Clinical Impact of a Novel MicroRNA Chemo-Sensitivity Predictor in Gastrooesophageal Cancer

BACKGROUND

miRNAs might be potentially useful biomarkers for prediction of response to chemotherapeutic agents, radiotherapy and survival. The aim of this retrospective study was to validate miRNA response predictors in a cohort of patients with gastrooesophageal cancer in order to predict overall survival (OS) and disease-specific survival (DSS).

MATERIAL AND METHODS

The study population encompassed 53 patients treated with curative intend for loco-regional gastrooesophageal cancer. miRNA expression was quantified from pre-therapeutic and diagnostic, formalin-fixed, paraffin embedded tumour specimens using Affymetrix GeneChip miRNA 1.0 Array. Based on growth inhibition of the NCI60 panel in the presence of cisplatin, epirubicine and capecitabine, a miRNA based response predictor was developed. The Cox proportional hazards model was applied to assess the correlations of the response predictor with OS and DSS.

RESULTS

A univariate analysis demonstrated a statistical significant improvement of OS for patients who had undergone surgical resection with prediction scores above the median prediction score (HR: 0.41 (95% CI: 0.17-0.96). Adjusting for surgery and stage, this predictor was identified to be independently associated with both OS (HR: 0.37 (95% CI: 0.16-0.87)) and DSS (HR: 0.32 (0.12-0.87)).

CONCLUSION

The miRNA profile predictive for sensitivity to cisplatin, epirubicine and capecitabine was shown to be independently associated with OS and DSS in patients with gastrooesophageal cancer.

Hypoxia-regulated MicroRNAs in Gastroesophageal Cancer

BACKGROUND/AIM

The present study aimed to identify hypoxia-regulated microRNAs (HRMs) in vitro and investigate the clinical role of candidate HRMs in patients with gastroesophageal cancer (GEC).

MATERIALS AND METHODS

microRNA expression changes induced by hypoxia in human GEC cell lines were measured with microarrays and validated by quantitative real-time polymerase chain reaction. Candidate HRMs were measured in pre-therapeutic tumor samples from 195 patients with GEC.

RESULTS

Expression of miR-210 was shown to be significantly induced in esophageal squamous cell carcinoma (9.26-fold, p<0.001) and adenocarcinoma cell lines (4.95-fold, p<0.001) and miR-27a-star was significantly up-regulated in adenocarcinoma cell lines (4.79-fold, p=0.04). A weak but significant correlation between miR-210 expression and a 15-gene hypoxia signature was observed (Pearson r correlation: r=0.38, p<0.001). No significant associations of HRMs and clinical outcome in patients with GEC were identified.

CONCLUSION

This study supports the involvement of hypoxia on miRNAs in vitro and confirms the role of miR-210 as being a universal HRM.

Evaluation of miR-21 and miR-375 as prognostic biomarkers in esophageal cancer

BACKGROUND

MicroRNAs (miRNAs) have been associated with prognosis in esophageal cancer, suggesting a role for miRNAs to help guide treatment decisions. Especially, miR-21 and miR-375 have been investigated as prognostic biomarkers. The aim of this study was to evaluate the prognostic potential of miR-21 and miR-375 in primary esophageal squamous cell carcinomas (ESCC) and esophagogastric adenocarcinomas (EAC).

MATERIAL AND METHODS

Pre-therapeutic tumor specimens from 195 patients with loco-regional esophageal cancer treated with neoadjuvant or definitive chemoradiotherapy or perioperative chemotherapy were analyzed. Expression levels of miR-21 and miR-375 were quantified using Affymetrix GeneChip miRNA 1.0 Array. The Cox proportional hazards model was used to assess the correlation of miR-21 and miR-375 with disease-specific survival (DSS) and overall survival (OS). Forest plots were performed to evaluate the prognostic impact of miR-21 and miR-375 in the present study and previously published reports.

