CHICAGOBreast conservation followed by radiotherapy is an effective treatment approach for invasive breast cancer in medically indigent black women, but prompt initiation of the radiotherapy and adequate radiation dose are necessary to achieve optimal results, according to a study presented at the 85th Annual Meeting of the Radiological Society of North America (RSNA).
In this study, women who received radiotherapy within 30 days of lumpec-tomy had superior disease-free survival, compared with those in whom radiotherapy was delayed. Women who received a dose of at least 50 Gy achieved a greater degree of local control as well as longer disease-free and overall survival than those given lower doses, said Stuart H. Burri, MD, chief resident in Radiation Oncology, Emory University.
Dr. Burri and his colleagues reviewed the records of 88 black women who underwent breast-conservation therapy between 1980 and 1996 at Emorys Grady Memorial Hospital. Most were uninsured or receiving Medicaid. Of these 88 women, 72 had invasive cancer: 56% stage I disease; 37.5% stage II; 5.6% stage III; and 33% had positive lymph nodes.
Following lumpectomy, radiotherapy was delivered to the involved breast by means of opposed tangents. The dose ranged from 45 to 55 Gy (median, 50 Gy), and 70% received a radiation boost (median dose, 10 Gy). Radiotherapy was delivered between 9 and 312 days after lumpectomy (median, 69 days). The average follow-up was 55.4 months.
The proportion of women with invasive breast cancer who had local control of their disease was 95% at 5 years and 88% at 10 years. Disease-free survival was 85% at 5 years and 65% at 10 years, and overall survival was 77% at 5 years and 43% at 10 years.
Local control, disease-free survival, and overall survival were inferior among women who received a radiotherapy dose to the tumor bed of less than 50 Gy (P < .0001). Treatment failure was more likely if radiotherapy was delayed for more than 30 days after lumpectomy (P = .0479).
Dr. Burri explained that the method of notifying patients of the need for radiotherapy was most likely responsible for the extended intervals between surgery and further treatment experienced by some patients. Patients typically were notified by mail to return for further therapy after lumpectomy, but indigent patients can be difficult to contact by mail, because they tend to move frequently or do not have a mailing address.
Mailings also have been delayed by inefficiencies in the hospital mailing system. We have made efforts in recent years to decrease that time, and it has improved recently, Dr. Burri said.