A Pilot Study to Quantify Breast Lymphedema for Patients Undergoing Breast Conserving Therapy (BCT) for Breast Cancer

Abstract

<h3>Purpose/Objective(s)</h3> Upper extremity lymphedema after axillary lymph node dissection and radiation for breast cancer has been well described and studied. As modern treatment techniques have reduced the incidence of arm lymphedema, breast lymphedema has emerged as a common result of BCT and is associated with poor wound healing, infection and impact on quality of life. Because there is no established tool for its evaluation and quantification, we explored the feasibility of using ultrasound to measure breast lymphedema objectively. We evaluated whether this measure correlated with clinical assessment, treatment factors, and patient-reported outcomes. <h3>Materials/Methods</h3> We enrolled 30 women with malignant breast cancer treated with breast conserving surgery, sentinel lymph node biopsy, and breast radiation. Another 10 women with benign disease who had not undergone BCT were sampled as controls. Ultrasound measurements of dermal thickness were performed on the treated breast and untreated breast at the 6:00 position. Post-treatment assessments included physical exam and quality of life DASH questionnaire. We quantified breast lymphedema as the dermal thickness of the affected breast minus the dermal thickness of the unaffected breast. Breast lymphedema was considered present if dermal thickness difference was above the highest-observed value in the benign patients. <h3>Results</h3> Mean age (± SD) was SD 59 ± 13 in the malignant group and 46.4 ± 17 in the benign group and groups were similar with regard to body mass index. Mean dermal thickness difference was higher in the malignant group compared with the benign group (1.03 mm and 0 mm, respectively). Seventy percent of patients in the malignant group met our definition of breast lymphedema (n = 21) and were more likely to report impact on quality of life pertaining to sexual activity (24% vs 11%), breast sensation (52% vs 16%), sleep quality (33% vs 21%) and confidence (24% vs 5%) than patients without breast lymphedema. Extent of axillary surgery was associated with a 1.29 mm increase in difference in dermal thickness for patients with > = 4 nodes removed (95% CI: -0.22, 2.80). The volume of breast tissue radiated was also positively associated, with every 100cc increase in breast volume radiated associated with a 0.17mm greater dermal thickness difference (95% CI: 0.04, 0.30mm). However, there was no association with percent of breast tissue receiving > 105% of prescribed dose (95% CI: -0.07, 0.01), hypofractionation vs. standard fractionation (95% CI: -1.2, 0.68) or total radiation dose (95% CI: -0.5, 1.2). <h3>Conclusion</h3> Breast lymphedema is an impactful sequela of breast cancer treatment but remains understudied with no standard measurement tools. Our pilot study demonstrates that ultrasound is a promising tool for the characterization of breast lymphedema and may improve our understanding of patient and modifiable treatment risk factors.