Aromatase inhibitors are medications used to stop estrogen production in postmenopausal women to treat hormone-receptor-positive breast cancer. Hormone-receptor-positive means cancer cells grow in response to the hormones estrogen and/or progesterone.
Aromatase inhibitors work by blocking the enzyme aromatase, which turns the hormone androgen into small amounts of estrogen in the body, so that less estrogen is present in the body to stimulate the growth of hormone-receptor-positive breast cancer cells.
The most common side effect of all aromatase inhibitors is joint pain or stiffness. For some people the joint pain is mild or moderate but for others, the pain is severe enough to interfere with daily life.
Joint pain caused by aromatase inhibitors occurs most commonly in the fingers, wrists, shoulders, knees, and ankles, though it can affect any joint. Joint pain may start about two months after initiating treatment and peak at around the six-month mark, though the side effect can also develop up to two years after starting therapy.
Other problems caused by aromatase inhibitors may include:
- Heart problems
- Bone loss (osteoporosis)
- More broken bones than tamoxifen (Soltamox), at least during the first few years of treatment
What Are Examples of Aromatase Inhibitors?
There are three aromatase inhibitors:
Each medication is a pill, typically taken orally once daily. All are available as generic medicines.
What Are the Benefits of Aromatase Inhibitors?
After initial treatment which may include surgery and sometimes chemotherapy and radiation therapy, aromatase inhibitors are the best hormonal therapy to start with in treating early-stage, hormone-receptor-positive breast cancer, compared to tamoxifen.
- Switching to an aromatase inhibitor after taking tamoxifen for two to three years (for a total of five years of hormonal therapy) offers more benefits than five years of tamoxifen
- Taking an aromatase inhibitor for five years after taking tamoxifen for five years continues to reduce the risk of cancer recurrence, compared to no treatment after tamoxifen
How Do You Manage Joint Pain Caused by Aromatase Inhibitors?
There are several approaches to managing joint pain due to aromatase inhibitors, such as:
- Regular exercise keeps the muscles surrounding the joints strong and flexible, and can help protect against pain and injury
- Improves symptoms more than pain medication in the long term
- Suggested exercises include:
- Talk to your doctor before starting any exercise program
- Diet changes
- Weight loss
- Excess weight can put pressure on joints and weaken them over time
- Get enough calcium and vitamin D
- Calcium is essential for strong bones, and vitamin D helps the body absorb calcium
- Good dietary sources of calcium include leafy vegetables such as spinach or kale, fish such as sardines or salmon, some nuts, beans, and low-fat dairy products
- Good dietary sources of vitamin D include oily fish such as mackerel or herring, red meat, liver, egg yolks, and vitamin D fortified cereals
- Vitamin D supplements may also be recommended by your doctor
- Exposure to sunlight is another source of vitamin D, but too much sun exposure can lead to sunburn, premature skin aging, eye damage, heat exhaustion or heat stroke, and skin cancer. Talk to your doctor about how much sun exposure you may need and how to get exposure safely.
- Weight loss
- Pain medications
- May be useful if symptoms are mild to moderate
- Talk to your doctor about which medicine is right for you and the appropriate dosage
- Switching to another aromatase inhibitor
- Each medication is slightly different and switching medicines may help relieve joint pain issues