|The following article features coverage from the American Society of Hematology (ASH) 2018 meeting. Click here to read more of Oncology Nurse Advisor‘s conference coverage.|
Breast-conserving surgery (BCS) and radiotherapy (RT) do not interfere with the mechanical integrity of the shoulder according to a study presented at the 2018 San Antonino Breast Symposium. Breast conserving surgery and radiotherapy reduce the risk of breast cancer recurrence; however, the treatment has been reported to cause pain, stiffness, and restricted mobility in the shoulders of breast cancer survivors.
This study assessed the mechanical integrity of the shoulder, including the pectoralis major in patients with breast cancer 1 year after BCS and RT. Patients were divided into 2 groups. Group 1 included 9 patients with node-negative breast cancer who were treated with 2 RT fields to the breast after BCS and sentinel node biopsy. Group 2 included 9 patients with node-positive breast cancer who were treated with more than 3 RT fields to the breast and draining lymphatics post BCS and axillary lymph node dissection (ALND). The 2 groups were compared with 9 healthy patients with no history of breast cancer or shoulder injury (controls).
Shoulder stiffness was measured using robot-assisted biomechanical measurements. Stiffness of the clavicular and sternocostal fiber regions of the pectoralis major were evaluated using ultrasound. No significant difference in shoulder stiffness was seen between the treatment groups and the healthy controls. But, a significant difference in pectoralis major shear elastic modulus was noted between the 2 groups. Stiffness in the sternocostal and clavicular regions were an average of 14% to 21% greater and 12% to 18% greater, respectively, in the group 2 patients compared with the group 1 patients and the healthy controls. No difference was seen between the group 1 patients and the controls.
The study authors concluded, “Although power is limited due to small sample size, this study provides the first evidence that the mechanical integrity of the shoulder remains intact in patients who receive ALND combined with a supraclavicular field (generally without full axillary radiotherapy).”
Lipps DB, Leonardis JM, Lehmann S, et al. Mechanical properties of the shoulder and pectoralis major in women undergoing breast conserving therapy with axillary dissection and regional nodal radiotherapy versus sentinel node biopsy and radiotherapy to the breast alone. Poster presentation at: 2018 San Antonio Breast Cancer Symposium; December 4-8, 2018; San Antonio, TX. Abstract P1-12-18.