Efficacy of combined therapy of goserelin and letrozole on very young women with advanced breast cancer as first-line endocrine therapy

Real-world effectiveness of aromatase inhibitors and fulvestrant in HR+/HER2- advanced breast cancer: a snapshot of the last two years before conventional use of CDK 4/6 inhibitors in a Portuguese institution

Background

Monotherapy with aromatase inhibitors and fulvestrant were the standard-of-care for hormone receptor-positive (HR+)/human epidermal growth factor receptor-type2 negative (HER2-) advanced breast cancer, before integration of cyclin-dependent kinase 4/6 inhibitors. Effectiveness data is essential for regulatory action, but little is known about real-world use of aromatase inhibitors and fulvestrant.

Methods

A retrospective cohort study was conducted resorting to data from a cancer registry to identify adult women with HR+/HER- advanced breast cancer exposed to aromatase inhibitors or fulvestrant (31 May 2017-31 March 2019) at the main oncology hospital in Portugal. Cases were updated with follow-up until death or cut-off (31 March 2021) and pseudoanonymized data extracted. Primary outcome was overall survival (OS) and secondary time to treatment failure (TTF), estimated using survival analysis and compared with published trials.

Results

192 patients were distributed by subgroups according to the medicine. Letrozole: OS 30.8 (95% confidence interval (CI) 20.6-41.4); TTF 11.2 (95%CI 8.7-13.7). Exemestane: OS 22.1 (95%CI 9.7-34.6); TTF 6.0 (95%CI 4.1-7.8). Fulvestrant: OS 21.6 (95%CI 16.5-26.7); TTF 5.6 (95%CI 4.5-6.6).

Conclusions

Estimated effectiveness (OS) of letrozole and fulvestrant was, respectively, 3.2-3.5 months lower than reported. The clinical meaning seems uncertain and may be explained a higher proportion of worse prognostic characteristics in patients treated in the real-world.

Novel anti-PD-L1 peptide selected from combinatorial phage library inhibits tumor cell growth and restores T-cell activity

PD-L1 overexpression on tumour cells forms a protective shield against cytotoxic T-cell killing, which consequently leads to immune evasion. Engagement of PD-1 in tumour infiltrating T cells with PD-L1 results in an exhausted T-cell phenotype, thus preventing an effective immune response against tumour cells. In the present study, we employed phage display combinatorial peptide library to discover anti-PD-L1 peptides. The peptides discovered here, could computationally exhibit specific interactions with PD-L1 at residues with which PD-1 also interacts. Binding affinity and specificity of the peptides were examined by flow cytometry. Anti- tumour activity of peptides was also investigated using several cell-based assays. Surprisingly, we demonstrated that Pep-39 can inhibit PDL-1, and reduce MDA-MB-231, CT-26, and DU-145 cells survival. In co-culture experiments, Pep-39 restored proliferation of Jurkat cells cultured in the presence of MDA-MB-231 cells. In addition, Jurkat cells apoptosis was impeded, indicating blocking potential of Pep-39 against PD-1/PD-L1 interaction.

Targeted Therapy for Premenopausal Women with HR+, HER2- Advanced Breast Cancer: Focus on Special Considerations and Latest Advances

The incidence of advanced breast cancer in premenopausal women is increasing, and breast cancer in younger women is often more aggressive and has a worse prognosis compared with breast cancer in older women. Premenopausal women with hormone receptor-positive (HR⁺) breast cancer are frequently under-represented in clinical trials, and treatment strategies in the premenopausal setting are usually extrapolated from data from postmenopausal patients, with the addition of ovarian function suppression to endocrine therapy in HR⁺ disease. However, the underlying biology of breast cancer in premenopausal women can be different from postmenopausal women, and treatment strategies should ideally be specifically tested in premenopausal patients. Recent phase III trials have now investigated cyclin-dependent kinase 4/6 (CDK4/6) inhibitors in premenopausal patients with HR⁺, HER2^- advanced breast cancer: Palbociclib and abemaciclib have been tested in a subset of premenopausal patients in the PALOMA-3 and MONARCH-2 studies, and ribociclib has been tested in the phase III MONALEESA-7 trial, which was entirely dedicated to premenopausal women. This comprehensive review summarizes the differences in the biology of HR⁺, HER2^- breast cancer in the premenopausal population compared with the postmenopausal population; discusses special considerations for treatment of premenopausal women; and reviews the evidence from clinical trials investigating endocrine therapy, other targeted treatments, and ovarian function suppression in the HR⁺, HER2^- advanced breast cancer setting. Clin Cancer Res; 24(21); 5206-18. ©2018 AACR.