RESULTS

In ESCC, patients with miR-21 expression levels above median showed a trend towards poorer DSS and OS. When dividing miR-21 expression by tertiles, high levels of miR-21 significantly correlated with shortened DSS [HR 1.76 (95% CI 1.05-2.97) but not OS. Similarly for EAC, a significant association between miR-21 expression above median and DSS was observed [HR 3.37 (95% CI 1.41-8.05)], in addition to a trend towards poorer OS for patients with miR-21 expression above median. Multivariate analyses identified miR-21 as an independent prognostic marker for DSS in EAC [HR 3.52 (95% CI 1.06-11.69)]. High miR-375 was not correlated with improved prognosis in either histology. However, Forest plots demonstrated that both miR-21 and miR-375 were of prognostic impact in ESCC.

CONCLUSION

In this study, miR-21 was identified as an independent prognostic biomarker for DSS in patients with EAC whereas miR-21 failed to show independent prognostic significance in ESCC. High miR-375 was not associated with enhanced survival in either histology.

Dosimetric evaluation of anatomical changes during treatment to identify criteria for adaptive radiotherapy in oesophageal cancer patients

BACKGROUND

Some oesophageal cancer patients undergoing chemotherapy and concomitant radiotherapy (chemoRT) show large interfractional anatomical changes during treatment. These changes may modify the dose delivered to the target and organs at risk (OARs). The aim of the presenwt study was to investigate the dosimetric consequences of anatomical changes during treatment to obtain criteria for an adaptive RT decision support system.

MATERIAL AND METHODS

Twenty-nine patients were treated with chemoRT for oesophageal and gastro-oesophageal junction cancer and set up according to daily cone beam computed tomography (CBCTs) scans. All patients had an additional replanning CT scan at median fraction number 10 (9-14), which was deformably registered to the original planning CT. Gross tumour volumes (GTVs), clinical target volumes (CTVs) and OARs were transferred to the additional CT and corrected by an exwperienced physician. Treatment plans were recalculated and dose to targets and OARs was evaluated. Treatment was adapted if the volume receiving 95% of the prescribed dose (V95%) coverage of CTV decreased > 1% or planning target volume (PTV) decreased by > 3%.

RESULTS

In total, nine adaptive events were observed: All nine were triggered by PTV V95% decrease > 3% [median 11% (5-41%)] and six of these were additionally triggered by CTV V95% decrease > 1% [median 5% (2-35%)]. The largest discrepancies were caused by interfractional baseline or amplitude shifts in diaphragm position (n = 5). Mediastinal (n = 6), oesophageal (n = 6) and bowel filling changes (n = 2) caused the remainder of the changes. For patients with dosimetric changes exceeding the adaptation limits, the discrepancies were confirmed by inspecting the daily CBCTs. In 31% of all patients, heart V30Gy increased more than 2% (maximum 5%). Only minor changes in lung dose or liver dose were seen.

CONCLUSION

Target coverage throughout the course of chemoRT treatment is compromised in some patients due to interfractional anatomical changes. Dose to the heart may increase as well.

The importance of reference gene analysis of formalin-fixed, paraffin-embedded samples from sarcoma patients - an often underestimated problem

OBJECTIVE

Reverse transcription quantitative real-time polymerase chain reaction is efficient for quantification of gene expression, but the choice of reference genes is of paramount importance as it is essential for correct interpretation of data. This is complicated by the fact that the materials often available are routinely collected formalin-fixed, paraffin-embedded (FFPE) samples in which the mRNA is known to be highly degraded. The purpose of this study was to investigate 22 potential reference genes in sarcoma FFPE samples and to study the variation in expression level within different samples taken from the same tumor and between different histologic types.

METHODS

Twenty-nine patients treated for sarcoma were enrolled. The samples encompassed 82 (FFPE) specimens. Extraction of total RNA from 7-μm FFPE sections was performed using a fully automated, bead-base RNA isolation procedure, and 22 potential reference genes were analyzed by reverse transcription quantitative real-time polymerase chain reaction. The stability of the genes was analyzed by RealTime Statminer. The intrasamples variation and the interclass correlation coefficients were calculated. The linear regression model was used to calculate the degradation of the mRNA over time.

