Clinical acceptability of automatically generated lymph node levels and structures of deglutition and mastication for head and neck radiation therapy

Background and Purpose

Auto-contouring of complex anatomy in computed tomography (CT) scans is a highly anticipated solution to many problems in radiotherapy. In this study, artificial intelligence (AI)-based auto-contouring models were clinically validated for lymph node levels and structures of swallowing and chewing in the head and neck.

Materials and Methods

CT scans of 145 head and neck radiotherapy patients were retrospectively curated. One cohort (n = 47) was used to analyze seven lymph node levels and the other (n = 98) used to analyze 17 swallowing and chewing structures. Separate nnUnet models were trained and validated using the separate cohorts. For the lymph node levels, preference and clinical acceptability of AI vs human contours were scored. For the swallowing and chewing structures, clinical acceptability was scored. Quantitative analyses of the test sets were performed for AI vs human contours for all structures using overlap and distance metrics.

Results

Median Dice Similarity Coefficient ranged from 0.77 to 0.89 for lymph node levels and 0.86 to 0.96 for chewing and swallowing structures. The AI contours were superior to or equally preferred to the manual contours at rates ranging from 75% to 91%; there was not a significant difference in clinical acceptability for nodal levels I-V for manual versus AI contours. Across all AI-generated lymph node level contours, 92% were rated as usable with stylistic to no edits. Of the 340 contours in the chewing and swallowing cohort, 4% required minor edits.

Conclusions

An accurate approach was developed to auto-contour lymph node levels and chewing and swallowing structures on CT images for patients with intact nodal anatomy. Only a small portion of test set auto-contours required minor edits.

Analysis of B7-H4 Expression Across Salivary Gland Carcinomas Reveals Adenoid Cystic Carcinoma-Specific Prognostic Relevance

B7-H4 (VTCN1), a member of the B7 family, is overexpressed in several types of cancer. Here we investigated the pattern of expression of B7-H4 in salivary gland carcinomas (SGC) and assessed its potential as a prognostic marker and therapeutic target. Immunohistochemistry (IHC) analyses were performed in a cohort of 340 patient tumors, composed of 124 adenoid cystic carcinomas (ACC), 107 salivary duct carcinomas (SDC), 64 acinic cell carcinomas, 36 mucoepidermoid carcinomas (MEC), 9 secretory carcinomas (SC), as well as 20 normal salivary glands (controls). B7-H4 expression was scored and categorized into negative (<5% expression of any intensity), low (5%-70% expression of any intensity or >70% with weak intensity), or high (>70% moderate or strong diffuse intensity). The associations between B7-H4 expression and clinicopathologic characteristics, as well as overall survival, were assessed. Among all tumors, B7-H4 expression was more prevalent in ACC (94%) compared with those of SC (67%), MEC (44%), SDC (32%), and acinic cell carcinomas (0%). Normal salivary gland tissue did not express B7-H4. High expression of B7-H4 was found exclusively in ACC (27%), SDC (11%), and MEC (8%). In SDC, B7-H4 expression was associated with female gender (P = .002) and lack of androgen receptor expression (P = .012). In ACC, B7-H4 expression was significantly associated with solid histology (P < .0001) and minor salivary gland primary (P = .02). High B7-H4 expression was associated with a poorer prognosis in ACC, regardless of clinical stage and histologic subtype. B7-H4 expression was not prognostic in the non-ACC SGC evaluated. Our comparative study revealed distinct patterns of B7-H4 expression according to SGC histology, which has potential therapeutic implications. B7-H4 expression was particularly high in solid ACC and was an independent prognostic marker in this disease but not in the other SGC assessed.

Stereotactic Boost and Short-Course Radiotherapy for p16-Associated Oropharynx Cancer (SHORT-OPC): First Planned Interim Safety Analysis from a Randomized Phase II Trial

PURPOSE/OBJECTIVE(S)

There is a need for safe treatment de-intensification in p16+ oropharynx cancer (OPC). The standard of care (SOC) radiotherapy (RT) regimen is cumbersome and associated with high toxicity. Stereotactic radiotherapy (SBRT) and multimodality image guidance is an opportunity to precisely target the gross tumor while safely reducing elective irradiation dose. We aim to assess the safety and efficacy of a short course RT for p16+ OPC, consisting of an SBRT boost to the gross tumor volume (GTV) followed by de-escalated elective irradiation.

MATERIALS/METHODS

In this randomized phase II trial, patients with p16-positive, stage I-II OPSCC with primary tumor <30 cc (8th Ed AJCC) are planned with combined CT, MRI and FDG-PET, and randomized to 1) SBRT boost (14 Gy in 2 fractions) to the GTV followed with de-escalated RT (+/- Cisplatin) to a dose of 40 Gy in 20 fractions, or 2) SOC RT (+/- Cisplatin) to a dose of 70 Gy in 33 fractions to the GTV and 59.4-54Gy (or equivalent) to the intermediate-to-low dose elective region. Patients are stratified by stage (I vs. II) and use of chemotherapy. The primary endpoint of the trial is locoregional control at 2 years, powered for a sample size of 100 patients. A Bayesian adaptive design includes 2 planned safety interim analysis using grade ≥ 3 subacute toxicities >40% as a stopping criterion, and 1 planned futility analysis. Acute adverse events (AE) are defined as those occurring ≤ 60 days from RT, subacute AE between 60-180 days after RT, and late AE >180 days from RT. This is the first planned toxicity analysis.

RESULTS

Twenty-one patients were randomly assigned and eligible (11 in SOC and 10 in experimental arm). Median age was 69 years (range 49-84); 29% and 71% had stage T1 and T2, while 10%, 85% and 1 patient had N0, N1 and N2 disease, respectively. RT alone and chemoradiation was administered in 67% and 33% of patients, respectively. At a median follow-up of 11 months (range 1.7-17.6), there was 1 local recurrence at the primary tumor site in the SOC arm (at 10 month) and no recurrence in the experimental arm. All enrolled patients remain alive at the time of analysis. There was a 54.5% rate of grade 3 acute AE in the SOC arm and 30.0% rate of grade 3 acute AE in the experimental arm. More specifically, 1, 5 (45%), 2 (18%), and 2 (18%) versus 0, 1, 1 and 1 patient developed acute grade 3 dysphagia, mucositis, pain and dermatitis in the SOC and experimental arm, respectively. There was no acute grade 4 or 5 toxicity. There was no grade ≥ 3 subacute toxicity or late toxicity in both arms.

CONCLUSION

This primary safety analysis showed that SBRT boost followed by a short course of de-escalated elective irradiation in p16+ OPC has limited early toxicity and meets criteria for study continuation.

Clinical Acceptability of Automatically Generated Elective Lymph Node Volumes for Head and Neck Cancer Patients

PURPOSE/OBJECTIVE(S)

Manual contouring of head and neck lymph node levels is a time-intensive process prone to provider-specific variation. The purpose of this work is to generate a clinical segmentation tool while minimizing the amount of manual effort required by physicians to develop training datasets and review contours. Here we investigate an approach to curate, develop, and clinically validate an auto-contouring model for standard cervical lymph node volumes in the head and neck using a publicly available deep learning architecture. This model updates our previously validated tool to reflect modern practices in lymph node segmentation.

MATERIALS/METHODS

With the assistance of a resident physician, five radiation oncologists manually contoured individual lymph node levels on CT scans for three separate patients treated definitively with radiation or chemoradiation for oropharynx cancer, resulting in 15 unique ground truth cases. These cases were then used to train an nnUnet deep-learning model to generate automated contours for 32 additional cases. These 32 cases were reviewed, manually edited, and used to create the final model. Finally, the model was used to generate contours on the original 15 CT scans (testing cohort), and providers compared these automated contours with the ground-truth (manual) contours. Two blinded studies were performed. In a double-blinded fashion, providers were first asked to select which set of contours they would prefer to use in clinical practice as a starting point for actual cases. Second, they scored each contour on a Likert scale (1-5) to indicate clinical acceptability, ranging from completely unusable to usable without modification.

