Tissue-resident memory and circulating T cells are early responders to pre-surgical cancer immunotherapy.

Neoadjuvant immune checkpoint blockade has shown promising clinical activity. Here, we characterized early kinetics in tumor-infiltrating and circulating immune cells in oral cancer patients treated with neoadjuvant anti-PD-1 or anti-PD-1/CTLA-4 in a clinical trial (NCT02919683). Tumor-infiltrating CD8 T cells that clonally expanded during immunotherapy expressed elevated tissue-resident memory and cytotoxicity programs, which were already active prior to therapy, supporting the capacity for rapid response. Systematic target discovery revealed that treatment-expanded tumor T cell clones in responding patients recognized several self-antigens, including the cancer-specific antigen MAGEA1. Treatment also induced a systemic immune response characterized by expansion of activated T cells enriched for tumor-infiltrating T cell clonotypes, including both pre-existing and emergent clonotypes undetectable prior to therapy. The frequency of activated blood CD8 T cells, notably pre-treatment PD-1-positive KLRG1-negative T cells, was strongly associated with intra-tumoral pathological response. These results demonstrate how neoadjuvant checkpoint blockade induces local and systemic tumor immunity.

Changes in Merkel cell oncoprotein antibodies after radiation therapy in curatively treated Merkel cell carcinoma and association with recurrence.

BACKGROUND: Serum antibodies to the Merkel oncoprotein (AMERK) are detectable in approximately 50% of patients with Merkel cell carcinoma (MCC) and can be used to monitor for recurrence. The objective of this study was to characterize AMERK levels in patients receiving curative-intent radiation therapy (RT) for MCC and identify associations between AMERK and recurrence. METHODS: This was a retrospective study of patients with MCC who had baseline AMERK measurements before they received curative-intent RT from 2010 to 2020. Event-free survival (EFS) was calculated using the Kaplan-Meier method and Cox regression. The cumulative incidence of MCC-related recurrence (CIMR) was analyzed with death as a competing risk and the Gray test. RESULTS: The authors identified 88 patients who had baseline AMERK measurements, including 52 (59%) with detectable levels. AMERK positivity was associated with younger median age (67.8 vs. 72.0 years; p = .02) and tumor site (p = 0.02), with lower rates for those who had disease in the head/neck region (17.3% vs. 44.4%). EFS (71.3% vs. 60.4%; p = .30) and CIMR (24.4% vs. 39.6%; p = .23) were more favorable in AMERK-positive patients. Two patients had recurrences in the RT field, and both were AMERK-negative at baseline. The median time to AMERK nadir after RT was 11.2 months; and, in a 6-month post-RT landmark analysis, the proportion of patients who were AMERK-positive who became negative or who had levels that decreased by ≥50% were not associated with EFS (87.1% vs. 85.0%; p = .90) or CIMR (12.9% vs. 15.0%; p = .62). CONCLUSIONS: Positive AMERK baseline levels were correlated with younger age at MCC diagnosis and nonhead and neck tumor location, possibly related to the distribution of viral etiology. A specific post-RT AMERK decline correlating with EFS could not be identified.

A multicenter real-world analysis of risk factors, therapeutics, and outcomes of patients with metastatic basal cell carcinoma.

BACKGROUND: Metastatic basal cell carcinoma (mBCC) is rare and there are limited data regarding patient and tumor risk factors, optimal treatments, and disease prognosis. OBJECTIVE: To assess patient and tumor characteristics, therapeutics, and outcomes of mBCC stratified by location of metastasis. METHODS: Retrospective cohort study of 53 patients with mBCC treated at 4 large academic centers in Boston, Massachusetts; Philadelphia, Pennsylvania; and Cleveland, Ohio between January 1, 2005 and December 31, 2021. RESULTS: A total of 53 patients with mBCC were identified across 4 centers, 22 (42%) of whom had mBCC with spread limited to lymph nodes and 31 (58%) patients with distant organ spread (with or without lymph node involvement). Overall, half (n = 11) of patients with nodal metastasis achieved complete remission of disease, compared with just 1 (3%) patient with distant metastasis. The 5-year survival for nodal and distant metastatic patients was 89.3% and 61.0%, respectively. LIMITATIONS: Small sample size due to disease rarity. CONCLUSIONS AND RELEVANCE: Patients with nodal disease are more likely to have disease remission whereas patients with distant metastasis are more likely to have persistent disease and die from their disease. However, 5-year survival rates exceed 50%, even for stage IV disease.