Aromatase inhibitors in premenopausal women with breast cancer: the state of the art and future prospects

Approximately 11% of patients with breast cancer (bca) are diagnosed before menopause, and because in most of those patients the tumour expresses a hormone receptor, treatment with endocrine interventions can be applied in any setting of disease (early or advanced). In the past, hormonal treatment consisted only of the estrogen receptor modulator tamoxifen, associated with luteinizing hormone-releasing hormone (lhrh); more recently, aromatase inhibitors (ais) have come into widespread use. The ais interfere with the last enzymatic step of estrogen synthesis in which androgens are converted into estrogens. Initially, the ais were used alone in postmenopausal patients to prevent disease recurrence, but together with lhrh analogs, they can be used in premenopausal patients to produce better estrogen suppression than can be achieved with tamoxifen plus a lhrh analog. Using a systematic review of the scientific literature (prospective and retrospective studies), we set out to assess the efficacy of ais compared with other endocrine therapy in various disease settings (neoadjuvant, adjuvant, metastatic).

Peptide Blocking of PD-1/PD-L1 Interaction for Cancer Immunotherapy

Immunotherapy has become a promising alternative therapeutic approach for cancer patients. Interruption of immune checkpoints, such as CTLA-4 and PD-1, has been verified to be a successful means for cancer therapy in clinical trials. mAb targeting PD-L1 has been approved to treat urothelial carcinoma, non-small cell lung cancer, or Merkel cell carcinoma by the FDA. However, the high cost of the antibody can limit its application. In our study, targeting PD-L1 peptide (TPP-1), which specifically binds to PD-L1 with high affinity, was identified through bacterial surface display methods. Using a T-cell activation assay and mixed lymphocyte reaction, TPP-1 was verified to interfere with the interaction of PD-1/PD-L1. To examine the inhibitory effect of TPP-1 on tumor growth in vivo, a xenograft mouse model using H460 cells was established. The growth rate of tumor masses in TPP-1 or PD-L1 antibody-treated mice was 56% or 71% lower than that in control peptide-treated mice, respectively, indicating that TPP-1 inhibits, or at least retards, tumor growth. IHC of the tumors showed that IFNγ and granzyme B expression increased in the TPP-1 or PD-L1 antibody-treated groups, indicating that TPP-1 attenuates the inhibitory effect of PD-L1 on T cells and that T cells may get reactivated. On the basis of our data, TPP-1 peptide could work as an alternative to antibodies for tumor immunotherapy. Cancer Immunol Res; 6(2); 178-88. ©2017 AACR.

The Role of Gonadotropin-Releasing-Hormone Analogues in the Treatment of Breast Cancer

The prognosis of premenopausal breast cancer patients with early disease has improved over the past decades, particularly in women expressing hormone receptors in their tumors. Tamoxifen, a selective estrogen receptor modulator, has dramatically changed outcomes in these patients and remains one of the standards of care. Ovarian function suppression by gonadotropin-releasing-hormone analogues (GnRHa) represents an additional treatment option. Long-term data are required before firm conclusions can be drawn, whereas recent clinical trials suggest that the use of GnRHa is effective in both adjuvant and metastatic settings, particularly in younger patients (<35 years old). The decision to select the optimal therapy should be individualized according to the biological characteristics of tumors, estimates of disease response, comorbidities, patient preference, and long-term toxicity.

New insights into endocrine therapy for young women with breast cancer

Managing estrogen receptor-positive breast cancer in young women (<40 years) requires a multidisciplinary/personalized approach, covering both clinical and psychosocial aspects. Five years of tamoxifen has been the standard adjuvant endocrine therapy for many years. Recent data from the adjuvant randomized trials TEXT-SOFT show that the aromatase inhibitor exemestane plus ovarian suppression significantly reduces recurrences as compared with tamoxifen plus ovarian suppression. The ATLAS and aTToM trials represent the first evidence of a beneficial effect of extended endocrine therapy with tamoxifen in premenopausal women. Outside of a clinical trial, no data support neoadjuvant endocrine therapy in young women. In the metastatic setting, tamoxifen or aromatase inhibitors, both with ovarian suppression/ablation, should be the preferred choice, unless rapid tumor shrinkage is needed. No data are available with fulvestrant in young patients.