RESULTS

Across all lymph node levels (IA, IB, II, III, IV, V, RP), average Dice Similarity Coefficient ranged from 0.77 to 0.89 for AI vs manual contours in the testing cohort. These AI and manual lymph node contours were reviewed by 5 physicians each, resulting in 525 preference scores. Across all lymph nodes, the AI contour was superior to or equally preferred to the manual contours at rates ranging from 75% to 91% in the first blinded study. In the second blinded study, physician preference for the manual vs AI contour was statistically different for only the RP contours (p < 0.01). Thus, there was not a significant difference in clinical acceptability for nodal levels I-V for manual versus AI contours. Across all physician-generated contours, 82% were rated as usable with stylistic to no edits, and across all AI-generated contours, 92% were rated as usable with stylistic to no edits.

CONCLUSION

An approach to generate clinically acceptable automated contours for cervical lymph node levels in the head and neck was demonstrated. Furthermore, for nodal levels I-V, there was no significant difference in clinical acceptability in manual vs AI contours. Because we were able to generate and validate a model for each lymph node level individually, the output is applicable to a complete range of disease in which cervical lymph nodes are treated.

Radiation Therapy Sensitizes Head-and-Neck Cancer Cells to Killing by Chimeric Antigen Receptor (CAR)-NK Cells Targeting CD70

PURPOSE/OBJECTIVE(S)

CAR-T cell therapy is limited by toxicity, high cost, logistical manufacturing issues in the autologous setting and risk of GVHD in the allogeneic setting. Substitution of T cells with NK cells opens the possibility for an allogeneic off-the-shelf product with a better safety profile. However, the inadequate efficacy of CAR-NK cells against solid tumors can be extrapolated from experience with CAR-T cells. There is limited but promising preclinical evidence that radiation therapy (RT) enhances CAR-T cell tumoricidal activity against solid tumors. However, there is no data examining the potential synergy between RT and CAR-NK cell therapy.

MATERIALS/METHODS

We engineered CAR-NK cells with CD27 receptor as extracellular domain to target its natural ligand CD70, which is overexpressed in head-and-neck cancers (HNSCC). CAR-NK cell killing was assessed real-time through xCELLigence cytotoxicity assays. CD70+ OQ01 human HNSCCs were used for most experiments. FaDu is a CD70- HNSCC (negative ctrl). UMRC3 is a CD70+ kidney cancer cell line (positive ctrl). CD70 expression pre- and post-RT was assessed by flow cytometry and Western blot. Ionizing RT was compared at 5 doses: 0, 1.75, 3.5, 7, and 14 Gy. A single dose of 3.5 Gy was used for most experiments. Post-radiation effects were generally assessed at 3 days or 9 days post-RT. Intracellular staining was used to assess NK cell expression of IFN-γ, CD107a, and TNF-α by flow cytometry. CD27/CD70 interaction blockade was through α-CD27 pre-treatment of CAR-NK cells.

RESULTS

OQ01 HNSCCs heterogeneously express CD70 and are killed by CD70 CAR-NK cells in vitro. Pre-conditioning low-dose RT of 3.5 Gy applied to OQ01 HNSCCs 3 days prior to coculture with NK cells enhances CD70 CAR-NK cell killing, with ∼30% increased cytotoxicity against the tumor cells. Low-dose RT by itself did not induce acute cytolysis. As a possible mechanism for the increased sensitivity of irradiated OQ01 cells to CD70 CAR-NK cells, we found that RT enhances CD70 expression among HNSCCs in a dose-dependent manner. There was no increase in NK cell expression of IFN-γ, CD107a, and TNF-α with exposure to irradiated target cells. CD27/CD70 blockade does not solely abrogate RT-induced sensitization toward CAR-NK cell killing. Despite RT induction of transient increased expression of CD70, which normalizes by 9 days post-RT, there is persistent increase in RT-synergized target cell killing even at this later timepoint. Thus, altogether, RT sensitizes CD70-expressing HNSCC cells to CAR-NK cell killing in vitro.

CONCLUSION

This work represents the first preclinical study to identify the synergy of RT and CAR-NK cell therapy in solid tumors and is the first demonstration of CAR-NK cell activity against human HNSCCs. We show significantly enhanced potency of CAR-NK cells against irradiated tumor cells in vitro. Collectively, this research will be vital to guide efforts expanding into other target antigens and tumor types.

Irradiated Extramedullary Acute Myeloid Leukemia Increases Survival in a Leukemic Mouse Model

PURPOSE/OBJECTIVE(S)

The systemic nature of AML likely limits their immunogenicity because antigen presentation is primarily mediated by splenic dendritic cells, which induces immune tolerance. Since antigen presentation in tissue draining lymph nodes can induce anti-tumor immune responses, we hypothesized that local irradiation of cutaneous, extramedullary leukemias will increase immunogenic cell death, dendritic cell maturation and improved survival.

MATERIALS/METHODS

A murine AML cell line C1498 was assessed for immunogenic markers calreticulin (CALR), HMGB1 and cGAS-STING pathway using fluorescence cytometry and qRT-PCR. Syngeneic mice were injected with C1498 subcutaneously to model extramedullary lesions and intravenously to model systemic leukemias. Cells and subcutaneous tumor were focally irradiated with 2 Gy or 8 Gy. Two-way ANOVA and Student's t-test were used for paired-wise comparisons. Survival was estimated by Kaplan-Meier plot and groups were compared using log-rank test.

RESULTS

C1498 cells or tumors irradiated with 2 Gy or 8 Gy showed increased CALR and HMGB1 as well as (cGAS/Md21b1; 5-fold; p<0.001) and interferon alpha (Ifna; 3-fold; p<0.001) after 48h (18- and 4-fold, respectively; p<0.05) compared to not treated controls (NTC). Irradiated C1498 subcutaneous tumors displayed increased CD11b-positive cells (9-fold; p<0.001), CD11c (6-fold; p<0.001), and MHCII-positive CD11c cells (4-fold; p<0.01) in irradiated tumors compared to NTC. Irradiation of subcutaneous C1498 tumors increased median survival in mice also injected with C1498 cells intravenously compared to non-irradiated mice bearing systemic leukemias (46 vs. 25 days; p<0.01). Irradiation of C1498 tumors combined with anti-PDL1 treatment further increased median survival in our leukemia model compared to untreated controls (>50 vs. <30 days; p<0.001).

CONCLUSION

Irradiated extramedullary AML increased immunogenic markers and activation of immune effector cells that correlated with increased survival in mice also bearing systemic leukemia. These results suggest focal irradiation of extramedullary AML may facilitate eradiation of systemic leukemias.

Fractionated Stereotactic Radiotherapy in the Management of Dural Recurrence of Olfactory Neuroblastoma

PURPOSE/OBJECTIVE(S)

Treatment protocols for dural recurrence among esthesioneuroblastoma patients have not been standardized. We assess the outcomes of fractionated stereotactic radiotherapy (FSR) for patients with olfactory neuroblastoma (ONB) dura-based recurrences.

MATERIALS/METHODS

We identified ONB patients with dura-based recurrences treated with FSR after prior radiotherapy who were enrolled between 2013 and 2022 in our prospective head and neck reirradiation and skull base registries. In-field tumor control (within 2 cm of prescribed radiotherapy volume) and out-of-field tumor control (non-contiguous or contralateral dura, nodal, or distant metastases) were analyzed.

RESULTS

Thirteen patients with 28 dural lesions were included in this analysis. All patients were initially treated with surgery to their primary paranasal sinus disease; 69% with a craniofacial approach followed by adjuvant radiotherapy to a median dose of 63 Gy (range 60-72.4 Gy) prescribed to the resected tumor bed. Patients re-presented with dural recurrence at median 58.3 months (range 35.0 - 163.0 months) from completion of their initial treatment. Two patients underwent dural resections. On presentation of recurrence, 4 patients had 1 lesion treated, with a median of 2 lesions treated (range 1-4 lesions). All dural based tumors were treated with FSR to a median dose of 27 Gy in 3 fractions delivered QOD. 68Ga-DOTATATE PET/CT was utilized for FSR treatment planning in 31% of cases. The median follow up from FSR was 23.3 months (range: 13.1 - 51.6 months). The 1-year overall survival and progression free survival was 75% and 38%, respectively. The 1- and 2-year in-field control rate was 85% and 75%, respectively. Among treated lesions, 25 of 28 (89%) responded or remained stable following FSR. Two patients (3 lesions) had evidence of in-field radiographic progression at 17 and 9 months, respectively. Five patients (38%) experienced progression in the contralateral or non-contiguous dura, and 5 patients (38%) developed distant metastases. The overall out-of-field progression rate was 58% at 1 year. There was no grade 3 or higher toxicity observed. Three patients (23%) developed asymptomatic changes on MRI consistent with brain necrosis, all of which occurred in a previously irradiated region.

