The evolving landscape of salivary gland tumors.

Salivary gland cancers are a rare, histologically diverse group of tumors. They range from indolent to aggressive and can cause significant morbidity and mortality. Surgical resection remains the mainstay of treatment, but radiation and systemic therapy are also critical parts of the care paradigm. Given the rarity and heterogeneity of these cancers, they are best managed in a multidisciplinary program. In this review, the authors highlight standards of care as well as exciting new research for salivary gland cancers that will strive for better patient outcomes.

Circulating tumor DNA in advanced solid tumors: Clinical relevance and future directions.

The application of genomic profiling assays using plasma circulating tumor DNA (ctDNA) is rapidly evolving in the management of patients with advanced solid tumors. Diverse plasma ctDNA technologies in both commercial and academic laboratories are in routine or emerging use. The increasing integration of such testing to inform treatment decision making by oncology clinicians has complexities and challenges but holds significant potential to substantially improve patient outcomes. In this review, the authors discuss the current role of plasma ctDNA assays in oncology care and provide an overview of ongoing research that may inform real-world clinical applications in the near future.

Diagnostic performance of computed tomography features in detecting oropharyngeal squamous cell carcinoma extranodal extension.

OBJECTIVES: Accurate pre-treatment imaging determination of extranodal extension (ENE) could facilitate the selection of appropriate initial therapy for HPV-positive oropharyngeal squamous cell carcinoma (HPV + OPSCC). Small studies have associated 7 CT features with ENE with varied results and agreement. This article seeks to determine the replicable diagnostic performance of these CT features for ENE. METHODS: Five expert academic head/neck neuroradiologists from 5 institutions evaluate a single academic cancer center cohort of 75 consecutive HPV + OPSCC patients. In a web-based virtual laboratory for imaging research and education, the experts performed training on 7 published CT features associated with ENE and then independently identified the "single most (if any) suspicious" lymph node and presence/absence of each of the features. Inter-rater agreement was assessed using percentage agreement, Gwet's AC1, and Fleiss' kappa. Sensitivity, specificity, and positive and negative predictive values were calculated for each CT feature based on histologic ENE. RESULTS: All 5 raters identified the same node in 52 cases (69%). In 15 cases (20%), at least one rater selected a node and at least one rater did not. In 8 cases (11%), all raters selected a node, but at least one rater selected a different node. Percentage agreement and Gwet's AC1 coefficients were > 0.80 for lesion identification, matted/conglomerated nodes, and central necrosis. Fleiss' kappa was always < 0.6. CT sensitivity for histologically confirmed ENE ranged 0.18-0.94, specificity 0.41-0.88, PPV 0.26-0.36, and NPV 0.78-0.96. CONCLUSIONS: Previously described CT features appear to have poor reproducibility among expert head/neck neuroradiologists and poor predictive value for histologic ENE. KEY POINTS: • Previously described CT imaging features appear to have poor reproducibility among expert head and neck subspecialized neuroradiologists as well as poor predictive value for histologic ENE. • Although it may still be appropriate to comment on the presence or absence of these CT features in imaging reports, the evidence indicates that caution is warranted when incorporating these features into clinical decision-making regarding the likelihood of ENE.

Systemic and Targeted Therapies in Adenoid Cystic Carcinoma.

OPINION STATEMENT: Adenoid cystic carcinoma (ACC) is an often-indolent type of salivary gland cancer (SGC). A subset of patients develops progression or aggressive disease warranting systemic therapy in the recurrent/metastatic (R/M) setting. We recommend genomic testing for all patients with R/M disease to aid with prognostication and eligibility for potential experimental therapies. Here, we review the currently available treatment options (cytotoxic chemotherapies and vascular endothelial growth factor receptor (VEGFR)-targeting tyrosine kinase inhibitors (TKIs)). Based on limited data, we nominate regimens which may have more favorable efficacy profiles. Among the cytotoxic chemotherapies, several regimens are acceptable when incorporating a platinum agent. Among the VEGFR-targeting TKIs, lenvatinib and axitinib are the preferred options. Larger, randomized studies prioritizing combinations with mechanistic synergism are needed. Predictive biomarkers are critical, as there is currently little evidence to guide sequencing of available options for individual patients. Immunotherapy is an available option, but has been associated with only modest benefit in ACC. We go on to review other therapies that have been studied and nominate those with promise based on early clinical data.