Xevinapant plus radiotherapy in resected, high-risk, cisplatin-ineligible LA SCCHN: the phase III XRay Vision study design.

There is a significant unmet need and lack of treatment options for patients with resected, high-risk, cisplatin-ineligible locally advanced squamous cell carcinoma of the head and neck (LA SCCHN). Xevinapant, a first-in-class, potent, oral, small-molecule IAP inhibitor, is thought to restore cancer cell sensitivity to chemotherapy and radiotherapy in clinical and preclinical studies. We describe the design of XRay Vision (NCT05386550), an international, randomized, double-blind, phase III study. Approximately 700 patients with resected, high-risk, cisplatin-ineligible LA SCCHN will be randomized 1:1 to receive 6 cycles of xevinapant or placebo, in combination with radiotherapy for the first 3 cycles. The primary end point is disease-free survival, and secondary end points include overall survival, health-related quality of life, and safety.

Squamous cell carcinoma is the most common form of head and neck cancer (SCCHN) and includes cancers of the lips, mouth, throat, tongue and voice box. It is called 'locally advanced' when the cancer has spread to nearby areas but not to other parts of the body. Few treatment options are available for people with locally advanced SCCHN who have had surgery and are unable to receive a type of chemotherapy called cisplatin. Xevinapant is being developed as a possible new type of cancer treatment. It is a liquid that is taken by mouth or given through a feeding tube. Adding xevinapant to the standard treatment ­ called radiotherapy ­ aims to make radiotherapy more effective against the cancer. Researchers have started a large, international, phase III study called XRay Vision to see if adding xevinapant to radiotherapy can help stop the cancer from coming back after surgery and help people live longer. Clinical Trial Registration: NCT05386550 (ClinicalTrials.gov).

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.

Durvalumab plus tremelimumab alone or in combination with low-dose or hypofractionated radiotherapy in metastatic non-small-cell lung cancer refractory to previous PD(L)-1 therapy: an open-label, multicentre, randomised, phase 2 trial.

