ESGO-ESMO-ESP consensus conference recommendations on ovarian cancer: pathology and molecular biology and early, advanced and recurrent disease.

The European Society of Gynaecological Oncology, the European Society for Medical Oncology (ESMO) and the European Society of Pathology held a consensus conference (CC) on ovarian cancer on 15-16 June 2022 in Valencia, Spain. The CC panel included 44 experts in the management of ovarian cancer and pathology, an ESMO scientific advisor and a methodologist. The aim was to discuss new or contentious topics and develop recommendations to improve and harmonise the management of patients with ovarian cancer. Eighteen questions were identified for discussion under four main topics: (i) pathology and molecular biology, (ii) early-stage disease and pelvic mass in pregnancy, (iii) advanced stage (including older/frail patients) and (iv) recurrent disease. The panel was divided into four working groups (WGs) to each address questions relating to one of the four topics outlined above, based on their expertise. Relevant scientific literature was reviewed in advance. Recommendations were developed by the WGs and then presented to the entire panel for further discussion and amendment before voting. This manuscript focuses on the recommendation statements that reached a consensus, their voting results and a summary of evidence supporting each recommendation.

Olaparib plus bevacizumab first-line maintenance in ovarian cancer: final overall survival results from the PAOLA-1/ENGOT-ov25 trial.

BACKGROUND: In the PAOLA-1/ENGOT-ov25 primary analysis, maintenance olaparib plus bevacizumab demonstrated a significant progression-free survival (PFS) benefit in newly diagnosed advanced ovarian cancer patients in clinical response after first-line platinum-based chemotherapy plus bevacizumab, irrespective of surgical status. Prespecified, exploratory analyses by molecular biomarker status showed substantial benefit in patients with a BRCA1/BRCA2 mutation (BRCAm) or homologous recombination deficiency (HRD; BRCAm and/or genomic instability). We report the prespecified final overall survival (OS) analysis, including analyses by HRD status. PATIENTS AND METHODS: Patients were randomized 2 : 1 to olaparib (300 mg twice daily; up to 24 months) plus bevacizumab (15 mg/kg every 3 weeks; 15 months total) or placebo plus bevacizumab. Analysis of OS, a key secondary endpoint in hierarchical testing, was planned for ∼60% maturity or 3 years after the primary analysis. RESULTS: After median follow-up of 61.7 and 61.9 months in the olaparib and placebo arms, respectively, median OS was 56.5 versus 51.6 months in the intention-to-treat population [hazard ratio (HR) 0.92, 95% confidence interval (CI) 0.76-1.12; P = 0.4118]. Subsequent poly(ADP-ribose) polymerase inhibitor therapy was received by 105 (19.6%) olaparib patients versus 123 (45.7%) placebo patients. In the HRD-positive population, OS was longer with olaparib plus bevacizumab (HR 0.62, 95% CI 0.45-0.85; 5-year OS rate, 65.5% versus 48.4%); at 5 years, updated PFS also showed a higher proportion of olaparib plus bevacizumab patients without relapse (HR 0.41, 95% CI 0.32-0.54; 5-year PFS rate, 46.1% versus 19.2%). Myelodysplastic syndrome, acute myeloid leukemia, aplastic anemia, and new primary malignancy incidence remained low and balanced between arms. CONCLUSIONS: Olaparib plus bevacizumab provided clinically meaningful OS improvement for first-line patients with HRD-positive ovarian cancer. These prespecified exploratory analyses demonstrated improvement despite a high proportion of patients in the placebo arm receiving poly(ADP-ribose) polymerase inhibitors after progression, confirming the combination as one of the standards of care in this setting with the potential to enhance cure.

Continuous versus intermittent extended adjuvant letrozole for breast cancer: final results of randomized phase III SOLE (Study of Letrozole Extension) and SOLE Estrogen Substudy.

