Prognostic factors in colorectal cancer.

Prognosis of patients after colorectal cancer resection is predominantly influenced by the extent of local tumour growth and the presence or absence of nodal or distant metastasis. However, many factors have been used to generate numerous classification systems, leading to some debate and confusion. The effects on survival of 7 clinical and pathological parameters were reviewed in 801 consecutive patients operated upon with locally curative intent for colorectal cancer over a ten-year period. Age less than 50 or more than 70 years, poor cellular differentiation, high mucous secretion by tumour cells and Dukes' staging were the parameters significantly correlated to poor overall survival (p<0.001 for each). The Cox's regression analysis identified the same parameters as independent prognostic factors. The value of age as a prognostic factor remains debatable, but the other three parameters must be considered when evaluating prognosis after curative surgery for colorectal cancer and when considering adjuvant therapy.