Adjuvant Chemotherapy for Older Adults with Breast Cancer: Making the Standard a Standard

Aggressive Intrinsic Subtypes in Breast Cancer: A Predictor of Guideline Adherence in Older Patients With Breast Cancer?

BACKGROUND

Treatment side effects, comorbidities, and guideline-adherent treatment (GL+) influence the oncologic outcome of older breast cancer patients (oBCP) (age ≥ 70 years). The focus of this analysis was to investigate the associations among tumor characteristics, guideline adherence, and outcome and to compare these associations between younger breast cancer patients (yBCP) (age 50-69 years) and oBCP.

METHODS

This is a retrospective multicenter cohort study with 17 participating certified breast cancer centers. The analysis of 10,897 patient records collected from 1992 to 2008 for GL+ and clinical outcome was performed. Tumor and patient characteristics and their associations with GL+ were compared between oBCP and yBCP.

RESULTS

Nonguideline-adherent treatment (GL-) was associated with higher tumor stages and comorbidities. This effect was stronger in the oBCP group (P < .001). GL+ was significantly more common in yBCP than in oBCP (P < .001). The oBCP had significantly higher tumor stages, including tumor size (P < .001), nodal status (P < .001), and positive hormone receptors (P = .001). Tumor grading was lower (P = .001), and HER2neu overexpression was less frequent (P = .003) in oBCP. Overall survival and disease-free survival are significantly impaired if GL- occurred in patients with breast cancer independently of age.

CONCLUSIONS

GL- is associated with decreased disease-free survival and overall survival in both age groups. GL+ decreases advanced tumor characteristics in all age groups but significantly more in oBCP. If patients received GL+, we were unable to detect a statistical significant difference in the survival parameters.

Tumor biology in older breast cancer patients--what is the impact on survival stratified for guideline adherence? A retrospective multi-centre cohort study of 5378 patients

PURPOSE

The tumor biology of older breast cancer patients (oBCP) is usually less aggressive, however applied adjuvant treatment is often less potent resulting in an impaired disease free survival and overall survival in this group. This study tries to answer the following questions for the biological subtypes of oBCP (70+ y):

METHODS

Between 1992 and 2008 the BRENDA ('BRENDA' = quality of BREast caNcer care unDer evidence-bAsed guidelines) study group recorded medical data of 17 participating certified breast cancer centers in Germany. We performed a retrospective multi-center database analysis of 5632 patient records. Guideline-adherent-treatment (GL+) of oBCP(n = 1918) was compared to GL+ of yBCP(n = 3714).

RESULTS

OBCP were more likely to have hormone receptor positive (HR+) and HER2neu negative (HER2-) breast cancer (77.5% vs 74.5%). The rate of GL- was significantly different (p < 0.001) between the age groups and the biological subgroups (yBCP vs oBCP: 21.8%vs38.8% (HR+/HER2-); 30.6%vs49.7% (HR+/HER2+); 23.6%vs69.5% (HR-/HER2+); 31.4%vs67.8% (TNBC)). The survival parameters for HR+/HER2- and TNBC were significantly worse in case of GL- regarding chemotherapy, and if applicable endocrine therapy. A similar association only existed in HR-/HER2+ tumors for GL- for radiotherapy and in HR+/HER2+ tumors for chemotherapy.

CONCLUSIONS

Beside the significantly different distribution of biological subtypes in the age groups there is an association between biological subtype, and GL+ influencing survival parameters in oBCP.