Prognostic significance of intraperitoneal cancer cells in gastric carcinoma: detection of cytokeratin 20 mRNA in peritoneal washes, in addition to detection of carcinoembryonic antigen.
BACKGROUND
In patients with gastric cancer, the presence of gastric cancer cells in the peritoneal cavity detected by cytologic examination, is a significant prognostic factor. A more sensitive, reverse transcriptase-polymerase chain reaction (RT-PCR) technique, amplifying carcinoembryonic antigen (CEA), was introduced as a new detection system, but produced some false-positive results. A search for other molecular markers is ongoing.


METHODS
Peritoneal washes were obtained from 195 patients with gastric carcinoma during surgery. Cytokeratin 20 (CK20) mRNA levels were quantified, in addition to those of CEA, using the LightCycler, and the feasibility of CK20 as a target was evaluated.


RESULTS
CK20 was limited, in terms of sensitivity, for detecting disseminated cancer cells (sensitivity, 63%; specificity, 91%; positive predictive value, 70%; and negative predictive value, 88%). Multimarker analysis was performed, in which samples positive for either CK20 or CEA mRNA were considered to be positive for cancer cells. Multivariate analysis identified the multimarker analysis as a significant independent prognostic determinant.


CONCLUSIONS
CK20 RT-PCR produced information that could add a significant impact to the knowledge obtained by CEA RT-PCR, although detection by CK20 alone was not sufficiently sensitive to replace CEA in the detection system.
Kodera
Yasuhiro
Y
Second Department of Surgery, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya 466-8550, Japan.
Nakanishi
Hayao
H
Ito
Seiji
S
Yamamura
Yoshitaka
Y
Fujiwara
Michitaka
M
Koike
Masahiko
M
Hibi
Kenji
K
Ito
Katsuki
K
Tatematsu
Masae
M
Nakao
Akimasa
A
D014408:Biomarkers, Tumor / Q000235:genetics / Q000378:metabolism; D002272:Carcinoembryonic Antigen / Q000235:genetics* / Q000378:metabolism; D006801:Humans; D007381:Intermediate Filament Proteins / Q000235:genetics* / Q000378:metabolism; D053554:Keratin-20; D008207:Lymphatic Metastasis / Q000175:diagnosis; D009361:Neoplasm Invasiveness / Q000175:diagnosis; D009367:Neoplasm Staging; D010533:Peritoneal Lavage; D010534:Peritoneal Neoplasms / Q000235:genetics* / Q000378:metabolism / Q000556:secondary; D011379:Prognosis; D012333:RNA, Messenger / Q000032:analysis*; D012334:RNA, Neoplasm / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012680:Sensitivity and Specificity; D013274:Stomach Neoplasms / Q000235:genetics* / Q000378:metabolism; D015996:Survival Rate
D014408:Biomarkers, Tumor; D002272:Carcinoembryonic Antigen; D007381:Intermediate Filament Proteins; C507499:KRT20 protein, human; D053554:Keratin-20; D012333:RNA, Messenger; D012334:RNA, Neoplasm