The time since last menstrual period is important as a clinical predictor for non-steroidal aromatase inhibitor-related arthralgia
1 Department of Surgery, Higashitokushima National Hospital, 1-1, Ohmukai-kita, Ootera, Itano, Tokushima, 779-0193, Japan
2 Department of Oncological and Regenerative Surgery, Institute of Health Biosciences, The University of Tokushima, 3-18-15, Kuramoto-Cho, Tokushima, 770-8509, Japan
3 Department of Surgery, Tokushima Breast Care Clinic, 4-7-7, Nakashimada-Cho, Tokushima, 770-0052, Japan
BMC Cancer 2011, 11:436 doi:10.1186/1471-2407-11-436Published: 10 October 2011
The clinical predictors of aromatase inhibitor-related arthralgia (AIA), a drug-related adverse reaction of aromatase inhibitors (AIs), remain unclear.
AIA was prospectively surveyed every 4 months in 328 postmenopausal breast cancer patients administered a non-steroidal AI (anastrozole). Various clinicopathological parameters were recorded and analyzed (chi-square test, Fisher's exact test and logistic regression analysis).
The mean observation period was 39.9 months. AIA manifested in 114 patients (34.8%), with peaks of onset at 4 (33.7%) and 8 months (11.4%) after starting AI administration. Some cases manifested even after 13 months. AIA tended to occur in younger patients (incidences of 46.3%, 37.4% and 28.0% for ages of < 55, 55-65 and > 65 years, respectively (p = 0.063)) and decreased significantly with the age at menarche (53.3%, 35.3% and 15.4% for < 12, 12-15 and > 15 years, respectively (p = 0.036)). The incidences were 45.1%, 46.3 and 25.1% for the time since the last menstrual period (LMP) < 5 years, 5-10 years and > 10 years, being significantly lower at > 10 years (p < 0.001). In logistic regression analysis, the AIA incidence was significantly lower in the time since LMP > 10-year group versus the < 5-year group (odds ratio 0.44, p = 0.002), but the age at menarche showed no association. AIA manifested significantly earlier (≤ 6 months) as the time since LMP became shorter (< 5 years).
AIA tends to manifest early after starting AI, but some cases show delayed onset. The incidence was significantly lower in patients with a duration of > 10 years since LMP. When the time since LMP was short, the onset of AIA was significantly earlier after starting AI administration.