Therapeutic use of granulocyte colony-stimulating factor (G-CSF) in patients with febrile neutropenia: a comprehensive systematic review for clinical practice guidelines for the use of G-CSF 2022 from the Japan Society of Clinical Oncology.

BACKGROUND: Febrile neutropenia represents a critical oncologic emergency, and its management is pivotal in cancer therapy. In several guidelines, the use of granulocyte colony-stimulating factor (G-CSF) in patients with chemotherapy-induced febrile neutropenia is not routinely recommended except in high-risk cases. The Japan Society of Clinical Oncology has updated its clinical practice guidelines for the use of G-CSF, incorporating a systematic review to address this clinical question. METHODS: The systematic review was conducted by performing a comprehensive literature search across PubMed, the Cochrane Library, and Ichushi-Web, focusing on publications from January 1990 to December 2019. Selected studies included randomized controlled trials (RCTs), non-RCTs, and cohort and case-control studies. Evaluated outcomes included overall survival, infection-related mortality, hospitalization duration, quality of life, and pain. RESULTS: The initial search yielded 332 records. Following two rounds of screening, two records were selected for both qualitative and quantitative synthesis including meta-analysis. Regarding infection-related mortality, the event to case ratio was 5:134 (3.73%) in the G-CSF group versus 6:129 (4.65%) in the non-G-CSF group, resulting in a relative risk of 0.83 (95% confidence interval, 0.27-2.58; p = 0.54), which was not statistically significant. Only median values for hospitalization duration were available from the two RCTs, precluding a meta-analysis. For overall survival, quality of life, and pain, no suitable studies were found for analysis, rendering their assessment unfeasible. CONCLUSION: A weak recommendation is made that G-CSF treatment not be administered to patients with febrile neutropenia during cancer chemotherapy. G-CSF treatment can be considered for patients at high risk.

Effectiveness of G-CSF in chemotherapy for digestive system tumors: a systematic review of the Clinical Practice Guidelines for the Use of G-CSF 2022 delineated by the Japan Society of Clinical Oncology.

BACKGROUND: Granulocyte colony-stimulating factor (G-CSF) reportedly reduces the risk of neutropenia and subsequent infections caused by cancer chemotherapy. Although several guidelines recommend using G-CSF in primary prophylaxis according to the incidence rate of chemotherapy-induced febrile neutropenia (FN), the effectiveness of G-CSF in digestive system tumor chemotherapy remains unclear. To address these clinical questions, we conducted a systematic review as part of revising the Clinical Practice Guidelines for the Use of G-CSF 2022 published by the Japan Society of Clinical Oncology. METHODS: This systematic review addressed two main clinical questions (CQ): CQ1: "Is primary prophylaxis with G-CSF effective in chemotherapy?", and CQ2: "Is increasing the intensity of chemotherapy with G-CSF effective?" We reviewed different types of digestive system tumors, including esophageal, gastric, pancreatic, biliary tract, colorectal, and neuroendocrine carcinomas. PubMed, Cochrane Library, and Ichushi-Web databases were searched for information sources. Independent systematic reviewers conducted two rounds of screening and selected relevant records for each CQ. Finally, the working group members synthesized the strength of evidence and recommendations. RESULTS: After two rounds of screening, 5/0/3/0/2/0 records were extracted for CQ1 of esophageal/gastric/pancreatic/biliary tract/colorectal/ and neuroendocrine carcinoma, respectively. Additionally, a total of 2/6/1 records were extracted for CQ2 of esophageal/pancreatic/colorectal cancer, respectively. The strength of evidence and recommendations were evaluated for CQ1 of colorectal cancer; however, we could not synthesize recommendations for other CQs owing to the lack of records. CONCLUSION: The use of G-CSF for primary prophylaxis in chemotherapy for colorectal cancer is inappropriate.

Prognostic value of serum tartrate­resistant acid phosphatase­5b for bone metastasis in patients with resectable breast cancer.

