL). Eribulin is a standard treatment in patients with MBC pretreated with anthracycline and taxane; however, the best administration schedule is unknown. METHODS: In this prospective phase II trial of patients with luminal MBC, we administered biweekly eribulin to patients who completed a three-cycle induction treatment. RESULTS: Sixty patients with hormone-receptor-positive and HER2-negative MBC were enrolled; 40 obtained stable disease (SD) or better efficacy after induction therapy, after which they were switched to biweekly maintenance administration. The median progression-free survival (PFS) in patients who switched to maintenance therapy was 15.21 weeks (95% CI 9.71-22.14), starting on the first day of maintenance therapy. Overall survival (OS) in patients who switched to maintenance therapy was 21.39 months (95% CI 18.89-32.89). PFS and OS in the whole population starting from the registration date were 19.00 weeks (95% CI 17.00-25.00) and 21.52 months (95% CI 16.23-24.25), respectively. PFS from the enrollment date for patients who received maintenance therapy was 25.29 weeks (95% CI 19.14-32.14). Patients who achieved complete response or partial response during induction therapy had significantly longer PFS compared to patients with SD. CONCLUSION: The efficacy of biweekly administration of eribulin at maintenance was nonsignificant. However, less frequent visits are convenient, and reduced dose intensity improves safety. Biweekly administration, besides dose reduction, could be an acceptable option for patients who are unable to maintain a standard regimen.

Fulvestrant plus palbociclib in advanced or metastatic hormone receptor-positive/human epidermal growth factor receptor 2-negative breast cancer after fulvestrant monotherapy: Japan Breast Cancer Research Group-M07 (FUTURE trial).

PURPOSE: The combination of cyclin-dependent kinase 4/6 inhibitors and endocrine therapy is a standard treatment for hormone receptor (HR)-positive/human epidermal growth factor receptor 2 (HER2)-negative metastatic breast cancer (MBC); however, their toxicities and financial burden are major issues, especially for prolonged treatment. We investigated fulvestrant plus palbociclib in patients with HR-positive MBC resistant to fulvestrant monotherapy. METHODS: Patients who initially received fulvestrant as their first- or second-line endocrine therapy were assigned to group A. Patients with disease progression during fulvestrant monotherapy who subsequently received fulvestrant plus palbociclib were assigned to group B. The primary endpoint was progression-free survival (PFS1) in group B. We set the threshold median PFS of 5 months (null hypothesis). RESULTS: Between January 2018 and February 2020 we enrolled 167 patients in group A (January 2018-February 2020) from 55 institutions, of whom 72 subsequently received fulvestrant plus palbociclib and were enrolled in group B. The median follow-up was 23.8 and 8.9 months in groups A and B, respectively. The median PFS in group B (combination therapy) was 9.4 (90% confidence interval [CI]: 6.9-11.2) months (p < 0.001). This was 25.7 (90% CI: 21.2-30.3) months in group A (fulvestrant monotherapy). The TTF in group B was 7.2 (90% CI: 5.5-10.4) months. In the post-hoc analysis, the median PFS1 in group B among patients with longer-duration fulvestrant monotherapy (> 1 year) was longer than that of patients with shorter-duration monotherapy (≤ 1 year) (11.3 vs. 7.6 months). No new toxicities were observed. CONCLUSION: Our findings suggest that palbociclib plus fulvestrant after disease progression despite fulvestrant monotherapy is potentially safe and effective in patients with HR-positive/HER2-negative advanced MBC.

Efficacy and exploratory biomarker analysis of entinostat plus exemestane in advanced or recurrent breast cancer: phase II randomized controlled trial.

