title: Does Metformin affect ER, PR, IGF-1R, β-catenin and PAX-2 expression in women with diabetes mellitus and endometrial cancer?
abstract: OBJECTIVE
  Diabetes mellitus, as a risk factor for endometrial cancer (EC), causes an increase in insulin and IGF-1 concentrations in the blood serum. The increase in insulin and IGF-1 are considered mitogenic factors contributory to cancer development. Studies suggest that metformin has preventive activity, decreasing mortality and the risk of neoplasms. Since estrogen (ER), progesterone (PR) and IGF-1 (IGF-1R) receptor expression and β-catenin and PAX-2 mutations are significant in the development of endometrial cancer, it was decided to study these factors in patients with endometrial cancer and type 2 diabetes mellitus (DM2), and to establish the effects of metformin on their expression.
  
  
  METHODS
  The expression of ER, PR, IGF-1R, β-catenin and PAX-2 have been immunohistochemically investigated in 86 type I endometrial cancer specimens. Patients were grouped according to the presence of DM2 and the type of hypoglycemic treatment administered.
  
  
  RESULTS
  Comparing EC patients with DM2 and normal glycemic status, we found increased IGF-1R expression in women with DM2. A decrease in ER expression was noted in women with EC and DM2 receiving metformin as compared to women treated with insulin (p = 0.004). There was no statistically significant difference in PR, IGF-1R, β-catenin and PAX-2 expression among women receiving metformin and other hypoglycemic treatment.
  
  
  CONCLUSIONS
  Although epidemiological studies suggest the beneficial role of metformin in many human cancers, there are still few studies confirming its favorable effect on endometrial cancer. Decreased ER expression in patients receiving metformin needs further research to allow evaluation of its clinical significance.
authors.forename: Anna
authors.initials: A
authors.lastname: Markowska
authors.affiliation: Gynecological Oncology Department, Poznań University of Medical Sciences, Szamarzewskiego 82/84, 60-569 Poznań, Poland. monika@pawalowska.pl.
authors.forename: Monika
authors.initials: M
authors.lastname: Pawałowska
authors.forename: Violetta
authors.initials: V
authors.lastname: Filas
authors.forename: Konstanty
authors.initials: K
authors.lastname: Korski
authors.forename: Marian
authors.initials: M
authors.lastname: Gryboś
authors.forename: Stefan
authors.initials: S
authors.lastname: Sajdak
authors.forename: Anita
authors.initials: A
authors.lastname: Olejek
authors.forename: Wiesława
authors.initials: W
authors.lastname: Bednarek
authors.forename: Beata
authors.initials: B
authors.lastname: Spiewankiewicz
authors.forename: Jolanta
authors.initials: J
authors.lastname: Lubin
authors.forename: Janina
authors.initials: J
authors.lastname: Markowska