Increased prevalence of p53 overexpression from typical endometriosis to atypical endometriosis and ovarian cancer associated with endometriosis

Objective: To evaluate the expression of p53, c-erb-B-2, MIB1 and Bcl-2 in normal endometrium, endometriosis, atypical endometriosis and ovarian cancer associated with endometriosis, looking for immunohistochemical markers that may help determine endometriosis with premalignant potential. Study design: Between 1948 and 1999, 410 epithelial ovarian cancers and 521 cases of endometriosis were surgically treated at Fundacion Jimenez Diaz. Pathology reports and slides were reviewed. Four groups were defined: (1) endometriosis/cancer (n = 17); (2) atypical endometriosis (n = 6): (3) endometriosis (n = 17) (4) endometrium (n = 7). Tumors and controls were immunostained and evaluated for expression of p53, c-erb-B-2, MIB1 and Bcl-2. Statistical analysis was performed using Chi-square for linear trends, Fisher exact and Kruskal-Wallis tests. Results: Of the 410 cancers, 17 (4.1%) had associated endometriosis and of the 521 endometriosis, 6 (1.2%) had atypical changes. Fourteen Of 17 (82.4%) cancers associated with endometriosis and all atypical endometriosis had p53 overexpression. Only 2 of 17 (11.8%) endometriosis and none of the endometriums had Mutant p53 (P < 0.01). We found a trend towards increased expression of MIB1 (0.073) in the cancer and atypical endometriosis groups, and no differences in expression of Bcl-2 or c-erb-B-2. The sensitivity and specificity of p53 as a marker for the diagnosis of atypical endometriosis and cancer associated with endometriosis were 87% Cl 95% (73.2-100%) and 92% (80.6-100%), respectively. When comparing all groups, the mean positive p53 and MIB1 cell count was statistically significant (P = 0.01). Conclusions: Overexpression of p53 in atypical endometriosis and cancer associated with endometriosis is a common finding and may be used to identify endometriosis with premalignant potential. rights reserved. (C)2003 Elsevier Ireland Ltd. All rights reserved.