Nine-Week Versus One-Year Trastuzumab for Early Human Epidermal Growth Factor Receptor 2-Positive Breast Cancer: 10-Year Update of the ShortHER Phase III Randomized Trial.

Clinical trials frequently include multiple end points that mature at different times. The initial report, typically based on the primary end point, may be published when key planned coprimary or secondary analyses are not yet available. Clinical trial updates provide an opportunity to disseminate additional results from studies, published in JCO or elsewhere, for which the primary end point has already been reported.We present the final analysis of the phase III noninferiority, randomized ShortHER trial comparing 9 weeks versus 1 year of adjuvant trastuzumab with chemotherapy in patients with human epidermal growth factor receptor 2-positive (HER2+) early breast cancer (BC). Women with HER2+ BC were randomly assigned to anthracycline-taxane combinations plus 1-year trastuzumab (arm A, long) or 9-week trastuzumab (arm B, short). Here, we report the second coprimary end point overall survival (OS), updated disease-free survival (DFS), and outcomes according to hormone receptor status, age, and nodal status. At a median follow-up of 9 years, 10-year DFS is 77% versus 78% in the long versus short arm, respectively. Ten-year OS is 89% versus 88% in the long versus short arm, respectively. 10-year DFS rates in the long versus short arm according to nodal status are N0 81% versus 85%; N1-3 77% versus 79%; and N4+ 63% versus 53%. Ten-year OS rates in long versus short arm according to nodal status are N0 89% versus 95%%; N1-3 92% versus 89%; and N4+ 84% versus 64%. The updated analysis of the ShortHER trial shows that 1-year trastuzumab is the standard treatment for patients with HER2+ early BC as noninferiority cannot be claimed. However, numerically, the differences for the patients at low or intermediate risk (N0/N1-3) is negligible, while patients with N4+ have a clear benefit with 1-year trastuzumab.

The Value of Semiquantitative Parameters Derived from 18F-FDG PET/CT for Predicting Response to Neoadjuvant Chemotherapy in a Cohort of Patients with Different Molecular Subtypes of Breast Cancer.

Pathological complete response (pCR) after neoadjuvant chemotherapy (NAC) is a strong prognostic factor in breast cancer (BC). The aim of this study was to investigate whether semiquantitative parameters derived from baseline [18F]Fluorodeoxyglucose ([18F]FDG) positron emission computed tomography/computed tomography (PET/CT) could predict pCR after NAC and survival outcomes in patients affected by different molecular subtypes of BC. We retrospectively retrieved patients from the databases of two Italian hospitals (Centre A: University Hospital of Ferrara; Centre B: University of Padua) meeting the following inclusion criteria: (1) diagnosis of BC; (2) history of NAC; (3) baseline [18F]FDG PET/CT performed before the first cycle of NAC; (4) available follow-up data (response after NAC and survival information). For each [18F]FDG PET/CT scan, semiquantitative parameters (SUVmax, SUVmean, MTV and TLG) related to the primary tumor (B), to the reference lesion for both axillary (N) and distant lymph node (DN), and to the whole-body burden of disease (WB) were evaluated. Patients enrolled were 133: 34 from centre A and 99 from centre B. Patients' molecular subtypes were: 9 luminal A, 49 luminal B, 33 luminal B + HER-2, 10 HER-2 enriched, and 32 triple negative (TNBC). Luminal A and HER-2 enriched BC patients were excluded from the analysis due to the small sample size. pCR after NAC was achieved in 47 patients (41.2%). [18F]FDG PET/CT detected the primary tumor in 98.3% of patients and lymph node metastases were more frequently detected in Luminal B subgroup. Among Luminal B patients, median SUVmean_B values were significantly higher (p = 0.027) in responders (7.06 ± 5.9) vs. non-responders (4.4 ± 2.1) to NAC. Luminal B + HER-2 non-responders showed a statistically significantly higher median MTV_B (7.3 ± 4.2 cm3 vs. 3.5 ± 2.5 cm3; p = 0.003) and TLG_B (36.5 ± 24.9 vs. 18.9 ± 17.7; p = 0.025) than responders at baseline [18F]FDG PET/CT. None of the semiquantitative parameters predicted pCR after NAC in TNBC patients. However, among TNBC patients who achieved pCR after NAC, 4 volumetric parameters (MTV_B, TLG_B, MTV_WB and TLG_WB) were significantly higher in patients dead at follow-up. If confirmed in further studies, these results could open up a widespread use of [18F]FDG PET/CT as a baseline predictor of response to NAC in luminal B and luminal B + HER-2 patients and as a prognostic tool in TNBC.

