[Greater sensitivity of the PCR-SSCP technique compared with immunohistochemistry for the detection of exon 5 and 6 mutations of gene 53 in breast cancer].

BACKGROUND

p53 mutations constitute the most frequent genetic abnormality observed in breast cancer. The molecular study of p53 mutations not only provides prognostic information but also allows a better understanding of tumor biology. Most of the studies on p53 have been done by immunohistochemistry procedures. In this study we compare the sensitivity of immunohistochemistry and molecular genetics methods for the detection of p53 mutations.

PATIENTS AND METHODS

Forty tumors obtained from breast cancer patients that underwent modified radical mastectomy were analyzed for p53 mutations at exons 5 to 6 through PCR-single stranted conformational polymorphism (SSCP)-sequencing. Moreover, the tumor expression of p53 protein was analyzed by means of immunohistochemistry.

RESULTS

All tumors could be amplified by PCR and analyzed by the SSCP technique. Six tumors (15%) showed and altered electrophoretic mobility. In these cases a mutation was confirmed by gene sequencing. On the other hand, only two of these six tumors were positive in the immunohistochemical analysis.

CONCLUSIONS

The results confirm the utility of the PCR-SSCP technique for detection of p53 mutations and suggest to be more sensitive than immunohistochemistry.