# Tumor biology, treatment patterns, and recurrence in breast cancer patients aged 70–79 vs ≥ 80 years: a large-scale registry analysis

## TL;DR

This study compares breast cancer tumor biology and treatment outcomes in women aged 70–79 versus those aged 80 and older, highlighting the need for age-specific treatment approaches.

## Contribution

The study provides insights into age-related differences in tumor characteristics, treatment patterns, and metastasis rates in elderly breast cancer patients.

## Key findings

- Patients aged ≥80 had larger tumors and more mastectomies, with less systemic or axillary treatment.
- Patients ≥80 had higher rates of distant metastasis compared to those aged 70–79 across all biological subtypes.
- Endocrine therapy increased over time, while chemotherapy use peaked in 2009 and declined afterward.

## Abstract

With increasing life expectancy, breast cancer (BC) in elderly women is rising, yet patients over 80 remain underrepresented in clinical trials. Understanding differences in the age groups is essential to avoid over- and undertreatment. This analysis investigates age-specific tumor characteristics, treatment patterns and outcomes in women aged 70–79 versus ≥ 80 years.

This population-based analysis included BC patients treated at LMU Breast Center and Munich Red Cross Hospital between 2004 and 2015. Clinical data of 2699 women aged 70–79 and those ≥ 80 were compared to assess differences in tumor biology, treatment approaches and time to metastasis.

Breast-conserving surgery rates remained stable over time, while sentinel lymph node biopsy use increased in both age groups. Patients aged ≥ 80 more frequently presented with larger tumors, underwent mastectomy, and received less systemic or axillary treatment, despite similarly high hormone-receptor positivity. Chemotherapy use peaked in 2009 and declined thereafter, whereas endocrine therapy (ET) increased steadily. Patients ≥ 80 received chemotherapy less often and more frequently ET alone. Across all biological subtypes, patients ≥ 80 were associated with higher rates of distant metastasis compared with those aged 70–79 years.

Clinical and biological differences between women aged 70–79 and those ≥ 80 underscore the need for age-adapted, individualized BC management. Treatment decisions should carefully balance expected benefit against comorbidity burden and functional status. Refining age-specific treatment strategies may help to improve outcomes and quality of life, although this analysis cannot determine the effects of specific strategies in this growing patient population.