The Incidence of Colorectal Cancer Is Decreasing in the Older Age Cohorts in the Zaanstreek Region in the Netherlands: An Age-Cohort Effect

Table 1

Number of colorectal cancer in the different age cohorts in the consecutive years.

Age cohorts	31–40	41–50	51–60	61–70	71–80	81–90	>91
1990	—	4	1	6	13	6	—
1991	—	2	6	6	11	7	3
1992	2	3	4	13	20	11	1
1993	—	4	9	12	21	14	1
1994	—	2	12	8	21	9	1
1995	1	2	17	18	20	14	5
1996	2	2	9	11	16	10	—
1997	1	4	10	10	22	7	—
1998	1	5	10	16	29	11	1
1999	—	2	7	21	15	13	2
2000	1	2	8	20	25	10	1
2001	1	4	17	10	21	11	2
2002	—	6	10	24	21	14	—
2003	—	2	12	27	31	17	2
2004	—	4	20	28	28	16	1
2005	—	5	15	37	22	15	1
2006	1	6	20	30	34	16	—
2007	1	11	14	29	22	20	—
2008	—	1	9	30	31	17	1
2009	2	2	17	32	47	16	2
2010	3	9	16	40	36	24	3

In 1990, one patient of 28 years was diagnosed with colon cancer; in 1998 and 1999, two patients aged 26 and 30 years were diagnosed with cancer.