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.

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.

Correction to: The Japanese Breast Cancer Society Clinical Practice Guidelines for systemic treatment of breast cancer, 2018 edition

A correction to this paper has been published: https://doi.org/10.1007/s12282-021-01252-x

The efficacy and safety of pertuzumab plus trastuzumab and docetaxel as a first-line therapy in Japanese patients with inoperable or recurrent HER2-positive breast cancer: the COMACHI study

PURPOSE

In the CLEOPATRA study of patients with human epidermal growth factor receptor 2 (HER2)-positive recurrent or metastatic breast cancer, the Japanese patient subgroup did not demonstrate the improved progression-free survival (PFS) of pertuzumab plus trastuzumab and docetaxel vs. placebo that was seen in the overall population. Therefore, COMACHI was conducted to confirm the efficacy and safety of this treatment regimen in this patient subgroup.

METHODS

This was a phase IV study of pertuzumab plus trastuzumab and docetaxel in Japanese patients with histologically/cytologically confirmed inoperable or recurrent HER2-positive breast cancer. All patients received pertuzumab, trastuzumab, and docetaxel intravenously every 3 weeks until disease progression/unacceptable toxicity. The primary endpoint was investigator-assessed PFS. Secondary endpoints were overall survival (OS), investigator-assessed objective response rate, and duration of response (DoR). Safety was also assessed.

RESULTS

At final analysis, median investigator-assessed PFS was 22.8 months (95% CI 16.9-37.5). From first dose, OS rate at 1 year was 97.7%; and at 2 and 3 years were 88.5% and 79.1%, respectively. Of the 118 patients with measurable disease at baseline, response rate was 83.9% (95% CI 77.3-90.5) and median investigator-assessed DoR was 26.3 months (95% CI 17.1-not evaluable). Treatment was well tolerated, with no new safety signals detected.

CONCLUSIONS

Our results suggest similar efficacy and safety for pertuzumab plus trastuzumab and docetaxel in Japanese patients compared with the overall population of CLEOPATRA, providing further support for this combination therapy as standard of care for Japanese patients with inoperable or recurrent HER2-positive breast cancer.

The Japanese Breast Cancer Society Clinical Practice Guidelines for systemic treatment of breast cancer, 2018 edition

Purpose

We present the English version of The Japanese Breast Cancer Society (JBCS) Clinical Practice Guidelines for systemic treatment of breast cancer, 2018 edition.

Methods

The JBCS formed a task force to update the JBCS Clinical Practice Guidelines, 2015 edition, according to Minds Handbook for Clinical Practice Guideline Development 2014. First, we set multiple outcomes for each clinical question (CQ). Next, quantitative or qualitative systematic review was conducted for each of the multiple outcomes, and the strength of recommendation for the CQ was taken into consideration during meetings, with the aim of finding a balance between benefit and harm. Finalized recommendations from each session were confirmed through discussion and voting at the recommendation decision meeting.

Results

The recommendations, the strength of recommendation and the strength of evidence were determined based on systemic literature reviews and the meta-analyses for each CQ.

Conclusion

The JBCS updated the Clinical Practice Guidelines for systemic treatment of breast cancer.

Electronic supplementary material

The online version of this article (10.1007/s12282-020-01085-0) contains supplementary material, which is available to authorized users.

Multicenter Observational Study of Fulvestrant 500 mg in Postmenopausal Japanese Women with Estrogen Receptor-Positive Advanced or Recurrent Breast Cancer after Prior Endocrine Treatment (SBCCSG29 Study)

BACKGROUND

Fulvestrant 500 mg has been an option for endocrine therapy for advanced or recurrent breast cancer after prior endocrine treatment since November 2011 in Japan. This study aimed to clarify the effectiveness and safety of fulvestrant 500 mg in clinical settings.

METHODS

This was a multicenter, both prospective and retrospective, observational study of 132 postmenopausal women (median age 66) with locally advanced or metastatic breast cancer, who had been treated with fulvestrant. Information from medical records was retrospectively obtained from 9 hospitals (Saitama Breast Cancer Clinical Study Group: SBCCSG) in Saitama prefecture, Japan, from October 2012 to April 2014. The primary end point was time to treatment failure (TTF). The secondary end points were overall survival (OS), objective response rate (ORR), clinical benefit rate (CBR), and adverse events (AE) (CTCAE ver. 4). The choice of subsequent therapy after fulvestrant was also evaluated.

RESULTS

The median TTF was 6.1 months. Median OS was 28.5 months (the starting date was the first day of fulvestrant). ORR was 12.9% and CBR was 45.5%. The most common AEs were injection site reactions (9.1%). The rate of grade 3 AE was only 2.3% (3/132). The number of patients who underwent subsequent therapy after fulvestrant were 54 (55.7%) receiving chemotherapy, 42 (43.3%) receiving non-fulvestrant endocrine therapy, and 1 (1%) receiving mammalian target of rapamycin inhibitor (mTORi) + endocrine therapy (ET).

