Scientists have discovered that the most dangerous cancer of the uterine lining closely resembles the worst ovarian and breast cancers, providing the most telling evidence yet that cancer will increasingly be seen as a disease defined primarily by its genetic fingerprint rather than just by the organ where it originated.

The study of endometrial cancer — the cancer of the uterine lining — and another of acute myeloid leukemia, published simultaneously on Wednesday by Nature and The New England Journal of Medicine, are part of a sprawling, ambitious project by the National Institutes of Health to scrutinize DNA aberrations in common cancers.

Over the past year, as part of this project, researchers have reported striking genetic changes in breast, colon and lung cancers that link them to other cancers. One kind of breast cancer was closely related to ovarian cancer. Colon cancers often had a genetic change found in breast cancer. And about half of squamous cell lung cancers might be attacked by drugs being developed for other cancers.

The endometrial cancer and leukemia efforts alone involved more than 100 researchers who studied close to 400 endometrial tumors and 200 leukemias. Endometrial cancer is the most common gynecological cancer in American women and strikes nearly 50,000 of them a year, killing about 8,000. Acute myeloid leukemia, the most prevalent acute adult leukemia, is diagnosed in about 14,000 Americans a year and kills about 10,000.