Table 6.
Results of Imprint Cytology and the One Step Nucleic Acid Amplification Breast Cancer System Compared With Reference Pathologya
| Reference Pathology | |||||
|---|---|---|---|---|---|
| Macro | Micro | ITC | Negative | Total | |
| Imprint cytology, n =532b | |||||
| Positive | 41 | 10 | 0 | 3 | 54 |
| Negative | 14 | 15 | 8 | 436 | 473 |
| Indeterminate | 1 | 0 | 0 | 4 | 5 |
| Total | 56 | 25 | 8 | 443 | 532 |
| OSNA, n =532c | |||||
| ++ | 48 | 6 | 1 | 4 | 59 |
| + | 4 | 7 | 0 | 14 | 25 |
| − | 4 | 12 | 7 | 425 | 448 |
| Total | 56 | 25 | 8 | 443 | 532 |
Macro indicates macrometastasis; Micro, micrometastasis; ITC, isolated tumor cells; OSNA, the One Step Nucleic Acid Amplification Breast Cancer System.
In total, 532 sentinel lymph nodes that were obtained from 272 patients enrolled from 7 clinical sites were evaluated intraoperatively by imprint cytology before either OSNA or postoperative reference pathology. Criteria for macrometastasis, micrometastasis, ITCs, or negative findings followed American Joint Committee on Cancer Staging Manual (6th edition) guidelines.
Imprint cytology results were classified as positive, negative, or indeterminate.
OSNA results were classified as ++ (macrometastasis), + (micrometastasis), or − (negative), as determined by a pre-established cutoff number of cytokeratin 19 messenger RNA copies.