According to the American Cancer Society, prostate cancer claims approximately 27,000 of us each year, the vast majority of our deaths are a result of recurrent metastatic disease. Metastatic prostate cancer occurs when tumor cells spread to other locations in the body and start to grow.
Currently, when you start Chemotherapy the only way to know if you are responding to the treatment is to use CT Scans which evaluate disease and tumor progression. Results of these scans can take 8 to 12 weeks before your oncologist can evaluate if your disease has progressed. PSA results, especially with advanced disease, are not reliable.
Immunicon Corporation today announced that the FDA has cleared the CellSearch(TM) Circulating Tumor Cell (CTC) Kit as an aid in the monitoring of patients with metastatic prostate cancer.
A sample of the blood is processed with the Kit, which counts tumor cells that are circulating in the blood stream (CTCs). Patients with 5 or more CTCs at baseline and at 3-4 weeks after the initiation of chemotherapy have significantly shorter overall survival times and faster disease progression than patients with less than 5 CTCs. The presence of CTCs at any time during the course of the disease is a strong independent predictor of future disease progression.
The CellSearch CTC kit was originally cleared in January 2004 to predict progression-free and overall survival in patients with metastatic breast cancer and later expanded to include monitoring. In November 2007, the kit was cleared by the FDA for monitoring metastatic colorectal cancer.
Byron D. Hewett, CEO and President of Immunicon Corporation, commented, “Because the three pivotal trials demonstrated that the CellSearch test predicts survival in prostate, breast and colorectal cancers, circulating tumor cell testing should become standard of care in the management of patients with metastatic disease. More importantly, oncologists can use the results to make better informed treatment decisions and improve patient care for three of the top carcinomas.”
In cases where CTC and PSA change were discordant, CTC change provided the most accurate assessment of prognosis.
Joel T Nowak MA, MSW
I wonder if the test called uPM3 could indicate if cancer is progressing?
It is an expensive test like around 500.00 in Canada (PSA test cost 8.00 in Canada)it could be a very usefull tool into understanding progression of the cancer.
L, Chypre C.
Université Laval, Québec, Québec, Canada.
OBJECTIVES: To evaluate, in a multicenter study, the diagnostic performance of a new molecular test uPM3 for detecting prostate cancer cells in urine because of the need for better methods to identify patients at risk of prostate cancer. METHODS: The uPM3 test is a nucleic acid amplification assay detecting simultaneously in the urine the relative expression of prostate-specific antigen (PSA) mRNA as a marker of prostate cells and PCA3RNA, which is selectively expressed in most types of prostate cancer. The test is performed using the isothermic nucleic acid-based amplification method, and the two targets are simultaneously detected in real-time fluorescence using specific beacons as probes in a thermostated spectrofluorometer. The test was performed on the first voided urine obtained after careful digital rectal examination of the prostate in men undergoing transrectal ultrasound-guided prostate biopsy. RESULTS: Of 517 patients undergoing biopsy at five centers, 443 (86%) had an assessable sample. Of those, 21%, 55%, and 24% had a total PSA level of less than 4 ng/mL, between 4 and 10 ng/mL, and greater than 10 ng/mL. The corresponding percentage of biopsies positive for cancer in these three groups was 20%, 35%, and 44%. The overall uPM3 sensitivity and specificity was 66% and 89%, respectively. In men with a PSA level less than 4 ng/mL, the sensitivity was 74% and specificity 91%. In those with a PSA level of 4 to 10 ng/mL, the sensitivity was 58% and specificity 91%. In those with a PSA level greater than 10 ng/mL, the sensitivity and specificity was 79% and 80%, respectively. The positive predictive value of uPM3 was 75% compared with 38% for total PSA, and the negative predictive value was 84% compared with 89% and 80% for a PSA cutoff of 2.5 and 4.0 ng/mL, respectively. The overall accuracy was 81% compared with 43% and 47% for total PSA at a cutoff of 2.5 and 4.0 ng/mL, respectively. CONCLUSIONS: These results suggest that the uPM3 molecular urine test may be an important adjunct to current methods for the detection of early prostate cancer.
PMID: 15302485 [PubMed – indexed for MEDLINE]