What are the treatment guidelines for endometriosis in Canada?

Canadian Guidelines for Endometriosis Treatment

First-line treatment for endometriosis in Canada should be hormonal therapy, with progestin-only options showing superior efficacy and safety profiles for most patients. 1

Diagnosis

• Definitive diagnosis requires surgical visualization of lesions
• Clinical diagnosis can be supported by:
  • Characteristic symptoms (pelvic pain, dysmenorrhea, dyspareunia)
  • Physical examination findings
  • Imaging with transvaginal ultrasound or pelvic MRI

Treatment Algorithm

First-Line Treatments

1. Progestin-only contraception

   • Levonorgestrel-releasing IUD (LNG-IUD) 1
   • Norethindrone acetate (5-15 mg daily) 1, 2
     • Initial dosage: 5 mg daily for two weeks
     • Increase by 2.5 mg every two weeks until reaching 15 mg daily
     • Continue for 6-9 months or until breakthrough bleeding occurs 2
   • Depot medroxyprogesterone acetate 1
   • Dienogest 1

2. Combined hormonal contraceptives (CHCs)

   • Recommended in continuous regimen
   • Standard starting dose: 30-35 μg ethinyl estradiol with levonorgestrel or norgestimate 1
   • Lower doses of ethinyl estradiol are recommended to minimize potential increased stroke risk 3
   • Contraindicated in patients with:
     • Severe uncontrolled hypertension
     • Ongoing hepatic dysfunction
     • Complicated valvular heart disease
     • Migraines with aura or focal neurologic symptoms
     • Complications of diabetes
     • History of thromboembolism or thrombophilia 1

Second-Line Treatments

1. GnRH agonists

   • Consider when first-line therapies are ineffective or contraindicated 4
   • Bone mineral density loss is a concern with prolonged use 5

2. GnRH antagonists

   • Emerging treatment option showing promise in clinical development 5

Surgical Options

1. Laparoscopic excision/ablation of endometriotic lesions

   • Consider for patients with persistent symptoms despite medical therapy 1
   • Provides significant pain reduction during the first six months 1

2. Hysterectomy with removal of endometriotic lesions

   • Consider for patients who have completed childbearing and have severe symptoms unresponsive to other treatments 1
   • Important caveat: Approximately 25% of patients experience recurrent pelvic pain after hysterectomy, and 10% require additional surgery 1, 4

Management and Follow-up

• Evaluate treatment response after 3-6 months 1
• Long-term management is typically required due to the chronic nature of the disease 1
• Approximately 25-44% of patients experience recurrent pelvic pain within 12 months of discontinuing hormonal treatment 1
• Monitor for common side effects of hormonal therapy:
  • Amenorrhea (occurs in approximately 75% of patients on MPA)
  • Breakthrough bleeding
  • Weight gain
  • Mood changes 1
• Monitor blood pressure at follow-up visits for CHC users 1

Special Considerations

Fertility

• Suppressive medical therapy alone does not improve fertility rates 1
• Surgery for severe endometriosis can help fertility but may risk ovarian reserve 1
• For patients desiring pregnancy, surgical removal of lesions should be considered 4

Stroke Risk

• Endometriosis is associated with a 16% to 34% increased risk of stroke 3
• Patients with endometriosis are at higher risk of hypertension, elevated cholesterol, and inflammation 3
• Early identification and modification of vascular risk factors may reduce stroke risk 3
• For patients with specific stroke risk factors (age >35 years, tobacco use, hypertension, or migraine with aura), progestin-only or nonhormonal contraception is reasonable to prevent increased stroke risk associated with estrogen-containing contraception 3

Treatment Efficacy

• Hormonal treatments including combined oral contraceptives, progestins, and GnRH agonists lead to clinically significant pain reduction compared with placebo 4
• However, 11% to 19% of individuals with endometriosis have no pain reduction with hormonal medications 4
• The Society of Obstetricians and Gynaecologists of Canada recommends evaluating treatment response after 3-6 months 1

This evidence-based approach to endometriosis management aligns with Canadian guidelines and emphasizes the importance of personalized treatment based on symptom severity, fertility desires, and comorbidities for optimal patient outcomes.