Abstract 221P
Background
Breast sarcoma is a rare type of breast tumor with different features and outcomes compared to carcinoma. Our study aims to describe the clinical and pathological characteristics of primary breast sarcoma (PBS) and secondary breast sarcoma (SBS) along with determining prognostic factors and developing nomograms for predicting survival.
Methods
Using the Surveillance, Epidemiology, and End Results (SEER) Program, female patients diagnosed with breast sarcoma between 1975 and 2016 were identified. Cox regression was used to evaluate the association between survival and clinical features. Nomograms for predicting survival of PBS and SBS were created based on significant factors in the multivariable Cox regression analysis and were evaluated using 10-fold-cross-validation.
Results
We included 1334 patients (816 PBS and 518 SBS). K-Meier survival analysis showed that PBS had a significant better OS than SBS (107 months for PBS and 45 for SBS). Cox regression showed worse survival of patient with PBS who were > 60 years (HR 3.04, 95% CI 2.46-3.74), had tumor size > 50 mm (HR 2.01, 95% CI 1.61-2.51). The same factors were also associated with significantly worse survival of SBS patients including age > 60 years (HR 2.00, 95% CI 1.42-2.82), tumor size > 50 mm (HR 1.72, 95% CI 1.35-2.21), with addational factor which is being not married (HR 1.50, 95% CI 1.19-1.90). Surgery was associated with better overall survival for PBS (HR 0.60, 95% CI 0.42-0.85) and SBS (HR 0.46, 95% CI 0.31-0.68). C-indexes of created nomograms were 0.73 for PBS and 0.69 for SBS. Multivariable Cox Proportional Hazard for OS. Table: 221P
| PBS | SBS | ||||||
| HR | 95% CI | P-value | HR | 95% CI | P-Value | ||
| Age | Age | ||||||
| >60 years | Ref. | <60 years | Ref. | ||||
| >60 years | 3.04 | 2.46-3.74 | <0.005 | >60 years | 2.00 | 1.42-2.82 | <0.005 |
| Metastasis | Marital Status | ||||||
| M0 | Ref. | Married | Ref. | ||||
| M+ | 5.24 | 3.67-7.49 | <0.005 | Not married | 1.50 | 1.19-1.90 | <0.005 |
| Tumor Size | Metastasis | ||||||
| < 50 mm | Ref. | M0 | Ref. | ||||
| >50 mm | 2.01 | 1.61-2.51 | <0.005 | M+ | 3.24 | 2.03-5.15 | <0.005 |
| Surgery | Tumor Size | ||||||
| No | Ref. | <50 mm | Ref. | ||||
| Yes | 0.60 | 0.42-0.85 | <0.005 | >50 mm | 1.72 | 1.35-2.21 | <0.005 |
| Chemotherapy | Surgery | ||||||
| No/Unknown | Ref. | No | Ref. | ||||
| Yes | 1.21 | 0.94-1.55 | 0.14 | Yes | 0.46 | 0.31-0.68 | <0.005 |
Conclusions
PBS had a better OS compared to SBS with hemangiosarcoma being the most common histologic subtype. Age, tumor size, and metastasis were the most important prognostic factors for the survival of PBS and SBS. Surgery was associated with better overall survival. However, radiation and chemotherapy did not show significant improvement in survival.
Legal entity responsible for the study
The author.
Funding
Has not received any funding.
Disclosure
The author has declared no conflicts of interest.