Uracil-tegafur and tamoxifen vs cyclophosphamide, methotrexate, fluorouracil, and tamoxifen in post-operative adjuvant therapy for stage I, II, or IIIA lymph node-positive breast cancer: a comparative study

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

PURPOSE

The Phase III POTENT trial demonstrated the efficacy of adding S-1 to adjuvant endocrine therapy for estrogen receptor-positive, HER2-negative early breast cancer. We investigated the efficacy of S-1 across different recurrence risk subgroups.

METHODS

This was a post-hoc exploratory analysis of the POTENT trial. Patients in the endocrine-therapy-only arm were divided into three groups based on composite risk values calculated from multiple prognostic factors. The effects of S-1 were estimated using the Cox model in each risk group. The treatment effects of S-1 in patients meeting the eligibility criteria of the monarchE trial were also estimated.

RESULTS

A total of 1,897 patients were divided into three groups: group 1 (≤ lower quartile of the composite values) (N = 677), group 2 (interquartile range) (N = 767), and group 3 (> upper quartile) (N = 453). The addition of S-1 to endocrine therapy resulted in 49% (HR: 0.51, 95% CI: 0.33-0.78) and 29% (HR: 0.71, 95% CI 0.49-1.02) reductions in invasive disease-free survival (iDFS) events in groups 2 and 3, respectively. We could not identify any benefit from the addition of S-1 in group 1. The addition of S-1 showed an improvement in iDFS in patients with one to three positive nodes meeting the monarchE cohort 1 criteria (N = 290) (HR: 0.47, 95% CI: 0.29-0.74).

CONCLUSIONS

The benefit of adding adjuvant S-1 was particularly marked in group 2. Further investigations are warranted to explore the optimal usage of adjuvant S-1.

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

BACKGROUND

Oral fluoropyrimidines, such as S-1, have been shown to have a role in controlling disease progression in metastatic breast cancer. We examined adjuvant treatment with S-1 in patients with oestrogen receptor (ER)-positive and HER2-negative primary breast cancer.

METHODS

We did a multicentre, open-label, randomised, controlled, phase 3 trial in 139 sites (137 hospitals and two clinics). Eligible patients were women aged 20-75 years with histologically diagnosed stage I to IIIB invasive breast cancer (intermediate to high risk of recurrence). Patients were temporarily registered at participating institutions and biopsy or surgical samples were collected and sent for central pathological assessment. Patients received 5 years of standard adjuvant endocrine therapy (selective oestrogen receptor modulators with or without ovarian suppression and aromatase inhibitors) with or without 1 year of S-1. Oral S-1 80-120 mg/day was administered twice a day for 14 days with 7 days off. Randomisation (1:1) using the minimisation method was done with six stratification factors (age, axillary lymph node metastasis at surgery or sentinel lymph node biopsy, preoperative or postoperative (neoadjuvant or adjuvant) chemotherapy, preoperative endocrine therapy, proportion of ER-positive cells, and study site). The primary endpoint was invasive disease-free survival, in the full analysis set (all randomly assigned patients, excluding those with significant protocol deviations). The safety analysis set consisted of all patients who received at least one dose of study treatment. Here, we report the results from the interim analysis at the data cutoff date Jan 31, 2019. This trial is registered with Japan Registry of Clinical Trials, jRCTs051180057, and the University hospital Medical Information Network, UMIN000003969.

FINDINGS

Between Feb 1, 2012, and Feb 1, 2016, 1930 patients were enrolled in the full analysis set, 957 (50%) received endocrine therapy plus S-1 and 973 (50%) received endocrine therapy alone. Median follow-up was 52·2 months (IQR 42·1-58·9). 155 (16%) patients in the endocrine therapy alone group and in 101 (11%) patients in the endocrine therapy plus S-1 group had invasive disease-free survival events (hazard ratio 0·63, 95% CI 0·49-0·81, p=0·0003). As the primary endpoint was met at interim analysis, the trial was terminated early. The most common grade 3 or worse adverse events were decreased neutrophil count (72 [8%] of 954 patients in the endocrine therapy plus S-1 group vs seven [1%] of 970 patients in the endocrine therapy alone group), diarrhoea (18 [2%] vs none), decreased white blood cells (15 [2%] vs two [<1%]), and fatigue (six [<1%] vs none). Serious adverse events were reported in nine (1%) of 970 patients in the endocrine therapy alone group and 25 (3%) of 954 patients in the endocrine therapy plus S-1 group. There was one (<1%) possible treatment-related death in the endocrine therapy plus S-1 group due to suspected pulmonary artery thrombosis.

