Focused microwave thermotherapy for preoperative treatment of invasive breast cancer: a review of clinical studies.
BACKGROUND
Preoperative focused microwave thermotherapy (FMT) is a promising method for targeted treatment of breast cancer cells. Results of four multi-institutional clinical studies of preoperative FMT for treating invasive carcinomas in the intact breast are reviewed.


METHODS
Externally applied wide-field adaptive phased-array FMT has been investigated both as a preoperative heat-alone ablation treatment and as a combination treatment with preoperative anthracycline-based chemotherapy for breast tumors ranging in ultrasound-measured size from 0.8 to 7.8 cm.


RESULTS
In phase I, eight of ten (80%) patients receiving a single low dose of FMT prior to receiving mastectomy had a partial tumor response quantified by either ultrasound measurements of tumor volume reduction or by pathologic cell kill. In phase II, the FMT thermal dose was increased to establish a threshold dose to induce 100% pathologic tumor cell kill for invasive carcinomas prior to breast-conserving surgery (BCS). In a randomized study for patients with early-stage invasive breast cancer, of those patients receiving preoperative FMT at ablative temperatures, 0 of 34 (0%) patients had positive tumor margins, whereas positive margins occurred in 4 of 41 (9.8%) of patients receiving BCS alone (P = 0.13). In a randomized study for patients with large tumors, based on ultrasound measurements the median tumor volume reduction was 88.4% (n = 14) for patients receiving FMT and neoadjuvant chemotherapy, compared with 58.8% (n = 10) reduction in the neoadjuvant chemotherapy-alone arm (P = 0.048).


CONCLUSIONS
Wide-field adaptive phased-array FMT can be safely administered in a preoperative setting, and data from randomized studies suggest both a reduction in positive tumor margins as a heat-alone treatment for early-stage breast cancer and a reduction in tumor volume when used in combination with anthracycline-based chemotherapy for patients with large breast cancer tumors. Larger randomized studies are required to verify these conclusions.
Dooley
William C
WC
Health Sciences Center, The University of Oklahoma, Oklahoma City, OK, USA. william-dooley@ouhsc.edu
Vargas
Hernan I
HI
Fenn
Alan J
AJ
Tomaselli
Mary Beth
MB
Harness
Jay K
JK
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001943:Breast Neoplasms / Q000473:pathology / Q000628:therapy*; D018270:Carcinoma, Ductal, Breast / Q000473:pathology / Q000628:therapy*; D017321:Clinical Trials, Phase I as Topic; D017322:Clinical Trials, Phase II as Topic; D005260:Female; D006801:Humans; D006979:Hyperthermia, Induced; D008872:Microwaves / Q000627:therapeutic use*; D008875:Middle Aged; D015337:Multicenter Studies as Topic; D016032:Randomized Controlled Trials as Topic; D015996:Survival Rate; D016896:Treatment Outcome