What is the Gail Model?

The Gail Model is a statistical tool developed by Dr. Mitchell Gail at the National Cancer Institute. It estimates a woman's probability of developing invasive breast cancer over 5 years and over a lifetime, using risk factors such as age, family history, biopsy history, and age at first live birth.

How accurate is this calculator?

This tool uses the simplified Gail Model coefficients and provides an estimate, not a clinical diagnosis. The full NCI model requires additional data and professional interpretation. Always consult a physician or genetic counselor for clinical decision-making.

What counts as a first-degree relative?

First-degree relatives include your mother, sisters, and daughters. Half-siblings on the maternal side also count. Paternal relatives are not included in the standard Gail Model.

What is atypical hyperplasia?

Atypical hyperplasia (atypia) is a benign but abnormal cell growth found during a breast biopsy. Its presence roughly doubles the risk contribution of a prior biopsy in the Gail Model.

What is considered high risk?

A 5-year risk above 1.67% is generally used as the threshold for clinical interventions such as chemoprevention discussions. A lifetime risk above 20–25% may qualify for enhanced MRI surveillance, per major guidelines.

Breast Cancer Risk (Gail Model)

Name: Breast Cancer Risk (Gail Model)
Availability: InStock
Author: Nham Vu

Enter age, family history, biopsy history, and first-birth age to get your estimated 5-year and lifetime breast cancer risk per the Gail Model.

Risk Factors

Current age (35–85)

First-degree relatives with breast cancer

Mother, sisters, and daughters only.

Number of prior breast biopsies

Atypical hyperplasia on any biopsy?

Age at first live birth

This tool is for educational purposes only and does not constitute medical advice.

Fill in the risk factors and click Calculate Risk to see results.

Summary

Enter age, family history, biopsy history, and first-birth age to get your estimated 5-year and lifetime breast cancer risk per the Gail Model.

How it works

Enter your current age (35–85).
Select the number of first-degree relatives (mother, sisters, daughters) diagnosed with breast cancer.
Indicate the number of prior breast biopsies and whether any showed atypical hyperplasia.
Select your age at first live birth (or if you have never been pregnant).
Click Calculate to see your estimated 5-year and lifetime risk percentages.

Use cases

Understanding personal breast cancer risk before a routine mammogram.
Discussing screening frequency with a primary care physician.
Evaluating eligibility for chemoprevention or enhanced surveillance programs.
Educational use to understand which risk factors influence the Gail Model score.

Frequently Asked Questions

Last updated: 2026-07-22 · Reviewed by Nham Vu