BACKGROUND: Patients with non-small-cell lung cancer (NSCLC) that is resistant to PD-1 and PD-L1 (PD[L]-1)-targeted therapy have poor outcomes. Studies suggest that radiotherapy could enhance antitumour immunity. Therefore, we investigated the potential benefit of PD-L1 (durvalumab) and CTLA-4 (tremelimumab) inhibition alone or combined with radiotherapy. METHODS: This open-label, multicentre, randomised, phase 2 trial was done by the National Cancer Institute Experimental Therapeutics Clinical Trials Network at 18 US sites. Patients aged 18 years or older with metastatic NSCLC, an Eastern Cooperative Oncology Group performance status of 0 or 1, and progression during previous PD(L)-1 therapy were eligible. They were randomly assigned (1:1:1) in a web-based system by the study statistician using a permuted block scheme (block sizes of three or six) without stratification to receive either durvalumab (1500 mg intravenously every 4 weeks for a maximum of 13 cycles) plus tremelimumab (75 mg intravenously every 4 weeks for a maximum of four cycles) alone or with low-dose (0·5 Gy delivered twice per day, repeated for 2 days during each of the first four cycles of therapy) or hypofractionated radiotherapy (24 Gy total delivered over three 8-Gy fractions during the first cycle only), 1 week after initial durvalumab-tremelimumab administration. Study treatment was continued until 1 year or until progression. The primary endpoint was overall response rate (best locally assessed confirmed response of a partial or complete response) and, along with safety, was analysed in patients who received at least one dose of study therapy. The trial is registered with ClinicalTrials.gov, NCT02888743, and is now complete. FINDINGS: Between Aug 24, 2017, and March 29, 2019, 90 patients were enrolled and randomly assigned, of whom 78 (26 per group) were treated. This trial was stopped due to futility assessed in an interim analysis. At a median follow-up of 12·4 months (IQR 7·8-15·1), there were no differences in overall response rates between the durvalumab-tremelimumab alone group (three [11·5%, 90% CI 1·2-21·8] of 26 patients) and the low-dose radiotherapy group (two [7·7%, 0·0-16·3] of 26 patients; p=0·64) or the hypofractionated radiotherapy group (three [11·5%, 1·2-21·8] of 26 patients; p=0·99). The most common grade 3-4 adverse events were dyspnoea (two [8%] in the durvalumab-tremelimumab alone group; three [12%] in the low-dose radiotherapy group; and three [12%] in the hypofractionated radiotherapy group) and hyponatraemia (one [4%] in the durvalumab-tremelimumab alone group vs two [8%] in the low-dose radiotherapy group vs three [12%] in the hypofractionated radiotherapy group). Treatment-related serious adverse events occurred in one (4%) patient in the durvalumab-tremelimumab alone group (maculopapular rash), five (19%) patients in the low-dose radiotherapy group (abdominal pain, diarrhoea, dyspnoea, hypokalemia, and respiratory failure), and four (15%) patients in the hypofractionated group (adrenal insufficiency, colitis, diarrhoea, and hyponatremia). In the low-dose radiotherapy group, there was one death from respiratory failure potentially related to study therapy. INTERPRETATION: Radiotherapy did not increase responses to combined PD-L1 plus CTLA-4 inhibition in patients with NSCLC resistant to PD(L)-1 therapy. However, PD-L1 plus CTLA-4 therapy could be a treatment option for some patients. Future studies should refine predictive biomarkers in this setting. FUNDING: The US National Institutes of Health and the Dana-Farber Cancer Institute.

Adjuvant radiation following clear margin resection of high T-stage cutaneous squamous cell carcinoma halves the risk of local and locoregional recurrence: A dual-center retrospective study.

BACKGROUND: Although adjuvant radiation (ART) following clear margin surgery is recommended for select high-risk cutaneous squamous cell carcinomas, efficacy data are limited. OBJECTIVE: To evaluate the impact of ART on outcomes following clear margin surgery for high T-stage cutaneous squamous cell carcinomas. METHODS: A 20-year retrospective cohort study at 2 academic centers of high T-stage cutaneous squamous cell carcinomas (Brigham and Women's Hospital T2b or T3) with negative histologic margins post resection. Local recurrence (LR) and locoregional recurrence (LRR) were compared by whether tumors received ART or observation. RESULTS: A total of 508 tumors were included, of which 96 underwent ART (ART+). ART+ had a lower 5-year cumulative incidence of LR (ART+, 3.6% [95% CI, 1.6%-7.7%] vs ART-, 8.7% [95% CI, 6.3%-12.0%]) and LRR (ART+, 7.5% [95% CI, 4.4%-11.9%] vs ART-, 15.3% [95% CI, 11.9%-22.1%]). Recurrent tumors ≥6 cm or Brigham and Women's Hospital T3 tumors were classified as high-risk due to a higher 5-year cumulative incidence of LRR (High-risk, 26.3% [95% CI, 19.0%-35.7%]). High-risk tumors treated with ART had a lower 5-year cumulative incidence of LRR (ART+, 17.2% [95% CI, 11.9%-26.4%] vs ART-, 31.0% [95% CI, 26.1%-40.8%]). LIMITATIONS: Retrospective design, heterogeneous population, variations in radiation protocols. CONCLUSION: ART following clear margin surgery for high T-stage cutaneous squamous cell carcinomas resulted in half the risk of LR and LRR.

Xevinapant or placebo plus chemoradiotherapy in locally advanced squamous cell carcinoma of the head and neck: TrilynX phase III study design.