Impact on the long-term prognosis of FDG PET/CT in luminal-A and luminal-B breast cancer.

PURPOSE: The aim of the present study was to explore the prognostic role of 2- deoxy-2-[18F]fluoro-D-glucose PET (FDG PET)/CT in recurrent luminal A and luminal B breast cancer. MATERIALS AND METHODS: From two institutional databases, we retrospectively retrieved data about breast cancer patients undergoing FDG PET/CT between 2011 and 2018 for the assessment of recurrency. Molecular subtypes of breast cancer were defined based on the expression of estrogen, progesterone, human epidermal growth factor receptor 2 (HER2)-b receptors and proliferation index. Overall survival (OS, intended as the time from PET/CT and the time of death) was registered for each patient, by checking the medical charts. Parametric and survival analyses were computed. RESULTS: Data of 179 patients were retrieved. Sixty-three patients had luminal A, 88 luminal B and 28 luminal B/He breast cancer. At the time of PET/CT scan, cancer antigen (CA) 15.3 levels was within the normal range in 119 patients, whereas it was increased in 60 patients. FDG PET/CT results were suggestive for disease recurrence in 114 (63.7%) patients. The median time lapse from the FDG PET/CT scan to the last clinical follow-up visit was 51 months (1-192 months). Patients with evidence of a PET/CT scan suggestive for disease recurrence showed a significantly shorter OS (P < 0.001) compared to patients with no PET/CT evidence of recurrence, in each subset of luminal breast cancer. Moreover, PET/CT was able to stratify the prognosis of patients independently from the level of tumor marker. CONCLUSION: These data suggest that FDG PET/CT may be an attractive prognostic tool in recurrent breast cancer. Our study supports its prognostic role both in luminal A and B-type molecular subtypes, regardless of the CA 15.3 levels.

Is There Still a Role for Endocrine Therapy Alone in HR+/HER2- Advanced Breast Cancer Patients? Results from the Analysis of Two Data Sets of Patients Treated with High-Dose Fulvestrant as First-Line Therapy in the Real-World Setting: The EVA and GIM-13 AMBRA Studies.

BACKGROUND: Different studies suggest that fulvestrant 500 mg every 28 days (HD-FUL) could be an active treatment in HR+ advanced breast cancer (ABC) patients even treated with aromatase inhibitors in the adjuvant setting. The aim of this analysis is to describe the outcome of ABC patients treated with HD-FUL as first-line treatment in terms of median duration of treatment and the overall response rate in a real-world setting. METHODS: For the purpose of the present analysis, we considered two data sets of HR+ ABC patients collected in Italy between 2012 and 2015 (EVA and GIM-13 AMBRA studies). RESULTS: Eighty-one and 91 patients have been identified from the two data sets. The median age was 63 years (range 35-82) for the EVA and 57.8 years (range 35.0-82.3) for the AMBRA patients. ORRs were 23.5 and 24.3% in the whole population, 26.9% in the patients with bone only, and 21.8 and 21.4% in those with visceral metastases. The median duration of HD-FUL was 11.6 months (range 1-48) and 12.4 months (range 2.9-70.0) in the two data sets, respectively. CONCLUSION: These data suggest that HD-FUL should still continue to play a significant role as first-line therapy in HR+ ABC patients.

Netupitant/palonosetron (NEPA) and dexamethasone for prevention of emesis in breast cancer patients receiving adjuvant anthracycline plus cyclophosphamide: a multi-cycle, phase II study.

