58P - Survival benefit of local treatments in breast cancer with lung metastasis: Results from a large retrospective study

Background

Systemic therapy is the standard treatment for metastatic breast cancer. However, there has been growing interest in the use of metastasis-directed therapy in selected cases. We investigated the role of local treatments in prolonging survival for lung-only metastases (LM) from breast cancer after mastectomy. Systemic therapy is the standard treatment for metastatic breast cancer. However, there has been growing interest in the use of metastasis-directed therapy in selected cases. We investigated the role of local treatments in prolonging survival for lung-only metastases (LM) from breast cancer after mastectomy.

Methods

Medical records of breast cancer with LM with available clinical data at National Cancer Center in China between 2003 and 2019 were screened. Breast cancer patients with LM receiving local therapy + pharmacotherapy (LPT, n=110) or pharmacotherapy (PT, n=287) were included. Their clinicopathologic characteristics and prognosis were analyzed retrospectively.

Results

After screening a series of medical records of 3785 patients with metastatic breast cancer, 387 were confirmed as initial isolate LM. Patients receiving LPT had significantly longer median overall survival (OS) than those treated with PT: OS 78.9 months versus 53.2 months (P=0.009), respectively. The 3-, 5- and 10-year survival rates for LPT group were 78.3, 58.3 and 25.3%, and those for PT group were 61.8, 42.3 and 20.3% (P = 0.01), respectively. Cox multivariate analysis confirmed the survival benefit induced by LPT. Estrogen receptor (ER)-negative of the primary tumour, ki67>20%, disease-free interval from surgery to LM≤24 months, LM-associated symptoms, and patients receiving systemic pharmacotherapy only were independently associated with poor prognosis.

Conclusions

Adding local therapy to systemic pharmacotherapy might prolong survival for lung metastases in breast cancer. Well-designed randomised clinical trials are warranted in the future.

Clinical trial identification

Editorial acknowledgement

Legal entity responsible for the study

The authors.

Funding

Has not received any funding.

Disclosure

All authors have declared no conflicts of interest.