Detection of circulating tumor human papillomavirus DNA before diagnosis of HPV-positive head and neck cancer.

Human papillomavirus (HPV), most commonly HPV16, causes a growing subset of head and neck squamous cell carcinomas (HNSCCs), including the overwhelming majority of oropharynx squamous cell carcinomas in many developed countries. Circulating biomarkers for HPV-positive HNSCC may allow for earlier diagnosis, with potential to decrease morbidity and mortality. This case-control study evaluated whether circulating tumor HPV DNA (ctHPVDNA) is detectable in prediagnostic plasma from individuals later diagnosed with HPV-positive HNSCC. Cases were participants in a hospital-based research biobank with archived plasma collected ≥6 months before HNSCC diagnosis, and available archival tumor tissue for HPV testing. Controls were biobank participants without cancer or HPV-related diagnoses, matched 10:1 to cases by sex, race, age and year of plasma collection. HPV DNA was detected in plasma and tumor tissue using a previously validated digital droplet PCR-based assay that quantifies tumor-tissue-modified viral (TTMV) HPV DNA. Twelve HNSCC patients with median age of 68.5 years (range, 51-87 years) were included. Ten (83.3%) had HPV16 DNA-positive tumors. ctHPV16DNA was detected in prediagnostic plasma from 3 of 10 (30%) patients with HPV16-positive tumors, including 3 of 7 (43%) patients with HPV16-positive oropharynx tumors. The timing of the plasma collection was 19, 34 and 43 months before cancer diagnosis. None of the 100 matched controls had detectable ctHPV16DNA. This is the first report that ctHPV16 DNA is detectable at least several years before diagnosis of HPV16-positive HNSCC for a subset of patients. Further investigation of ctHPV16DNA as a biomarker for early diagnosis of HPV16-positive HNSCC is warranted.

Sicca syndrome associated with immune checkpoint inhibitor therapy.

Cancer immunotherapy, which seeks to stimulate a patient's own immune system to combat cancer, is quickly becoming a central pillar of cancer therapeutics and has resulted in the development of many novel anticancer therapies. One subtype of cancer immunotherapy, immune checkpoint inhibitors (ICIs), has revolutionized cancer treatment and changed the standard of care for multiple indications. However, the advent of ICIs has produced a wide variety of inflammatory side effects termed immune-related adverse events (IRAEs), including ICI-induced Sicca syndrome. This article outlines the clinical features of ICI-induced Sicca syndrome and assesses its reported incidence in clinical trials, case series, and case reports across numerous cancers and treatment modalities. Presentations of ICI-induced Sicca syndrome in patients with pre-existing SjÓ§gren's disease and with extra-glandular manifestations will also be explored. The pathophysiological mechanisms underlying IRAEs, including ICI-induced Sicca syndrome, will be evaluated through an examination of existing literature. Finally, the various treatment and management strategies as well as aims for future work will be discussed and reviewed.

Oral manifestations of immune-related adverse events in cancer patients treated with immune checkpoint inhibitors.

Immunotherapy with immune checkpoint inhibitors (ICIs) has transformed cancer treatment over the past decade, improving survival rates in numerous advanced cancers. Immune-related adverse events (irAEs) are common and can affect any organ system, with many of these toxicities being well-characterized with clear grading criteria and management approaches. There has been less emphasis on oral manifestations of irAEs. This review provides an overview of oral manifestations of irAEs, including mucosal and salivary gland toxicities, and proposes a grading system and management guidelines. irAEs are common treatment-related toxicities in patients treated with ICIs. Oral irAEs can range from asymptomatic white reticulations to life-threatening mucocutaneous reactions requiring aggressive management with corticosteroids and/or permanent discontinuation of ICIs. Oral healthcare providers should be prepared to identify and manage oral irAEs in collaboration with oncologists and other specialists.

A multi-center study on safety and efficacy of immune checkpoint inhibitors in cancer patients with kidney transplant.

