Prognostic significance of non-gastric malignancy after treatment of early gastric cancer

Abstract

The recurrence rate of early gastric cancer is low and so second malignancies developing after treatment of this cancer have potential prognostic significance. Some 633 patients with early gastric cancer were studied. The median observation time was 123 months. To examine the characteristics of patients with early gastric cancer and subsequent malignancy, two groups of patients, those with and those without non-gastric malignancy, were compared using univariate analysis with respect to various clinicopathological factors. To determine which parameters were independently significant, computer-based multivariate discriminant function analysis was applied. To estimate the prognostic significance of non-gastric malignancy, death rates from these diseases in patients treated for early gastric cancer were compared with the mortality rates attributable to the same diseases in the general population of Japan. The frequency of other malignancies, 9.6 per cent (61 of 633), was significantly higher than those gastric cancer recurrence rate of 2.4 per cent (15 of 633). After treatment for early gastric cancer patients with subsequent non-gastric malignancy had a significantly poorer outcome than those free from other cancers. Lung cancers were the major neoplasms occurring after the treatment of early gastric cancer. Univariate and multivariate analysis revealed male sex to be an independent risk factor for the subsequent development of non-gastric malignancy. Comparison of mortality rates revealed that men with early gastric cancer have a higher risk of death from non-gastric malignancy than the general male population. These results suggest that systemic surveillance is particularly important for male patients after the treatment of early gastric cancer.