INTERPRETATION

These data suggest that this combination of S-1 with endocrine therapy could be a potential treatment option for this intermediate and high-risk group of patients with ER-positive, HER2-negative primary breast cancer.

FUNDING

Public Health Research Foundation (Japan), Taiho Pharmaceutical.

Relationships between pathological factors and long-term outcomes in patients enrolled in two prospective randomized controlled trials comparing the efficacy of oral tegafur-uracil with CMF (N·SAS-BC 01 trial and CUBC trial)

PURPOSE

To evaluate the efficacies of cyclophosphamide, methotrexate, and fluorouracil (CMF) and tegafur-uracil (UFT) as adjuvant therapy in patients with resected stage I-IIIA breast cancer by immunohistochemistry (IHC)-based subtype and to determine the relationships between clinicopathological factors and long-term outcomes.

METHODS

A pooled analysis of the randomized controlled N·SAS-BC 01 and CUBC studies was conducted. Expression of hormone receptors (HRs; estrogen and progesterone receptors), human epidermal growth factor receptor 2 (HER2), and Ki67were assessed by IHC. Tumor-infiltrating lymphocytes (TILs) and nuclear/histological grades were determined by hematoxylin and eosin staining. Relapse-free survival (RFS) and overall survival (OS) were estimated by Kaplan-Meier analysis and hazard ratios were determined by Cox model adjusted for baseline tumor size and nodal status.

RESULTS

A total of 689 patients (342 CMF and 347 UFT) were included in the analyses with a median follow-up of 11.1 years. There was no significant difference in RFS or OS between the two cohorts (RFS: 0.96 [95% confidence interval: 0.71-1.30], log-rank test p = 0.80; OS: 0.93 [0.64-1.35], p = 0.70). There was no difference in RFS or OS between the two cohorts for HR+/HER2- and HR+/HER2+ subtypes. RFS was significantly longer in patients treated with UFT compared with CMF in patients with HR-/HER2+ subtype (0.30 [0.10-0.88], p = 0.03). A high TILs level was associated with a better OS compared with low TILs level (p = 0.02).

CONCLUSIONS

This long-term follow-up study showed that RFS and OS were similar in patients with luminal-type breast cancer treated with CMF and UFT.

Estrogen Down-regulator Fulvestrant Potentiates Antitumor Activity of Fluoropyrimidine in Estrogen-responsive MCF-7 Human Breast Cancer Cells

BACKGROUND

Endocrine therapy is clinically administered in hormone-responsive breast cancer. Combinations of fluoropyrimidine S-1 and an aromatase inhibitor or anti-estrogen are considered beneficial in Japan. Herein we assessed new combinations of S-1 and fulvestrant.

PATIENTS AND METHODS

Cytotoxicity of fulvestrant and 5-fluorouracil (5-FU) was assessed in hormone-responsive (MCF-7) and non-responsive (MDA-MB-231) breast cancer cell cultures. Fulvestrant and S-1 were evaluated for antitumor activity in mice and their effects on estrogen receptor (ER)-α and progesterone receptor (PgR) levels in MCF-7 xenografts using immunohistochemical methods.

RESULTS

Fulvestrant inhibited growth of MCF-7, but not of MDA-MB-231 xenografts. Combinations of 5-FU and fulvestrant were superior to monotherapy in vitro. In vivo antitumor activity of S-1/fulvestrant combination therapy was significantly (p<0.05) enhanced compared to that of both monotherapies. Fulvestrant partially down-regulated expression of ERα and PgR, but in combination with S-1, it almost completely blocked their expression.

CONCLUSION

Chemo-endocrine combination therapy using S-1 and fulvestrant is beneficial in estrogen-responsive breast cancer.

