The detection rates for colorectal cancers were investigated in 4,127 first-time visits and a total of 2,293 revisits at the Nagano Cancer Center over the last 20 years.
The detection rate for colorectal cancers among first-time visits (7.0%) was significantly higher than those among total revisits (1.2%).
The proportion of colorectal cancers was seen to rise with increasing age, especially over 60 years.
The detection rate for colorectal cancers in the group with subjective symptoms or hereditary relationship among first-timers was higher than that in the group without these factors.
Over half of detected colorectal cancers were early cancers. The proportion of early colorectal cancers increased when examinees underwent endoscopic examination.
It is desirable that people at risk have an examination of the large intestine and that a good system of for endoscopic examination of the large intestine be set up to heighten the detection rate for early colorectal cancers.