THE RELATIONSHIP OF PATIENTS, GIVING OR NOT GIVING A PATHOLOGICAL FULL
RESPONSE, WITH YAP (YES ASSOCIATED PROTEIN) IN BREAST CANCER CASES TO
WHICH NEO-ADJUVANT CHEMOTHERAPY IS APPLIED
Abstract
Aim: We aimed to evaluate (immunohistochemically) the YAP expression in
breast cancer patients undergoing neoadjuvant chemotherapy and to
clarify the relationship between the molecular characteristics,
treatment response and survival data and the YAP expression, and hence,
to clarify the prognostic significance. Methods: One hundred and four
patients who were admitted to Erciyes University Faculty of Medicine
after the approval of the Ethics Committee and were diagnosed with
Breast Cancer between 2015-2020 and underwent NeoAdjuvant Chemotherapy
were included in the study. The diagnoses of these patients were
determined by any of the methods of Breast USG, Mammography, Breast MRI
and, if necessary, PET/CT, and among pathological samples, Estrogen
Receptor (ER), Progesterone Receptor (PR), Human Epidermal Growth
Receptor-2 (HER2) and Ki-67 Expression are routinely stained
immunohistochemically. In this study, existing immunohistochemical
markers were reviewed and also, the relationship of YAP with these
biological markers was evaluated by using immunohistochemistry and its
effect on prognosis has been investigated. Results: The average age of
the patients was 52.37. While YAP was positive in 78 patients (75%), it
was negative in 26 patients (25%). In the evaluation after neoadjuvant
therapy, pathological complete response (Miller Payne Grade 5 response)
in 28 patients (26.9%), relapse in 6 patients (5.8%), and exitus in 6
patients (5.8%) were detected. In the pathological evaluation, invasive
Ductal Carcinoma was the most common one observed in 88 patients
(84.6%). As a result of the statistical evaluation, no significant
result was obtained between the parameters and YAP negative / positive.
Conclusion: As a result of staining with additional YAP in patients who
were diagnosed with breast cancer and routinely stained with ER, PR,
Cerb B2 and Ki-67 in pathology samples, we could not reach a result that
would contribute positively to survival. Longer studies to be conducted
prospectively will be meaningful.