In breast cancer cases, lymph nodes in the armpit (known as axillary lymph nodes) are examined to assess metastatic spread and thus the prognosis and choice of treatment. A minor operation is performed, in which the first lymph nodes are identified and surgically removed for analysis. The procedure is minor but may cause pain, swelling, numbness and sometimes fluid collection.

The spread of cancer to the armpit affects approximately one in five breast cancer patients. The remaining 80% or so have no trace of cancer in the lymph nodes. In this case the procedure is purely diagnostic, with no therapeutic effect.

“In this study our focus has been on predicting the risk of metastasis in the armpit,” states Lisa Rydén, professor of surgery at Lund University and senior consultant at Skåne University Hospital.