AMSTERDAM--Innovative strategies for thwarting metastasis are now at the brink of clinical application, Lance Liotta, MD, of the National Cancer Institute, reported at the 9th NCI-EORTC Symposium on New Drugs in Cancer Therapy.
"Proteins that regulate invasion and metastasis and the process of invasion provide new cellular targets for prevention and new molecular targets for intervention," Dr. Liotta said.
The thinking behind the new approach is that current anticancer therapy often fails because it begins too late, after metastasis has already occurred. Instead, Dr. Liotta argued, the ideal moment to act would be during the window of opportunity between the time that the cells become hyperplastic and the time that they acquire the ability to invade and metastasize.
Analyzing Precursor Lesions
NCI pathologists Drs. Buck and Zhuang have developed a new laser capture technique for microdissecting and genetically analyzing precursor lesions, which enables them to determine which cells are most likely to become invasive.
Applying this method, they found that the same genetic locus was missing in 90% of invasive prostate carcinoma samples and in 70% of precursor PIN (prostatic intraepithelial neoplasia) lesions from the same patients. "This implicates a new suppressor gene to be identified at 8p21," he said.
The NCI team has also used the new microdissection technique together with X-chromosome inactivation analysis to prove that carcinoma in situ of the breast does develop into invasive carcinoma.