A Randomized Phase III Study of Hypofractionated versus Standard Radiotherapy after Conservative Surgery for Early Breast Carcinoma

Abstract

Breast cancer is the second most common cause of death in all cancer female patients. The American Cancer Society estimated that 235,030 new cases of invasive breast cancer were diagnosed in the United States during 2014, of which approximately 40,430 women were expected to die from it (Siegel et al., 2014). In Egypt, breast cancer is the most common cancer in females, it represents 26.8% of all cancer cases in Minia female registry 2009 & 32.9% of all cancer female cases in Damietta cancer registry 2009 (NCI, 2010). Radiotherapy reduces the risk of local relapse and breast cancer mortality and is offered to nearly all patients after conservative surgery (Clarke et al., 2005). The high number of women with breast cancer, receiving postoperative RT, led to think that a shorter course of irradiation would result in improved quality of life for patients, in potentially better integration with systemic treatments and in reduced costs. Therefore, alternative schedules based on a lower total dose delivered in fewer, larger fractions (hypo-fractionation) were firstly introduced in Canada and the United Kingdom (Owen et al., 2006). Our study is a phase III prospective open labeled randomized clinical trial conducted in Clinical Oncology and Nuclear Medicine Department, Ain Shams University Hospitals, during the period between January 2013 to April 2014. The study included Fifty Four eligible patients with early breast cancer who were classified into two groups; twenty seven patients in each group.

Group I received Hypo-fractionated postoperative radiotherapy; they were treated with whole breast irradiation of 45 Gy in 20 fractions, 2.25 Gy/fraction followed by 9 Gy in 3 fractions as a boost dose to the tumor bed, while Group II received Conventional postoperative radiotherapy; they were treated with conventional fractionation of 2 Gy to a total dose of 50 Gy in 25 fractions followed by a boost dose of 10-16 Gy in 5-8 fractions to the tumor bed. Pre-radiotherapy assessment included history taking and clinical examination, assessment of performance status, Bilateral sonomamograph, Pathology confirmed invasive ductal or lobular breast cancer with Immunohistochemistry ER, PR, Her 2 neu and Ki 67, Investigations including chest x-ray, bone scan, pelvic and abdominal U/S or CT, Full blood count, Kidney and Liver function tests, echocardiograph. Then after receiving adjuvant chemotherapy, if indicated, patients underwent a baseline high resolution CT Chest, and then submitted to one of the two arms.