Expanding role of breast cytopathology as a risk predictor

The potential of identification of a malignancy-associated biomarker in breast cancer diagnosis and research: hTERT gene DNA methylation

BACKGROUND

DNA hypermethylation has been documented to be prominent at a CpG island rich region about 600 bp upstream the transcription start site of the hTERT gene using qualitative methylation specific PCR on DNA isolated from tumor cell lines. In order to assess the potential significance of this biomarker in breast cancer research and diagnosis, we explored if such findings are reproducible on surgically resected fresh breast tumor cells.

METHODS

Using quantitative pyrosequencing technology, we investigated and present methylation status of four CpG islands of this region in a cohort of 77 invasive breast carcinomas using normal breast tissue as controls.

RESULTS

Globally, a significant hypermethylation in tumor cells was observed in the four CpG islands as a sum, in comparison to methylation of the normal breast tissue. Individually, certain CpG islands displayed methylation greater than 50% in about 3/4 of the 77 breast cancers, but in none of the normal breast tissue. Our results highlight the value of DNA hypermethylation in the -600 bp region of the hTERT gene as a potential marker for breast cancer diagnosis.

CONCLUSIONS

We believe that integration of this novel, malignancy-associated molecular testing with morphology is of significant value in the accurate interpretation of small tumor sample size obtained via fine needle aspiration biopsy, ductal lavage, and nipple fluid aspirates both in clinical practice and in breast cancer research. Diagn. Cytopathol. 2016;44:670-675. © 2016 Wiley Periodicals, Inc.

Cytomorphology as a risk predictor: experience with fine needle aspiration biopsy, nipple fluid aspiration, and ductal lavage

Primary prevention of breast cancer requires identification and elimination of cancer-causing agents, which is an incredibly difficult task to follow. Secondary prevention involves screening individuals who are at increased risk for breast cancer in hopes that early intervention will affect survival. In the 1980s, chemoprevention received serious attention. This approach was aimed at reducing cancer risk by administration of natural or synthetic clinical compounds that prevent, reverse, or suppress carcinogenesis in individuals at increased risk for cancer. It was not until 1998, however, when the first report from the National Surgical Adjunct Breast and Bowel Project (Breast Cancer Prevention Trial BCPT; P-1) randomized clinical trial appeared in the literature supporting the hypothesis that breast can-cer can be prevented. This study showed that administration of tamoxifen reduced the risk for invasive and noninvasive breast cancer by almost 50% in all age groups. With the current availability of tamoxifen as a chemopreventive agent and with the increasing emphasis on early breast cancer detection and prevention, more women seek consultation to determine their risk for breast cancer. However, in the absence of any detectable breast lesion, clinically and mammographically, only a few women may volunteer to have their breasts sampled by surgical biopsy for risk assessment. Other non-surgical procedures include fine needle aspiration biopsy (FNAB), nipple aspirate fluid (NAF), and the recently introduced procedure, ductal lavage. These techniques may provide better alternatives. These minimally invasive procedures are capable of recruiting cellular material for cytomorphologic interpretation and biomarker studies.