Impact of hormone receptor status and tumor subtypes of breast cancer in young BRCA carriers.

BACKGROUND: Hormone receptor expression is a known positive prognostic and predictive factor in breast cancer; however, limited evidence exists on its prognostic impact on prognosis of young patients harboring a pathogenic variant (PV) in the BRCA1 and/or BRCA2 genes. PATIENTS AND METHODS: This international, multicenter, retrospective cohort study included young patients (aged ≤40 years) diagnosed with invasive breast cancer and harboring germline PVs in BRCA genes. We investigated the impact of hormone receptor status on clinical behavior and outcomes of breast cancer. Outcomes of interest [disease-free survival (DFS), breast cancer-specific survival (BCSS), and overall survival (OS)] were first investigated according to hormone receptor expression (positive versus negative), and then according to breast cancer subtype [luminal A-like versus luminal B-like versus triple-negative versus human epidermal growth factor receptor 2 (HER2)-positive breast cancer]. RESULTS: From 78 centers worldwide, 4709 BRCA carriers were included, of whom 2143 (45.5%) had hormone receptor-positive and 2566 (54.5%) hormone receptor-negative breast cancer. Median follow-up was 7.9 years. The rate of distant recurrences was higher in patients with hormone receptor-positive disease (13.1% versus 9.6%, P < 0.001), while the rate of second primary breast cancer was lower (9.1% versus 14.7%, P < 0.001) compared to patients with hormone receptor-negative disease. The 8-year DFS was 65.8% and 63.4% in patients with hormone receptor-positive and negative disease, respectively. The hazard ratio of hormone receptor-positive versus negative disease changed over time for DFS, BCSS, and OS (P < 0.05 for interaction of hormone receptor status and survival time). Patients with luminal A-like breast cancer had the worst long-term prognosis in terms of DFS compared to all the other subgroups (8-year DFS: 60.8% in luminal A-like versus 63.5% in triple-negative versus 65.5% in HER2-positive and 69.7% in luminal B-like subtype). CONCLUSIONS: In young BRCA carriers, differences in recurrence pattern and second primary breast cancer among hormone receptor-positive versus negative disease warrant consideration in counseling patients on treatment, follow-up, and risk-reducing surgery.

ESO-ESMO fifth international consensus guidelines for breast cancer in young women (BCY5).

We dedicate this manuscript in memory of a dear friend and colleague Bella Kaufman. The fifth International Consensus Symposium for Breast Cancer in Young Women (BCY5) took place virtually in October 2020, organized by the European School of Oncology (ESO) and the European Society of Medical Oncology (ESMO). Consensus recommendations for the management of breast cancer in young women were updated from BCY4 with incorporation of new evidence to inform the guidelines. Areas of research priorities as well as specificities in different geographic and minority populations were identified. This manuscript summarizes the ESO-ESMO international consensus recommendations, which are also endorsed by the European Society of Breast Specialists (EUSOMA).

ESMO Expert Consensus Statements on Cancer Survivorship: promoting high-quality survivorship care and research in Europe.

BACKGROUND: The increased number of cancer survivors and the recognition of physical and psychosocial challenges, present from cancer diagnosis through active treatment and beyond, led to the discipline of cancer survivorship. DESIGN AND METHODS: Herein, we reflected on the different components of survivorship care, existing models and priorities, in order to facilitate the promotion of high-quality European survivorship care and research. RESULTS: We identified five main components of survivorship care: (i) physical effects of cancer and chronic medical conditions; (ii) psychological effects of cancer; (iii) social, work and financial effects of cancer; (iv) surveillance for recurrences and second cancers; and (v) cancer prevention and overall health and well-being promotion. Survivorship care can be delivered by structured care models including but not limited to shared models integrating primary care and oncology services. The choice of the care model to be implemented has to be adapted to local realities. High-quality care should be expedited by the generation of: (i) focused and shared European recommendations, (ii) creation of tools to facilitate implementation of coordinated care and (iii) survivorship educational programs for health care teams and patients. The research agenda should be defined with the participation of health care providers, researchers, policy makers, patients and caregivers. The following patient-centered survivorship research areas were highlighted: (i) generation of a big data platform to collect long-term real-world data in survivors and healthy controls to (a) understand the resources, needs and preferences of patients with cancer, and (b) understand biological determinants of survivorship issues, and (ii) develop innovative effective interventions focused on the main components of survivorship care. CONCLUSIONS: The European Society for Medical Oncology (ESMO) can actively contribute in the efforts of the oncology community toward (a) promoting the development of high-quality survivorship care programs, (b) providing educational material and (c) aiding groundbreaking research by reflecting on priorities and by supporting research networking.

