Gastrointestinal cancers; Incidence; Prevalence; Primary and subsequent cancers; Synchronous and metachronous occurrence; Time and space distribution; Clinical stages

A total of 355,624 new gastrointestinal (GI) cancers were registered in 1976-2005 in the Czech Cancer Registry. Of these, there were 14,744 (4.1%) primary and 26,790 (7.5%) subsequent cases, of which all were GI multiple cancers (12.1% males and 11.1% females). The primary GI cancers were followed by 16,362 other neoplasms (60.7% males, 39.3% females); the subsequent GI cancers were preceded by 31,519 other neoplasms (55.8% males, 44.2% females). Double neoplasms were higher in females, and multiple cases were higher in males. The number of primary cases peaked in 1997, the number of subsequent cases increased until 2005. Almost half of the cases were registered in the age group of 50-69 years. The average interval between primary GI cancers and subsequent neoplasms was 6.1 years; the ratio of synchronous to metachronous cases was 1:3.6 in males and 1: 5 in females. The most frequent synchronous cases in males ...etc.