Tumour regression and prognosis: a clinical study.

In advanced carcinoma of the uterine cervix reduction in the size of the tumour at the end of external beam radiotherapy closely correlated with subsequent local tumour control, freedom from metastasis and survival. A histological assessment of response showed a weaker correlation with subsequent events. In carcinoma of the bronchus the reduction in bulk of tumour assessed radiologically and the disappearance of tumour cells from the sputum did not correlate with the duration of survival. In the observation of tumour response the considerable differences which must be expected when comparing different tumours should not detract from the current and potential value of such studies.