Endometriosis, like most living things and vampires, needs blood to survive. Those patches of endometriosis that grow within people need a constant blood supply because they grow at an accelerated rate. If you look at this picture you can see a blackish endometriotic implant and lots of little blood vessels leading up to it like some sanguine road map. The tricky thing about endometriosis is that it can form its own blood supply, generating new blood vessels from existing ones, a process called angiogenesis. This is one of the reasons endometriosis is so persistent, it’s one of the same tricks tumours use to survive.
Of course knowing this means it may be possible to use drugs that inhibit angiogenesis to effectively ‘starve’ the endometriosis of its blood supply. This has been the focus of quite a bit of research over the last few years with some studies looking at drugs that inhibit the growth of new blood vessels as a possible new therapy for endometriosis. Actual data on human trails is hard to come by, but what has been done is quite positive. One study found that treating women with a combination of Goserelin (a GnRH analogue) and Thalidomide (yes, thalidomide) caused regression of ovarian endometriotic cysts in 8 out of 10 cases after a 6 month course of treatment. Now I will be the first to admit this is a very preliminary and quite small study and I do have some reservations about the design of the study, but the results are encouraging nevertheless.
Most other work testing angiogenesis inhibitors for endometriosis is done on animal models, usually mice or rats. The results of these studies has also been supportive of the use of angiogenesis inhibitors for the treatment of endometriosis, most recently there’s been a study published very recently that reported the use of a drug called Fenofibrate (drug that is normally used to treat liver disease and high cholesterol ) reduced the growth of endometriosis in rats.
This also illustrates a cause that I am very supportive of, using drugs that already exist for the treatment of other diseases as possible novel therapies for endometriosis. This has several advantages, for example if a drug is already being used to treat something else then we know it is safe to use on humans and we know the side effects (angiogenesis inhibitors are something you should definitely not take when pregnant for example). Drugs can often have effects that are unforeseen by their developers, sometimes these effects can be very negative (such as the case of Thalidomide) or sometime they can be positive (such as the case of Thalidomide).
If you would like to read more on angiogenesis inhibitors and endometriosis there is a page on the World Endometriosis Society website about this very subject.