Haybittle JL, Blamey RW, Elston CW, Johnson J, Doyle PJ, Campbell FC, et al.
"A prognostic index in primary breast cancer."
Br J Cancer. 1982 Mar; 45(3):361-6.
I➜The Nottingham prognostic index (abbreviated NPI) is a widely used clinicopathological staging system for primary breast cancer prognostication. It was developed in 1982
Its value is calculated using three pathological criteria:
- the size (S) in centimeters of the lesion
- the number (N) of involved lymph nodes (score: 1-3)
- the tumour grade (G), based on the modified Bloom-Richardson grading system (score: 1-3).
Formula: NPI = (S x 0.2) + N + G