Bone metastasis significantly affects the quality of life of patients with metastatic breast cancer, and can shorten overall survival. Identifying patients with early-stage breast cancer at high risk for bone metastasis and preventing bone metastasis may lead to a better quality of life and prolonged survival. The present study investigated whether serum tartrate-resistant acid phosphatase-5b (TRACP-5b), a bone turnover marker, can be a prognostic factor for bone metastasis. Female patients who underwent resectable breast surgery between May 2002 and August 2006 were consecutively investigated. A total of 304 patients with a median follow-up of 3,722 days were retrospectively analyzed. TRACP-5b levels in sera prepared from patients' blood drawn preoperatively without any presurgical treatments were measured using an enzyme-linked immunosorbent assay. The cutoff of TRACP-5b levels, in order to separate patients into high and low TRACP-5b groups, was set at median (347 mU/dl). The associations of clinicopathological factors, including TRACP-5b, with bone metastasis-free interval (BMFI), which was defined as the duration between surgery and the diagnosis of bone metastasis at any time point, were examined. Multivariate analysis of various clinicopathological features revealed that lymph node metastasis and histological grade were independent factors associated with BMFI (P=0.017 and 0.030, respectively). In patients with node-positive breast cancer (n=114), a high TRACP-5b level and a high grade were significantly and independently associated with worse BMFI (log-rank P=0.041 and 0.011, respectively). In conclusion, these findings indicated that TRACP-5b may predict bone metastasis in patients with node-positive breast cancer.

Real-world progression-free survival and overall survival of palbociclib plus endocrine therapy (ET) in Japanese patients with hormone receptor-positive/human epidermal growth factor receptor 2-negative advanced breast cancer in the first-line or second-line setting: an observational study.

BACKGROUND: A recent large real-world study conducted in the United States reported the effectiveness of palbociclib plus aromatase inhibitor in HR+/HER2- advanced breast cancer (ABC). However, local clinical practice and available medical treatment can vary between Japan and Western countries. Thus, it is important to investigate Japanese real-world data. This observational, multicenter study (NCT05399329) reports the interim analysis of effectiveness of palbociclib plus ET as first-line or second-line treatment for HR+/HER2- ABC by estimating real-world progression-free survival (rwPFS) and overall survival (OS) in Japanese routine clinical practice. METHODS: Real-world clinical outcomes and treatment patterns of palbociclib plus ET were captured using a medical record review of patients diagnosed with HR+/HER2- ABC who had received palbociclib plus ET in the first-line or second-line treatment across 20 sites in Japan. The primary endpoint was rwPFS; secondary endpoints were OS, real-world overall response rate, real-world clinical benefit rate, and chemotherapy-free survival. RESULTS: Of the 677 eligible patients, 420 and 257 patients, respectively, had received palbociclib with ET as first-line and second-line treatments. Median rwPFS (95% confidence interval) was 24.5 months (19.9-29.4) for first-line and 14.5 months (10.2-19.0) for second-line treatment groups. Median OS was not reached in the first-line group and was 46.7 months (38.8-not estimated) for the second-line group. The 36-month OS rates for de novo metastasis, treatment-free interval (TFI) ≥ 12 months, and TFI < 12 months were 80.2% (69.1-87.7), 82.0% (70.7-89.3), and 66.0% (57.9-72.9), respectively. CONCLUSION: The addition of palbociclib to ET was effective for treating HR+/HER2- ABC in Japanese routine clinical practice.

Comparison between a single dose of PEG G-CSF and multiple doses of non-PEG G-CSF: a systematic review and meta-analysis from Clinical Practice Guidelines for the use of G-CSF 2022.

BACKGROUD: Granulocyte colony-stimulating factor (G-CSF) is widely used for the primary prophylaxis of febrile neutropenia (FN). Two types of G-CSF are available in Japan, namely G-CSF chemically bound to polyethylene glycol (PEG G-CSF), which provides long-lasting effects with a single dose, and non-polyethylene glycol-bound G-CSF (non-PEG G-CSF), which must be sequentially administrated for several days. METHODS: This current study investigated the utility of these treatments for the primary prophylaxis of FN through a systematic review of the literature. A detailed literature search for related studies was performed using PubMed, Ichushi-Web, and the Cochrane Library. Data were independently extracted and assessed by two reviewers. A qualitative analysis or meta-analysis was conducted to evaluate six outcomes. RESULTS: Through the first and second screenings, 23 and 18 articles were extracted for qualitative synthesis and meta-analysis, respectively. The incidence of FN was significantly lower in the PEG G-CSF group than in the non-PEG G-CSF group with a strong quality/certainty of evidence. The differences in other outcomes, such as overall survival, infection-related mortality, the duration of neutropenia (less than 500/µL), quality of life, and pain, were not apparent. CONCLUSIONS: A single dose of PEG G-CSF is strongly recommended over multiple-dose non-PEG G-CSF therapy for the primary prophylaxis of FN.