Immune checkpoint inhibitors (ICIs) are widely used for various malignancies. However, their safety and efficacy in patients with a kidney transplant have not been defined. To delineate this, we conducted a multicenter retrospective study of 69 patients with a kidney transplant receiving ICIs between January 2010 and May 2020. For safety, we assessed the incidence, timing, and risk factors of acute graft rejection. For efficacy, objective response rate and overall survival were assessed in cutaneous squamous cell carcinoma and melanoma, the most common cancers in our cohort, and compared with stage-matched 23 patients with squamous cell carcinoma and 14 with melanoma with a kidney transplant not receiving ICIs. Following ICI treatment, 29 out of 69 (42%) patients developed acute rejection, 19 of whom lost their allograft, compared with an acute rejection rate of 5.4% in the non-ICI cohort. Median time from ICI initiation to rejection was 24 days. Factors associated with a lower risk of rejection were mTOR inhibitor use (odds ratio 0.26; 95% confidence interval, 0.09-0.72) and triple-agent immunosuppression (0.67, 0.48-0.92). The objective response ratio was 36.4% and 40% in the squamous cell carcinoma and melanoma subgroups, respectively. In the squamous cell carcinoma subgroup, overall survival was significantly longer in patients treated with ICIs (median overall survival 19.8 months vs. 10.6 months), whereas in the melanoma subgroup, overall survival did not differ between groups. Thus, ICIs were associated with a high risk of rejection in patients with kidney transplants but may lead to improved cancer outcomes. Prospective studies are needed to determine optimal immunosuppression strategies to improve patient outcomes.

The mutational landscape of early- and typical-onset oral tongue squamous cell carcinoma.

BACKGROUND: The incidence of oral tongue squamous cell carcinoma (OTSCC) is increasing among younger birth cohorts. The etiology of early-onset OTSCC (diagnosed before the age of 50 years) and cancer driver genes remain largely unknown. METHODS: The Sequencing Consortium of Oral Tongue Cancer was established through the pooling of somatic mutation data of oral tongue cancer specimens (n = 227 [107 early-onset cases]) from 7 studies and The Cancer Genome Atlas. Somatic mutations at microsatellite loci and Catalog of Somatic Mutations in Cancer mutation signatures were identified. Cancer driver genes were identified with the MutSigCV and WITER algorithms. Mutation comparisons between early- and typical-onset OTSCC were evaluated via linear regression with adjustments for patient-related factors. RESULTS: Two novel driver genes (ATXN1 and CDC42EP1) and 5 previously reported driver genes (TP53, CDKN2A, CASP8, NOTCH1, and FAT1) were identified. Six recurrent mutations were identified, with 4 occurring in TP53. Early-onset OTSCC had significantly fewer nonsilent mutations even after adjustments for tobacco use. No associations of microsatellite locus mutations and mutation signatures with the age of OTSCC onset were observed. CONCLUSIONS: This international, multicenter consortium is the largest study to characterize the somatic mutational landscape of OTSCC and the first to suggest differences by age of onset. This study validates multiple previously identified OTSCC driver genes and proposes 2 novel cancer driver genes. In analyses by age, early-onset OTSCC had a significantly smaller somatic mutational burden that was not explained by differences in tobacco use. LAY SUMMARY: This study identifies 7 specific areas in the human genetic code that could be responsible for promoting the development of tongue cancer. Tongue cancer in young patients (under the age of 50 years) has fewer overall changes to the genetic code in comparison with tongue cancer in older patients, but the authors do not think that this is due to differences in smoking rates between the 2 groups. The cause of increasing cases of tongue cancer in young patients remains unclear.

The diagnostic performance of CT and MRI for detecting extranodal extension in patients with head and neck squamous cell carcinoma: a systematic review and diagnostic meta-analysis.

