Abstract
Context
Current guidelines do not consistently recommend imaging beyond the head and neck region in succinate dehydrogenase subunit D (SDHD) mutation carriers as long as catecholamine ...metabolite levels are within the reference range.
Participants
We report a series of 10 patients carrying pathogenic variants in the SDHD gene from five tertiary referral centers for paraganglioma (PGL) in the Netherlands, who presented with a sympathetic PGL (sPGL), pheochromocytoma (PHEO), or metastases outside the head and neck region in the absence of excessive catecholamine production. Two of six patients with a biochemically silent sPGL/PHEO developed metastatic disease. Additionally, four patients were found to have metastases outside the head and neck region from head and neck PGL. The average interval between the initial diagnosis and discovery of the silent lesions was 10 (range, 0 to 32) years.
Conclusions
The absence of excessive catecholamine production does not exclude the presence of manifestations of SDHD outside the head and neck region. These findings suggest that a more extensive imaging strategy in SDHD mutation carriers may be warranted for detection of biochemically silent lesions.
Ten SDHD patients developed biochemically silent sympathetic paraganglioma, pheochromocytoma, or metastases. Intensified imaging may be warranted irrespective of hormonal activity in SDHD patients.
Abstract Background and purpose In a phase III trial in patients with advanced stage laryngeal carcinoma comparing ARCON (accelerated radiotherapy with carbogen breathing and nicotinamide) to ...accelerated radiotherapy alone (AR) the prognostic and predictive value of CAIX, a hypoxia-associated protein, was investigated. Material and methods 261 Paraffin embedded tumor biopsies and 79 fresh frozen biopsies from patients entered in the trial were immunohistochemically stained for CAIX. CAIX-fraction and CAIX expression pattern were related to tumor control and patient survival. Results Low CAIX-fraction was prognostic for worse regional control and overall survival in patients treated with AR. Patients with a low CAIX-fraction treated with ARCON had better regional control and metastasis-free survival compared to AR (RC 97% vs 71%, p < 0.01 and MFS 92% vs 69%, p = 0.06). Patients with a perinecrotic CAIX staining pattern had a significantly worse local control, metastasis-free and overall survival compared to patients with a diffuse pattern (65% vs 84%, p = 0.01, 70% vs 96%, p < 0.01 and 42% vs 71%, p < 0.01 respectively), and this could not be improved with ARCON. After multivariate analysis CAIX pattern and N-stage emerged as significant predictors for metastasis-free survival and overall survival. Conclusions ARCON improves regional control and metastasis-free survival only in patients with low CAIX expression. The different patterns of CAIX expression suggest different mechanisms of upregulation and have important prognostic value.
Abstract Tumour hypoxia as driving force in tumour progression and treatment resistance has been well established. Assessment of oxygenation status of tumours may provide important prognostic ...information and improve selection of patients for treatment. In this study, a large homogenous group of 103 laryngeal carcinomas has been investigated in the presence of hypoxia by pimonidazole binding and the usefulness of Carbonic anhydrase IX (CA-IX) and vascular parameters as surrogate markers of hypoxia. These parameters are further related to clinical and biological characteristics. One hundred and three patients with T2–T4 larynx carcinoma were included. They were given the hypoxia marker pimonidazole intravenously (i.v.) 2 h prior to taking a biopsy. Expression of all the parameters was examined by immunohistochemistry, excluding large necrotic areas. Among tumours a large variation in pimonidazole positivity (hypoxic fraction based on pimonidazole, HFpimo) (range 0–19%) and CA-IX expression (hypoxic fraction based on CA-IX staining, HFCA-IX) (range 0–34%) was observed. In 67% of the tumours, hypoxia involved ⩾1% of the viable tumour area. HFpimo and HFCA-IX correlated significantly albeit weak ( p = 0.04). Both parameters showed weak inverse correlations with the relative vascular area (RVA) ( p = 0.01). HFpimo was further associated with histopathological grade, with poorly differentiated tumours being more hypoxic. The fraction of the tumour area positive for both pimonidazole and CA-IX correlated significantly with N stage. From these results, it was concluded that CA-IX and RVA have only limited value for measuring hypoxia and are not as robust as pimonidazole, probably due to the influence of other factors in the microenvironment. A combination of staining patterns of exogenous and endogenous markers might give important additive information about tumour biology and behaviour.
