Outcome of HER2 positive luminal operable breast cancer in comparison with outcome of other operable luminal breast cancer patients: Long follow-up of single center randomized study.
BACKGROUND
In clinical practice, there is increasing recognition that HER2-positive breast cancer patients are not a homogeneous group. Especially patients with luminal B breast cancers which are now subdivided to more than two groups.


OBJECTIVE
The aim of this study is to know the effect of HER2 positivity on luminal breast cancer patients by comparing disease free survival DFS luminal of HER2 positive breast cancer patients with other luminal cases with HER2 negative disease. Also we explored the effect of HER2 positivity on different risk factors for breast cancer.


METHODS
We compared the outcome of 25 HER2 positive luminal breast cancer patients with a control group of other luminal operable breast cancer at the same period of time with the same eligibility and exclusive criteria.


RESULTS
Total of 59 operable luminal breast cancer patients were eligible for the study, 25 of them were luminal HER2 positive and the 34 were control group of luminal HER2 negative. We found that HER2 positive luminal breast cancer patients were having more unfavorable risk factors and have more incidence of relapse mainly after 48 months follow-up than other luminal patients: after 24 months follow-up period HER2 positive luminal patients have cumulative DFS of 91% compared with 93% in luminal HER2 negative patients but after 48 months follow-up the difference between the two groups became more obvious as it was 66% for luminal HER2 positive group and 90 % for the control group. High risk patients for luminal HER2 positive breast cancer patients have higher risk of relapse (60% compared with 86%), and this appeared also in other subgroups.


CONCLUSIONS
HER2 positive luminal breast cancer patients have a higher incidence of relapse compared with other luminal breast cancer, and this difference appear mainly after 48 months of follow-up. High risk patients for luminal HER2 positive breast cancer have higher risk of relapse than high risk patients of other luminal patients.
Nasser Institute Oncology Center, Adult Oncology Unit, Egypt.
R
R
Abo El Hassan
National Cancer Institute, Department of Biostatistics and Human Epidemiology, Egypt.
M
M
Moneer