Table 2

Demographic data for the populations of multiple and single primary cancers

Group	No of patients	Median (range) age (y) at diagnosis of first colorectal cancer	Colorectal tumour site (% right sided)
Group 1 (comparison group)	444	69.5 (27–91)	26
Group 2 (study group)	128	69.0 (33–93)	44^3-151
Group 2cr	49	68.5 (35–90)	62^3-150 ^3-151
Group 2st	40	73.0 (50–93)	34
Group 2ov	31	64.5 (33–92)	35
Group 2en	28	68.0 (44–91)	30
Group 2ur	5	68.0 (42–82)	40
Group 2sb	3	71.0 (69–83)	50

↵3-150 This percentage includes 10 (19%) patients with synchronous cancers of both the left and right sides of the large bowel.
↵3-151 Significant increase compared with the single primary group.