Chromosome I8Q loss and prognosis in colorectal cancer

A method of determining prognosis of a patient having a TNM stage II colorectal cancer, consisting of the steps of:

• determining the presence or absence of two or more polymorphic genetic markers on chromosomes 18q in tumor tissue of the patient;
• determining the presence or absence of said two or more polymorphic genetic markers on chromosome 18q in non-neoplastic tissue of the patient;
• a polymorphic marker which is absent in said tumor tissue but present in said non-neoplastic tissue, indicating a somatic loss of markers on chromosome 18q;
• and
• ascertaining a predicted survival rate for the patient by applying survival outcome data obtained from a population of patients consisting of TNM stage II colorectat cancer patients in which somatic loss of polymorphic markers on chromosome 18q has been measured and used to divide the population of patients into two groups, wherein those with a somatic loss of a polymorphic marker on chromosome 18q are in a first group and those with no somatic loss of a polymorphic on chromosome 18q are in a second group, wherein the survival rate of the first group is provided to the patient if the patient is determined to have a somatic loss of a polymorphic marker and the survival rate of the second group is provided to the patient if the patient is determined to have no somatic loss of a polymorphic marker.