Lumpectomy and Partial Breast Irradiation - Risks and Benefits for Early Breast Cancer

Abstract

Breast-conserving surgery followed by radiation therapy is the standard local treatment of early primary breast cancer. Radiation therapy limited to the part of the breast closest to the site of the excised tumor (accelerated partial breast irradiation, APBI) might be beneficial for these patients, but definitive results of ongoing trials should be awaited. Partial breast intraoperative radiation (IORT) has recently been developed to further improve the results of partial irradiation. Given that tumornegative margins are required for IORT, Schiller et al. considered how to identify and select patients for IORT by predicting those with tumorfree excision margins. The authors analyzed data from 708 patients who underwent 730 lumpectomies and found a 17% rate of positive margins at first resection. They could accurately (98%) predict negative margin status for the subset of patients older than 50 years with a preoperative core needle biopsy (CNB) showing invasive cancer less than 3 cm that can be localized under ultrasound. Are these patients truly ideal for consideration of IORT, as the authors suggest? What about the other subsets of patients including those aged <50 years, with a family history of breast cancer, extensive intraductal component, and multicentricity and multifocality? Local recurrence after lumpectomy or breast-conserving surgery still remains a substantial problem despite modern radiation therapy, with a local relapse rate of 10% or greater at 10 or 20 years after therapy. Young age, family history, BRCA1/2 mutation carriers and positive or close resection margins are considered risk factors for local recurrence after breast-conservation therapy (BCT). Partial breast irradiation either as APBI or IORT is probably an inappropriate treatment for patients at high risk of local recurrence. Treatments that achieved a reduction in local recurrence were also associated with a reduction in mortality after long-term follow up in a recent landmark meta-analysis of randomized trials. Thus, every effort should be made to achieve local control. This principle of local control appears to be important also for other solid cancers, such as, gastric cancer. Overall, prognosis of gastric cancer is poor with exception early-stage gastric tumors. Despite the validation of the efficacy of adjuvant systemic chemotherapy, local control with adequate D2 surgery or D1 surgery plus chemoradiotherapy may improve survival. There is currently a trend toward less extensive surgery and partial breast irradiation with the aim of reducing adverse effects and improving quality of life, but strong evidence is needed that these modern therapies are safe and do not increase local recurrence or reduce overall survival. Research on molecular and genetic biomarkers already provides promising findings towards personalized treatment. 26–28 More work is required for prospective validation before these markers can be used in the clinic for selecting breast cancer patients for minimal surgery and partial breast irradiation. Published online February 1, 2008. Address correspondence and reprint requests to: D. Ziogas, MD; E-mail: deziogas@hotmail.com