Prognostic status of p53 gene mutation in canine mammary carcinoma

Background: The p53 gene mutations have been associated with the development of human breast and canine mammary neoplasms; breast carcinoma patients with alterations of p53 gene are considered to have a poor prognosis. Mammary carcinoma represents the most common malignant tumor in female dogs. However, the prognostic significance of p53 gene mutation in the dog has been unclear. Study design: The alteration in exons 5-8 of p53 gene in 69 canine mammary carcinomas were investigated by PCR-SSCP with direct sequence analysis and statistically analyzed to compare with other clinicopathological parameters including age, neuter; tumor size, stage, histology, p53 expression, recurrence and death from carcinoma. Results: 12 out of 69 (17%) carcinomas showed p53 gene mutations. After a follow-up period of 30 months, multivariate regression analysis revealed that p53 gene mutation was only an independent risk factor for increased risk of the recurrence and death from mammary carcinoma. Conclusion: The p53 gene alterations might contribute to the prognostic status in canine mammary carcinomas, in a way comparable to that of human tumors.