Cryosurgery of breast cancer
E. D. Staren, M. S. Sabel, L. M. Gianakakis, G. A. Wiener, V. M. Hart, M. Gorski, K. Dowlatshahi, B. F. Corning, M. F. Haklin and G. Koukoulis
Department of General Surgery, Rush-Presbyterian-St Luke's Medical Center, Chicago, Ill., USA.
OBJECTIVE: To determine the feasibility and efficacy of cryosurgery of
breast cancer. DESIGN: In phase 1, carcinogen-induced mammary
adenocarcinomas in 13 Sprague-Dawley rats were treated by cryosurgery and
were then examined for histopathologic change. In phase 2, transplantable
mammary adenocarcinomas in 50 DBA/IJ mice were treated by cryosurgery to
determine the effect of varying tumor temperatures, and duration and number
of freeze-thaw cycles on tumor viability. In phase 3, 2- to 3-cm
ultrasound-monitored cryolesions were formed in the breasts of 4 dogs and 4
sheep. These animals were followed up for procedure-related complications;
the histopathologic necrosis of the cryolesions were correlated with the
ultrasound images. Based on the results of these experiments,
ultrasound-guided cryosurgery of breast cancer was initiated in a human
clinical trial. RESULTS: In phase 1, a single, short-term (< 7 minutes)
freeze killed only tumors smaller than 1.5 cm in diameter, despite an
apparent decrease to -40 degrees C at the periphery of each tumor. In phase
2, varying the peripheral tumor temperature to as low as -70 degrees C,
using a single, short-term (< 7 minutes) freeze did not alter the
results from phase 1. If the ice ball fully encompassed the tumor, however,
maintaining it for at least 15 minutes achieved 100% tumor kill independent
of tumor size. In phase 3, creation of a reproducible ultrasound-monitored
cryolesion was facilitated when 2 freeze-thaw cycles were performed. No
procedure-related complications were noted. In the human trial, 2 invasive
lobular carcinomas from 1 patient were treated by cryosurgery and were
negative for persistent tumor by core needle biopsy performed 4 and 12
weeks after a well-tolerated procedure. CONCLUSIONS: In situ breast
cryosurgery has been proved to be feasible and efficacious in small and
large animal studies and has been successfully performed in 1 patient with
breast cancer. The results of this study suggest that ultrasound-guided
cryosurgery of breast cancer warrants further investigation.
