BIOLOGY OF METASTASIS AND ITS CLINICAL IMPLICATIONS - RENAL-CELL CANCER

The ability of malignant cells to metastasize from a primary tumor and from secondary lesions is the most life-threatening aspect of cancer. Reported factors enabling this metastatic cascade to occur include re duced levels or an absence of cell-adhesion molecules, prote olytic en zymes, and angiogenic factors. The metastatic cell must also escape im mune destruction. Defects in lymphocytes from renal-cell carcinoma pat ients with abnormalities in their proliferation, receptor structure, a nd signal transduction are present. The pathologic stage has been the most consistent single prognostic factor to influence survival. Other factors include the performance status, age, and histology grade and m ay include serum interleukin 6 (IL-6) levels and ploidy. Current and f uture therapeutic approaches that interfere with this metastatic casca de include applications of cytokines, antiadhesion-molecule strategies , and antisense nucleotides. An improvement in our understanding of th e biology of metastases is essential before a significant increase in the cure rate can be realized.