BACKGROUND: NEPA is an oral fixed-dose combination of netupitant, a new highly selective neurokinin-1 receptor antagonist, and palonosetron. This study was conducted to evaluate whether the efficacy of NEPA against chemotherapy-induced nausea and vomiting (CINV) in cycle 1 would be maintained over subsequent chemotherapy cycles in breast cancer patients receiving adjuvant anthracycline plus cyclophosphamide (AC). The study also describes the relationship between efficacy on day 1 through 5 (overall period) and control of CINV on day 6 through 21 (very late period) in each cycle. METHODS: In this multicentre, phase II study, patients received both NEPA and dexamethasone (12 mg intravenously) just before chemotherapy. The primary efficacy endpoint was overall complete response (CR; no emesis and no rescue medication use) in cycle 1. Sustained efficacy was evaluated during the subsequent cycles by calculating the rate of CR in cycles 2-4 and by assessing the probability of sustained CR over multiple cycles. The impact of both overall CR and risk factors for CINV on the control of very late events (vomiting and moderate-to-severe nausea) were also examined. RESULTS: Of the 149 patients enrolled in the study, 139 were evaluable for a total of 552 cycles; 97.8% completed all 4 cycles. The proportion of patients with an overall CR was 70.5% (90% CI, 64.1 to 76.9) in cycle 1, and this was maintained in subsequent cycles. The cumulative percentage of patients with a sustained CR over 4 cycles was 53%. NEPA was well tolerated across cycles. In each cycle, patients with CR experienced a significantly better control of very late CINV events than those who experienced no CR. Among the patients with CR, the only predictor for increased likelihood of developing very late CINV was pre-chemotherapy (anticipatory) nausea (adjusted odds ratio = 0.65-0.50 for no CINV events on cycles 3 and 4). CONCLUSION: The high anti-emetic efficacy seen with the NEPA regimen in the first cycle was maintained over multiple cycles of adjuvant AC for breast cancer. Preliminary evidence also suggests that patients achieving a CR during the overall period gain high protection even against very late CINV events in each chemotherapy cycle. TRIAL REGISTRATION: This trial was retrospectively registered at Clinicaltrials.gov identifier (NCT03862144) on 05/Mar/2019.

Phase II Study of Dehydroepiandrosterone in Androgen Receptor-Positive Metastatic Breast Cancer.

LESSONS LEARNED: The androgen receptor (AR) is present in most breast cancers (BC), but its exploitation as a therapeutic target has been limited.This study explored the activity of dehydroepiandrosterone (DHEA), a precursor being transformed into androgens within BC cells, in combination with an aromatase inhibitor (to block DHEA conversion into estrogens), in a two-stage phase II study in patients with AR-positive/estrogen receptor-positive/human epidermal growth receptor 2-negative metastatic BC.Although well tolerated, only 1 of 12 patients obtained a prolonged clinical benefit, and the study was closed after its first stage for poor activity. BACKGROUND: Androgen receptors (AR) are expressed in most breast cancers, and AR-agonists have some activity in these neoplasms. We investigated the safety and activity of the androgen precursor dehydroepiandrosterone (DHEA) in combination with an aromatase inhibitor (AI) in patients with AR-positive metastatic breast cancer (MBC). METHODS: A two-stage phase II study was conducted in two patient cohorts, one with estrogen receptor (ER)-positive (resistant to AIs) and the other with triple-negative MBC. DHEA 100 mg/day was administered orally. The combination with an AI aimed to prevent the conversion of DHEA into estrogens. The main endpoint was the clinical benefit rate. The triple-negative cohort was closed early. RESULTS: Twelve patients with ER-positive MBC were enrolled. DHEA-related adverse events, reported in four patients, included grade 2 fatigue, erythema, and transaminitis, and grade 1 drowsiness and musculoskeletal pain. Clinical benefit was observed in one patient with ER-positive disease whose tumor had AR gene amplification. There was wide inter- and intra-patient variation in serum levels of DHEA and its metabolites. CONCLUSION: DHEA showed excellent safety but poor activity in MBC. Although dose and patient selection could be improved, high serum level variability may hamper further DHEA development in this setting.

Correction: Everolimus (EVE) and exemestane (EXE) in patients with advanced breast cancer aged ≥ 65 years: new lessons for clinical practice from the EVA study.

[This corrects the article DOI: 10.18632/oncotarget.25874.].

