Cancer research campaign (King's/Cambridge) trial for early breast cancer. A detailed update at the tenth year. Cancer Research Campaign Working Party.

In the tenth year of follow-up of a multicentre trial of the management of operable breast cancer no significant difference in survival was found between patients treated with simple mastectomy alone (with radiotherapy later if the disease recurred) and those treated with simple mastectomy and routine immediate postoperative radiotherapy. There was a highly significant increased risk of local recurrence in the conservatively treated group, with a hazard ratio of 3.0. The biological and clinical relevance of these results is discussed.