Xevinapant is a first-in-class antagonist of inhibitor of apoptosis proteins, which enhances cancer cell sensitivity to chemotherapy and radiotherapy. In a phase II randomized study in patients with unresected locally advanced squamous cell carcinoma of the head and neck (LA SCCHN), xevinapant plus standard-of-care cisplatin-based chemoradiotherapy (CRT) showed superior efficacy versus placebo plus CRT. Here, we describe the design of TrilynX (NCT04459715), a randomized, double-blind, phase III study. In total, 700 patients with unresected LA SCCHN will be randomized 1:1 to receive xevinapant or placebo plus standard-of-care CRT followed by xevinapant monotherapy or placebo. The primary end point is event-free survival by blinded independent review committee. Secondary end points include progression-free survival, locoregional control, overall survival and safety.

Xevinapant is being developed as a new type of cancer treatment. Xevinapant works by enhancing the effects of chemotherapy and radiotherapy (chemoradiotherapy), which are standard anticancer treatments. Researchers are studying whether adding xevinapant to these treatments could be helpful for people with head and neck cancers that have not spread to other parts of the body and cannot be removed by surgery. In a study of 96 people with this disease, those treated with chemoradiotherapy plus xevinapant on average lived longer than people treated with chemoradiotherapy plus placebo (liquid that looked the same but did not contain any medicine). To confirm the results, researchers have started a larger study, called TrilynX, that will compare the same treatments in around 700 people worldwide. This study will show if adding xevinapant to chemoradiotherapy can help to keep the cancer from progressing, control symptoms better and help people live longer. Clinical trial registration: NCT04459715 (ClinicalTrials.gov).

Unusual presentation of HPV-positive squamous cell carcinoma of the nasolacrimal duct as carcinoma of unknown primary.

Most human papillomavirus (HPV)-positive carcinomas of unknown primary (CUP) in the cervical lymph nodes are ultimately found to arise from the oropharynx, which has by far the highest prevalence of HPV-positivity among head and neck tumors. However, HPV is also detected in a subset of tumors from other sites. In this case report, we describe the first reported instance of a lacrimal sac carcinoma presenting as an HPV-positive CUP. A 64-year-old male presented with isolated right-sided neck swelling, found on core biopsy to be HPV-positive squamous cell carcinoma (SCC). Initial diagnostic workup did not reveal a primary site, and he was treated for T0N1M0 oropharyngeal SCC with chemoradiation. Shortly afterwards he developed epiphora and was found to have an FDG-avid lesion along his inferior right orbit. Biopsy revealed HPV-positive SCC, presumed to be the true primary site of his previously diagnosed CUP. He was treated with surgical resection, proton-beam radiation, and carboplatin-paclitaxel. He had an excellent outcome with no evidence of disease 18 months following treatment completion. This case underscores the importance of continued vigilance and thorough investigation for a primary tumor site even when cervical nodal metastases are HPV-positive. While the vast majority of HPV-positive head and neck tumors arise in the oropharynx, other anatomical sites may also harbor HPV-positive malignancies.

Image quality comparisons of coil setups in 3T MRI for brain and head and neck radiotherapy simulations.

