Background: Adherence to oral anticancer therapies among breast cancer patients is an often-overlooked issue. A lack of patient compliance can be caused by several factors, and may hinder the efficacy of prescribed medication, leading to a shorter than expected survival. In this context, few data about adherence to CDK4/6 inhibitors in real-world practice are available. We report here the results of a retrospective analysis of adherence to abemaciclib plus endocrine therapy in a cohort of women with hormone receptor-positive (HR+), epidermal growth factor 2 negative (HER2−) breast cancer. Methods: Abemaciclib adherence was computed as the ratio between the total number of cycles/months that medication was supplied and the months between the first and the last prescription. The proportion of Days Covered (PDC) ranged from 0 to 1. A score of 0.8 (i.e., 80% adherence rate) was the cutoff used to classify the patients as adherent (0.8 ≤ PDC ≤ 1) or non-adherent (0 ≤ PDC < 0.8). The received dose intensity was also calculated. Results: The abemaciclib pharmacy claims of 100 women with HR+/HER2− breast cancer were retrieved. Most patients (91%) were treated in the advanced setting. Abemaciclib was more frequently taken with an aromatase inhibitor (63%) than with fulvestrant (27%). In this population, the adherence rate was high (92.25% + 1.939 SD). The proportion of non-adherent patients taking abemaciclib with PDC <0.8 was 12%. There was a significative correlation between the occurrence of side effects and the use of <5 drugs for non-oncological illnesses, probably reflecting concomitant non-oncological diseases. Conclusions: Adherence to abemaciclib-based therapy is high in a real-life setting, pending the adequate and proactive management of patients. The careful evaluation of patients and detailed information about expected adverse events are essential to ensure adherence to this antineoplastic agent.

Background: Adherence to oral anticancer therapies among breast cancer patients is an often-overlooked issue. Lack of patients’ compliance can be caused by several factors, and may hinder the efficacy of prescribed medication, determining shorter than expected survival. In this context, few data are available about adherence to CDK4/6 inhibitors in the real-world practice. We report here the results of a retrospective analysis of adherence to abemaciclib plus endocrine therapy in cohort of women with hormone receptor-positive (HR+), epidermal growth factor 2 negative (HER2-) breast cancer. Methods: Abemaciclib adherence was computed as the ratio between the total number of cycles/months of supply for medication and months between the first and the last prescription. The proportion of Days Covered (PDC) may range from 0 to 1. A score of 0.8 (i.e. 80% adherence rate) was the cutoff to classify the patients as adherent (0.8 ≤ PDC ≤1) or non-adherent (0 ≤ PDC <0.8). Received dose intensity was also calculated. Results: Abemaciclib pharmacy claims of 100 women with HR+/HER2- breast cancer were retrieved. Most patients (91%) were treated in the advanced setting. Abemaciclib were more frequently taken with an aromatase inhibitor (63%), than with fulvestrant (27%). In this population, adherence rate was high (92.25% + 1.939 SD). The proportion of non-adherent patients taking abemaciclib with PDC <0.8 was 12%. There was a significative correlation between the occurrence of side effects and polypharmacy, probably reflecting concomitant non-oncological diseases. Conclusions: Adherence to abemaciclib-based therapy is high in a real-life setting, pending adequate and proactive management of patients. Careful patients’ evaluation and detailed information about expected adverse events are essential to ensure adherence to this antineoplastic agent.

