Amplification of the hst-1 gene was examined in 82 patients with oesophageal carcinoma by dot blot hybridization to assess the potential of haematogenous recurrence after curative resection. Intensity of amplification was considered negative (one- to twofold increase) in 45 patients, low (three-sixfold increase) in 19 and high (greater than sevenfold) in 18. Haematogenous recurrence after curative resection was found in seven of eight patients with high amplification and was significantly higher in such patients than in those without amplification (P < 0.05). The finding that sevenfold or greater amplification of the hst-1 gene seems to be associated with haematogenous recurrence of oesophageal cancer after resection may serve to assess the clinical outcome.