Perspectives for the clinical application of ctDNA analysis to breast cancer drug therapy.

Circulating tumor DNA (ctDNA) consists of DNA fragments released from cancer cells into the blood circulation with quick clearance. Analysis of ctDNA can enable real-time assessment of the presence of cancer cells and their genomic characteristics. Therefore, ctDNA is expected to be one of the most useful biomarkers for cancer. In recent years, several ultra-sensitive assays for ctDNA analysis have been developed, and many clinical trials are using these assays to investigate the efficacy of ctDNA-based therapeutic strategies. In the perioperative phase, real-time identification of minimal residual disease at the molecular level with ctDNA analysis can help evaluate the risk of recurrence to inform escalation or de-escalation of perioperative drug therapy. Many trials have examined whether therapeutic strategies using ctDNA analysis to predict treatment efficacy or resistance to molecular targeted agents can improve prognosis in metastatic breast cancer. In this review, we discuss the most recent ctDNA assays, the significance of introducing ctDNA assays to clinical practice, and the research on their application in perioperative and metastatic phases.

High HER2 Intratumoral Heterogeneity Is a Predictive Factor for Poor Prognosis in Early-Stage and Locally Advanced HER2-Positive Breast Cancer.

PURPOSE: Breast cancer tumors frequently have intratumoral heterogeneity (ITH). Tumors with high ITH cause therapeutic resistance and have human epidermal growth factor receptor 2 (HER2) heterogeneity in response to HER2-targeted therapies. This study aimed to investigate whether high HER2 heterogeneity levels were clinically related to a poor prognosis for HER2-targeted adjuvant therapy resistance in primary breast cancers. METHODS: This study included patients with primary breast cancer (n = 251) treated with adjuvant HER2-targeted therapies. HER2 heterogeneity was manifested by the shape of HER2 fluorescence in situ hybridization amplification (FISH) distributed histograms with the HER2 gene copy number within a tumor sample. Each tumor was classified into a biphasic grade graph (high heterogeneity [HH]) group or a monophasic grade graph (low heterogeneity [LH]) group based on heterogeneity. Both groups were evaluated for disease-free survival (DFS) and overall survival (OS) for a median of ten years of annual follow-up. RESULTS: Of 251 patients with HER2-positive breast cancer, 46 (18.3%) and 205 (81.7%) were classified into the HH and LH groups, respectively. The HH group had more distant metastases and a poorer prognosis than the LH group (DFS: p < 0.001 (HH:63% vs. LH:91% at 10 years) and for the OS: p = 0.012 (HH:78% vs. LH:95% at 10 years). CONCLUSIONS: High HER2 heterogeneity is a poor prognostic factor in patients with HER2-positive breast cancer. A novel approach to heterogeneity, which is manifested by the shape of HER2 FISH distributions, might be clinically useful in the prognosis prediction of patients after HER2 adjuvant therapy.

Optimal timing of prophylactic pegylated G-CSF after chemotherapy administration for patients with cancer: a systematic review and meta-analysis from Clinical Practice Guidelines for the use of G-CSF 2022.

INTRODUCTION: The timing of prophylactic pegylated granulocyte colony-stimulating factor (G-CSF) administration during cancer chemotherapy varies, with Day 2 and Days 3-5 being the most common schedules. Optimal timing remains uncertain, affecting efficacy and adverse events. This systematic review sought to evaluate the available evidence on the timing of prophylactic pegylated G-CSF administration. METHODS: Based on the Minds Handbook for Clinical Practice Guideline Development, we searched the PubMed, Ichushi-Web, and Cochrane Library databases for literature published from January 1990 to December 2019. The inclusion criteria included studies among the adult population using pegfilgrastim. The search strategy focused on timing-related keywords. Two reviewers independently extracted and assessed the data. RESULTS: Among 300 initial search results, only four articles met the inclusion criteria. A meta-analysis for febrile neutropenia incidence suggested a potential higher incidence when pegylated G-CSF was administered on Days 3-5 than on Day 2 (odds ratio: 1.27, 95% CI 0.66-2.46, p = 0.47), with a moderate certainty of evidence. No significant difference in overall survival or mortality due to infections was observed. The trend of severe adverse events was lower on Days 3-5, without statistical significance (odds ratio: 0.72, 95% CI 0.14-3.67, p = 0.69) and with a moderate certainty of evidence. Data on pain were inconclusive. CONCLUSIONS: Both Day 2 and Days 3-5 were weakly recommended for pegylated G-CSF administration post-chemotherapy in patients with cancer. The limited evidence highlights the need for further research to refine recommendations.