CONCLUSION

Fulvestrant 500 mg is an effective and safe treatment for patients with advanced or recurrent breast cancer after prior endocrine treatment.

Relation between dexamethasone (DEX) usage, preventive trimetprim/sulfametoxazole (ST), and pneumocystis pneumonia (PCP) for patients with breast cancer receiving dose-dense AC followed by dose-dense paclitaxel (ddAC-ddP): Preplanned analysis of WJOG9016B

e12022

Background: PCP is rare complication of ddAC-ddP. DEX is plausible risk factor for PCP. Dose and duration of DEX against CINV is changing over time as other anti-emetic drugs (5HT3 RA, NK1 RA, and olanzapin) became available. Then DEX usage varies widely in each hospitals. ASCO/IDSA guideline recommends preventive ST for patients receiving 20 mg or more predonisone equivalents daily for more than one month, although evidence is lacking in patients receiving ddAC-ddP. This study is to investigate relation between DEX usage, preventive ST, and risk of PCP for patients receiving ddAC-ddP. Methods: This study is preplanned analysis of WJOG9016B (UMIN000024992) which investigated relative dose intensity of ddAC-ddP supported by 3.6 mg (approved dose in Japan) of pegfilgrastim. Eligible pts were HER2 negative PBC with stage I to IIIc, going to start ddAC-ddP and younger than 65 y.o.. DEX usage and preventive ST usage were discrete to treating physicians. Results: From Jan. 2017 to Jan. 2018, 92 pts were registered and 91 pts were in the FAS set, because one patients turned out be ineligible after registration. All patients received DEX for prevention of delayed CINV. Median total dose of DEX during ddAC was 112 mg (range; 80 to 212 mg), which was equal to 13.3 mg (9.52 mg–24.76 mg) predonisone equivalents daily. Only five of them (5.4%) received more than 20 mg predonisone equivalents daily. Twenty patients received preventive ST. Three patients developed PCP. None of them with preventive ST developed PCP (0%), whereas three of patients without ST developed PCP (4.2%). These three patients received total DEX dose during ddAC at 80 mg, 112 mg, and 112 mg, respectively. Conclusions: ST was highly effective for PCP prevention for patients receiving ddAC-ddP, if DEX used against delayed CINV. Without ST prevention, the risk of PCP was 4.2 %, which was higher than threshold (3.5%) proposed in ASCO/ IDSA guidelines. The threshold of steroid dose leading to the risk of PCP might be lower than 20 mg or more predonisone equivalents daily in patients receiving ddAC-ddP. Clinical trial information: UMIN000024992.

Abstract P5-12-17: Prognostic and predictive value of serum level of vascular endothelial growth factor-A in metastatic breast cancer patients treated with bevacizumab plus paclitaxel

Background

Several studies showed that first-line bevacizumab plus chemotherapy for HER2-negative metastatic breast cancer improves progression-free survival and tumor response rate but not overall survival. MERiDiAN trial evaluated plasma vascular endothelial growth factor-A (VEGF-A) prospectively as a predictive biomarker for bevacizumab efficacy in metastatic breast cancer. However, results of this trial do not support using baseline plasma VEGF-A to identify patients benefitting most from bevacizumab. We measured baseline serum VEGF-A level from stored blood samples of metastatic breast cancer patient with treated bevacizumab plus paclitaxel as fist-line and later line therapy, and evaluated a correlation between serum VEGF-A level and efficacy of bevacizumab and prognosis of breast cancer patients tread with bevacizumab, retrospectively.

Patients and methods

We examined blood samples from 57 metastatic breast cancer patients treated with bevacizumab and paclitaxel, after obtaining written informed consent. And, we evaluated a correlation between baseline serum VEGF-A level and time to treatment failure (TTF) and overall survival (OS). We also compared the serum VEGF-A level of response group (CR and PR) and that of non-response group (SD and PD).

Results

Baseline serum level of VEGF-A ranged from 80 to 2079 pg/ml. Cases of treatment line were as follows: first-line, 22 cases (38.6%); second line, 11 cases (19.3%) and third-line and the later line, 24 cases (42.1%). The cutoff identified by ROC curve analysis that was able to differentiate response group and non-response group in first-line setting was 360pg/ml for serum VEGF-A. And, we separated high serum VGEF-A group and low serum VEGF-A group of patients treated with bevacizumab plus paclitaxel.

