Important Disclaimer: This calculator is based on simplified statistical models (inspired by the Gail Model). It is for educational purposes only and does not provide a medical diagnosis. A "low risk" score does not guarantee you will not get cancer, and a "high risk" score does not mean you will. Always consult a healthcare professional for clinical screenings and personalized advice.
Understanding Breast Cancer Risk Assessment
The Breast Cancer Risk Assessment Tool is designed to help women and healthcare providers estimate the likelihood of developing invasive breast cancer over a specific period. Our calculator uses key factors such as age, reproductive history, and family history to provide an estimate based on clinical patterns.
Key Factors Influencing Your Score
Age: The risk of breast cancer increases as you get older. Most breast cancers are diagnosed in women over age 50.
Menstrual History: Starting periods early (before age 12) exposes the body to estrogen for a longer duration, slightly increasing risk.
Reproductive History: Having a first child after age 30 or never having a full-term pregnancy can increase the statistical risk.
Family History: Having a first-degree relative (mother, sister, or daughter) with breast cancer significantly increases personal risk due to shared genetics and environments.
Biopsy History: Previous breast biopsies, especially those showing atypical hyperplasia, are strong indicators of increased risk.
Realistic Example:
A 50-year-old woman who started her period at age 13, had her first child at 22, has no family history of breast cancer, and has never had a biopsy, typically has a 5-year risk of approximately 1.1% to 1.3%. This is considered an average risk for her age group.
What Does the Percentage Mean?
A 5-year risk score of 1.67% or higher is often classified as "high risk" by clinical standards (such as those used for chemoprevention eligibility). However, risk is a spectrum. Many women with scores above 1.67% never develop breast cancer, while some with lower scores do. The primary goal of this tool is to prompt a meaningful conversation with your doctor about screening schedules, such as mammograms or MRIs.
How to Reduce Your Risk
While some factors like age and genetics cannot be changed, lifestyle modifications can help lower your overall risk:
Maintain a healthy weight, especially after menopause.
Stay physically active with regular exercise.
Limit alcohol consumption.
Discuss the risks and benefits of hormone replacement therapy (HRT) with your doctor.
Breastfeed if possible, as it has been shown to have a protective effect.
function calculateBCRisk() {
var age = parseFloat(document.getElementById('currentAge').value);
var menarche = parseFloat(document.getElementById('menarcheAge').value);
var birth = parseFloat(document.getElementById('firstBirthAge').value);
var relatives = parseFloat(document.getElementById('relativesCount').value);
var biopsy = parseFloat(document.getElementById('biopsyCount').value);
var resultArea = document.getElementById('bcResultArea');
var scoreDisplay = document.getElementById('bcRiskScore');
var interpretation = document.getElementById('bcInterpretation');
if (isNaN(age) || age = 35 && age = 40 && age = 45 && age = 50 && age = 55 && age = 60 && age = 65 && age = 70) baseRisk = 2.7;
// Apply multipliers based on the logic of the Gail Model
// These multipliers simulate the weight of each risk factor
var calculatedRisk = baseRisk * menarche * birth * relatives * biopsy;
// Cap the risk logically for a 5-year window in a general tool
if (calculatedRisk > 15) calculatedRisk = 15.0;
// Formatting result
var finalScore = calculatedRisk.toFixed(2);
scoreDisplay.innerHTML = finalScore + "%";
// Interpretation logic
if (calculatedRisk = 1.2 && calculatedRisk < 1.67) {
interpretation.innerHTML = "Result: Average 5-year risk.";
interpretation.style.color = "#f57c00";
} else {
interpretation.innerHTML = "Result: Elevated 5-year risk. Consult your physician.";
interpretation.style.color = "#c62828";
}
resultArea.style.display = 'block';
// Scroll to result
resultArea.scrollIntoView({ behavior: 'smooth', block: 'nearest' });
}