Effectiveness and safety of primary prophylaxis of granulocyte colony-stimulating factor during dose-dense chemotherapy for urothelial cancer: Clinical Practice Guidelines for the Use of G-CSF 2022.

Granulocyte colony-stimulating factor (G-CSF) decreases the incidence, duration, and severity of febrile neutropenia (FN); however, dose reduction or withdrawal is often preferred in the management of adverse events in the treatment of urothelial cancer. It is also important to maintain therapeutic intensity in order to control disease progression and thereby relieve symptoms, such as hematuria, infection, bleeding, and pain, as well as to prolong the survival. In this clinical question, we compared treatment with primary prophylactic administration of G-CSF to maintain therapeutic intensity with conventional standard therapy without G-CSF and examined the benefits and risks as major outcomes. A detailed literature search for relevant studies was performed using PubMed, Ichu-shi Web, and Cochrane Library. Data were extracted and evaluated independently by two reviewers. A qualitative analysis of the pooled data was performed, and the risk ratios with corresponding confidence intervals were calculated and summarized in a meta-analysis. Seven studies were included in the qualitative analysis, two of which were reviewed in the meta-analysis of dose-dense methotrexate, vinblastine, doxorubicin, and cisplatin (MVAC) therapy, and one randomized controlled study showed a reduction in the incidence of FN. Primary prophylactic administration of G-CSF may be beneficial, as shown in a randomized controlled study of dose-dense MVAC therapy. However, there are no studies on other regimens, and we made a "weak recommendation to perform" with an annotation of the relevant regimen (dose-dense MVAC).

Effectiveness and safety of primary prophylaxis of G-CSF during chemotherapy for prostate cancer, Japanese clinical guideline for appropriate use of G-CSF: clinical practice guidelines for the use of G-CSF 2022.

BACKGROUND: Docetaxel (DTX) is commonly used as a primary chemotherapy, and cabazitaxel (CBZ) has shown efficacy in patients who are DTX resistant. Primary prophylactic granulocyte colony stimulating factor (G-CSF) therapy is currently used with CBZ treatment in routine clinical care in Japan. METHODS: In this study, we performed a systematic review following the Minds guidelines to investigate the effectiveness and safety of primary prophylaxis with G-CSF during chemotherapy for prostate cancer and to construct G-CSF guidelines for primary prophylaxis use during chemotherapy. A comprehensive literature search of various electronic databases (PubMed, Cochrane Library, and Ichushi) was performed on January 10, 2020, to identify studies published between January 1990 and December 31, 2019 that investigate the impact of primary prophylaxis with G-CSF during CBZ administration on clinical outcomes. RESULTS: Ultimately, nine articles were included in the qualitative systematic review. Primary G-CSF prophylaxis during CBZ administration for metastatic castration-resistant prostate cancer was difficult to assess in terms of correlation with overall survival, mortality from infection, and patients' quality of life. These difficulties were owing to the lack of randomized controlled trials comparing patients with and without primary prophylaxis of G-CSF during CBZ administration. However, some retrospective studies have suggested that it may reduce the incidence of febrile neutropenia. CONCLUSION: G-CSF may be beneficial as primary prophylaxis during CBZ administration for metastatic castration resistant prostate cancer, and we made a "weak recommendation to perform" with an annotation of the relevant regimen.

Effectiveness and safety of primary prophylaxis with G-CSF for lung cancer: a systematic review and meta-analysis to develop clinical practice guidelines for the use of G-CSF 2022.