RESULTS

The quality of RNA was sufficient for analysis in 84% of the samples. Recommended reference genes differed with histologic types. However, PPIA, SF3A1, and MRPL19 were stably expressed regardless of the histologic type included. The variation in ∆Cq value for samples from the same patients was similar to the variation between patients. It was possible to compensate for the time-dependent degradation of the mRNA when normalization was made using the selected reference genes.

CONCLUSION

PPIA, SF3A1, and MRPL19 are suitable reference genes for normalization in gene expression studies of FFPE samples from sarcoma regardless of the histology.

PET imaging of tumor hypoxia using 18F-labeled pimonidazole

BACKGROUND

Tumor hypoxia contributes to loco-regional failure, and for optimal treatment planning, knowledge about tumor hypoxia in individual patients is required. Nitroimidazole-based tracers, which are retained in hypoxic cells, allow PET-based assessment of tumor hypoxia, but current tracers are characterized by slow tracer retention and clearance, resulting in low inter-tissue contrast. Pimonidazole is an immune detectable hypoxia marker widely used for detection of hypoxia in tumor samples. Pimonidazole has excellent chemical properties for hypoxia imaging, but labeling for non- invasive assay has not been attempted. Here we labeled pimonidazole with (18)F ([(18)F]FPIMO).

MATERIAL AND METHODS

[(18)F]FPIMO was produced by fluorination of 1-[2-O-tosyl-3-(2-nitroimidazole-1-yl)-propyl]-piperidine, which resulted in two isomeric interchangeable forms (named "5" and "6") with a radiochemical purity of 91-100%. [(18)F]FPIMO was tested by incubation of two different tumor cell lines at high and low oxygen levels. [(18)F]FPIMO was also administered to tumor-bearing mice and tracer retention in tumors, non-hypoxic reference tissues and tissues involved in drug metabolism/clearance was evaluated by various techniques.

RESULTS AND CONCLUSIONS

Retention of [(18)F]FPIMO was strongly hypoxia-driven in vitro, but isomeric form "5" was particularly promising and reached impressive anoxic-to-oxic retention ratios of 36 and 102, in FaDuDD and SiHa cells, respectively, following three hours of tracer incubation. This was equal to or higher than ratios measured using the established hypoxia tracer [(18)F]FAZA. [(18)F]FPIMO also accumulated in tumors grown in mice, and reached tumor levels that were two to six-fold higher than in muscle three hours post-administration. Furthermore, the intra-tumoral distribution of [(18)F]FPIMO (autoradiography) and unlabeled pimonidazole (immunohistochemistry) was largely identical. Nonetheless, [(18)F]FPIMO proved inferior to [(18)F]FAZA, since absolute tumor signal and intra-tumoral contrast was low, thus compromising PET imaging. Low tumor signal was coupled to extensive tracer accumulation in liver and kidneys, and analysis of blood metabolites revealed that [(18)F]FPIMO was metabolized rapidly, with little parent compound remaining 15 minutes post-administration. Ongoing work focuses on the possibility of labeling pimonidazole in different positions with (18)F to improve tracer stability in vivo.

Hypoxia-regulated gene expression and prognosis in loco-regional gastroesophageal cancer

Gastroesophageal cancers are heterogeneous diseases with a poor outcome. Prognostic and predictive factors are needed to improve patient survival. Hypoxia is an adverse prognostic factor and is associated with resistance to chemo- and radiotherapy in various cancers. However, knowledge on the impact of hypoxia in gastroesophageal cancer is limited. The aim of this study was to evaluate potential prognostic factors in terms of a subset of hypoxia-responsive genes and clinicopathological parameters in patients with gastroesophageal cancer.

