Surgical salvage of the oropharynx after failure of organ-sparing therapy

BACKGROUND

The purpose of this study was to evaluate the efficacy of salvage surgery for local recurrences of oropharyngeal squamous cell carcinoma (OPSCC) and identify predictors of survival.

METHODS

The authors reviewed 264 patients with OPSCC treated with radiation or chemoradiation identified retrospectively. Of the 77 patients that experienced recurrences, 37 had local or local and regional recurrences and were considered for salvage surgery.

RESULTS

Of the 37 patients with local or local and regional recurrence, 5 had unresectable disease whereas 3 refused surgery. The remainder underwent salvage surgery with 2-year and 5-year survival rates of 64.5% and 43.4%, respectively. A history of alcohol abuse and positive surgical margins were the only predictors of poorer overall survival (p < .05) after salvage surgery.

CONCLUSION

Surgical salvage of locoregional recurrences can be effective if wide resections are performed so that negative margins can be achieved.

Quantitative Studies of White Matter : I. Enzymes involved in glucose-6-phosphate metabolism

Total lipid and six enzymes closely related to the metabolism of glucose-6-phosphate have been measured in ten tracts of the rabbit. Lipid content appears to be a valid indicator of the degree of myelination. Heavily myelinated tracts have much larger amounts of glucose-6-phosphate dehydrogenase than lightly myelinated ones but there is no corresponding difference in 6-phosphogluconate dehydrogenase. In fact the ratios between the two enzymes were found to vary over a ninefold range. Hexokinase is found in largest amounts in tracts with relatively little lipid, and this tends to be true for phosphofructokinase as well. The fibrillar layer of olfactory bulb is exceptional with regard to both enzymes, and to glucose-6-phosphate dehydrogenase. The enzymes are present in amounts which are more than adequate to support glucose metabolism at a rate commensurate with the known rates of O₂ uptake by various tracts. The distribution of some of the enzymes is compatible with the notion that the nodes of Ranvier are regions of high metabolic activity. A simple algebraic relationship is found to hold fairly well for the distribution of four of the enzymes among the tracts.

Abstract 2007: Concurrent gene promoter hypermethylation and allele loss occurs infrequently in head and neck squamous cell carcinomas

Malignancies arise as a result of environmental insults that cause an accumulation of molecular changes in the genomes and epigenomes of the affected somatic cells. Numerous models have been described that outline the set of consequential alterations for different tumor types throughout carcinogenesis. The implication of Knudson's two-hit hypothesis for inactivation of tumor suppressor genes, with regards to the emerging field of integrative genomics, is that this gene silencing can be achieved through deletion of one allele and hypermethylation of the other. We aimed to characterize this process in the upper airway epithelium through an array-based molecular investigation of 19 head and neck squamous cell carcinomas (HNSCCs). We utilized a genome-wide integrated approach, combining data from DNA methylation arrays (&gt;1400 loci) with SNP-based resequencing (&gt;500K loci) copy number data, and a novel analytical approach involving model-based clustering methods. We found that while methylation and gene copy number were well-correlated for a number of loci, few tumor suppressors exhibited concomitant silencing alterations. In fact, of the commonly altered genes in this disease only CDKN2A possessed both hypermethylation and allele loss, and only at one locus for a minority of tumors (3/18). Three tumors also lacked one copy of the maintenance methyltransferase gene, DNMT1, and these samples had a lower average methylation across all loci measured than those with a normal copy number (P&lt;0.0001) at this site. Our results suggest that coordination of molecular mechanisms rarely occurs at single genes; however they may be linked through global regulatory processes affecting the patterns of coordinated alterations in order to control carcinogenic gene pathways. A thorough understanding of these alteration patterns and integration of such molecular processes are critical for the identification of cellular targets/biomarkers in HNSCC and for rational therapeutic administration.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 2007.

Bcl2 and human papilloma virus 16 as predictors of outcome following concurrent chemoradiation for advanced oropharyngeal cancer

PURPOSE

Oropharyngeal squamous cell carcinoma (OPSCC) associated with human papilloma virus (HPV) is rapidly growing in incidence. Despite better prognosis than OPSCC associated with traditional risk factors, treatment failure still occurs in a significant proportion of patients. We had identified the antiapoptotic protein Bcl2 as a marker for poor outcome in advanced OPSCC treated with concurrent chemoradiation. To determine whether Bcl2 and HPV together might further characterize treatment response, we examined whether the prognostic value of Bcl2 was independent of HPV status.

