Gail Model Underestimates Breast Cancer Risk in Thai Population

Abstract

Background: The Gail model is the most widely used method for breast cancer risk estimation. This model has<br />been studied and verified for its validity in many groups but there has yet to be a study to validate the Gail model in a<br />Thai population. This study aims to evaluate whether the Gail model can accurately calculate the risk of breast cancer<br />among Thai women. Methods: The subjects were recruited from the Division of Head, Neck, and Breast Surgery,<br />Department of Surgery, Siriraj Hospital. The patients attending the division were asked to enroll in the study and<br />complete questionnaires. Gail model scores were then calculated. Relationships between parameters were examined<br />using the Pearson's chi-square test, Fisher's exact test, and independent-samples t-test. Results: There were 514<br />women recruited. Age, parity, age at first-live birth, and history of atypical ductal hyperplasia (ADH) were significant<br />risk factors for breast cancer. The 5-year and lifetime risk score for breast cancer calculated by the Gail model were<br />not significantly different between the patient and the control subjects. The proportions of the subjects with lifetime<br />risk ≥20% were significantly higher in breast cancer patients (p=0.049). Conclusion: The Gail model underestimated<br />the risk of breast cancer in Thai women. Calibration of the model is still required before adoption in Thai population.