In a nutshell
This review analyzed a number of studies investigating the occurrence of joint pain (arthralgia) as a side effect caused by aromatase inhibitors (AI's) in patients with estrogen receptor-positive (ER+) breast cancer.
Some background
Aromatase is an enzyme that facilitates the production of the hormone estrogen. Estrogen promotes growth of cancer cells in ER+ breast cancer. AI's are a class of drugs that work by blocking the action of the enzyme aromatase, thus inhibiting estrogen production. This means that less estrogen is available to stimulate the growth of cancer cells. Examples of AI's include letrozole (femara), exemestane (aromasin), anastrozole (arimidex), and vorozole (rivizor).
Although AI's have been proven to improve survival of ER+ breast cancer patients, they have been associated with several side effects due to the reduced levels of estrogen hormone. Possible side effects of AI treatment include arthralgia (joint pain), arthritis (joint inflammation) and osteoporosis (reduction in the density of the bones making them prone to fractures). These side effects may increase the rate of treatment non-compliance (failure to complete treatment) in patients.
Methods & findings
A number of studies involving AI use were analyzed in this review. All studies confirmed improved survival rates in patients using AI's.
One study involving 200 women showed that 47% of AI users developed AI related arthralgia. Another study reviewed here compared the occurrence of arthralgia between three types of AI's: exemestane, anastrazole, and letrozole. No difference in the rate of arthralgia was noted between these patients.
In relation to treatment non-compliance, several studies showed that between 13% to 22% of patients discontinued AI treatment due to arthralgia.
The bottom line
In summary, although AI's improve survival rate in patients with ER+ breast cancer, a large number of patients fail to follow treatment due to arthralgia.
What’s next?
Consult with your physician on how to reduce AI related side effects.
Published By :
Annals of oncology
Date :
May 31, 2013
I started suffering from AI-induced arthralgia about a month after starting therapy. After one year, with my doctor’s guidance, I stopped the medication for 3 weeks to verify the correlation to the AI. It was a very clear answer, so much so that all pains went away for the weeks after I started the medicine (switched to Letrazole after Anastrozole) up again, then it came back even worse. Knowing it was reversible was consoling, but I wanted relief before I opted out of taking it altogether. I found acupuncture to be a remarkable solution. I highly recommend it to any suffering from this debilitating side-effect (I couldn’t dress myself, walk or exercise normally). Find a practitioner that works for you. I found mine at the Integrative Medicine center at Memorial Sloan – Matthew Weitzman and Jonathan Siman, in particular. I am indebted to them. I can now continue to comply with my doctor’s recommendation to take AIs.
Thank you so much for commenting and providing guidance to others. Kathleen