Complex non atypical hyperplasia and the subsequent risk of carcinoma, atypia and hysterectomy during the following 9-14 years.

Background: The aim of this study was to evaluate the long-term risk of developing atypical hyperplasia/endometrial cancer or having a hysterectomy after being diagnosed with complex non-atypical hyperplasia (CH).

Methods: A historic cohort study of 114 women diagnosed with CH between January 1st 2000 and December 31st 2005. All patient records and pathologic reports were reviewed with complete follow up on all patients in the national pathologic database until September 1st 2014. Kaplan-Meier analysis was used to determine (1) no hysterectomy and (2) no diagnosis of endometrial cancer or atypia after the CH diagnosis.

Results: 15% (n = 17) were diagnosed with endometrial cancer and 7% (n = 8) with atypia, most during the first year (10 cancer, 7 atypia). 9% (8/85) of the remaining women at risk developed cancer or atypia in the follow-up period after one year. By Kaplan-Meier the five-year risk for cancer or atypia was 20% (CI; 14-21). The risk of having undergone hysterectomy within five years was 30% (CI; 22-39).

Conclusions: The long-term risk of being diagnosed with atypia or cancer after a CH diagnose is not insignificant, when disregarding patients having undergone hysterectomy. More than half the women with atypia or cancer are diagnosed or operated during the first year. This could indicate the presence of concomitant but unidentified cancer or atypia at the time of initial sampling. This study reinforces the importance of follow up or treatment of women with CH - especially, but not only during the first year. Conclusions: The risk of having a hysterectomy or diagnosed with atypical hyperplasia/cancer endometrie is high after a diagnosis of complex hyperplasia without atypia.