Surgical chemotherapy against lymph node metastases: an experimental study.

Area of Science:

• Oncology
• Pharmacology
• Surgical Oncology

Background:

• Surgical resection of primary tumors often leaves microscopic lymph node metastases undetected.
• Effective suppression of lymphatic spread is crucial for improving cancer patient outcomes.
• Topical delivery of anticancer agents to lymph nodes presents a potential strategy to combat micrometastases.

Purpose of the Study:

• To evaluate the efficacy of bleomycin emulsions for topical delivery to lymph nodes in suppressing lymphatic metastases.
• To compare the lymphatic transfer and sustained release of bleomycin using different emulsion types.
• To assess the impact of local bleomycin administration on lymph node metastasis and survival in a rabbit model.

Main Methods:

• VX2 tumors were transplanted into the vermiform appendix of domestic rabbits.
• Bleomycin was formulated into sphere-in-oil (S/O) and water-in-oil (W/O) emulsions for topical administration.
• Lymphatic transfer, sustained release, and tumor reduction in the drainage lymph node were analyzed.
• Survival rates of rabbits receiving different bleomycin formulations and administration routes were compared.

Main Results:

• Sphere-in-oil (S/O) emulsion significantly enhanced bleomycin transfer and sustained release into lymph nodes compared to W/O emulsion.
• Local administration of bleomycin as S/O or W/O emulsion resulted in complete reduction of lymph node metastases in 5 out of 7 rabbits.
• No survival prolongation was observed with topical or intravenous bleomycin solutions.

Conclusions:

• Topical bleomycin delivered via S/O or W/O emulsions is effective in eradicating lymph node metastases.
• Emulsion-based topical delivery enhances bleomycin's lymphatic transfer and sustained release, improving therapeutic potential.
• Local administration of anticancer emulsions offers a promising approach for managing lymphatic spread in cancer.