O. Ahmed (Saskatoon, Canada)
Saskatoon Cancer Centre University of SaskatchewanAuthor Of 1 Presentation
- J. Hendry (Saskatoon, SK, Canada)
- S. Ali (Saskatoon, SK, Canada)
- O. Ahmed (Saskatoon, Canada)
- H. Chalchal (Regina, AB, Canada)
- A. El-Gayed (Saskatoon, Canada)
- K. Haider (Saskatoon, Canada)
- N. Iqbal (Saskatoon, Canada)
- K. Johnson (Saskatoon, Canada)
- D. Le (Saskatoon, Canada)
- B. Maas (Saskatoon, Canada)
- M. Manna (Saskatoon, Canada)
- M. Pauls (Saskatoon, Canada)
- M. Salim (Regina, AB, Canada)
- A. Sami (Saskatoon, Canada)
- P. Wright (Saskatoon, Canada)
- M. Younis (Saskatoon, Canada)
- S. Ahmed (Saskatoon, Canada)
59P - Outcomes of Women HER2 positive T1a/bN0M0 breast cancer treated with adjuvant trastuzumab: A retrospective population-based cohort study.
Abstract
Background
Adjuvant trastuzumab (TZM) improves outcomes of women with ≥T1c or node-positive HER2+ early-stage BC yet phase III trials are lacking in women with T1a/bN0 disease. Our study aims to assess outcomes of women with HER2+ T1a/bN0 BC who received adjuvant TZM in a Canadian province.
Methods
Women with HER2+ T1a/bN0 BC diagnosed during 2008-2017 in Saskatchewan were evaluated. Cox proportion multivariate analysis was performed to determine factors correlated with survival.
Results
91 eligible women with median age of 61 yrs (30-89) were identified. 47% had lumpectomy, 57% received adjuvant radiation and 58% received adjuvant endocrine therapy. 39 (43%) women received adjuvant TZM and 57% were in the control group. Women in the TZM group were significantly younger (57 vs. 65 yrs, p=0.02) and had a higher rate of T1b disease (92 vs. 40%, p<0.0001). All women in TZM group received chemotherapy vs. 1 woman in the control. 8% women developed recurrent breast cancer (3% in TZM vs. 12% in control, p=0.23). Median disease-free survival (DFS) was not reached. 5-year DFS was 94.8% in TZM group vs. 82.7 % in the control, p=0.22. 5-year invasive breast cancer-freesurvival was 97.4% in TZM vs. 94.2% in control, p=0.29. Median OS of control was 10.6 yrs and was not reached in the TZM group. 5-year survival was 100% in TZM group vs. 90.4% in the control (p=0.038). On multivariate analysis grade III tumor was significantly correlated with DFS (Hazard ratio [HR], 5.5, 95%CI: 0.92-9.5, p=0.004). Lack of adjuvant TZM (HR, 3.0, 95%CI: 0.92-9.5) did not correlate with DFS.
Conclusions
Overall outcomes of women with HER2+ T1a/bN0 BC is good. Women who received adjuvant TZM had numerically better DFS and a significantly better overall survival. High-grade tumor was correlated with inferior disease-free survival.
Legal entity responsible for the study
Shahid Ahmed.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.