Gastric cancer in a high-risk area in Italy. Histopathologic patterns according to Lauren's classification

Two thousand five hundred forty cases (1628 males and 912 females) of primary gastric cancer (GC) histologically diagnosed in gastroscopic biopsy or resected specimens, occurring from 1973 to 1982 in a high risk area in Italy (Florence), were reviewed. According to Lauren's criteria, 1587 (62.5%) were classified as intestinal type, 624 (24.6%) as diffuse type and 329 (12.9%) as mixed unclassified. The intestinal type is more frequent in males and increases in both sexes with advancing age; conversely for the diffuse type. In the two 5-year periods (1973-1977 and 1978-1982) the intestinal type shows a reduction over time more evident in females than in males, in contrast to the increasing trend for the diffuse type. In males, the distribution of Lauren's histologic types is stable over time for resected specimens, whereas there is a significant reduction of intestinal type for biopsy specimens. In females, both for resected and biopsy specimens there is a reduction of the intestinal type and an increase of the diffuse type from the first to the second period. For a subgroup of 297 subjects two different specimens were available (gastroscopic biopsy and surgical); sensitivity and positive predictive value, for biopsy specimen as compared with the resected one, in the diagnosis for Lauren's histologic types were calculated. An excess of diagnoses in the mixed/unclassified category for biopsy material was evident (positive predictive value = 44.3%). However, for the two main histologic types, the biopsy appears a quite reliable indicator of the final diagnosis on surgical material (intestinal: ppv = 88.6%; Diffuse: ppv = 87.0%). The study supports the hypothesis that the reduction in GC mortality in the Province of Florence in recent years may be associated with a moderate reduction in the frequency of the intestinal type.