In patients treated as first line therapy, median TTF was 4.0 months with high serum VGEF-A group versus 5.0 months with low serum VEGF-A group, and median OS was 12 months with high serum VGEF-A group versus 11months with low serum VEGF-A group. There were no significant differences in both TTF and OS in first line setting. In patients treated as second line and later line therapy, median TTF was 2.8 months with high serum VGEF-A group versus 7.1 months with low serum VEGF-A group, and median OS was 6.4 months with high serum VGEF-A group versus 12.7 months with low serum VEGF-A group. The prognosis of high serum VEGF-A group was significantly worse than that of low serum group in both TTF and OS.

The serum VEGF-A level of response group was tend to be higher than that of non-response group in first line setting, and was lower in second and later line setting. However, there were no significant differences.

Conclusion

In this study, serum VEGF-A cannot be a predictor for efficacy of bevacizumab plus paclitaxel as first line therapy for metastatic breast cancer patients. On the other hand, there was a possibility that high serum level of VEGF-A can be a poor prognostic factor in late line therapy setting of bevacizumab.

Citation Format: Tozuka K, Nagai SE, Matsumoto H, Hayashi Y, Kubo K, Tsuboi M, Sato A, Takai K, Wang X, Yamada Y, Inoue K. Prognostic and predictive value of serum level of vascular endothelial growth factor-A in metastatic breast cancer patients treated with bevacizumab plus paclitaxel [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P5-12-17.

A multi-national, randomised, open-label, parallel, phase III non-inferiority study comparing NK105 and paclitaxel in metastatic or recurrent breast cancer patients

Background

NK105 is a novel nanoparticle drug delivery formulation that encapsulates paclitaxel (PTX) in polymeric micelles. We conducted an open-label phase III non-inferiority trial to compare the efficacy and safety of NK105 and PTX in metastatic or recurrent breast cancer.

Methods

Patients were randomly assigned in a 1:1 ratio to receive either NK105 (65 mg/m²) or PTX (80 mg/m²) on days 1, 8 and 15 of a 28-day cycle. The primary endpoint was progression-free survival (PFS), with a non-inferiority margin of 1.215.

Results

A total of 436 patients were randomised and 211 patients in each group were included in the efficacy analysis. The median PFS was 8.4 and 8.5 months for NK105 and PTX, respectively (adjusted hazard ratio: 1.255; 95% confidence interval: 0.989–1.592). The median overall survival and overall response rates were 31.2 vs. 36.2 months and 31.6% vs. 39.0%, respectively. The two groups exhibited similar safety profiles. The incidence of peripheral sensory neuropathy (PSN) was 1.4% vs. 7.5% (≥Grade 3) for NK105 and PTX, respectively. The patient-reported outcomes of PSN were significantly favourable for NK105 (P < 0.0001).

Conclusions

The primary endpoint was not met, but NK105 had a better PSN toxicity profile than PTX.

Clinical trial registration

ClinicalTrials.gov: NCT01644890

A Real-World Retrospective Cohort Study of Combined Therapy with Bevacizumab and Paclitaxel in Japanese Patients with Metastatic Breast Cancer

OBJECTIVE

Combined therapy with bevacizumab and paclitaxel (BP regimen) as a first-line treatment has proven highly effective with good tolerance for patients with metastatic breast cancer (MBC). The objective of this study was to examine the efficacy and safety of the BP regimen for Japanese patients with MBC in real-world clinical settings.

METHODS

From June 2012 through May 2014, we recruited 94 patients at 10 medical institutions. The primary endpoint was time to treatment failure (TTF), and the secondary endpoints were overall survival (OS) and safety. Objective response was assessed according to the Response Evaluation Criteria in Solid Tumors. Adverse events (AEs) were graded according to the National Cancer Institute Common Terminology Criteria for Adverse Events version 4.0-Japan Clinical Oncology Group.

RESULTS

Nighty patients with MBC (mean 58 years, range: 34-80 years) were enrolled, and 60 (66.6%) and 52 (57.7%) had undergone prior chemotherapy as adjuvant treatment and treatment for MBC, respectively. Median TTF was 6.2 months (95% confidence interval [CI], 4.2-8.3 months), and median OS was 15.4 months (95% CI, 12.0-18.9 months). The overall response rate was 67.8% (95% CI: 57.1-77.2%). A total of 28 patients (31.1%) required a dose reduction of paclitaxel. Forty-five, 42, and 3 patients received the initial doses of 90, 80, and 60 mg/m², respectively. Among patients who received the initial doses of 90 mg/m², 13 patients (28.9%) unexpectedly required a dose reduction of ≥20 mg/m². The BP regimen was discontinued for 66 (73.3%) of the 90 patients, 52 (57.7%) of whom experienced "disease progression." Grade 3/4 hematologic AEs developed in 51 patients (56.6%), with leukopenia and neutropenia in 16 patients (17.8%) and 21 patients (23.3%), respectively. Grade 3 nonhematologic AEs developed in 8 patients (8.9%), with the most common nonhematologic AE of peripheral neuropathy in 4 patients (4.4%). No Grade 4 nonhematologic AEs developed. Peripheral neuropathy [56 patients (62.2%) ], nail discoloration [53 patients (58.9%) ], and fatigue [51 patients (56.7%) ] were the most predominant AEs-the known AEs of paclitaxel.

