Is there a link between age at diagnosis of endometriosis and disease severity? What does research suggest? In this article, I am reviewing a relevant paper by Comptour et al. (1), a prospective study with data collected between 2004 and 2012, aiming to identify a possible correlation between age at diagnosis and severity of endometriosis.

In this study, 964 patients between 21 and 50 years of age from one geographical region in France were included. All patients had a new, histological diagnosis of endometriosis (none of them had previously been diagnosed with the disease) that was managed laparoscopically. The authors recorded the demographical data of the patients, intensity of pain symptoms and quality of life before surgery, as well as the extent of the disease based on the revised American Fertility Society (rAFS) score and the number/size of deep endometriosis nodules. They, then, compared the results between different age groups (</= 25 years, 26-30, 31-35, 36-40, >40) looking for statistically significant differences between those groups. This study included patients from 9 different hospitals in the region (public as well as private, of which only one was a referral centre), making the results possibly more reflective of the general population.

An interesting finding is that older women had smaller or fewer nodules of deep endometriosis compared to younger patients. Pain levels were higher in younger women but there were no statistically significant differences between different age groups as regards the extent of endometriosis based on the rAFS score. Furthermore, the authors did not describe statistically significant differences in the quality of life between different age groups, nor a link between rAFS score and quality of life. Interestingly, patients younger than 25 years of age had lower rAFS score (although this difference did not reach statistical significance) and less adhesions compared to older patients. What is more, the authors did not find a link between the anatomic extent/severity of endometriosis (based on the aforementioned scored) and the reported pain or quality of life.

The authors suggest that their findings may strengthen the argument against endometriosis always being a disease with a progressive course over time. Indeed, we do not yet have clear answers as to whether endometriosis does progress as time goes by or not, as some evidence seems to suggest that it does (2), whereas other does not support this theory (3).

The limitations of this study, however, need to be acknowledged. Firstly, the data were collected between 2004 and 2012, a period of time when both diagnosis and management of endometriosis were much different to today. Furthermore, the assessment of the size of deep endometriosis nodules was based on the experienced surgeons’ impression, rather than other modalities that have proved to be efficient for this purpose, such as Magnetic Resonance Imaging (MRI). Moreover, the authors were obliged to use the rAFS score which, as we know, is not designed to accurately stage deep endometriosis and, indeed, is less fit for this purpose compared to other classification systems (4). It, also, does not correlate well with symptom severity (5). The authors did not include asymptomatic patients. But the most important limitation of this study, in my view, is its design. If one wishes to draw any conclusions as to whether endometriosis has a progressive course over time, one needs to design a study, whereby patients would have a first laparoscopy for diagnostic purposes only and, then, a second laparoscopy to assess for any possible progress. However, this would not be ethical to do.

Personally, I feel that the topic of a possible link between age at diagnosis of endometriosis and disease severity can be examined from 2 different standpoints. If one considers that having surgery at a younger age may mean a higher likelihood of severe symptoms, one may expect younger patients to have more severe/extensive disease (although the association between symptom severity and rAFS score is known to be poor). On the other hand, if one believes that endometriosis clearly has a progressive course, one would expect older patients to have larger/more deep endometriosis nodules. This paper did not confirm either of those thoughts, however, despite its limitations, the results reported are of importance . We, still in present day, need more high-quality evidence on the natural progress of the disease over time.

References:

1. Comptour A. et al., Endometriosis: Age at diagnosis and the severity of the disease, Journal of Gynecology Obstetrics and Human Reproduction, 53(5), May 2024
2. D’Hooghe TM, Bambra CS, Raeymaekers BM, Koninckx PR. Development of spontaneous endometriosis in baboons. Obstet Gynecol 1996;88:462–6. https:// doi.org/10.1016/0029-7844(96)00205-0.
3. (Hans) Evers JLH. Is adolescent endometriosis a progressive disease that needs to be diagnosed and treated? Hum Reprod 2013;28:2023. https://doi.org/10.1093/ humrep/det298.
4. Keckstein J, Saridogan E, Ulrich UA, Sillem M, Oppelt P, Schweppe KW, et al. The #Enzian classification: a comprehensive non-invasive and surgical description system for endometriosis. Acta Obstet Gynecol Scand 2021;100:1165–75. https:// doi.org/10.1111/aogs.14099.
5. Haas D, Shebl O, Shamiyeh A, Oppelt P. The rASRM score and the Enzian classification for endometriosis: their strengths and weaknesses. Acta Obstet Gynecol Scand. 2013 Jan;92(1):3-7. doi: 10.1111/aogs.12026. Epub 2012 Nov 5. PMID: 23061819.