Selective avoidance of lymphatic irradiation in the conservative management of breast cancer.

High-dose lymphatic irradiation is a contributory factor to the morbidity of treatment after local excision and high-dose radiotherapy for early stage breast cancer and may detract significantly from the cosmetic result. The apparent inability of lymphatic irradiation to influence the survival of patients with early stage breast cancer supports an argument for the selective avoidance of regional radiotherapy in a proportion of patients. Based on a review of the effects of lymphatic radiotherapy on lymphatic control, complications, cosmesis, survival and the effects of withholding lymphatic irradiation, recommendations are made for the selective treatment of patients at high risk of regional recurrence. In patients submitted to full axillary dissection, node negative patients require no lymphatic irradiation. After full axillary dissection radiotherapy is confined to the supraclavicular fossa in patients with heavy axillary involvement. A policy for patients having limited axillary dissection is discussed which identifies approximately 50% of patients as eligible for careful watch policy following local excision and high-dose radiotherapy to the primary disease.