ESO-ESMO 4th International Consensus Guidelines for Breast Cancer in Young Women (BCY4).

The 4th International Consensus Conference for Breast Cancer in Young Women (BCY4) took place in October 2018, in Lugano, Switzerland, organized by the European School of Oncology (ESO) and the European Society of Medical Oncology (ESMO). Consensus recommendations for the management of breast cancer in young women were updated from BCY3 with incorporation of new evidence to inform the guidelines. Areas of research priorities were also identified. This article summarizes the ESO-ESMO international consensus recommendations, which are also endorsed by the European Society of Breast Specialists (EUSOMA).

Differential impact of endocrine therapy and chemotherapy on quality of life of breast cancer survivors: a prospective patient-reported outcomes analysis.

BACKGROUND: In early breast cancer (BC), there has been a trend to escalate endocrine therapy (ET) and to de-escalate chemotherapy (CT). However, the impact of ET versus CT on the quality of life (QoL) of early BC patients is unknown. Here, we characterize the independent contribution of ET and CT on patient-reported outcomes (PROs) at 2 years after diagnosis. PATIENTS AND METHODS: We prospectively collected PROs in 4262 eligible patients using the European Organization for Research and Treatment of Cancer QLQ-C30/BR23 questionnaires inside CANTO trial (NCT01993498). The primary outcome was the C30 summary score (C30-SumSc) at 2 years after diagnosis. RESULTS: From eligible patients, 37.2% were premenopausal and 62.8% postmenopausal; 81.9% received ET and 52.8% CT. In the overall cohort, QoL worsened by 2 years after diagnosis in multiple functions and symptoms; exceptions included emotional function and future perspective, which improved over time. ET (Pint = 0.004), but not CT (Pint = 0.924), had a persistent negative impact on the C30-SumSc. In addition, ET negatively impacted role and social function, pain, insomnia, systemic therapy side-effects, breast symptoms and further limited emotional function and future perspective recovery. Although CT had no impact on the C30-SumSc at 2-years it was associated with deteriorated physical and cognitive function, dyspnea, financial difficulties, body image and breast symptoms. We found a differential effect of treatment by menopausal status; in premenopausal patients, CT, despite only a non-significant trend for deteriorated C30-SumSc (Pint = 0.100), was more frequently associated with QoL domains deterioration than ET, whereas in postmenopausal patients, ET was more frequently associated with QoL deterioration, namely using the C30-SumSc (Pint = 0.004). CONCLUSION(S): QoL deterioration persisted at 2 years after diagnosis with different trajectories by treatment received. ET, but not CT, had a major detrimental impact on C30-SumSc, especially in postmenopausal women. These findings highlight the need to properly select patients for adjuvant ET escalation.

Effectiveness of systemic treatments for pyoderma gangrenosum: a systematic review of observational studies and clinical trials.

BACKGROUND: Pyoderma gangrenosum (PG) is a neutrophilic dermatosis with substantial morbidity. There is no consensus on gold-standard treatments. OBJECTIVES: To review the effectiveness of systemic therapy for PG. METHODS: We searched six databases for 24 systemic therapies for PG. Primary outcomes were complete healing and clinical improvement; secondary outcomes were time to healing and adverse effects. RESULTS: We found 3326 citations and 375 articles underwent full-text review; 41 studies met the inclusion criteria. There were 704 participants in 26 retrospective cohort studies, three prospective cohort studies, seven case series, one case-control study, two open-label trials and two randomized controlled trials (RCTs). Systemic corticosteroids were the most studied (32 studies), followed by ciclosporin (21 studies), biologics (16 studies) and oral dapsone (11 studies). One RCT (STOP-GAP, n = 121) showed that prednisolone and ciclosporin were similar: 15-20% of patients showed complete healing at 6 weeks and 47% at 6 months. Another RCT (n = 30) found that infliximab was superior to placebo at 2 weeks (46% vs. 6% response), with a 21% complete healing rate at 6 weeks. Two uncontrolled trials showed 60% and 37% healing within 4 months for canakinumab and infliximab, respectively; other data suggest that patients with concurrent inflammatory bowel disease may benefit from biologics. The remaining studies were poor quality and had small sample sizes but supported the use of corticosteroids, ciclosporin and biologics. CONCLUSIONS: Systemic corticosteroids, ciclosporin, infliximab and canakinumab had the most evidence in treating PG. However, current literature is limited to small and lower-quality studies with substantial heterogeneity.

