The predictive impact of body mass index on the efficacy of extended adjuvant endocrine treatment with anastrozole in postmenopausal patients with breast cancer: an analysis of the randomised ABCSG-6a trial.

Abstract

BACKGROUND:

We investigated whether body mass index (BMI) can be used as a predictive parameter indicating patients who benefit from extended aromatase inhibitor (AI) treatment.

METHODS:

The ABCSG-6a trial re-randomised event-free postmenopausal hormone receptor-positive patients from the ABCSG-6 trial to receive either 3 additional years of endocrine therapy using anastrozole vs nil. In this retrospective analysis, we investigated the prognostic and predictive impact of BMI on disease outcome and safety.

RESULTS:

In all, 634 patients (177 normal weight, 307 overweight, and 150 obese) patients were included in this analysis. Normal weight patients with additional 3 years of anastrozole halved their risk of disease recurrence (disease-free survival (DFS) HR 0.48; P=0.02) and death (HR 0.45; P=0.06) and had only a fifth of the risk of distant metastases (HR 0.22; P=0.05) compared with normal weight patients without any further treatment. In contrast, overweight+obese patients derived no benefit from additional 3 years of anastrozole (DFS HR 0.93; P=0.68; distant recurrence-free survival HR 0.91; P=0.78; and OS HR 0.9; P=0.68). The possible predictive impact of BMI on extended endocrine treatment could be strengthened by a Cox regression interaction model between BMI and treatment (P=0.07).

CONCLUSION:

Body mass index may be used to predict outcome benefit of extended AI treatment in patients with receptor-positive breast cancer.

• Authors: M Gnant, G Pfeiler, H Stöger, B Mlineritsch, F Fitzal, M Balic, W Kwasny, M Seifert, M Stierer, P Dubsky, R Greil, G Steger, H Samonigg, C Fesl, R Jakesz
• Journal: British journal of cancer (Br J Cancer) Vol. 109 Issue 3 Pg. 589-96 (Aug 06 2013) ISSN: 1532-1827 [Electronic] England
• PMID: 23868011 (Publication Type: Journal Article, Multicenter Study, Randomized Controlled Trial)

Chemical References

• Antineoplastic Agents, Hormonal
• Aromatase Inhibitors
• Nitriles
• Triazoles
• Anastrozole

Topics

• Adolescent
• Adult
• Anastrozole
• Antineoplastic Agents, Hormonal (administration & dosage, adverse effects)
• Aromatase Inhibitors (administration & dosage, adverse effects)
• Body Mass Index
• Breast Neoplasms (drug therapy)
• Chemotherapy, Adjuvant
• Drug Administration Schedule
• Female
• Humans
• Middle Aged
• Neoplasms, Hormone-Dependent (drug therapy)
• Nitriles (administration & dosage, adverse effects)
• Obesity (physiopathology)
• Overweight (physiopathology)
• Postmenopause
• Retrospective Studies
• Triazoles (administration & dosage, adverse effects)
• Young Adult