We collected information from 814 women consecutively treated with adjuvant radiotherapy for breast cancer. The women had breast surgery with axillary dissection (AD) or sentinel node biopsy (SNB). The breast area was treated to 50 Gy in 2.0 Gy fractions. Women with >three lymph node metastases had regional radiotherapy (RRT) to the supraclavicular lymph nodes. Three to eight years after radiotherapy, they received a questionnaire asking about paraesthesia, oedema, pain, and strength in the upper limb.
Paraesthesia was reported by 38/192 (20%) after AD with RRT compared to 68/505 (13%) after AD without RRT (relative risk [RR] 1.47; 95%confidence interval [CI] 1.02-2.11) and by 9/112 (8%) after SNB without RRT (RR 2.46; 95%CI 1.24-4.90). Corresponding risks adjusted for oedema (RR 1.28; 95%CI 0.93-1.76) and (RR 1.75; 95%CI 0.90-3.39). In women 猢?9 years with AD and RRT, 27%reported paraesthesia. No significant pain or decreased strength was reported after RRT.
Radiotherapy to the supraclavicular lymph nodes after axillary dissection increases the occurrence of paraesthesia, mainly among younger women. When adjusted for oedema the contribution from radiotherapy is no longer formally statistically significant indicating that there is also an indirect effect mediated by the oedema.