Detection of minimal gastric cancer cells in peritoneal washings by focused microarray analysis with multiple markers: clinical implications.
BACKGROUND
Peritoneal cytology is an important prognostic factor of gastric cancer. However, peritoneal cytology requires great skill, which may explain its low prevalence. A reverse transcriptase-polymerase chain reaction-based assay with multiple marker genes or immunocytochemistry was assessed as an alternative method of gathering the same kind of data as cytology.


METHODS
Peritoneal washings from 179 patients with gastric cancer were analyzed by multiplex reverse transcriptase-polymerase chain reaction with 10 marker genes and subsequent hybridization to a customized oligo-nucleotide array. Results with this assay were either validated as a prognostic factor or confirmed by demonstrating the presence of cancer cells by immunocytochemical cytology.


RESULTS
Only 1 (2.2%) of 44 disease-free cases was shown to be positive by the microarray assay, whereas 13 (93%) of 14 conventional cytology-positive cases were found to be positive. This assay further detected approximately one-third of cytology-negative patients either with peritoneal recurrence (7 of 20, 35%) or with non-peritoneal recurrence (6 of 22, 27%). A high concordance between the microarray assay and immunocytochemical cytology with five antibodies against CK20, FABP1, MUC2, TFF1, and MASPIN was confirmed. The clinical outcome of the microarray assay-positive cases was poor, as was that of the cytology-positive cases.


CONCLUSIONS
Our assay, though time-consuming and requiring special equipment, demonstrated a specificity and sensitivity equal to or better than cytology in our institutes. The minimal free peritoneal cancer cells detected by the microarray assay may provide the same clinical information as larger amounts of cancer cells for patients with gastric cancer. An anti-MASPIN antibody may be helpful in peritoneal cytology of gastric cancer.
Mori
Kazuhiko
K
Department of Gastrointestinal Surgery, University of Tokyo Graduate School of Medicine, Hongo 7-3-1, Bunkyo-ku, Tokyo, 113-8655, Japan.
Suzuki
Tomohiro
T
Uozaki
Hiroshi
H
Nakanishi
Hayao
H
Ueda
Tetsuya
T
Matsuno
Yoshihiro
Y
Kodera
Yasuhiro
Y
Sakamoto
Hiromi
H
Yamamoto
Nobuko
N
Sasako
Mitsuru
M
Kaminishi
Michio
M
Sasaki
Hiroki
H
D014408:Biomarkers, Tumor / Q000235:genetics*; D003581:Cytodiagnosis; D050556:Fatty Acid-Binding Proteins / Q000235:genetics / Q000378:metabolism; D020869:Gene Expression Profiling; D005819:Genetic Markers; D006801:Humans; D053554:Keratin-20 / Q000235:genetics / Q000378:metabolism; D055262:Mucin-2; D009077:Mucins / Q000235:genetics / Q000378:metabolism; D009364:Neoplasm Recurrence, Local / Q000175:diagnosis; D020411:Oligonucleotide Array Sequence Analysis; D010533:Peritoneal Lavage; D010534:Peritoneal Neoplasms / Q000175:diagnosis* / Q000556:secondary; D011379:Prognosis; D012333:RNA, Messenger / Q000235:genetics; D012334:RNA, Neoplasm / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015843:Serpins / Q000235:genetics / Q000378:metabolism; D013274:Stomach Neoplasms / Q000175:diagnosis* / Q000235:genetics* / Q000473:pathology; D000071163:Trefoil Factor-1; D025521:Tumor Suppressor Proteins / Q000235:genetics / Q000378:metabolism
D014408:Biomarkers, Tumor; C493319:FABP1 protein, human; D050556:Fatty Acid-Binding Proteins; D005819:Genetic Markers; C507499:KRT20 protein, human; D053554:Keratin-20; C524625:MUC2 protein, human; D055262:Mucin-2; D009077:Mucins; D012333:RNA, Messenger; D012334:RNA, Neoplasm; C085344:SERPIN-B5; D015843:Serpins; C051838:TFF1 protein, human; D000071163:Trefoil Factor-1; D025521:Tumor Suppressor Proteins