Role of postmastectomy radiation after neoadjuvant chemotherapy in stage II-III breast cancer.
Int J Radiat Oncol Biol Phys 2012;
83:494-503. [PMID:
22579377 DOI:
10.1016/j.ijrobp.2012.01.068]
[Citation(s) in RCA: 66] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2011] [Revised: 01/19/2012] [Accepted: 01/21/2012] [Indexed: 11/15/2022]
Abstract
PURPOSE
To identify a cohort of women treated with neoadjuvant chemotherapy and mastectomy for whom postmastectomy radiation therapy (PMRT) may be omitted according to the projected risk of local-regional failure (LRF).
METHODS AND MATERIALS
Seven breast cancer physicians from the University of California cancer centers created 14 hypothetical clinical case scenarios, identified, reviewed, and abstracted the available literature (MEDLINE and Cochrane databases), and formulated evidence tables with endpoints of LRF, disease-free survival, and overall survival. Using the American College of Radiology appropriateness criteria methodology, appropriateness ratings for postmastectomy radiation were assigned for each scenario. Finally, an overall summary risk assessment table was developed.
RESULTS
Of 24 sources identified, 23 were retrospective studies from single institutions. Consensus on the appropriateness rating, defined as 80% agreement in a category, was achieved for 86% of the cases. Distinct LRF risk categories emerged. Clinical stage II (T1-2N0-1) patients, aged >40 years, estrogen receptor-positive subtype, with pathologic complete response or 0-3 positive nodes without lymphovascular invasion or extracapsular extension, were identified as having ≤ 10% risk of LRF without radiation. Limited data support stage IIIA patients with pathologic complete response as being low risk.
CONCLUSIONS
In the absence of randomized trial results, existing data can be used to guide the use of PMRT in the neoadjuvant chemotherapy setting. Using available studies to inform appropriateness ratings for clinical scenarios, we found a high concordance of treatment recommendations for PMRT and were able to identify a cohort of women with a low risk of LRF without radiation. These low-risk patients will form the basis for future planned studies within the University of California Athena Breast Health Network.
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