MATERIAL AND METHODS

Ninety-five patients with loco-regional gastroesophageal cancer treated with curative intent were retrospectively analyzed. Based on formalin-fixed paraffin-embedded diagnostic biopsies gene expressions of 15 hypoxia-induced and pH-independent genes from a previously described hypoxia gene expression classifier was quantified. The prognostic impact was evaluated for overall survival (OS) and disease-specific survival (DSS). Uni- and multivariate Cox proportional hazards model was used to identify hypoxia-responsive gene expression and clinicopathological parameters as prognostic markers.

RESULTS

An unsupervised hierarchical clustering of hypoxia regulated genes showed two well-differentiated patient clusters: One cluster of tumors with high gene expression and another with low gene expression, indicating a more hypoxic genotype versus a less hypoxic genotype respectively. As the group of esophageal squamous cell carcinomas (ESCC) alone showed intra-group heterogeneity this group was ranked according to the gene expression of the 15 genes. The most hypoxic third showed a trend towards a poorer outcome in terms of OS [HR = 0.48 (CI 0.21-1.07), p = 0.07] and DSS [HR = 0.48 (CI 0.18-1.24), p = 0.13]. Treatment response was identified as an independent prognostic factor for DSS in the group of ESCC [HR = 0.21 (CI 0.05-0.95), p = 0.04].

CONCLUSION

Gene expression analysis of 15 hypoxia-responsive genes was identified as a promising prognostic marker in patients with ESCC. Further studies confirming these results in larger patient cohorts are needed.

Advanced hepatocellular carcinoma in adolescence associated with congenital cholestasis: a case description

This case describes the clinical course and treatment of a 17-year-old male patient with advanced hepatocellular carcinoma (HCC) arising in a non-cirrhotic liver. The disease was thought to be caused by a congenital cholestatic syndrome associated with intermittent oedema in childhood, resembling the rare Aagenaes syndrome. Treatment choices in advanced HCC arising in adolescence are discussed.

PET hypoxia imaging with FAZA: reproducibility at baseline and during fractionated radiotherapy in tumour-bearing mice

PURPOSE

Tumour hypoxia is linked to treatment resistance. Positron emission tomography (PET) using hypoxia tracers such as fluoroazomycin arabinoside (FAZA) may allow identification of patients with hypoxic tumours and the monitoring of the efficacy of hypoxia-targeting treatment. Since hypoxia PET is characterized by poor image contrast, and tumour hypoxia undergoes spontaneous changes and is affected by therapy, it remains unclear to what extent PET scans are reproducible. Tumour-bearing mice are valuable in the validation of hypoxia PET, but identification of a reliable reference tissue value (blood sample or image-derived muscle value) for repeated scans may be difficult due to the small size of the animal or absence of anatomical information (pure PET). Here tumour hypoxia was monitored over time using repeated PET scans in individual tumour-bearing mice before and during fractionated radiotherapy.

METHODS

Mice bearing human SiHa cervix tumour xenografts underwent a PET scan 3 h following injection of FAZA on two consecutive days before initiation of treatment (baseline) and again following irradiation with four and ten fractions of 2.5 Gy. On the last scan day, mice were given an intraperitoneal injection of pimonidazole (hypoxia marker), tumours were collected and the intratumoral distribution of FAZA (autoradiography) and hypoxia (pimonidazole immunohistology) were determined in cryosections.

RESULTS

Tissue section analysis revealed that the intratumoral distribution of FAZA was strongly correlated with the regional density of hypoxic (pimonidazole-positive) cells, even when necrosis was present, suggesting that FAZA PET provides a reliable measure of tumour hypoxia at the time of the scan. PET-based quantification of tumour tracer uptake relative to injected dose showed excellent reproducibility at baseline, whereas normalization using an image-derived nonhypoxic reference tissue (muscle) proved highly unreliable since a valid and reliable reference value could not be determined. The intratumoral distribution of tracer was stable at baseline as shown by a voxel-by-voxel comparison of the two scans (R = 0.82, range 0.72-0.90). During treatment, overall tracer retention changed in individual mice, but there was no evidence of general reoxygenation.