OBJECTIVE: To review the diagnostic performance of CT and MRI for detecting extranodal extension (ENE) in head and neck squamous cell carcinoma (HNSCC) patients. METHODS: MEDLINE and EMBASE databases were searched up to October 7, 2019. Studies that evaluated the diagnostic performance of CT and/or MRI for detecting ENE in HNSCC patients were included. A 2 × 2 table was reconstructed for each study. Pooled sensitivity and specificity were calculated using the bivariate model and hierarchical summary receiver operating characteristic (HSROC) model. Subgroup analyses were performed according to HPV status and radiological features. Pooled correlation coefficient for interobserver agreement was calculated. RESULTS: Twenty-two studies including 2478 patients were included. The pooled sensitivity and specificity for detecting ENE were 73% (95% CI, 62-82%) and 83% (95% CI, 75-89%), respectively, for CT, and 60% (95% CI, 49-70%) and 96% (95% CI, 85-99%), respectively, for MRI. There was substantial heterogeneity for both CT and MRI. A threshold effect was present for MRI. On subgroup analysis, the pooled specificity of CT was significantly lower in patients with HPV+ OPSCC than in patients with HPV­ oral cavity cancer or all HNSCC (74% vs. 87%; p = 0.01). Central node necrosis showed significantly higher pooled sensitivity (81% vs. 51%; p = 0.02), while infiltration of adjacent planes showed significantly higher pooled specificity (94% vs. 65%; p = 0.03). The pooled correlation coefficient was 0.72 (95% CI, 0.60-0.81). CONCLUSION: Both CT and MRI show reasonable diagnostic performance for detecting ENE in HNSCC patients and interobserver agreement was substantial. KEY POINTS: • Pooled sensitivity and specificity were 73% and 83% for CT and 60% and 96% for MRI without significant difference. • Pooled specificity was lower for HPV+ OPSCC than for HPV­ oral cavity cancer or all HNSCC (74% vs. 87%, p = 0.01), likely due to central node necrosis. • Central node necrosis showed higher sensitivity (81% vs. 51%; p = 0.02), while infiltration of adjacent planes showed higher specificity (94% vs. 65%; p = 0.03).

The Inequitable Global Burden of Lip and Oral Cancers: Widening Disparities Across Countries.

PURPOSE: In light of continued innovation in cancer immunotherapy regimens and surgical management, no studies currently exist assessing the effect of these advances on global disparities in lip and oral cavity cancer disease burden. The purpose of this study is to characterize longitudinal trends in disease burden caused by lip and oral cavity cancers globally. MATERIALS AND METHODS: This retrospective, longitudinal cohort study extracted data on lip and oral cavity cancer disease burden from The Global Health Data Exchange for 1990-2017. The primary predictor variable was country human development index (HDI). The primary outcome variable was disease burden, measured by age-standardized disability-adjusted life years (DALYs) per 100,000 population, listed for each individual country. Additional variables assessed include country-level data on alcohol consumption and tobacco smoking. Concentration indices were also calculated. Mann-Whitney U and Kruskal-Wallis one-way analysis of variance tests with Bonferroni correction were utilized with a significance threshold of 0.008. RESULTS: A total of 185 countries met inclusion criteria. Global age-standardized DALYs increased from 44.5 ± 35.7 to 51.1 ± 41.1 from 1990 to 2017. High HDI and medium HDI countries showed a +37.6% and +22.4% median increase in DALYs, respectively, which is significantly greater than very-high HDI (+3.8%) and low HDI countries (-0.5%) (P < .001). The concentration index for lip and oral cavity cancer became increasingly negative from -0.064 to -0.077 from 1990 to 2015. In 2017, disease burden was concentrated in South Asia and Eastern Europe. CONCLUSIONS: High and medium HDI countries experienced a disproportionate growth in lip and oral cavity cancer disease burden. These findings may have resulted from increased life expectancy among these countries. Global and public health policy initiatives should focus on understanding the mechanisms driving these disparities with the goal of reducing disease burden globally.

Tipifarnib in recurrent, metastatic HRAS-mutant salivary gland cancer.

