Table 1.
Studies evaluating syndecan-1, -2, -3, and -4 as biomarkers in ovarian cancer patients.
| N | Type of Sample | Detection | Relevant Finding | Reference |
|---|---|---|---|---|
| 50 control ovaries 20 primary OCs 17 omental metastases 7 normal omenta |
Frozen tissue | Gene expression | SDC1 upregulated in ovarian carcinoma tumor vs. normal ovary and in secondary omental metastases vs. normal omenta. | Casey RC et al., 2003 [16] |
| 115 EOC patients 10 benign epithelial ovarian tumor patients 12 controls |
FFPE tissue | IHC | SDC2, -3, and -4 were expressed in both normal ovary and benign and malignant ovarian tumors. Negative expression of SDC1 in controls, positive in tumors. Presence of stromal SDC1 and its intensity were associated with poor OS and PFS. |
Davies EJ et al., 2004 [17] |
| 138 EOC patients 17 atypical proliferative serous tumors 22 ovarian serous cystadenomas 12 controls |
FFPE tissue | RT-qPCR IHC |
SCD1 expression (mRNA and protein) upregulated in OC samples. | Salani R. et al., 2007 [18] |
| 111 patients | FFPE tissue | IHC | Epithelial SDC1: Lower expression in patients with advanced disease. Higher PFS in patients with negative expression. Stromal SDC1: Higher expression in patients with advanced disease. Lower PFS and OS in patients with high expression compared to patients with low expression. |
Kusumoto T et al., 2010 [19] |
| 26 EOC patients 5 borderline 27 benign 2 controls |
FFPE tissue | RT-qPCR IHC |
Negative expression of SDC1 in controls, positive in tumors, and in borderline samples. Expression of both syndecan-1 and its mRNA detected at the original site of the tumor and in the metastatic foci. |
Guo Q et al., 2015 [20] |
| 41 EOC patients | FFPE tissue | IHC | SDC1 expression higher in HGSC and clear cell carcinoma compared to LGSC. SDC1 expression correlated significantly to FIGO stage. | Hasby E.A. 2016 [21] |
| 154 EOC patients 38 benign 33 omental metastases |
FFPE tissue (TMAs) | IHC | High CD20 and SDC1 expression correlated significantly with high tumor grade. High SDC1 expression correlates with a poor OS and with poor ovarian cancer-specific survival. |
Lundgren et al., 2016 [22] |
| 26 late-stage ovarian cancer patients (pre- and post-cytoreductive surgery) | Serum | Multiplex array | SDC1 was significantly increased in the post-surgery samples compared to baseline conditions. | Klaschik S et al., 2019 [23] |
| Screening: 3 datasets from GEO database (GSE29156, GSE40595, and GSE14407) Validation: 10 EOC patients 10 benign |
Tissue Blood |
Screening: In silico analysis Validation: Gene expression analysis (custom designed mRNA set containing 48 genes) |
SDC3 was confirmed as potential biomarker. | Kulbe H et al., 2019 [24] |
| Datasets from TCGA and GEO repositories (GSE9891, GSE3149, GSE26193, and GSE63885) | Tissue | In silico analysis | Higher expression of SDC4 is correlated with poor OS. SDC4 expression increased across the tumor stage. |
Kim S et al., 2021 [25] |
| 3 datasets from GEO database (GSE38666, GSE40595, and GSE66957) | Tissue | In silico analysis (expression profiling, bioinformatic analysis) | Higher expression of SDC1 is correlated with poor OS. | Li X et al., 2022 [26] |
EOC: Epithelial ovarian cancer; FFPE: Formalin-Fixed Paraffin-Embedded; FIGO: International Federation of Gynaecology and Obstetrics; HGSC: High-grade serous carcinomas; IHC: Immunohistochemistry; LGSC: Low-grade serous carcinomas; mRNA: Messenger-RNA; PFS: Progression-free survival; OS: Overall survival; RT-qPCR: Reverse transcription polymerase chain reaction; SDC1: Syndecan-1; SDC2: Syndecan-2; SDC3: Syndecan-3; SDC4: Syndecan-4; TMA: Tissue microarrays.