Diagnosis of familial breast cancer by multiplex PCR and clinical parameters

Objective

Mutation analysis of mtDNA and nDNA are helpful in the determination of developmental potential, early diagnosis and gene therapy for breast cancer. In our study, we optimized the multiplex PCR in AFPBT and compared the results with morphological and immunohistochemical parameters for detection of BRCA mutations and mtDNA4977 deletion in familial and nonfamilial breast cancers.

Methods

The multiplex PCR was conducted on DNA from 71 archive breast tissue samples and 13 blood samples. We compared different paraffin removal procedures and DNA extraction procedures in combination in order to optimize and compare the results of the multiplex PCR with morphological and immunohistochemical parameters for diagnosis of breast cancers.

Results

The highest proportion of successful gene amplifications was obtained with a DNA isolation procedure using proteinase K digestion with followed boiling. Three 5382insC mutations were identified from 16 archival familial patients (19%) and five mtDNA4977 deletions were detected from nine blood familial breast cancers by the multiplex PCR. The mtDNA4977 deletion was highly prevalent in peripheral blood (56%), but it was absent in the breast tissue of cancer cases. Furthermore, familial breast cancer tumors exhibited higher mitotic activity, higher polymorphism, lower necrosis, lower tubules, higher ER-negatives and PR-negatives and lower TP53-positives than nonfamilial cancers.

Conclusion

Our results demonstrate that DNA extracted by the simple boiling method with a microwave yielded higher proportions of successful gene amplifications than the DNA extraction kit. Furthermore, differences in successful gene amplification may be related to the size and number of the gene fragments amplified. Our analysis shows that testing of mtDNA4977 deletions and 5382insC in combination with morphological and immunohistochemical parameters may be an extremely effective and inexpensive tool in testing breast cancer patients aimed to identify individuals with high risk of familial breast cancers.