Which AJCC edition does this tool use?

This tool implements the AJCC Cancer Staging Manual, 8th Edition (2017) anatomic stage groups for breast cancer.

Does M1 always mean Stage IV?

Yes. Any combination of T and N with M1 (distant metastasis) is classified as Stage IV regardless of tumor size or nodal involvement.

What is the difference between clinical and pathologic staging?

Clinical staging uses imaging and physical exam before surgery; pathologic staging uses surgical specimens. The T, N, M values you enter should match whichever staging type applies to your case.

Is Tis always Stage 0?

Yes. Tis (carcinoma in situ) with N0 and M0 is Stage 0 by definition.

What does TX or NX mean?

TX means the primary tumor cannot be assessed; NX means regional lymph nodes cannot be assessed. These indeterminate categories are shown but do not produce a definitive stage group.

Is this tool a substitute for clinical judgment?

No. This tool is for educational and reference purposes only. Staging decisions for patient care must be made by qualified clinicians using complete pathologic and clinical data.

TNM Staging Breast Cancer

Select T, N, and M values to instantly look up the AJCC 8th edition stage group for breast cancer.

TNM Input

Select one value per category, then read your stage on the right.

T — Primary Tumor

N — Regional Lymph Nodes

M — Distant Metastasis

Select T, N, and M values, then click Determine Stage.

Summary

This tool applies the AJCC 8th Edition TNM staging system for breast cancer. Choose your tumor size (T), lymph node involvement (N), and distant metastasis (M) values to see the corresponding anatomic stage group. All calculations run locally in your browser — no data is sent to any server.

How it works

Select the T (tumor size/extent) category that best matches the clinical or pathologic findings.
Select the N (regional lymph node) category reflecting lymph node involvement.
Select M0 (no distant metastasis) or M1 (distant metastasis present).
The tool immediately displays the AJCC 8th Edition anatomic stage group.
A color-coded badge and plain-language explanation help interpret the result.

Use cases

Quickly cross-check a staging assignment during chart review.
Educate students and residents on the TNM classification system.
Verify staging before preparing a tumor board presentation.
Explore how different T/N combinations affect the overall stage.
Reference staging logic without opening a physical staging manual.

Frequently Asked Questions

Last updated: 2026-09-30 · Reviewed by Nham Vu