Laparoscopic evaluation of the onset and progression of endometriosis

To clarify the pathogenesis of endometriosis on the basis of analysis of primary lesion sites, age at onset, rate of progression, and response to drug treatment.

The clinical records of 690 women with laparoscopically confirmed endometriosis were retrospectively analyzed based on the revised American Fertility Society point system.

The primary site of endometriosis was the uterosacral ligament and pelvic peritoneum/pouch of Douglas in 73% of patients with stage I disease, whereas only 16% had ovarian lesions. However, disease progression was associated with an increasing frequency of ovarian lesions. In terms of the revised American Fertility Society score, endometriosis progressed at a mean rate of 0.3 point per month. Thus the earliest onset of endometriosis was estimated at 3 to 4 years after menarche. Drug therapy improved the revised American Fertility Society score by about 50%. Patients with a low response to an initial cycle of therapy generally showed further improvement after an additional treatment cycle.

Because endometriosis may occur as early as 3 to 4 years after menarche and gradually progresses, drug therapy, including long-term treatment, should be carried out in women with definitive evidence of endometriosis who must maintain their reproductive potential.