CONCLUSION

Hypoxia PET scans are quantitatively correct and highly reproducible in tumour-bearing mice. Preclinical hypoxia PET is therefore a valuable and reliable tool for the development of strategies that target or modify hypoxia.

FAZA PET/CT hypoxia imaging in patients with squamous cell carcinoma of the head and neck treated with radiotherapy: results from the DAHANCA 24 trial

PURPOSE

Hypoxia is a cause of resistance to radiotherapy, especially in patients with head and neck squamous cell carcinoma (HNSCC). The purpose of this study was to evaluate (18)F-fluoroazomycin arabinoside (FAZA) positron emission tomography (PET)/computed tomography (CT) hypoxia imaging as a prognostic factor in HNSCC patients receiving radiotherapy.

MATERIAL AND METHODS

Forty patients with HNSCC treated with radiotherapy (66-76 Gy) were included. Static FAZA PET/CT imaging 2h post injection was conducted prior to irradiation. The hypoxic volume (HV) was delineated using a tumor-to-muscle value ≥ 1.4. In 13 patients, a repetitive FAZA PET/CT scan was conducted during the radiotherapy treatment.

RESULTS

A hypoxic volume could be identified in 25 (63%) of the 40 tumors. FAZA PET HV varied considerably with a range from 0.0 to 30.9 (median: 0.3) cm(3). The T(max)/M(med) ranged from 1.1 to 2.9 (median: 1.5). The distribution of hypoxia among the Human Papillomavirus (HPV) positive (12/16) and negative (13/24) tumors was not significant different. In the FAZA PET/CT scans performed during radiotherapy, hypoxia could be detected in six of the 13 patients. For these six patients the location of HV remained stable in location during radiotherapy treatment, though the size of the HV decreased. In 30 patients a positive correlation was detected between maximum FAZA uptake in the primary tumor and the lymph node. During a median follow up of 19 months a significant difference in disease free survival rate with 93% for patients with non hypoxic tumors and 60% for patients with hypoxic tumors could be detected.

CONCLUSION

This study emphasizes the role of FAZA PET/CT imaging as a suitable assay with prognostic potential for detection of hypoxia in HNSCC.

Characterization of positron emission tomography hypoxia tracer uptake and tissue oxygenation via electrochemical modeling

PURPOSE

Unique uptake and retention mechanisms of positron emission tomography (PET) hypoxia tracers make in vivo comparison between them challenging. Differences in imaged uptake of two common hypoxia radiotracers, [(61)Cu]Cu-ATSM and [(18)F]FMISO, were characterized via computational modeling to address these challenges.

MATERIALS AND METHODS

An electrochemical formalism describing bioreductive retention mechanisms of these tracers under steady-state conditions was adopted to relate time-averaged activity concentration to tissue partial oxygen tension (PO(2)), a common metric of hypoxia. Chemical equilibrium constants of product concentration to reactant concentration ratios were determined from free energy changes and reduction potentials of pertinent reactions reported in the literature. Resulting transformation functions between tracer uptake and PO(2) were compared against measured values in preclinical models. Additionally, calculated PO(2) distributions from imaged Cu-ATSM tracer activity concentrations of 12 head and neck squamous cell carcinoma (HNSCC) patients were validated against microelectrode PO(2) measurements in 69 HNSCC patients.

RESULTS

Both Cu-ASTM- and FMISO-modeled PO(2) transformation functions were in agreement with preclinical measured values within single-deviation confidence intervals. High correlation (r(2)=0.94, P<.05) was achieved between modeled PO(2) distributions and measured distributions in the patient populations. On average, microelectrode hypoxia thresholds (2.5 and 5.0 mmHg) corresponded to higher Cu-ATSM uptake [2.5 and 2.0 standardized uptake value (SUV)] and lower FMISO uptake (2.0 and 1.4 SUV). Uncertainties in the models were dominated by variations in the estimated specific activity and intracellular acidity.

