43 Factors Affecting Survival in Solitary Bone-Only De Novo Stage IV Metastatic Breast Cancer

Background

The literature has revealed that patients with breast cancer who only have a solitary de novo solitary bone-only metastasis (dn-SBOMBC) have a good prognosis. Subgroup analysis of 10-year results of a RCT Protocol MF07-01 has demonstrated that patients in the solitary bone metastasis subgroup, median survival was 14 months longer in patients that had multimodal therapy compared with the systemic therapy only. The BOMET study has also demonstrated a significant 5-year survival benefit of 75% versus 45% in patients with dn-SBOMBC receiving multimodal therapy.

Materials and Methods

Data from the randomized clinical trial (MF07-01) and prospective registry (BOMET MF14-01) were combined and analyzed. The study included patients with solitary bone-only metastases who had survived more than 12 months after diagnosis. Age, tumor type, hormone receptor status, HER2 status, histological grade, lymphovascular invasion, T stage, number of metastases, chemotherapy, hormone therapy, bisphosphonate therapy, ovarian suppression, locoregional therapy (LRT), metastasis intervention, and progression were all analyzed. Kaplan-Meier survival and logistic regression analysis were used to compare the parameters.

Results

There were 205 patients in the solitary metastatic cohort, with a mean age of 52.25+12.9 years. The median follow-up time was 61 months (18-114). One-hundred and thirty (63.4%) patients underwent LRT. Ninety-eight (47.8%) patients had systemic progression, and 24 (11.7%) had loco-regional progression. The median overall survival (OS) was 87 (72-102) months. Parameters found significance in univariate analysis were entered into multivariate analysis. LRT (P = .043; RR, 0.32; 95% CI, 0.11-0.96) and ovarian suppression (P = .033; RR, 0.28; 95% CI, 0.88-0.90) were favorable prognostic factors for survival. In contrast, systemic progression was the sole independent risk factor that decreased survival in multivariate analysis (P < .001; RR, 21; 95% CI, 9.3-49.9).

Conclusions

This prospectively collected data analysis shows that a subgroup of solitary dn BOMBC patients had prolonged survival and benefited from LRT. With advances in clinical oncology, patients with solitary dn SBOMBC should be discussed in tumor boards, and patients should be well informed regarding multimodality treatment options.

AFFILIATIONS:

Kazim Senol,¹ Aykut Soyder,² Ahmet Dag,³ Didem Can Trabulus,⁴ Ahmet Bilici,⁵ Mutlu Dogan,⁶ Hasan Karanlık,⁷ Serdar Ozbas,⁸ Atilla Soran⁹

¹General Surgery Department, Uludag University Faculty of Medicine, Bursa, Turkey.

²Department of Surgery, Acibadem Altunizade Hospital, İstanbul, Turkey.

³General Surgery Department, Mersin University Faculty of Medicine, Mersin, Turkey.

⁴Department of General Surgery, Istanbul Education Research Hospital, Istanbul, Turkey.

⁵Department of Medical Oncology, Medipol University, Istanbul, Turkey.

⁶Department of Medical Oncology, UHS Dr. Abdurrahman Yurtaslan Oncology Training and Research Hospital, Ankara, Turkey.

⁷Istanbul University Institute of Oncology, Turkey.

⁸Private Practice, Ankara, Turkey.

⁹Division of Surgical Oncology, Breast Surgical Oncology, UPMC Magee-Womens Hospital, University of Pittsburgh Medical Center, Pittsburgh, PA.