Low sensitivity of the touch imprint cytology of the sentinel lymph node in breast cancer patients--results of a large series.

Background And Objectives: Touch imprint cytology (TIC) was reported to be a sensitive method of intraoperative sentinel lymph node (SLN) assessment. The objective of our study was to assess the value of the TIC as an intraoperative SLN evaluation method and to determine a subgroup of patients in whom TIC should not be indicated.

Methods: In 250 breast cancer patients with SLN biopsy, TIC of SLNs was performed intraoperatively. The results of TIC were compared to the final histopathological analysis of SLNs. A subgroup analysis of the TIC value was performed with regard to the tumor size.

Results: SLN metastases were found in 102/250 patients (41%). Two cases were false positive. The sensitivity of TIC was 34%, specificity 98.6%, accuracy 72%, negative predictive value 69%, and positive predictive value 95%. TIC was significantly more sensitive to detect macrometastases (32/43) compared to micrometastases or ITC (3/59) (P < 0.001). TIC was positive in only 5% (4/77) in T < 10 mm tumors compared to 18% (31/168) in T > 10 mm (P = 0.01).

Conclusions: TIC is a simple, quick, and sensitive method of intraoperative SLNs evaluation for the presence of the macrometastases. TIC has a very limited value in detecting micrometastases and no value in detecting ITC. TIC may not be indicated in T1a + b tumors.