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Title: Is Biological Subtype Prognostic of Locoregional Recurrence Risk in Women With pT1-2N0 Breast Cancer Treated With Mastectomy?

Abstract

Purpose: To examine locoregional and distant recurrence (LRR and DR) in women with pT1-2N0 breast cancer according to approximated subtype and clinicopathologic characteristics. Methods and Materials: Two independent datasets were pooled and analyzed. The study participants were 1994 patients with pT1-2N0M0 breast cancer, treated with mastectomy without radiation therapy. The patients were classified into 1 of 5 subtypes: luminal A (ER+ or PR+/HER 2−/grade 1-2, n=1202); luminal B (ER+ or PR+/HER 2−/grade 3, n=294); luminal HER 2 (ER+ or PR+/HER 2+, n=221); HER 2 (ER−/PR−/HER 2+, n=105) and triple-negative breast cancer (TNBC) (ER−/PR−/HER 2−, n=172). Results: The median follow-up time was 4.3 years. The 5-year Kaplan-Meier (KM) LRR were 1.8% in luminal A, 3.1% in luminal B, 1.7% in luminal HER 2, 1.9% in HER 2, and 1.9% in TNBC cohorts (P=.81). The 5-year KM DR was highest among women with TNBC: 1.8% in luminal A, 5.0% in luminal B, 2.4% in luminal HER 2, 1.1% in HER 2, and 9.6% in TNBC cohorts (P<.001). Among 172 women with TNBC, the 5-year KM LRR were 1.3% with clear margins versus 12.5% with close or positive margins (P=.04). On multivariable analysis, factors that conferred higher LRR risk were tumors >2 cm,more » lobular histology, and close/positive surgical margins. Conclusions: The 5-year risk of LRR in our pT1-2N0 cohort treated with mastectomy was generally low, with no significant differences observed between approximated subtypes. Among the subtypes, TNBC conferred the highest risk of DR and an elevated risk of LRR in the presence of positive or close margins. Our data suggest that although subtype alone cannot be used as the sole criterion to offer postmastectomy radiation therapy, it may reasonably be considered in conjunction with other clinicopathologic factors including tumor size, histology, and margin status. Larger cohorts and longer follow-up times are needed to define which women with node-negative disease have high postmastectomy LRR risks in contemporary practice.« less

Authors:
 [1];  [2];  [3]; ; ;  [1]
  1. Department of Radiation Oncology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts (United States)
  2. Radiation Therapy Program, British Columbia Cancer Agency, Vancouver Island Centre, University of British Columbia, Victoria, BC (Canada)
  3. Breast Cancer Outcomes Unit, British Columbia Cancer Agency, Vancouver Island Centre, University of British Columbia, Victoria, BC (Canada)
Publication Date:
OSTI Identifier:
22283313
Resource Type:
Journal Article
Journal Name:
International Journal of Radiation Oncology, Biology and Physics
Additional Journal Information:
Journal Volume: 88; Journal Issue: 1; Other Information: Copyright (c) 2014 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0360-3016
Country of Publication:
United States
Language:
English
Subject:
62 RADIOLOGY AND NUCLEAR MEDICINE; HISTOLOGY; MAMMARY GLANDS; NEOPLASMS; PHENOBARBITAL; PROBABILISTIC ESTIMATION; RADIOTHERAPY; SURGERY; WOMEN