Effect of a one-off sporidesmin challenge on the milk production of dairy cows.

AIMS To investigate the effects on milk yield in lactating dairy cows of a single dose of sporidesmin, and to categorise the responses based on clinical signs and differing degrees of liver damage, as assessed by activities of γ-glutamyl transferase (GGT) and post-mortem liver histopathology. METHODS Adult lactating dairy cows (n=17) were given a single intra-ruminal dose of 0.24 mg/kg of sporidesmin dissolved in ethanol and diluted in water on Day 0; an additional three cows served as untreated controls. Weekly serum samples were collected between Days -14 and 42 and analysed for activities of GGT. Milk yields were measured daily over the same period. Cows were subjected to euthanasia due to severe clinical signs (n=2) or were slaughtered at the end of the trial. Samples of livers were examined histologically and were scored for lesions on a scale from 0 (normal) to 3 (severe). Based on GGT activities and clinical observations, cows that were treated with sporidesmin were categorised as non-responders (no clinical signs and normal GGT), subclinical (elevated GGT and no clinical signs) or clinical. Outcomes were compared between these three groups and control cows using generalised additive models. RESULTS Seven cows were classified as clinical, and had median liver scores of 22 (95% CI=20.6-23.4), six were subclinical with median liver scores of 8.7 (95% CI=3.8-13.5) and four were non-responders with median liver scores of 2.5 (95% CI=1.2-4.3). Median liver scores for the three control cows were 1 (95% CI=-0.8-2.1). Activities of GGT increased in subclinical and clinical cows around Day 7. The milk yield of all cows treated with sporidesmin, including non-responder cows, started to decrease on Day 1, and reached a nadir (a drop of between 9 and 85%) on Day 7. CONCLUSIONS AND CLINICAL RELEVANCE It is likely that the overall effects of sporidesmin consumption on milk production by the national herd in New Zealand are hugely underestimated, especially considering its effects on non-responder and subclinical cows as shown in this trial. In view of the results presented here, the authors are suggesting a change to the definition of response to sporidesmin from non-responder, subclinical, and clinical, to subclinical-low, subclinical-high, and clinical, when measuring a combination of GGT activities, clinical signs and milk yields during facial eczema-risk seasons (summer-autumn).

Research needs in breast cancer.

New research questions emerge as medical needs continue to evolve and as we improve our understanding of cancer biology and treatment of malignancies. Although significant advances have been made in some areas of breast cancer research resulting in improvements in therapies and outcomes over the last few decades, other areas have not benefited to the same degree and we continue to have many gaps in our knowledge. This article summarizes the 12 short and medium-term clinical research needs in breast cancer deemed as priorities in 2016 by a panel of experts, in an attempt to focus and accelerate future research in the most needed areas: (i) de-escalate breast cancer therapies in early breast cancer without sacrificing outcomes; (ii) explore optimal adjuvant treatment durations; (iii) develop better tools and strategies to identify patients with genetic predisposition; (iv) improve care in young patients with breast cancer; (v) develop tools to speed up drug development in biomarker-defined populations; (vi) identify and validate targets that mediate resistance to chemotherapy, endocrine therapy and anti-HER2 therapies; (vii) evaluate the efficacy of local-regional treatments for metastatic disease; (viii) better define the optimal sequence of treatments in the metastatic setting; (ix) evaluate the clinical impact of intra-patient heterogeneity (intra-tumor, inter-tumor and inter-lesion heterogeneity); (x) better understand the biology and identify new targets in triple-negative breast cancer; (xi) better understand immune surveillance in breast cancer and further develop immunotherapies; and (xii) increase survivorship research efforts including supportive care and quality of life.

De-escalating and escalating treatments for early-stage breast cancer: the St. Gallen International Expert Consensus Conference on the Primary Therapy of Early Breast Cancer 2017.