Germline mutations in succinate dehydrogenase subunit B and D (
and
) are predisposed to hereditary paraganglioma (PGL) and pheochromocytoma (PHEO). The phenotype of pathogenic variants varies ...according to the causative gene. In this retrospective study, we estimate the mortality of a nationwide cohort of
variant carriers and that of a large cohort of
variant carriers and compare it to the mortality of a matched cohort of the general Dutch population. A total of 192
variant carriers and 232
variant carriers were included in this study. The Standard Mortality Ratio (SMR) for
mutation carriers was 1.89, increasing to 2.88 in carriers affected by PGL. For
variant carriers the SMR was 0.93 and 1.06 in affected carriers. Compared to the general population, mortality seems to be increased in
variant carriers, especially in those affected by PGL. In
variant carriers, the mortality is comparable to that of the general Dutch population, even if they are affected by PGL. This insight emphasizes the significance of DNA-testing in all PGL and PHEO patients, since different clinical risks may warrant gene-specific management strategies.
Summary Two mechanisms of radiotherapy resistance of major importance in head and neck cancer are tumour cell repopulation and hypoxia. Hypoxic tumour cells that retain their clonogenic potential can ...survive radiation treatment and lead to local recurrences. The aim of this study was to quantify this cellular population in a cohort of human head and neck carcinomas and to investigate the prognostic significance. The proliferation marker iododeoxyuridine (IdUrd) and the hypoxia marker pimonidazole were administered intravenously prior to biopsy taking in patients with stage II–IV squamous cell carcinoma of the head and neck. Triple immunohistochemical staining of blood vessels, IdUrd and pimonidazole was performed and co-localization of IdUrd and pimonidazole was quantitatively assessed by computerized image analysis. The results were related with treatment outcome. Thirty-nine biopsies were analyzed. Tumours exhibited different patterns of proliferation and hypoxia but generally the IdUrd signal was found in proximity to blood vessels whereas pimonidazole binding was predominantly at a distance from vessels. Overall, no correlations were found between proliferative activity and oxygenation status. The fraction of IdUrd-labelled cells positive for pimonidazole ranged from 0% to 16.7% with a mean of 2.4% indicating that proliferative activity was low in hypoxic areas and occurring mainly in the well-oxygenated tumour compartments. IdUrd positive cells in hypoxic areas made up only 0.09% of the total viable tumour cell mass. There were no associations between the magnitude of this cell population and local tumour control or survival. Co-localization between proliferating cells and hypoxia in head and neck carcinomas was quantified using an immunohistochemical triple staining technique combined with a computerized simultaneous analysis of multiple parameters. The proportion of cells proliferating under hypoxic conditions was small and no correlation with treatment outcome could be found.
Tumor cells undergo a variety of biological changes under sustained hypoxic conditions, allowing cells to survive and retain their clonogenic potential. The purpose of this study is to relate the ...expression of the hypoxia marker carbonic anhydrase 9 (CA9) to the uptake of iododeoxyuridine (IdUrd), a marker of proliferation, in head and neck squamous cell carcinomas. Colocalization of IdUrd and CA9 may identify an important subpopulation of tumor cells that might be responsible for repopulation and disease progression.
Expression of CA9, IdUrd labeling, and colocalization between IdUrd and CA9 was examined by immunohistochemistry in biopsies of head and neck squamous cell carcinomas. Biopsies were taken from 51 patients recruited between 1998 and 2001 after administration of the proliferation marker IdUrd.
A large variation was observed between the tumors in CA9 expression (range 0-39%), IdUrd labeling (range 0-81%), and colocalization between IdUrd and CA9 FId(CA9); range 0-53%. FId(CA9), the fraction of IdUrd-labeled cells positive for CA9, was highest at an intermediate distance from the blood vessels (100-150 microm). IdUrd labeling was higher in T4 carcinomas relative to lower stage tumors (P = 0.04). High FId(CA9) correlated with the worst disease-free survival rates (P = 0.04).
Colocalization between IdUrd labeling and CA9 expression was observed in head and neck squamous cell carcinomas, suggesting the presence of a population of tumor cells under intermediate hypoxic conditions which still has proliferative capacity. The size of this subpopulation may be indicative of tumor aggressiveness and is associated with the worst disease-free survival rates.
Purpose:
To quantify the physiologic status of human tumor cells in relation to the tumor vasculature.