BACKGROUND: We aimed to confirm the efficacy and safety of the oral histone deacetylase inhibitor entinostat in Japanese patients with hormone receptor-positive advanced/recurrent breast cancer and to explore potential biomarkers. METHODS: This phase II, double-blind, randomized, placebo-controlled trial (ClinicalTrials.gov; NCT03291886) was conducted at 28 Japanese sites (September 2017-July 2020; interim analysis cutoff: April 2019). Patients with progression/relapse following non-steroidal aromatase inhibitors were randomized 1:1 to entinostat (5 mg/week) or placebo, plus exemestane (25 mg/day). Primary endpoint was progression-free survival; secondary endpoints included overall survival and safety. Exploratory biomarker outcomes included lysine acetylation, immune cell profiles, estrogen receptor 1 mutations and plasma chemokines. RESULTS: Of 133 randomized patients, 131 (65 entinostat, 66 placebo) who received study drug were analyzed. Median (95% confidence interval) progression-free survival was 5.8 (3.2-7.8) months for entinostat and 3.3 (3.1-5.8) months for placebo (hazard ratio [95% confidence interval]: 0.75 [0.50 - 1.14]; P = 0.189). Median overall survival was not reached in either group. Entinostat tended to prolong progression-free survival in patients aged ≥65 years, not endocrine resistant, or with estrogen receptor 1 Y537S mutation. Candidate biomarkers of efficacy (progression-free survival) included lysine acetylation in CD3+ cells, plasma interferon gamma-induced protein 10, dendritic cell CD86 expression, and CD4+ cell expression of human leukocyte antigen-DR and inducible T-cell co-stimulator. Safety was similar to non-Japanese populations; however, seven entinostat-treated patients (10.8%) had reversible lung injury. CONCLUSIONS: In Japanese patients, the safety of entinostat plus exemestane was acceptable and progression-free survival was prolonged, although not significantly. Exploratory analyses identified potential biomarkers, including lysine acetylation, of efficacy.

Serial circulating tumor DNA monitoring of CDK4/6 inhibitors response in metastatic breast cancer.

Cyclin-dependent kinase 4/6 inhibitors (CDK4/6i) significantly improve progression-free survival and have become the standard therapy for estrogen receptor-positive/human epidermal growth factor receptor 2-negative metastatic breast cancer patients. Treatment surveillance by radiological imaging has some limitations in detection and repeated biopsy genomic profiling is not clinically feasible. Serial circulating tumor DNA (ctDNA) analysis may provide insights into treatment response. Here we performed serial ctDNA analysis (n = 178) on 33 patients. Serial ctDNA analysis identified disease progression with sensitivity of 75% and specificity of 92%. In eight of 12 patients (61%) responding to CDK4/6i who eventually developed progressive disease, serial sampling every 3 or 6 months captured the initial rise of ctDNA with an average lead time of 3 months. In three of eight patients that did not respond to CDK4/6i (progressive disease at first radiological assessment, 3 months), biweekly sequencing within the first cycle of CDK4/6i treatment (1 month) detected sustained ctDNA levels (≥0.2% variant allele frequency), with lead time of 2 months. Serial ctDNA analysis tracked RECIST response, including clinically challenging scenarios (bone metastases or small-sized target lesions), as well as detecting acquired genetic alterations linked to CDK4/6i resistance in the G1 to S transition phase. Circulating tumor DNA analysis was more sensitive than carcinoembryonic antigen or cancer antigen 15-3 serum tumor markers at monitoring tumor response to CDK4/6i treatment. Our findings indicated the possible clinical utility of serial ctDNA analysis for earlier progressive disease detection and real-time monitoring of CDK4/6i response.

Trastuzumab and fulvestrant combination therapy for women with advanced breast cancer positive for hormone receptor and human epidermal growth factor receptor 2: a retrospective single-center study.

