We examined the DNA pattern, AgNOR number and PCNA-positive ratio (PCNA ratio) from biopsy specimens of oesophageal carcinoma, and attempted to identify any prognostic factors for oesophageal carcinoma. DNA analysis: the cell nuclear DNA content was measured and the distribution pattern of the DNA content was grouped into four types according to the ploidy pattern (n = 182). The survival rate of patients with high-ploidy tumours (type III and IV) was shorter than that for low-ploidy tumours (type II), (P < 0.05). AgNOR number (n = 99) and PCNA ratio (n = 41): the AgNOR number and PCNA ratio were measured from 100 cancer cells in each specimen. Both the high-AgNOR-number patients (> or = 5) and the high-PCNA-ratio patients (> or = 35) demonstrated poorer prognoses than the low-rate patients (P < 0.05). These results suggest that the DNA pattern, AgNOR number and PCNA ratio may thus reflect the proliferative activity of tumours and therefore also offer the possibility of interdependence among these three factors.