Adjuvant Sequential Chemotherapy for Salivary Duct Carcinomas: A Retrospective Comparative Analysis

Area of Science:

• Oncology
• Medical Oncology
• Cancer Treatment

Background:

• Salivary duct carcinoma (SDC) is a rare and aggressive malignancy.
• Standard treatment involves surgery and postoperative radiation therapy.
• The role of adjuvant chemotherapy in SDC remains unclear.

Purpose of the Study:

• To evaluate the efficacy and safety of adjuvant sequential chemotherapy following definitive treatment for SDC.
• To compare outcomes between patients receiving surgery plus radiation therapy with those receiving additional chemotherapy.

Main Methods:

• Retrospective study of 135 pathologically confirmed SDC patients (2009-2022).
• Comparison of outcomes (overall survival, disease-free survival, distant metastasis-free survival) between surgery + radiation + chemotherapy (n=55) and surgery + radiation (n=80) groups.
• Propensity score matching (PSM) analysis was employed to control for confounding factors.

Main Results:

• Adjuvant chemotherapy (cisplatin-based) was generally well-tolerated with minimal adverse events.
• Multivariable analyses and PSM did not show statistically significant improvements in overall survival, disease-free survival, or distant metastasis-free survival with the addition of chemotherapy.
• A trend favoring adjuvant chemotherapy in overall survival was observed but did not reach statistical significance.

Conclusions:

• Current cisplatin-based adjuvant chemotherapy does not significantly enhance treatment outcomes for SDC patients compared to surgery and adjuvant radiation alone.
• Further clinical studies are essential to explore novel chemotherapeutic agents, biomarkers, immune checkpoint inhibitors, and improved treatment strategies for SDC.