CA9 level in renal cyst fluid: a possible molecular diagnosis of malignant tumours

Abstract

The fluid of malignant cystic renal tumours contains a high level of CA9 protein. The measurement of CA9 level in cyst fluid may be used as a molecular diagnosis for differentiation between malignant and benign renal cystic masses.

Advances in Proximal Fluid Proteomics for Disease Biomarker Discovery

“…Cyst fluid of the mammary apocrine cyst has been characterized using proteomic and IHC approaches . In an immunoassay of renal cyst fluid obtained from 28 patients by fine-needle aspiration, elevated carbonic anhydrase 9 levels were found in all 16 malignant tumors and not in 11 out of 12 benign cystic tumors . Glutathione S-transferase P1−1 levels have been shown to be higher in ovarian cyst fluid from malignant tumors as compared with benign tumors by ELISA, from a population of 165 patients .…”

“…50 In an immunoassay of renal cyst fluid obtained from 28 patients by fine-needle aspiration, elevated carbonic anhydrase 9 levels were found in all 16 malignant tumors and not in 11 out of 12 benign cystic tumors. 51 Glutathione S-transferase P1-1 levels have been shown to be higher in ovarian cyst fluid from malignant tumors as compared with benign tumors by ELISA, from a population of 165 patients. 52 O-linked glycans have been isolated from ovarian cyst glycoproteins and characterized by MS analysis to identify blood group active glycotopes.…”

Renal mass sampling: An enlightened perspective

“…used PCR to amplify CA‐IX in FNA specimens and reported enhanced sensitivity (53 to 68%), specificity (71 to 100%) and positive predictive value (88 to 100%) for clear cell RCC, as compared with FNA alone 114 . Similarly, CA‐IX testing of aspirated fluid from renal cysts has been shown to be useful in distinguishing between malignant and benign lesions 101 …”

“…99 Lang et al had similar results, making a definitive diagnosis in 88% of Bosniak IIF and III renal cysts using FNA and RMB. 100 The data supporting the role of RMS in complex cystic lesions is limited , but as experience increases and reliable immunohistochemical markers such as carbonic anhydrase-IX (CA-IX) emerge, 101 RMS in this cohort might play an increasing role. Tumor spillage has not been reported in recent studies, but remains an ongoing concern, as does the alteration in radiographic appearance that might occur after cyst sampling, which might complicate follow-up imaging.…”

“…114 Similarly, CA-IX testing of aspirated fluid from renal cysts has been shown to be useful in distinguishing between malignant and benign lesions. 101 There is increasing evidence that molecular profiling from proteomics or gene expression analyses can provide molecular fingerprints that may correlate with tumor histological subtype and aggressive potential. 65,107,115,116 For instance, gene expression microarrays have been used to classify patterns of gene expression characteristic of aggressive variants of RCC, 65 and these gene expression profiles have been shown to be concordant with final surgical pathology.…”