BACKGROUND: To the authors' knowledge, there are no approved therapies for recurrent, metastatic (R/M) salivary gland carcinoma (SGC), but molecularly targeted therapies warrant ongoing investigation. In the current study, the authors have reported on the efficacy of tipifarnib in patients with aggressive HRAS-mutant, R/M SGC. METHODS: The current prospective, nonrandomized, multicenter, international cohort study involved 8 centers and was conducted from May 2015 to June 2019. The median follow-up was 22 months (range, 6-55 months). Subjects with HRAS-mutant R/M SGC (any histology) and disease progression within the last 6 months were enrolled. Tipifarnib was dosed orally twice daily. The authors determined the objective response rate using Response Evaluation Criteria in Solid Tumors (version 1.1), duration of response, and molecular predictors of response. RESULTS: A total of 13 patients with R/M SGC were enrolled; all had received prior systemic therapy (1-3 regimens). One objective response was observed; an additional 7 of 12 evaluable patients (58%) had stable disease as their best response with a median duration of 9 months (range, 3-14 months). Five of 7 patients had >10% tumor regression and 6 of 7 had stable disease lasting >6 months. Q61R was the most frequent activating HRAS mutation noted (7 of 13 patients; 54%), but gene variant and allele frequency did not correlate with outcomes. The median progression-free survival was 7 months (95% confidence interval, 5.9-10.1 months), and the median overall survival was 18 months (95% confidence interval, 9.6-22.4 months) with approximately 58.6% of patients alive at 1 year. Survival was similar regardless of HRAS mutant variant or co-occurring PIK3CA alterations. No participant discontinued treatment because of toxicity. CONCLUSIONS: Tipifarnib resulted in modest clinical activity with a promising disease control rate among patients with HRAS-mutant, R/M SGC who developed disease progression within the last 6 months.

Real-world outcomes treating patients with advanced cutaneous squamous cell carcinoma with immune checkpoint inhibitors (CPI).

BACKGROUND: Immunotherapy has revolutionised the treatment of advanced cutaneous squamous cell carcinoma (cSCC). It is important to understand both safety and efficacy in a real-world and trial-ineligible cSCC population. We aimed to evaluate safety, efficacy and molecular insights among a broader cSCC population, including immunosuppressed patients, treated with immune checkpoint inhibitors (CPI). METHODS: We present a cohort of advanced cSCC patients (n = 61) treated from 2015 to 2020 evaluating the best overall response (BOR) (RECISTv1.1) to CPI therapy, immune-related adverse events (irAEs) and tumour mutational burden (TMB) to correlate with outcomes. A validated geriatric scoring index (CIRS-G) was utilised to assess comorbidities among patients ≥75. These data were compared with published clinical trial results among the broader cSCC population. RESULTS: BOR to CPI was lower among the entire cohort when compared with trial data (31.5 vs. 48%, P < 0.01), with higher rates of progression (59 vs. 16.5%, P < 0.01), regardless of immunosuppression history or age. Grade 3+ irAEs were more common among responders (P = 0.02), while pre-treatment lymphocyte count and TMB predicted response (P = 0.02). CONCLUSIONS: We demonstrate comparatively lower response rates to CPI among real-world cSCC patients not explained by older age or immunosuppression history alone. Immune-related toxicity, absolute lymphocyte count and TMB predicted CPI response.

The Benefits of Adjuvant Trastuzumab for HER-2-Positive Salivary Gland Cancers.

