Background: Patients with ovarian cancer often report having symptoms for months before diagnosis, but such findings are subject to recall bias. The aim of this study was to provide an objective evaluation of symptoms that precede a diagnosis of ovarian cancer.
Methods: Medicare provider claims linked to records in the California Surveillance, Epidemiology, and End Results data base were utilized to extract diagnosis and procedure codes for 1985 women age 68 years or older who resided in California with ovarian cancer, 6024 elderly women with localized breast cancer, and 10,941 age-matched, Medicare-enrolled women without cancer. Prevalence of rates of symptom-related diagnoses and procedure codes in Medicare claims records were obtained during 3-month periods up to 36 months before diagnosis of ovarian cancer.
Results: From 1 month to 3 months before patients were diagnosed with ovarian cancer, the frequency and adjusted odds ratios (ORs) with 95% confidence intervals (95%CIs) for 4 "target symptom" code groups were: abdominal pain (frequency, 30.6%; OR, 6.0; 95%CI, 5.1-6.9), abdominal swelling (frequency, 16.5%; OR, 30.9; 95%CI, 21.4-44.8), gastrointestinal symptoms (frequency, 8.4%; OR, 2.3; 95%CI, 1.8-3.0), and pelvic pain (frequency, 5.4%; OR, 4.3; 95%CI, 2.8-6.7). The adjusted odds for abdominal swelling codes was elevated 10-12 months before diagnosis (OR, 2.4; 95%CI, 1.2-4.6) for abdominal pain codes 7-9 months before diagnosis (OR, 1.3; 95%CI, 1.1-1.7). Abdominal imaging (frequency, 7.0%; OR, 1.3; 95%CI, 1.0-1.7) and pelvic imaging/CA125 (frequency, 3.7%; OR, 2.4; 95%CI, 1.7-3.4) showed an elevated frequency and adjusted odds 4-6 months before diagnosis. Patients with claims codes for "target symptoms" 4-36 months before diagnosis were more likely to have abdominal imaging (61.1%) or gastrointestinal procedures (30.8%) than pelvic imaging/CA125 (25.3%).
Conclusions: Patients with ovarian cancer were more likely than patients with breast cancer and women in a cancer-free control group to have target symptom codes (particularly abdominal swelling and pain) > 6 months before diagnosis. The evaluation of women with unexplained "target symptoms" should include pelvic imaging and/or CA125.