Citation Formats

Truong, Pauline T., E-mail: ptruong@bccancer.bc.ca, Breast Cancer Outcomes Unit, British Columbia Cancer Agency, Vancouver Island Centre, University of British Columbia, Victoria, BC, Sadek, Betro T., Lesperance, Maria F., Alexander, Cheryl S., Shenouda, Mina, Raad, Rita Abi, and Taghian, Alphonse G. Is Biological Subtype Prognostic of Locoregional Recurrence Risk in Women With pT1-2N0 Breast Cancer Treated With Mastectomy?. United States: N. p., 2014. Web. doi:10.1016/J.IJROBP.2013.09.024.
Truong, Pauline T., E-mail: ptruong@bccancer.bc.ca, Breast Cancer Outcomes Unit, British Columbia Cancer Agency, Vancouver Island Centre, University of British Columbia, Victoria, BC, Sadek, Betro T., Lesperance, Maria F., Alexander, Cheryl S., Shenouda, Mina, Raad, Rita Abi, & Taghian, Alphonse G. Is Biological Subtype Prognostic of Locoregional Recurrence Risk in Women With pT1-2N0 Breast Cancer Treated With Mastectomy?. United States. https://doi.org/10.1016/J.IJROBP.2013.09.024
Truong, Pauline T., E-mail: ptruong@bccancer.bc.ca, Breast Cancer Outcomes Unit, British Columbia Cancer Agency, Vancouver Island Centre, University of British Columbia, Victoria, BC, Sadek, Betro T., Lesperance, Maria F., Alexander, Cheryl S., Shenouda, Mina, Raad, Rita Abi, and Taghian, Alphonse G. 2014. "Is Biological Subtype Prognostic of Locoregional Recurrence Risk in Women With pT1-2N0 Breast Cancer Treated With Mastectomy?". United States. https://doi.org/10.1016/J.IJROBP.2013.09.024.
@article{osti_22283313,
title = {Is Biological Subtype Prognostic of Locoregional Recurrence Risk in Women With pT1-2N0 Breast Cancer Treated With Mastectomy?},
author = {Truong, Pauline T., E-mail: ptruong@bccancer.bc.ca and Breast Cancer Outcomes Unit, British Columbia Cancer Agency, Vancouver Island Centre, University of British Columbia, Victoria, BC and Sadek, Betro T. and Lesperance, Maria F. and Alexander, Cheryl S. and Shenouda, Mina and Raad, Rita Abi and Taghian, Alphonse G.},
abstractNote = {Purpose: To examine locoregional and distant recurrence (LRR and DR) in women with pT1-2N0 breast cancer according to approximated subtype and clinicopathologic characteristics. Methods and Materials: Two independent datasets were pooled and analyzed. The study participants were 1994 patients with pT1-2N0M0 breast cancer, treated with mastectomy without radiation therapy. The patients were classified into 1 of 5 subtypes: luminal A (ER+ or PR+/HER 2−/grade 1-2, n=1202); luminal B (ER+ or PR+/HER 2−/grade 3, n=294); luminal HER 2 (ER+ or PR+/HER 2+, n=221); HER 2 (ER−/PR−/HER 2+, n=105) and triple-negative breast cancer (TNBC) (ER−/PR−/HER 2−, n=172). Results: The median follow-up time was 4.3 years. The 5-year Kaplan-Meier (KM) LRR were 1.8% in luminal A, 3.1% in luminal B, 1.7% in luminal HER 2, 1.9% in HER 2, and 1.9% in TNBC cohorts (P=.81). The 5-year KM DR was highest among women with TNBC: 1.8% in luminal A, 5.0% in luminal B, 2.4% in luminal HER 2, 1.1% in HER 2, and 9.6% in TNBC cohorts (P<.001). Among 172 women with TNBC, the 5-year KM LRR were 1.3% with clear margins versus 12.5% with close or positive margins (P=.04). On multivariable analysis, factors that conferred higher LRR risk were tumors >2 cm, lobular histology, and close/positive surgical margins. Conclusions: The 5-year risk of LRR in our pT1-2N0 cohort treated with mastectomy was generally low, with no significant differences observed between approximated subtypes. Among the subtypes, TNBC conferred the highest risk of DR and an elevated risk of LRR in the presence of positive or close margins. Our data suggest that although subtype alone cannot be used as the sole criterion to offer postmastectomy radiation therapy, it may reasonably be considered in conjunction with other clinicopathologic factors including tumor size, histology, and margin status. Larger cohorts and longer follow-up times are needed to define which women with node-negative disease have high postmastectomy LRR risks in contemporary practice.},
doi = {10.1016/J.IJROBP.2013.09.024},
url = {https://www.osti.gov/biblio/22283313}, journal = {International Journal of Radiation Oncology, Biology and Physics},
issn = {0360-3016},
number = 1,
volume = 88,
place = {United States},
year = {Wed Jan 01 00:00:00 EST 2014},
month = {Wed Jan 01 00:00:00 EST 2014}
}