CONCLUSIONS

Results indicated that the high dynamic range of Cu-ATSM uptake was representative of a narrow range of low oxygen tension whose values were dependent on microenvironment acidity, while FMISO uptake was representative of a wide range of PO(2) values that were independent of acidity. The models shed light on possible causes of these discrepancies, particularly as it pertains to image contrast, and may prove to be a useful methodology in quantifying relationships between other hypoxia tracers. Comprehensive and robust assessment of tumor hypoxia prior to as well as in response to therapy may be best provided by imaging of multiple hypoxia markers that provide complementary rather than interchangeable information.

Identifying hypoxia in human tumors: A correlation study between 18F-FMISO PET and the Eppendorf oxygen-sensitive electrode

INTRODUCTION

Polarographic oxygen-sensitive electrodes have demonstrated prognostic significance of hypoxia. However, its routine application is limited. (18)F-FMISO PET scans are a noninvasive approach, able to measure spatial and temporal changes in hypoxia. The aim of this study was to examine the association between measures of hypoxia defined by functional imaging and Eppendorf pO(2) electrodes.

MATERIALS AND METHODS

A total of 18 patients were included, nine squamous cell carcinoma of the head and neck and nine soft tissue tumors. The tumor volume was defined by CT, MRI, (18)FDG-PET or by clinical examination. The oxygenation status of the tumors was assessed using (18)F-FMISO PET imaging followed by Eppendorf pO(2) electrode measurements. Data were compared in a 'virtual voxel', resulting in individual histograms from each tumor.

RESULTS

The percentages of pO(2) ≤ 5 mmHg ranged from 9 to 94% (median 43%) for all 18 tumors. For (18)F-FMISO PET the T/M ratio ranged from 0.70 to 2.38 (median 1.13). Analyzing the virtual voxel histograms tumors could be categorized in three groups: Well oxygenated tumors with no hypoxia and concordance between the (18)F-FMISO data and the Eppendorf measurements, hypoxic tumors likewise with concordance between the two assays and inconclusive tumors with no concordance between the assays.

CONCLUSION

This study analyzed the relationship between (18)F-FMISO PET and Eppendorf pO(2) electrode measurements by use of a virtual voxel model. There was a spectrum of hypoxia among tumors that can be detected by both assays. However no correlation was observed, and in general tumors were more hypoxic based on Eppendorf pO(2) measurements as compared to (18)F-FMISO PET.

Daily cone-beam computed tomography used to determine tumour shrinkage and localisation in lung cancer patients

PURPOSE/OBJECTIVE

Daily Cone-beam computed tomography (CBCT) in room imaging is used to determine tumour shrinkage during a full radiotherapy (RT) course. In addition, relative interfractional tumour and lymph node motion is determined for each RT fraction.

MATERIAL AND METHODS

From November 2009 to March 2010, 20 consecutive lung cancer patients (14 NSCLC, 6 SCLC) were followed with daily CBCT during RT. The gross tumour volume for lung tumour (GTV-t) was visible in all daily CBCT scans and was delineated at the beginning, at the tenth and the 20th fraction, and at the end of treatment. Whenever visible, the gross tumour volume for lymph nodes (GTV-n) was also delineated. The GTV-t and GTV-n volumes were determined. All patients were setup according to an online bony anatomy match. Retrospectively, matching based on the internal target volume (ITV), the GTV-t or the GTV-n was performed.

RESULTS

In eight patients, we observed a significant GTV-t shrinkage (15-40%) from the planning CT until the last CBCT. Only five patients presented a significant shrinkage (21-37%) in the GTV-n. Using the daily CBCT imaging, it was found that the mean value of the difference between a setup using the skin tattoo and an online matching using the ITV was 7.3±2.9 mm (3D vector in the direction of ITV). The mean difference between the ITV and bony anatomy matching was 3.0±1.3 mm. Finally, the mean distance between the GTV-t and the GTV-N was 2.9±1.6 mm.

