Long-Term Outcomes With Pharmacological Ovarian Suppression During Chemotherapy in Premenopausal Early Breast Cancer Patients.

BACKGROUND: Although use of gonadotropin-releasing hormone agonist (GnRHa) during chemotherapy is an established strategy to protect ovarian function in premenopausal breast cancer patients, no long-term safety data are available, raising some concerns in women with hormone receptor-positive disease. There are controversial data on its fertility preservation potential. METHODS: The Prevention of Menopause Induced by Chemotherapy: a Study in Early Breast Cancer Patients-Gruppo Italiano Mammella 6 (PROMISE-GIM6) trial is a multicenter, randomized, open-label, phase III superiority trial conducted at 16 Italian centers from October 2003 to January 2008. Eligible patients were randomly assigned to (neo)adjuvant chemotherapy alone (control arm) or combined with the GnRHa triptorelin (GnRHa arm). The primary planned endpoint was incidence of chemotherapy-induced premature ovarian insufficiency. Post hoc endpoints were disease-free survival (DFS), overall survival (OS), and post-treatment pregnancies. Hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated. RESULTS: Of 281 randomly assigned patients, 80.4% had hormone receptor-positive breast cancer. Median follow-up was 12.4 years (interquartile range = 11.3-13.2 years). No differences in 12-year DFS (65.7% [95% CI = 57.0% to 73.1%] in the GnRHa arm vs 69.2% [95% CI = 60.3% to 76.5%] in the control arm; HR = 1.16, 95% CI = 0.76 to 1.77) or in 12-year OS (81.2% [95% CI = 73.6% to 86.8%] in the GnRHa arm vs 81.3% [95% CI = 73.1% to 87.2%] in the control arm; HR = 1.17, 95% CI = 0.67 to 2.03) were observed. In patients with hormone receptor-positive disease, the hazard ratio was 1.02 (95% CI = 0.63 to 1.63) for DFS and 1.12 (95% CI = 0.59 to 2.11) for OS. In the GnRHa and control arms, 9 and 4 patients had a posttreatment pregnancy, respectively (HR = 2.14, 95% CI = 0.66 to 6.92). CONCLUSIONS: Final analysis of the PROMISE-GIM6 trial provides reassuring results on the safety of GnRHa use during chemotherapy as a strategy to preserve ovarian function in premenopausal patients with early breast cancer, including those with hormone receptor-positive disease.

Immunohistochemistry for Thymidine Kinase-1 (TK1): A Potential Tool for the Prognostic Stratification of Breast Cancer Patients.

Breast cancer (BC) is the most frequent non-cutaneous malignancy in women. Histological grade, expression of estrogen and progesterone receptors (ER and PgR), overexpression/amplification of the human epidermal growth factor receptor 2 (HER2) oncogene, and proliferative activity measured with ki-67 provide important information on the biological features of BC and guide treatment choices. However, a biomarker that allows a more accurate prognostic stratification is still lacking. Thymidine kinase-1 (TK1), a ubiquitous enzyme involved in the pyrimidine nucleotide recovery pathway, is a cell-proliferation marker with potential prognostic and predictive impacts in BC. Eighty (80) cases of invasive BC with a long-term follow-up were retrospectively selected, and clinicopathological data were collected for each patient. TK1 tissue expression was evaluated immunohistochemically. Data suggested that TK1 expression levels are positively correlated with ER and PgR expression, and negatively correlated with HER2 status and the impact on patients' distant recurrence-free survival (DRFS): in detail, among patients undergoing adjuvant chemotherapy, lower TK1 levels are correlated with better DRFS. Therefore, these results contribute to furthering the knowledge of TK1, suggesting a possible and important role of this enzyme as a biomarker in the stratification of BC patients.

PI3K mutations detected in liquid biopsy are associated to reduced sensitivity to CDK4/6 inhibitors in metastatic breast cancer patients.

BACKGROUND: PI3K pathway hyperactivation due to PIK3CA mutations contributes to endocrine resistance, and PIK3CA is one of the most frequently mutated genes in breast cancer (BC), occurring approximately 40 % of HR+, HER2- advanced BC (ABC). Cyclin-dependent kinase 4 and 6 inhibitors (CDK4/6i) have changed the treatment landscape of HR+, HER2- ABC. Putative mechanisms of resistance to CDK4/6i have been identified, but limited data are available on PI3K deregulation. The present study evaluates the impact of PIK3CA mutations on CDK4/6i plus hormone therapy and evaluates potential characteristics that may suggest for a PI3K screening in patients with ABC. METHODS: ABC patients were enrolled, and 12 mL of blood were collected in EDTA tubes at baseline prior to CDK4/6i plus hormone therapy. Plasma was separated and circulating free DNA (cfDNA) was extracted. PIK3CA mutation analysis was performed on a ddPCR. Selected and analyzed mutations included: p.C420R, p.E542 K, p.E545A, p.E545D, p.E545G, p.E545K, p.Q546E, p.Q546R, p.H1047L, p.H1047R, p.H1047Y. Statistical analysis were performed to investigate the predictive power of such mutations and any association with clinical factors. RESULTS: Thirty patients were enrolled. PIK3CA mutation status at baseline was independently associated with shorter median PFS (7.44 vs 12.9 months, p = 0.01) in subject receiving CDK4/6i plus hormone therapy. PIK3CA mutations were found to be associated to Ki67 expression in primary lesions (p = 0.006). Moreover, the probability to find a PI3K mutation improved considering also the therapeutic management in previous lines of treatment (McFadden's R2 = 0.415, p = 0.004; AUC of the ROC curve = 0.914). CONCLUSION: The findings of this pilot study suggest that the presence of a PI3K mutation in liquid biopsy correlates with a worse PFS in patients with ABC receiving CDK4/6i, and that liquid biopsy is a useful tool to suggests a better tailored pharmacological intervention.