L

Lobular carcinoma in-situ: unlike ductal carcinoma in-situ (see entry), this is considered a risk factor for developing breast cancer rather than a true malignant lesion in itself. Usually an incidental finding at biopsy. Relative risks of developing breast cancer are increased in the presence of a strong family history (see entry).

Lymph node status: in breast cancer, positive axillary lymph nodes are associated with a worse prognosis compared to negative axillary lymph nodes. See breast cancer entry.

Lymphoedema: in breast cancer, this refers to a swelling of the arm on the side of the cancer, either as a result of the treatment received or because of the cancer that has blocked the draining lymphatic channels that the arm shares with the breast. The risk of spontaneous lymphoedema following treatment of the axilla by surgical dissection is approximately 5 - 10%, but varies according to how the swelling is assessed. The risk of lymphoedema is increased after minor injury or infection to the arm in question, and good skin care, preventative measures and early treatment is important. Similar lymphoedema rates are reported following axillary dissection, axillary sampling (see entry) with radiotherapy, or radiotherapy alone. Combining axillary dissection (see entry) with radiotherapy gives a much higher rate of lymphoedema, estimated at 30-40%. These combinations of treatments are rarely indicated, unless there is extensive cancer outside the confines of the axillary lymph nodes, into the surrounding fat. In these circumstances, the risk of lymphoedema as a result of tumour progression outweighs the risk of lymphoedema from the treatment, as does the risk of cancer progression without treatment. The addition of supraclavicular fossa (base of the neck) radiotherapy to the treatment field on the side of the breast cancer is indicated in certain circumstances. This additional treatment increases the risk of lymphoedema after axillary surgery or radiotherapy (see also radiotherapy entry).