BACKGROUND: Trastuzumab and fulvestrant combination therapy is one of the treatment options for patients with hormone receptor- and human epidermal growth factor receptor 2 (HER2)-positive metastatic breast cancer; however, there are limited studies evaluating the efficacy of this combination therapy. METHODS: We retrospectively reviewed the data of women with hormone receptor- and HER2-positive metastatic breast cancer who received trastuzumab and fulvestrant combination therapy between August 1997 and August 2020 at the Cancer Institute Hospital. The primary endpoint of this study was progression-free survival, and the secondary endpoints were response rate, overall survival and safety. RESULTS: We reviewed the data of 1612 patients with recurrent or metastatic breast cancer, of which 118 patients were diagnosed with hormone receptor- and HER2-positive breast cancer. Of these, 28 patients who received trastuzumab and fulvestrant combination therapy were eligible for this study. The median treatment line for advanced breast cancer was 6 (range, 1-14), the median progression-free survival was 6.4 months (95% confidence interval [CI], 3.46-8.17), and the median overall survival was 35.3 months (95% CI, 20.0-46.7). Of the 28 patients, partial response was observed in 1 (4%), stable disease in 17 (61%), and progressive disease in 10 (36%) patients. The disease control rate was 64%. Adverse events of grade ≥ 3 were not observed. CONCLUSIONS: Trastuzumab and fulvestrant combination therapy showed moderate clinical efficacy and no severe toxicity after standard anti-HER2 treatment, which is a reasonable treatment option for patients with hormone receptor- and HER2-positive metastatic breast cancer. These data contribute to understanding the efficacy of trastuzumab and fulvestrant combination therapy as control data for further development of anti-HER2 agents plus hormone therapy.

Subgroup analysis of Japanese patients in a phase III randomized, controlled study of neoadjuvant atezolizumab or placebo, combined with nab-paclitaxel and anthracycline-based chemotherapy in early triple-negative breast cancer (IMpassion031).

BACKGROUND: In the global phase III IMpassion031 study, neoadjuvant atezolizumab plus nab-paclitaxel/anthracycline-based chemotherapy improved pathological complete response in patients with early stage triple-negative breast cancer. Here, we report primary analysis results from a subgroup of Japanese patients. METHODS: Patients with histologically documented, previously untreated, stage cT2-cT4, cN0-cN3, cM0 triple-negative breast cancer were randomized 1:1 to receive intravenous atezolizumab 840 mg or placebo every 2 weeks in combination with chemotherapy consisting of nab-paclitaxel intravenous 125 mg/m2 once a week, followed by doxorubicin intravenous 60 mg/m2 and cyclophosphamide intravenous 600 mg/m2 every 2 weeks. Patients then underwent surgery. Pathological complete response (ypT0/is ypN0) in the intention-to-treat and PD-L1-positive (≥1% PD-L1-expressing tumor-infiltrating immune cells) populations were co-primary endpoints. RESULTS: This subanalysis (data cutoff: 3 April 2020) included 36 patients from Japan (intention-to-treat; atezolizumab arm, n = 17; placebo arm, n = 19). Pathological complete response occurred in 41% (n = 7; 95% confidence interval, 18-67) of patients in the atezolizumab arm and 37% (n = 7; 95% confidence interval, 16-62) in the placebo arm. In the PD-L1-positive population, pathological complete response occurred in 50% (n = 5; 95% confidence interval, 19-81) of patients in the atezolizumab arm and 45% (n = 5; 95% confidence interval, 17-77) in the placebo arm. Treatment-related grade 3-4 adverse events occurred in 71% and 68% of patients in the respective arms. CONCLUSION: Atezolizumab added to neoadjuvant chemotherapy numerically improved pathological complete response versus placebo in this small exploratory analysis of Japanese patients with early stage triple-negative breast cancer, a trend directionally consistent with the global study results. No new safety signals were identified.

Impact of chemotherapy on cognitive functioning in older patients with HER2-positive breast cancer: a sub-study in the RESPECT trial.

