Clinical Prognostic Variables Age . Many studies have reported poorer prognosis in patients of colorectal cancer who are less than 40 years old. Majority of these present with higher stages and are attributed to delayed diagnosis, higher histological grade and greater numbers of mucinous and signet ring cell tumors in the young. However, when stage-adjusted survival is analysed, there is no significant difference in relative prognosis for the younger age group. 9 Gender .
Many studies report more favorable prognosis for females as with other malignancies.
10 Obstruction and Perforation . Obstruction and perforation significantly worsen the survival and some studies claim them as important determinants of prognosis independent of Dukes stage. There are essentially no cures once free perforation into the peritoneal cavity occurs. 12 Location of the primary tumor . The five year survival for rectal cancers at or below the peritoneal reflection is lower than for those above the reflection and for colon cancers.