Abstract P5-14-13: Benefits of Oncotype DX genomic screening in a geriatric vs. non-geriatric cohort. Analyzing key factors in therapy decision making process
Authors: Chiru Elena D , Kuhar Cvetka Grasic , Oseledchyk Anton , Kurzeder Christian , Vetter Marcus 
Published: March 2023

Abstract
Introduction In early luminal HER2 negative breast cancer Oncotype DX® Recurrence-Score (RS) has been broadly validated in pre- and postmenopausal patients and can predict prognosis and benefit of chemotherapy. Its value in elderly breast cancer populations has not been deeply addressed. This study analyses clinical and pathologic factors, RS distribution and outcomes in an elderly vs. non-elderly breast cancer population with the purpose of establishing RS added value to the therapy decision-making process in a geriatric cohort.
Methods This is a retrospective analysis of available data from patients with early luminal HER2 negative breast cancer treated at the University Hospital Basel and the Cantonal Hospital Baselland between 2010 and 2022. Cohort A (A) consists of patients &lt; 70 years old and cohort B (B) of patients aged ≥70 years. At moment of decision for adjuvant treatment all patients had known RS result.
Results A and B included 266 (81%) and 60 (19%) patients, respectively. The median age in A was 55.2 and in B, 74 years. The following clinical and pathologic factors were different in B vs. A: co-morbidities (55 % vs. 35%, p=0.005), BMI (BMI≥25 (overweight vs. normal, p=0.023), tumor size (31.3 mm vs 23.6 mm p=0.021). Geriatric patients also tended to have a clinically higher risk status (83% vs. 70%; p=0.05). There was a trend for a higher mastectomy rate in B vs. A (41.7% vs. 29%, p=0.065), significantly less radiotherapy use (65% vs. 81%, p=0.009) and more osteo-oncologic treatment (61% vs 43%, p=0.013). RS distribution was not significantly different between cohorts (A vs. B was: RS 1-15: 44.3% vs 41.7%, RS 16-25 41.2% vs 35% and RS≥26 14.5% vs 23.3%; p=0.234). Adjuvant chemotherapy was performed in 11.5% of B and 22.9% of A (p=0.116) and adjuvant endocrine therapy in 98.3% of B vs. 93.5% of A (p=p=0.214). Tumor board suggested systemic treatment was not implemented in 22% vs 15 %, (B vs. A; p =0.087). With a median follow-up of 36.6 months, recurrence rate was higher, but not statistically significant in B vs. A (10% vs 6%, p=0.259). Relapse rate was higher with RS≥26 vs. RS 0-25 (13.5% in B vs. 5.7% in A; p=0.043).
Conclusions Older breast cancer patients tend to have higher clinical risk status, more co-morbidities and higher BMI. RS distribution was not significantly different between the two cohorts, however higher RS did pose a higher relapse rate for older patients in our cohort. Although RS based guidelines, still apply in therapy decision making in the case of geriatric breast cancer patients, clinical practice points to a rather individualized treatment in which all clinical and pathological factors are weighted.

Citation Format: Elena D Chiru, Cvetka Grasic Kuhar, Anton Oseledchyk, Christian Kurzeder, Marcus Vetter. Benefits of Oncotype DX genomic screening in a geriatric vs. non-geriatric cohort. Analyzing key factors in therapy decision making process [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P5-14-13.