Abstract P3-07-01: Breast cancer-specific mortality (BCSM) in patients age 50 years or younger with node-positive (N+) breast cancer (BC) treated based on the 21-gene assay in clinical practice

Author(s):  
Valentina I Petkov ◽  
Allison W Kurian ◽  
Debbie M Jakubowski ◽  
Steven Shak
2016 ◽  
Vol 2 (1) ◽  
Author(s):  
Valentina I Petkov ◽  
Dave P Miller ◽  
Nadia Howlader ◽  
Nathan Gliner ◽  
Will Howe ◽  
...  

Abstract The 21-gene Recurrence Score assay is validated to predict recurrence risk and chemotherapy benefit in hormone-receptor-positive (HR+) invasive breast cancer. To determine prospective breast-cancer-specific mortality (BCSM) outcomes by baseline Recurrence Score results and clinical covariates, the National Cancer Institute collaborated with Genomic Health and 14 population-based registries in the the Surveillance, Epidemiology, and End Results (SEER) Program to electronically supplement cancer surveillance data with Recurrence Score results. The prespecified primary analysis cohort was 40–84 years of age, and had node-negative, HR+, HER2-negative, nonmetastatic disease diagnosed between January 2004 and December 2011 in the entire SEER population, and Recurrence Score results (N=38,568). Unadjusted 5-year BCSM were 0.4% (n=21,023; 95% confidence interval (CI), 0.3–0.6%), 1.4% (n=14,494; 95% CI, 1.1–1.7%), and 4.4% (n=3,051; 95% CI, 3.4–5.6%) for Recurrence Score <18, 18–30, and ⩾31 groups, respectively (P<0.001). In multivariable analysis adjusted for age, tumor size, grade, and race, the Recurrence Score result predicted BCSM (P<0.001). Among patients with node-positive disease (micrometastases and up to three positive nodes; N=4,691), 5-year BCSM (unadjusted) was 1.0% (n=2,694; 95% CI, 0.5–2.0%), 2.3% (n=1,669; 95% CI, 1.3–4.1%), and 14.3% (n=328; 95% CI, 8.4–23.8%) for Recurrence Score <18, 18–30, ⩾31 groups, respectively (P<0.001). Five-year BCSM by Recurrence Score group are reported for important patient subgroups, including age, race, tumor size, grade, and socioeconomic status. This SEER study represents the largest report of prospective BCSM outcomes based on Recurrence Score results for patients with HR+, HER2-negative, node-negative, or node-positive breast cancer, including subgroups often under-represented in clinical trials.


Author(s):  
Mohammad Shoaib Abrahimi ◽  
Mark Elwood ◽  
Ross Lawrenson ◽  
Ian Campbell ◽  
Sandar Tin Tin

This study aimed to investigate type of loco-regional treatment received, associated treatment factors and mortality outcomes in New Zealand women with early-stage breast cancer who were eligible for breast conserving surgery (BCS). This is a retrospective analysis of prospectively collected data from the Auckland and Waikato Breast Cancer Registers and involves 6972 women who were diagnosed with early-stage primary breast cancer (I-IIIa) between 1 January 2000 and 31 July 2015, were eligible for BCS and had received one of four loco-regional treatments: breast conserving surgery (BCS), BCS followed by radiotherapy (BCS + RT), mastectomy (MTX) or MTX followed by radiotherapy (MTX + RT), as their primary cancer treatment. About 66.1% of women received BCS + RT, 8.4% received BCS only, 21.6% received MTX alone and 3.9% received MTX + RT. Logistic regression analysis was used to identify demographic and clinical factors associated with the receipt of the BCS + RT (standard treatment). Differences in the uptake of BCS + RT were present across patient demographic and clinical factors. BCS + RT was less likely amongst patients who were older (75+ years old), were of Asian ethnicity, resided in impoverished areas or areas within the Auckland region and were treated in a public healthcare facility. Additionally, BCS + RT was less likely among patients diagnosed symptomatically, diagnosed during 2000–2004, had an unknown tumour grade, negative/unknown oestrogen and progesterone receptor status or tumour sizes ≥ 20 mm, ≤50 mm and had nodal involvement. Competing risk regression analysis was undertaken to estimate the breast cancer-specific mortality associated with each of the four loco-regional treatments received. Over a median follow-up of 8.8 years, women who received MTX alone had a higher risk of breast cancer-specific mortality (adjusted hazard ratio: 1.38, 95% confidence interval (CI): 1.05–1.82) compared to women who received BCS + RT. MTX + RT and BCS alone did not have any statistically different risk of mortality when compared to BCS + RT. Further inquiry is needed as to any advantages BCS + RT may have over MTX alternatives.


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