BACKGROUND: Although high-grade salivary gland cancers (SGCs) often express androgen receptor (AR) and/or HER-2/neu, therapeutically targeting these receptors in SGC remains investigational. We investigated the prevalence of receptor expression and the benefit of adjuvant HER-2 directed therapy in the high-risk postoperative setting and explored the clinical utility of sequentially targeting these receptors in the setting of advanced disease. MATERIALS AND METHODS: We clinically annotated 95 patients with SGC (excluding adenoid cystic carcinoma) treated at our institution from 2002 to 2019 and recorded AR, HER-2/neu status, and tumor genomic profiling results when available. Clinicopathologic information was then integrated with outcomes. RESULTS: Of 95 patients, most had high-risk histologies, with salivary duct carcinoma (SDC) as the most frequent diagnosis (43, 45%). Thirty-five (37%) experienced recurrence (51% SDC). HER-2/neu was positive (1-3+) by immunostaining in 34 of 52 (65%) evaluable cases. There was no difference in survival based on HER-2/neu or AR expression. Nine of 17 (53%) patients with HER-2+ SDC received adjuvant chemoradiation with trastuzumab. Median disease-free survival (DFS) and overall survival (OS) were longer among patients with HER-2/neu 3+ staining tumors who received adjuvant trastuzumab versus those who did not (DFS, 117 vs. 9 months; p = .02; OS, 74 vs. 43 months; p = .02), with no difference among other HER-2/neu subgroups (0-2+). Two of nine (22%) patients treated with adjuvant trastuzumab demonstrated recurrence, both with low HER-2/neu staining intensity (1+). Longer time to recurrence (hazard ratio, 0.94; p = .01) predicted improved outcomes. Both androgen deprivation and HER-2-directed therapies had clinical benefit beyond the first-line metastatic setting, with partial response observed beyond second-line use. CONCLUSION: Although prospective data are lacking, the use of adjuvant trastuzumab in high-risk patients with SGC appears beneficial, particularly among patients with tumors exhibiting HER-2/neu 3+ immunostaining. IMPLICATIONS FOR PRACTICE: Results of this study showed an improved disease-free and overall survival in patients treated with adjuvant trastuzumab for high-risk salivary gland cancers with strong HER-2/neu staining intensity. Following recurrence or metastatic spread, sequential HER-2, and androgen-directed therapies may benefit certain patients with salivary gland cancer.

Health-related quality of life trajectory of treatment-naive patients with Merkel cell carcinoma receiving avelumab.

Aim: To evaluate changes in health-related quality of life (HRQoL) in a Phase II trial (NCT02155647) of treatment-naive patients with metastatic Merkel cell carcinoma treated with avelumab (15-month follow-up). Materials & methods: Mixed-effect Models for Repeated Measures were applied to HRQoL data (FACT-M; EQ-5D-5L) to assess changes over time. Clinically derived progression-free survival was compared with HRQoL deterioration-free survival. Results: Overall, we saw relative stability in HRQoL among 116 included patients, with nonprogression associated with statistically and clinically meaningful better HRQoL compared with progressive disease. Deterioration-free survival rates (49-72% at 6 months, 40-58% at 12 months) were consistently higher/better compared with progression-free survival rates (41/31% at 6/12 months). Conclusion: These findings show unique longitudinal HRQoL data for treatment-naive metastatic Merkel cell carcinoma patients treated with avelumab. Clinical trial registration: NCT02155647 (ClinicalTrials.gov).

Oral keratosis of unknown significance shares genomic overlap with oral dysplasia.

OBJECTIVES: To identify molecular characteristics of keratosis of unknown significance and to nominate pathways of molecular progression to oral cancer. Our work could provide a rationale for monitoring and treating these lesions definitively. METHODS: Patients with oral leukoplakia were eligible for our prospective observational study. We correlated alterations in cancer-associated genes with clinical and histopathologic variables (keratosis of unknown significance vs. moderate-to-severe dysplasia) and compared these alterations to a previously molecularly characterized oral cancer population. RESULTS: Of 20 enrolled patients, 13 (65%) had evidence of keratosis of unknown significance, while seven (35%) had dysplasia. Nine patients (45%) developed oral cancer (4/13 with keratosis of unknown significance, 5/7 with dysplasia). At a median follow-up of 67 (range 22-144) months, median overall survival was significantly shorter for patients with dysplasia (hazard ratio 0.11, p = .02). KMT2C and TP53 alterations were most frequent (75% and 35%, respectively). There were molecular similarities between keratosis of unknown significance and dysplasia patients, with no significant differences in mutational frequency among genes with ≥15% rate of alteration. CONCLUSIONS: Among patients with leukoplakia, both patients with keratosis of unknown significance and patients with dysplasia developed oral cancer. Molecular alterations between these two groups were similar at this sample size.

CIC-NUTM1 fusion: A case which expands the spectrum of NUT-rearranged epithelioid malignancies.

