Quantitative detection of disseminated free cancer cells in peritoneal washes with real-time reverse transcriptase-polymerase chain reaction: a sensitive predictor of outcome for patients with gastric carcinoma.
OBJECTIVE
To evaluate the feasibility of real-time reverse transcriptase-polymerase chain reaction (RT-PCR) detection of free cancer cells in the peritoneal washes as a prognostic indicator for patients with gastric carcinoma.


BACKGROUND
Peritoneal lavage cytology (CY) is an excellent prognostic determinant but lacks sensitivity. This can be improved by using RT-PCR to quantitate carcinoembryonic antigen (CEA) mRNA in peritoneal washes.


METHODS
Peritoneal washes were obtained from 189 patients with gastric carcinoma during laparotomy. CEA mRNA levels and CEA/GAPDH mRNA ratios were quantified using a real-time PCR system with fluorescent hybridization probes. Receiver-operating characteristic plots were used to determine which of these parameters should be used as a marker for the intraperitoneal cancer cells. The prognostic significance of its positivity was then evaluated by Kaplan-Meier curves, and its value as an independent prognostic factor was evaluated by multivariate analysis.


RESULTS
The sensitivity and specificity of real-time RT-PCR with an optimal cutoff value were 80% and 94%; those for conventional cytology were 56% and 91%. The survival of 16 patients who were CY-PCR+ was poor and approached that of 35 CY+ patients. Recurrence as peritoneal carcinomatosis was frequent among PCR+ patients but rare for their PCR- counterparts. PCR+ was a significant independent prognostic factor, along with the presence of node metastasis and serosal invasion, but CY+ was not.


CONCLUSIONS
Quantitative RT-PCR of peritoneal washes can replace cytologic examination as a tool for the sensitive evaluation of the risk of intraperitoneal recurrence in patients with gastric carcinoma.
Kodera
Yasuhiro
Y
Department of Gastroenterological Surgery, Aichi Cancer Center Hospital, Nagoya/Aichi, Japan. ykodera@mvi.biglobe.ne.jp
Nakanishi
Hayao
H
Ito
Seiji
S
Yamamura
Yoshitaka
Y
Kanemitsu
Yukihide
Y
Shimizu
Yasuhiro
Y
Hirai
Takashi
T
Yasui
Kenzo
K
Kato
Tomoyuki
T
Tatematsu
Masae
M
D000230:Adenocarcinoma / Q000235:genetics* / Q000401:mortality / Q000473:pathology; D001202:Ascitic Fluid / Q000235:genetics* / Q000473:pathology; D002272:Carcinoembryonic Antigen / Q000235:genetics; D003199:Computer Systems; D005069:Evaluation Studies as Topic; D005240:Feasibility Studies; D006801:Humans; D017063:Outcome Assessment, Health Care; D011237:Predictive Value of Tests; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012680:Sensitivity and Specificity; D013274:Stomach Neoplasms / Q000235:genetics* / Q000401:mortality / Q000473:pathology; D016019:Survival Analysis
D002272:Carcinoembryonic Antigen