Effects of fine-needle aspiration and other biopsy procedures on tumor dissemination in mice.

Using five syngeneic tumor-host systems in mice, we studied the influence of fine-needle aspiration biopsy, incisional biopsy, and excisional biopsy on tumor death rates. Guided by results from pilot studies a very strict test protocol was developed which made possible a comparison between the tumor systems in spite of their differences in tumor growth rates and dissemination patterns. The compiled results from the experiments did not reveal any differences in tumor death rates, neither between the test groups and their controls, nor between the three biopsy methods: fine-needle aspiration biopsy, incisional biopsy, and excisional biopsy. Additional experiments confirmed, however, earlier observations that tumor cell seeding and tumor outgrowth by way of the aspiration needle track may occur under extreme test conditions.