Intra-tumor genetic heterogeneity and mortality in head and neck cancer: analysis of data from the Cancer Genome Atlas.

BACKGROUND: Although the involvement of intra-tumor genetic heterogeneity in tumor progression, treatment resistance, and metastasis is established, genetic heterogeneity is seldom examined in clinical trials or practice. Many studies of heterogeneity have had prespecified markers for tumor subpopulations, limiting their generalizability, or have involved massive efforts such as separate analysis of hundreds of individual cells, limiting their clinical use. We recently developed a general measure of intra-tumor genetic heterogeneity based on whole-exome sequencing (WES) of bulk tumor DNA, called mutant-allele tumor heterogeneity (MATH). Here, we examine data collected as part of a large, multi-institutional study to validate this measure and determine whether intra-tumor heterogeneity is itself related to mortality. METHODS AND FINDINGS: Clinical and WES data were obtained from The Cancer Genome Atlas in October 2013 for 305 patients with head and neck squamous cell carcinoma (HNSCC), from 14 institutions. Initial pathologic diagnoses were between 1992 and 2011 (median, 2008). Median time to death for 131 deceased patients was 14 mo; median follow-up of living patients was 22 mo. Tumor MATH values were calculated from WES results. Despite the multiple head and neck tumor subsites and the variety of treatments, we found in this retrospective analysis a substantial relation of high MATH values to decreased overall survival (Cox proportional hazards analysis: hazard ratio for high/low heterogeneity, 2.2; 95% CI 1.4 to 3.3). This relation of intra-tumor heterogeneity to survival was not due to intra-tumor heterogeneity's associations with other clinical or molecular characteristics, including age, human papillomavirus status, tumor grade and TP53 mutation, and N classification. MATH improved prognostication over that provided by traditional clinical and molecular characteristics, maintained a significant relation to survival in multivariate analyses, and distinguished outcomes among patients having oral-cavity or laryngeal cancers even when standard disease staging was taken into account. Prospective studies, however, will be required before MATH can be used prognostically in clinical trials or practice. Such studies will need to examine homogeneously treated HNSCC at specific head and neck subsites, and determine the influence of cancer therapy on MATH values. Analysis of MATH and outcome in human-papillomavirus-positive oropharyngeal squamous cell carcinoma is particularly needed. CONCLUSIONS: To our knowledge this study is the first to combine data from hundreds of patients, treated at multiple institutions, to document a relation between intra-tumor heterogeneity and overall survival in any type of cancer. We suggest applying the simply calculated MATH metric of heterogeneity to prospective studies of HNSCC and other tumor types.

Association of Estrogen Receptor Alpha Expression With Survival in Oropharyngeal Cancer Following Chemoradiation Therapy.

BACKGROUND: Oropharyngeal squamous carcinoma (OPSC) continues to increase in incidence secondary to human papillomavirus (HPV) infection. Despite the good overall prognosis for these patients, treatment with chemoradiation is associated with morbidity and treatment failure. Better predictors for disease outcome are needed to guide de-intensification regimens. We hypothesized that estrogen receptor α (ERα), a prognostic biomarker in oncology with therapeutic implications, might have similar utility in OPSC. METHODS: To investigate associations among ERα and demographics, HPV status, and survival, we analyzed ERα mRNA expression of head and neck squamous carcinomas (HNSC) from The Cancer Genome Atlas (TCGA) and immunohistochemistry (IHC) of pretreatment biopsy specimens from an independent group of 215 OPSC patients subsequently treated with primary chemoradiation (OPSC-CR). Associations among variables were evaluated with Fisher exact tests and logistic regression; associations with survival were evaluated with log-rank tests and Cox proportional hazards regression. RESULTS: Among 515 patients in TCGA, ERα mRNA expression was highest in HPV-positive OPSC. High ERα mRNA expression was associated with improved survival among those receiving chemoradiation (hazard ratio adjusted for HPV status = 0.44, 95% confidence interval = 0.21 to 0.92). In OPSC-CR, ERα was positive by IHC in 51.6% of tumors and was associated with improved overall, disease-specific, progression-free, and relapse-free survival (log-rank tests: P < .001, P < .001, P = .002, P = .003, respectively); statistically significant associations of ERα positivity with improved survival were maintained after adjusting for clinical risk factors including HPV status. CONCLUSION: In two independent cohorts, ERα is a potential biomarker for improved survival that also may represent a therapeutic target in OPSC.

Staged Surgery for Advanced Thyroid Cancers: Safety and Oncologic Outcomes of Neural Monitored Surgery.

Objective Thyroidectomy with extensive multicompartment bilateral neck dissections for advanced-stage thyroid cancer may lead to increased risk of complications, including bilateral recurrent laryngeal nerve (RLN) paralysis and hypoparathyroidism. A planned staged approach derived from a detailed preoperative radiographic map is associated with a low complication profile. This study evaluates oncologic results and safety of neural monitored, staged thyroid cancer surgery for management of advanced thyroid cancer. Study Design Case series with chart review. Setting Tertiary care center. Subjects and Methods With institutional review board approval, 35 consecutive patients with advanced thyroid malignancy and extensive nodal disease managed with staged surgery between January 2004 and May 2013 by the senior author (G.W.R.) were identified, and the oncologic and surgical outcomes were reviewed. Results In total, 37.2% of patients had stage III or IV disease, with extrathyroidal extension in 71.4%, vascular invasion in 51.4%, and RLN invasion in 17% of patients. A total of 34% patients had positive lymph nodes in more than 5 nodal compartments; the average positive lymph node yield was 17, and extranodal extension was present in 51%. Three patients had RLN sacrifice, and there were no other cases of temporary or permanent RLN paralysis; permanent hypoparathyroidism and chyle leak occurred in one patient each. Locoregional recurrence occurred in 5.7% of patients after a 147-week mean follow-up. In patients with papillary thyroid carcinoma, median postoperative nonstimulated and stimulated thyroglobulin levels were 0.2 and 0.75 ng/mL, respectively. Conclusion A neural monitored, staged surgical approach was conducted without significant adverse events in this small sample and represents and effective alternative strategy option to simultaneous bilateral surgery in the management of thyroid cancer with extensive neck metastases.

Quantitative analysis of the effect of cell type and cellular differentiation on protective antigen binding to human target cells.

We quantitatively measured protective antigen (PA) binding to human cells targeted by anthrax lethal toxin (LT). Affinities were less than 50 nM for all cells, but differentiated cells (macrophages and neutrophils) had significantly increased PA binding and endothelial cells demonstrated the most binding. Combined with the function of such cells, this suggests that PA receptors interact with the extracellular matrix and that differentiation increases the number of PA-specific receptors, which supports previously observed differentiation-induced LT susceptibility. Our results quantifiably confirm that the generality of PA binding will complicate its use as a tumor targeting agent.

Impact of human papillomavirus on oropharyngeal cancer biology and response to therapy: implications for treatment.

Oropharyngeal squamous cell carcinoma (OPSCC) originating from human papillomavirus infection has emerged as a new entity in head and neck cancer, defining a subset of patients with distinct carcinogenesis, risk factor profiles, and clinical presentation that show markedly improved survival than patients with classic OPSCC. De-escalation of therapy and identification of relevant biomarkers to aid in patient selection are actively being investigated. This review addresses the implications of these findings in clinical care.