High-sensitivity assay for monitoring ESR1 mutations in circulating cell-free DNA of breast cancer patients receiving endocrine therapy.

Approximately 70% of breast cancers (BCs) express estrogen receptor alpha (ERα) and are treated with endocrine therapy. However, the effectiveness of this therapy is limited by innate or acquired resistance in approximately one-third of patients. Activating mutations in the ESR1 gene that encodes ERα promote critical resistance mechanisms. Here, we developed a high sensitivity approach based on enhanced-ice-COLD-PCR for detecting ESR1 mutations. The method produced an enrichment up to 100-fold and allowed the unambiguous detection of ESR1 mutations even when they consisted of only 0.01% of the total ESR1 allelic fraction. After COLD-PCR enrichment, methods based on next-generation sequencing or droplet-digital PCR were employed to detect and quantify ESR1 mutations. We applied the method to detect ESR1 mutations in circulating free DNA from the plasma of 56 patients with metastatic ER-positive BC. Fifteen of these patients were found to have ESR1 mutations at codons 536-538. This study demonstrates the utility of the enhanced-ice-COLD-PCR approach for simplifying and improving the detection of ESR1 tumor mutations in liquid biopsies. Because of its high sensitivity, the approach may potentially be applicable to patients with non-metastatic disease.

Correction 2: Everolimus (EVE) and exemestane (EXE) in patients with advanced breast cancer aged ≥ 65 years: new lessons for clinical practice from the EVA study.

[This corrects the article DOI: 10.18632/oncotarget.25874.].

Buparlisib plus fulvestrant in postmenopausal women with hormone-receptor-positive, HER2-negative, advanced breast cancer progressing on or after mTOR inhibition (BELLE-3): a randomised, double-blind, placebo-controlled, phase 3 trial.

BACKGROUND: Activation of the PI3K/AKT/mTOR pathway occurs frequently in breast cancer that is resistant to endocrine therapy. Approved mTOR inhibitors effectively inhibit cell growth and proliferation but elicit AKT phosphorylation via a feedback activation pathway, potentially leading to resistance to mTOR inhibitors. We evaluated the efficacy and safety of buparlisib plus fulvestrant in patients with advanced breast cancer who were pretreated with endocrine therapy and mTOR inhibitors. METHODS: BELLE-3 was a randomised, double-blind, placebo-controlled, multicentre, phase 3 study. Postmenopausal women aged 18 years or older with histologically or cytologically confirmed hormone-receptor-positive, HER2-negative, locally advanced or metastatic breast cancer, who had relapsed on or after endocrine therapy and mTOR inhibitors, were recruited from 200 trial centres in 22 countries. Eligible patients were randomly assigned (2:1) via interactive response technology (block size of six) to receive oral buparlisib (100 mg per day) or matching placebo starting on day 1 of cycle 1, plus intramuscular fulvestrant (500 mg) on days 1 and 15 of cycle 1 and on day 1 of subsequent 28-day cycles. Randomisation was stratified by visceral disease status. The primary endpoint was progression-free survival by local investigator assessment as per the Response Evaluation Criteria In Solid Tumors (RECIST) version 1.1 in the full analysis population (all randomised patients, by intention-to-treat). Safety was analysed in all patients who received at least one dose of treatment and at least one post-baseline safety assessment. This study is registered with ClinicalTrials.gov, number NCT01633060, and is ongoing but no longer enrolling patients. FINDINGS: Between Jan 15, 2013, and March 31, 2016, 432 patients were randomly assigned to the buparlisib (n=289) or placebo (n=143) groups. Median progression-free survival was significantly longer in the buparlisib versus placebo group (3·9 months [95% CI 2·8-4·2] vs 1·8 months [1·5-2·8]; hazard ratio [HR] 0·67, 95% CI 0·53-0·84, one-sided p=0·00030). The most frequent grade 3-4 adverse events in the buparlisib versus placebo group were elevated alanine aminotransferase (63 [22%] of 288 patients vs four [3%] of 140), elevated aspartate aminotransferase (51 [18%] vs four [3%]), hyperglycaemia (35 [12%] vs none), hypertension (16 [6%] vs six [4%]), and fatigue (ten [3%] vs two [1%]). Serious adverse events were reported in 64 (22%) of 288 patients in the buparlisib group versus 23 (16%) of 140 in the placebo group; the most frequent serious adverse events (affecting ≥2% of patients) were elevated aspartate aminotransferase (six [2%] vs none), dyspnoea (six [2%] vs one [1%]), and pleural effusion (six [2%] vs none). On-treatment deaths occurred in ten (3%) of 288 patients in the buparlisib group and in six (4%) of 140 in the placebo group; most deaths were due to metastatic breast cancer, and two were considered treatment-related (cardiac failure [n=1] in the buparlisib group and unknown reason [n=1] in the placebo group). INTERPRETATION: The safety profile of buparlisib plus fulvestrant does not support its further development in this setting. Nonetheless, the efficacy of buparlisib supports the rationale for the use of PI3K inhibitors plus endocrine therapy in patients with PIK3CA mutations. FUNDING: Novartis Pharmaceuticals Corporation.