PURPOSE: MRI is increasingly used for brain and head and neck radiotherapy treatment planning due to its superior soft tissue contrast. Flexible array coils can be arranged to encompass treatment immobilization devices, which do not fit in diagnostic head/neck coils. Selecting a flexible coil arrangement to replace a diagnostic coil should rely on image quality characteristics and patient comfort. We compared image quality obtained with a custom UltraFlexLarge18 (UFL18) coil setup against a commercial FlexLarge4 (FL4) coil arrangement, relative to a diagnostic Head/Neck20 (HN20) coil at 3T. METHODS: The large American College of Radiology (ACR) MRI phantom was scanned monthly in the UFL18, FL4, and HN20 coil setup over 2 years, using the ACR series and three clinical sequences. High-contrast spatial resolution (HCSR), image intensity uniformity (IIU), percent-signal ghosting (PSG), low-contrast object detectability (LCOD), signal-to-noise ratio (SNR), and geometric accuracy were calculated according to ACR recommendations for each series and coil arrangement. Five healthy volunteers were scanned with the clinical sequences in all three coil setups. SNR, contrast-to-noise ratio (CNR) and artifact size were extracted from regions-of-interest along the head for each sequence and coil setup. For both experiments, ratios of image quality parameters obtained with UFL18 or FL4 over those from HN20 were formed for each coil setup, grouping the ACR and clinical sequences. RESULTS: Wilcoxon rank-sum tests revealed significantly higher (p < 0.001) LCOD, IIU and SNR, and lower PSG ratios with UFL18 than FL4 on the phantom for the clinical sequences, with opposite PSG and SNR trends for the ACR series. Similar statistical tests on volunteer data corroborated that SNR ratios with UFL18 (0.58 ± 0.19) were significantly higher (p < 0.001) than with FL4 (0.51 ± 0.18) relative to HN20. CONCLUSIONS: The custom UFL18 coil setup was selected for clinical application in MR simulations due to the superior image quality demonstrated on a phantom and volunteers for clinical sequences and increased volunteer comfort.

Short-term mortality risks among patients with oropharynx cancer by human papillomavirus status.

BACKGROUND: There is substantial variation in head and neck cancer (HNC) mortality and competing mortality among patients with HNC. In this study, the authors characterize the causes and risks of short-term mortality among patients with oropharynx cancer (OPC) and how these risks differ by human papillomavirus (HPV) status. METHODS: A custom Surveillance, Epidemiology, and End Results (SEER) data set with HPV status was used to identify 4930 patients with OPC who were diagnosed with nonmetastatic (M0) disease from 2013 to 2014, including 3560 (72.2%) HPV-positive patients and 1370 HPV-negative patients. Causes of death and cumulative incidence estimates for HNC-specific mortality, competing mortality, second-cancer mortality, and noncancer mortality were analyzed by HPV status. Risk factors for mortality events were determined using multivariable competing risk regression models. RESULTS: Compared with HPV-negative patients, HPV-positive patients had a lower risk of 2-year cumulative incidence of all-cause mortality (10.4% vs 33.3%; P < .0001) and a lower risk of both HNC-specific mortality (4.8% vs 16.2%; P < .0001) and competing-cause mortality (5.6% vs 16.8%; P < .0001). Second-cancer mortality was the most common cause of non-HNC mortality among HPV-negative patients. Both second-cancer mortality and noncancer mortality were significantly higher among patients who had HPV-negative OPC (10.8% and 6.1%, respectively) compared with those who had HPV-positive OPC (2.4% and 3.2%, respectively; both P < .0001). The median follow-up was 11 months (range 1-23 months) in this cohort with known HPV-status. CONCLUSIONS: Patients with HPV-positive and HPV-negative OPC have significantly different rates of both HNC mortality and competing mortality. HPV-negative patients are at substantial risk of competing mortality, even within 2 years of cancer diagnosis. These differences can inform power calculations for clinical trials and patient management in the acute and survivorship settings.

Response rate and local recurrence after concurrent immune checkpoint therapy and radiotherapy for non-small cell lung cancer and melanoma brain metastases.

