The Cancer Research Campaign (King's/Cambridge) trial for early breast cancer: an analysis of the radiotherapy data.

A detailed study has been made of the patients receiving routine post-operative radiotherapy in the Cancer Research Campaign trial for early breast cancer. Particular attention has been paid to the routine dose delivered and the incidence of recurrence in different areas. Little difference was apparent in the incidence of local recurrence in groups of patients receiving different levels of dosage, although there was a threefold reduction in five-year local recurrence-free rates compared with that for patients who received no irradiation. Moderate or severe telangiectasis occurred more frequently as the dose increased. When analysed in terms of survival, there was a tendency for the patients receiving more than 1510 ret to do a little better, but this was not statistically significant and could be due to some unexplained patient selection or higher dosage. There was no suggestion that irradiation might cause reduced survival.