Nottingham prognostic index

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The Nottingham Prognostic Index was developed in 1982 as an aid to the management of breast cancer.[1][2][3]

By using multivariate analysis, 3 factors were found to be significant: tumour grade, number of lymph nodes involved and size of the tumour.

Tumour grade (G) gives a score 1-3 based on the modified Bloom-Richardson grading

Lymph node involvement (L) gives a score 1-3

  1. No nodes
  2. 1-3 nodes
  3. >3 nodes

With sentinel lymph node sampling replacing axillary sampling/clearance, a negative sentinel lymph node is regarded as node negative.

With tumour size in cm (S) factored in, the NPI can be worked out by:

 G + L + (S \times 0.2)

This has been shown to give the following prognoses:

NPI and survival
NPI score Prognosis 5-year survival
2.0-2.4 Excellent 93%
2.4-3.4 Good 85%
3.4-5.4 Moderate 70%
>5.4 Poor 50%

As a semi-quantitative score, other divisions are possible, e.g. into 5 categories.

The NICE DG10 guidelines use the 4-category division indicated in the table, recommending Oncotype DX testing in moderate risk tumours to help guide decisions on adjuvant chemotherapy.[4]