BACKGROUND: Granulocyte colony-stimulating factor (G-CSF) is commonly administered to cancer patients undergoing myelosuppressive chemotherapy, especially when incidence rate of febrile neutropenia (FN) surpasses 20%. While primary prophylaxis with G-CSF has been proven effective in preventing FN in patients with cancer, there is limited evidence regarding its efficacy in specifically, lung cancer. Our systematic review focused on the efficacy of G-CSF primary prophylaxis in lung cancer. METHODS: We extracted studies on non-small-cell lung cancer (NSCLC) and small-cell lung cancer (SCLC) using the PubMed, Ichushi Web, and Cochrane Library databases. Two reviewers assessed the extracted studies for each type of lung cancer and conducted quantitative and meta-analyses of preplanned outcomes, including overall survival, FN incidence, infection-related mortality, quality of life, and musculoskeletal pain. RESULTS: A limited number of studies were extracted: two on NSCLC and six on SCLC. A meta-analysis was not conducted owing to insufficient data on NSCLC. Two case-control studies explored the efficacy of primary prophylaxis with G-CSF in patients with NSCLC (on docetaxel and ramucirumab therapy) and indicated a lower FN frequency with G-CSF. For SCLC, meta-analysis of five studies showed no significant reduction in FN incidence, with an odds ratio of 0.38 (95% confidence interval 0.03-5.56, P = 0.48). Outcomes other than FN incidence could not be evaluated due to low data availability. CONCLUSION: Limited data are available on G-CSF prophylaxis in lung cancer. Primary prophylaxis with G-CSF may be weakly recommended in Japanese patients with NSCLC undergoing docetaxel and ramucirumab combination therapy.

The Japanese Breast Cancer Society Clinical Practice Guidelines for systemic treatment of breast cancer, 2022 edition.

The Japanese Breast Cancer Society (JBCS) Clinical Practice Guidelines for systemic treatment of breast cancer were updated to the 2022 edition through a process started in 2018. The updated guidelines consist of 12 background questions (BQs), 33 clinical questions (CQs), and 20 future research questions (FRQs). Multiple outcomes including efficacy and safety were selected in each CQ, and then quantitative and qualitative systematic reviews were conducted to determine the strength of evidence and strength of recommendation, which was finally determined through a voting process among designated committee members. Here, we describe eight selected CQs as important updates from the previous guidelines, including novel practice-changing updates, and recommendations based on evidence that has emerged specifically from Japanese clinical trials.

Evaluation of RASSF1A methylation in the lysate of sentinel lymph nodes for detecting breast cancer metastasis: A diagnostic accuracy study.

The restriction enzyme-based digital methylation-specific polymerase chain reaction (RE-dMSP) assay is useful for diagnosing sentinel lymph node (SN) metastasis in patients with breast cancer, by detecting tumor-derived methylated Ras association domain-containing protein 1 (RASSF1A). In addition, this assay has high concordance (95.0%) with one-step nucleic acid amplification (OSNA). The present study aimed to perform RE-dMSP using OSNA lysate from more patients and to re-evaluate its clinical usage. Overall, 418 SNs from 347 patients were evaluated using both OSNA and RE-dMSP. The concordance rate was 83.3% (348/418). RASSF1A methylation of the primary tumors was negative in 36 patients. When these patients were excluded, the concordance rate improved to 88.2% (330/374). Of the 79 OSNA-negative cases, 19 were RE-dMSP-positive, although all were positive for cytokeratin 19 expression in the primary tumor, suggesting that RE-dMSP can detect tumor-derived DNA with a higher sensitivity. The percent of methylated reference of the breast tumors showed a wide variety in the 16 OSNA-positive/RE-dMSP-negative cases, and such variability of methylation could have affected the results in these patients. In conclusion, although RE-dMSP can diagnose SN metastasis with high sensitivity and accuracy, and can be a supplementary tool to OSNA in breast cancer, RE-dMSP showed certain discordance with OSNA and critically depended on the absence or heterogeneity of DNA methylation in breast tumors. Further research is expected to develop an assay targeting other DNA alterations, such as mutations.

Real-world data analysis of perioperative chemotherapy patterns, G-CSF use, and FN status in patients with early breast cancer.

PURPOSE: This study aimed to describe perioperative chemotherapy patterns, granulocyte colony-stimulating factor (G-CSF) use, and febrile neutropenia (FN) status in patients with early breast cancer (EBC) using real-world data in Japan. METHODS: This retrospective observational study used anonymized claims data. The included patients were ≥ 18 years old, were female, and had breast cancer diagnosis and surgery records between January 2010 and April 2020. Measures included perioperative chemotherapy, G-CSF use (daily and primary prophylaxis [PP]), and FN and FN-related hospitalization (FNH), all examined annually. Perioperative chemotherapy was examined separately for human epidermal growth factor receptor 2-positive/negative (HER2±). A multivariate logistic regression was used to explore the factors associated with FNH. RESULTS: Of 32,597 patients, those with HER2 + EBC treated with anthracycline-based regimens followed by taxane + trastuzumab + pertuzumab increased since 2018, and those with HER2 - EBC treated with doxorubicin/epirubicin + cyclophosphamide followed by taxane and dose-dense regimens increased after 2014. The proportion of patients prescribed daily G-CSF declined after 2014, whereas that of pegfilgrastim PP increased. The incidence proportion of FN remained at approximately 24-31% from 2010 to 2020, while that of FNH declined from 14.5 to 4.0%. The odds of FNH were higher in those aged ≥ 65 years and lower with pegfilgrastim PP administration. CONCLUSION: Despite the increasing use of escalated regimens in the last 5-6 years, FNH continuously declined, and the odds of FNH were lower among patients treated with pegfilgrastim PP. These results may suggest the contribution of PP in part to suppressing FNH levels over the last 5-6 years.

