Intra-operative measurement of tumour size in breast cancer and its comparison with other methods: a prospective study

V P Verma

doi:10.3332/ecancer.2008.96

Abstract

Accurate measurement of breast tumour size determines staging and prognosis. Discrepancies amongst clinical examination (CE), ultrasonography (USG), mammography, pathological examination (PE) and magnetic resonance imaging have been reported. However, few studies have evaluated changes in breast tumour size from the operating table to the laboratory.Objectives and methods:A prospective study was designed to assess the intra-operative (IO) tumour size in 29 patients of breast cancer presenting to a tertiary care centre in Delhi and to compare it with CE, USG and PE.Observations and results:Twenty-nine patients (mean age: 47 years), presenting with invasive duct carcinoma (stage IIIA: 31%, stage IIB: 28%), were included in the study. Comparison with mean IO (4.2 cm) revealed that both USG and PE underestimated tumour size by a mean of 0.35 cm (8.4%) and 0.45 cm (10.7%), respectively, in most patients. CE tended to overestimate size by 0.82 cm (19.8%). All three modalities showed statistically significant correlation with IO (maximum Pearson’s correlation coefficient for PE=0.937, p<0.001; R2=0.877, maximum for PE). Two-way analysis of variance revealed mean difference in size to be statistically significant (p=0.000) only between CE and IO.Discussion:Formalin processing causes changes in tumour dimensions in the breast, causing reduction in tumour size. It may also have a bearing on the assessment of surgical margins in breast conservation surgery. Immediate post-operative measurement of the specimen is ideal. Protocols for specimen fixation should be standardized.

Highlights

Tumour size is an independent prognostic factor in breast carcinoma and is a good predictor of lymph node metastases
Chest x-ray, and USG of the breast for tumour size were carried out on all patients. The latter was done by an experienced radiologist to minimize operator variation
Clinical examination was compared with pathological examination as early in 1983, and some 'adjustment' was attempted for skin and fat thickness, as it tends to result in overestimating the size [18]

Summary

Introduction

Tumour size is an independent prognostic factor in breast carcinoma and is a good predictor of lymph node metastases. The measurement of tumour size should be accurate as even small discrepancies can affect staging and treatment. Variation has been reported between imaging modalities (USG, MG), PE and CE [8,9,10]. There are no guidelines regarding the state of the specimen to be taken as the standard for staging, that is fresh or fixed. The threedimensional measurements are most and accurately obtained from the fresh gross specimen. Several reasons have been attributed to the disharmony in size between fresh and fixed specimens, including the use of formalin, the 'pancake phenomenon', compression during specimen radiography, tissue composition of the tumour, histological subtype [12,13,14]

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