Open AccessOmission of radiation therapy following breast conservation in older (≥70 years) women with T1‐2N0 triple‐negative breast cancer
Author(s) -
Haque Waqar,
Verma Vivek,
Hsiao KuanYin,
Hatch Sandra,
Arentz Candy,
Szeja Sean,
Schwartz Mary,
Niravath Polly,
Bonefas Elizabeth,
Miltenburg Darlene,
Brian Butler Edward,
Teh Bin S.
Publication year - 2019
Publication title -
the breast journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.533
H-Index - 72
eISSN - 1524-4741
pISSN - 1075-122X
DOI - 10.1111/tbj.13443
Subject(s) - medicine , breast cancer , oncology , proportional hazards model , adjuvant , logistic regression , radiation therapy , triple negative breast cancer , stage (stratigraphy) , breast conserving surgery , lymphovascular invasion , multivariate analysis , cancer , gynecology , mastectomy , metastasis , paleontology , biology
Background Although randomized data support omitting adjuvant radiotherapy (RT) following breast conservation for T1‐2N0 estrogen receptor positive breast cancer in ≥70‐year‐old women, there remains a knowledge gap regarding its omission for triple‐negative BC (TNBC). Methods and materials The National Cancer Database (NCDB) was queried for ≥70‐year‐old females with newly diagnosed T1‐2N0M0 TNBC treated with breast conservation. Multivariable logistic regression ascertained factors associated with adjuvant RT administration. Overall survival (OS) between patients treated with or without adjuvant RT was estimated using the Kaplan‐Meier method. Cox proportional hazards modeling determined variables associated with OS. Results Of 8526 patients, 6283 (74%) patients received adjuvant RT, and 2243 (26%) did not. RT was more frequently withheld in older patients, those with higher comorbidities, lower income, pT2 disease, following margin‐positive resection, receipt of chemotherapy, and at academic centers ( P < 0.05 for all). Median follow‐up was 38.0 months. Five‐year OS was greater in the adjuvant RT group (77.2% vs 55.3%, P < 0.001); these differences persisted when stratifying for age, T stage, and chemotherapy utilization ( P < 0.001 for all). Omission of RT was also independently associated with poorer OS on multivariate analysis ( P < 0.001). Conclusions This investigation, the largest known such study to date, observed that omission of adjuvant RT for elderly women with T1‐2N0 TNBC was associated with poorer OS; this was observed across a range of age groups, as well as following stratification by T stage and chemotherapy usage. Although these results do not imply causation, caution must be exercised when considering omission of adjuvant RT in node‐negative TNBC patients.