Evaluation of the diagnostic accuracy of RT-PCR quantification of cytokeratin MRNA in the detection of sentinel lymph node invasion in oral and oropharyngeal squamous cell carcinoma: A comparison with immuno-histochemistry
ABSTRACT The main goal of sentinel lymph node (SLN) detection in head and neck squamous cell carcinomas is to limit neck dissections to pN+ cases only. However, intraoperative + diagnosis cannot be routinely done using the current gold standard, serial step sectioning with immunohistochemistry. Real-time quantitative reverse transcription-PCR (RT-PCR) is potentially compatible with intraoperative use, proving highly sensitive in detecting molecular markers. This study postoperatively assessed the accuracy of quantitative RT-PCR in staging patients from their SLN.
A combined analysis on the same SLN by serial step sectioning with immunohistochemistry and quantitative RT-PCR targeting cytokeratins 5, 14, and 17 was done in 18 consecutive patients with oral or oropharyngeal squamous cell carcinoma and 10 control subjects.
From 71 lymph nodes examined, mRNA levels (KRT) were linked to metastasis size for the three cytokeratins studied (Pearson correlation coefficient, r = 0.89, 0.73, and 0.77 for KRT 5, 14, and 17 respectively; P < 0.05). Histopathology-positive SLNs (macro- and micrometastases) showed higher mRNA values than negative SLNs for KRT 17 (P < 10(-4)) and KRT 14 (P < 10(-2)). KRT 5 showed nonsignificant results. KRT 17 seemed to be the most accurate marker for the diagnosis of micrometastases of a size >450 mum. Smaller micrometastases and isolated tumor cells did not provide results above the background level. Receiver operating characteristic curve analysis for KRT 17 identified a cutoff value where patient staging reached 100% specificity and sensitivity for macro- and micrometastases.
Quantitative RT-PCR for SLN staging in cN(0) patients with oral and oropharyngeal squamous cell carcinoma seems to be a promising approach.
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ABSTRACT: The therapeutic protocols for treatment of germinomas and non-germinomatous germ cell tumors (NGGCTs) are completely different, so it is important to distinguish pure germinomas from NGGCTs. As it can be difficult to diagnose by morphology alone, immunohisto-chemistry (IHC) has been widely used as an ancillary test to improve diagnostic accuracy. However, IHC has limitations due to the misinterpretation of results or the aberrant loss of immunoreactivity. However, real-time RT-PCR has certain advantages over IHC, including its quantitative nature. The aim of our study was to evaluate the usefulness of real-time RT-PCR on formalin-fixed paraffin-embedded (FFPE) tissue blocks for the diagnosis of germ cell tumors of the central nervous system. We selected eight markers of germ cell tumors using a literature search, and validated them using real-time RT-PCR. Among them, POU5F1, NANOG and TGFB2 were statistically significant (P=0.05) in multiple comparisons (MANOVA) of three groups (pure germinomas, mature teratomas and malignant germ cell tumors). Two-group (pure germinomas and NGGCTs) discriminant analysis achieved a 70.0% success rate in cross-validation. We concluded that real-time RT-PCR using FFPE tissue has adequate validating power comparable to IHC in the diagnosis of central nervous system germ cell tumors; therefore, when IHC is not available, not conclusive or not informative, RT-PCR is a potential alternative to a repeat biopsy.Molecular Medicine Reports 10/2012; 7(1). DOI:10.3892/mmr.2012.1144 · 1.48 Impact Factor
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ABSTRACT: BACKGROUND: An increasing proportion of oropharyngeal squamous cell carcinomas (OPSCCs) is associated with human papillomavirus (HPV) type 16 infection. Several authors have suggested that HR-HPV DNA could be used as a marker of metastases in cervical cancers. Although HPV16 DNA has been detected in neck lymph node (LN) metastases of HPV16-positive OPSCC, its significance remains controversial. Does this presence correlate to metastatic involvement or is it just the consequence of LN filter function? OBJECTIVES: This study aims to analyse the relationship between HPV16 detection in neck LNs of HPV16-positive OPSCC and their pathological status. STUDY DESIGN: HP16-viral load (VL) was quantified by real-time-polymerase-chain reaction in primary tumours and neck LNs, in 11 patients with HPV16-positive OPSCC and in three patients with HPV16-negative OPSCC. HPV16 in situ hybridisation and p16 immunohistochemistry were performed in all LNs. RESULTS: A total of 45 LN levels were assessed. HPV16 DNA was not identified in HPV16-negative OPSCC LNs. All metastatic LNs from HPV16-positive OPSCC had a high VL and the viral DNA was located within tumoural cells. Among 27 pathologically tumour-free LN (PTFLN) levels 16/27 had no detectable VL, whereas the VL was low or medium (<105copies/million cells) in 8/27 and high (>105copies/million cells) in 3/27 PTFLN. In the latter group, no metastatic cell was identified and the viral DNA was located in immune cells. CONCLUSION: HPV16 detection in LN is explained by its presence within either metastatic cells or immune cells. HPV16 detection in PTFLN is not necessarily correlated to occult LN metastases.Journal of clinical virology: the official publication of the Pan American Society for Clinical Virology 03/2013; DOI:10.1016/j.jcv.2013.02.009 · 3.47 Impact Factor
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ABSTRACT: Progression of oral carcinomas associates with aberrant activation and inactivation of molecules that work in established or unknown pathways. Although mucosa‑associated lymphoid tissue 1 (MALT1) expressed in normal oral epithelium is inactivated in the aggressive subset of carcinomas with worse prognosis, phenotypic changes of carcinoma cells upon the loss of expression is unknown. We performed a proteomic analysis to identify MALT1‑regulated proteins in oral carcinoma cells. Four different keratins were included in the ten most abundantly changed proteins. K8/18 were upregulated in MALT1 stably‑expressing carcinoma cells and K5/14 in MALT1‑marginal control cells. K8/18 upregulation and K5/14 downregulation were MALT1 dose‑dependent and observed in a series of oral carcinoma cells. MALT1 suppressed cell proliferation (0.52-fold, P<0.01) and its dominant-negative form stimulated it (1.33-fold, P<0.01). The decreased proliferation associated with reduction of cyclin D1, which was recovered by the short interfering RNA against MALT1. Taken together, loss of MALT1 expression alters keratin expression and enhances proliferation of carcinoma cells, and may progress oral carcinomas into the advanced state.International Journal of Oncology 06/2013; 43(3). DOI:10.3892/ijo.2013.1990 · 2.77 Impact Factor