BACKGROUND: Late recurrences in postmenopausal women with hormone receptor-positive breast cancers remain an important challenge. Avoidance or delayed development of resistance represents the main objective in extended endocrine therapy (ET). In animal models, resistance was reversed with restoration of circulating estrogen levels during interruption of letrozole treatment. This phase III, randomized, open-label Study of Letrozole Extension (SOLE) studied the effect of extended intermittent letrozole treatment in comparison with continuous letrozole. In parallel, the SOLE estrogen substudy (SOLE-EST) analyzed the levels of estrogen during the interruption of treatment. PATIENTS AND METHODS: SOLE enrolled 4884 postmenopausal women with hormone receptor-positive, lymph node-positive, operable breast cancer between December 2007 and October 2012 and among them, 104 patients were enrolled in SOLE-EST. They must have undergone local treatment and have completed 4-6 years of adjuvant ET. Patients were randomized between continuous letrozole (2.5 mg/day orally for 5 years) and intermittent letrozole treatment (2.5 mg/day for 9 months followed by a 3-month interruption in years 1-4 and then 2.5 mg/day during all of year 5). RESULTS: Intention-to-treat population included 4851 women in SOLE (n = 2425 in the intermittent and n = 2426 in the continuous letrozole groups) and 103 women in SOLE-EST (n = 78 in the intermittent and n = 25 in the continuous letrozole groups). After a median follow-up of 84 months, 7-year disease-free survival (DFS) was 81.4% in the intermittent group and 81.5% in the continuous group (hazard ratio: 1.03, 95% confidence interval: 0.91-1.17). Reported adverse events were similar in both groups. Circulating estrogen recovery was demonstrated within 6 weeks after the stop of letrozole treatment. CONCLUSIONS: Extended adjuvant ET by intermittent administration of letrozole did not improve DFS compared with continuous use, despite the recovery of circulating estrogen levels. The similar DFS coupled with previously reported quality-of-life advantages suggest intermittent extended treatment is a valid option for patients who require or prefer a treatment interruption.

Network-analysis-guided synthesis of weisaconitine D and liljestrandinine.

General strategies for the chemical synthesis of organic compounds, especially of architecturally complex natural products, are not easily identified. Here we present a method to establish a strategy for such syntheses, which uses network analysis. This approach has led to the identification of a versatile synthetic intermediate that facilitated syntheses of the diterpenoid alkaloids weisaconitine D and liljestrandinine, and the core of gomandonine. We also developed a web-based graphing program that allows network analysis to be easily performed on molecules with complex frameworks. The diterpenoid alkaloids comprise some of the most architecturally complex and functional-group-dense secondary metabolites isolated. Consequently, they present a substantial challenge for chemical synthesis. The synthesis approach described here is a notable departure from other single-target-focused strategies adopted for the syntheses of related structures. Specifically, it affords not only the targeted natural products, but also intermediates and derivatives in the three families of diterpenoid alkaloids (C-18, C-19 and C-20), and so provides a unified synthetic strategy for these natural products. This work validates the utility of network analysis as a starting point for identifying strategies for the syntheses of architecturally complex secondary metabolites.

Correction to: The use of PIPAC (pressurized intraperitoneal aerosol chemotherapy) in gynecological oncology: a statement by the Arbeitsgemeinschaft Gynaekologische Onkologie (AGO) Kommission Ovar, AGO Study Group, North-Eastern German Society of Gynaecologic Oncology (NOGGO), AGO Austria and AGO Switzerland.

The title of the article has been published incorrectly. The correct title is given below.

The use of PIPAC (pressurized intraperitoneal aerosol chemotherapy) in gynecological oncology: a statement by the "Arbeitsgemeinschaft Gynaekologische Onkologie Studiengruppe Ovarialkarzinom (AGO-OVAR)", the Swiss and Austrian AGO, and the North-Eastern German Society of Gynaecologic Oncology.