CONCLUSION

In the largest single institution study of FSR reirradiation for ONB dural recurrence to date, high local control rates with minimal toxicity are attainable. However, subsequent out-of-field dural recurrences and/or distant metastases remain problematic.

Prevalence of pituitary hormone dysfunction following radiotherapy for sinonasal and nasopharyngeal malignancies

BACKGROUND

There are limited studies and no surveillance protocols on pituitary dysfunction for adults who underwent anterior skull base radiation.

METHODS

Cross-sectional study of 50 consecutive patients with sinonasal or nasopharyngeal cancer who underwent definitive radiotherapy. The mean radiation doses, prevalence of pituitary dysfunction, and associated factors were calculated.

RESULTS

Pituitary hormone levels were abnormal in 23 (46%) patients, including 6 (12%) with symptomatic abnormalities requiring treatment. The most common hormonal abnormality was hyperprolactinemia (30%), central hypothyroidism (8%) and central hypogonadism (6%). Patients with abnormal pituitary hormone values received higher mean radiation doses to the pituitary gland (1143 cGy, P = 0.04), pituitary stalk (1129 cGy, P = 0.02), optic chiasm (1094 cGy, P = 0.01), and hypothalamus (900 cGy, P = 0.01).

CONCLUSIONS

Nearly half of the patients had abnormal pituitary function, including over a tenth requiring treatment. There may be a dose-dependent association between hormonal dysfunction and radiation.

Temporal characterization of acute pain and toxicity kinetics during radiation therapy for head and neck cancer. A retrospective study

Objectives

Pain during Radiation Therapy (RT) for oral cavity/oropharyngeal cancer (OC/OPC) is a clinical challenge due to its multifactorial etiology and variable management. The objective of this study was to define complex pain profiles through temporal characterization of pain descriptors, physiologic state, and RT-induced toxicities for pain trajectories understanding.

Materials and methods

Using an electronic health record registry, 351 OC/OPC patients treated with RT from 2013 to 2021 were included. Weekly numeric scale pain scores, pain descriptors, vital signs, physician-reported toxicities, and analgesics were analyzed using linear mixed effect models and Spearman's correlation. Area under the pain curve (AUCpain) was calculated to measure pain burden over time.

Results

Median pain scores increased from 0 during the weekly visit (WSV)-1 to 5 during WSV-7. By WSV-7, 60% and 74% of patients reported mouth and throat pain, respectively, with a median pain score of 5. Soreness and burning pain peaked during WSV-6/7 (51%). Median AUCpain was 16% (IQR (9.3-23)), and AUCpain significantly varied based on gender, tumor site, surgery, drug use history, and pre-RT pain. A temporal increase in mucositis and dermatitis, declining mean bodyweight (-7.1%; P < 0.001) and mean arterial pressure (MAP) 6.8 mmHg; P < 0.001 were detected. Pulse rate was positively associated while weight and MAP were negatively associated with pain over time (P < 0.001).

Conclusion

This study provides insight on in-depth characterization and associations between dynamic pain, physiologic, and toxicity kinetics. Our findings support further needs of optimized pain control through temporal data-driven clinical decision support systems for acute pain management.

Surgery After BRAF-Directed Therapy Is Associated with Improved Survival in BRAFV600E Mutant Anaplastic Thyroid Cancer: A Single-Center Retrospective Cohort Study

Background: The aim of this study was to describe the oncologic outcomes of patients with BRAF^V600E-mutated anaplastic thyroid cancer (ATC) who had neoadjuvant BRAF-directed therapy with subsequent surgery. For context, we also reviewed patients who received BRAF-directed therapy after surgery, and those who did not have surgery after BRAF-directed therapy. Methods: This was a single-center retrospective cohort study conducted at a tertiary care cancer center in Texas from 2017 to 2021. Fifty-seven consecutive patients with BRAF^V600E-mutated ATC and at least 1 month of BRAF-directed therapy were included. Primary outcomes were overall survival (OS) and progression-free survival (PFS). Results: All patients had stage IVB (35%) or IVC (65%) ATC. Approximately 70% of patients treated with BRAF-directed therapy ultimately had surgical resection of residual disease. Patients who had neoadjuvant BRAF-directed therapy followed by surgery (n = 32) had 12-month OS of 93.6% [confidence interval (CI) 84.9-100] and PFS of 84.4% [CI 71.8-96.7]. Patients who had surgery before BRAF-directed therapy (n = 12) had 12-month OS of 74.1% [CI 48.7-99.5] and PFS of 50% [CI 21.7-78.3]. Finally, patients who did not receive surgery after BRAF-directed therapy (n = 13) had 12-month OS of 38.5% [CI 12.1-64.9] and PFS of 15.4% [CI 0-35.0]. Neoadjuvant BRAF-directed therapy reduced tumor size, extent of surgery, and surgical morbidity score. Subgroup analysis suggested that any residual ATC in the surgical specimen was associated with significantly worse 12-month OS and PFS (OS = 83.3% [CI 62.6-100], PFS = 61.5% [CI 35.1-88]) compared with patients with pathologic ATC complete response (OS = 100%, PFS = 100%). Conclusions: We observed that neoadjuvant BRAF-directed therapy reduced extent of surgery and surgical morbidity. While acknowledging potential selection bias, the 12-month OS rate appeared higher in patients who had BRAF-directed therapy followed by surgery as compared with BRAF-directed therapy without surgery; yet, it was not significantly different from surgery followed by BRAF-directed therapy. PFS appeared higher in patients treated with neoadjuvant BRAF-directed therapy relative to patients in the other groups. These promising results of neoadjuvant BRAF-directed therapy followed by surgery for BRAF-mutated ATC should be confirmed in prospective clinical trials.

Decreased overall survival in patients with locally advanced head and neck cancer receiving definitive radiotherapy and concurrent cetuximab: National Cancer Database analysis

BACKGROUND

Recently, randomized trials have questioned the efficacy of cetuximab-based bioradiotherapy compared to chemoradiation for patients with squamous cell carcinoma of the oropharynx, larynx, and hypopharynx (HNSCC). We compared the OS of patients treated with radiotherapy alone (RTonly), chemoradiotherapy (chemoRT), and bioradiotherapy (cetuxRT).

METHODS

Patients with stage III-IVB HNSCC treated with RTonly, chemoRT, or cetuxRT were identified in the National Cancer Database. OS was estimated using Cox proportional hazards. Analyses were conducted on the overall cohort and propensity matched cohorts.

RESULTS

31 014 patients were treated with RTonly (22%), chemoRT (72%), or cetuxRT (6%) from 2013 to 2016. The 2-year OS was 69% for RTonly, 79% for chemoRT, and 66% for cetuxRT (p < 0.001). In the overall and propensity-matched cohorts, chemoRT and RTonly were associated with improved OS as compared to cetuxRT (p ≤ 0.001).

CONCLUSION

Compared to chemoRT or RTonly, cetuxRT is associated with decreased OS for patients with HNSCC, suggesting minimal benefit of bioradiotherapy in this population.

Genetic Changes Driving Immunosuppressive Microenvironments in Oral Premalignancy

Oral premalignant lesions (OPLs) are the precursors to oral cavity cancers, and have variable rates of progression to invasive disease. As an intermediate state, OPLs have acquired a subset of the genomic alterations while arising in an oral inflammatory environment. These specific genomic changes may facilitate the transition to an immune microenvironment that permits malignant transformation. Here, we will discuss mechanisms by which OPLs develop an immunosuppressive microenvironment that facilitates progression to invasive cancer. We will describe how genomic alterations and immune microenvironmental changes co-evolve and cooperate to promote OSCC progression. Finally, we will describe how these immune microenvironmental changes provide specific and unique evolutionary vulnerabilities for targeted therapies. Therefore, understanding the genomic changes that drive immunosuppressive microenvironments may eventually translate into novel biomarker and/or therapeutic approaches to limit the progression of OPLs to potential lethal oral cancers.