The 15th St. Gallen International Breast Cancer Conference 2017 in Vienna, Austria reviewed substantial new evidence on loco-regional and systemic therapies for early breast cancer. Treatments were assessed in light of their intensity, duration and side-effects, seeking where appropriate to escalate or de-escalate therapies based on likely benefits as predicted by tumor stage and tumor biology. The Panel favored several interventions that may reduce surgical morbidity, including acceptance of 2 mm margins for DCIS, the resection of residual cancer (but not baseline extent of cancer) in women undergoing neoadjuvant therapy, acceptance of sentinel node biopsy following neoadjuvant treatment of many patients, and the preference for neoadjuvant therapy in HER2 positive and triple-negative, stage II and III breast cancer. The Panel favored escalating radiation therapy with regional nodal irradiation in high-risk patients, while encouraging omission of boost in low-risk patients. The Panel endorsed gene expression signatures that permit avoidance of chemotherapy in many patients with ER positive breast cancer. For women with higher risk tumors, the Panel escalated recommendations for adjuvant endocrine treatment to include ovarian suppression in premenopausal women, and extended therapy for postmenopausal women. However, low-risk patients can avoid these treatments. Finally, the Panel recommended bisphosphonate use in postmenopausal women to prevent breast cancer recurrence. The Panel recognized that recommendations are not intended for all patients, but rather to address the clinical needs of the majority of common presentations. Individualization of adjuvant therapy means adjusting to the tumor characteristics, patient comorbidities and preferences, and managing constraints of treatment cost and access that may affect care in both the developed and developing world.

Risk of acute myeloid leukemia and myelodysplastic syndrome among older women receiving anthracycline-based adjuvant chemotherapy for breast cancer on Modern Cooperative Group Trials (Alliance A151511).

PURPOSE: We examined acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS) events among 9679 women treated for breast cancer on four adjuvant Alliance for Clinical Trials in Oncology trials with >90 months of follow-up in order to better characterize the risk for AML/MDS in older patients receiving anthracyclines. METHODS: We used multivariable Cox regression to examine factors associated with AML/MDS, adjusting for age (≥65 vs. <65 years; separately for ≥70 vs. <70 years), race/ethnicity, insurance, performance status, and anthracycline receipt. We also examined the effect of cyclophosphamide, the interaction of anthracycline and age, and outcomes for those developing AML/MDS. RESULTS: On Cancer and Leukemia Group B (CALGB) 40101, 49907, 9344, and 9741, 7290 received anthracyclines; 15% were in the age ≥65 and 7% were ≥70. Overall, 47 patients developed AML/MDS (30 AML [0.3%], 17 MDS [0.2%]); 83% of events occurred within 5 years of study registration. Among those age ≥65 and ≥70, 0.8 and 1.0% developed AML/MDS (vs. 0.4% for age <65), respectively. In adjusted analyses, older age and anthracycline receipt were significantly associated with AML/MDS (adjusted hazard ratio [HR] for age ≥65 [vs. <65] = 3.13, 95% confidence interval [CI] 1.18-8.33; HR for anthracycline receipt [vs. no anthracycline] = 5.16, 95% CI 1.47-18.19). There was no interaction between age and anthracycline use. Deaths occurred in 70% of those developing AML/MDS. CONCLUSIONS: We observed an increased risk for AML/MDS for older patients and those receiving anthracyclines, though these events were rare. Our results help inform discussions surrounding anticipated toxicities of adjuvant chemotherapy in older patients.

Factors affecting uptake and adherence to breast cancer chemoprevention: a systematic review and meta-analysis.

BACKGROUND: Preventive therapy is a risk reduction option for women who have an increased risk of breast cancer. The effectiveness of preventive therapy to reduce breast cancer incidence depends on adequate levels of uptake and adherence to therapy. We aimed to systematically review articles reporting uptake and adherence to therapeutic agents to prevent breast cancer among women at increased risk, and identify the psychological, clinical and demographic factors affecting these outcomes. DESIGN: Searches were carried out in PubMed, CINAHL, EMBASE and PsychInfo, yielding 3851 unique articles. Title, abstract and full text screening left 53 articles, and a further 4 studies were identified from reference lists, giving a total of 57. This review was prospectively registered with PROSPERO (CRD42014014957). RESULTS: Twenty-four articles reporting 26 studies of uptake in 21 423 women were included in a meta-analysis. The pooled uptake estimate was 16.3% [95% confidence interval (CI) 13.6-19.0], with high heterogeneity (I(2) = 98.9%, P < 0.001). Uptake was unaffected by study location or agent, but was significantly higher in trials [25.2% (95% CI 18.3-32.2)] than in non-trial settings [8.7% (95% CI 6.8-10.9)] (P < 0.001). Factors associated with higher uptake included having an abnormal biopsy, a physician recommendation, higher objective risk, fewer side-effect or trial concerns, and older age. Adherence (day-to-day use or persistence) over the first year was adequate. However, only one study reported a persistence of ≥ 80% by 5 years. Factors associated with lower adherence included allocation to tamoxifen (versus placebo or raloxifene), depression, smoking and older age. Risk of breast cancer was discussed in all qualitative studies. CONCLUSION: Uptake of therapeutic agents for the prevention of breast cancer is low, and long-term persistence is often insufficient for women to experience the full preventive effect. Uptake is higher in trials, suggesting further work should focus on implementing preventive therapy within routine care.

