Utilization and Outcomes of Breast Brachytherapy in Younger Women.

Abstract

PURPOSE:

To directly compare (1) radiation treatment utilization patterns; (2) risks of subsequent mastectomy; and (3) costs of radiation treatment in patients treated with brachytherapy versus whole-breast irradiation (WBI), in a national, contemporary cohort of women with incident breast cancer, aged 64 years and younger.

METHODS AND MATERIALS:

Using MarketScan health care claims data, we identified 45,884 invasive breast cancer patients (aged 18-64 years), treated from 2003 to 2010 with lumpectomy, followed by brachytherapy (n = 3134) or whole-breast irradiation (n = 42,750). We stratified patients into risk groups according to age (Age < 50 vs Age ≥ 50) and endocrine therapy status (Endocrine- vs Endocrine+). "Endocrine+" patients filled an endocrine therapy prescription within 1 year after lumpectomy. Pathologic hormone receptor status was not available in this dataset. In brachytherapy versus WBI patients, utilization trends and 5-year subsequent mastectomy risks were compared. Stratified, adjusted subsequent mastectomy risks were calculated using proportional hazards regression.

RESULTS:

Brachytherapy utilization increased from 2003 to 2010: in patients Age < 50, from 0.6% to 4.9%; patients Age ≥ 50 from 2.2% to 11.3%; Endocrine- patients, 1.3% to 9.4%; Endocrine+ patients, 1.9% to 9.7%. Age influenced treatment selection more than endocrine status: 17% of brachytherapy patients were Age < 50 versus 32% of WBI patients (P < .001); whereas 41% of brachytherapy patients were Endocrine-versus 44% of WBI patients (P = .003). Highest absolute 5-year subsequent mastectomy risks occurred in Endocrine-/Age < 50 patients (24.4% after brachytherapy vs 9.0% after WBI (hazard ratio [HR] 2.18, 95% confidence interval [CI] 1.37-3.47); intermediate risks in Endocrine-/Age ≥ 50 patients (8.6% vs 4.9%; HR 1.76, 95% CI 1.26-2.46); and lowest risks in Endocrine+ patients of any age: Endocrine+/Age < 50 (5.5% vs 4.5%; HR 1.18, 95% CI 0.61-2.31); Endocrine+/Age ≥ 50 (4.2% vs 2.4%; HR 1.71, 95% CI 1.16-2.51).

CONCLUSION:

In this younger cohort, endocrine status was a valuable discriminatory factor predicting subsequent mastectomy risk after brachytherapy versus WBI and therefore may be useful for selecting appropriate younger brachytherapy candidates.

• Authors: Grace L Smith, Jinhai Huo, Sharon H Giordano, Kelly K Hunt, Thomas A Buchholz, Benjamin D Smith
• Journal: International journal of radiation oncology, biology, physics (Int J Radiat Oncol Biol Phys) Vol. 93 Issue 1 Pg. 91-101 (Sep 01 2015) ISSN: 1879-355X [Electronic] United States
• PMID: 26279027 (Publication Type: Comparative Study, Journal Article, Research Support, N.I.H., Extramural, Research Support, Non-U.S. Gov't)
• Copyright: Copyright © 2015 Elsevier Inc. All rights reserved.

Chemical References

• Antibodies, Monoclonal, Humanized
• Antineoplastic Agents
• Trastuzumab

Topics

• Adult
• Age Factors
• Analysis of Variance
• Antibodies, Monoclonal, Humanized (therapeutic use)
• Antineoplastic Agents (therapeutic use)
• Brachytherapy (economics, statistics & numerical data, trends)
• Breast Neoplasms (chemistry, radiotherapy, therapy)
• Combined Modality Therapy
• Female
• Health Care Costs
• Humans
• Mastectomy (statistics & numerical data, trends)
• Mastectomy, Segmental
• Middle Aged
• Patient Selection
• Radiotherapy, Intensity-Modulated (economics)
• Risk Assessment (methods)
• Time Factors
• Trastuzumab
• Treatment Outcome
• United States
• Young Adult