BACKGROUND: We examined the association of one linked GC/AT polymorphism at p73 
with the risk of colorectal cancer.
AIM: In this study, we investigated whether this polymorphism was related to the 
risk of colorectal cancer, and whether there were relationships between the 
polymorphism and loss of heterozygosity, protein expression, or 
clinicopathologic variables.
MATERIALS AND METHODS: The p73 genotypes were determined by polymerase chain 
reaction-restriction fragment length polymorphism in 150 Tunisian patients with 
colorectal cancer and in 204 healthy control subjects. Immunohistochemistry was 
performed on normal mucosa, primary tumor, and metastasis.
RESULTS: The frequencies of the genotypes were 52% for wild-type (GC/GC), 31% 
for heterozygotes (GC/AT), and 17% for variants(AT/AT) in patients, and 54%, 
35%, and 11% in controls, respectively. There were no significant differences of 
the frequencies of the 3 genotypes between the patients and controls (P=0.11). 
We did not find any relationship of the genotypes with clinicopathologic 
features of patients. We found that patients with the GC/GC genotype had a 
significantly more favorable clinical outcome than the patients with the AT 
variants (AT/AT or GC/AT genotype). There were no significant difference between 
tumoral immunostaining and p73 polymorphism (P=0.16) but we found that the 
samples carrying the AT allele showed a tendency to be more stained in tumor. No 
loss of heterozygosity was observed at p73 locus. Our results suggest that the 
AT/AT genotype is significantly associated with poor prognosis in colorectal 
cancer. All these findings suggest that p73 polymorphism analysis may provide 
useful prognostic information for colorectal cancer patients.