Ovarian suppression using luteinizing hormone-releasing hormone agonists during chemotherapy to preserve ovarian function and fertility of breast cancer patients: a meta-analysis of randomized studies.

BACKGROUND: The role of temporary ovarian suppression with luteinizing hormone-releasing hormone agonists (LHRHa) in the prevention of chemotherapy-induced premature ovarian failure (POF) is still controversial. Our meta-analysis of randomized, controlled trials (RCTs) investigates whether the use of LHRHa during chemotherapy in premenopausal breast cancer patients reduces treatment-related POF rate, increases pregnancy rate, and impacts disease-free survival (DFS). METHODS: A literature search using PubMed, Embase, and the Cochrane Library, and the proceedings of major conferences, was conducted up to 30 April 2015. Odds ratios (ORs) and 95% confidence intervals (CIs) for POF (i.e. POF by study definition, and POF defined as amenorrhea 1 year after chemotherapy completion) and for patients with pregnancy, as well hazard ratios (HRs) and 95% CI for DFS, were calculated for each trial. Pooled analysis was carried out using the fixed- and random-effects models. RESULTS: A total of 12 RCTs were eligible including 1231 breast cancer patients. The use of LHRHa was associated with a significant reduced risk of POF (OR 0.36, 95% CI 0.23-0.57; P < 0.001), yet with significant heterogeneity (I(2) = 47.1%, Pheterogeneity = 0.026). In eight studies reporting amenorrhea rates 1 year after chemotherapy completion, the addition of LHRHa reduced the risk of POF (OR 0.55, 95% CI 0.41-0.73, P < 0.001) without heterogeneity (I(2) = 0.0%, Pheterogeneity = 0.936). In five studies reporting pregnancies, more patients treated with LHRHa achieved pregnancy (33 versus 19 women; OR 1.83, 95% CI 1.02-3.28, P = 0.041; I(2) = 0.0%, Pheterogeneity = 0.629). In three studies reporting DFS, no difference was observed (HR 1.00, 95% CI 0.49-2.04, P = 0.939; I(2) = 68.0%, Pheterogeneity = 0.044). CONCLUSION: Temporary ovarian suppression with LHRHa in young breast cancer patients is associated with a reduced risk of chemotherapy-induced POF and seems to increase the pregnancy rate, without an apparent negative consequence on prognosis.

Drug withdrawal in women with progressive metastatic breast cancer while on aromatase inhibitor therapy.

BACKGROUND: Acquiring resistance to endocrine therapy is common in metastatic hormone-receptor-positive breast cancer (MBC). These patients most often transition either to next-line endocrine therapy or to systemic chemotherapy. However, withdrawal of endocrine therapy and observation as is selectively practiced in prostate cancer is another potential strategy for breast cancer patients. METHODS: A prospective, single-arm phase II trial of aromatase inhibitor (AI) withdrawal was performed in women with MBC, who had disease progression on AI therapy. The primary objective was to estimate the clinical benefit rate (defined as complete or partial response, or stable disease for at least 24 weeks, by RECIST criteria). Participants were monitored clinically and radiographically off all therapy at 8, 16 and 24 weeks after treatment and every 12 weeks thereafter until disease progression. RESULTS: Twenty-four patients (of 40 intended) were enrolled when the study was closed due to slow accrual. Clinical benefit rate overall was 46% (95% CI 26% to 67%). Median progression-free survival from time of AI withdrawal was 4 months. Two patients have remained progression free, off all treatment, for over 60 months. CONCLUSIONS: Despite suboptimal patient accrual, our results suggest that selected patients with metastatic breast cancer progressing on AI therapy can experience disease stabilisation and a period of observation after AI withdrawal. A randomised phase II trial is planned.

