Objective: To investigate the plasma and peritoneal fluid (PF) concentrations of CA-125 and placental protein (PP14) in women with deeply infiltrating endometriosis.
Design: Plasma and PF were collected during 384 consecutive laparoscopies for pelvic pain or infertility.
Main outcome measure: The presence and extent of endometriosis were carefully assessed, including the area, depth of infiltration, and volume of subtle lesions, typical lesions, and endometriomas. The day of the menstrual cycle was ascertained by endometrial biopsy and/or basal body temperature charts.
Results: Peritoneal fluid concentrations were some 100 and 10 times higher than plasma concentrations for CA-125 and PP14, respectively. Cyclic variations of CA-125 concentrations were only found in women with endometriosis showing increased plasma concentrations at the end of the cycle and increased PF concentrations in the early follicular phase. Cyclic variations of PP14 concentrations were found in women with and without endometriosis both in plasma and PF showing increased concentrations in the late luteal and early follicular phases. In women with endometriosis the increased plasma concentrations of PP14 and CA-125 correlated with the presence and volume of endometriomas and of deeply infiltrating endometriosis. The increased concentrations in PF correlated only with the pelvic area of subtle endometriotic lesions. The diagnostic sensitivity and specificity of CA-125 for endometriosis were 25% and 87%, respectively, and for endometriomas and/or deeply infiltrating endometriosis 36% and 87%, respectively, for a cutoff concentration of 25 U/mL.
Conclusion: Superficial pelvic endometriosis secretes PP14 and CA-125 mainly toward the PF, whereas endometriomas and deeply infiltrating endometriosis secrete mainly toward the plasma. The increased plasma concentrations of CA-125 are most pronounced during the late luteal phase, and endometriomas and/or deeply infiltrating endometriosis can be detected with a sensitivity of 36% and a specificity of 87%.