New therapeutic strategy for gastric carcinoma: a two-step evaluation of malignant potential from its molecular biologic and pathologic characteristics.
OBJECTIVE
A previous study of ours indicated that platelet-derived growth factor-A (PDGF-A) mRNA expression in biopsy specimens can identify a subgroup of high-risk gastric carcinoma patients, while clinicopathologic studies have shown that lymph node involvement is an important risk factor for predicting overall survival. To identify gastric carcinoma patients at high risk for recurrence, we assessed a two-step evaluation consisting of mRNA expression of tumor growth-related factors and the histopathologic findings.


METHODS
The reverse transcriptase-polymerase chain reaction (RT-PCR) was used to assay the gene expression of PDGF-A and transforming growth factor-beta1 (TGF-beta1) in 69 gastric carcinoma endoscopic biopsy specimens (prospective cohort). The corresponding gastric carcinoma surgical specimens were classified histologically. Finally, the patients' survival curves were calculated. The relationships among the mRNA expression, histopathologic findings, and survival period were analyzed statistically.


RESULTS
Nodal involvement correlated with PDGF-A and TGF-beta1 mRNA expression in early and advanced carcinomas, respectively. Both PDGF-A mRNA and TGF-beta1 mRNA expression were independent preoperative prognostic indicators in advanced cases. The ratio of involved nodes (n1) to total perigastric lymph nodes dissected (percentage of involved nodes) was the most independent postoperative prognostic indicator in advanced cases. Early carcinomas were divided preoperatively into two types. Advanced carcinomas were divided preoperatively into three. These were divided again postoperatively according to the percentage of involved nodes into high- and low-malignacy groups.


CONCLUSIONS
A two-step evaluation of the malignant potential of gastric carcinoma by a combination of preoperative evaluation for PDGF-A and TGF-beta1 expression and postoperative pathologic examination would yield a more accurate prognosis for patients with gastric carcinoma.
Kuwahara
A
A
Department of Internal Medicine, Saga Medical School, Saga, Japan.
Katano
M
M
Nakamura
M
M
Fujimoto
K
K
Miyazaki
K
K
Mori
M
M
Morisaki
T
T
D006801:Humans; D008207:Lymphatic Metastasis; D010982:Platelet-Derived Growth Factor / Q000235:genetics; D012333:RNA, Messenger / Q000032:analysis; D013274:Stomach Neoplasms / Q000401:mortality / Q000473:pathology* / Q000601:surgery*; D016212:Transforming Growth Factor beta / Q000235:genetics
D010982:Platelet-Derived Growth Factor; D012333:RNA, Messenger; D016212:Transforming Growth Factor beta; C075278:platelet-derived growth factor A