Genetic variant predicts bevacizumab-induced hypertension in ECOG-5103 and ECOG-2100.

BACKGROUND: Bevacizumab has broad anti-tumour activity, but substantial risk of hypertension. No reliable markers are available for predicting bevacizumab-induced hypertension. METHODS: A genome-wide association study (GWAS) was performed in the phase III bevacizumab-based adjuvant breast cancer trial, ECOG-5103, to evaluate for an association between genotypes and hypertension. GWAS was conducted in those who had experienced systolic blood pressure (SBP) >160 mm Hg during therapy using binary analysis and a cumulative dose model for the total exposure of bevacizumab. Common toxicity criteria (CTC) grade 3-5 hypertension was also assessed. Candidate SNP validation was performed in the randomised phase III trial, ECOG-2100. RESULTS: When using the phenotype of SBP>160 mm Hg, the most significant association in SV2C (rs6453204) approached and met genome-wide significance in the binary model (P=6.0 × 10(-8); OR=3.3) and in the cumulative dose model (P=4.7 × 10(-8); HR=2.2), respectively. Similar associations with rs6453204 were seen for CTC grade 3-5 hypertension but did not meet genome-wide significance. Validation study from ECOG-2100 demonstrated a statistically significant association between this SNP and grade 3/4 hypertension using the binary model (P-value=0.037; OR=2.4). CONCLUSIONS: A genetic variant in SV2C predicted clinically relevant bevacizumab-induced hypertension in two independent, randomised phase III trials.

Utility of gonadotropin-releasing hormone agonists for fertility preservation in young breast cancer patients: the benefit remains uncertain.

BACKGROUND: Breast cancer in young women is typically characterised by aggressive disease, and treatment with adjuvant chemotherapy is generally recommended. Chemotherapy has conferred significant improvements in disease-free and overall survival for young women with breast cancer; however, with improved cure rates, long-term adverse effects of cytotoxic treatment, such as premature ovarian failure (POF) and infertility, have become increasingly important. A potential fertility preservation strategy is administration of gonadotropin-releasing hormone agonists (GnRHas) during adjuvant chemotherapy. DESIGN: This review analyses and summarises the current evidence for use of GnRHa in preserving ovarian function in young breast cancer patients. RESULTS: Twelve trials, both non-randomised and randomised, have now been conducted assessing GnRHas in fertility preservation in young breast cancer patients, with conflicting results. Limitations of the current data include the use of poorly sensitive end points for fertility preservation, variable age of enrolled patients and limited pregnancy data. CONCLUSION: The utility of GnRHa as a fertility preservation strategy remains uncertain, and use outside of a clinical trial generally not recommended. Further research into this under-recognised issue is vital.

Predictors of recovery of ovarian function during aromatase inhibitor therapy.

BACKGROUND: Aromatase inhibitors (AIs) may cause a rise in estrogen levels due to ovarian function recovery in women with clinical chemotherapy-induced ovarian failure (CIOF). We carried out a prospective registry trial to identify predictors of ovarian function recovery during AI therapy. PATIENTS AND METHODS: Women with hormone receptor (HR)-positive breast cancer who remained amenorrheic and had hormonal levels consistent with ovarian failure after adjuvant chemotherapy were enrolled in a multi-institutional clinical trial of anastrozole. Subjects underwent frequent assessment using an ultrasensitive estradiol assay. Multivariable analysis was used to evaluate clinical and biochemical predictors of ovarian function recovery within 48 weeks. RESULTS: Recovery of ovarian function during AI therapy was observed in 13 of 45 (28.9%) assessable subjects after a median 2.1 months (range 0.6-11.9). Median age at chemotherapy initiation was statistically significantly different between those who regained ovarian function (43 years, range 40-51) and those who remained postmenopausal (49 years, range 44-52; P < 0.0001). CONCLUSIONS: A significant proportion of women with CIOF recover ovarian function during AI therapy, including a woman over age 50 at initiation of chemotherapy. Tamoxifen remains the standard of care for women with CIOF. If an AI is used, patients should be monitored frequently with high-quality estradiol assays. CLINICALTRIALS.GOV: NCT00555477.