Resource utilization and cost saving analysis of subcutaneous versus intravenous trastuzumab in early breast cancer patients.

We conducted an economic evaluation of intravenous (IV) vs subcutaneous (SC) trastuzumab for the treatment of patients with early breast cancer (EBC). Data of patients receiving adjuvant IV trastuzumab at our institute in 2014 were used to study three different treatment scenarios: 1) IV trastuzumab, 2) SC trastuzumab, and 3) IV trastuzumab during chemotherapy followed by SC trastuzumab. Our cohort included 114 patients with a median weight of 63.75 kg. Scenario 2 was the most time-saving treatment, with 71.7% reduction in preparation time and 89.3% reduction in chair time compared to scenario 1. Considering full costs, the mean costs per patient/year were € 14,233 ± 8,698 for scenario 1, € 14,272 ± 8,312 for scenario 2, and € 14,535 ± 8,646 for scenario 3 (p = 0.959). When mean body weight was > 65.2 kg, the mean cost was lower in scenario 2 than in scenario 1. Scenario 2 proved a valuable time-saving and cost-saving option. A shift from IV to SC trastuzumab should be considered, especially in capacity-constrained oncology departments.

Everolimus Plus Exemestane in Advanced Breast Cancer: Safety Results of the BALLET Study on Patients Previously Treated Without and with Chemotherapy in the Metastatic Setting.

BACKGROUND: The BALLET study was an open-label, multicenter, expanded access study designed to allow treatment with everolimus plus exemestane in postmenopausal women with hormone receptor-positive metastatic breast cancer progressed following prior endocrine therapy. A post hoc analysis to evaluate if previous chemotherapy in the metastatic setting affects the safety profile of the combination regimen of everolimus and exemestane was conducted on the Italian subset, as it represented the major part of the patients enrolled (54%). PATIENTS AND METHODS: One thousand one hundred and fifty-one Italian patients were included in the present post hoc analysis, which focused on two sets of patients: patients who never received chemotherapy in the metastatic setting (36.1%) and patients who received at least one chemotherapy treatment in the metastatic setting (63.9%). RESULTS: One thousand one hundred and sixteen patients (97.0%) prematurely discontinued the study drug, and the main reasons reported were disease progression (39.1%), local reimbursement of everolimus (31.1%), and adverse events (AEs) (16.1%). The median duration of study treatment exposure was 139.5 days for exemestane and 135.0 days for everolimus. At least one AE was experienced by 92.5% of patients. The incidence of everolimus-related AEs was higher (83.9%) when compared with those that occurred with exemestane (29.1%), and the most commonly reported everolimus-related AE was stomatitis (51.3%). However, no significant difference in terms of safety related to the combination occurred between patients without and with chemotherapy in the metastatic setting. CONCLUSION: Real-life data of the Italian patients BALLET-related cohort were an adequate setting to state that previous chemotherapy did not affect the safety profile of the combination regimen of everolimus and exemestane. IMPLICATIONS FOR PRACTICE: With the advent of new targeted agents for advanced or metastatic breast cancer, multiple lines of therapy may be possible, and components of the combined regimens can overlap from one line to another. Thus, it is important to assess even the potential of cumulative and additive toxic effects among the drugs. Previous chemotherapy did not affect the safety profile of the combination regimen of everolimus and exemestane. The continuous monitoring of the safety signals of this drug combination from general clinical practice is important, in particular for stomatitis.