CONCLUSIONS

The BP regimen was active and well tolerated in the real-world clinical settings. As many as 28.9% of patients who received the initial dose of 90 mg/m² required a dose reduction of paclitaxel by 20 mg/m². Therefore, there is a need to find a therapeutic regimen that is less likely to result in dose reductions for patients with MBC who undergo a BP regimen using the initial paclitaxel dose of 90 mg/m².

Abstract P2-01-08: Enumeration of heterogeneous circulating tumor cells (CTCs) using size-based method in early, and metastatic, breast cancer patients

Background

The detection of circulating tumor cells (CTCs) in peripheral blood is an independent predictor of the efficacy of systemic therapy, and also a prognostic marker for patients with metastatic breast cancer. One of the main methods to detect CTCs is CellSearch system, which uses immune-magnetic separation followed by immunocytochemistry. A microdevice (CTChip from ClearCell system) can capture and enumerate CTCs based on distinctive physiological differences (size and deformability) between cancer cells and blood cells. CTChip thus obtains a larger CTC yield than affinity-based separation, which enriches a particular subgroup of cells expressing EpCAM. In this study, we enumerate CTCs in peripheral blood from early and metastatic breast cancer patients using a size-based method.

Patients and methods

We examined blood samples from a total of 18 early and metastatic breast cancer patients, after obtaining written informed consent. Blood samples were taken in sodium EDTA tubes after discarding the first 1ml of blood from the syringe. Two ml blood samples were applied to CTChip (ClearCell system), and CTCs were eventually trapped in the microwells of the CTChip. Trapped cells were analyzed by immunocytochemistry with monoclonal antibodies specific for leukocytes (CD45) and epithelial cells (CK8/18), along with 4',6-diamidino-2-phenylindole (DAPI) for nuclei: CK8/18-positive, DAPI-positive and CD45-negative cells more than 10 μm in diameter were defined as CTCs. Eight patients were examined using both the CTChip and CellSearch system to compare the yield of CTCs.

Results

Of 18 patients, 6 were de novo stage IV, 6 were recurrent and 6 were early stage breast cancer patients. Of primary tumors, 8 were HER2- and ER and/or PR +, 6 were HER2-and ER- and PR-, 3 were HER2+ and ER and/or PR +, and one was HER2+ and ER- and PR-. Using CTChip, detected CTCs ranged from 3 - 107 cells/2 ml in all cases: 3 - 83 for early stage, 19 - 156 for stage IV and 21 - 146 for recurrent. The number of CTCs found in recurrent patients tended to be higher than in early stage patients. Size-based method using CTChip clearly showed high sensitivity compared with the CellSearch system, which detected CTCs in only 2 cases out of 8. In analysis by immunochemistry, we found CK-negative, CD45-negative and DAPI positive cells with larger diameter (&gt;16 μm) than CK-positive CTCs in most patients, and the numbers were higher in stage IV (8.5 cells of median value) and recurrent (13 cells) patients than in early stage patients (1.5 cells). Our study suggested that CK-negative large cells might be CTCs with epithelial–mesenchymal transition (EMT).

Conclusion

This size-based technology enables us to capture CTCs regardless of EpCAM expression. Enumerated CTCs varied in size and positivity of CK8/18, suggesting the heterogeneity of CTCs. Further research, especially focusing on EMT will be crucial to understand the key mechanism of metastasis and drug resistance.

Citation Format: Tozuka K, Nagai SE, Kubo K, Komatsu K, Takai K, Inoue K, Matsumoto H, Hayashi Y, Tsuboi M, Yamada Y, Wang X, Suganuma M. Enumeration of heterogeneous circulating tumor cells (CTCs) using size-based method in early, and metastatic, breast cancer patients [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P2-01-08.

RESILIENCE: Phase III Randomized, Double-Blind Trial Comparing Sorafenib With Capecitabine Versus Placebo With Capecitabine in Locally Advanced or Metastatic HER2-Negative Breast Cancer

INTRODUCTION

Sorafenib is a multikinase inhibitor with antiangiogenic/antiproliferative activity. In this randomized, double-blind, placebo-controlled phase III trial, we assessed first- or second-line capecitabine with sorafenib or placebo in patients with locally advanced/metastatic HER2-negative breast cancer resistant to a taxane and anthracycline and with known estrogen/progesterone receptor status.

