Nuclear PARP-1 protein overexpression is associated with poor overall survival in early breast cancer

BACKGROUND

Poly(ADP-ribose)polymerase-1 (PARP-1) is a highly promising novel target in breast cancer. However, the expression of PARP-1 protein in breast cancer and its associations with outcome are yet poorly characterized.

PATIENTS AND METHODS

Quantitative expression of PARP-1 protein was assayed by a specific immunohistochemical signal intensity scanning assay in a range of normal to malignant breast lesions, including a series of patients (N = 330) with operable breast cancer to correlate with clinicopathological factors and long-term outcome.

RESULTS

PARP-1 was overexpressed in about a third of ductal carcinoma in situ and infiltrating breast carcinomas. PARP-1 protein overexpression was associated to higher tumor grade (P = 0.01), estrogen-negative tumors (P < 0.001) and triple-negative phenotype (P < 0.001). The hazard ratio (HR) for death in patients with PARP-1 overexpressing tumors was 7.24 (95% CI; 3.56-14.75). In a multivariate analysis, PARP-1 overexpression was an independent prognostic factor for both disease-free (HR 10.05; 95% CI 5.42-10.66) and overall survival (HR 1.82; 95% CI 1.32-2.52).

CONCLUSIONS

Nuclear PARP-1 is overexpressed during the malignant transformation of the breast, particularly in triple-negative tumors, and independently predicts poor prognosis in operable invasive breast cancer.

Adverse events risk associated with bevacizumab addition to breast cancer chemotherapy: a meta-analysis

BACKGROUND

Bevacizumab is a monoclonal antibody against vascular endothelial growth factor with the ability to increase progression-free survival in metastatic breast cancer (MBC). A systematic review and meta-analysis was conducted to determine the risk of the most clinically relevant adverse outcomes associated with the use of bevacizumab in the treatment of breast cancer.

PATIENTS AND METHODS

We included phase III clinical trials that used bevacizumab alone or in combination with chemotherapy as for MBC or locally recurrent. Statistical analyses were conducted to calculate summary odds ratio (OR) of the eight most relevant adverse outcomes related with bevacizumab.

RESULTS

Five clinical trials were included in the meta-analysis. Summary odds ratios obtained showed a statistically significant bevacizumab-associated increased risk in four of the adverse outcomes studied: proteinuria (OR = 27.68), hypertension (OR = 12.76), left ventricular dysfunction (LVD) (OR = 2.25), and hemorrhagic events (OR = 4.07). No statistically significant differences were found for gastrointestinal (GI) perforation, vascular events, fatal events, or febrile neutropenia.

CONCLUSIONS

Bevacizumab did increase the risk of LVD and hemorrhagic events. The addition of bevacizumab to chemotherapy in patients with metastatic breast cancer was not associated with a significant increase in grade ≥ 3 arterial or venous thromboembolic events, GI perforation, or fatal events.