BACKGROUND: Ovarian, tubal, and peritoneal carcinomas primarily affect the peritoneal cavity, and they are typically diagnosed at an advanced tumor stage (Foley, Rauh-Hain, del Carmen in Oncology (Williston Park) 27:288-294, 2013). In the course of primary surgery, postoperative tumor residuals are, apart from the tumor stage, the strongest independent factors of prognosis (du Bois, Reuss, Pujade-Lauraine, Harter, Ray-Coquard, Pfisterer in Cancer 115:1234-1244, 2009). Due to improved surgical techniques, including the use of multi-visceral procedures, macroscopic tumor clearance can be achieved in oncological centers, in most cases (Harter, Muallem, Buhrmann et al in Gynecol Oncol 121:615-619, 2011). However, to date, it has not been shown that peritoneal carcinomatosis is, per se, an independent factor of prognosis or that it excludes the achievement of tumor clearance. Several studies have shown that a preceding drug therapy in peritoneal carcinomatosis could positively influence the overall prognosis (Trimbos, Trimbos, Vergote et al in J Natl Cancer Inst 95:105-112, 2003). In relapses of ovarian carcinoma, studies have shown that peritoneal carcinomatosis is a negative predictor of complete tumor resection; however, when it is possible to resect the tumor completely, peritoneal carcinomatosis does not play a role in the prognosis (Harter, Hahmann, Lueck et al in Ann Surg Oncol 16:1324-1330, 2009). RESULTS: PIPAC is a highly experimental method for treating patients with ovarian, tubal, and peritoneal cancer. To date, only three studies have investigated a total of 184 patients with peritoneal carcinomatosis (Grass, Vuagniaux, Teixeira-Farinha, Lehmann, Demartines, Hubner in Br J Surg 104:669-678, 2017). Only some of those studies were phase I/II studies that included PIPAC for patients with different indications and different cancer entities. It is important to keep in mind that the PIPAC approach is associated with relatively high toxicity. To date, no systematic dose-finding studies have been reported. Moreover, no studies have reported improvements in progression-free or overall survival associated with PIPAC therapy. CONCLUSIONS: Randomized phase III studies are required to evaluate the effect of this therapy compared to other standard treatments (sequential or simultaneous applications with systemic chemotherapy). In cases of ovarian, tubal, and peritoneal cancer, PIPAC should not be performed outside the framework of prospective, controlled studies.

Front-line therapy of advanced epithelial ovarian cancer: standard treatment.

Paclitaxel and carboplatin combination chemotherapy has remained the standard of care in the front-line therapy of advanced epithelial ovarian cancer during the last decade. Maintenance chemotherapy has not been proven to impact on overall survival. Acceptable alternatives include weekly paclitaxel plus 3-weekly carboplatin, the addition of bevacizumab to 3-weekly carboplatin and paclitaxel, and intraperitoneal chemotherapy. In particular, anti-angiogenic therapy has been identified as the most promising targeted therapy, and the addition of bevacizumab to first-line chemotherapy followed by a maintenance period of bevacizumab in monotherapy has shown to prolong progression-free survival. This was considered the proof of concept of the value of anti-angiogenic therapy in the front-line of ovarian cancer, and the results of two additional clinical trials with anti-angiogenic tyrosine kinase inhibitors have shown results in the same direction.

Fifth Ovarian Cancer Consensus Conference: individualized therapy and patient factors.

This manuscript reports the consensus statements regarding the design and conduct of clinical trials in patients with newly diagnosed and recurrent epithelial ovarian cancer (EOC), following deliberation at the Fifth Ovarian Cancer Consensus Conference (OCCC), held in Tokyo in November 2015. Three important questions were identified for discussion prior to the meeting and achieved consensus during the meeting: (i) What are the most important factors to be evaluated prior to initial therapy? (ii) What are the most important factors to be evaluated specifically in recurrent disease? (iii) Are there specific considerations for special patient subpopulations? In addition, we report a list of important unmet needs compiled during the consensus process, which is intended to guide future research initiatives.

ESMO-ESGO-ESTRO Consensus Conference on Endometrial Cancer: diagnosis, treatment and follow-up.

The first joint European Society for Medical Oncology (ESMO), European SocieTy for Radiotherapy & Oncology (ESTRO) and European Society of Gynaecological Oncology (ESGO) consensus conference on endometrial cancer was held on 11-13 December 2014 in Milan, Italy, and comprised a multidisciplinary panel of 40 leading experts in the management of endometrial cancer. Before the conference, the expert panel prepared three clinically relevant questions about endometrial cancer relating to the following four areas: prevention and screening, surgery, adjuvant treatment and advanced and recurrent disease. All relevant scientific literature, as identified by the experts, was reviewed in advance. During the consensus conference, the panel developed recommendations for each specific question and a consensus was reached. Results of this consensus conference, together with a summary of evidence supporting each recommendation, are detailed in this article. All participants have approved this final article.

Long-term significance of urinary neopterin in ovarian cancer: a study by the Austrian Association for Gynecologic Oncology (AGO).