CONCLUSION

One third of all patients with lung cancer undergoing chemo-RT achieved significant tumour shrinkage from planning CT until the end of the radiotherapy. Differences in GTV-t and GTV-n motion was observed and matching using the ITV including both GTV-t and GTV-n is therefore preferable.

Reconstruction using free jejunal transfer after resection of cancer of the upper oesophagus

INTRODUCTION

Treatment of cancer of the upper part of the oesophagus is challenging. Even after intended curative treatment, less than half of the patients are alive after five years. This retrospective study evaluates all the patients who had the upper oesophagus reconstructed by use of a free jejunal transfer following cancer resection from February 2000 to May 2008 at the University Hospital of Aarhus.

MATERIAL AND METHODS

Twenty patients aged 46-75 years were included. In all 20 cases, the diagnosis was squamous cell carcinoma, T3 or T4. All patients suffered from severe dysphagia prior to surgery. The median follow-up time was 23 months at 31 January 2010.

RESULTS

No perioperative mortality was experienced. Thirteen patients are now dead; nine due to the cancer of the oesophagus and four due to other causes. The median survival time of the 13 diseased patients was 15.3 months. The seven patients who remain alive have a median survival time of 40.2 months. None of these patients have shown signs of recurrence of the oesophageal cancer. All the patients regained their capacity to swallow and thereby increased their quality of life. No complications were experienced in relation to the abdominal procedure of harvesting the jejunal transfer. Three patients developed a fistula and in one case this required minor surgery. Eight patients needed to have a dilatation procedure performed.

CONCLUSION

Reconstruction of the oesophagus with a free jejunal transfer is a suitable treatment for selected patients with cancer in the upper oesophagus.

Presence of intratumoral neutrophils is an independent prognostic factor in localized renal cell carcinoma

PURPOSE

We have previously demonstrated a significant negative impact of intratumoral neutrophils in metastatic renal cell carcinoma. This study assessed intratumoral neutrophils in localized clear cell renal cell carcinoma (RCC).

PATIENTS AND METHODS

The study comprised 121 consecutive patients who had a nephrectomy for localized RCC. Biomarkers (intratumoral CD8+, CD57+ immune cells, CD66b+ neutrophils, and carbonic anhydrase IX [CA IX]) were assessed by immunohistochemistry, and the relationship with clinical and histopathologic features and patient outcome was evaluated.

RESULTS

The intratumoral neutrophils ranged from zero to 289 cells/mm(2) tumor tissue. The presence of intratumoral neutrophils was statistically significantly associated with increasing tumor size, low hemoglobin, high creatinine, and CA IX < or = 85%. In multivariate analysis, the presence of intratumoral neutrophils (hazard ratio [HR], 3.0; 95% CI, 1.7 to 5.4; P < .0001), pT stage T3b/T4 (HR, 2.1; 95% CI, 1.2 to 3.6; P = .007), and low hemoglobin (HR, 1.8; 95% CI, 1.0 to 3.1; P = .03) were independent prognostic factors significantly associated with short recurrence-free survival. The presence of intratumoral neutrophils was also an independent prognostic factor for cancer-specific survival (HR, 3.5; 95% CI, 1.9 to 6.4; P < .0001) and overall survival (HR, 3.1; 95% CI, 1.9 to 5.0; P < .0001). Applying the prognostic value of intratumoral neutrophils to the Leibovich low-/intermediate-risk group (n = 78) showed a 5-year recurrence-free survival of 53% (95% CI, 34.6% to 71.8%; presence of intratumoral neutrophils) versus 87% (95% CI, 77.8% to 96.8%; absence of intratumoral neutrophils). The estimated concordance index was 0.74 using the Leibovich risk score and 0.80 when intratumoral neutrophils were added.

CONCLUSION

The presence of intratumoral neutrophils is a new, strong, independent prognostic factor for short recurrence-free, cancer-specific, and overall survival in localized clear cell RCC.

