Correlation of p53 Mutations in ThinPrep-Processed Fine Needle Breast Aspirates with Surgically Resected Breast Cancers

Abstract

Mutations of the p53 gene are one of the most common genetic changes found in cancer; their presence may be prognostic and even influence treatment for breast cancer. In this study, we investigated whether DNA could be extracted from the residual cells left in ThinPrep-processed breast fine-needle aspirates and whether p53 gene changes could be detected in the DNA. The results were then correlated with DNA extracted from the matched formalin-fixed, paraffin-embedded, surgically resected breast cancer when available. DNA was successfully extracted from 54 of 62 aspirates and all 31 surgical specimens. p53 gene mutations were detected in 10 of the 54 cytology specimens (18.5%) and consisted of base pair substitutions or deletions. Silent or intronic p53 changes were found in five additional aspirates. One of the aspirates had two gene alterations, resulting in a total of six gene changes. Five of these changes were located in introns 6 or 9 and the sixth was a silent (no amino acid change) change in exon 6. p53 Polymorphisms were detected in nine aspirates (16.3%) and were located in codon 47 (one aspirate), codon 72 (six aspirates), and codon 213 (two aspirates). All cases with surgical material available showed identical p53 mutations, alterations, and polymorphisms in the resected tumors compared with those detected in the corresponding aspirates. The results of this study show that DNA suitable for analysis of p53 gene sequence changes can be successfully extracted from ThinPrep-processed breast fine-needle aspirates, and that identical alterations are detected in both the cytology and surgical specimens.

BRAFV600E mutation analysis of liquid-based preparation–processed fine needle aspiration sample improves the diagnostic rate of papillary thyroid carcinoma

“…However, studies have reported that, if LBP is used, residual samples or floating cells preserved in preservation solution can be used as goodquality source materials for molecular tests; good-quality DNA has been successfully extracted from LBP samples stored for more than a year [23,24]. In our study, the longest sample storage period was 13 months; and there was no significant difference in the quality of DNA between this sample and samples stored for shorter periods.…”

p53 Alterations and Protein Accumulation in Benign Breast Tissue and Breast Cancer Risk: A Cohort Study

“…Future studies should be large (which would allow assessment of effect modification by factors, such as menopausal status), should assess both p53 immunopositivity and mutation status, and should use state-of-the-art methods for p53 mutation detection. Although the present report involved the use of paraffin-embedded breast tissue, the analyses described herein can also be done on tissue obtained from needle biopsies and on cells obtained from fine-needle aspirates of the breast, both of which are done increasingly commonly nowadays (42,(51)(52)(53). If confirmed, the findings reported here might facilitate the development of new approaches both to the detection of women at increased risk of breast cancer and to their clinical management [e.g., by enabling chemoprevention or therapy to restore p53 function (54) to be targeted to specific subgroups of women].…”

Assessment of Thin-Layer Breast Aspirates for Immunocytochemical Evaluation of HER2 Status

“…9 In addition, immunocytochemistry and molecular analysis have been successfully applied to TP processed specimens. 14,15 HER2 gene amplification in human breast cancers was first described by Slamon et al in 1987. 4 Overexpression of HER2 protein results from gene amplification and occurs in 20-30% of invasive human breast cancer.…”