The impact of age on the risk of ipsilateral breast tumor recurrence after breast-conserving therapy in breast cancer patients with a > 5 mm margin treated without boost irradiation

BACKGROUND

The boost irradiation to the tumor bed following whole-breast irradiation (WBI) reduced the risk of ipsilateral breast tumor recurrence (IBTR). However, in Japan, almost all patients with a margin ≤5 mm receive boost irradiation to the tumor bed, but the decision to perform boost irradiation for those with a margin > 5 mm is dependent on the institution. Thus, institutional guidelines on utilizing boost irradiation for patients aged ≤40 or ≤ 50 years vary. We investigated the IBTR rate to assess the appropriate age for boost irradiation to the tumor bed with a margin > 5 mm.

METHODS

From January 1993 to December 2010, 419 patients with early-stage breast cancer and negative margins (> 5 mm) after breast-conserving surgery received WBI without boost irradiation. The Gray test was used to compare the cumulative incidence of IBTR among patients aged ≤40, 41-50, and ≥ 51 years. Hazard ratios were estimated using the Fine and Gray models. Furthermore, as a subgroup analysis, we investigated whether IBTR depended on the use of systemic therapy, such as anthracycline or taxane regimens.

RESULTS

The median follow-up time was 9.3 years. In multivariate analysis, only age predicted IBTR (p = 0.047). The 10-year IBTR rate was 15.7% in patients aged ≤40, 3.8% in those aged 41-50, and 2.0% in patients aged ≥51 years. The difference between patients aged ≤40 and 41-50 years was statistically significant (p = 0.045), whereas the difference between patients aged 41-50 and ≥ 51 years was not significant (p = 0.21).

CONCLUSIONS

In our institutional surgical setting, when boost irradiation is performed only for patients with a margin ≤5 mm, the IBTR rate after WBI without boost irradiation was significantly higher in patients aged ≤40 years, suggesting that boost irradiation should be used for patients in this age group.

Multidisciplinary treatment for locally advanced breast cancer with internal mammary lymph node metastasis in an elderly patient

Internal mammary lymph node (IMLN) metastasis is one of the important prognostic indicators in breast cancer. However, the management for IMLN metastasis is not established. The dissection for IMLN metastasis is not recommended in the National Comprehensive Cancer Network guidelines version3. 2015. Furthermore, radiotherapy including IMLN region and biopsy have attendant risks and hence should be performed with caution. Here, we describe our experience of multidisciplinary treatment for locally advanced breast cancer with IMLN metastasis in an elderly patient. Core-needle biopsy of the breast tumor histologically diagnosed the tumor as estrogen receptor positive, progesterone receptor positive, human epidermal growth factor receptor-2 negative, and high Ki-67 labeling index. IMLN swelling was detected by ultrasonography and breast cancer metastasis was diagnosed by fine-needle aspiration cytology. The patient underwent mastectomy and axillary lymph node dissection, followed by postmastectomy radiation therapy. Systemic therapy using tegafur plus uracil (UFT®; Taiho Pharmaceutical Co., Ltd, Tokyo, Japan) and letrozole was beneficial treatment for disease control.

Randomized phase II study of anastrozole plus tegafur-uracil as neoadjuvant therapy for ER-positive breast cancer in postmenopausal Japanese women (Neo-ACET BC)

Purpose

This phase II study evaluated the efficacy and safety of anastrozole concurrent with tegafur/uracil (UFT) as neoadjuvant therapy for ER-positive postmenopausal breast cancer.

Methods

Postmenopausal Japanese women with ER-positive, HER2-negative, T2,N0-1,M0 breast cancer seen at tertiary hospitals were eligible for this open-label, randomized, multicenter study. Patients were randomized 1:1 by minimization to orally receive either anastrozole (1 mg once daily) plus UFT (tegafur/uracil combination in 1:4 molar ratio; 270 mg/m²/day in two divided doses) or anastrozole (as above) alone for 24 weeks. Tumor response was assessed by investigator and central review as per RECIST v1.1. The primary endpoint was the proportion of patients with best overall response of CR or PR [clinical response rate (RR)] determined by central radiologic review.