Proton Image-guided Radiation Assignment for Therapeutic Escalation via Selection of locally advanced head and neck cancer patients [PIRATES]: A Phase I safety and feasibility trial of MRI-guided adaptive particle radiotherapy

INTRODUCTION

Radiation dose-escalation for head and neck cancer (HNC) patients aiming to improve cure rates is challenging due to the increased risk of unacceptable treatment-induced toxicities. With "Proton Image-guided Radiation Assignment for Therapeutic Escalation via Selection of locally advanced head and neck cancer patients" (PIRATES), we present a novel treatment approach that is designed to facilitate dose-escalation while minimizing the risk of dose-limiting toxicities for locally advanced HPV-negative HNC patients. The aim of this Phase I trial is to assess the safety & feasibility of PIRATES approach.

METHODS

The PIRATES protocol employs a multi-faceted dose-escalation approach to minimize the risk of dose-limiting toxicities (DLTs): 1) sparing surrounding normal tissue from extraneous dose with intensity-modulated proton therapy, 2) mid-treatment hybrid hyper-fractionation for radiobiologic normal tissue sparing; 3) Magnetic Resonance Imaging (MRI) guided mid-treatment boost volume adaptation, and 4) iso-effective restricted organ-at-risk dosing to mucosa and bone tissues.The time-to-event Bayesian optimal interval (TITE-BOIN) design is employed to address the challenge of the long DLT window of 6 months and find the maximum tolerated dose. The primary endpoint is unacceptable radiation-induced toxicities (Grade 4, mucositis, dermatitis, or Grade 3 myelopathy, osteoradionecrosis) occurring within 6 months following radiotherapy. The second endpoint is any grade 3 toxicity occurring in 3-6 months after radiation.

DISCUSSION

The PIRATES dose-escalation approach is designed to provide a safe avenue to intensify local treatment for HNC patients for whom therapy with conventional radiation dose levels is likely to fail. PIRATES aims to minimize the radiation damage to the tissue surrounding the tumor volume with the combination of proton therapy and adaptive radiotherapy and within the high dose tumor volume with hybrid hyper-fractionation and not boosting mucosal and bone tissues. Ultimately, if successful, PIRATES has the potential to safety increase local control rates in HNC patients with high loco-regional failure risk.Trial registration: ClinicalTrials.gov ID: NCT04870840; Registration date: May 4, 2021.Netherlands Trial Register ID: NL9603; Registration date: July 15, 2021.

Stereotactic body ablative radiotherapy for reirradiation of small volume head and neck cancers is associated with prolonged survival: Large, single-institution, modern cohort study

BACKGROUND

Recurrent head and neck cancer has poor prognosis. Stereotactic body radiotherapy (SBRT) may improve outcomes by delivering ablative radiation doses.

METHODS

We reviewed patients who received definitive-intent SBRT reirradiation at our institution from 2013 to 2020. Patterns of failure, overall survival (OS), and toxicities were analyzed.

RESULTS

One hundred and thirty-seven patients were evaluated. The median OS was 44.3 months. The median SBRT dose was 45 Gy and median target volume 16.9 cc. The 1-year local, regional, and distant control was 78%, 66%, and 83%, respectively. Systemic therapy improved regional (p = 0.004) and distant control (p = 0.04) in nonmetastatic patients. Grade 3+ toxicities were more common at mucosal sites (p = 0.001) and with concurrent systemic therapy (p = 0.02).

CONCLUSIONS

In a large cohort of SBRT reirradiation for recurrent, small volume head and neck cancers, a median OS of 44.3 months was observed. Systemic therapy improved regional and distant control. Toxicities were modulated by anatomic site and systemic therapy.

Biology of the Radio- and Chemo-Responsiveness in HPV Malignancies

In multiple anatomic sites, patients with cancers associated with the Human Papillomavirus (HPV) experience better locoregional control and overall survival after radiotherapy and/or chemoradiotherapy than patients with HPV-negative cancers. These improved outcomes suggest that relatively unique biological features in HPV-positive cancers may increase sensitivity to DNA damaging agents as well as an impaired DNA damage response. This review will address potential biological mechanisms driving this increased sensitivity of HPV-positive cancer to radiation and/or chemotherapy. This review will discuss the clinical and preclinical observations that support the intrinsic radiosensitivity and/or chemosensitivity of HPV-positive cancers. Furthermore, this review will highlight the molecular mechanisms for increased radiation sensitivity using the classical "4 Rs" of radiobiology: repair, reassortment, repopulation, and reoxygenation. First, HPV-positive cancers have increased DNA damage due to increased oxidative stress and impaired DNA damage repair due to the altered activity TP53, p16, TIP60, and other repair proteins. Second, irradiated HPV-positive cancer cells display increased G2/M arrest leading to reassortment of cancer cells in more radiosensitive phases of the cell cycle. In addition, HPV-positive cancers have less radioresistant cancer stem cell subpopulations that may limit their repopulation during radiotherapy. Finally, HPV-positive cancers may also have less hypoxic tumor microenvironments that make these cancers more sensitive to radiation than HPV-negative cells. We will also discuss extrinsic immune and microenvironmental factors enriched in HPV-positive cancers that facilities responses to radiation. Therefore, these potential biological mechanisms may underpin the improved clinical outcomes often observed in these virally induced cancers.

Proton Radiotherapy to Reduce Late Complications in Childhood Head and Neck Cancers

In most childhood head and neck cancers, radiotherapy is an essential component of treatment; however, it can be associated with problematic long-term complications. Proton beam therapy is accepted as a preferred radiation modality in pediatric cancers to minimize the late radiation side effects. Given that childhood cancers are a rare and heterogeneous disease, the support for proton therapy comes from risk modeling and a limited number of cohort series. Here, we discuss the role of proton radiotherapy in pediatric head and neck cancers with a focus on reducing radiation toxicities. First, we compare the efficacy and expected toxicities in proton and photon radiotherapy for childhood cancers. Second, we review the benefit of proton radiotherapy in reducing acute and late radiation toxicities, including risks for secondary cancers, craniofacial development, vision, and cognition. Finally, we review the cost effectiveness for proton radiotherapy in pediatric head and neck cancers. This review highlights the benefits of particle radiotherapy for pediatric head and neck cancers to improve the quality of life in cancer survivors, to reduce radiation morbidities, and to maximize efficient health care use.

Cooperation of genes in HPV16 E6/E7-dependent cervicovaginal carcinogenesis trackable by endoscopy and independent of exogenous estrogens or carcinogens

Human papillomavirus (HPV) infection is necessary but insufficient for progression of epithelial cells from dysplasia to carcinoma-in situ (CIS) to invasive cancer. The combination of mutant cellular and viral oncogenes that regulate progression of cervical cancer (CC) remains unclear. Using combinations of HPV16 E6/E7 (E+), mutant Kras (mKras) (K+) and/or loss of Pten (P-/-), we generated autochthonous models of CC without exogenous estrogen, carcinogen or promoters. Furthermore, intravaginal instillation of adenoCre virus enabled focal activation of the oncogenes/inactivation of the tumor suppressor gene. In P+/+ mice, E6/E7 alone (P+/+E+K-) failed to cause premalignant changes, while mKras alone (P+/+E-K+) caused persistent mucosal abnormalities in about one-third of mice, but no cancers. To develop cancer, P+/+ mice needed both E6/E7 and mKras expression. Longitudinal endoscopies of P+/+E+K+ mice predicted carcinoma development by detection of mucosal lesions, found on an average of 23 weeks prior to death, unlike longitudinal quantitative PCRs of vaginal lavage samples from the same mice. Endoscopy revealed that individual mice differed widely in the time required for mucosal lesions to appear after adenoCre and in the time required for these lesions to progress to cancer. These cancers developed in the transition zone that extends, unlike in women, from the murine cervix to the distal vagina. The P-/-E+K+ genotype led to precipitous cancer development within a few weeks and E6/E7-independent cancer development occurred in the P-/-E-K+ genotype. In the P-/-E+K- genotype, mice only developed CIS. Thus, distinct combinations of viral and cellular oncogenes are involved in distinct steps in cervical carcinogenesis.

