Authors' objectives: Background Breast cancer is the most common cancer among women in Sweden, 8,000 being diagnosed annually. Both incidence and survival rates have increased over the years. According to clinical routine, patients with hormone sensitive (luminal) breast cancer are treated post-operatively with adjuvant endocrine therapy for 5-10 years. Patients that are hormone-receptor negative are instead most often treated with adjuvant chemotherapy, and patients that are HER2-positive receive both chemotherapy and HER2-directed therapies. There are also a high-risk group of patients with luminal breast cancer either with a higher grade or proliferation (Luminal B) or patients that are node-positive where adjuvant chemotherapy often are recommended. To improve the prediction of clinical outcomes and to identify breast cancer patients in this group for whom chemotherapy can be withheld, and thereby adverse effects associated with such treatment avoided, gene expression assays have been developed. Questions at issue 1. In breast cancer patients with luminal tumour and intermediate clinical risk of recurrence, how does the use of gene expression assays affect clinical outcomes and decisions to withhold adjuvant chemotherapy, compared with not using such molecular profiling? 2. In breast cancer patients with luminal tumour, intermediate clinical risk of recurrence, and low/intermediate genetic risk of recurrence according to a gene expression assay, will survival, healthrelated quality of life, and/or recurrence be affected if chemotherapy is withheld?

Authors' results and conclusions: This HTA on gene expression testing in patients with luminal breast cancer at intermediate clinical risk of recurrence reveals a lack of studies, comparing test versus no test, evaluating overall survival, health-related quality of life, and recurrence. The studies on chemotherapy decision making were performed in various settings where chemotherapeutic traditions may vary, and no general conclusions can be drawn whether the use of chemotherapy would decrease or increase by the use of such tests. After gene expression testing, withholding adjuvant chemotherapy, versus providing such treatment, probably results in similar overall survival rates over nine years, while a slightly increased risk of recurrence can probably not be excluded. The effects of avoiding adverse reactions from chemotherapy by withholding such treatment, has not been studied in the patient group at issue.

Project Status: Completed

Year Published: 2019

URL for published report: https://mellanarkiv-offentlig.vgregion.se/alfresco/s/archive/stream/public/v1/source/available/sofia/su4372-1728378332-345/native/2019_107%20HTA-rapport%20Gene%20expression%20profile%20BC.pdf

English language abstract: An English language summary is available

Publication Type: Full HTA

Organisation Name: The Regional Health Technology Assessment Centre

Contact Address: The Regional Health Technology Assessment Centre, Region Vastra Gotaland, HTA-centrum, Roda Straket 8, Sahlgrenska Universitetssjukhuset, 413 45 GOTHENBORG, Sweden

Contact Name: hta-centrum@vgregion.se

Contact Email: hta-centrum@vgregion.se