BACKGROUND: Prior literature has suggested synergy between immune checkpoint therapy (ICT) and radiotherapy (RT) for the treatment of brain metastases (BrM), but to the authors' knowledge the optimal timing of therapy to maximize this synergy is unclear. METHODS: A total of 199 patients with melanoma and non-small cell lung cancer with BrM received ICT and RT between 2007 and 2016 at the study institution. To reduce selection biases, individual metastases were included only if they were treated with RT within 90 days of ICT. Concurrent treatment was defined as RT delivered on the same day as or in between doses of an ICT course; all other treatment was considered to be nonconcurrent. Multivariable Cox proportional hazards models were used to assess time to response and local disease recurrence on a per-metastasis basis, using a sandwich estimator to account for intrapatient correlation. RESULTS: The final cohort included 110 patients with 340 BrM, with 102 BrM treated concurrently and 238 BrM treated nonconcurrently. Response rates were higher with the use of concurrent treatment (70% vs 47%; P < .001), with correspondingly lower rates of progressive disease (5% vs 26%; P < .001). On multivariable analysis, concurrent treatment was found to be associated with improved time to response (hazard ratio, 1.76; 95% CI, 1.18-2.63 [P = .006]) and decreased local recurrence (hazard ratio, 0.42; 95% CI, 0.23-0.78 [P = .006]). This effect appeared to be greater for melanoma than for non-small cell lung cancer, although interaction tests were not statistically significant. Only 1 of 103 metastases which had a complete response later developed disease progression. CONCLUSIONS: Concurrent RT and ICT may improve response rates and decrease local recurrence of brain metastases compared with treatment that was nonconcurrent but delivered within 90 days. Further study of this combination in prospective, randomized trials is warranted.

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.

Denaturation-Enhanced Droplet Digital PCR for Liquid Biopsies.

BACKGROUND: Although interest in droplet-digital PCR technology (ddPCR) for cell-free circulating DNA (cfDNA) analysis is burgeoning, the technology is compromised by subsampling errors and the few clinical targets that can be analyzed from limited input DNA. The paucity of starting material acts as a "glass ceiling" in liquid biopsies because, irrespective how analytically sensitive ddPCR techniques are, detection limits cannot be improved past DNA input limitations. METHODS: We applied denaturation-enhanced ddPCR (dddPCR) using fragmented genomic DNA (gDNA) with defined mutations. We then tested dddPCR on cfDNA from volunteers and patients with cancer for commonly-used mutations. gDNA and cfDNA were tested with and without end repair before denaturation and digital PCR. RESULTS: By applying complete denaturation of double-stranded DNA before ddPCR droplet formation the number of positive droplets increased. dddPCR using gDNA resulted in a 1.9-2.0-fold increase in data-positive droplets, whereas dddPCR applied on highly-fragmented cfDNA resulted in a 1.6-1.7-fold increase. End repair of cfDNA before denaturation enabled cfDNA to display a 1.9-2.0-fold increase in data-positive signals, similar to gDNA. Doubling of data-positive droplets doubled the number of potential ddPCR assays that could be conducted from a given DNA input and improved ddPCR precision for cfDNA mutation detection. CONCLUSIONS: dddPCR is a simple and useful modification in ddPCR that enables extraction of more information from low-input clinical samples with minor change in protocols. It should be applicable to all ddPCR platforms for mutation detection and, potentially, for gene copy-number analysis in cancer and prenatal screening.

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.

Definitive chemoradiation alters the immunologic landscape and immune checkpoints in head and neck cancer.

BACKGROUND: Preclinical and clinical studies suggest potential synergy between high dose per fraction focal radiation and immunotherapy. However, conventionally fractionated radiation regimens in combination with concurrent chemotherapy are more commonly administered to patients as definitive treatment and may have both immune-stimulating and -suppressive effects. METHODS: We prospectively collected longitudinal samples from head and neck squamous cell carcinoma patients receiving definitive radiation therapy. We quantified changes in populations of circulating immune cells and chemokines CXCL9, 10, and 16. Analyses of humoral and cellular immune responses were conducted in select patients via proteomic analysis and T-cell receptor sequencing. RESULTS: Treatment not only increased circulating CD-8+ T-effector cells, but also myeloid-derived suppressor cells, regulatory T cells, and checkpoint receptor-expressing T cells, particularly PD-1+ T cells. Significant decreases in CXCL10 and increases in CXLC16 were noted. Treatment also increased the percentage of unique and dominant TCR clones, and increased humoral responses as measured by proteomic array. CONCLUSIONS: Our results suggest that fractionated chemoradiation leads to quantifiable effects in circulating immune mediators, including a balance of stimulatory and suppressive mechanisms. These results suggest future combinations with immune checkpoint blockade.