Multi-faceted Approach That Includes Radiation Therapy Effective for Locally Advanced Breast Cancer

A phase 2 trial targeting locally advanced breast cancer (LABC) found primary systemic therapy involving chemotherapy followed by surgery and radiation therapy effective for patients with initially inoperable disease.

Although only 5 percent to 10 percent of the breast cancer diagnoses in the United States are LABC, this type accounts for up to 50 percent of cases in developing countries, according to Ricardo H. Alvarez, M.D., et al, in an original article published in this month’s Cancer at doi:10.1002/cncr.24910, www.interscience.wiley.com.

Primary systemic therapy is the current standard initial treatment for LABC, which includes inflammatory breast cancer. The regimen tested in the trial involved PST with doxorubicin and docetaxel followed by surgery, radiation therapy and adjuvant chemotherapy with cyclosphosphamide, methotrexate and 5-fluorouracil.

A total of 88 patients were evaluated, with 74 having an adequate response and 72 undergoing surgery. The trial resulted in an estimated five-year recurrence-free survival rate of 80 percent related to a complete pathological response; 77 percent related to a partial response; and 59 percent related to a minor response. The five-year overall survival rates were 90 percent, 91 percent and 74 percent, respectively.

Patients underwent six weeks of radiation therapy following adjuvant chemotherapy. After a modified radical mastectomy, participants were treated with 50.4 Gy at 1.8 Gy per fraction, in 28 fractions, to the chest wall or breast, supraclavicular region and internal mammary lymph nodes. A dose of 40 Gy to 50 Gy was administered to the midaxilla if pathologic findings included any of the following: a lymph node that measured 2.5 cm or greater, fixed or matted lymph nodes, an undissected axilla or pathologic evidence of extracapsular extension greater than 2 mm. In addition, a 10 Gy boost at 2 Gy per fractions, in five fractions, was applied to the chest wall after mastectomy, or to the primary breast tumor site, after 50.4 Gy or 50 Gy to the chest wall or breast. All patients with IBC were treated with accelerated, hyperfractionated irradiation, the authors noted.

“Multidisciplinary therapy that includes PST with DT and adjuvant therapy with CMF administered according to the clinical response is associated with high long-term RFS and OS,” Alvarez, et al, concluded.