Work

The patterns of systemic metastasis in major salivary gland cancer and therapeutic implications

Year: 2025

Type: article

Abstract: BACKGROUND: This study aimed to investigate the patterns of metastatic spread of salivary gland cancer (SGC) and their therapeutic implications. Patterns of systemic metastasis, post-metastasis survival, and risk factors have not been defined clearly in SGC, and the validity of the concept of oligometastasis in SGC has never been explored. METHODS: This was a retrospective study of SGC patients with systemic metastasis (N = 199). The primary outcome was post-metastasis disease-specific survival, and multivariable survival analyses for risk factors were performed. The patients were divided into three pathology groups, adenoid cystic carcinomas (ACCs), non-ACC high-grade tumors, and non-ACC intermediate or low-grade tumors. RESULTS: Median survival was 28.9 months after diagnosis of systemic metastasis. Only 30 % of patients had oligometastasis (≤ 3 metastatic lesions and ≤ 2 involved organs), and polymetastasis was observed in 70 % (33.7 % single organ polymetastasis and 36.2 % multi-organ polymetastasis). Poor patient performance status, shorter metastasis-free interval, non-ACC high-grade tumor, concurrent local disease, and multi-organ polymetastasis were identified as independent risk factors for post-distant metastasis survival. Of note, SGC patients with oligometastasis and single organ polymetastasis showed similar survival outcomes. Systemic chemotherapy did not improve post-metastasis survival of SGC patients significantly. However, HER-2 targeted therapy combined with chemotherapy extended post-metastasis survival in c-erb-B2 expressing tumors. CONCLUSIONS: Systemic metastasis into multiple organs is a common pattern of SGC metastasis, and significantly affects patient survival. Tumor biology-based therapy should be further sought for improving post-metastasis outcomes of SGC patients.

Source: Oral Oncology

DOI: 10.1016/j.oraloncology.2025.107258