Objective: To study the form and frequency of p16 gene deletion and point mutation in human breast neoplasm and the effective detection.
Methods: Cell culture was made using repeat-adhering method to purify human breast neoplasm cells and PCR-SSCP analysis in 14 highly purified fresh breast neoplasm, 14 fresh none-purified specimens, 27 paraffin-embedded specimens and corresponding normal tissues beside neoplasms.
Results: The rate of p16 gene deletion and point mutation was 42.9% (6/14) in the highly purified group, in which exon 1st - 3rd, showed homozygous deletion (5 cases) and exon 2nd showed mutation (1 case). The rate of p16 gene mutation in the other three groups was 7.1%, 7.4% and 4.9%. The detection rate of mutation was significantly higher in the highly purified group than in the other three groups (P < 0.01), but it was not significantly different in the other three groups (P > 0.05).
Conclusions: p16 gene deletion and point mutation exist in primary breast cancer. Homozygous deletion and small fragment deletion may be an important mechanism of inactivation in human breast neoplasm. Purified cancer cells will enhance the detection rate.