Impact of anatomic site of distant metastasis on survival in salivary gland cancers

BACKGROUND

As exemplified in patients with adenoid cystic carcinoma (ACC), metastatic salivary gland cancers display heterogenous behavior. Although anatomic site of metastasis has been suggested to be prognostic for survival in this population, this is not adequately characterized in the current literature.

METHODS

Using the National Cancer Database (NCDB), patients with newly diagnosed metastatic salivary gland cancers with distant metastasis to a single organ were identified.

RESULTS

Eight hundred and fifty-eight patients (n = 284 bone-only, n = 322 lung-only, n = 252 other-site-only) were identified. Anatomic site of distant metastasis was not associated with survival in the cohort as a whole; however, on pre-planned subgroup analysis, lung-only metastasis, relative to bone-only metastasis, was the only factor associated with improved survival in patients with ACC (HR: 0.52, 95%CI: 0.30-0.93, p = 0.029).

CONCLUSIONS

Anatomic site of metastasis is strongly associated with survival in patients with metastatic ACC and should be considered in future studies aiming to optimize therapy in this population.

Prostate Cancer Radiotherapy: Increased Biochemical Control and Late Toxicity in Men With Medication Allergies

Background

Given similarities in the mediators of medication allergy (MA) and tissue response to radiotherapy, we assessed whether outcomes following prostate radiotherapy differ in patients with MAs.

Methods

A total 587 men with known MA history and nonmetastatic prostate cancer underwent radiotherapy from 1989 to 2006. Clinicopathologic and treatment variables were analyzed for association with freedom from biochemical failure (FFBF) and late treatment–related, physician-defined Radiation Therapy Oncology Group gastrointestinal (GI) and genitourinary (GU) toxicity. Covariates identified on univariate analysis for toxicity and disease control were examined on multivariable analysis. All statistical tests were 2-sided, and a P less than .05 was considered statistically significant.

Results

A total of 155 of 587 men (26.4%) had 1 or more MAs, most commonly to penicillin (n = 71), sulfa (n = 35), and aspirin or nonsteroidal antiinflammatory drugs (n = 28). On univariate analysis, men with MAs had superior 10-y FFBF (71.5% vs 63.5%, P = .02) and higher incidence of late GI grade 2 or higher (G2+; 20.6% vs 13.2%, P = .04) and grade 3 or higher (G3+; 7.5% vs 3.9%, P = .08) as well as late GU G2+ (42.5% vs 33.2%, P = .04) and G3+ (7.5% vs 3.0%, P = .02) toxicity than men without MAs. On multivariable analysis, MA history remained a statistically significant predictor of FFBF (hazard ratio [HR] = 0.64, 95% confidence interval [CI] = 0.43 to 0.93, P = .02), late G2+ GI (HR = 1.76, 95% CI = 1.06 to 2.90, P=.03), and G3+ GU (HR = 2.69, 95% CI = 1.16 to 6.27, P = .02) toxicity after controlling for corresponding covariates in each model.

Conclusions

Men with MAs had improved FFBF and increased treatment-related toxicity following radiotherapy for prostate cancer. MA history could be a relevant consideration in the management of men with localized prostate cancer.

Patterns of Care and Survival Outcomes for Odontogenic Cancers

OBJECTIVES

Our understanding of odontogenic cancers is limited primarily to case studies given the rarity of these head and neck neoplasms. Using the National Cancer Database, we report the treatment patterns and survival outcomes for one of the largest cohorts of patients with odontogenic cancers.

METHODS

Patients with odontogenic tumors who did not have metastatic disease and received at least part of their care at the reporting facility were included. Patient and treatment variables were assessed using logistic regression. Survival was assessed using Cox proportional hazard models.

RESULTS

We identified 437 patients with odontogenic cancers, the majority of which had malignant ameloblastoma (n = 203) or odontogenic carcinoma (n = 217). Median follow-up was 44.8 months. On multivariate analysis, improved survival was associated with age <57 years (Hazard ratios [HR] 0.44, P = .012), lower comorbidity scores (HR 0.40, P = .008), surgical resection (HR 0.08, P < .001) and absence of lymph node metastasis (HR 0.23, P < .001). The 5-year overall survival was 87.1% for debulking surgery, 88.6% for radical resection and 26.6% for no surgical resection (P < .001). Lymph node metastases were associated with tumor size ≥5 cm (P = .006), malignant odontogenic histology (P = .025), and moderate/poor differentiation (P < .001).

CONCLUSION

In this large series of odontogenic cancers, any type of surgical resection was associated with improved survival. Lymph node metastases, although infrequent, were associated with significantly worse survival.

LEVEL OF EVIDENCE

Level 3 Laryngoscope, 131:E1496-E1502, 2021.

Machine learning guided adjuvant treatment of head and neck cancer

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Background: A combined analysis of the EORTC 22931 and RTOG 95-01 trials confirmed that patients (pts) with head and neck squamous cell carcinoma (HNSCC) and positive margins or extracapsular extension (ECE) benefit from adjuvant chemoradiotherapy (CRT), but the best treatment of pts with other risk factors is unclear. We hypothesized that deep learning models could identify the margin/ECE negative pts who benefit from CRT. Methods: We abstracted pts from the NCDB diagnosed from 2004-2016 with resected HNSCC who received radiotherapy (RT). We reserved 20% of pts for validation and used the remaining 80% for feature selection and model training. Features were chosen based on independent significance in a Cox proportional hazards model, and included demographics, tumor stage, site, grade, RT dose, and receipt of chemotherapy. HPV status was included, and imputed when unknown. We generated survival predictions with DeepSurv (DS), random survival forest (RSF), and neural network multitask (NNM) models. We consider CRT to be recommended by a model if predicted survival is longer with CRT than RT. We calculated the median overall survival (mOS) difference and hazard ratio (HR) for receipt of treatment in line with model recommendations. This was repeated with inverse probability of treatment weighting (IPTW) to account for confounding. As a comparator, we used the intermediate risk factors in the EORTC (T3-4 except T3N0 larynx, N2-3, LVI, deep nodes with oral / oropharynx cancer) and RTOG (2 involved nodes) trials as decision rules. Results: 36,831 pts from the NCDB met the inclusion criteria. 92% had T3-4 or node positive disease, and 40% received CRT. RTOG, EORTC, DS, NNM, and RSF models recommend CRT for 32%, 74%, 63%, 61%, and 35% of pts. The concordance index in the validation set was 0.696, 0.692, and 0.699 for DS, NNM, and RSF. Treatment according to model recommendations in the validation cohort was associated with a mOS benefit of 18.4 months (7.6 to 29.3, 95% CI) for DS, 20.5 months (8.8 to 32.2, 95% CI) for NNM, and 5.8 months (-6.6 to 18.3, 95% CI) for RSF. Similar results were seen with IPTW. Conclusions: Machine learning models can predict benefit from CRT in margin/ECE negative pts, and outperform treatment according to EORTC or RTOG inclusion criteria in this cohort. External validation of these models is warranted. [Table: see text]

Patterns of Care and Outcomes of Intensity-Modulated Radiotherapy and 3D Conformal Radiotherapy for Early Stage Glottic Cancer: A National Cancer Database Analysis

Early stage glottic cancer has traditionally been treated with 3D conformal radiotherapy (3DCRT). However, intensity-modulated radiotherapy (IMRT) has been recently adopted as an alternative to decrease toxicity. Here, we compared the usage and outcomes of IMRT and 3DCRT for patients with early stage squamous cell carcinoma (SCC) of the glottic larynx. Using the National Cancer Database, we identified patients with Stage I–II SCC of the glottis who received 55–75 Gy using IMRT (n = 1623) or 3DCRT (n = 2696). Median follow up was 42 months with a 5-year overall survival (OS) of 72%. Using a nominal logistic regression, race, ethnicity, year of diagnosis and fraction size were associated with the receipt of IMRT (p < 0.05). Using Kaplan–Meier methods and Cox proportional hazards models as well as a propensity matched cohort, there was no difference in OS for patients who received IMRT versus 3DCRT (hazard ratio (HR), 1.08; 95% confidence interval (95% CI), 0.93–1.26; p = 0.302). However, there was a survival benefit for patients receiving slight hypofractionation as compared to conventional fractionation (HR, 0.78; 95% CI, 0.69–0.92; p = 0.003). IMRT was associated with similar survival as 3DCRT, supporting the implementation of this potentially less toxic modality without compromising survival.

