Joint symptoms and other adverse effects of AIs (and a comparison)from SABCS

[Lani]

oint Symptoms and Other Adverse Effects of Aromatase Inhibitors


Zosia Chustecka

December 22, 2006 (San Antonio) — New details about adverse effects associated with aromatase inhibitors (AIs) were reported in several poster presentations during the San Antonio Breast Cancer (SABC) Symposium and were poured over by clinicians eager to learn more about these relatively new products. Three of these drugs have been launched in recent years — anastrozole (Arimidex, AstraZeneca), exemestane (Aromasin, Pfizer) and letrozole (Femara, Novartis) — for use as adjuvant therapy in postmenopausal women with hormone-receptor–positive breast cancer. With their action of blocking estrogen synthesis, they offer an alternative to what has been the standard therapy, the selective estrogen-receptor modifier (SERM) tamoxifen.

One of the presentations concluded that joint symptoms with AIs are more prevalent and more severe than what has previously been described in clinical trials. Katherine Drew, MD, and colleagues from the Herbert Irving Comprehensive Cancer Center at Columbia University, in New York, noted that large adjuvant trials reported in 2002–2004 found the incidence of musculoskeletal disorders was 20% to 30% and that nearly 5% of patients discontinued therapy because of toxic effects.

However, in a cross-sectional study of 200 patients attending the academic practice at Columbia University, they found that 47% reported AI-related joint pain and 44% reported AI-related joint stiffness.

About two thirds of the patients who reported joint symptoms said the symptoms were moderate to severe, with the most common sites affected being knees and hands. Just over half of these women (52%) took oral medications for symptom relief, including nonsteroidal anti-inflammatory drugs (NSAIDs) and acetaminophen (paracetamol), while 46% used nonpharmacological interventions (mainly exercise).

Within this sample, the risk of joint symptoms was independent of age and which AI was used or for how long, the researchers commented. It was, however, inversely associated with being overweight and prior tamoxifen therapy, and previous exposure to taxanes was the strongest predictor of AI-related joint symptoms. Patients who had received taxanes were 4 times more likely than others to develop joint pain and stiffness while taking AIs.

"Because the success of AI therapy depends on patients' ability to adhere to treatment recommendations, further studies of interventions that may alleviate these symptoms and improve quality of life are needed," Dr. Crew and colleagues concluded. In a neighboring poster, the same team reported some success with acupuncture for these joint symptoms. A single-group pilot study in 21 women showed improvements in pain and stiffness and a decrease in analgesic use.