NUT carcinoma (NC) shows very aggressive clinical behavior, occurs predominantly in the thorax and head and neck region of children and adults, and is defined by the presence of NUT (aka NUTM1) rearrangement, mostly BRD4-NUTM1 fusion resulting from t(15;19)(q13; p13.1). So-called "NUT variants" harbor alternate fusions between NUTM1 and BRD3, NSD3, ZNF532, or unknown partners. Rare cases of pediatric tumors with CIC-NUTM1 fusion were recently reported in somatic soft tissue, brain, and kidney. However, such cases have not been identified in adult patients and the presence of a fusion between CIC, characteristic of CIC-rearranged sarcoma, and NUTM1-a defining feature of NC-poses a diagnostic challenge. We herein report a case of malignant epithelioid neoplasm with myoepithelial features harboring CIC-NUTM1 fusion arising in soft tissue of the head in a 60-year-old man. Immunohistochemistry revealed strong expression of NUT, but only weak ETV4 staining and negativity for keratins, EMA, p40, CD99, and WT1. SMARCB1 expression was retained. Fluorescence in situ hybridization and targeted next-generation sequencing identified a CIC-NUTM1 fusion resulting from t(15;19)(q14;q13.2). In light of morphologic features that overlap with those of NC from typical anatomical sites we have seen previously, the tumor was best classified as falling within the NC spectrum rather than CIC-associated sarcoma. This case highlights the emerging diagnostic challenges generated by newly detected gene fusions of unknown clinical and biologic significance. Careful integration of cytogenetic, molecular, and immunohistochemical findings with morphologic appearances in the diagnostic workup of undifferentiated neoplasms is essential.

The Use of Hyperbaric Oxygen for the Prevention and Management of Osteoradionecrosis of the Jaw: A Dana-Farber/Brigham and Women's Cancer Center Multidisciplinary Guideline.

BACKGROUND: Osteoradionecrosis of the jaw (ORN) is an infrequent yet potentially devastating complication of radiation therapy to the head and neck region. Treatment options include antimicrobial therapy, local sequestrectomy, resection, and the use of hyperbaric oxygen (HBO). Published data on ORN are difficult to compare because of the lack of a universally accepted classification and staging system, and the literature on the use of HBO to either prevent or successfully manage ORN is controversial and inconclusive. Therefore, we aimed to establish a standard approach for using HBO at our institution. MATERIALS AND METHODS: A literature search was conducted of articles published in the English language between January 1980 and January 2016. Retrieved articles were evaluated by two independent reviewers. Isolated case reports, abstracts, case series, review articles, and cohort studies without a control group were excluded; summary data were extracted from the remaining studies. A panel of experts from Head and Neck Oncology and Oral Medicine from the Dana-Farber Cancer Institute and Brigham and Women's Hospital reviewed the summary data and established multidisciplinary guidelines on the use of HBO for the prevention and management of ORN. RESULTS: Seven studies were evaluated and reviewed by the multidisciplinary panel. There was no consistent evidence in support of HBO for either the prevention or management of ORN. CONCLUSION: Based on the available evidence and expert opinion, routine use of HBO for the prevention or management of ORN is not recommended and is rarely used at our institution. The Oncologist 2017;22:343-350 IMPLICATIONS FOR PRACTICE: The Division of Head and Neck Oncology of Dana-Farber/Brigham and Women's Cancer Center does not recommend the routine use of HBO for the prevention or management of ORN. Adjunctive HBO may be considered for use on a case-by-case basis in patients considered to be at exceptionally high risk who have failed conservative therapy and subsequent surgical resection.

Response and acquired resistance to everolimus in anaplastic thyroid cancer.

Everolimus, an inhibitor of the mammalian target of rapamycin (mTOR), is effective in treating tumors harboring alterations in the mTOR pathway. Mechanisms of resistance to everolimus remain undefined. Resistance developed in a patient with metastatic anaplastic thyroid carcinoma after an extraordinary 18-month response. Whole-exome sequencing of pretreatment and drug-resistant tumors revealed a nonsense mutation in TSC2, a negative regulator of mTOR, suggesting a mechanism for exquisite sensitivity to everolimus. The resistant tumor also harbored a mutation in MTOR that confers resistance to allosteric mTOR inhibition. The mutation remains sensitive to mTOR kinase inhibitors.