PURPOSE: To investigate whether postoperative adjuvant trastuzumab plus chemotherapy negatively affected cognitive functioning during the post-chemotherapy period compared with trastuzumab monotherapy in older patients with HER2-positive breast cancer. METHODS: In the randomized RESPECT trial, women aged between 70 and 80 years with HER2-positive, stage I to IIIA invasive breast cancer who underwent curative operation were randomly assigned to receive either 1-year trastuzumab monotherapy or 1-year trastuzumab plus chemotherapy. Cognitive functioning was assessed using the Mini-Mental State Examination (MMSE) test at enrollment and 1 and 3 years after initiation of the protocol treatment. The primary outcome was change in the MMSE total score from baseline. Secondary outcomes included prevalence of suspected mild cognitive impairment (MMSE total score < 28) and suspected dementia (MMSE total score < 24). RESULTS: The analytical population consisted of 29 and 26 patients in the trastuzumab monotherapy and trastuzumab plus chemotherapy groups, respectively. The group differences in mean changes of the MMSE total score were 0.6 (95% confidence interval [CI] - 0.3 to 1.6) at 1 year and 0.9 (95% CI - 1.0 to 2.8) at 3 years (P = 0.136 for the group difference pooling the two visits). The prevalence of suspected mild cognitive impairment at 3 years was 41.7% in the trastuzumab monotherapy group and 28.6% in the trastuzumab plus chemotherapy group (P = 0.548). CONCLUSION: This randomized sub-study did not show worse cognitive functioning during the post-chemotherapy period with trastuzumab plus chemotherapy than with trastuzumab monotherapy in older patients with HER2-positive breast cancer. TRIAL REGISTRATION NUMBER: NCT01104935 (first posted April 16, 2010).

Clinical significance of gene mutation in ctDNA analysis for hormone receptor-positive metastatic breast cancer.

PURPOSE: In this study, we aim to investigate the mutation spectrum of circulating tumor DNA among hormone receptor-positive metastatic breast cancer (HR-MBC) patients using ultradeep targeted resequencing. In addition, we also evaluate the correlation of mutations detected from this study with progression-free survival (PFS). MATERIALS AND METHODS: A total of 56 HR-MBC patients were enrolled. Cell-free DNA (cfDNA) was extracted from plasma and sequenced by using Oncomine Breast cancer cfDNA assay in this study. RESULT: Concentration of cfDNA is correlated with a number of metastatic organs and serum CEA levels (Spearman's rank correlation p = 0.0018, p = 0.0015 respectively). Cases with high cfDNA levels (≥ 2.6 ng/µl of plasma) showed worse progression-free survival (PFS) and overall survival compared with cases with low cfDNA levels (p = 0.043 and 0.046, respectively). Among these patients, 29 patients (51.7%) have TP53 mutations, 12 patients (30.3%) have PIK3CA mutations, and 9 patients (16.0%) have ESR1 mutations. Acquisition of ESR1 mutation increased according to the lines of hormone therapy. In addition, patients with ESR1 mutation showed shorter PFS than those without mutation (log-rank p = 0.047). In the multivariate analysis, ESR1 mutation and cfDNA concentration were significant for PFS (p = 0.027 and 0.006, respectively). In conclusion, assessment of ESR1 mutation and cfDNA concentration could be useful in predicting prognosis for HR-MBCs.

Pattern of Tumor Shrinkage during Neoadjuvant Chemotherapy Is Associated with Prognosis in Low-Grade Luminal Early Breast Cancer.

Purpose To evaluate the association between tumor shrinkage patterns shown with magnetic resonance (MR) imaging during neoadjuvant chemotherapy (NAC) and prognosis in patients with low-grade luminal breast cancer. Materials and Methods This retrospective study was approved by the institutional review board and informed consent was obtained from all subjects. The low-grade luminal breast cancer was defined as hormone receptor-positive and human epidermal growth factor receptor 2-negative with nuclear grades 1 or 2. The patterns of tumor shrinkage as revealed at MR imaging were categorized into two types: concentric shrinkage (CS) and non-CS. Among 854 patients who had received NAC in a single institution from January 2000 to December 2009, 183 patients with low-grade luminal breast cancer were retrospectively evaluated for the development set. Another data set from 292 patients who had received NAC in the same institution between January 2010 and December 2012 was used for the validation set. Among these 292 patients, 121 patients with low-grade luminal breast cancer were retrospectively evaluated. Results In the development set, the median observation period was 67.9 months. Recurrence was observed in 31 patients, and 16 deaths were related to breast cancer. There were statistically significant differences in both the disease-free survival (DFS) and overall survival (OS) rates between patterns of tumor shrinkage (P < .001 and P < .001, respectively). Multivariate analysis demonstrated that the CS pattern had the only significant independent association with DFS (P = .001) and OS (P = .009) rate. In the validation set, the median follow-up period was 56.9 months. Recurrence was observed in 20 patients (16.5%) and eight (6.6%) deaths were related to breast cancer. DFS rate was significantly longer in patients with the CS pattern (72.8 months; 95% confidence interval [CI]: 69.9, 75.6 months) than in those with the non-CS pattern (56.0 months; 95% CI: 49.1, 62.9 months; P ≤ .001). The CS pattern was associated with an excellent prognosis (median OS, 80.6 months; 95% CI: 79.3, 81.8 months vs 65.0 months; 95% CI: 60.1, 69.8 months; P = .004). Multivariate analysis demonstrated that the CS pattern had the only significant independent association with DFS (P = .007) and OS (P = .037) rates. Conclusion The CS pattern as revealed at MR imaging during NAC had the only significant independent association with prognosis in patients with low-grade luminal breast cancer. © RSNA, 2017.