EXPERIMENTAL DESIGN

Pretreatment tumor biopsies from 68 OPSCC patients were tested for HPV by in situ hybridization and were immunostained for Bcl2 to evaluate relations with disease-free (DFS) and overall survival following platin-based concurrent chemoradiation. Median follow-up among surviving patients was 47 months (range, 10-131 months).

RESULTS

Bcl2 and HPV independently predicted DFS and overall survival. Hazard ratios (with 95% confidence interval) for positive versus negative status in bivariate Cox proportional hazard analysis of DFS were 6.1 (1.8-21) for Bcl2 and 0.11 (0.035-0.37) for HPV. Only 1 of 32 HPV-positive/Bcl2-negative tumors recurred. Pretreatment Bcl2 expression was specifically associated with distant metastasis; five of six distant metastases occurred in the <40% of patients whose primary tumors were Bcl2 positive.

CONCLUSIONS

Independent of HPV status, pretreatment Bcl2 expression identifies a subset of OPSCC patients having increased risk of treatment failure, particularly through distant metastasis, after concurrent chemoradiation. Considering HPV and Bcl2 together should help in devising better personalized treatments for OPSCC.

Genetic and epigenetic somatic alterations in head and neck squamous cell carcinomas are globally coordinated but not locally targeted

Background

Solid tumors, including head and neck squamous cell carcinomas (HNSCC), arise as a result of genetic and epigenetic alterations in a sustained stress environment. Little work has been done that simultaneously examines the spectrum of both types of changes in human tumors on a genome-wide scale and results so far have been limited and mixed. Since it has been hypothesized that epigenetic alterations may act by providing the second carcinogenic hit in gene silencing, we sought to identify genome-wide DNA copy number alterations and CpG dinucleotide methylation events and examine the global/local relationships between these types of alterations in HNSCC.

Methodology/Principal Findings

We have extended a prior analysis of 1,413 cancer-associated loci for epigenetic changes in HNSCC by integrating DNA copy number alterations, measured at 500,000 polymorphic loci, in a case series of 19 primary HNSCC tumors. We have previously demonstrated that local copy number does not bias methylation measurements in this array platform. Importantly, we found that the global pattern of copy number alterations in these tumors was significantly associated with tumor methylation profiles (p<0.002). However at the local level, gene promoter regions did not exhibit a correlation between copy number and methylation (lowest q = 0.3), and the spectrum of genes affected by each type of alteration was unique.

Conclusion/Significance

This work, using a novel and robust statistical approach demonstrates that, although a “second hit” mechanism is not likely the predominant mode of action for epigenetic dysregulation in cancer, the patterns of methylation events are associated with the patterns of allele loss. Our work further highlights the utility of integrative genomics approaches in exploring the driving somatic alterations in solid tumors.

Bcl-2 blocks cisplatin-induced apoptosis and predicts poor outcome following chemoradiation treatment in advanced oropharyngeal squamous cell carcinoma

PURPOSE

This study aimed to test the hypothesis that elevated expression of antiapoptotic Bcl-2 family proteins predicts a poor therapeutic response of oropharyngeal squamous cell carcinoma (OPSCC) to concurrent platinum-based chemoradiation therapy.

EXPERIMENTAL DESIGN

Levels of Bcl-2, Bcl-XL, and Bcl-w were determined and correlated with resistance to cisplatin in a large panel of cell lines derived from squamous cell carcinoma of the head and neck (HNSCC). Univariate and multivariate analyses were used to evaluate the relationship between Bcl-2 and Bcl-XL expression and disease-free survival following chemoradiation therapy in a uniformly treated cohort of patients with OPSCC.

