A recent report suggests that haematogenous dissemination of breast cells
may be caused by fine needle aspiration to beast tumour
Hong Kong evaluated the impact of fine needle aspiration (FNA) on breast cell
shedding into peripheral blood. They applied reverse- transcriptase chain
reaction (RT-PCR) assay targeted, against cytokeratin 19 (CK19) cytokeratin 20
(CK20) and the ß-subunit of human chorionic gonadotropin (ß-hCG) messenger RNAs.
The sensitivity of this assay was based on the different degree of admix
of MCF-7 breast cancer cell line with HL-60 leukemic cell line. For blood
samples from 24 cases with benign breast disease and 20 cases with malignant
diseases, 5 mL of peripheral blood was drawn prior to and within 10 minutes
Total RNA was extracted from the peripheral blood
mononuclear cells. ß-actin was used to assess the quality of cRNA.
Reverse-transcriptase chain reaction products were run in ethidium bromide gel
and observed under ultraviolet. Reverse-transcriptase chain reaction products
for ß-human chorionic gonadotropin were digested with Sty 1 endonucleatase to
confirm the specificity.
Reverse transcriptase-chain reaction assay
sensitivity was 1 MCF-7 cell in 10 (to the power of 5) HL-60 cells for
cytokeratin 19 and cytokeratin 20, and 1 in 10 (to the power of 6) for B-hcg.
The 24 benign cases, none of the pre-fine needle aspiration samples proved
positive to CK-20 and B-hcg. Three cases were positive for CK19. Relative to the
20 malignant cases, one pre-FNA sample was positive for all three markers and
two other samples proved positive for CK19.
Following aspiration, three
of 21 benign cases and one of 17 malignant cases with pre-FNA-negative signals
became positive for CK19, and three of 19 malignant cases with pre-FNA-negative
signals were positive for CK20 and ß-hcg. Of six pre-FNA-positive cases, all
remained positive for the respective marker.