A non-invasive method for the diagnosis of adenocarcinoma or precursor lesions in a female subject and a kit for performing such diagnosis are provided. The method comprises the steps of (1) preparing epithelial cells of a sample of the subject obtained from a rinse of the uterine cavity and, optionally, the fallopian tubes, and (2) performing an analysis of the cells to determine an abnormality associated with ovarian or endometrial cancer, where the abnormality is indicative of adenocarcinoma or a precursor lesion.