The comparison of Chinese women in terms of risk factors, genetics and treatment of endometriosis

Further research is required to clarify underlying mechanisms of endometriosis and to allow clinicians to diagnose women with endometriosis and to be able to manage them more effectively.

Key Points

Highlights:

• This article is a comparative overview of risk factors, genetics, and treatment of endometriosis in Chinese women. The effectiveness of the use of traditional Chinese medicine (TCM) in endometriosis has also been included.

Importance:

• Endometriosis is an important disease affecting 10-15% of women in reproductive age. It has significant effects on the quality of life and reproductive potential. Despite many several diagnostic methods, complete treatment is still not possible. A complete understanding of the underlying mechanisms would ensure that diagnostic approaches and treatment modalities are more effective.

What’s done here?

• This review evaluates the genetic basis, risk factors and management modalities of endometriosis comparing the Asian women with European-American women.
• The efficacy of traditional Chinese medicine (TCM) has also been compared with Western medicine.

Key results:

• Endometriosis defined as occurring of endometrial stroma and glands outside the uterus is an estrogen-dependent chronic disease and affects 10-15% of women during the child-bearing age.
• Several studies have shown that there is an association between endometriosis and ethnicity. When compared with European-American women endometriosis is encountered more often in Asian women and this is due to more frequent genetic polymorphism.
• Environmental factors such as exposure to elevated levels of phthalate esters, persistent organochlorine pollutants, perfluorochemicals, cigarette smoke could result in endometriosis by causing oxidative stress, altering hormonal levels, decreasing immunity.
• The most widely accepted theory is Sampson’s theory of retrograde menstruation that advocates the backward flow of menstrual blood through the fallopian tubes into the peritoneal cavity during menses. Other theories support the occurrence of coelomic metaplasia, bone marrow-derived stem cells, lymphatic and vascular dissemination.  
• Once endometriosis is established, women suffer from symptoms such as dysmenorrhea, chronic pelvic pain, dyspareunia, extragenital symptoms through inflammatory changes. Infertility is another major concern affecting 30-50% of the women affected by endometriosis. However, the asymptomatic occurrence in some patients with endometriosis leads to a delay in diagnosis up to 10 years.
• Endometriosis is surgically staged according to the revised American Society for Reproductive Medicine (rASRM) scoring system providing a standard approach regarding operative findings. However, there is no direct correlation between stage of endometriosis and severity of symptoms. Endometriosis Fertility Index (EFI) has been developed to predict postoperative pregnancy outcome and Chinese Medical Association (CMA) utilizes this scoring system for assessing the outcomes.
• CMA recommends the color Doppler ultrasound and CT/MRI as initial diagnostic imaging techniques. The gold standard method for the diagnosis of endometriosis is the histopathologic examination following laparoscopic surgery. Serum CA125 levels are elevated in these women, although it has low sensitivity and specificity for the accurate diagnosis of endometriosis.
• According to CMA guidelines, CA125 assessment is only useful for the detection of advanced stage endometriosis, endometriosis combined with adenomyosis or pelvic inflammation, and the diagnosis of endometrioma rupture.
• The aim of all treatment modalities is to alleviate symptoms of the diseases such as pelvic pain which decreases the quality of life of the patients and to improve fertility and decrease obstetric problems.
• CMA recommends the empirical treatment in the cases without obvious pelvic mass or infertility. Non-steroidal anti-inflammatory drugs, oral contraceptives, and progestins are indicated in women with endometriosis according to both CMA and ESHRE guidelines. They also recommend the continuous use of hormonal treatment postoperatively to keep endometriotic lesions under control.
• In the cases of deep infiltrating endometriosis, the combination of surgical excision and hormonal therapy is indicated by both CMA and ESHRE guidelines.
• All guidelines encourage alternative treatment strategies aiming to improve the quality of life, to reduce pain, recurrence and to decrease the need for multiple surgeries.
• Although traditional Chinese medicine (TCM) is widely used and considered effective in China, there is a need for further studies to evaluate its efficacy.
• Medically assisted reproduction techniques such as ovulation induction, stimulation, intrauterine insemination and assisted reproduction techniques are highly effective in the management of endometriosis-associated fertility problems according to many international guidelines including CMA.
• The assessment of the quality of life is important during the clinical evaluation and treatment efficacy in women with endometriosis. Several questionnaires such as Short-Form 36, Short-Form 12, Endometriosis Health Profile-30, Endometriosis Health Profile-5 have been used based on both CMA and other international guidelines.

Lay Summary

Endometriosis is characterized by endometrial implants outside of the uterine cavity. There is a wide spectrum of symptoms of this disease including dysmenorrhea, chronic pelvic pain, dyspareunia, extragenital symptoms. The pathogenesis of endometriosis appears to be multifactorial, including ectopic endometrial tissue, altered immunity, imbalanced cell proliferation and apoptosis, aberrant hormonal signaling, and genetic factors.

Dai et al, a group of scientists from Peking Union Medical College Hospital in China, published a review titled as “A review of the risk factors, genetics, and treatment of endometriosis in Chinese women: a comparative update” in the BMJ Reproductive Health.

Genetic predisposition and environmental factors contribute to the formation of endometriosis. Chinese women have a nine-fold increased risk for developing endometriosis due to mutations and polymorphisms in several genes. Chinese Medical Association (CMA) recommends the use of imaging techniques such as color Doppler ultrasound and CT/MRI for the initial diagnosis of endometriosis. However, CMA emphasizes the importance of histopathological evaluation for definitive diagnosis. Non-invasive methods including elevated serum CA125 levels cannot be used as a diagnostic marker. The women with endometriosis require long-term management due to its chronic inflammatory nature. Empirical and postoperative hormonal treatment is proven to be effective. CMA specifically recommends the surgical intervention to the patients with large endometriomas and infertility problems and who do not respond to hormonal therapy. In case of deep infiltrating endometriosis, surgical resection is strongly suggested. Traditional Chinese medicine (TCM) is preferred in Chinese women with endometriosis to control the postoperative recurrence, alleviate pain symptoms, and to improve the quality of life. 

The authors concluded that several gaps still remain despite much progress in the diagnosis and treatment of endometriosis.  

“Further researches should be required on non-invasive diagnostic methods and management options to improve patient outcomes” they added.

Research Source: https://www.ncbi.nlm.nih.gov/pubmed/29783992