PATIENTS AND METHODS

A total of 537 patients were randomized to capecitabine 1000 mg/m² orally twice per day for days 1 to 14 every 21 days with oral sorafenib 600 mg/d or placebo. The primary end point was progression-free survival (PFS). Patients were stratified according to hormone receptor status, previous chemotherapies for metastatic breast cancer, and geographic region.

RESULTS

Treatment with sorafenib with capecitabine, compared with capecitabine with placebo, did not prolong median PFS (5.5 vs. 5.4 months; hazard ratio [HR], 0.973; 95% confidence interval [CI], 0.779-1.217; P = .811) or overall survival (OS; 18.9 vs. 20.3 months; HR, 1.195; 95% CI, 0.943-1.513; P = .140); or enhance overall response rate (ORR; 13.5% vs. 15.5%; P = .515). Any grade toxicities (sorafenib vs. placebo) included palmar-plantar erythrodysesthesia syndrome (PPES; 79.2% vs. 59.6%), diarrhea (47.3% vs. 37.8%), mucosal inflammation (15.4% vs. 6.7%), and hypertension (26.2% vs. 5.6%). Grade 3/4 toxicities included PPES (15.4% vs. 7.1%), diarrhea (4.2% vs. 6.4%), and vomiting (3.5% vs. 0.7%).

CONCLUSION

The combination of sorafenib with capecitabine did not improve PFS, OS, or ORR in patients with HER2-negative advanced breast cancer. Rates of Grade 3 toxicities were higher in the sorafenib arm.

Abstract P2-02-20: Enumeration of heterogeneous circulating tumor cells (CTCs) in metastatic breast cancer patients based on size and deformability

Background :

The detection of circulating tumor cells (CTCs) in peripheral blood is an independent predictor of the efficacy of systemic therapy and a prognostic marker for patients with metastatic breast cancer. One of the leading techniques to detect CTCs uses immune-magnetic separation followed by immunocytochemistry. A microdevice can capture and enumerate CTCs using distinctive physiological difference (size and deformability) between cancer cells and blood cells. This microdevice thus obtains a larger CTC yield than that of affinity based separation which enriches the samples from a particular subgroup of cells based on biomarker (EpCAM) used. In this study, we investigated CTCs in peripheral blood from metastatic breast cancer patients using this microdevice.

Patients and methods:

We examined blood samples of 9 patients with heavily treated locally recurrent or metastatic breast cancer. Informed consent from these patients was obtained before blood extraction. Blood samples were taken into sodium EDTA tubes after discarding the first 1ml of blood samples. Two ml whole blood were subjected to the microdevice (Clear cell system), and CTCs were trapped in the microwells: Trapped cells were analyzed by immunocytochemistry with monoclonal antibodies specific for leukocytes (CD45) and epithelial cells (CK8/18), along with 4,2-diamidino-2-phenylndole dihydrochloride (DAPI) for nuclei. CK8/18- positive, DAPI-positive and CD45-negative cells were defined as CTCs. Three patients were examined using both this microdevice and affinity-based separation with EpCAM, to compare the yield of CTCs.

Results:

Of the 9 patients: 7 had ER-positive primary tumors, and 6 had PgR-positive ones, HER2 overexpression was detected in 2 primary tumors. CTCs were detected in 8 patients. The single patient in whom CTCs were not detected suffered from local recurrence (axillary lymph node metastasis) only, with no distant metastases. We were also unable to detect CTCs using EpCAM affinity method for this patient. The number of detected CTCs in the other patients ranged from 19/2ml to 156/2ml (mean 90/2ml), and the sizes of CTCs varied from 5 to 16μm. CK8/18-negative and DAPI positive were detected in most patients, and these cells tended to be larger than CK8/18-positive cells, suggesting that epithelial–mesenchymal transition (EMT) might occur in CTCs. The total number of CTCs detected by the microdevice from 2 patients was larger than that of CTCs detected by EpCAM affinity method (107/2ml vs 1/7.5ml, and 19/2ml vs 39/7.5ml).

Conclusion:

CTCs detected by this microdevice varied in regard to the size of trapped cells and characteristics examined by immunochemistry, suggesting the heterogeneity of CTCs. Further research on this heterogeneity is vital in order to develop personalized treatment for patients with metastatic breast cancer.

Citation Format: Tozuka K, Nagai SE, Inoue K, Komatsu K, Matsumoto H, Hayashi Y, Kurozumi S, Suganuma M. Enumeration of heterogeneous circulating tumor cells (CTCs) in metastatic breast cancer patients based on size and deformability. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P2-02-20.