Predictive impact of absolute lymphocyte counts for progression-free survival in human epidermal growth factor receptor 2-positive advanced breast cancer treated with pertuzumab and trastuzumab plus eribulin or nab-paclitaxel.

BACKGROUND: Although peripheral blood-based parameters (PBBPs) are reported as prognostic indicators in patients with breast cancers, their utility has not been studied in human epidermal growth factor receptor 2 (HER2)-positive advanced breast cancer (ABC). Tumor-infiltrating lymphocytes (TILs) might be a predictive factor in patients with HER2-positive ABC treated with pertuzumab and trastuzumab (PT) plus docetaxel. We aimed to evaluate whether PBBPs could have predictive value in HER2-positive ABC treated with pertuzumab and trastuzumab (PT) combined with eribulin (ERI) or nab-paclitaxel (Nab-PTX). METHODS: Data from 51 patients included in two single-arm, phase II trials were included in this retrospective-prospective study; the ERI + PT (N = 30) and Nab-PTX + PT (N = 21) combinations were registered under clinical trials number UMIN000012375 and UMIN000006838, respectively. We assessed PBBPs using prospectively collected data and investigated the association with progression-free survival (PFS); we evaluated absolute lymphocyte count (ALC), neutrophil to lymphocyte ratio (NLR) and platelet to lymphocyte ratio (PLR). The cutoff values for ALC, NLR, and PLR were set at 1000 or 1500 cells/µL, 2, and 250, respectively. RESULTS: PFS was significantly improved in patients with ALC ≥1500/µL compared to those with ALC 1000-, <1500/µL or ALC < 1000/µL (P = 0.0106). High baseline ALC was significantly associated with improved PFS (≥1500/µL; hazard ratio [HR]: 0.3715; 95% confidence interval [CI]: 0.1735-0.7955; P = 0.0108). In contrast, improved PFS was not significantly associated with NLR or PLR. Improved PFS in patients with ALC ≥1500/µL was observed irrespective of visceral metastasis or chemotherapy regimen. CONCLUSIONS: Our results showed that baseline ALC was a predictive factor for PFS in HER2-positive ABC treated with PT irrespective of combined chemotherapy regimen. Anti-tumor effects might be mediated not only by the tumor microenvironment, but also by systemic peripheral circulating lymphocytes. Baseline systemic parameters such as peripheral lymphocyte count might be beneficial in addition to disease extent for predicting the efficacy of PT treatment. TRIAL REGISTRATION: UMIN000012375 , registration date: 21NOV2013, and UMIN000006838 , registration date: 6DEC2011.

Prognostic significance of histological therapeutic effect in preoperative chemotherapy for breast cancer.

