Effect of experience of pathologist on the inter-observer reproducibility of the Nottingham grade

Introduction: Breast carcinoma is the most common solid malignant tumour. It is the commonest cancer among Sri Lankan females. Tumour grading is an important prognostic factor, determining the future management of the patient. Grading of the tumour should be consistent among the pathologists without significant inter-observer variation. This study examined whether the experience of pathologist has any effect on the inter-observer agreement of the histological grading system of invasive breast carcinoma.

Method: Two pathologists with different levels of experience in histopathology were involved in the study. They independently evaluated histological grade using the Nottingham modification of the Bloom and Richardson histological grading system on 47 cases of carcinoma of breast.

Results: Generalized kappa value for overall Nottingham grading was 0.61. Generalized kappa values were 0.5 and 0.51 for tubule formation and mitotic count respectively. The generalized kappa value for nuclear pleomorphism was 0.63.

Conclusion: The difference in the level of experience does not affect the final Nottingham grade of breast carcinoma.

Keywords: Nottingham grading; Inter-observer variation

DOI: 10.4038/gmj.v16i1.2902

Galle Medical Journal, Vol 16: No. 1, March 2011 pp.6-10