BACKGROUND: Neopterin is produced by activated macrophages upon stimulation with interferon-γ (IFN-γ) and thus, elevated neopterin concentrations in patients indicate cellular inate immune response. Most studies in patients with malignant diseases found an association between higher neopterin concentrations and reduced survival and impaired prognosis. Nevertheless, neopterin is not a classical tumor marker since it is not produced by the cancer cells themselves. PATIENTS AND METHODS: In a study conducted by the Austrian Gynecologic Oncology Group (AGO) in 114 patients with ovarian cystadenomas and 223 patients with invasive ovarian cancer, patients' urinary neopterin was determined before and after primary therapy. The relevance of neopterin in long-term median follow-up was assessed. RESULTS: Elevated levels (cut-off 250 µmol/mol creatinine) were found less frequently in women with benign ovarian cystadenomas (24%) than in patients with malignant disease (58%). After 10 years, only 57% of ovarian cancer patients with elevated urinary neopterin levels survived without disease progression following primary therapy when compared with 86% of women with normal levels (P < 0.001). Along with residual tumor, FIGO stage, age and histological type, neopterin was significantly associated with overall survival (OS) and progression-free survival (PFS). The median PFS was 52 and 12 months and the median OS was 81 and 24 months for patients with normal and elevated neopterin, respectively, P < 0.001. In a multivariate Cox regression analysis, only residual tumor, neopterin and age were independently associated with OS, while only residual tumor was predictive for PFS. Thirty patients with early-stage invasive ovarian cancer (FIGO I and II) were analyzed separately. Of 3 patients with elevated neopterin, 2 died of disease in contrast to 2 out of 27 patients with normal neopterin (P = 0.004). CONCLUSION: In ovarian cancer, the negative impact of elevated urinary neopterin levels indicates a detrimental effect of cancer-associated inflammatory reaction.

Marked improvement in the success rate of medical management of early pregnancy failure following the implementation of a novel institutional protocol and treatment guidelines: a follow-up study.

PURPOSE: To analyze the success rate, time to passage of tissue and subjective patient experience of a newly implemented protocol for medical management of early pregnancy failure (EPF) over a 2-year period. METHODS: A retrospective chart review of all patients with early pregnancy failure primarily opting for medical management was performed. 200 mg mifepristone were administered orally, followed by a single vaginal dose of 800 mcg misoprostol after 36-48 h. We followed-up with our patients using a written questionnaire. RESULTS: 167 women were included in the present study. We observed an overall success rate of 92 %, defined as no need for surgical management after medication administration. We could not identify predictive values for success in a multivariate regression analysis. Most patients (84 %) passed tissue within 6 h after misoprostol administration. The protocol was well tolerated with a low incidence of side effects. Pain was managed well with sufficient analgesics. Responders to the questionnaire felt adequately informed prior to treatment and rated their overall experience as positive. CONCLUSION: The adaption of the institutional medical protocol resulted in a marked improvement of success rate when compared to the previously used protocol (92 vs. 61 %). We credit this increase to the adjusted medication schema as well as to targeted physician education on the expected course and interpretation of outcome measures. Our results underscore that the medical management of EPF is a safe and effective alternative to surgical evacuation in the clinical setting.

Intra- and postoperative catumaxomab in patients with epithelial ovarian cancer: safety and two-year efficacy results from a multicentre, single-arm, phase II study.

BACKGROUND: This is the first study investigating the safety and efficacy of the trifunctional antibody catumaxomab administered i.p. at the end of cytoreductive surgery and postoperatively prior to standard chemotherapy in patients with primary epithelial ovarian cancer (EOC). METHODS: Patients received i.p. catumaxomab 10 µg intraoperatively and 10, 20, 50 and 150 µg on days 7, 10, 13 and 16, respectively, postoperatively. After the study, patients received standard chemotherapy and were followed for 23 months. The primary endpoint was the rate of postoperative complications. RESULTS: Forty-one patients entered the study and were evaluable for safety and 34 were alive at 24 months. Complete tumour resection rate was 68%. Postoperative complications were observed in 51%, the most common anastomotic leakage (7%) and wound infections (5%). The most common catumaxomab-related adverse events were abdominal pain, nausea, vomiting and pyrexia. Thirty-nine percent discontinued catumaxomab therapy, and 98% received chemotherapy post study. Kaplan-Meier estimates of disease-free and overall survival after 24 months were 56% and 85%, respectively. CONCLUSIONS: Intra- and close postoperative catumaxomab seems feasible, but efficacy and safety were limited by postsurgical complications. In the future prospective trials are needed to investigate the best schedule of integration of catumaxomab into current treatment strategies for EOC.

Does thyroid-stimulating hormone influence the prognosis of patients with endometrial cancer? A multicentre trial.

