Freezing breast cancers to enhance complete resection.

Abstract

Cryoablation is currently being used to treat fibroadenomas and is being explored in clinical protocols as a potential treatment modality for highly selected small breast cancers without the need for surgical resection.1–6 The article by Tafra et al.7 demonstrates an additional use of cryoablation—to assist in the surgical resection of sonographically detectable, nonpalpable breast cancers. Cryoablation-assisted lumpectomy (CAL) allows three-dimensional localization of the lesion for resection by ultrasound guidance. As with cryoablation techniques, once the probe is positioned within the center of the tumor, liquid nitrogen or argon gas is used to generate a freezeball from the probe tip. This freezeball can be observed on real-time ultrasound to encompass the tumor and a margin of normal tissue. The proximity of the freezeball to the skin and pectoralis major muscle is monitored. If the freezeball approaches the skin or muscle, room temperature saline can be injected to create a separation and avoid tissue injury,1 as was used in this study. Tafra et al. showed some difficulty obtaining reliable tumor markers following CAL. For that reason, as with cryoablation, it is critical to perform a core biopsy before the cryo procedure to obtain accurate biologic tumor markers (e.g., estrogen or progesterone status and Her-2/neu).1,8 Several advantages of CAL over traditional wire localized excisional biopsy were demonstrated by Tafra et al.7 Because CAL is performed in the operating or procedure room, the patient does not have wire localization, which can be uncomfortable if placed before sedation. The freezing process itself acts as an anesthetic so the procedure is essentially pain-free for the patient1 and can be performed easily in an office setting with only local anesthesia or in the ambulatory surgical setting. The potential scheduling problems of coordinating preoperative wire localization, especially for an early morning surgical case, can also be avoided. CAL creates a palpable lesion from one that was initially not palpable, facilitating the ease of surgical resection. Tafra et al. demonstrated in those patients with a frozen margin of 6 mm or more beyond the sonographic limits of the tumor, the incidence of positive or close margins was reduced to 5.6%, compared with a 40% to 60% positive margin rate for wire localizations in the literature. Cryoablation-assisted lumpectomy is an interesting new option for the treatment of women with nonpalpable breast cancer. Clinical trials to further evaluate and compare CAL with traditional wire localized excision are currently underway.