RESULTS

In HNSCC cell lines, high endogenous Bcl-2 expression was associated with increased cisplatin resistance, and experimental overexpression of Bcl-2 promoted cisplatin resistance. In patients, tumors positive for Bcl-2 before treatment had greater risk of treatment failure (hazard ratio, 5.99; 95% confidence interval, 1.73-20.8; P=0.0014). In contrast, endogenous Bcl-XL showed no correlation either with cisplatin sensitivity in the cell line panel in vitro, or with risk of recurrence in vivo (hazard ratio, 1.28; 95% confidence interval, 0.39-4.19; P=0.68). Associations between Bcl-2 expression and other clinical characteristics did not account for the predictive value of Bcl-2.

CONCLUSIONS

Immunohistochemical assessment of Bcl-2 in pretreatment biopsy specimens can predict response of advanced OPSCC to concurrent platinum-based chemoradiation. As treatments targeting Bcl-2 and its family members become available, this immunohistochemical assessment could help personalize therapy by identifying a subpopulation of patients with a poor prognosis who might benefit from such treatments.

HPV-16 infection predicts treatment outcome in oropharyngeal squamous cell carcinoma

Objective: To determine if patients with human papillomavirus (HPV)-positive oropharyngeal squamous cell carcinoma (OPSCC) treated with chemoradiation have improved outcomes.

Study Design: A retrospective search was used to identify patients with OPSCC treated with concurrent chemoradiation. Pretreatment biopsy specimens were tested for HPV-16 infection and p16 expression.

Methods: Forty-four patients with OPSCC treated with concurrent chemotherapy and intensity-modulated radiation therapy were identified. Eligibility criteria included a minimum two years of follow-up, or biopsy-proven recurrence. In situ hybridization was applied to archival tumor specimens, with HPV-16-positive status defined as positive staining of tumor cell nuclei. p16 expression was assessed by immunohistochemistry.

Results: Twenty-seven tumors (61%) were positive for HPV-16 and 29 tumors (66%) expressed p16. HPV-16 infection was highly correlated with p16 expression ( P < 10−7). Three-year disease-free and overall survival for all patients was 66 percent and 79 percent respectively. Patients with tumors infected with HPV-16 had improved overall (OS) and disease-free survival (DFS) after chemoradiation (OS: hazard ratio [HR] = 0.21, P = 0.01; DFS: HR = 0.30, P = 0.02).

Conclusion: Patients with OPSCC tumors that are infected with HPV-16 have improved survival after treatment with concurrent chemoradiation.

A comparative study in ancestral range reconstruction methods: retracing the uncertain histories of insular lineages

Island systems have long been useful models for understanding lineage diversification in a geographic context, especially pertaining to the importance of dispersal in the origin of new clades. Here we use a well-resolved phylogeny of the flowering plant genus Cyrtandra (Gesneriaceae) from the Pacific Islands to compare four methods of inferring ancestral geographic ranges in islands: two developed for character-state reconstruction that allow only single-island ranges and do not explicitly associate speciation with range evolution (Fitch parsimony [FP; parsimony-based] and stochastic mapping [SM; likelihood-based]) and two methods developed specifically for ancestral range reconstruction, in which widespread ranges (spanning islands) are integral to inferences about speciation scenarios (dispersal-vicariance analysis [DIVA; parsimony-based] and dispersal-extinction-cladogenesis [DEC; likelihood-based]). The methods yield conflicting results, which we interpret in light of their respective assumptions. FP exhibits the least power to unequivocally reconstruct ranges, likely due to a combination of having flat (uninformative) transition costs and not using branch length information. SM reconstructions generally agree with a prior hypothesis about dispersal-driven speciation across the Pacific, despite the conceptual mismatch between its character-based model and this mode of range evolution. In contrast with narrow extant ranges for species of Cyrtandra, DIVA reconstructs broad ancestral ranges at many nodes. DIVA results also conflict with geological information on island ages; we attribute these conflicts to the parsimony criterion not considering branch lengths or time, as well as vicariance being the sole means of divergence for widespread ancestors. DEC analyses incorporated geological information on island ages and allowed prior hypotheses about range size and dispersal rates to be evaluated in a likelihood framework and gave more nuanced inferences about range evolution and the geography of speciation than other methods tested. However, ancestral ranges at several nodes could not be conclusively resolved, due possibly to uncertainty in the phylogeny or the relative complexity of the underlying model. Of the methods tested, SM and DEC both converge on plausible hypotheses for area range histories in Cyrtandra, due in part to the consideration of branch lengths and/or timing of events. We suggest that DEC model-based methods for ancestral range inference could be improved by adopting a Bayesian SM approach, in which stochastic sampling of complete geographic histories could be integrated over alternative phylogenetic topologies. Likelihood-based estimates of ancestral ranges for Cyrtandra suggest a major dispersal route into the Pacific through the islands of Fiji and Samoa, motivating future biogeographic investigation of this poorly known region.

