Breast Cancer Prognosis (Nottingham Prognostic Index)

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Estimate breast cancer prognosis using the Nottingham Prognostic Index (NPI), a widely used score based on tumour size, lymph node involvement, and tumour grade. Enter the three factors to see the NPI value and its prognostic group.

Rates and fees change frequently. Always confirm the current figures with the official authority before relying on this result.

Formula

NPI = (0.2 × Tumour Size in cm) + Lymph Node Stage (1–3) + Tumour Grade (1–3)
  • The NPI combines the three strongest pathology predictors of breast cancer outcome into a single score.
  • Tumour size is weighted at 0.2 per centimetre; node stage and grade each add 1 to 3 points.
  • Lower scores indicate a better prognosis: ≤2.4 excellent, 2.4–3.4 good, 3.4–5.4 moderate, >5.4 poor.
  • The NPI estimates prognosis groups; it does not give an individual percentage risk of recurrence.
  • This is an educational tool — treatment decisions must be made with an oncology team using full clinical information.

2 cm tumour, no nodes, grade 2

Inputs
  • Tumour Size: 2 cm
  • Lymph Node Stage: 1
  • Tumour Grade: 2

NPI = (0.2 × 2) + 1 + 2 = 0.4 + 3 = 3.4, which falls in the 'good prognosis' group.

Frequently asked questions

What is the Nottingham Prognostic Index?
It's a well-established score that estimates breast cancer prognosis from tumour size, the number of involved lymph nodes, and the tumour's grade.
How are the prognostic groups defined?
Typically: NPI 2.0–2.4 excellent, 2.4–3.4 good, 3.4–5.4 moderate, and above 5.4 poor prognosis.
Does a lower NPI mean a better outcome?
Yes. Smaller tumours, fewer involved nodes, and lower grade all reduce the score and are associated with better survival.
Is the NPI a diagnosis?
No. It is a prognostic estimate to support clinical discussion, not a diagnosis or a substitute for specialist advice.