الفهرس 
EPIDEMIOLOGY AND RISK FACTORS OF BREAST CANCER
Personal history of breast cancerOnly 14 pages are availabe for public view
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Abstract
Breast cancer is the most frequently diagnosed malignancy,
accounting for over a million cases each year. It is also the
leading cause of cancer death in women worldwide. In the
United States, breast cancer is the most common female cancer,
the second most common cause of cancer death in women after
lung cancer, and the main cause of death in women ages 20 to
59 years (Siegel et al., 2013).
Breast cancer is the most common cancer among women
in Egypt. The proportion of breast cancer among Egyptian
females was 32.0% followed by liver cancer 13.5%. The age
standardized rate and the crude incidence rate for breast cancer
per 100,000 were 53 and 43.8 respectively (Amal et al., 2014).
Breast cancer (BC) is a heterogeneous disease not only in
clinical but also in biological features. The heterogeneity of BC
results in significant differences between certain histomolecular
subgroups in treatment efficacy and prognosis. Gene
expression profiling has led to identification 4 different
molecular subtypes (luminal A, luminal B, basal-like, HER2+)
(Prat et al., 2015).
Neoadjuvant chemotherapy (NAC), known as induction
or preoperative treatment, has been widely used to treat locally
advanced and inflammatory breast cancer. In addition, this
approach was introduced in operable BC with the initial aim to downstage the tumor for better loco-regional control and
increased conservative surgery rate (Minghao et al., 2017).
Another important advantage of using neoadjuvant
chemotherapy was an early identification of unresponsive
tumors; that gives an opportunity to terminate the ineffective
therapy and/or to switch to an alternative regimen (Angela
Pennisi et al., 2016).
It is well accepted that various subtypes of breast cancer
show different sensitivities to neoadjuvant chemotherapy
(Jiayu Wang et al., 2016).
Our study is aimed to evaluate the role of molecular
subtypes in predicting the response to neoadjuvant
chemotherapy among breast cancer patients at clinical oncology
department in Ain Shams university hospital.
A total of 102 patients were eligible for final analysis
with 76 patients presented with luminal subtype, 8 patients with
HER2 overexpression subtype and 18 cases with triple-negative
subtype.
The primary endpoint of this study was the pCR rate
according to molecular subtypes
Regarding pathological response for neoadjuvant
therapy, 9 patients achieved pCR (8.8%). The percentage of
pCR cases differed significantly among the 3 molecular subtypes with highest percentage in triple-negative subtype
38.9% (7/18).
Much lesser percentage for luminal subtype 2.6% (2/76)
being luminal B with her2neu negative result and no cases had
pCR in HER2-overpression subtype (0/8) (p<0.001)
In conclusion, molecular subtypes based on ER, PR,
HER2 and ki-67 can predict the pathological response of breast
cancer patients treated with neoadjuvant chemotherapy. pCR
rate varies significantly among different breast cancer
molecular sub-groups. pCR rate is higher in triple negative
breast cancer than HER 2 enriched and luminal subtypes.