A new breast cancer treatment uses an unusual method of administering chemotherapy— patients soak their breasts in hot water, which forces the chemotherapy drugs that are encapsulated in liposomes to release most of their contents into the breast tissue. The liposomal packaging melts above the usual body temperature (in this study, 104° F).
The encapsulation allows delivery of 30 times more of the drug to the breast tissue, without poisoning the rest of the body, according to researchers who reported on their study at the annual meeting of the American Society of Clinical Oncology. The 12-week, phase I trial of doxorubicin encased in liposomes (Myocet, The Liposome Company Inc.) and paclitaxel (Taxol, Bristol-Myers Squibb Company) is the only clinical trial of its kind in the U.S.
Of the 21 patients with newly diagnosed, large invasive breast tumors, 33% had complete remission; 17% were able to have lumpec-tomy instead of mastectomy, and 11% had complete pathologic responses. Tumor growth was arrested in all women in the study and half of the women had at least partial tumor shrinkage, even though many of the tumors were initially inoperable. Moreover, the researchers observed that nausea, fatigue, and cardiac tox-icity were lower than with traditional chemotherapy.
The study reversed the usual order of surgery, followed by chemotherapy and radiation. After a traditional infusion of chemotherapy, patients underwent hyperthermia drug treatments every three weeks for four cycles, followed by the least invasive surgery needed to remove the tumor. Additional chemotherapy and radiation might be needed postoperatively, the researchers say.