Anastrozole Dose Escalation for Optimal Estrogen Suppression in Postmenopausal Early-Stage Breast Cancer: A Prospective Trial.

PURPOSE: We previously reported that postmenopausal women with estrogen receptor-α-positive breast cancer receiving adjuvant anastrozole 1 mg/day (ANA1) with estrone (E1) ≥1.3 pg/mL and estradiol (E2) ≥0.5 pg/mL [inadequate estrogen suppression (IES)] had a threefold increased risk of a breast cancer event. The objective of this study was to determine if increasing anastrozole to 10 mg/day (ANA10) could result in adequate estrogen suppression (AES: E1 <1.3 pg/mL and/or E2 <0.5 pg/mL) among those with IES on ANA1. PATIENTS AND METHODS: Postmenopausal women with estrogen receptor-α-positive breast cancer planning to receive adjuvant ANA1 were eligible. E1 and E2 were assessed pre- and post-8 to 10 weeks of ANA1. Those with IES were switched to 8- to 10-week cycles of ANA10 followed by letrozole 2.5 mg/day. E1 and E2 were assessed after each cycle. Anastrozole concentrations were measured post-ANA1 and post-ANA10. Primary analyses included patients who documented taking at least 80% of the planned treatment (adherent cohort). RESULTS: In total, 132 (84.6%) of 156 eligible patients were ANA1 adherent. IES occurred in 40 (30.3%) adherent patients. Twenty-five (78.1%) of 32 patients who began ANA10 were adherent, and AES was achieved in 19 (76.0%; 90% confidence interval, 58.1%-89.0%) patients. Anastrozole concentrations post-ANA1 and post-ANA10 did not differ by estrogen suppression status among adherent patients. AES was maintained/attained in 21 (91.3%) of 23 letrozole-adherent patients. CONCLUSIONS: Approximately 30% of ANA1-adherent patients had IES. Among those who switched to ANA10 and were adherent, 76% had AES. Further studies are required to validate emerging data that ANA1 results in IES for some patients and to determine the clinical benefit of switching to ANA10 or an alternative aromatase inhibitor.

Development of oral oncolytic nonadherence estimator (ORACLE): A pretreatment nonadherence risk assessment for oral oncolytics.

INTRODUCTION: To date, there is no adherence estimator to identify risk of nonadherence prior to initiating oral oncolytics. METHODS: A workgroup was assembled through the National Community Oncology Dispensing Association and tasked with creating a tool to meet this need. Tool constructs were defined after a review of the literature identifying top barriers to adherence. A second literature search was conducted to identify questions targeting specific barriers from validated adherence questionnaires. Once a finalized draft was complete, the risk assessment tool was built into an electronic survey where a risk category can be automatically calculated for the patient. RESULTS: The six most impactful factors affecting compliance to oral oncolytics were identified as patient's confidence, health literacy, perception of treatment, quality of life, social support, and complexity of chemotherapy regimen. A six-item questionnaire was created with five patient-directed questions and one clinician-directed question. Examples and descriptions were provided for clinicians to consider when categorizing complexity of a regimen. The tool was designed for responses to each question to be indexed into categories through a 10-point system. Results will be stratified into low, moderate, or high risk for nonadherence. CONCLUSION: The creation of a tool to predict nonadherence prior to starting therapy is an unmet need for patients initiating oral oncolytics. The aim of this tool is to meet those needs and better guide clinicians to provide patients with strategies to better manage nonadherence. Next steps include tool validation and piloting in clinical practice.

Risk of relapse in patients receiving azithromycin after allogeneic HSCT.

Following publication of the ALLOZITHRO trial, the FDA released a safety announcement warning that azithromycin should not be given long-term to prevent BOS in patients with a blood or lymph cancer who have undergone allogeneic HSCT. Our site typically initiated azithromycin when patients were diagnosed with BOS post-transplant rather than empirically as prevention. The purpose of our study was to discern whether the use of azithromycin at the time of diagnosis of BOS increased risk of disease relapse in patients who received an allogeneic HSCT for malignant disease. We retrospectively reviewed 432 patients in 3 cohorts: Cohort (1) patients who received greater than or equal to 2 weeks of azithromycin therapy (n = 98); Cohort (2) patients who received azithromycin therapy for less than 2 weeks (n = 63); and Cohort (3) patients who never received azithromycin therapy (n = 271). Neither patients in Cohort 1 (HR 0.44; 95% CI, 0.12-1.53, P = 0.19) nor Cohort 2 (HR 0.66; 95% CI, 0.2-2.19, P = 0.49) were associated with an increased risk of relapse when compared to those who had never received azithromycin. Our data indicate that the prolonged use of azithromycin after allogeneic HSCT is not associated with an increased rate of hematologic relapse.

Pharmacogenomic diversity of tamoxifen metabolites and estrogen receptor genes in Hispanics and non-Hispanic whites with breast cancer.

Ethnic differences in patient genetics and breast cancer (BC) biology contribute to ethnic disparities in cancer presentation and patient outcome. We prospectively evaluated SNPs within phase I and phase II tamoxifen (TAM) metabolizing enzymes, and the estrogen receptor gene (ESR1), aiming to identify potential pharmacogenomic ethnicity patterns in an ER-positive BC cohort constituted of Hispanic and Non-Hispanic White (NHW) women in South Texas. Plasma concentrations of TAM/metabolites were measured using HPLC. CYP2C9, CYP2D6 and SULT1A1 genotypes were determined by DNA sequencing/Pyrosequencing technology. ESR1 PvuII and XbaI SNPs were genotyped using Applied Biosystems Taqman Allelic Discrimination Assay. Hispanics had higher levels of TAM, 4-hydroxytamoxifen, and endoxifen than NHWs. There was a higher prevalence of CYP2D6 EM within Hispanics than NHWs, which corresponded to higher endoxifen levels, but no differences were verified with regard to CYP2C9 and SULT1A1. We found a higher incidence of the wild type forms of the ESR1 in Hispanics than NHWs. The performance status, the disease stage at diagnosis, and the use of aromatase inhibitors might have overcome the overall favorable pharmacogenomics profile of Hispanics when compared to NHWs in relation to TAM therapy responsiveness. Our data strongly point to ethnical peculiarities related to pharmacogenomics and demographic features of TAM treated Hispanics and NHWs. In the era of pharmacogenomics and its ultimate goal of individualized, efficacious and safe therapy, cancer studies focused on the Hispanic population are warranted because this is the fastest growing major demographic group, and an understudied segment in the U.S.