Human kallikrein 2 (hk2) mRNA in peripheral blood of patients with thyroid cancer: A novel molecular marker?

To elucidate whether hK2 mRNA can be detected in peripheral blood of patients with thyroid disease using reverse transcription polymerase chain reaction (RT-PCR). A nested RT-PCR protocol for the detection of hK2 mRNA was established, and blood samples of 72 patients with a history of thyroid cancer, 10 patients with current metastases of thyroid cancer, and 32 volunteers were tested. hK2-transcripts were significantly more often detected in patients with thyroid cancer (20/72=28%) than in the control group (2/32=6%, P = 0.03, chi-square analysis). This is the first study reporting on hK2 as a potential molecular marker for patients with thyroid cancer. We could demonstrate a correlation between diagnosis of thyroid cancer and the positive signal for hK2 in the RT-PCR assay. Future studies are necessary to prove the clinical value of hK2 as a molecular marker regarding recurrence and outcome.