INTERVAL CANCERS AND CANCERS IN NONATTENDERS IN THE OSTERGOTLAND MAMMOGRAPHIC SCREENING-PROGRAM - DURATION BETWEEN SCREENING AND DIAGNOSIS,S-PHASE FRACTION AND DISTANT RECURRENCE

The study was based on a population mammographic screening programme f or women aged 40-74 years. Metastatic potential was analysed in 843 in vasive breast cancers with regard to mode of detection and a number of prognostic factors. There was a higher metastatic capacity in clinica lly detected cases, but multivariate analyses showed that neither the mode of detection (hazard rate ratio of distant recurrence RR = 1.39, 95% CI 0.78-2.46 interval cancers and RR = 1.6, 95% CI 0.76-3.36 non-a ttenders) nor the duration between screening and diagnosis for true in terval cancers (RR = 0.47, 95% CI 0.16-1.35 in tumours detected later than one year after screening) were independent prognostic factors. A correlation was found between metastatic potential and the SPF (RR = 2 .94, 95% CI 1.57-5.50 in tumours with a high SPF), the oestrogen recep tor status and the tumour stage. In conclusion, interval cancers intri nsically are not different from other breast cancers with equivalent c haracteristics; the duration between screening and diagnosis in interv al cancers was not clearly correlated to the prognosis, but the S-phas e fraction was a powerful predictor of prognosis. (C) 1997 Elsevier Sc ience Ltd.