Phase Ib dose-finding trial of lapatinib plus pegylated liposomal doxorubicin in advanced HER2-positive breast cancer.

PURPOSE: Combination of anthracyclines with trastuzumab is hampered by cardiotoxicity. Pegylated liposomal doxorubicin and lapatinib could represent a safer alternative to combination therapy. METHODS: In this phase Ib study with 3 + 3 dose escalation design, patients with HER2-positive advanced breast cancer received pegylated liposomal doxorubicin 30 mg/m2 intravenously on day 1 plus lapatinib 1250 (level 1) or 1500 (level 2) mg/day orally on days 1-21 of each 21-day cycle. The aims were to establish the maximum tolerated dose at first cycle, and the activity and safety of multiple cycles. RESULTS: Nine patients out of 11 enrolled were evaluable: 3 at level 1 and 6 at level 2. No dose-limiting toxicities occurred at dose level 1, while 1 (grade 3 diarrhea) occurred at dose level 2, leading to the expansion of this cohort to 6 patients, with no further dose-limiting toxicities. Main grade 1-2 toxicities at first cycle were leucopenia, diarrhea, elevated transaminases, mucositis. Three patients had grade 3 toxicities at subsequent cycles, including colitis, anorexia, stomatitis plus hand-foot syndrome. One partial response, 5 disease stabilizations, and 3 disease progressions were reported. CONCLUSIONS: Combination of pegylated liposomal doxorubicin and lapatinib is feasible and potentially active in pretreated HER2-positive advanced breast cancer patients. TRIAL REGISTRATION: NCT02131506 (ClinicalTrials.gov identifier).

Sorafenib for the treatment of breast cancer.

INTRODUCTION: Breast cancer treatment includes many options depending on the tumor clinicopathological profile, which groups breast cancer into various subtypes. Bevacizumab is currently the only drug capable of targeting angiogenesis in breast cancer. Sorafenib has also been studied in combination with other agents. Areas covered: Pharmacological aspects of sorafenib, including results from preclinical studies on breast cancer cells; findings about clinical efficacy and safety in both single-arm and randomized clinical trials; ongoing trials. Expert opinion: Since sorafenib as a single agent has shown limited efficacy in breast cancer, its combination with other drugs is under investigation. Dose reduction is the main challenge when sorafenib is combined with chemotherapy or endocrine therapy. Although randomized phase-II trials on sorafenib plus chemotherapy versus chemotherapy alone have shown potential benefits in progression-free survival, preliminary results from a phase-III study in combination with capecitabine are negative. The definitive results of this trial and results from other ongoing phase-II trials will determine further developments of sorafenib in breast cancer. Although these additional data could help determine the most appropriate dose, drug combination and patient settings, a confirmation of the preliminary negative results reported in the phase-III trial are likely to discourage further use of sorafenib in breast cancer, given its non-negligible toxicity, lack of predicting markers, and the number of more promising drugs for breast cancer.

Cell-free DNA detected by "liquid biopsy" as a potential prognostic biomarker in early breast cancer.

As conventional biomarkers for defining breast cancer (BC) subtypes are not always capable of predicting prognosis, search for new biomarkers which can be easily detected by liquid biopsy is ongoing. It has long been known that cell-free DNA (CF-DNA) could be a promising diagnostic and prognostic marker in different tumor types, although its prognostic value in BC is yet to be confirmed. This retrospective study evaluated the prognostic role of CF-DNA quantity and integrity of HER2, MYC, BCAS1 and PI3KCA, which are frequently altered in BC. We collected 79 serum samples before surgery from women at first diagnosis of BC at Forlì Hospital (Italy) from 2002 to 2010. Twenty-one relapsed and 58 non-relapsed patients were matched by subtype and age. Blood samples were also collected from 10 healthy donors. All samples were analyzed by Real Time PCR for CF-DNA quantity and integrity of all oncogenes. Except for MYC, BC patients showed significantly higher median values of CF-DNA quantity (ng) than healthy controls, who had higher integrity and lower apoptotic index. A difference nearing statistical significance was observed for HER2 short CF-DNA (p = 0.078, AUC value: 0.6305). HER2 short CF-DNA showed an odds ratio of 1.39 for disease recurrence with p = 0.056 (95% CI 0.991-1.973). Our study suggests that CF-DNA detected as liquid biopsy could have great potential in clinical practice once demonstration of its clinical validity and utility has been provided by prospective studies with robust assays.

