Securin immunopositivity predicts poor breast cancer outcome
MedWire News: Securin immunopositivity is an independent prognostic indicator for invasive breast cancer, Finnish research suggests.
In their study of 310 women with invasive breast cancer followed-up for an average of 10.5 post-operative years, the researchers found that low securin immunopositivity indicated a favorable course of disease, especially in association with low Ki-67 immunopositivity.
“Securin is a recently recognized oncogene with multiple known functions in initiation, progression, and cell cycle regulation in several malignant diseases, including breast carcinoma,” explain Kati Talvinen (University of Turku) and colleagues.
To investigate the prognostic value of securin, Talvinen and team immunostained tissue microarrays (TMA) prepared from archived breast cancer tissue from each of the patients. Positively stained securin and Ki-67 nuclei were registered as a percentage of the number of tumor cells, high securin positivity was defined as 1.5% or above, and high Ki-67 positivity was defined as 10.0% or above.
As reported in the British Journal of Cancer, securin predicted breast cancer-specific survival among all cases of invasive breast cancer as well as among subgroups divided according to histological type, Ki-67 proliferation status, and tumor size.
In a multivariate analysis adjusted for patient’s age, axillary lymph node status and tumor size at the time of diagnosis, the combination of high immunopositivity for both securin and Ki-67 indicated a 4.3-fold increased risk for breast cancer death as compared with the prognostic value of low securin and Ki-67.
Furthermore, securin immunopositivity was associated with a 13.1-fold increased risk for breast cancer death among patients with invasive ductal breast carcinomas and low Ki-67 positivity.
“Although the cut-off point may not directly be applicable to clinical material in whole sections, our results on TMA suggest that minimal or absent securin immunopositivity could indicate a more favorable outcome of disease than that concluded from Ki-67 immunopositivity alone,” say the researchers.
This suggests that “securin in combination with Ki-67 enhances the prognostic information derived from cell proliferation,” they add.
Talvinen and co-authors conclude: “Further investigations are needed to evaluate the possible prognostic and therapeutic applications of securin in treatment decisions of individual breast cancer patients.”
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By Laura Dean