P&S Journal: Spring 1997, Vol.17, No.2
Earlier Detection of Prostate Cancer
Scientists at P&S have confirmed the validity of a gene associated with prostate cancer and its potential use as the basis for earlier detection and staging methods for the disease. The confirmation was published in the January issue of Cancer Research.
The new gene, known as PTI-1, was first identified in 1995 by principal investigator Dr. Paul B. Fisher, professor of clinical pathology in pathology and urology, and colleagues.
In this study, Dr. Fisher's research team found that PTI-1 can detect a single prostate cancer cell in 100 million normal cells, indicating that the gene is an extremely sensitive detector of prostate cancer. Analysis of RNA from 30 blood samples used in the study indicates PTI-1 is expressed in patients with prostate cancer that has spread outside the gland, but not in patients without prostate cancer or those whose cancer is confined to the prostate. The findings have important implications because current methods for detecting prostate cancer cannot easily differentiate between prostate cancers confined to the prostate gland and those with metastatic potential. Serum prostate-specific antigen (PSA) and RT-PCR of PSA determinations detect both malignant and benign prostate disease; physical examination may miss small or centrally located tumors; and sampling error in tissue biopsy may lead to erroneous benign diagnosis.
"Although further testing with a larger number of patient samples is clearly needed, these provocative results suggest that PTI-1 monitoring might prove beneficial in prostate cancer diagnosis and provide an extremely sensitive marker for prostate cancer progression," the authors wrote.
The technique used to find the PTI-1 gene is known as rapid expression cloning and may represent an important advance for attempts to identify oncogenes in a wide variety of human cancers. Columbia University has licensed the technology to GenQuest (Seattle and New York City), a genomics company formed to focus on the identification and characterization of cancer-related genes. A patent application has been filed for the PTI-1 gene.
The research was funded by the Association for the Cure of Cancer of the Prostate; the Samuel Waxman Cancer Foundation; and the Chernow Endowment, of which Dr. Fisher is the Chernow Research Scientist. Other members of the research team were Drs. Yilong Sun, Jian Lin, and Aaron E. Katz.