Role of Tumor Suppressor Gene in Cancer Studied
Two studies investigate p53 mutations in head and neck cancer and breast cancer
WEDNESDAY, Dec. 19 (HealthDay News) -- Mutations in the tumor-suppressor protein p53 (TP53) gene are associated with reduced survival in squamous-cell head and neck cancer, and TP53 mutations in the stroma of non-hereditary invasive breast tumors may lead to metastatic spread to lymph nodes, according to two studies published in the Dec. 20 issue of the New England Journal of Medicine.
M. Luana Poeta, M.D., of Johns Hopkins University in Baltimore, and colleagues followed 560 patients with squamous-cell head and neck carcinoma undergoing surgical treatment, analyzing tumor DNA to investigate the association between TP53 mutations and prognosis. The researchers found that TP53 gene mutations, particularly mutations that disrupted the structure of the TP53 protein, were associated with decreased survival.
In a second study, Attila Patocs, M.D., Ph.D., of the Genomic Medicine Institute in Cleveland, and colleagues analyzed TP53 mutations and loss of heterozygosity and allelic imbalance on DNA taken from tumor epithelial and stromal cells in 43 patients with hereditary breast cancer and 175 patients with sporadic breast cancer. The researchers found that stromal loss of heterozygosity and TP53 mutations in the stroma of sporadic breast cancers, but not in the neoplastic epithelium, were associated with regional lymph node metastases.
"The significant association between stromal TP53 mutations and nodal metastases in sporadic breast cancers suggests that such mutation-bearing stromal cells provide a favorable microenvironment for tumor spread," Patocs and colleagues conclude.