Table 2 Studies on estrogen receptor (ER) and progesterone receptor (PGR), and their subtypes in eutopic endometrium during ovarian endometriosis^a

Lessey et al., 1989 [20]

PE, OE, DIE [CE (n = 25), EE (n = 12), EC (n = 9)]

IHC

No difference was observed in the ER and PGR levels between CE and EE, as well as, between EE and EC. Analysis between CE and EE was not done based on phases of menstrual cycle despite tissue samples were collected during both cycle phases. Fertility history was not provided.

Burney et al., 2007 [10]

PE, OE [CE (n = 16), EE (n = 21)]

Microarray qRTPCR

2.3-fold downregulation of PGR mRNA was observed in EE compared to CE. Analysis between CE and EE was not done based on phases of menstrual cycle despite tissue samples were collected during both phases of menstrual cycle. Fertility history was not provided.

Bukulmez et al., 2008 [21]

PE, OE [CE (n = 8), EE (n = 12), EC (n = 14)]

qRTPCR, IHC, WB

Lower ESR1:ESR2 mRNA ratio was observed in CE and EE than EC along with higher immunopositivity for ERβ

in EC. Lower PRA and PRB was observed in EC as compared to EE and CE. Analysis based on phases of menstrual cycle was not reported despite tissue samples were collected during both cycle phases. No information on stages of endometriosis and fertility history was provided.

Cavallini et al., 2011 [22]

OE [CE (n = 10), EE_EC (n = 10)]

qRTPCR, ELISA, IHC

Protein expression of ERα was higher in EE than CE and EC with similar expressions in mRNA profiles. Protein expression of ERβ was lower in EE than EC and CE. Higher PGR mRNA and immunopositivity was observedin EE than in EC. No data for stages of endometriosis, phases of menstrual cycle and fertility history was provided.

Huhtinen et al., 2012 [12]

PE, OE, DIE [CE (n = 15), EE (n = 37), EC (n = 41)]

qRTPCR

ESR1 mRNA expression was lower in both phases of menstrual cycle in EC than CE. ESR1 mRNA was found to be lower in secretory phase as compared to proliferative phase in EE. ESR2 mRNA was higher in EC (OE and DIE) than CE in both phases. No data for stages of endometriosis and fertility history was provided.