Role of P-53 Gene in Preventing Breast Cancer

Abstract

Aurelian Udristioiu, Manole Cojocaru

Breast cancer affects more than one million patients annually in the world and is a leading cause of mortality. Histological type, grade, tumor size, lymph node involvement, and estrogen receptor and HER-2 receptor status, all influence prognosis and the probability of response to systemic therapies. P53 gene is mutated in about 30% of breast cancers/.The possible links between alterations of p53 and clinical or pathological features of breast tumors have been widely investigated. The first study to examine gene-expression patterns of breast cancer suggested that at least four major molecular classes of breast cancer exist: luminal-like, basal-like, normal like, and HER-2 positive.

Basal-like breast cancer account for 15% of breast cancers and are often described as triple negative breast cancers (TNBCs). In fact, TNBCs, defined by lack of expression of estrogen receptor, progesterone receptor, and HER2, probably include both basal-like breast cancers and some poorly differentiated luminal breast cancers. They are also associated with a younger age and a poor prognosis. TNBCs also have an increased frequency of TP53 mutations. Recently, it was shown that mutant p53 status was a strongly unfavorable prognostic factor for relapse-free survival and overall survival only in a triple negative group in patients treated with adjuvant anthracycline-containing chemotherapy.

Inflammatory breast cancer (IBC) is a clinical diagnosis known as the T4d category in the TNM classification. It is a distinct clinical subtype of locally advanced breast cancer (LABC), with a particularly aggressive behavior and poor prognosis. TP53 mutations are more frequent in inflammatory breast cancer (50%) than in non-inflammatory breast cancer (20–30%).

The results from these studies served as the justification for attempts to vaccinate patients using p53-derived peptides, and a number of clinical trials are in progress. The most advanced work used a long synthetic peptide mixture derived from p53 (p53-SLP; Netherlands).The vaccine is delivered in the adjuvant setting and induces T helper type I response in the majority of patients. However, the response may not be potent enough to result in clinical benefit as a mono-therapy because most patients had T-helper cells that failed to produce key cytokines, indicating that this treatment should also be associated with another type of conventional or immunotherapy therapy.

PDF