BACKGROUND: Thyroid function has been suggested to interfere with tumour biology and prognosis in different cancers. The present study was performed to investigate the impact of pre-therapeutic serum thyroid-stimulating hormone (TSH) levels on the prognosis of patients with endometrial cancer. METHODS: Pre-therapeutic serum TSH was investigated in 199 patients with endometrial cancer. After stratification in TSH risk groups, univariate and multivariable survival analyses were performed. RESULTS: Elevated TSH was independently associated with poor disease-specific survival in univariate/multivariable survival analyses (P=0.01 and P=0.03, respectively). CONCLUSION: Thyroid-stimulating hormone may serve as a novel and independent prognostic parameter for disease-specific survival in patients with endometrial cancer.

Combined chemotherapy and pembrolizumab salvages multi-chemotherapy agent and avelumab resistant choriocarcinoma: A case report.

Introduction: Gestational trophoblastic neoplasia (GTN) including choriocarcinoma (CC) frequently requires multi-agent chemotherapy to achieve cure. In chemotherapy-resistant GTN, immunotherapy with the checkpoint inhibitors pembrolizumab, avelumab and camrelizumab are potential new treatment options previously described in small case series, phase 2 trials and case reports. Case description: A 32-year-old woman was diagnosed with gestational choriocarcinoma (FIGO score 5). Prior administered therapy regimes included methotrexate, actinomycin-D followed by open hysterectomy with bilateral salpingectomy (histology without GTN) as well as multi-agent chemotherapy and avelumab single-agent. After detection of a suspicious pulmonary mass video- assisted thoracoscopic left lung segmentectomy was performed confirming CC. The patient experienced an intracerebral haemorrhage and was treated with an emergency decompressive craniotomy. The cerebrospinal fluid showed an increased ratio of hCG compared to serum. Therapy with combined escalated etoposide and cisplatin with pembrolizumab was commenced followed by maintenance pembrolizumab achieving a complete hCG response and negative PET CT. Discussion: In the management of multi drug- resistant GTN, application of checkpoint inhibitor pembrolizumab is a new therapeutic strategy. In this heavily pre-treated patient incorporation of pembrolizumab resulted in complete long-term response in a patient who had also failed avelumab therapy.

Prognostic significance of gamma-glutamyltransferase in patients with endometrial cancer: a multi-centre trial.

BACKGROUND: Gamma-glutamyltransferase (GTT), a known marker for apoptotic balance, seems to promote tumour progression, invasion and drug resistance. Recently, high GGT serum levels were shown to be associated with impaired prognosis in patients with cervical cancer. The aim of this study was to investigate the value of pre-therapeutic serum GGT levels as prognostic parameter in patients with endometrial cancer. METHODS: Within the present multi-centre trial, clinical-pathological parameters and pre-therapeutic serum GGT levels were evaluated in 874 consecutive patients with endometrial cancer. Patients were stratified in GGT risk groups, and univariate and multivariable survival analyses were performed. RESULTS: Mean pre-therapeutic serum GGT level was 30.8 (41.5) U l(-1). Elevated and highly elevated serum GGT levels (P=0.03 and P=0.005), tumour stage (P<0.001 and P<0.001), grade (P<0.001 and P=0.02) and age (P<0.001 and P<0.001) were independently associated with progression-free survival in univariate and multivariable survival analyses. Pre-therapeutic GGT was not associated with advanced tumour stage (P=0.6), higher histological grade (P=0.6) or unfavourable histological subtype (P=0.3). CONCLUSION: Pre-therapeutic serum GGT is a novel and independent prognostic parameter for progression-free survival of patients with endometrial cancer. Stratifying patients into prognostic subgroups could be used for patient counselling and individualised treatment planning.

Nomogram prediction for overall survival of patients diagnosed with cervical cancer.

BACKGROUND: Nomograms are predictive tools that are widely used for estimating cancer prognosis. The aim of this study was to develop a nomogram for the prediction of overall survival (OS) in patients diagnosed with cervical cancer. METHODS: Cervical cancer databases of two large institutions were analysed. Overall survival was defined as the clinical endpoint and OS probabilities were estimated using the Kaplan-Meier method. Based on the results of survival analyses and previous studies, relevant covariates were identified, a nomogram was constructed and validated using bootstrap cross-validation. Discrimination of the nomogram was quantified with the concordance probability. RESULTS: In total, 528 consecutive patients with invasive cervical cancer, who had all nomogram variables available, were identified. Mean 5-year OS rates for patients with International Federation of Gynecologists and Obstetricians (FIGO) stage IA, IB, II, III, and IV were 99.0%, 88.6%, 65.8%, 58.7%, and 41.5%, respectively. Seventy-six cancer-related deaths were observed during the follow-up period. FIGO stage, tumour size, age, histologic subtype, lymph node ratio, and parametrial involvement were selected as nomogram covariates. The prognostic performance of the model exceeded that of FIGO stage alone and the model's estimated optimism-corrected concordance probability was 0.723, indicating accurate prediction of OS. We present the prediction model as nomogram and provide a web-based risk calculator (http://www.ccc.ac.at/gcu). CONCLUSION: Based on six easily available parameters, a novel statistical model to predict OS of patients diagnosed with cervical cancer was constructed and validated. The model was implemented in a nomogram and provides accurate prediction of individual patients' prognosis useful for patient counselling and deciding on follow-up strategies.

