[Comparative prognostic study of the in vitro and in vivo development of colorectal tumors. Preliminary communication].

In vitro clonal growth of tumour cells may reflect biological properties of cancer and thus have prognostic value. This study seeks to establish correlations between the clinical outcome in patients after surgery for colorectal cancer and clonal growth of their tumours. History, status and follow-up data are collected. Tumour samples taken at operation under sterile conditions are plated immediately in our methylcellulose clonal assay system. Out of 65 consecutive samples, 3 did not yield sufficient cells for culture. Thirty-four (55%) grew more than 0.3 colonies/10(5) cells seeded; cloning efficiency was greater than 10 colonies/10(5) cells in 19. The 28 (45%) failures included 3 benign polyps cultured; 7 samples had visible bacterial or fungal contamination. The other 18 negative cultures may be due to cytotoxicity of the antibiotics or heterogeneity of tumour cells. These preliminary results show that colorectal cancers grow well in vitro in the absence of restricting factors, but they do not confirm the hypothesis that proliferative potential and differentiation are opposing processes. Location of the tumour may play a role, since best growth was seen in tumours of the caecum and terminal colon.