RESULTS
The study sample included 2180 patients: 72% had colon cancer, and 28%
had rectal cancer; 1375 (63%) were men, with a mean age of 67.8 years
(SD 10.9), and 6% of the sample had TNM stage IV.
After adjusting for other variables (sex, age, TNM stage, Charlson
comorbidity index and location of the tumor), colonoscopy or CT scanning
within a year prevents death in the next period of follow-up, while
chemotherapy at a specified moment increases the risk of death in the
next follow-up period. However, in the case of recurrence, having CT
scanning or chemotherapy increases the risk. In fact, having CT scanning
at a specified moment increases the risk of recurrence of the tumor in
the next year (OR=2.55, 95% confidence interval (CI) = 1.93 – 3.37,
p<0.0001), as does receiving chemotherapy (OR=2.07, 95% CI =
1.69 – 2.54, p<0.0001). Complications in a specified moment
were conditioned or influenced by having CT scanning, colonoscopy,
chemotherapy and/or radiotherapy in the previous follow-up moment,
increasing the risk of adverse events in all cases (OR=1.25, p=0.0028;
OR=1.13, p=0.0329; OR=1.20, p=0.0126; OR=1.31, p=0.0244, respectively).
In relation to health-related quality-of-life questionnaires and anxiety
and depression scales, undergoing CT scanning, colonoscopy or
radiotherapy within a period of follow-up yielded statistically
significantly increasing scores with respect to anxiety, that is, higher
anxiety levels in the next period. In relation to health-related quality
of life, as measured by the EORTC-Q30, CT scanning, colonoscopy,
chemotherapy and radiotherapy resulted in a statistically significant
decrease in the scores, while having radiotherapy in a specified moment
also decreased the quality of life of the patients, as measured by the
EuroQol-5d, at the same timepoint of follow-up (Table 1).