Final overall survival results of phase III GCIG CALYPSO trial of pegylated liposomal doxorubicin and carboplatin vs paclitaxel and carboplatin in platinum-sensitive ovarian cancer patients.

BACKGROUND: The CALYPSO phase III trial compared CD (carboplatin-pegylated liposomal doxorubicin (PLD)) with CP (carboplatin-paclitaxel) in patients with platinum-sensitive recurrent ovarian cancer (ROC). Overall survival (OS) data are now mature. METHODS: Women with ROC relapsing > 6 months after first- or second-line therapy were randomised to CD or CP for six cycles in this international, open-label, non-inferiority trial. The primary endpoint was progression-free survival. The OS analysis is presented here. RESULTS: A total of 976 patients were randomised (467 to CD and 509 to CP). With a median follow-up of 49 months, no statistically significant difference was observed between arms in OS (hazard ratio = 0.99 (95% confidence interval 0.85, 1.16); log-rank P = 0.94). Median survival times were 30.7 months (CD) and 33.0 months (CP). No statistically significant difference in OS was observed between arms in predetermined subgroups according to age, body mass index, treatment-free interval, measurable disease, number of lines of prior chemotherapy, or performance status. Post-study cross-over was imbalanced between arms, with a greater proportion of patients randomised to CP receiving post-study PLD (68%) than patients randomised to CD receiving post-study paclitaxel (43%; P < 0.001). CONCLUSION: Carboplatin-PLD led to delayed progression and similar OS compared with carboplatin-paclitaxel in platinum-sensitive ROC.

Endocrine therapy plus zoledronic acid in premenopausal breast cancer.

BACKGROUND: Ovarian suppression plus tamoxifen is a standard adjuvant treatment in premenopausal women with endocrine-responsive breast cancer. Aromatase inhibitors are superior to tamoxifen in postmenopausal patients, and preclinical data suggest that zoledronic acid has antitumor properties. METHODS: We examined the effect of adding zoledronic acid to a combination of either goserelin and tamoxifen or goserelin and anastrozole in premenopausal women with endocrine-responsive early breast cancer. We randomly assigned 1803 patients to receive goserelin (3.6 mg given subcutaneously every 28 days) plus tamoxifen (20 mg per day given orally) or anastrozole (1 mg per day given orally) with or without zoledronic acid (4 mg given intravenously every 6 months) for 3 years. The primary end point was disease-free survival; recurrence-free survival and overall survival were secondary end points. RESULTS: After a median follow-up of 47.8 months, 137 events had occurred, with disease-free survival rates of 92.8% in the tamoxifen group, 92.0% in the anastrozole group, 90.8% in the group that received endocrine therapy alone, and 94.0% in the group that received endocrine therapy with zoledronic acid. There was no significant difference in disease-free survival between the anastrozole and tamoxifen groups (hazard ratio for disease progression in the anastrozole group, 1.10; 95% confidence interval [CI], 0.78 to 1.53; P=0.59). The addition of zoledronic acid to endocrine therapy, as compared with endocrine therapy without zoledronic acid, resulted in an absolute reduction of 3.2 percentage points and a relative reduction of 36% in the risk of disease progression (hazard ratio, 0.64; 95% CI, 0.46 to 0.91; P=0.01); the addition of zoledronic acid did not significantly reduce the risk of death (hazard ratio, 0.60; 95% CI, 0.32 to 1.11; P=0.11). Adverse events were consistent with known drug-safety profiles. CONCLUSIONS: The addition of zoledronic acid to adjuvant endocrine therapy improves disease-free survival in premenopausal patients with estrogen-responsive early breast cancer. (ClinicalTrials.gov number, NCT00295646.)