J Cancer 2019; 10(12):2635-2642. doi:10.7150/jca.32453 This issue
1. Department of Biostatistics, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
2. Department of Breast Medical Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
3. Department of Medical Oncology, The National Cancer Institute, Cairo University, Cairo, Egypt
4. Department of Pathology, Division of Pathology/Lab Medicine, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
5. Department of Breast Surgical Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
6. Department of Radiation Oncology, Division of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
7. Morgan Welch Inflammatory Breast Cancer Research Program and Clinic, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
Background: Research on the prognostic or predictive value of Ki-67 among patients with inflammatory breast cancer (IBC) is limited.
Methods: Using the comprehensive database of the Morgan Welch Inflammatory Breast Cancer Research Program at MD Anderson Cancer Center, we identified a cohort of breast cancer patients who were diagnosed with IBC between 1992 and 2012. Distributions of survival outcomes were estimated by the Kaplan-Meier method and compared by log-rank tests and Cox models.
Results: Among a total of 257 patients with stage III IBC, the mean percentage of tumor cells that stained positive for Ki-67 was 48%, (range, 4% to 100%). Using a cutoff of 20% as being Ki-67 positive, this characteristic tended to be associated with worse overall survival (p=0.07) in the univariate analysis. After controlling for hormone receptor (HR) status, human epidermal growth factor receptor 2 (HER2) status and having received trimodality treatment, the association between Ki-67 status and overall survival remained marginally significant (p=0.07). The effects of trimodality treatment on overall survival were statistically significantly different between patients with Ki-67-positive tumors (hazard ratio=0.26, 95% confidence interval [CI]=0.15-0.44, p<0.01) and those with Ki-67-negative tumors (hazard ratio =2.04, 95% CI=0.45-9.29, p=0.36) after adjusting for other tumor characteristics (p=0.01).
Conclusion: IBC patients with Ki-67-positive tumors tended to have worse overall survival, but were more likely to benefit from trimodality treatment, with better overall survival and distant metastasis-free survival. Patients with Ki-67-negative tumors had similar survival distributions, regardless of whether they received trimodality treatment.
Keywords: Inflammatory breast cancer, Ki-67, Metastasis-free survival, Overall survival, Trimodality treatment