Objective: To evaluate the detailed clinicopathologic characteristics of parametrial spread in uterine endometrial cancer.
Methods: We retrospectively identified 334 individuals with uterine endometrial cancer who had undergone radical hysterectomy between 1988 and 2007. Parametrial spread was determined by histopathological analysis of surgically resected specimens.
Results: Twenty-eight (8.4%) individuals had histopathologically confirmed parametrial spread, and lymphatic or blood vessel invasion (22 cases) was the most frequently observed type of parametrial spread; direct invasion to parametrial connective tissue (five cases) or cardinal lymph node metastasis (four cases) were less frequently observed. Parametrial spread occurred not only in individuals with cervical involvement but also in individuals with more than half myometrial invasion, retroperitoneal (pelvic, paraaortic, or both), lymph node metastasis, ovarian metastasis, positive peritoneal cytology results, and lymphovascular space invasion. Twenty-six individuals (92.9%) with parametrial spread showed more than one of these histopathological factors (median number of factors 3, range 1-6); the other two individuals had lymphovascular space invasion alone. In 10 individuals with parametrial spread (35.7%), the condition recurred during the median follow-up period of 49 months, and initial recurrence was observed in the lung in six individuals (60.0%). Although the long-term prognosis for those with parametrial spread was significantly poorer than that of those without parametrial spread, both among all individuals (P<.001) and among individuals with International Federation of Gynecology and Obstetrics stage III (P<.05), multivariate analysis showed that parametrial spread was not an independent prognostic factor for uterine endometrial cancer.
Conclusion: Parametrial spread cannot be predicted by cervical involvement alone but may be predicted by various lymphovascular space invasion-related histopathologic factors. Further, parametrial spread may not be an independent prognostic factor in individuals with uterine endometrial cancer.
Level of evidence: III.