Surgery and outcome of alveolar echinococcosis of the liver: historical comparison of mass screening systems in Japan.

The prognosis of patients with alveolar echinococcosis of the liver (AEL) is excellent when the lesions were completely resected, suggesting the significance of mass screening systems. We investigated resectability and prognosis of the disease with historical comparison of screening systems. The patients were classified into three groups: Group A (n = 63) detected by the current screening system, enzyme-linked immunosorbent assay and ultrasonography, since December 1984; Group B (n = 39), detected by a serological screening system performed between 1974 and 1984; and Group C (n = 64), non-screened patients accidentally discovered. The lesions at an early stage were most frequently found in group A, and the complete resection was performed at 74.6% in A, 41.0% in B, and 18.8% in C (p < 0.0008). Five-year survival rate was 100% in A, 74.0% in B, and 69.5% in C, with a significant intergroup difference (p < 0.05). The current system facilitates early diagnosis of the disease, contributing to its resectability and to a better outcome.