Cytological nuclear atypia classification can predict prognosis in patients with endometrial cancer

Endometrial cancer is one of the leading causes of malignancy in females. Nuclear findings are important for patients with cancer, and can provide valuable information to treating oncologists. We investigated whether nuclear findings were a useful prognostic factor in patients with endometrial cancer.

We investigated 71 cases of endometrial carcinoma with paired histology and cytology at Kurume University Hospital. We classified endometrial endometrioid adenocarcinoma (EEC) G1 and G2 as type I carcinomas, and uterine papillary serous carcinoma (UPSC), clear cell carcinoma (CC) and EEC G3 as type II carcinomas. For the establishment of the cytological nuclear atypia classification, we examined the following nuclear factors on the cytological smears: mitotic figures, prominent nucleoli, nuclear area and anisonucleosis.

There was a significant difference in mitotic figures (P < 0.001) and anisonucleosis (P = 0.026) in cytological smears between type I and type II carcinomas. Based on these findings, we categorized cytological nuclear atypia into three groups, nuclear atypia-1 (57.7%), nuclear atypia-2 (19.7%) and nuclear atypia-3 (22.5%), and this classification system correlated well with prognosis in patients with endometrial cancer (P < 0.001). Furthermore, this classification system was able to extract patients with a good prognosis from those with high-grade carcinomas, such as UPSC+CC+EEC G3, and patients with a poor prognosis from those with EEC G1.

Our system of cytological nuclear atypia classification based on endometrial cytology can predict patient prognosis. Cytological nuclear atypia classification and histological typing may be useful for the treatment and follow-up of patients with endometrial cancer, and should be routinely incorporated into cytological reports.