Intra-voxel heterogeneity influences the dose prescription for dose-painting with radiotherapy: a modelling study

The purpose of this study was to increase the potential of dose redistribution by incorporating estimates of oxygen heterogeneity within imaging voxels for optimal dose determination. Cellular oxygen tension (pO(2)) distributions were estimated for imaging-size-based voxels by solving oxygen diffusion-consumption equations around capillaries placed at random locations. The linear-quadratic model was used to determine cell survival in the voxels as a function of pO(2) and dose. The dose distribution across the tumour was optimized to yield minimal survival after 30 x 2 Gy fractions by redistributing the dose based on differences in oxygen levels. Eppendorf data of a series of 69 tumours were used as a surrogate of what might be expected from oxygen imaging datasets. Dose optimizations were performed both taking into account cellular heterogeneity in oxygenation within voxels and assuming a homogeneous cellular distribution of oxygen. Our simulations show that dose redistribution based on derived cellular oxygen distributions within voxels result in dose distributions that require less total dose to obtain the same degree of cell kill as dose distributions that were optimized with a model that considered voxels as homogeneous with respect to oxygen. Moderately hypoxic tumours are expected to gain most from dose redistribution. Incorporating cellular-based distributions of radiosensitivity into dose-planning algorithms theoretically improves the potential gains from dose redistribution algorithms.

Germline mutation in RNASEL predicts increased risk of head and neck, uterine cervix and breast cancer

The Background

Ribonuclease L (RNASEL), encoding the 2′-5′-oligoadenylate (2-5A)-dependent RNase L, is a key enzyme in the interferon induced antiviral and anti-proliferate pathway. Mutations in RNASEL segregate with the disease in prostate cancer families and specific genotypes are associated with an increased risk of prostate cancer.

Infection by human papillomavirus (HPV) is the major risk factor for uterine cervix cancer and for a subset of head and neck squamous cell carcinomas (HNSCC). HPV, Epstein Barr virus (EBV) and sequences from mouse mammary tumor virus (MMTV) have been detected in breast tumors, and the presence of integrated SV40 T/t antigen in breast carcinomas correlates with an aggressive phenotype and poor prognosis.

A genetic predisposition could explain why some viral infections persist and induce cancer, while others disappear spontaneously. This points at RNASEL as a strong susceptibility gene.

Methodology/Principal Findings

To evaluate the implication of an abnormal activity of RNase L in the onset and development of viral induced cancers, the study was initiated by searching for germline mutations in patients diagnosed with uterine cervix cancer. The rationale behind is that close to 100% of the cervix cancer patients have a persistent HPV infection, and if a defective RNase L were responsible for the lack of ability to clear the HPV infection, we would expect to find a wide spectrum of mutations in these patients, leading to a decreased RNase L activity. The HPV genotype was established in tumor DNA from 42 patients diagnosed with carcinoma of the uterine cervix and somatic tissue from these patients was analyzed for mutations by direct sequencing of all coding and regulatory regions of RNASEL. Fifteen mutations, including still uncharacterized, were identified. The genotype frequencies of selected single nucleotide polymorphisms (SNPs) established in the cervix cancer patients were compared between 382 patients with head and neck squamous cell carcinomas (HNSCC), 199 patients with primary unilateral breast cancer and 502 healthy Danish control individuals. We found that the genotype frequencies of only one of the 15 mutations, the yet uncharacterized 5′UTR mutation rs3738579 differed significantly between cancer patients and control individuals (P-value: 4.43×10⁻⁵).

Conclusion/Significance

In conclusion, we have discovered an increased risk, a heterozygous advantage and thereby a protective effect linked to the RNASEL SNP rs3738579. This effect is found for patients diagnosed with carcinoma of the uterine cervix, HNSCC, and breast cancer thus pointing at RNASEL as a general marker for cancer risk and not restricted to familial prostate cancer.