Abstract P4-14-17: Prognostic value of tumor-infiltrating lymphocytes in residual tumors after neoadjuvant chemotherapy concomitant with trastuzumab for HER2-positive breast cancer

Background:

Neoadjuvant chemotherapy (NAC) with taxanes, followed by fluorouracil, epirubicin, and cyclophosphamide (FEC), with concurrent trastuzumab is known to achieve a high pCR rate of more than 60% for HER2-positive breast cancer (BC) as well as good prognoses in those obtaining pCR. On the other hand, the prognostic significance of tumor-infiltrating lymphocytes (TILs) has recently been described in triple-negative BC. However, the prognostic and predictive values of TILs in HER2-positive BC remain unclear. In the present study, we examined the grades of TILs in pre-treatment cancer tissues and residual tumors after NAC with trastuzumab, and also investigated its predictive utility for pCR and prognostic power for HER2-positive BC.

Patients and Methods:

A total of 128 Japanese women with HER2-positive BC received either paclitaxel or docetaxel followed by FEC, with concomitant trastuzumab. The proportional grades of stromal (Str)-TILs in pre-treatment biopsy specimens and residual tumors after NAC with trastuzumab were determined as follows: low grade (0-10%), intermediate grade (10-40%), and high grade (40-90%), using the criteria of the International Working Group for TILs in BC. Analysis 1: The relationship between the grades of Str-TILs in pre-treatment tumors and pCR rates was investigated. Relapse-free survival (RFS) and cancer-specific survival (CSS) were analyzed for a correlation with pre-treatment Str-TILs. Analysis 2: Alterations in the grade of Str-TILs were examined in the residual tumors of non-pCR patients, and RFS and CSS were analyzed for a correlation with residual Str-TILs.

Results:

pCR was achieved in 83 out of the 128 patients (pCR rate, 64.8%) who received NAC with trastuzumab, and RFS was significantly better in the pCR group than in the non-pCR group (p = 0.0071). Analysis 1: The patient distribution of the Str-TILs grade in pre-treatment tumors was as follows: high: 24 (18.8%); intermediate: 38 (29.7%); and low: 66 (51.6%). pCR rates correlated with the Str-TILs grade in pre-treatment tumors: 83.3% in the high group, 71.1% in the intermediate group, and 54.5% in the low group (p = 0.026); however, the Str-TILs grade in pre-treatment tumors did not correlate with survival. Analysis 2: In 45 non-pCR patients, the distribution of the Str-TILs grade in residual tumors was as follows: high: 9 (20.0%); intermediate: 8 (17.8%); and low: 28 (62.2%), respectively. In non-pCR patients, the rate of a high Str-TILs grade was greater in residual tumors than in pre-treatment tumors (residual, 20.0%, pre-treatment, 8.9%). RFS was significantly better with a high grade than with a low grade of residual Str-TILs (p = 0.033).

Conclusions:

The status of TILs in pre-treatment tumors predicted responses to NAC concomitant with trastuzumab in HER2-positive BC. The grade of TILs was higher in residual tumors than in pre-treatment tumors, and, among non-pCR patients, the prognosis of patients with a high residual-TILs grade was better prognosis than that of patients with a low residual-TILs grade. We speculate that an examination of TILs in residual tumors after NAC with trastuzumab may be necessary for selecting patients with a good prognosis from non-pCR patients.

Citation Format: Kurozumi S, Inoue K, Matsumoto H, Hayashi Y, Tozuka K, Kubo K, Komatsu K, Takai K, Nagai SE, Oba H, Horiguchi J, Takeyoshi I, Kurosumi M. Prognostic value of tumor-infiltrating lymphocytes in residual tumors after neoadjuvant chemotherapy concomitant with trastuzumab for HER2-positive breast cancer. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P4-14-17.

Abstract P2-04-10: Utility of simultaneous HER2 protein and gene assessment for the evaluation of discrepancy and intratumoral heterogeneity of HER2 status and the prediction of prognosis in invasive breast cancer using the gene-protein assay (GPA)

Background:

The eligibility of patients for HER2-targeted therapies is determined by the evaluation of HER2 gene amplification and HER2 protein overexpression. The gene-protein assay (GPA, Ventana Medical Systems, Inc., USA) is a new method for simultaneous evaluation of HER2 immunohistochemistry (IHC) and dual in situ hybridization (DISH) using a single tissue section. In this study, we investigated the relationship between HER2 IHC and DISH results evaluated by GPA. In addition, we analyzed the correlation between HER2 status and prognosis of invasive breast cancer patients.

