Affymetrix U133plus2 GeneChips were used to profile 59 head and neck squamous cell cancers. A hypoxia metagene was obtained by analysis of genes whose in vivo expression clustered with the expression of 10 well-known hypoxia-regulated genes (e.g., CA9, GLUT1, and VEGF). To minimize random aggregation, strongly correlated up-regulated genes appearing in >50% of clusters defined a signature comprising 99 genes, of which 27% were previously known to be hypoxia associated. The median RNA expression of the 99 genes in the signature was an independent prognostic factor for recurrence-free survival in a publicly available head and neck cancer data set, outdoing the original intrinsic classifier. In a published breast cancer series, the hypoxia signature was a significant prognostic factor for overall survival independent of clinicopathologic risk factors and a trained profile. The work highlights the validity and potential of using data from analysis of in vitro stress pathways for deriving a biological metagene/gene signature in vivo. [Cancer Res 2007;67(7):3441–9]
Here we describe the expression and function of a HIF-1-regulated protein pyruvate dehydrogenase kinase-1 (PDK-1) in head and neck squamous cancer (HNSCC). Using RNAi to downregulate hypoxia-inducible PDK-1, we found that lactate and pyruvate excretion after 16–48 h of hypoxia was suppressed to normoxic levels. This indicates that PDK-1 plays an important role in maintaining glycolysis. Knockdown had no effect on proliferation or survival under hypoxia. The immunohistochemical expression of PDK-1 was assessed in 140 cases of HNSCC. PDK-1 expression was not expressed in normal tissues but was upregulated in HNSCC and found to be predominantly cytoplasmic with occasional strong focal nuclear expression. It was strongly related to poor outcome (P=0.005 split by median). These results indicate that HIF regulation of PDK-1 has a key role in maintaining lactate production in human cancer and that the investigation of PDK-1 inhibitors should be investigated for antitumour effects.
Objectives: We assessed the expression and the prognostic role of lactate dehydrogenase 5 (LDH5, the major LDH isoenzyme involved in anaerobic glycolysis) in patients with squamous cell head and neck cancer (SCHNC). Methods: LDH5 was assessed immunohistochemically in whole tissue sections from 141 patients with SCHNC. Of these, 102 were subjected to surgery with (90 patients) or without (12 patients) postoperative radiotherapy (group A), while 39 patients were treated with radical radiotherapy (group B). Results: Mixed nuclear/cytoplasmic LDH5 expression was detected in 72.5% of group A and 61.5% of group B patients. This was significantly related to T4-stage (p = 0.04) and hypoxia-inducible factor-1α (HIF-1α) expression (p = 0.002). In group A, high LDH5 was linked with poorer distant metastasis-free survival (p = 0.01) and disease-specific overall survival (OS; p = 0.009). In multivariate analysis, LDH5 (p = 0.002) and HIF-1α (p = 0.01) were independently linked with distant metastasis. LDH5 was also linked with death events (p = 0.005). In group B, high LDH5 expression was significantly associated with poorer local relapse-free survival (p = 0.009) and OS (p = 0.01). In multivariate analysis, only T stage was a significant predictor of death events (p = 0.04). Conclusions: LDH5 is highly expressed in SCHNC and is linked with local relapse, survival and distant metastasis, suggesting that LDH5 is a marker of radioresistance and a target for therapeutic interventions.
The use of transoral robotic surgery (TORS) and laser microsurgery (TLM) in the diagnosis and identification of the site of the unknown primary has become increasingly common. This systematic review and meta-analysis aims to assess the use and efficacy of TORS and TLM for this indication. Systematic review and meta-analysis of studies employing TORS or TLM in diagnosis of the unknown primary tumor site in patients with cervical nodal metastases of squamous cell origin. MEDLINE, EMBASE and CINHAL were searched from inception to July 2018 for all studies that used TORS and or TLM in identifying the unknown primary. 251 studies were identified, of which 21 were eligible for inclusion. The primary tumour was identified by TORS/TLM in 78% of patients (433 out of 556). Tongue base mucosectomy (TBM) identified the primary in 222 of 427 cases (53%). In patients with negative physical examination, diagnostic imaging and PETCT, TBM identified the primary in 64% (95% CI 50, 79) cases. In patients who had negative CT/MRI imaging, negative PETCT and negative EUA and tonsillectomy, TBM identified a tongue base primary in 78% (95% CI 41, 92) cases. Haemorrhage, the commonest complication, was reported in 4.9% cases. Mean length of stay varied between 1.4 and 6.3 days. Tongue base mucosectomy, performed by TORS or TLM, is highly efficacious in identifying the unknown primary in the head and neck region.
Overexpression and mutation of epidermal growth factor receptors (EGFR) have been shown to be important in the prognosis of several cancers, including head and neck cancers. However, our inability to define the activation status of these and other receptors limits our ability to assess the importance of these pathways and to exploit effectively new molecularly targeted treatments directed at their catalytic activities. Here we describe the use of automated, high-throughput fluorescence lifetime imaging microscopy to measure EGFR autophosphorylation status by fluorescence resonance energy transfer (FRET) in head and neck tumors. We have correlated FRET efficiency with the clinical and survival data. The results from head and neck arrays show that high FRET efficiency is correlated with worsening disease-free survival but not with overall survival. This powerful tool could be exploited as a new independent quantitative prognostic factor in clinical decisions and cancer management. (Cancer Res 2006; 66(5): 2834-43)