Molecular detection of disseminated cancer cells in the peripheral blood and expression of sialylated antigens in colon cancers.
OBJECTIVE
To improve the survival rate of patients with colon cancer, liver metastases must be eradicated in a clinically occult state. This study was designed to find a predictor for potential liver metastases or micrometastases in colon cancer.


METHODS
Peripheral blood samples and tumor specimens were obtained from 36 patients with colon cancers. The blood samples were subjected to reverse transcriptase-polymerase chain reaction (RT-PCR) analysis, and the expression of sialylated carbohydrates was also investigated in the tumors immunohistochemically.


RESULTS
A carcinoembryonic antigen (CEA)-specific signal in the blood was detected in 9 of 12 (75%) patients with liver metastasis and in 8 of 24 (33%) patients without liver metastasis, respectively (P < 0.05). The positive rates of sialyl Lewis A (sLeA) and sialyl Lewis X (sLeX) were 36.3% and 40% in tumors without liver metastasis vs. 58.3% and 100% with liver metastasis, respectively. Within a year after surgery, liver metastases became clinically evident in three of the four patients without liver metastasis who showed a CEA-positive signal in their blood preoperatively and who had tumors with a strong expression of sLeX.


CONCLUSIONS
A combination of both markers may provide prognostic information for liver metastases in colon cancer.
Ichikawa
D
D
Department of Surgery, Kyoto First Red Cross Hospital, Kyoto, Japan.
Kitamura
K
K
Tani
N
N
Nishida
S
S
Tsurutome
H
H
Hakomori
S
S
Ikeda
E
E
Mutoh
F
F
Kurioka
H
H
Yamagishi
H
H
D003110:Colonic Neoplasms / Q000235:genetics* / Q000473:pathology*; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D007150:Immunohistochemistry; D016256:Lewis X Antigen / Q000032:analysis*; D008113:Liver Neoplasms / Q000175:diagnosis* / Q000556:secondary*; D009844:Oligosaccharides / Q000032:analysis*; D011237:Predictive Value of Tests; D012334:RNA, Neoplasm / Q000032:analysis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D000080506:Sialyl Lewis X Antigen
D016256:Lewis X Antigen; D009844:Oligosaccharides; D012334:RNA, Neoplasm; D000080506:Sialyl Lewis X Antigen