Results

The study was prematurely terminated due to Grade ≥ 3 liver dysfunction reported in 3 patients receiving anastrozole/UFT. Of 57 patients randomized before termination (29 anastrozole/UFT, 28 anastrozole), all were analyzed for safety and 56 (28 each group) for tumor response. Compared with anastrozole alone, anastrozole/UFT did not achieve significantly higher RR [39.3% (90% CI 23.8–56.5%) vs 14.3% (90% CI 5.0–29.8%); p = 0.0683, Fisher’s exact test], but produced significantly greater tumor shrinkage (mean tumor reduction rate 31.0 vs. 14.2%; p = 0.0181, unpaired t-test). Grade ≥ 3 adverse events were more common with anastrozole/UFT than with anastrozole (17.2 vs. 0%).

Conclusion

Although the study was terminated owing to the altered liver function, it showed that there was a trend to greater shrinkage of tumor in the combination group for ER-positive, HER2-negative postmenopausal breast cancer.

Metronomics in the neoadjuvant and adjuvant treatment of breast cancer

The concept of metronomic chemotherapy (MC) has evolved from a descriptive preclinical phenomenon encompassing inhibition of angiogenesis to a clinically validated treatment concept involving multiple potential mechanisms of action. Clinicians are progressively more incline to consider MC as a component of mainstream medical oncology practice in advanced breast cancer. However, more recently MC has been tested even in the adjuvant/neoadjuvant setting, taking the opportunity to obtain tumor specimens and blood samples, in order to identify tumor-specific or patient-specific biomarkers for personalizing treatments. In addition, the antiangiogenic and pro-immune nature of metronomic chemotherapy made triple negative breast cancer (TNBC) a good candidate for exploring low-dose maintenance treatment in the adjuvant setting or in combination with immunomodulatory drugs. The potential development of MC in breast cancer pass through the research to identify biomarkers and individual tumor characteristics that can better address the use of this treatment strategy in the future. Finally, the subjective attitude of patients represents one of the major factors that influence the choice and acceptance of a therapeutic program. Personal preference and considerations about quality of life should guide the treatment choice eventually prioritizing the use of MC. Nevertheless, more robust data from randomized phase III trials are needed in the future, in order to make clinicians more confident in using metronomic strategies.

Breast cancer follow-up strategies in randomized phase III adjuvant clinical trials: a systematic review

The effectiveness of different breast cancer follow-up procedures to decrease breast cancer mortality are still an object of debate, even if intensive follow-up by imaging modalities is not recommended by international guidelines since 1997. We conducted a systematic review of surveillance procedures utilized, in the last ten years, in phase III randomized trials (RCTs) of adjuvant treatments in early stage breast cancer with disease free survival as primary endpoint of the study, in order to verify if a similar variance exists in the scientific world. Follow-up modalities were reported in 66 RCTs, and among them, minimal and intensive approaches were equally represented, each being followed by 33 (50%) trials. The minimal surveillance regimen is preferred by international and North American RCTs (P = 0.001) and by trials involving more than one country (P = 0.004), with no relationship with the number of participating centers (P = 0.173), with pharmaceutical industry sponsorship (P = 0.80) and with trials enrolling > 1000 patients (P = 0.14). At multivariate regression analysis, only geographic location of the trial was predictive for a distinct follow-up methodology (P = 0.008): Western European (P = 0.004) and East Asian studies (P = 0.010) use intensive follow-up procedures with a significantly higher frequency than international RCTs, while no differences have been detected between North American and international RCTs. Stratifying the studies according to the date of beginning of patients enrollment, before or after 1998, in more recent RCTs the minimal approach is more frequently followed by international and North American RCTs (P = 0.01), by trials involving more than one country (P = 0.01) and with more than 50 participating centers (P = 0.02). It would be highly desirable that in the near future breast cancer follow-up procedures will be homogeneous in RCTs and everyday clinical settings.

