Abstract ES2-2: Treatment of early stage breast cancer in older adults
Authors: Wildiers H 
Published: March 2017

Abstract
About 30% of new breast cancer diagnoses occur in patients ≥70y. Tumor biology is generally slightly more favorable but all subtypes are seen in the older population.
Older breast cancer patients receive much less therapy compared to their younger counterparts, and undertreatment has been shown to lead to higher breast cancer relapse and breast cancer mortality. On the other hand, a sizeable proportion of older individuals with operable breast cancer die of non-cancer related causes, and the absolute benefit of adjuvant therapy decreases with increasing age, so overtreatment should also be avoided.
Therapy choice depends on tumor biology and tumor extent like in younger patients, but for the older population, there is also a major impact of patient preference, and general health status (life expectancy independent of the cancer).
In operable tumors, breast surgery is generally preferred since it decreases the risk of local relapse significantly, but it can be delayed for specific reasons.
Axillary staging decreases with age. Two randomized studies showed slightly more axillary recurrence (but still very low absolute risk) by omitting axillary lymph node dissection in patients without clinical nodal involvement, while there was no overall survival benefit. Avoidance of axillary surgery might be considered depending on the situation.
Adjuvant therapy decisions are particularly challenging since benefit for the individual patient cannot be measured immediately, and the decision process is actually a risk calculation.
Local relapse significantly decreases by addition of breast radiotherapy after breast conserving surgery, but the absolute benefit of breast irradiation decreases with age. Two randomized studies (CALGB9343 and PRIME II) showed that in older patients with small node negative hormone sensitive tumors, there is a significant but small decrease in local relapse by adding radiotherapy while no survival benefit is seen. The majority of this population will thus not derive relevant benefit from radiotherapy. The optimal indication for partial breast radiotherapy in older individuals is under investigation.
Adjuvant antihormonal therapy has similar survival benefit in young and old women with early breast cancer, but side effects may be more of an issue in the older population, and compliance has been shown to be worse with increasing age.
The decision to treat with adjuvant chemotherapy should not be based on chronological age alone, but rather on general tumor characteristics (biology and extent), general health status (life expectancy and risk of toxicity) and personal preference. Fit older patients with node-positive, hormone-negative disease potentially derive the largest benefit. Increasing age is associated with clearly higher risk of chemotherapy toxicity, but several recent studies have evaluated different chemotherapy regimens that may be suitable for older cancer patients.
Citation Format: Wildiers H. Treatment of early stage breast cancer in older adults [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr ES2-2.