Cyclic AMP binding proteins and prognosis in breast cancer

Cyclic AMP binding proteins were measured in the primary tumour from 100 patients with non-disseminated breast cancer selected on the basis that sufficient tumour material was available for analysis. These measurements have been related to factors of established prognostic value and to the patients' disease-free interval and survival. There was a wide variation in amounts of binding proteins in different tumours. Values were significantly higher (P less than 0.05) in oestrogen receptor-negative tumours but no statistically significant correlations were apparent between levels and tumour grade or whether the patients had lymph node metastasis or adjuvant treatment. However, levels were significantly higher in patients whose disease recurred within 3 years of primary treatment as compared with those who remained disease-free. Using a retrospectively determined cut off point of 8 pmol mg-1 cytosol protein, it was shown that patients with tumour cyclic AMP binding in excess of this value had a significantly greater chance of developing recurrent disease and poorer survival rates (P less than 0.001 by Cox analysis) than those with lower levels. This remained true when other prognostic factors were taken into account in a multivariate analysis. It is suggested that the level of tumour cyclic AMP binding may be an independent prognostic factor for patients with early breast cancer.