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.

Detection of high-risk patients resistant to CDK4/6 inhibitors with hormone receptor-positive HER2-negative advanced and metastatic breast cancer in Japan (KBCSG-TR-1316).

BACKGROUND: Cyclin-dependent kinase 4/6 inhibitors (CDK4/6i) improve the prognosis of hormone receptor-positive HER2-negative advanced/metastatic breast cancer (HR+/HER2- mBC). However, some cancers show resistance to CDK4/6i and have a poor prognosis. The non-luminal disease score (NOLUS) was developed to predict non-luminal disease using immunohistochemical analysis. METHODS: The association between the efficacy of CDK4/6i and NOLUS was investigated by evaluating pathological and clinical data, including real-world progression-free survival (rw-PFS) and overall survival (OS). Real-world data of patients with HR+/HER2- mBC who received CDK4/6i therapy [palbociclib or abemaciclib] as first- or second-line endocrine treatments was obtained. NOLUS was calculated using the formula: NOLUS (0-100) = - 0.45 × estrogen receptor (ER) (%) - 0.28 × progesterone receptor (PR) (%) + 0.27 × Ki67(%) + 73, and the patients were divided into two groups: NOLUS-positive (≥ 51.38) and NOLUS-negative (< 51.38). RESULTS: Of the 300 patients, 28 (9.3%) were NOLUS-positive, and 272 (90.7%) were NOLUS-negative. The expression rates (%) of ER and PgR in NOLUS-positive patients were lower than those in NOLUS-negative patients (p < 0.001). Ki67 expression was higher in NOLUS-positive patients. There were statistically significant differences in prognosis (rw-PFS and OS) between the two groups. Moreover, NOLUS-negative patients showed statistically better rw-PFS with first-line therapy than second-line therapy. However, NOLUS-positive patients showed poor prognoses with both the first and second therapeutic lines, suggesting CDK4/6i inefficacy for NOLUS-positive patients. CONCLUSIONS: The efficacy and prognosis of CDK4/6i significantly differed between the NOLUS-positive and NOLUS-negative patients. This feasible method can predict patients with HR+/HER2- mBC resistant to CDK4/6i and help select a better therapeutic approach to overcome resistance.

Detection of Ultra-Rare ESR1 Mutations in Primary Breast Cancer Using LNA-Clamp ddPCR.

ESR1 mutations in breast cancer are one of the mechanisms of resistance to aromatase inhibitors. These mutations are common in metastatic breast cancer; however, these are rare in primary breast cancer. However, these data have been analyzed mainly in formalin-fixed, paraffin-embedded tissue; thus, rare mutations that may be present in primary breast cancer may be overlooked. In this study, we developed a highly sensitive mutation detection method called locked nucleic acid (LNA)-clamp droplet digital PCR (ddPCR) and validated it. The mutation detection sensitivity was substantiated to 0.003%. Then, we used this method to analyze ESR1 mutations in fresh-frozen (FF) tissues of primary breast cancer. cDNA extracted from the FF tissues of 212 patients with primary breast cancers were measured. Twenty-eight ESR1 mutations were found in twenty-seven (12.7%) patients. Sixteen (7.5%) patients had Y537S mutations and twelve (5.7%) had D538G mutations. Two mutations with a variant allele frequency (VAF) of ≥0.1% and twenty-six mutations with a VAF of <0.1% were found. By using this LNA-clamp ddPCR, this study demonstrated the presence of minor clones with a VAF of <0.1% in primary breast cancer.

Hypercalcemia affected in metastatic breast cancer patients without bone metastasis: report of three cases.

