One-step nucleic acid amplification for intraoperative detection of lymph node metastasis in breast cancer patients.
OBJECTIVE
Detection of sentinel lymph node (SLN) metastasis in breast cancer patients has conventionally been determined by intraoperative histopathologic examination of frozen sections followed by definitive postoperative examination of permanent sections. The purpose of this study is to develop a more efficient method for intraoperative detection of lymph node metastasis.


METHODS
Cutoff values to distinguish macrometastasis, micrometastasis, and nonmetastasis were determined by measuring cytokeratin 19 (CK19) mRNA in histopathologically positive and negative lymph nodes using one-step nucleic acid amplification (OSNA). In an intraoperative clinical study involving six facilities, 325 lymph nodes (101 patients), including 81 SLNs, were divided into four blocks. Alternate blocks were used for the OSNA assay with CK19 mRNA, and the remaining blocks were used for H&E and CK19 immunohistochemistry-based three-level histopathologic examination. The results from the two methods were then compared.


RESULTS
We established CK19 mRNA cutoff values of 2.5 x 10(2) and 5 x 10(3) copies/muL. In the clinical study, an overall concordance rate between the OSNA assay and the three-level histopathology was 98.2%. Similar results were obtained with 81 SLNs. The OSNA assay discriminated macrometastasis from micrometastasis. No false positive was observed in the OSNA assay of 144 histopathologically negative lymph nodes from pN0 patients, indicating an extremely low false positive for the OSNA assay.


CONCLUSIONS
The OSNA assay of half of a lymph node provided results similar to those of three-level histopathology. Clinical results indicate that the OSNA assay provides a useful intraoperative detection method of lymph node metastasis in breast cancer patients.
Tsujimoto
Masahiko
M
Department of Pathology, Osaka Police Hospital, Japan.
Nakabayashi
Kadzuki
K
Yoshidome
Katsuhide
K
Kaneko
Tomoyo
T
Iwase
Takuji
T
Akiyama
Futoshi
F
Kato
Yo
Y
Tsuda
Hitoshi
H
Ueda
Shigeto
S
Sato
Kazuhiko
K
Tamaki
Yasuhiro
Y
Noguchi
Shinzaburo
S
Kataoka
Tatsuki R
TR
Nakajima
Hiromu
H
Komoike
Yoshifumi
Y
Inaji
Hideo
H
Tsugawa
Koichiro
K
Suzuki
Koyu
K
Nakamura
Seigo
S
Daitoh
Motonari
M
Otomo
Yasuhiro
Y
Matsuura
Nariaki
N
D001483:Base Sequence; D001943:Breast Neoplasms / Q000737:chemistry / Q000473:pathology* / Q000601:surgery; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D007432:Intraoperative Period; D053539:Keratin-19 / Q000032:analysis; D008207:Lymphatic Metastasis; D008969:Molecular Sequence Data; D021141:Nucleic Acid Amplification Techniques / Q000379:methods*
D053539:Keratin-19