Methods and Materials:
Fourteen tumors of 11 first-generation xenograft lines of human ...head-and-neck squamous cell carcinoma were injected with the hypoxic cell marker pimonidazole, the proliferation marker BrdUrd, and the perfusion marker Hoechst 33342. Consecutive tissue sections were processed with immunohistochemical methods and analyzed with image-analysis techniques.
Results:
Three different hypoxic patterns were found: patchy, ribbon-like, and mixed. An image-analysis method was developed to quantify these, and an elongation index (length/width) was calculated for hypoxia. The mean elongation indices ranged from 2.0 to 28.3 and showed a good correlation with the visual scoring of hypoxic patterns. Comparative analysis of hypoxic and proliferating cells in zones around the tumor vasculature showed the presence of both hypoxic and proliferating cells in all zones up to 250 μm from the vessels. The largest coexistence of hypoxic and proliferating cells seemed to occur at 50–100 μm from the vessels.
Conclusions:
The three hypoxic patterns could be quantified by an elongation index, which is an additional parameter that allows distinction of tumors with similar fractions of hypoxic cells. The analysis of hypoxic and proliferating cells as a function of distance from the tumor vasculature indicates that proliferation does occur also at low oxygen tensions.
Abstract Src family kinases (SFKs) have been implicated in resistance to both radiation and epidermal growth factor receptor (EGFR) inhibition. Therefore, we investigated whether inhibition of SFK ...through dasatinib (DSB) can enhance the effect of radiotherapy in two in vivo human head and neck squamous cell carcinoma (HNSCC) models. Response to DSB and/or radiotherapy was assessed with tumor growth delay assays in two HNSCC xenograft models, SCCNij153 and SCCNij202. Effects on EGFR signaling were evaluated withWestern blot analysis, and effects on DNA repair, hypoxia, and proliferation were investigated with immunohistochemistry. DSB and radiotherapy induced a significant growth delay in both HNSCC xenograft models, although to a lesser extent in SCCNij202. DSB did not inhibit phosphorylated protein kinase B (pAKT) or phosphorylated extracellular signal-regulated kinase 1/2 (pERK1/2) but did inhibit (phosphorylated) DNA-dependent protein kinase. Moreover, DSB reduced repair of radiation-induced DNA double-strand breaks as shown by an increase of p53-binding protein 1 (53BP1) staining 24 hours after radiation. This effect on DNA repair was only observed in the cell compartment where phosphorylated SFK (pSFK) was expressed: for SCCNij153 tumors in both normoxic and hypoxic areas and for SCCNij202 tumors only in hypoxic areas. No consistent effects of DSB on hypoxia or proliferation were observed. In conclusion, DSB enhances the effect of radiotherapy in vivo by inhibition of radiation-induced DNA repair and is a promising way to improve outcome in HNSCC patients.
Hypoxia is detected in most solid tumors and is associated with malignant progression and adverse treatment outcomes. However, the oxygenation status of malignant salivary gland tumors has not been ...previously studied. The aim of this study was to investigate the potential clinical relevance of hypoxia in this tumor type.
Twelve patients scheduled for surgical resection of a salivary gland tumor were preoperatively injected with the hypoxia marker pimonidazole and the proliferation marker iododeoxyuridine. Tissue samples of the dissected tumor were immunohistochemically stained for blood vessels, pimonidazole, carbonic anhydrase-IX, glucose transporters-1 and -3 (Glut-1, Glut-3), hypoxia-inducible factor-1alpha, iododeoxyuridine, and epidermal growth factor receptor. The tissue sections were quantitatively assessed by computerized image analysis.
The tissue material from 8 patients was of sufficient quality for quantitative analysis. All tumors were negative for pimonidazole binding, as well as for carbonic anhydrase-IX, Glut-1, Glut-3, and hypoxia-inducible factor-1alpha. The vascular density was high, with a median value of 285 mm(-2) (range, 209-546). The iododeoxyuridine-labeling index varied from <0.1% to 12.2% (median, 2.2%). Epidermal growth factor receptor expression levels were mostly moderate to high. In one-half of the cases, nuclear expression of epidermal growth factor receptor was observed.
The absence of detectable pimonidazole binding, as well as the lack of expression of hypoxia-associated proteins in all tumors, indicates that malignant salivary gland tumors are generally well oxygenated. It is unlikely that hypoxia is a relevant factor for their clinical behavior and treatment responsiveness.
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