A recently discovered genetic mechanism appears to play an important role in the development of cancer, scientists are reporting today in findings that may eventually lead to new ways to diagnose and treat the disease.The discoveries “change the landscape in cancer genetics,” Dr. Paul S. Meltzer of the National Human Genome Research Institute wrote in a commentary in the journal Nature, which is publishing three papers on the findings. Other scientists cautioned that the new findings merely add detail to the already complex picture of how tumors arise and grow.