Running biomechanics: shorter heels, better economy

Better running economy (i.e. a lower rate of energy consumption at a given speed) is correlated with superior distance running performance. There is substantial variation in running economy, even among elite runners. This variation might be due to variation in the storage and reutilization of elastic energy in tendons. Using a simple musculoskeletal model, it was predicted that the amount of energy stored in a tendon during a given movement depends more critically on moment arm than on mechanical properties of the tendon, with the amount of stored energy increasing as the moment arm gets smaller. Assuming a link between elastic energy reutilization and overall metabolic cost of running, a smaller moment arm should therefore be associated with superior running economy. This prediction was confirmed experimentally in a group of 15 highly trained runners. The moment arm of the Achilles tendon was determined from standardized photographs of the ankle, using the position of anatomical landmarks. Running economy was measured as the rate of metabolic energy consumption during level treadmill running at a speed of 16 km h(-1). A strong correlation was found between the moment arm of the Achilles tendon and running economy. Smaller muscle moment arms correlated with lower rates of metabolic energy consumption (r(2)=0.75, P<0.001).

A phase II study of gefitinib in patients with advanced thyroid cancer

OBJECTIVE

To determine the efficacy of gefitinib in patients with advanced thyroid cancer.

DESIGN

In this open-label phase II trial, 27 patients with radioiodine-refractory, locally advanced, or metastatic thyroid cancer were treated with 250 mg of daily gefitinib. Histologic subtypes included papillary (41%), follicular (22%), anaplastic (19%), medullary (15%), and Hürthle cell carcinomas (4%). The primary endpoint was overall response rate. Secondary endpoints were toxicity, progression-free survival (PFS), and overall survival (OS).

MAIN OUTCOMES

There were no objective responses among the 25 patients evaluated. After 3, 6, and 12 months of treatment, 48%, 24%, and 12% of patients had stable disease (SD), respectively. Median PFS and OS were 3.7 and 17.5 months, respectively. Five patients with SD had a decrease in thyroglobulin (Tg) to <90% of baseline that was maintained for at least 3 months.

CONCLUSIONS

Although gefitinib therapy did not result in any tumor responses, 32% of patients had reductions in tumor volume that did not meet criteria for partial response rate. Along with falling Tg levels and prolonged SD in a subset of patients, this may indicate biologic activity.

Incidence and Ecology of Blackberry yellow vein associated virus

Symptoms of leaf vein yellowing and bush decline in blackberry were attributed to infection by a novel crinivirus named Blackberry yellow vein associated virus (BYVaV). The disease is an emerging threat to blackberry production because it can cause substantial yield loss. The objective of this study was to identify the source and means of spread of BYVaV. A survey of blackberry plants for BYVaV from wild, cultivated, and nursery stocks was conducted. Insect traps and healthy blackberry sentinel plants were placed among symptomatic plants in a production field throughout two growing seasons to monitor the occurrence of potential vectors and virus spread. Virus indicator plants were grafted with BYVaV-infected blackberry because this virus was latent in some blackberry cultivars, but indicator plants failed to express symptoms when infected with BYVaV. Reverse-transcription polymerase chain reaction detection revealed the occurrence of BYVaV in blackberry nurseries in the United States, in production fields in Arkansas, South Carolina, and North Carolina, and in wild blackberry populations in Arkansas. Whiteflies (Trialeurodes packardii and T. ruborum), potential vectors of BYVaV, were observed on sticky traps placed in blackberry fields and were found colonizing blackberry plants; however, transmission studies failed to produce whitefly-mediated transmission of BYVaV. Further understanding of the disease etiology is needed to devise viable management strategies for this disease.