Progress with palbociclib in breast cancer: latest evidence and clinical considerations.

Deregulation of the cell cycle is a hallmark of cancer, and research on cell cycle control has allowed identification of potential targets for anticancer treatment. Palbociclib is a selective inhibitor of the cyclin-dependent kinases 4 and 6 (CDK4/6), which are involved, with their coregulatory partners cyclin D, in the G1-S transition. Inhibition of this step halts cell cycle progression in cells in which the involved pathway, including the retinoblastoma protein (Rb) and the E2F family of transcription factors, is functioning, although having been deregulated. Among breast cancers, those with functioning cyclin D-CDK4/6-Rb-E2F are mainly hormone-receptor (HR) positive, with some HER2-positive and rare triple-negative cases. Deregulation results from genetic or otherwise occurring hyperactivation of molecules subtending cell cycle progression, or inactivation of cell cycle inhibitors. Based on results of randomized clinical trials, palbociclib was granted accelerated approval by the US Food and Drug Administration (FDA) for use in combination with letrozole as initial endocrine-based therapy for metastatic disease in postmenopausal women with HR-positive, HER2-negative breast cancer, and was approved for use in combination with fulvestrant in women with HR-positive, HER2-negative advanced breast cancer with disease progression following endocrine therapy. This review provides an update of the available knowledge on the cell cycle and its regulation, on the alterations in cyclin D-CDK4/6-Rb-E2F axis in breast cancer and their roles in endocrine resistance, on the preclinical activity of CDK4/6 inhibitors in breast cancer, both as monotherapy and as partners of combinatorial synergic treatments, and on the clinical development of palbociclib in breast cancer.

Eribulin in Male Patients With Breast Cancer: The First Report of Clinical Outcomes.

BACKGROUND: Evidence on the management and treatment of male breast cancer is scant. We report the analysis of a multicenter Italian series of patients with male breast cancer treated with eribulin. To our knowledge, this is the first report on the use or eribulin in this setting. PATIENTS AND METHODS: Patients were retrospectively identified in 19 reference centers. All patients received eribulin treatment, according to the standard practice of each center. Data on the identified patients were collected using a standardized form and were then centrally reviewed by two experienced oncologists. RESULTS: A total of 23 patients (median age, 64 years; range, 42-80) were considered. The median age at the time of diagnosis of breast cancer was 57 years (range, 42-74). HER2 status was negative in 14 patients (61%), and 2 patients (9%) had triple-negative disease. The most common metastatic sites were the lung (n = 14; 61%) and bone (n = 13; 56%). Eribulin was administered for a median of 6 cycles (range, 3-15). All patients reported at least stable disease; two complete responses (9%) were documented. Eribulin was well-tolerated, with only four patients (17%) reporting grade 3 adverse events and two (9%) with treatment interruptions because of toxicity. Eight subjects (35%) did not report any adverse event during treatment. For patients with a reported fatal event, the median overall survival from the diagnosis of metastatic disease was 65 months (range, 22-228). CONCLUSION: Although hampered by all the limitations of any retrospective case series, the results of the present study suggest, for the first time, the use of eribulin as therapy for male breast cancer. IMPLICATIONS FOR PRACTICE: Evidence on the management and treatment of male breast cancer is eagerly awaited. Although hampered by all the limitations of any retrospective case series, the results of the present study suggest, for the first time, the use of eribulin as therapy for male breast cancer.

Androgen receptor signaling pathways as a target for breast cancer treatment.

