Pathological findings in early-stage endometrial cancer.

Objective: The aim of this study was to assess the pathological characteristics of early-stage endometrial cancer, with regard to endometrioid versus serous papillary adenocarcinoma.

Methods: Sixty-six cases of early-stage endometrial carcinoma were classified into two groups: group I--36 cases of endometrioid endometrial cancer, staged IA-IB and graded G1-G2; group II--30 cases of Stage I serous papillary endometrial cancer. The pathological characteristics compared between the two groups included features such as tumor location in the uterine cavity, tumor focality, lymphovascular invasion, as well as the status of the uninvolved endometrium, adjacent to the tumor. Patient clinical characteristics were obtained from the medical records.

Results: Significantly more patients with endometrioid endometrial cancer were premenopausal (p < 0.0001), obese (p < 0.02), had hypertension (p < 0.00001) and familial cancer (p < 0.0001). On the other hand, significantly more patients with serous papillary cancer had another primary malignancy (p < 0.001). Considering the pathological characteristics, 75% of endometrioid as compared with 6.7% of serous papillary cancer cases were found in the upper uterine segment only (p < 0.0001). Multifocality was observed in 16.7% of endometrioid as compared with 100% of serous papillary cancer cases (p < 0.0001). Lymphovascular space invasion was absent in all cases of endometrioid cancer, while present in 90% of serous papillary cancer cases (p < 0.0001). Seventy-five percent of endometrioid and 100% of serous papillary cancer cases were associated with an atrophic endometrium.

Conclusion: The clinical and pathological features of early-stage endometrial cancer differ according to the histological type of the cancer. The majority of endometrioid cancers are probably associated with an atrophic or normally cycling endometrium, and not with endometrial hyperplasia.