e13065 Background: To analyze the correlation between tumor size and metastatic site in first-diagnosed stage IV breast cancer patients. Methods: Stage IV breast cancer patients diagnosed from 2010 to 2015 were screened by the Surveillance, Epidemiology, and End Results (SEER) database. The characteristics of clinical variables were represented by a frequency table, and the Chi-square test was used for comparison. At the same time, the Chi-square test was used to analyze the relationship between tumor size and organ metastasis. Correlation between tumor size and the prognosis of patients was contributed by KM curve and Log-rank test. Results: Regardless of tumor size, the proportion of bone metastasis was higher and brain metastasis was lower in breast cancer patients. There were significant differences in the site of metastases based on different subtype. Luminal A and Luminal B breast cancer had the highest proportion of bone metastases; brain metastasis accounted for the highest proportion in triple-negative breast cancer (TNBC); while the incidence of liver metastasis was the highest in Her-2(+) breast cancer. At the same time, the results indicated that Luminal A breast cancer with a tumor size > 5 cm was more likely to develop multi-site metastasis and lung metastasis, while Luminal B breast cancer with a tumor size ≤ 5 cm was more likely to develop liver metastasis. The results also revealed that TNBC patients with a tumor size of 0 - 2cm were more likely to develop bone metastasis than those with a tumor size > 5 cm, and the incidence of lung metastasis in triple-negative patients showed an increasing trend with the increase of tumor size. Conclusions: Based on subtype, we found that there was a significant difference between tumor size and metastatic site in patients with stage IV breast cancer, and the difference was statistically significant. This study provided evidence-based basis for decision-making of stage IV breast cancer treatment.
Association Between Background Parenchymal Enhancement and Pathologic Complete Remission Throughout the Neoadjuvant Chemotherapy in Breast Cancer Patients