Patients and Methods:

In this study, invasive carcinoma tissues of 280 consecutive patients treated in Saitama Cancer Center in 2000-2001 (median follow-up: 130 months) were examined. Among HER2 positive initial samplings, no patients originally received adjuvant trastuzumab therapy. However, 76% of HER2 positive cases of recurrence received trastuzumab therapy. GPA was performed on a section of routinely processed primary tumor and the status of HER gene and protein were separately evaluated in whole areas of tumor sections using the following FDA criteria: DISH (negative: HER2/CEN17 &lt; 2, positive: HER2/CEN17 ≥ 2.0) and IHC (score 0 to 3+). In IHC score 2+ patients group, final HER2 positivity was decided according to DISH results using criteria of FDA criteria. Recurrence-free survival (RFS) and cancer-specific survival (CSS) stratified by IHC and DISH results were analyzed. In addition, patterns of heterogeneity were grouped according to the following 4 phenotypic and genotypic types: A) IHC 2+/DISH+; B) IHC 2+/DISH-; C) IHC 1+ & 0/DISH+; and D) IHC 1+ & 0/DISH-. The presence of heterogeneity in relation to prognosis was analyzed in the IHC 0 & 1+/DISH- group.

Results:

The HER2 IHC 3+ group (27.5%), both with or without trastuzumab therapy, had significantly worse survival than HER2 IHC 1+ & 0 group (RFS: P=0.0039; CSS: P=0.0362) and HER2 DISH+ group (27.5%) had significantly worse survival than HER2 DISH- group (RFS: P=0.0056; CSS: P=0.0497). HER2 positive group defined by FDA criteria had significantly worse RFS than HER2 negative group (P=0.0211). HER2 IHC 1+ & 0/DISH+ group had significantly worse RFS than IHC 1+ & 0/DISH- group (P=0.0208). In the HER2 IHC 1+ & 0/ DISH- group, patients with heterogeneity (33 cases) had significantly worse survival than those without heterogeneity (RFS: P=0.0176; CSS: P=0.0199).

Conclusions:

HER2 GPA technology might be useful for evaluating the discrepancy and heterogeneity of HER2 IHC and DISH results at single cell levels simultaneously and the presence of HER2 tumor cell heterogeneity might be a potent prognostic factor in HER2 negative breast cancer patients. Further clinical research must be conducted for clarification of the relationship between the presence of HER2 intratumoral heterogeneity and the effectiveness of HER2-targeted therapies.

Citation Format: Sasagu Kurozumi, Mary Padilla, Masafumi Kurosumi, Hiroshi Matsumoto, Yuji Hayashi, Katsunori Tozuka, Shigenori E Nagai, Kenichi Inoue, Hanako Oba, Jun Horiguchi, Izumi Takeyoshi, Jim Ranger-Moore, Eslie Dennis, Hiroaki Nitta. Utility of simultaneous HER2 protein and gene assessment for the evaluation of discrepancy and intratumoral heterogeneity of HER2 status and the prediction of prognosis in invasive breast cancer using the gene-protein assay (GPA) [abstract]. In: Proceedings of the Thirty-Seventh Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2014 Dec 9-13; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2015;75(9 Suppl):Abstract nr P2-04-10.

Feasibility study of TS-1 additional therapy for the triple-negative breast cancer received neoadjuvant or adjuvant chemotherapy (SBCCSG14)

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Background: Prospective randomized clinical trials have demonstrated a significant advantage from postoperative adjuvant chemotherapy for patients with breast cancer. However, triple-negative breast cancer is high rate of early recurrence. Therefore, patients who do not achieve pathological complete response (pCR) for neoadjuvant chemotherapy have worse long-term survival than patients who achieve pCR. Treatment after adjuvant chemotherapy and neoadjuvant chemotherapy is not established yet. We notice that TS-1 improve early recurrent rate of breast cancer. TS-1 proved good response for advanced breast cancer and long-term therapy is possible. We planned the study for the purpose of inspecting it about the safety, completion and efficacy of giving TS-1 after standard therapy of triple negative breast cancer for one year. Methods: The patients with stage ±/II/ III triple negative breast cancer received neoadjuvant or adjuvant chemotherapy and surgery and/or radiotherapy. Furthermore, the cases of neoadjuvant chemotherapy did not achieved pCR. After that, dose of TS-1 is 80mg/m² administered orally daily for 2 weeks followed by a 1-week rest period given as 3-week cycles. Results: 63 patients were enrolled, including 44 patients received neoadjuvant chemotherapy and 19 patients received adjuvant chemotherapy. The average age is 50 years (28-68 years). 38 cases (60.3%) brought oral administration for one year to completion. The reasons of discontinuance were 15 cases of toxicity and 10 cases of recurrence. Average relative dose intensity was 80%. The compliance of TS-1 was 70.1% (222.4 days). Overall survival of 3 years was 86.47%, progression-free survival 50.8%. The overall incidence of toxicity was 54 cases (85.7%), and grade 3 toxicity occurred in 21 cases (33.3%). Conclusions: The compliance of TS-1 was approximately equal to the compliance for gastric cancer in spite of receiving treatments of anthracycline and/or taxane. The toxicity was approximately equal to the results for metastatic breast cancer. TS-1 administered orally for one year was feasible for triple negative breast cancer received standard therapy. Clinical trial information: UMIN000001414.