Evidence produced in Japan: tegafur-based preparations for postoperative chemotherapy in breast cancer

Oral fluoropyrimidine anticancer agents (oral 5-fluorouracil [5-FU]) able to be used as chemotherapy for breast cancer include tegafur–uracil (UFT), tegafur–gimeracil–oteracil potassium (S-1), doxifluridine, and capecitabine. Since the 1980s, UFT has been most widely used for postoperative chemotherapy in breast cancer. UFT is an oral preparation that was designed to achieve and maintain high concentrations of 5-FU in plasma by combining tegafur, a prodrug of 5-FU, with uracil. UFT is characterized by mild adverse events, allowing long-term treatment. The prolonged maintenance of high plasma 5-FU concentrations has been suggested to inhibit micrometastases after surgery. Recently, large clinical trials conducted in Japan have shown that UFT-based postoperative chemotherapy is therapeutically useful in patients with node-negative (n0), high-risk breast cancer. We review the results of clinical trials of postoperative chemotherapy with UFT in Japan and discuss its roles and future prospects.

Preferences for oral versus intravenous adjuvant chemotherapy among early breast cancer patients

PURPOSE

The purpose of this study was to evaluate preferences for oral versus intravenous adjuvant chemotherapy among early breast cancer patients (UMIN-CTR number UMIN000004696).

PATIENTS AND METHODS

Eighty-two postmenopausal women with estrogen receptor-positive, human epidermal growth-factor receptor 2-negative breast cancer who had completed adjuvant chemotherapy were asked about their preferred route of administration of chemotherapy and the reason. Women also answered questions about their physical and psychological status and quality of life during chemotherapy.

RESULTS

Patients who had received oral chemotherapy preferred it more frequently than those who had received intravenous chemotherapy (100% versus 37%, respectively, chi-square =15.5; P<0.001). Patients who preferred the same route of administration of chemotherapy as they had previously received showed a significantly better psychological status during chemotherapy compared with those who preferred a different route.

CONCLUSION

Our study showed that preferences for oral and intravenous chemotherapy strongly depended on the actual prior administration of chemotherapy and patients' own experiences during chemotherapy.

Does surgery for breast cancer induce angiogenesis and thus promote metastasis?

At the time of surgery for breast cancer, cancer cells released from the primary tumor have most likely entered blood or lymphatic vessels, leading to the development of micrometastases. Cancer cells directly produce angiogenesis stimulators, provoke the release of stimulators bound to the surrounding extracellular matrix and induce macrophages to secrete angiogenesis stimulators, thereby promoting angiogenesis. Metastasis dormancy is characterized by a balance between cell proliferation and apoptosis and is thought to be controlled by increased apoptosis, indirectly induced by angiogenesis inhibitors. Many patients with solid tumors already have micrometastases at the time of detection and surgical removal of their primary tumors. Primary tumor resection is believed to stimulate angiogenesis, initiating the proliferation of latent micrometastases. Latent micrometastases have already acquired angiogenic potential. The provision of additional therapy to inhibit angiogenesis after surgery is therefore considered a rational approach. The effectiveness of dormancy therapy should be evaluated in the prospective clinical trials of chemotherapy with drugs such as cyclophosphamide and UFT, which have been reported to inhibit angiogenesis as demonstrated by the numbers of circulating endothelial cells and circulating endothelial progenitors in peripheral blood before and after surgery in women with primary breast cancer.

Current status of therapy for breast cancer worldwide and in Japan

The results of clinical trials conducted in Europe and North America have been incorporated into treatment strategies for breast cancer in Japan. Despite the use of similar treatment regimens, why has mortality from breast cancer been increasing in Japan? Procedures for surgical treatment and sentinel lymph node biopsy in breast cancer do not differ between Japan and Western countries, but the strategies for radiotherapy differ slightly. Hormonal therapy is now selected on the basis of scientific evidence, and similar regimens are used in Japan and Western countries. As for postoperative adjuvant chemotherapy, an anthracycline plus cyclophosphamide and taxane-based regimens are standard treatments in Japan and Western countries. In 2009, however, the results of two large clinical studies designed to determine whether intravenous or oral treatment was superior for postoperative adjuvant chemotherapy were reported in Japan. Both studies showed that relapse-free survival and overall survival (OS) at 5 years after surgery were similar for a combination of cyclophosphamide, methotrexate, and 5-fluorouracil and for tegafur/uracil. Many chemotherapeutic agents that are used to treat recurrent or metastatic breast cancer have not yet been approved in Japan. As for molecular targeted therapy, some agents that target the human epidermal growth factor receptor family have been approved in Japan, whereas angiogenesis inhibitors have not. The results of many clinical trials have been incorporated into clinical practice in Japan, therefore, the outcomes of breast cancer therapy have surpassed those in other countries. Many pivotal clinical trials have been conducted outside Japan. Treatment regimens that have been developed on the basis of these studies might be suitable for the management of breast cancer in Western women, but not for Japanese women because of differences in genetic factors, physique, body mass index, pharmacokinetics, and drug metabolism. Such regimens should be modified on the basis of the characteristics of breast cancer in Japan to develop treatment that is optimally suited for Japanese women. In particular, local studies of pharmacokinetics, pharmacodynamics, and optimal dose levels and treatment intervals should be carefully performed. The establishment of treatment regimens optimally suited for Japanese patients with breast cancer could put the brakes on the trend towards increasing mortality from breast cancer in Japan.

