title: The time since last menstrual period is important as a clinical predictor for non-steroidal aromatase inhibitor-related arthralgia.
abstract: BACKGROUND
  The clinical predictors of aromatase inhibitor-related arthralgia (AIA), a drug-related adverse reaction of aromatase inhibitors (AIs), remain unclear.
  
  
  METHODS
  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).
  
  
  RESULTS
  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).
  
  
  CONCLUSIONS
  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.
authors: Department of Surgery, Higashitokushima National Hospital, 1-1, Ohmukaikita,Ootera, Itano, Tokushima, 779-0193, Japan.
authors: Miyuki
authors: M
authors: Kanematsu
authors: Masami
authors: M
authors: Morimoto
authors: Junko
authors: J
authors: Honda
authors: Taeko
authors: T
authors: Nagao
authors: Misako
authors: M
authors: Nakagawa
authors: Masako
authors: M
authors: Takahashi
authors: Akira
authors: A
authors: Tangoku
authors: Mitsunori
authors: M
authors: Sasa
mesh_terms: D000328:Adult; D000368:Aged; D000077384:Anastrozole; D018931:Antineoplastic Agents, Hormonal / Q000009:adverse effects*; D047072:Aromatase Inhibitors / Q000009:adverse effects*; D018771:Arthralgia / Q000139:chemically induced* / Q000453:epidemiology; D005260:Female; D006801:Humans; D015994:Incidence; D008593:Menopause; D008875:Middle Aged; D009570:Nitriles / Q000009:adverse effects; D011446:Prospective Studies; D013997:Time Factors; D014230:Triazoles / Q000009:adverse effects
chemical_list: D018931:Antineoplastic Agents, Hormonal; D047072:Aromatase Inhibitors; D009570:Nitriles; D014230:Triazoles; D000077384:Anastrozole