They also provide helpful information about prognosis and treatment.
• Flow cytometry. This technique analyzes a tumor's DNA content to find out whether the cancer cells contain the normal number of chromosomes (diploid) or an abnormal amount (aneuploid). Aneuploid tumors tend to be poorly differentiated and aggressive.
• S-phase testing. This technique measures how fast a tumor is growing. In the S-phase of a cell's growth cycle, new DNA is synthesized to prepare for the division of one cell into two. A tumor that is growing slowly may have less than 7 percent of cells in the S-phase. A rapidly growing tumor has 8 percent or more. Tumors with higher rates of growth have a poorer prognosis and may need more aggressive treatment.