56P The impact of tumour detection method on genomic and clinical risk and chemotherapy recommendation in early hormone receptor positive breast cancer

Abstract

Symptomatic breast cancers share aggressive clinico-pathological characteristics compared to screen-detected breast cancers. The decision to administer adjuvant chemotherapy for early hormone receptor positive (HR+) HER-2 negative (HER2-) breast cancer patients, is guided by both the genomic and the clinical risk of disease recurrence. We assessed the association between the method of cancer detection and genomic and clinical risk, and its effect on adjuvant chemotherapy recommendation. Patients with early HR+ HER2- breast cancer, and known OncotypeDX Breast Recurrence Score (RS) test were included. A natural language processing (NLP) algorithm was used to identify the method of cancer detection. The clinical and genomic risks of symptomatic and screen-detected tumors were compared. The NLP algorithm identified the method of detection of 401 patients, with 216 (54%) diagnosed by routine screening, and the remainder secondary to symptoms. The distribution of OncotypeDX RS varied between the groups. In the symptomatic group there were lower proportions of low RS (13 vs 23%) and higher proportions of high RS (24 vs. 13%) compared to the screen-detected group (p=.03). Symptomatic tumors were significantly more likely to have a high clinical risk (59 vs 40%; p<.0001). Based on genomic and clinical risk and current guidelines, we found that women aged 50 and under, with symptomatic cancer, had an increased probability of receiving adjuvant chemotherapy recommendation compared to women with screen-detected cancers (57 vs. 35%; p=.03). We demonstrated an association between the method of cancer detection and both genomic and clinical risk. Symptomatic breast cancer, especially in young women, remains a poor prognostic factor that should be taken into account when evaluating patient prognosis and determining adjuvant treatment plans.