Clinical assessment of tumour size in primary breast carcinoma.

In a consecutive series of 100 operable breast carcinomas clinical and mammographic assessment of tumour size each resulted in only 75% being placed in the correct T category when compared to the actual tumour size. In a further 50 breast carcinomas it was shown that an accurate assessment of actual tumour size could be obtained by subtracting the thickness of the skin, fat and subcutaneous tissue in the corresponding area in the contralateral breast from the clinical measurement obtained using calipers (adjusted clinical size). The T category using this method was correct in 49 out of the 50, significantly better than clinical measurement or mammographic assessment of tumour size (p less than 0.003 McNemar's Test). Analysis of the regression lines obtained comparing clinical measurement, mammographic assessment and adjusted clinical size with actual tumour size showed that: clinical measurement overestimated actual tumour size by 0.5 to 1 cm; mammographic assessment overestimated small tumour and underestimated larger ones, whereas the adjusted clinical size never differed by more than a fraction of a centimeter from the actual size. This new method of assessment of tumour size allows accurate pre-operative selection of patients into appropriate treatment options.