Targeted therapy with trastuzumab for epidermal growth factor receptor 2 (HER2)-positive advanced salivary duct...

Area of Science:

• Oncology
• Medical Genetics
• Pharmacology

Background:

• Salivary duct carcinoma is an aggressive malignancy.
• Treatment resistance to standard chemotherapy is a clinical challenge.
• Human epidermal growth factor receptor 2 (HER2) is a potential therapeutic target.

Purpose of the Study:

• To evaluate the efficacy of trastuzumab plus paclitaxel in patients with advanced salivary duct carcinoma and HER2 overexpression.
• To investigate the role of HER2 gene amplification as a predictive biomarker for treatment response.

Main Methods:

• Two cases of advanced salivary duct carcinoma with HER2 overexpression (3+ by immunohistochemistry) were treated with trastuzumab and paclitaxel.
• Dual fluorescence in situ hybridization (FISH) was used to assess HER2 gene amplification status.
• Clinical response was monitored after treatment initiation.

Main Results:

• One patient achieved a complete response lasting over 2.5 years.
• The second patient showed no response to the combination therapy.
• FISH analysis revealed HER2 gene amplification in the patient with a complete response, but not in the non-responding patient.

Conclusions:

• Trastuzumab plus paclitaxel may be a viable treatment option for HER2-positive salivary duct carcinoma.
• HER2 protein overexpression and gene amplification warrant further investigation as predictive biomarkers for targeted therapy.
• Individualized treatment strategies based on HER2 status are crucial for managing salivary duct carcinoma.