Mevalonate pathway activity as a determinant of radiation sensitivity in head and neck cancer

Radioresistance is a major hurdle in the treatment of head and neck squamous cell carcinoma (HNSCC). Here, we report that concomitant treatment of HNSCCs with radiotherapy and mevalonate pathway inhibitors (statins) may overcome resistance. Proteomic profiling and comparison of radioresistant to radiosensitive HNSCCs revealed differential regulation of the mevalonate biosynthetic pathway. Consistent with this finding, inhibition of the mevalonate pathway by pitavastatin sensitized radioresistant SQ20B cells to ionizing radiation and reduced their clonogenic potential. Overall, this study reinforces the view that the mevalonate pathway is a promising therapeutic target in radioresistant HNSCCs.

Adjuvant chemotherapy following stereotactic body radiotherapy for early stage non-small-cell lung cancer is associated with lower overall: A National Cancer Database Analysis

OBJECTIVES

Adjuvant chemotherapy is routinely offered post-surgical resection for early stage non-small-cell lung cancer (NSCLC) ≥4 cm; however, its role following definitive stereotactic body radiotherapy (SBRT) has not been well defined. We investigated the association between receipt of adjuvant chemotherapy post-SBRT and overall survival (OS) for patients with T1-T3N0M0 NSCLC in the National Cancer Database (NCDB).

MATERIALS AND METHODS

The NCDB was queried for patients with T1-T3N0M0 NSCLC treated with definitive SBRT from 2004 to 2014. The association between non-randomized receipt of adjuvant chemotherapy and OS was analyzed for all patients (n = 24,011) and a propensity-matched cohort (n = 608) using Kaplan-Meier methods and Cox proportional hazard models. A subset analysis was performed for patients with tumors ≥4 cm (n = 2,323).

RESULTS

There were 24,011 patients in the cohort with a median follow-up of 32.5 months. Of these, 322 (1.3%) received adjuvant chemotherapy. Three-year OS was 41.3% with adjuvant chemotherapy compared to 50.6% without adjuvant chemotherapy (p = 0.001). On multivariate analysis, adjuvant chemotherapy was independently associated with higher overall mortality (hazard ratio:1.22, 95% confidence interval:1.06-1.40, p = 0.005). For tumors ≥4 cm, 3-year OS was 38.2% with adjuvant chemotherapy (n = 80) compared to 33.0% without adjuvant chemotherapy (p = 0.81). After propensity-score matching, there was a persistent association between lower OS and adjuvant chemotherapy with those receiving adjuvant chemotherapy (n = 322) having 3-year OS of 41.3% compared to 60.9% without adjuvant chemotherapy (p < 0.0001).

CONCLUSION

Adjuvant chemotherapy following definitive SBRT for T1-3N0M0 NSCLC is associated with lower OS and is not associated with a survival benefit for patients with tumors ≥4 cm.

Overall survival according to immunotherapy and radiation treatment for metastatic non-small-cell lung cancer: a National Cancer Database analysis

Background

Preclinical studies suggest enhanced anti-tumor activity with combined radioimmunotherapy. We hypothesized that radiation (RT) + immunotherapy would associate with improved overall survival (OS) compared to immunotherapy or chemotherapy alone for patients with newly diagnosed metastatic non-small-cell lung cancer (NSCLC).

Methods

The National Cancer Database was queried for patients with stage IV NSCLC receiving chemotherapy or immunotherapy from 2013 to 2014. RT modality was classified as stereotactic radiotherapy (SRT) to intra- and/or extracranial sites or non-SRT external beam RT (EBRT). OS was analyzed using the Kaplan-Meier method and Cox proportional hazards models.

Results

In total, 44,498 patients were included (13% immunotherapy, 46.8% EBRT, and 4.7% SRT). On multivariate analysis, immunotherapy (hazard ratio [HR]:0.81, 95% confidence interval [CI]:0.78–0.83) and SRT (HR:0.78, 95%CI:0.70–0.78) independently associated with improved OS; however, the interaction term for SRT + immunotherapy was insignificant (p = 0.89). For immunotherapy patients, the median OS for no RT, EBRT, and SRT was 14.5, 10.9, and 18.2 months, respectively (p < 0.0001), and EBRT (HR:1.37, 95%CI:1.29–1.46) and SRT (HR:0.78, 95%CI:0.66–0.93) associated with OS on multivariate analysis. In the SRT subset, median OS for immunotherapy and chemotherapy was 18.2 and 14.3 months, respectively (p = 0.004), with immunotherapy (HR:0.82, 95%CI:0.69–0.98) associating with OS on multivariate analysis. Furthermore, for patients receiving SRT, biologically effective dose (BED) > 60 Gy was independently associated with improved OS (HR:0.79, 95%CI:0.70–0.90, p < 0.0001) on multivariate analysis with a significant interaction between BED and systemic treatment (p = 0.008).

Conclusions

Treatment with SRT associated with improved OS for patients with metastatic NSCLC irrespective of systemic treatment. The high survival for patients receiving SRT + immunotherapy strongly argues for evaluation in randomized trials.

Molecular Classification of Lymph Node Metastases Subtypes Predict for Survival in Head and Neck Cancer

PURPOSE

In advanced stage head and neck squamous cell cancers (HNSCC), approximately half of the patients with lymph node metastases (LNM) are not cured. Given the heterogeneous outcomes in these patients, we profiled the expression patterns of LNMs to identify the biological factors associated with patient outcomes.Experimental Design: We performed mRNAseq and miRNAseq on 72 LNMs and 29 matched primary tumors from 34 patients with HNSCC. Clustering identified molecular subtypes in LNMs and in primary tumors. Prediction Analysis of Microarrays algorithm identified a 73-gene classifier that distinguished LNM subtypes. Gene-set enrichment analysis identified pathways upregulated in LNM subtypes.

RESULTS

Integrative clustering identified three distinct LNM subtypes: (i) an immune subtype (Group 1), (ii) an invasive subtype (Group 2), and (iii) a metabolic/proliferative subtype (Group 3). Group 2 subtype was associated with significantly worse locoregional control and survival. LNM-specific subtypes were not observed in matched primary tumor specimens. In HNSCCs, breast cancers, and melanomas, a 73-gene classifier identified similar Group 2 LNM subtypes that were associated with worse disease control and survival only when applied to lymph node sites, but not when applied to other primary tumors or metastatic sites. Similarly, previously proposed prognostic classifiers better distinguished patients with worse outcomes when applied to the transcriptional profiles of LNMs, but not the profiles of primary tumors.

CONCLUSIONS

The transcriptional profiles of LNMs better predict outcomes than transcriptional profiles of primary tumors. The LNMs display site-specific subtypes associated with worse disease control and survival across multiple cancer types.

Combination of radiotherapy and vaccination overcomes checkpoint blockade resistance

The majority of cancer patients respond poorly to either vaccine or checkpoint blockade, and even to the combination of both. They are often resistant to high doses of radiation therapy as well. We examined prognostic markers of immune cell infiltration in pancreatic cancer. Patients with low CD8⁺ T cell infiltration and high PD-L1 expression (CD8⁺ T^loPD-L1^hi) experienced poor outcomes. We developed a mouse tumor fragment model with a trackable model antigen (SIYRYYGL or SIY) to mimic CD8⁺ T^loPD-L1^hi cancers. Tumors arising from fragments contained few T cells, even after vaccination. Fragment tumors responded poorly to PD-L1 blockade, SIY vaccination or radiation individually. By contrast, local ionizing radiation coupled with vaccination increased CD8⁺ T cell infiltration that was associated with upregulation of CXCL10 and CCL5 chemokines in the tumor, but demonstrated modest inhibition of tumor growth. The addition of an anti-PD-L1 antibody enhanced the effector function of tumor-infiltrating T cells, leading to significantly improved tumor regression and increased survival compared to vaccination and radiation. These results indicate that sequential combination of radiation, vaccination and checkpoint blockade converts non-T cell-inflamed cancers to T cell-inflamed cancers, and mediates regression of established pancreatic tumors with an initial CD8⁺ T^loPD-L1^hi phenotype. This study has opened a new strategy for shifting “cold” to hot tumors that will respond to immunotherapy.

