The utility of rapid diagnosis of lymph node metastasis in gastric cancer using a multiplex real-time reverse transcription polymerase chain reaction assay.
BACKGROUND
Lymph node metastasis is the most important prognostic factor in gastric cancer. However, diagnosis by hematoxylin and eosin staining or immunohistochemistry is not always sufficient for the detection of cancer cells because only representative number of slices are examined. Cancer cells may, therefore, be missed by traditional histological methods. Recently, reverse transcription polymerase chain reaction (RT-PCR) methods have been introduced for improved detection of cancer cells. The purpose of this study was to evaluate the utility of a prototype RT-PCR assay run on the Cepheid SmartCycler system compared to conventional RT-PCR using the LightCycler system.


METHODS
Forty-seven overt metastatic lymph nodes from 8 patients with advanced gastric cancer and 22 benign lymph nodes from patients without malignant tumor who received surgery were obtained with informed consent. We examined the lymph nodes by RT-PCR, using markers for CEA and CK19 and the LightCycler and SmartCycler systems.


RESULTS
In the singlex assay, the sensitivity of CEA and CK19 was 91.5 and 70.2% in the LightCycler system, and 97.9 and 95.7% in the SmartCycler system, respectively. In the multiplex assay, the sensitivity was 91.5% in the LightCycler system and 100% in the SmartCycler system, respectively.


CONCLUSIONS
In this study, rapid diagnosis using RT-PCR by the SmartCycler system had higher accuracy for detecting lymph node metastasis than the conventional LightCycler system. The SmartCycler system is more effective for the diagnosis of lymph node metastasis in gastric cancer when run with the prototype assay.
Yanagita
Shigehiro
S
Department of Surgical Oncology and Digestive Surgery, Field of Oncology, Course of Advanced Therapeutics, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima, Japan. y0810@m.kufm.kagoshima-u.ac.jp
Natsugoe
Shoji
S
Uenosono
Yoshikazu
Y
Arigami
Takaaki
T
Funasako
Yawara
Y
Hirata
Munetugu
M
Kozono
Tsutomu
T
Ehi
Katsuhiko
K
Arima
Hideo
H
Green
George
G
Wang
Yixin
Y
Aikou
Takashi
T
D002272:Carcinoembryonic Antigen / Q000235:genetics; D006801:Humans; D053539:Keratin-19 / Q000235:genetics; D008207:Lymphatic Metastasis; D012333:RNA, Messenger / Q000032:analysis; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods*; D012680:Sensitivity and Specificity; D013274:Stomach Neoplasms / Q000473:pathology*
D002272:Carcinoembryonic Antigen; D053539:Keratin-19; D012333:RNA, Messenger