114070-132

Time trends in the use of adjuvant chemotherapy (CTX) and outcomes in women with T1N0 breast cancer (BC) in the National Comprehensive Cancer Network (NCCN).

Subcategory: 
Category: 
Breast Cancer - Triple-Negative/Cytotoxics/Local Therapy
Session Type and Session Title: 
Oral Abstract Session, Breast Cancer - Triple-Negative/Cytotoxics/Local Therapy
Abstract Number: 
1006
Citation: 
J Clin Oncol 31, 2013 (suppl; abstr 1006)
Author(s): 
Ines Maria Vaz Duarte Luis, Rebecca A Ottesen, Melissa E Hughes, Rizvan Mamet, Harold J. Burstein, Stephen B. Edge, Ana M. Gonzalez-Angulo, Sara H. Javid, Beverly Moy, Hope S. Rugo, Richard L. Theriault, Jane C. Weeks, Nancy U. Lin; Dana-Farber Cancer Institute, Boston, MA; City of Hope, Duarte, CA; Roswell Park Cancer Institute, Buffalo, NY; The University of Texas MD Anderson Cancer Center, Houston, TX; University of Washington, Seattle, WA; Massachusetts General Hospital Cancer Center, Harvard Medical School, Boston, MA; University of California, San Francisco, San Francisco, CA

Abstracts that were granted an exception in accordance with ASCO's Conflict of Interest Policy are designated with a caret symbol (^).

Abstract Disclosures

Abstract: 

Background: The role of adjuvant CTX in women with small BC is controversial. Here we analyze time trends of CTX use and outcomes in women with T1N0 BC treated at NCCN cancer centers. Methods: 8917 women were identified who received surgery or systemic therapy at an NCCN center with T1a, T1b or T1c N0 M0 BC between 2000-09. Tumors were grouped by biologic subgroups by hormone receptor (HR) and HER2 status and T subgroups (T1a, T1b, T1c). Primary endpoints were receipt of adjuvant CTX (± trastuzumab) and BC specific survival (BCSS). Chi-square, Cochran Armitage trend, Kaplan Meier estimates, log-rank test and Cox hazard proportional regression were used for analysis. In this report we focus on T1a/b results (N=4113). Results: Median follow up time was 5.5 years (range, 0.7-12.7). CTX use differed according to biologic and T subgroups, with significant changes over time (Table). In 2009, more than 50% of patients (pts) with HER2+ and HR-2- T1a/b breast cancers received CTX (± trastuzumab). The table lists use of CTX by year and subset and the 5 year BCSS for pts treated and not treated with CTX. Conclusions: A high proportion of pts with HER2+ and HR-HER2- T1N0 breast cancers received adjuvant CTX, with a sharp increase in use of CTX among HER2+ over the past decade. Use of CTX is higher in T1b compared to T1a tumors. In this study, women with T1a and T1b tumors have an excellent prognosis without CTX at 5 Yr. Careful examination of cutoffs for absolute benefit sufficient to recommend CTX is warranted.

Year of
diagnosis
Percent of adjuvant CTX (± trastuzumab) (%)
HR+HER2-
(T1a, b, c)
N=6789
HR+HER2+
(T1a, b, c)
N=738
HR-HER2+
(T1a, b, c)
N=364
HR-HER2-
(T1a, b, c)
N=1026
T1a
N=984
T1b
N=2246
T1a
N=135
T1b
N=199
T1a
N=81
T1b
N=105
T1a
N=99
T1b
N=264
P<0.0001 P<0.0001 P=0.0003 P=0.3600
2003 3% 10% 13% 36% 50% 76% 18% 70%
2005 1% 11% 25% 50% 38% 77% 31% 50%
2009 2% 13% 47% 100% 56% 100% 50% 69%
5 Yr BCSS
CTX
(95 %CI)
100%*¥
98.8 %
(95.4-99.7)
100%*¥
100%*º
100%*¥
96.3%
(88.8-98.8)
100%*¥ 97.9%
(93.6-99.3)
No CTX
(95 %CI)
99.9%
(99.2-100)
99.4 %
(98.9-99.7)
98.5%
(89.9-99.8)
97.7%
(91.1-99.4)
94.9 %¥
(81-98.7)
100%*º¥ 95.4% (86.4-98.5) 95.2%
(87.6-98.2)

* No BC death as of 5 yr º 1 BC death occurred after 5 yr ¥n ≤50