Clinical-pathological characteristics and short-term follow-up associated with proliferation, apoptosis and angiogenesis in a prospective cohort of patients with colorectal tumours.

We investigate the clinical and pathological features related to variations in colorectal tumour apoptosis, proliferation and angiogenesis and the influence of the latter in short-term mortality (2 years); 551 tumour samples from a prospective cohort of patients with colorectal cancer were examined and tumour biology markers were determined as follows: percentage of apoptotic cells, by the terminal deoxynucleotidyl transferase (TdT) dUTP Nick-End Labeling technique; Ki-67 antigen, as a cell proliferation marker and density of microvessels (as a marker of angiogenesis). An increase in the percentage of cellular apoptosis is significantly related to the presence of poorly differentiated tumours, with vascular invasion (p < 0.001). The CD105 angiogenesis marker is not related to any clinical-pathological parameter except that of higher frequency in older patients (p = 0.03). Ki-67 is more frequently expressed in tumours with less nervous invasion (p = 0.05). Neither apoptosis nor angiogenesis present any significant association with short-term survival. The only marker clearly related to 2-year survival is Ki-67, which is shown to be a good prognostic factor in the multivariate analysis (hazard ratio = 0.49; 95% confidence interval = 0.27-0.90). Therefore, in a prospective cohort of colorectal cancer patients, only Ki-67 is a marker of good prognosis in short-term follow-up.