Biomarkers in breast cancer : quantifying discordance with best practice when hormone receptor status is an extravagance

• Published in: SA journal of oncology Vol. 4; no. 1; pp. 1 - 8
• Main Authors: Mushonga, Melinda, Ndlovu, Ntokozo, Nyakabau, Anna M, Ndarukwa-Jambwa, Sandra, Kassam, Zahra, Kadzatsa, Webster, Liu, Zhihui (Amy), Wong, Rebecca K.S
• Format: Journal Article
• Language: English
• Published: Cape Town AOSIS 01-01-2020; African Online Scientific Information Systems (Pty) Ltd t/a AOSIS; AOSIS (Pty) Ltd
• Subjects: Age; Agreements; Analysis; Biomarkers; Breast cancer; Cancer diagnosis; Cancer therapies; Care and treatment; Chemotherapy; Clinical trials; Diagnosis; Discordance; Endocrine therapy; Epidermal growth factor; Ethics; Family medical history; Histology; Hormones; Limited resources; Medical prognosis; Metastasis; Oncology; Patients; Radiation therapy; Statistical analysis; sub-Saharan Africa; Treatment guidelines; Women's health; Zimbabwe
• ISSN: 2518-8704; 2518-8704
• DOI: 10.4102/sajo.v4i0.134

Background: In Zimbabwe, the hormone receptor status is not always available when patients with breast cancer are started on treatment.Aim: This study evaluated the discordance of treatment approach in such patients, with National Comprehensive Cancer Network (NCCN) guideline recommendations as the reference standard when these results are eventually available.Setting: Female patients who presented to the Parirenyatwa Central Hospital Radiotherapy and Oncology Centre with a histological diagnosis of breast cancer, managed between 1 January 2014 and 31 December 2016.Methods: Patients with breast cancer having unknown receptor status at diagnosis, and the hormone receptor status were subsequently available either clinically or the tissues were available for study-specific analysis, were eligible for the study. The level of agreement between treatments received and the NCCN recommendations if the receptor status was known was tested using Kappa statistic.Results: Patients in stage I-III received treatment that were in strong agreement with the use of chemotherapy, and endocrine treatments with agreement scores of 1 (95% CI 0.91-1) and 0.81 (95% CI 0.65-0.95), respectively; but moderate agreement with regard to the choice of chemotherapy regimen, with a score of 0.5 (95% CI 0.32-0.68). There was a median delay of 8 (range 3-27) months for the availability of receptor status. Of the 38 stage IV patients, 33 (87%) were recommended chemotherapy. Of the 38 patients, 25 (66%) had hormone driven disease. There was somewhat agreement for use of chemotherapy, choice of chemotherapy regimen and use of endocrine treatments as initial choice with agreement scores of 0.53 (95% CI 0.36,0.69), 0.18 (95% CI 0.07, 0.35) and 0.68 (95% CI 0.51,0.82) respectively.Conclusion: Treatment approaches were largely in agreement with the NCCN guidelines for patients in stage I-III. Discordance was noted in stage IV patients with under-utilisation of hormone therapy as the initial treatment when the receptor status was unknown.