Purpose: Rates of progression of endometrial hyperplasia (EH) to endometrial cancer (EC) are highly variable. Among several prognostic markers, PTEN has been recommended by ESMO-ESGO-ESTRO to identify premalignant EH. However, its prognostic accuracy is unclear. Thus, we aimed to assess: (1) the association between PTEN loss in EH and risk of cancer, and (2) the prognostic accuracy of PTEN immunohistochemistry in EH.
Methods: Electronic databases were searched from their inception to June 2018. All studies assessing PTEN immunohistochemistry in EH and the presence of EC on subsequent hysterectomy were included. Odds ratio (OR), sensitivity, specificity, positive and negative predictive value (PPV and NPV), positive and negative likelihood ratio (LR + and LR-) and area under the curve (AUC) on SROC curves were calculated with subgroup analysis (short/long-term; atypical/non-atypical EH).
Results: Nine retrospective studies assessing 933 EH were included. PTEN loss in EH was significantly associated with increased risk of EC (OR = 3.32, p = 0.001). The association was significant only on the short term ( < 1 year) (OR = 3.45, p = 0.002) and in atypical EH (OR = 1.89, p = 0.01). For overall analysis and short-term/atypical EH subgroup the prognostic accuracy was low, with sensitivity = 0.58 and 0.68, specificity = 0.60 and 0.48, VPp = 0.41 and 0.54, VPN = 0.75 and 0.63, LR + = 1.80 and 1.37, LR - = 0.62 and 0.56, AUC = 0.687 and 0.721, respectively.
Conclusion: PTEN loss in EH is a risk factor for EC, but is not reliable in predicting the risk of EC. In atypical EH, PTEN loss is associated with a risk of concurrent EC of over 50%. This information might integrate the patients' informed consent for the choice of treatment (conservative/hysterectomy), especially in borderline cases. In conservative approach, PTEN loss might suggest closer follow-up.
Keywords: EIN; Endometrial intraepithelial neoplasia; Endometrioid adenocarcinoma; Immunohistochemical; Prognosis; Tensin homolog; Tumor suppressor protein phosphatase.