@article {YAMAMOTO2439, author = {SHINYA YAMAMOTO and TAKASHI CHISHIMA and YUKAKO SHIBATA and FUMI HARADA and HIDEKI TAKEUCHI and AKIMITSU YAMADA and KAZUTAKA NARUI and TOSHIHIRO MISUMI and TAKASHI ISHIKAWA and ITARU ENDO}, title = {Clinical Impact of a Novel Model Predictive of Oncotype DX Recurrence Score in Breast Cancer}, volume = {35}, number = {4}, pages = {2439--2444}, year = {2021}, doi = {10.21873/invivo.12522}, publisher = {International Institute of Anticancer Research}, abstract = {Background/Aim: Oncotype DX recurrence score (RS) for breast cancer is a useful tool for determining chemotherapy indication but it is expensive and time-consuming. We determined whether four immuno-histochemical markers, namely human epidermal growth factor 2 (HER2), estrogen receptor (ER), progesterone receptor (PgR), and Ki-67, are predictive of an RS >=26 in Japanese patients. Patients and Methods: The study included 95 Japanese patients evaluated for RS. A predictive model was created using logistic regression analysis. Results: The discriminant function was calculated as follows: p=1/{1+exp [-(4.611+1.2342{\texttimes}HER2-0.0813{\texttimes}ER- 0.0489 {\texttimes}PgR+0.0857{\texttimes}Ki67)]}. Using a probability of 0.5 as the cutoff, the accuracy, sensitivity, specificity, positive predictive and negative predictive values were 90.5\%, 72.2\%, 94.8\%, 76.4\% and 93.5\%, respectively. Conclusion: The model had a high negative predictive value in predicting RS >=26 in Japanese patients, indicating that Oncotype DX testing may be omitted in patients with a negative result according to the predictive model.}, issn = {0258-851X}, URL = {https://iv.iiarjournals.org/content/35/4/2439}, eprint = {https://iv.iiarjournals.org/content/35/4/2439.full.pdf}, journal = {In Vivo} }