To establish a prognostic prediction system, we examined the relationships between prognosis and histological therapeutic effect or ypTNM classification in 258 breast cancer patients who received neoadjuvant chemotherapy. The case distribution according to therapeutic effect was nine patients (3.5%) with Grade 0, 169 (65.5%) with Grade 1, 58 (22.5%) with Grade 2, and 22 (8.5%) with Grade 3. The 5-year overall survival (OS) rate by therapeutic effect was 56% in Grade 0, 81% in Grade 1, 87% in Grade 2, and 96% in Grade 3. The higher the therapeutic effect the better the prognosis, with a significant difference among the groups (P = 0.008). The case distribution according to ypTNM classification was 20 patients (7.8%) with Stage 0, 83 (32.2%) with Stage I, 77 (29.8%) with Stage II, and 78 (30.2%) with Stage III. The 5-year OS rate by ypTNM classification was 95% in Stage 0, 94% in Stage I, 89% in Stage II, and 59% in Stage III. While prognosis was mostly comparable in Stages 0 and I, in the other stages it became significantly worse as residual cancer increased (P < 0.001). The prognosis of breast cancer patients with neoadjuvant chemotherapy can be predicted by histological therapeutic effect and staging classification of residual cancer.

Impact of immunohistological subtypes on the long-term prognosis of patients with metastatic breast cancer.

PURPOSE: Although improved long-term prognoses for patients with metastatic breast cancer (MBC) have been demonstrated, few reports address overall survival (OS) with sufficient follow-up. Furthermore, the relevance of immunohistological subtypes to OS in MBC has not been clarified. METHODS: We evaluated, retrospectively, the OS of patients who had been initiated on systemic therapy for MBC between 2000 and 2008. RESULTS: The subjects of this study were 527 patients with MBC treated by systemic therapy. The median survival time (MST) was 55.5 months. The MST for each immunohistological subtype was as follows: luminal, 59.9 months; luminal-HER2, not reached; triple-negative, 18.6 months; and HER2-enriched, 49.9 months. According to multivariate analysis, metastasis-free intervals of ≥2 years and treatment with anthracycline for MBC were predictive of better OS. The predictors of shorter OS included disease progression after first-line treatment for MBC, triple-negative, and all histological factors, except papillotubular carcinoma, with liver metastasis, and having three or more initial metastatic sites. CONCLUSIONS: The prognosis of the patients with MBC in this series was better than that reported before 2000, which is probably attributable to the use of novel, improved pharmacological agents. For example, luminal-HER2 tumors can be treated using both aromatase inhibitors and trastuzumab. Because of the lower toxicities, it is now possible to administer these agents for longer periods, resulting in better prognoses.

Oxidative DNA damage: Induction by fructose, in vitro, and its enhancement by hydrogen peroxide.

Sucrose and high-fructose corn syrup comprise nearly equal amounts of glucose and fructose. With the use of high-fructose corn syrup in the food industry, consumption of fructose, which may be a tumor promoter, has increased dramatically. We examined fructose-induced oxidative DNA damage in the presence of Cu(II), with or without the addition of H2O2. With isolated DNA, fructose induced Cu(II)-mediated DNA damage, including formation of 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG), to a greater extent than did glucose, and H2O2 enhanced the damage. In cultured human cells, 8-oxodG formation increased significantly following treatment with fructose and the H2O2-generating enzyme glucose oxidase. Fructose may play an important role in oxidative DNA damage, suggesting a possible mechanism for involvement of fructose in carcinogenesis.

Implementation of microsatellite instability testing for the assessment of solid tumors in clinical practice.

BACKGROUND: In Japan, microsatellite instability (MSI) testing for solid tumors was introduced in clinical practice in December 2018. Although immune checkpoint inhibitors (ICIs) are established standards of care for patients with MSI-high tumors, the status of implementing MSI testing in clinical practice remains unclear. METHODS: We retrospectively reviewed the medical records of patients with solid tumors who underwent MSI testing between January 2019 and December 2020 at our institution. RESULTS: In total, 1,052 MSI tests were performed in 1,047 patients. Regardless of specimen volume and condition, the MSI status was successfully determined in 1,041 (99.0%) tests, encompassing 27 tumor types (microsatellite stable [MSS] or MSI-low: n = 991 [95.2%] and MSI-high: n = 50 [4.8%]). Patients whose specimens were fixed with 20% neutral buffered formalin (NBF) and who had specimens with prolonged storage (98.4% and 95.4%) showed lower success rates than those whose specimens were fixed with 10% NBF and who had specimens with nonprolonged storage (100.0% and 99.6%), respectively. The prolonged turnaround time (TAT) in MSI-high cases (median TAT: 24 days) was a critical issue that directly resulted in treatment delay. Of the 50 patients with MSI-high tumors, 24 (48.0%) received ICIs and 34 (68.0%) were referred to the Department of Clinical Genetic Oncology where 6 (12.0%) patients were diagnosed with Lynch syndrome. CONCLUSIONS: MSI testing was successfully performed for various types of tumors and specimens in clinical practice. Our study results identified certain issues associated with the clinical implementation of MSI testing, including optimal specimen selection, extended TAT in MSI-high cases, and awareness of hereditary tumors.