Analysis of complete response by MRI following neoadjuvant chemotherapy predicts pathological tumor responses differently for molecular subtypes of breast cancer

In the present study, clinical tumor response following neoadjuvant chemotherapy (NAC) was diagnosed by magnetic resonance imaging (MRI) and clinicopathological factors, including molecular subtypes at baseline, were analyzed for correlations with pathological tumor responses. In addition, clinicopathological factors were analyzed for a correlation with the MRI capacity to predict pathological complete response (pCR). Clinical tumor response evaluated by MRI following NAC was determined as a clinical CR (cCR) or a residual tumor. cCR was confirmed if no gadolinium enhancement or an enhancement equal to or less than that of glandular tissue was observed in any phase of the MRI. Pathological tumor responses following NAC were classified into grades 0 (no change) to 3 (no residual invasive cancer) according to criteria of the Japanese Breast Cancer Society. pCR was defined as grade 3 in the present study. Of 264 cases of invasive breast cancer in 260 patients (4 synchronous bilateral breast cancer cases), 59 (22%) were diagnosed by MRI following NAC as cCR and 98 (37%) were pathologically diagnosed as pCR. In terms of predicting pCR by MRI, the sensitivity, specificity, accuracy, positive predictive value (PPV) and negative predictive value (NPV) were 44, 90, 73, 73 and 73%, respectively. Tumor size, hormone receptor status, human epidermal growth factor receptor 2 (HER2) status, molecular subtype and histological type were significantly correlated with pathological tumor responses. pCR rates increased in the following order: luminal/HER2-negative (14%), luminal/HER2-positive (32%), triple-negative (46%) and non-luminal/HER2-positive (73%) tumors. Sensitivity and specificity were the highest (60 and 100%, respectively) in triple-negative tumors. PPV decreased in the following order: triple-negative (100%), non-luminal/HER2-positive (92%), luminal/HER2-positive (46%) and luminal/HER2-negative (33%) tumors. In conclusion, MRI evaluation is useful for predicting pCR following NAC, particularly for triple-negative tumors.

Estrogen receptor (ER), Ki-67, p27Kip1, and histologic grade as predictors of pathologic complete response (pCR) in patients with HER2-positive breast cancer treated with neoadjuvant chemotherapy (NAC) using fluorouracil, epirubicin, and cyclophosphamide (FEC), taxanes, and trastuzumab

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Background: NAC with taxanes and FEC concurrently with trastuzumab is a potent regimen in patients with HER2-positive breast cancer (BC). Several studies revealed high pCR rates in BC patients treated with this regimen; however, predictive factors and a prognostic effect of pCR have been still unclear. In this study, we analyzed several factors including p27Kip1 (cyclin-dependent kinase inhibitor acting as tumor suppressor) for correlation with pCR. We also evaluated differences in recurrence-free survival (RFS) or overall survival (OS) between patients with pCR and non-pCR, and with positive and negative nodes after NAC. Methods: Our study included 129 Japanese women with invasive, HER2-positive BC who received 12 cycles of paclitaxel or 4 cycles of docetaxel followed by 4 cycles of FEC-75 with concomitant trastuzumab for 24 weeks. We analyzed the correlation of pCR (no invasive lesions in the breast) and nodal status after NAC with RFS and OS, and analyzed the baseline expressions of ER, Ki-67, and p27Kip1, and histological grade for correlation with pCR. Positive or high expression was defined by nuclear labeling index: ER ≥10%, p27Kip1 ≥75%, Ki-67 ≥30%. Results: In 129 patients, pCR was found in 85 (66%). Patients with pCR after NAC had significantly better RFS than those without pCR (median follow-up: 41 months). Furthermore, patients with pathologically negative nodes after NAC had significantly better OS than those with pathologically positive nodes. Negative ER (79% vs. 40%), high Ki-67 (72% vs. 47%), low p27Kip1 (71% vs. 50%), and histological grade 3 (70% vs. 39%) were significant predictors of pCR. Conclusions: In patients with HER2-positive BC, this regimen was effective achieving the high pCR rate. pCR and pathologically negative nodes after NAC were predictive of RFS and OS, respectively. The expressions of ER, Ki-67, and p27Kip1, and histological grade at baseline were predictive of pCR. p27Kip1, a new predictor of pCR after NAC needs to be further analyzed.