Background: Older women represent a significant and increasing population of patients with breast cancer, accounting for over 40% of new cases of breast cancer. However, this growing subgroup of patients is still underrepresented in clinical trials, and treatment is usually selected based on limited data from retrospective subgroup analyses. However, the ESMO guidelines for metastatic breast cancer (mBC) suggest that the management decision should not be based on age alone. Nab-paclitaxel (nab-P) was associated with improved efficacy and a better safety profile than solvent-based taxanes without steroid or antihistamine premedication, making this treatment appealing to elderly patients. Patients and methods: This is an observational, retrospective, multicenter study, evaluating the safety and activity of nab-paclitaxel (nab-P) in elderly patients (≥65 years old) with HER2-negative mBC from 11 Sicilian oncology centers. The primary endpoint of the study was the safety nab-P in elderly mBC patients; secondary endpoints included the overall response rate (ORR), progression-free survival (PFS), and overall survival (OS). Results: We included 70 patients, and all were evaluable for safety and efficacy. All patients had previously been pretreated with taxane-based chemotherapy in a (neo)-adjuvant or metastatic setting. One third of the patients received nab-P as a fourth line therapy. Most of the patients were treated with nab-P at doses of 260 mg/m² 3-weekly (87.1%), and 12.9% received a nab-P dose of 125 mg/m² weekly. Patients’ characteristics included a median age of 67 years (range 65–83 years), a median ECOG PS of 1 (range 0–2), and the following intrinsic molecular subtypes: Luminal A (18.8%), Luminal B HER-2 negative (62.5%), and triple negative (18.8%). Nab-P was administered for a median of six cycles (range 1–21), with 35.5% of patients experiencing a dose reduction, and 11.5% treatment discontinuation due to toxicity. Adverse events were mainly G2-G3 and occurred mostly in patients treated with 3-weekly nab-P (85.7%). The ORR was 31.3% (CR in 6.3% and PR in 25% of pts) and the DCR was 70.4%. Median PFS was 6 months (95% CI, 2–38), and median OS was 40.5 months (95% CI, 7–255). Conclusions: Our real-life study showed that nab-P is an effective, well-tolerated regimen in elderly mBC patients, including taxane-pretreated patients, and can be safely administered in elderly mBC patients.

Hormone receptor-positive (HR+)/human epidermal growth factor receptor 2-negative (HER2−) breast cancer is the most prevalent subtype. Positron emission tomography (PET) imaging with 16α-18F-fluoro-17β-fluoroestradiol (¹⁸F-FES), a radiolabeled form of estradiol, enables the assessment in vivo of ER expression, ER heterogeneity in metastatic sites and functionally active ER capable of ligand binding. This imaging modality has been recently approved as a diagnostic tool for detecting ER-positive lesions in patients with recurrent or metastatic breast cancer. Despite promising activity, the role of this powerful tool is still debated. Herein we critically analyzed current evidence supporting the use of 18F-FES PET in metastatic ER+/HER2− breast cancer, highlighting the potential challenges for clinical implementation.

The Trop-2-directed antibody-drug conjugate sacituzumab govitecan (SG) has shown significant benefit in metastatic triple-negative breast cancer (mTNBC) in clinical trials. However, evidence about its effectiveness and safety in real-world heterogeneous patient populations is limited. This multicenter study, including the largest European and second-largest worldwide real-world cohort of SG-treated patients with mTNBC, offers valuable insights for its use in routine clinical practice. This analysis included 256 women with mTNBC treated with SG across 17 Italian oncology centers, consisting of 217 retrospectively identified patients and 39 prospectively enrolled patients. Treatment activity and safety were assessed according to RECIST v1.1 and Common Terminology Criteria for Adverse Events del National Cancer Institute (NCI-CTCAE) v5.0 criteria. Median patient age was 54 years (range 26-80), and 70.7% had TNBC at initial diagnosis. The median interval from metastatic diagnosis to SG initiation was 16 months (range 0-115), with a median of two prior treatment lines (range 0-7). Frequent metastatic sites were lymph nodes (60.9%), bone (43.0%), lung (42.6%), liver (33.2%), and brain (26.2%). Overall, 37.5% achieved complete or partial response, 27.7% had stable disease, and 31.2% experienced progression. At a median follow-up of 17.4 months, 202 patients had progressed, and 139 had died. Median real-world progression-free survival was 6.4 months [95% confidence interval (CI) 5.3-7.3] and median real-world overall survival was 13.6 months (95% CI 11.5-15.5). The most common treatment-related adverse events were alopecia (69.1%), neutropenia (57.0%), nausea (49.6%), anemia (46.9%), and diarrhea (36.7%). Grade 3-4 neutropenia occurred in 18.0% and 5.9%, respectively. Dose reductions were required in 36.5%, and 2.7% discontinued treatment. SG demonstrated durable clinical benefit and manageable toxicity in patients with mTNBC, highlighting the importance of optimized adverse-event management. The size and heterogeneity of the study population, including the largest reported cohort of patients with central nervous system metastases, support the robustness of these findings.