Cost-Effectiveness of Trastuzumab With or Without Chemotherapy as Adjuvant Therapy in HER2-Positive Elderly Breast Cancer Patients: A Randomized, Open-Label Clinical Trial, the RESPECT Trial.

BACKGROUND AND OBJECTIVE: Trastuzumab is a standard care as adjuvant chemotherapy (AdjCT) for patients with human epidermal growth factor receptor 2 (HER2)-positive primary breast cancer (BC) in Japan. However, no reports have evaluated its economics for patients with HER2-positive BC over 70 years of age. The objective of this study was to evaluate the cost-effectiveness of HER2-targeted trastuzumab + chemotherapy in Japan, comparing it with trastuzumab monotherapy. METHODS: A three-state-partitioned survival model was developed to evaluate the cost-effectiveness of trastuzumab + chemotherapy versus trastuzumab monotherapy for AdjCT in elderly patients with HER2-positive BC. We derived the efficacy data, utilities, and costs of both arms from individual patient data in the RESPECT trial (NCT01104935) and published studies. The costs and quality-adjusted life years (QALYs) were discounted at 2% per annum using a payer perspective. The respective cost estimates were reported in 2019 Japanese Yen (JPY) or US dollars (US$). The primary outcome was the incremental cost-effectiveness ratio (ICER). We assured robustness with deterministic and probabilistic sensitivity analyses. RESULTS: The cost per patient for trastuzumab + chemotherapy was JPY 14.6 million (US$137,000), and their QALYs were 9.308, compared with JPY 14.2 million (US$131,000) and 9.101, respectively, for trastuzumab monotherapy. The ICER of trastuzumab + chemotherapy versus trastuzumab monotherapy was JPY 2.7 milllion/QALY (US$17,200/QALY). The ICER for trastuzumab with chemotherapy varied from "Dominant" to "Dominated" in one-way sensitivity analysis. CONCLUSIONS: The base-case analysis suggests that AdjCT with trastuzumab + chemotherapy is likely to be a cost-effective choice for patients with HER2-positive BC aged 70 years or older. However, the sensitivity analysis suggested uncertainty regarding the cost-effectiveness of trastuzumab + chemotherapy.

Phase 1 study of the liposomal formulation of eribulin (E7389-LF): Results from the breast cancer expansion cohort.

BACKGROUND: A liposomal formulation of eribulin, E7389-LF, may provide improved pharmacokinetics and allow increased access to tumour tissues. This expansion of a phase 1 study assessed the safety and efficacy of E7389-LF in patients with human epidermal growth factor receptor type 2-negative metastatic breast cancer. METHODS: Patients received E7389-LF 2.0 mg/m2 every three weeks. Tumour assessments were conducted every six weeks by the investigator by Response Evaluation Criteria in Solid Tumours v1.1. All adverse events were monitored and recorded. Serum biomarker assessments were conducted. RESULTS: Of 28 patients included, 75.0% had hormone receptor-positive breast cancer (HR+ BC) and 25.0% had triple-negative breast cancer (TNBC). The most common grade ≥3 treatment-related treatment-emergent adverse events included neutropenia (67.9%), leukopenia (42.9%), thrombocytopenia (32.1%), and febrile neutropenia (25.0%). Rates of neutropenia and febrile neutropenia were lower among patients who received prophylactic pegfilgrastim. Objective response rate was 35.7% (95% confidence interval [CI]: 18.6-55.9) for all patients and 42.9% (95% CI: 21.8-66.0) for patients with HR+ BC. Median progression-free survival was 5.7 months (95% CI: 3.9-8.3). The median overall survival was 18.3 months (95% CI: 13.2-not estimable). Among the 54 biomarkers assessed, 27, including 5 of 7 vascular markers, were significantly altered by E7389-LF treatment from baseline to any time point. CONCLUSION: E7389-LF was tolerable and favourable antitumour activity was observed, particularly in patients with HR+ BC. Prophylactic pegfilgrastim can be considered in patients at high risk for neutropenia and febrile neutropenia. GOV NUMBER: NCT03207672.

