KIBRA; a novel biomarker predicting recurrence free survival of breast cancer patients receiving adjuvant therapy.

BACKGROUND: This study was carried out to evaluate the prognostic value of KIBRA in breast cancer. METHODS: This retrospective study included breast cancer patients who sought the services of the immunohistochemistry laboratory of our unit from 2006 to 2015. Tissue microarrays were constructed and immunohistochemical staining was done to assess the KIBRA expression. The Kaplan-Meier model for univariate and Cox-regression model with backward stepwise factor retention method for multivariate analyses were used. Chi square test was used to find out the associations with the established prognostic features. RESULTS: A total of 1124 patients were included in the study and KIBRA staining of 909 breast cancers were available for analysis. Cytoplasmic KIBRA expression was seen in 39.5% and nuclear expression in 44.8%. Overall KIBRA-low breast cancers accounted for 41.5%. KIBRA nuclear expression was significantly associated with positive ER and PR expression. Luminal breast cancer patients who had endocrine therapy and KIBRA-low expression had a RFS disadvantage over those who were positive for KIBRA (p = 0.02). Similarly, patients who received chemotherapy and had overall KIBRA-low expression also demonstrated a RFS disadvantage compared to those who had overall positive KIBRA expression (p = 0.018). This effect of KIBRA was independent of the other factors considered for the model. CONCLUSION: Overall low-KIBRA expression has an independent effect on the RFS and predicts the RFS outcome of luminal breast cancer patients who received endocrine therapy and breast cancer patients who received chemotherapy.

Elevated pre-surgical CA15-3: does it predict the short-term disease-free survival of breast cancer patients without distant metastasis?

BACKGROUND: CA15-3 is the most commonly used tumor marker in breast cancer. Its prognostic role has been described in the metastatic setting, but the role of pre-surgical CA15-3 in the assessment of patients with breast cancer without metastasis has not been substantiated yet. METHODOLOGY: From February 2014 for a 2-year period, this prospective study included all patients who were diagnosed with primary breast cancer and underwent surgery at a tertiary care hospital. The serum level of CA15-3 was assessed on a pre-surgical blood sample and later at the 3-, 6-, 9-, and 12-month follow-up by enzyme-linked immunosorbent assay. Disease-free survival (DFS) was analyzed with a Kaplan-Meier model and log-rank test. RESULTS: We enrolled 195 patients (mean age ± SD 57.84 years ±13.819, range, 28-95) with breast cancer. The prevalence of elevated (≥30 U/mL) pre-surgical CA15-3 was 35.9%, and it reduced to 14.3% at 3 months after mastectomy. Pre-surgical CA15-3 had a significant association only with the size of the tumor (p=0.047). Patients who did not have elevated pre-surgical CA15-3 (≥30 U/mL) had the best short-term DFS, and it was worst when the pre-surgical CA15-3 was >100 U/mL (p=0.041). CONCLUSION: Elevated pre-surgical CA15-3 is a predictor of poor short-term DFS of patients with breast cancer without distant metastasis.