Siriraj Medical Journal (Jan 2016)
Effect of Age on Performance Parameters of Screening and Diagnostic Mammography Examinations
Abstract
Objective: To assess the effect of age specific on performance parameters among screening and diagnostic mam- mography examinations. Methods: During 1 January 2006 to 31 December 2007, 22,278 screening mammography examinations (MG) and 13,435 diagnostic MG , were retrospectively reviewed. Patients with breast cancer were either confirmed by histopathology report, Siriraj cancer registry or follow-up post treatment up to 12 months, while the negative breast cancer were followed up for at least 12 months. Cancer detection rate (CDR), sensitivity, specificity, and positive predictive value (PPV) were analysed according to age group distribution. Results: Of the total 22,278 screening examinations, 43.1% and 56.9% were below and above 50 years old, respec- tively. Among 13,435 diagnostic examinations, 66.9% and 33.1% were below and above 50 years, respectively. The mean age was 50.8 for screening and 53.3 for diagnostic (S.D.=8.1,9.0, respectively). The CDR of screening and diagnostic was 4.6 and 49.6 per 1,000 examinations, respectively. The CDR, PPV and specificity of screening and diagnostic mammography examination increased with higher age with statistical significance (p<0.005). The sensitivity of the diagnostic MG also increased with age (p<0.05), but not in the screening group. Conclusion: Age is one of the most important risk factors of breast cancer and also in outcome of key parameters on mammography performance. The study showed that the CDR, PPV and specificity increase with age both in the screening and diagnostic group as in the literatures except for the sensitivity in screening was not related to increased age. Our study also supported that MG screening among women 40-49 years is suitable as there were high cancer rate in both screening and diagnosis in 40-49 years with high sensitivity and specificity.