Differences in Survival With Surgery and Postoperative Radiotherapy Compared With Definitive Chemoradiotherapy for Oral Cavity Cancer: A National Cancer Database Analysis

Importance

Because locally advanced oral cavity squamous cell carcinoma (OCSCC) is often treated with surgery followed by postoperative radiotherapy (S+PORT), the effectiveness of organ preservation with concurrent chemoradiotherapy (CRT) remains unclear.

Objective

To compare the differences in survival between patients with locally advanced OCSCC treated with S+PORT or CRT.

Design, Setting, and Participants

Using the National Cancer Database, this study compared 6900 patients with stage III to IVA OCSCC treated with S+PORT and CRT from 2004 through 2012 at academic and community-based cancer clinics. Comparisons were made using Kaplan-Meier methods and Cox proportional hazards regression models using the entire cohort and a propensity score-matched cohort of 2286 patients.

Main Outcomes and Measures

Overall survival (OS).

Results

Of the 6900 study patients, 4809 received S+PORT (3080 male [64.0%] and 1792 [36.0%] female) and 2091 received CRT (1453 male [69.5%] and 638 [30.5%] female). Median follow-up for the entire group was 23.0 months overall but was shorter for patients receiving CRT (17.3-month) vs S+PORT (25.6 months). Patients receiving CRT were more likely to be older than 60 years, treated before 2007, live within 10 miles of the treating facility, treated at nonacademic centers, have more comorbidities, have T3 to T4a tumors, and have N2a to N2c nodal disease. Propensity score matching identified cohorts of patients with similar clinical variables. S+PORT was associated with improved survival among all patients (3-year OS: 53.9% for S+PORT vs 37.8% for CRT; difference = 16.1%; 95% CI, 13.6%-18.6%) and in the propensity score-matched cohort (3-year OS: 51.8% for S+PORT vs 39.3% for CRT; difference = 11.9%; 95% CI, 7.8%-16.0%). S+PORT was associated with improved survival among patients with T3 to T4a tumors (3-year OS: 49.7% for S+PORT vs 36.0% for CRT; difference = 16.1%; 95% CI, 13.6%-18.6%) but was not associated with improved survival among patients with T1 to T2 tumors (3-year OS: 59.1% for S+PORT vs 53.5% for CRT; difference = 5.6%; 95% CI, -3.1% to 14.3%).

Conclusions and Relevance

Compared with CRT, S+PORT was associated with improved survival for locally advanced OCSCCs, especially in T3 to T4a disease. These data support the use of surgery as the initial treatment modality for operable OCSCCs.

Optima: A phase II dose and volume de-escalation trial for high- and low-risk HPV+ oropharynx cancers

6066

Background: In this prospective phase II de-escalation study, we used induction chemotherapy to identify favorable HPV+ oropharyngeal cancer (OPC) pts, including those with high-risk tumors, and applied significantly lower radiation or chemoradiation doses than previously reported. Methods: Pts with HPV+ OPC were classified as low-risk (≤T3, ≤N2B, ≤10 PYH) or high-risk (T4 or ≥N2C or > 10 PYH). Pts received 3 cycles of carboplatin (AUC 6, D1) and nab-paclitaxel (100 mg/m2, D1/8/15). 1) Low-risk pts with ≥50% response received low-dose radiotherapy alone to 50Gy (RT50). 2) Low-risk pts with 30-50% response OR high-risk pts with ≥50% response received low-dose chemoradiotherapy to 45Gy (CRT45). 3) All other ( = poor response) pts received regular-dose CRT (CRT75). All pts also received de-escalated RT volumes limited to the first echelon of uninvolved nodes. CRT consisted of paclitaxel, 5-FU, hydroxyurea, and 1.5Gy twice daily RT every other week. Primary site biopsy and neck dissection were performed only after de-escalated treatment (RT50, CRT45) for pathologic confirmation. The primary endpoint was 2-year PFS. Secondary endpoints included pathologic complete response (pCR) rate and toxicity. Results: 62 pts were enrolled. 28 pts (45.2%) were low-risk and 34 pts (54.8%) were high-risk. 71.4% of low-risk pts received RT50 and 21.4% received CRT45. 70.6% of high-risk pts received CRT45. The pCR rate was 94.4% after RT50 and 92.3% after CRT45. Median follow-up is 1 year. The 2-year PFS and OS were both 100% for low-risk pts, and 91.6% and 97.0% for high-risk pts. Significant decrease in the rates of grade ≥3 mucositis (15.8% RT50, 46.4% CRT45, 60.0% CRT75, p = .033) and grade ≥3 dermatitis (0% RT50, 21.4% CRT45, 30.0% CRT75, p = .056) were observed. PEG-tube dependency was improved at 3 months (0% RT50, 14.8% CRT45, 70.0% CRT75, p < .001) and 6 months (0% RT50, 3.7% CRT45, 20.0% CRT75, p = .066) post-treatment. Conclusions: Favorable response to induction chemotherapy appears to be a powerful biomarker for dose and volume de-escalation with 50Gy RT or 45Gy CRT. Outstanding survival and high pCR rates suggest that completion neck dissection may not be necessary. Toxicity and functional outcomes are significantly improved. Clinical trial information: NCT02258659.

Weekly versus every-three-weeks platinum-based chemoradiation regimens for head and neck cancer

Background

The majority of chemoradiation (CRT) trials for locally advanced head and neck squamous cell carcinoma (HNSCC) have relied on platinum-based chemotherapy regimens administered every-3-weeks. However, given the increased utilization of weekly platinum regimens, it remains unclear how different chemotherapy schedules compare regarding efficacy and toxicity.

Methods

We retrospectively identified 212 patients with HNSCC who were treated at a single academic medical center with concurrent platinum-based CRT given weekly (N = 68) or every-three-weeks (N = 144). JMP version 10 (SAS Institute) was used for statistical analysis. Discrete variables were compared with the chi-square test and differences in the medians were assessed using the Wilcoxon test. Survival curves were constructed using the Kaplan-Meier method and significance was assessed using the log rank test. For univariate analysis and multivariate analysis, we used Cox proportional hazard or logistic regression models to compare differences in survival or differences in categorical variables, respectively.

Results

Patients receiving weekly platinum regimens were more likely to be older (median age 61.4 vs. 55.5 y; P < .001), have high or very high Charlson comorbidity index (45.6% vs. 27.8%; P = .01), and receive carboplatin-based chemotherapy (6.3% vs. 76.5%; P < .001). Weekly and every-3-week platinum regimens had similar locoregional control (HR 1.10; 95% CI 0.63–1.88; P = .72), progression-free survival (HR 1.13; 95% CI 0.75–1.69; P = .55), and overall survival (HR 1.11; 95% CI 0.64–1.86; P = .71). Every-3-weeks platinum regimens were associated with increased days of hospitalization (median: 3 days vs. 0 days; P = .03) and acute kidney injury (AKI) during radiotherapy (50.0% vs. 22.1%; P < .001). On multivariate analysis, AKI was significantly associated with every-3-weeks regimens (OR: 24.38; 95% CI 3.00–198.03; P = .003) and high comorbidity scores (OR: 2.74; 95% CI 2.15–5.99; P = .01).

Conclusions

Our results suggest that every-3-weeks and weekly platinum-containing CRT regimens have similar disease control but weekly platinum regimens are associated with less acute toxicity.

Electronic supplementary material

The online version of this article (doi:10.1186/s40463-016-0175-x) contains supplementary material, which is available to authorized users.

