Editorial
The Clinical Value of Cancer Stem Cell Markers in Gastric Cancer
Weihua Fu*
Department of General Surgery, Tianjin Medical University General Hospital, China
*Corresponding author: Weihua Fu, Department of General Surgery, Tianjin Medical University General Hospital, 154 Anshan Road, Heping District, Tianjin 300052, China
Published: 06 Jan, 2017
Cite this article as: Fu W. The Clinical Value of Cancer
Stem Cell Markers in Gastric Cancer.
Clin Oncol. 2017; 2: 1188.
Editorial
Nowadays, gastric cancer remains the life-threatening complaint in spite of advanced surgical
procedures and other methods, such as radiotherapy and chemotherapy, having improved
the overall survival of patients dramatically. According to the statistics, gastric cancer ranks the
fifth most common cancer, meanwhile the third leading cause of cancer patients. To further
improve the prognosis of patients with gastric cancer, investigations of mechanisms towards
gastric carcinogenesis and invasion appear in full swing. Hereinto, several genetic biomarkers have
been regarded as prognostic factors of gastric cancer and might be helpful to individual treatment.
Accumulating evidence has suggested that cancer is hierarchically organized, with only a rare
subpopulation of cancer cells termed cancer stem cells (CSCs). CSC has been identified to play
vital roles in the initial, dissemination and recurrence of numerous solid tumors, including gastric
cancer. The identification of CSC is still controversial, the most common method is labeling the
special markers expressing on the tumor cell surface by Immunohistochemistry.
Recently, CD44 and CD133 present the novel and the most robust CSC markers in many solid
tumors, such as colon cancer, breast cancer. However, the evidence to determine the clinical value of
CD44 and CD133 remains insufficient, partially because much existing evidence is conflicting. We
performed a meta-analysis to elucidate whether CD44 or CD133 overexpression would correlate
with gastric cancer clinicopathology and prognosis, and to explain which of these markers would
have more clinical value based on the meta-analysis evidence. 26 Studies included in this metaanalysis
with a total of 4729 involved patients. The eligible studies were published between 1993
and 2015. The results demonstrated that high expression of CD44 was associated with Lauren type
(intestinal type) and lymphatic vessel invasion. CD133 over-expression was related to high TNM
stage (III/IV), high depth of invasion (T3/T4), lymph node metastasis, vascular invasion, and distant
metastasis. In addition, survival analysis demonstrated a significant association between CD44, as
well as CD133 and poor 5-year overall survival. Based on our results, combined detection of CD44
and CD133 expression can be an especially effective tool for pathological diagnosis and prognostic
prediction of gastric cancer patients in clinical applications.
As one of the variant of CD44, CD44v6 has been extensively studied in many tumors and its
prognostic value has been reported. Moreover, the monoclonal antibodies of CD44v6 have been
identified their target-therapy potential. Despite, several clinical studies were carried out to evaluate
the relationship of CD44v6 expression with clinicopathology and prognosis of gastric cancer,
no consistent finding was available. Hence, a meta-analysis of published data was performed
to systematically elucidate whether CD44v6 overexpression would have correlations with the
diagnostic and prognostic value in patients with gastric cancer. 16 eligible articles with 2177 gastric
cancer patients were included in this meta-analysis, the publication years of all studies ranged from
1995 to 2015. Among this study, Five studies including 913 patients were assessed for the correlation
between CD44v6 and 5-year overall survival (OS). The results showed that the upregulated CD44v6
was associated with lymph node metastasis, distant metastasis, high TNM stage, lymphatic vessel
invasion and vascular invasion. Pooled HR indicated that CD44v6 positive expression was correlated
poor 5-year OS. Taken together, CD44v6 overexpression was correlated to the characteristics of
tumor metastasis in gastric cancer, consisting with many mechanism studies. Thus, clinicians
should closely follow up the gastric cancer patients with CD44v6 upregulation in consideration of
their high risk for metastasis.
There also many other CSC markers in gastric cancer, such as SOX-2, Lgr-5, ALDH1. The Clinical
value of these markers may need more research to support, meanwhile, the detail mechanism of
CSC in tumor invasion and metastasis of gastric cancer also need further research.