Estimate your personal Gail-45 Breast Cancer Risk Score.
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Your GAIL Risk Score will appear here.
Understanding the GAIL Risk Calculator
The GAIL Risk Calculator (also known as the Tyrer-Cuzick model or IBIS model for certain variations) is a widely used tool to estimate a woman's lifetime and 5-year risk of developing invasive breast cancer. It's a crucial instrument for healthcare providers to identify women who might benefit from increased screening, preventative medications, or genetic counseling.
How it Works: The Underlying Factors
The calculator takes into account several significant risk factors, assigning a 'weight' or contribution to each. The exact calculation is complex and involves a statistical model, but the key inputs are:
Age: Breast cancer risk increases with age.
Number of First-Degree Relatives with Breast Cancer: Having a mother, sister, or daughter diagnosed with breast cancer significantly elevates risk.
Personal History of Breast Biopsy: Certain biopsy results can indicate a higher predisposition.
History of Atypical Hyperplasia: This is a specific type of benign breast condition found on biopsy that is associated with increased risk.
Number of Breast Biopsies: More biopsies might correlate with underlying factors increasing risk.
Personal History of Breast Cancer: A prior diagnosis of breast cancer increases the risk of a new primary cancer.
Age at First Radiation Therapy: Chest radiation therapy, often used for conditions like Hodgkin's lymphoma in youth, is a strong risk factor.
Interpreting the Results
The GAIL calculator typically provides two primary risk estimates:
5-Year Risk: The percentage chance of developing invasive breast cancer in the next five years.
Lifetime Risk: The percentage chance of developing invasive breast cancer at any point in the future.
A healthcare provider will interpret these scores in the context of your overall health, family history, and other clinical findings. Higher scores may suggest:
More frequent or earlier mammographic screening.
Discussion of risk-reducing medications (like tamoxifen or raloxifene).
Consideration of genetic testing if other factors suggest a hereditary predisposition.
Important Disclaimer
This calculator is intended for educational and informational purposes only. It is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read here.
function calculateGailRisk() {
var age = parseFloat(document.getElementById("age").value);
var num_first_degree_relatives = parseInt(document.getElementById("num_first_degree_relatives").value);
var history_breast_biopsy = parseInt(document.getElementById("history_breast_biopsy").value);
var history_atypical_hyperplasia = parseInt(document.getElementById("history_atypical_hyperplasia").value);
var number_of_breast_biopsies = parseInt(document.getElementById("number_of_breast_biopsies").value);
var personal_breast_cancer_history = parseInt(document.getElementById("personal_breast_cancer_history").value);
var radiation_therapy_age = parseFloat(document.getElementById("radiation_therapy_age").value);
var resultElement = document.getElementById("result");
// Basic validation
if (isNaN(age) || isNaN(num_first_degree_relatives) || isNaN(history_breast_biopsy) ||
isNaN(history_atypical_hyperplasia) || isNaN(number_of_breast_biopsies) ||
isNaN(personal_breast_cancer_history) || isNaN(radiation_therapy_age) ||
age < 0 || num_first_degree_relatives < 0 || number_of_breast_biopsies < 0 || radiation_therapy_age = 40) {
riskScore *= Math.pow(1.08, (age – 40));
}
// Relatives factor
if (num_first_degree_relatives === 1) {
riskScore *= 1.5;
} else if (num_first_degree_relatives >= 2) {
riskScore *= 2.5;
}
// History of Breast Biopsy factor
if (history_breast_biopsy === 1) {
riskScore *= 1.3;
}
// History of Atypical Hyperplasia factor
if (history_atypical_hyperplasia === 1) {
riskScore *= 2.0;
}
// Number of Breast Biopsies factor (simplified additional risk per biopsy)
if (number_of_breast_biopsies > 0) {
riskScore *= Math.pow(1.1, number_of_breast_biopsies);
}
// Personal History of Breast Cancer factor
if (personal_breast_cancer_history === 1) {
riskScore *= 2.2;
}
// Radiation Therapy factor (simplified: risk increase based on age at therapy)
if (radiation_therapy_age > 0 && radiation_therapy_age 30) {
riskScore *= 1.1; // Lower factor for therapy after 30
}
// Convert score to a percentage approximation for 5-year and Lifetime risk.
// IMPORTANT: This is a highly abstract representation. Real models are non-linear and more sophisticated.
var fiveYearRiskApprox = Math.min(riskScore * 0.5, 15); // Capped for simplicity
var lifetimeRiskApprox = Math.min(riskScore * 2.5, 60); // Capped for simplicity
// Format and display the result
resultElement.innerHTML = "Estimated 5-Year Risk: " + fiveYearRiskApprox.toFixed(2) + "%" +
"Estimated Lifetime Risk: " + lifetimeRiskApprox.toFixed(2) + "%";
}