Ultrasound-guided breast-sparing surgery to improve cosmetic outcomes and quality of life A prospective multicentre randomised controlled clinical trial comparing ultrasound-guided surgery to traditional palpation-guided surgery (COBALT trial)
01 / 2010 - unknown
Rationale: Breast-conserving therapy (BCT) for breast cancer is initiated as a method to preserve healthy breast tissue, thereby improving cosmetic outcomes. The cosmetic outcome after breast cancer surgery is an important determinant of patient satisfaction, maintenance of self-image and quality of life. Thus far, the primary aim of BCT has been focused on achieving tumour-free resection margins and preventing local recurrence, while the cosmetic outcome has been considered less important. Large studies have reported poor cosmetic outcomes in 20-40% of patients after BCT, and the volume of resected breast tissue is the major determinant of the cosmetic outcome. In daily practice, surgical resection of palpable breast cancer is performed with guidance by intra-operative palpation. Concerns about tumor involvement of resection margins, however, often result in unnecessarily wide resection of adjacent healthy breast tissue. Our recent large multicentre retrospective study showed that in 32% (112/351) of patients over 200% excessive healthy breast tissue was excised with the malignant tissue! The mean volume excessively excised was 142 cm³ (64-423 cm³; sd 86)! There is clear evidence for the efficacy of ultrasonography (US) in the resection of nonpalpable tumours, and US is an easy available and feasible method for continuous visualisation during surgery. Intra-operative US reduces the resection of healthy breast tissue and improves tumour-free resection margins. In the present study, the value of the use of US during the resection of palpable tumours of the breast will be investigated. The objectives will be to determine whether US-guided resection of palpable breast cancer allows sparing of the breast tissue while preserving tumour-free resection margins with improvements in cosmetic outcomes and quality of life. Objectives: To reduce the extent of healthy breast tissue resection by US-guided surgery for palpable tumours compared to traditional palpation-guided surgery, without compromising oncological principles. To improve cosmetic outcomes and quality of life by US-guided surgery or palpable tumours. Study design: Prospective multicentre randomised controlled clinical trial. Study population: Women age 25-75 yrs who are diagnosed with palpable early-stage (T1-2N0-1) primary breast cancer and who are suitable for BCT. Intervention: US-guided surgery (USS). Control: Traditional palpation-guided surgery (PGS). Main study parameters: Primary outcome parameters are the volume of resected breast tissue excised (compared to the optimal resected volume) and the oncological margin status. Secondary outcome parameters are cosmetic outcomes and quality of life. Timeline and statistics: The inclusion period will run from June 2010 to December 2010, and 120 patients will be enrolled in this study (alpha 0.05; power 0.8), assuming that 25% of patients will obtain significant improvement in the cosmetic outcome by having a smaller amount of healthy breast tissue resected. The results will be analysed using a chi-square test, Student s t-test, Fisher s exact test and multiple regression analysis with the SPSS statistical package version 15.0.