BACKGROUND: Since humoral hypercalcemia of malignancy (HHM) in breast cancer patients without bone metastasis is rare, the clinical features of this condition are not fully understood. CASE PRESENTATION: During the recent 12 years, 3602 patients were diagnosed with breast cancer in our institution, and only three patients developed HHM without bone metastasis. They were all recurrent breast cancer patients with visceral metastases including the lung and the liver. It took no more than 2 months since symptomatic onset to hospitalization because of hypercalcemia. The maximum serum calcium concentrations were 15.0 mg/dL or higher. All patients had symptoms related to hypercalcemia. Treatment of hypercalcemia including hydration, calcitonin, bisphosphonate, and diuretics was initially effective in the three patients. However, two of three cases were eventually fatal because of unsuccessful treatment of breast cancer. CONCLUSIONS: The common features of HHM without bone metastasis in breast cancer patients include acute onset, severe symptomatic hypercalcemia, and presence of visceral metastasis. Treatment of hypercalcemia decreased serum calcium level in a short period, while successful treatment of breast cancer was essential for a long-term management of HHM. This report provides a consideration to help elucidate the pathophysiology and medical care of breast cancer patients with HHM without bone metastasis.

Pertuzumab retreatment for HER2-positive advanced breast cancer: A randomized, open-label phase III study (PRECIOUS).

No standard options existed for human epidermal growth factor receptor 2 (HER2)-positive advanced breast cancer that progresses after second-line trastuzumab emtansine therapy before 2020. The purpose of this study was to examine the efficacy of pertuzumab retreatment after disease progression following pertuzumab-containing therapy for HER2-positive locally advanced or metastatic breast cancer for the first time. This randomized, open-label, multicenter phase III trial was undertaken in 93 sites in Japan. Eligible patients with HER2-positive breast cancer who had received pertuzumab, trastuzumab, and chemotherapy as first- and/or second-line therapy were randomly assigned (1:1) to: (i) pertuzumab, trastuzumab, and physician's choice chemotherapy (PTC), or (ii) trastuzumab and physician's choice chemotherapy (TC). The primary end-point was investigator-assessed progression-free survival (PFS). Between August 1, 2015 and December 31, 2018, 219 patients were randomized to PTC (n = 110) or TC (n = 109). Median follow-up was 14.2 months (interquartile range, 9.0-22.2), and median PFS was 5.3 months (95% confidence interval [CI], 4.0-6.6) with PTC and 4.2 months (95% CI, 3.2-4.8) with TC (stratified hazard ratio 0.76 [95% CI upper limit 0.967]; p = 0.022). Progression-free survival was improved by adding pertuzumab in all prespecified subgroups. The PTC arm showed a trend towards better overall survival and duration of response, but similar objective response and health-related quality of life. The incidence of treatment-related adverse events was similar between groups except for diarrhea. Pertuzumab retreatment contributes to disease control for HER2-positive locally advanced or metastatic breast cancer previously treated with pertuzumab-containing regimens.

Proton Pump Inhibitors Ameliorate Capecitabine-induced Hand-Foot Syndrome in Patients With Breast Cancer: A Retrospective Study.

BACKGROUND/AIM: Hand-foot syndrome (HFS) is the most common adverse event associated with capecitabine, and its pathogenesis is known to be associated with inflammation. Proton pump inhibitors (PPIs) reportedly exert anti-inflammatory effects; however, the impact of PPIs on capecitabine-induced HFS needs to be clarified in the clinical setting. In the present study, we retrospectively investigated the efficacy and safety of PPIs in patients with breast cancer receiving capecitabine. PATIENTS AND METHODS: We analyzed the effects of PPIs on the development of severe HFS (grade ≥2), progression-free survival (PFS), and overall survival (OS) in 195 patients who received capecitabine chemotherapy for breast cancer. RESULTS: In total, 50 patients (26%) were treated with PPIs, while 145 patients (74%) did not receive PPIs. The incidence of severe HFS was significantly lower in patients who received PPIs (18%) than in patients who did not receive PPIs (43%, p=0.001), and the discontinuation rate of capecitabine therapy due to HFS was also lower in patients receiving PPIs than in those who did not receive PPIs (p=0.003). Multivariate analysis revealed that concomitant PPIs use was an independent factor that significantly contributed to the prevention of severe HFS (odds ratio (OR)=0.265, p=0.003). Meanwhile, no significant difference in median PFS and OS values was observed between patients treated with and without PPIs. CONCLUSION: Concomitant use of PPIs could ameliorate capecitabine-induced HFS in patients with breast cancer.