The androgen receptor (AR) is a ligand-dependent transcription factor, and its effects on breast range from physiological pubertal development and age-related modifications to cancer onset and proliferation. The prevalence of AR in early breast cancer is around 60%, and AR is more frequently expressed in ER-positive than in ER-negative tumors. We offer an overview of AR signaling pathways in different breast cancer subtypes, providing evidence that its oncogenic role is likely to be different in distinct biological and clinical scenarios. In particular, in ER-positive breast cancer, AR signaling often antagonizes the growth stimulatory effect of ER signaling; in triple-negative breast cancer (TNBC), AR seems to drive tumor progression (at least in luminal AR subtype of TNBC with a gene expression profile mimicking luminal subtypes despite being negative to ER and enriched in AR expression); in HER2-positive breast cancer, in the absence of ER expression, AR signaling has a proliferative role. These data represent the rationale for AR-targeting treatment as a potentially new target therapy in breast cancer subset using androgen agonists in some AR-positive/ER-positive tumors, AR antagonists in triple-negative/AR-positive tumors and in combination with anti-HER2 agents or with other signaling pathways inhibitors (including PI3K/MYC/ERK) in HER2-positive/AR-positive tumors. Only the ongoing and future prospective clinical trials will allow us to establish which agents are the best option in every specific condition, keeping in mind that there is evidence of opposite androgens and AR agonist/antagonist drug effects on cell proliferation particularly in AR-positive/ER-positive tumors.

Pharmacokinetics, pharmacodynamics and clinical efficacy of pertuzumab in breast cancer therapy.

INTRODUCTION: Pertuzumab is a recombinant, humanized monoclonal antibody that binds to the dimerization domain of human epidermal growth factor receptor 2 (HER2), inhibiting the heterodimerization of HER2 with other HER receptors. It has shown synergy with trastuzumab in preclinical studies, and has led to a significant prolongation of progression-free and overall survival compared with placebo when added to trastuzumab and docetaxel for the first-line treatment of HER2-positive metastatic breast cancer (BC). AREAS COVERED: The HER family of receptors and their pathways, pertuzumab pharmacodynamics and preclinical activity, results from the main clinical trials, new drug combinations being developed, and predictors of response are discussed. EXPERT OPINION: Pertuzumab represents an important anti-HER2 agent that differs from, but is synergistic with, trastuzumab. It is already a standard of care in the first-line treatment of HER2-positive metastatic BC, and studies are ongoing to define its role in the adjuvant setting. It is now imperative to identify which tumors need dual HER2 targeting and to study the activity of pertuzumab in combination with other HER-targeted agents, including anti-HER1, -HER3 or -HER4, which could also prove useful in HER2-normal cancers. Potential competitors are anti-HER3 antibodies and bi- or tri-specific antibodies. Development in combination with phosphoinositide 3-kinase inhibitors or with anti PD-L1 is warranted.

Efficacy of endocrine therapy in relation to progesterone receptor and Ki67 expression in advanced breast cancer.

We assessed whether progesterone receptor (PgR) and Ki67 in primary tumors and/or matched metastases are predictors of clinical benefit from first-line endocrine therapy (ET) in advanced breast cancer. We evaluated patients treated at our institute with first-line ET (2002-2011), excluding those receiving concomitant chemotherapy or trastuzumab or pretreated with >2 lines of chemotherapy. A cut-off of 20 % immunostained cells was used for PgR and Ki67. The main endpoint was time-to-progression (TTP). Groups were compared by the log-rank test and Cox multivariate analysis. In the 135 assessable patients (93 % were receiving an aromatase inhibitor; biomarker assessment had been performed on primary tumors in 77 cases, on metastases in 23 and on both in 35), median TTP was 16 months (median follow-up 43 months). The overall discordance rate between primary tumors and metastases was 23 % for Ki67 and 31 % for PgR. A longer median TTP (24 vs. 12 months, P = 0.012) was seen for PgR >20 % in metastases. Ki67 showed a trend for TTP prediction in the entire case series (P = 0.062). Patients with high Ki67 and low PgR in metastases had a median TTP of only 5 months. High Ki67 in primary tumors (P = 0.026) or metastases (P = 0.01) predicted disease progression at the first evaluation. PgR in metastases remained a significant independent predictor of TTP at multivariate analysis (HR 2.45). In an ER-high population, PgR >20 % in metastases identified patients with a long TTP on endocrine treatment, while Ki67 >20 % was associated with an increased risk of non-response.