Assessment of a cancer genomic profile test for patients with metastatic breast cancer.

Comprehensive cancer genomic profile (CGP) tests are being implemented under Japanese universal health insurance system. However, the clinical usefulness of CGP test for breast cancer patients has not been evaluated. Of the 310 patients who underwent CGP testing at our institution between November 2019 and April 2021, 35 patients with metastatic breast cancer whose treatment strategy was discussed by our molecular tumor board within the study period were investigated after exclusion of 2 cases that could not be analyzed. The turn-around time, drug accessibility, and germline identification detection were evaluated. The subtype was luminal in 20 patients (57.1%), triple-negative in 12 patients (34.3%), and luminal-HER2 in 3 patients (8.6%). Actionable gene mutations were detected in 30 patients (85.7%), and 7 patients (20.0%) were recommended for clinical trial participation, with the drug administered to 2 patients (5.7%). Three patients (8.6%) died due to disease progression before the test results were disclosed. We report the results of an initial assessment of the utility of CGP testing for patients with metastatic breast cancer under Japanese universal health insurance system. Conducting CGP tests at a more appropriate time could provide patients with greater benefit from treatments based on their specific gene mutations.

Adjuvant trastuzumab without chemotherapy for treating early HER2-positive breast cancer in older patients: A propensity score-adjusted analysis of a prospective cohort study.

PURPOSE: To gauge the effects of treatment practices on prognosis for older patients with HER2-positive early breast cancer, particularly to determine whether adjuvant trastuzumab alone can offer benefit over no adjuvant therapy. This is a prospective cohort study which accompanies the RESPECT that is a randomized-controlled trial (RCT). METHODS: Patients who declined the RCT were treated based on the physician's discretion. We studied the 1) trastuzumab-plus-chemotherapy group, 2) trastuzumab-monotherapy group, and 3) non-trastuzumab group (no therapy or anticancer therapy without trastuzumab). The primary endpoint was disease-free survival (DFS), which was compared using the propensity-score method. Relapse-free survival (RFS) and health-related quality of life (HRQoL) were assessed. RESULTS: We enrolled 123 patients aged over 70 years (median: 74.5). Treatment categories were: trastuzumab-plus-chemotherapy group (n = 36, 30%), trastuzumab-monotherapy group (n = 52, 43%), and non-trastuzumab group (n = 32, 27%). The 3-year DFS was 96.7% in trastuzumab-plus-chemotherapy group, 89.2% in trastuzumab-monotherapy group, and 82.5% in non-trastuzumab group. DFS in non-trastuzumab group was lower than in trastuzumab-plus-chemotherapy and trastuzumab-monotherapy groups (propensity-adjusted hazard ratio; HR: 3.29; 95% CI: 1.15-9.39; P = 0.026). The RFS in non-trastuzumab group was lower than in trastuzumab-plus-chemotherapy and trastuzumab-monotherapy groups (propensity-adjusted HR = 7.80; 95% CI: 2.32-26.2, P < 0.0001). There were no significant intergroup differences in the proportions of patients showing HRQoL deterioration at 36 months (P = 0.717). CONCLUSION: Trastuzumab-treated patients had better prognoses than patients not treated with trastuzumab without deterioration of HRQoL. Trastuzumab monotherapy could be considered for older patients who reject chemotherapy.