Oral fluoropyrimidine may augment the efficacy of aromatase inhibitor via the down-regulation of estrogen receptor in estrogen-responsive breast cancer xenografts

The present preclinical study was designed to evaluate a new combination therapy comprised of the aromatase inhibitor anastrozole (ANA) and the oral fluoropyrimidines, UFT and S-1 against the estrogen receptor (ER)-positive human breast cancer cell line MCF-7/Arom 14, which was stably transfected with the cDNA of human aromatase. MCF-7/Arom 14 cells showed a high aromatase activity and notably were able to grow in the presence of testosterone and estradiol (E(2)) in vitro. ANA and 5-fluorouracil (5-FU) inhibited cell growth at concentrations of 0.005-10 and 0.2-5 μM, respectively, and the combination of both drugs additively inhibited cell growth. The growth of MCF-7/Arom 14 tumors was significantly inhibited by ANA and S-1 or UFT in vivo. The combination of ANA with S-1 or UFT administered using a 21-day consecutive, metronomic-like regimen significantly enhanced the antitumor efficacy, suppressing tumor growth for 2-4 times longer than monotherapy. To investigate the mechanisms by which S-1 enhances the antitumor activity of ANA, the protein and mRNA expression levels of ER-α in tumor tissue after treatment with S-1, ANA, and the typical chemotherapeutic agents doxorubicin (ADM) or paclitaxel (TXL) were analyzed. The protein and mRNA expression levels of ER-α in the tumor tissue were markedly decreased after treatment with S-1 or S-1 + ANA, but not after treatment with either ADM or TXL. The reduced ER-α level after S-1 treatment might contribute to the increased antitumor activity of ANA by reducing ER-α-induced growth signaling in addition to the decrease in estrogen production induced by ANA. Based on these results, the combination of ANA and S-1 might yield a greater benefit than other chemotherapeutic agents in postmenopausal women with ER-positive breast cancer.

Therapeutic usefulness of postoperative adjuvant chemotherapy with Tegafur-Uracil (UFT) in patients with breast cancer: focus on the results of clinical studies in Japan

In Japan, the history of postoperative chemotherapy for breast cancer started with 5-fluorouracil (5-FU), launched in the 1980s. Currently, oral fluoropyrimidine-based regimens indicated for the treatment of breast cancer in Japan include tegafur plus uracil (UFT); tegafur, gimeracil, and oteracil (TS-1); doxifluridine; and capecitabine. In particular, UFT represents an important option for long-term treatment because of minimal adverse events and the potential for long-term maintenance of effective plasma concentrations of 5-FU to inhibit micrometastasis after surgery. Therefore, various clinical studies of postoperative adjuvant chemotherapy with UFT have been conducted in patients with completely resected tumors. Recent studies have shown that UFT prolongs survival after tumor resection in patients with gastric cancer, colorectal cancer, and lung cancer. In patients with breast cancer, large clinical trials of UFT-based postoperative chemotherapy conducted in Japan have shown that UFT is useful for the treatment of intermediate-risk patients with no lymph node metastasis. This paper reviews the results of clinical studies of UFT conducted in Japan to assess the therapeutic usefulness of this oral 5-FU. The types of patients most likely to benefit from UFT are discussed on the basis of currently available evidence and a global consensus of treatment recommendations. The optimal timing of endocrine therapy and strategies for postoperative adjuvant chemotherapy with UFT in patients with breast cancer are also discussed.