Abstract LB-251: Radiotherapy sensitizes pancreatic cancer to immunotherapy by promoting T cell infiltration

Pancreatic cancer patients often fail to respond to immunotherapy, such as vaccines or checkpoint inhibitors. It is unknown if an immune phenotype predicts the efficacy of immunotherapy for pancreatic cancer and what standard modalities are required to facilitate the response of pancreatic cancer to immunotherapy. We examined prognostic markers of immune cell infiltration in pancreatic cancer. Pancreatic cancer patients with low CD8+ T cell infiltration and high PD-L1 expression (CD8+ TloPD-L1hi) experienced worse outcomes compared to patients whose tumors demonstrate CD8+ TloPD-L1lo, CD8+ ThiPD-L1hi or CD8+ ThiPD-L1lo profiles. To understand how to improve tumor control in CD8+ TloPD-L1hi pancreatic cancers, we developed a mouse tumor fragment model with a trackable model antigen (SIYRYYGL or SIY) to mimic CD8+ TloPD-L1hi pancreatic cancers. Similar to pancreatic cancers, tumors arising from fragments contained few T cells, even after vaccination. Fragment tumors responded poorly to PD-L1 blockade, SIY vaccination or radiation as individual treatments. By contrast, local ionizing radiation coupled with vaccination increased CD8+ T cell infiltration that was associated with upregulation of CXCL10 and CCL5 chemokines in the tumor, but demonstrated modest inhibition of tumor growth. The addition of an anti-PD-L1 antibody enhanced the effector function of tumor-infiltrating T cells, leading to significantly improved tumor regression and increased survival compared to vaccination and radiation. These results indicate that combination of radiation, vaccination and checkpoint blockade could convert non-T cell-inflamed cancers to T cell-inflamed cancers, and thus effectively treat established pancreatic tumors with an initial CD8+ TloPD-L1hi phenotype. This suggests a novel immunostimulatory role for radiotherapy in the treatment of pancreatic cancer.

Citation Format: Wenxin Zheng, Kinga B. Skowron, Jukes P. Namm, Byron Burnette, Christian Fernandez, Ainhoa Arina, Hua Liang, Michael T. Spiotto, Mitchell C. Posner, Yang-Xin Fu, Ralph R. Weichselbaum. Radiotherapy sensitizes pancreatic cancer to immunotherapy by promoting T cell infiltration. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr LB-251.

Hospitalizations of more than 5 days predict for worse outcomes after radiotherapy for head and neck cancer

BACKGROUND

Patients undergoing chemoradiation for head and neck squamous cell carcinoma (HNSCC) are predisposed to unplanned hospitalizations.

OBJECTIVE

To assess the factors associated with prolonged hospitalization and its impact on patient outcomes.

METHODS

We assessed the outcomes of patients hospitalized for ≥5 days or <5 days in 251 patients with advanced HNSCC who were undergoing radiotherapy during 2000-2012.

RESULTS

Patients who had been hospitalized for ≥5 days were more likely to be admitted for infection, acute renal failure, and/or dehydration. We found no other patient, tumor, or treatment characteristics associated with prolonged hospitalizations. Hospitalizations of ≥5 days were associated with a higher incidence of delays in radiotherapy (RT; odds ratio [OR], 2.49; 95% confidence index [CI], 1.09-5.69; 𝑃 = .03) and worse performance status after RT (OR, 5.76; 95% CI, 1.85-18.38; 𝑃 = .003). On multivariate analysis, hospitalization of ≥5 days predicted for worse local-regional control (hazard ratio [HR], 1.85; 95% CI, 1.08-3.17; 𝑃 = .03) and time to treatment failure (HR, 1.64; 95% CI, 1.03-2.61; 𝑃 = .04), and performance status after RT predicted for worse local-regional control, time to treatment failure, progression-free survival, and overall survival.

LIMITATIONS

As a retrospective review, we report only hypothesis-generating observations, which may have been affected by having incomplete patient information.

CONCLUSIONS

Hospitalizations of ≥5 days was associated with infections and/or dehydration and predicted for worse disease control. Our results suggest that patients may benefit from efforts to reduce hospitalization length by minimizing precipitators of hospitalizations as well as interventions to reduce the length of hospital stays.

Loss of E2F1 Extends Survival and Accelerates Oral Tumor Growth in HPV-Positive Mice

The Human Papillomavirus (HPV) is associated with several human cancers, including head and neck squamous cell carcinomas (HNSCCs). HPV expresses the viral oncogene E7 that binds to the retinoblastoma protein (RB1) in order to activate the E2F pathway. RB1 can mediate contradictory pathways-cell growth and cell death via E2F family members. Here, we assessed the extent to which E2F1 mediates lethality of HPV oncogenes. Ubiquitous expression of the HPV oncogenes E6 and E7 caused lethality in mice that was associated with focal necrosis in hepatocytes and pancreatic tissues. Furthermore, all organs expressing HPV oncogenes displayed up-regulation of several E2F1 target genes. The E2F1 pathway mediated lethality in HPV-positive mice because deletion of E2F1 increased survival of mice ubiquitously expressing HPV oncogenes. E2F1 similarly functioned as a tumor suppressor in HPV-positive oral tumors as tumors grew faster with homozygous loss of E2F1 compared to tumors with heterozygous loss of E2F1. Re-expression of E2F1 caused decreased clonogenicity in HPV-positive cancer cells. Our results indicate that HPV oncogenes activated the E2F1 pathway to cause lethality in normal mice and to suppress oral tumor growth. These results suggest that selective modulation of the E2F1 pathway, which is activated in HPV tumors, may facilitate tumor regression.

Notch1 Activation or Loss Promotes HPV-Induced Oral Tumorigenesis

Viral oncogene expression is insufficient for neoplastic transformation of human cells, so human papillomavirus (HPV)-associated cancers will also rely upon mutations in cellular oncogenes and tumor suppressors. However, it has been difficult so far to distinguish incidental mutations without phenotypic impact from causal mutations that drive the development of HPV-associated cancers. In this study, we addressed this issue by conducting a functional screen for genes that facilitate the formation of HPV E6/E7-induced squamous cell cancers in mice using a transposon-mediated insertional mutagenesis protocol. Overall, we identified 39 candidate driver genes, including Notch1, which unexpectedly was scored by gain- or loss-of-function mutations that were capable of promoting squamous cell carcinogenesis. Autochthonous HPV-positive oral tumors possessing an activated Notch1 allele exhibited high rates of cell proliferation and tumor growth. Conversely, Notch1 loss could accelerate the growth of invasive tumors in a manner associated with increased expression of matrix metalloproteinases and other proinvasive genes. HPV oncogenes clearly cooperated with loss of Notch1, insofar as its haploinsufficiency accelerated tumor growth only in HPV-positive tumors. In clinical specimens of various human cancers, there was a consistent pattern of NOTCH1 expression that correlated with invasive character, in support of our observations in mice. Although Notch1 acts as a tumor suppressor in mouse skin, we found that oncogenes enabling any perturbation in Notch1 expression promoted tumor growth, albeit via distinct pathways. Our findings suggest caution in interpreting the meaning of putative driver gene mutations in cancer, and therefore therapeutic efforts to target them, given the significant contextual differences in which such mutations may arise, including in virus-associated tumors.

Effect of postradiotherapy neck dissection on nonregional disease sites

IMPORTANCE

After chemoradiation for head and neck cancer, more than 90% of patients who achieve a complete clinical response on imaging have their disease regionally controlled without postradiotherapy neck dissections (PRNDs). Because several groups have reported that lymph node involvement also predicts failure at both the primary and distant sites, the extent to which PRND affects nonregional sites of disease remains unclear.

OBJECTIVE

To evaluate how PRND affects local control (LC) and distant control in patients who achieve a complete clinical response.

DESIGN, SETTING, AND PARTICIPANTS

We retrospectively reviewed 287 patients (74 of whom underwent PRND) from the University of Illinois at Chicago Medical Center who were treated for stage III/IV disease with definitive chemoradiation from January 1, 1990, through December 31, 2012.

INTERVENTIONS

Chemoradiation followed by lymph node dissection or observation.

MAIN OUTCOMES AND MEASURES

End points evaluated included LC, regional control, freedom from distant metastasis, progression-free survival (PFS), and overall survival using first-failure analysis.

RESULTS

Patients with advanced nodal disease (stage N2b or greater; n = 176) had improved PFS (74.6% vs 39.1%; P < .001), whereas patients with lesser nodal disease had similar PFS. For patients with advanced nodal disease, PRND improved 2-year LC (85.5% vs 53.5%; P < .001), locoregional control with PRND (78.9% vs 45.7%; P < .001), freedom from distant metastasis (79.5% vs 67.5%; P = .03), and overall survival (84.5% vs 61.7%; P = .004) but not regional control (96.9% vs 90.1%; P = .21). The benefit in LC (87.4% vs 66.2%; P = .02) and PFS (80.7% vs 53.4%; P = .01) persisted for those with negative posttreatment imaging results who underwent PRND. On univariate analysis, PRND, alcohol use, nodal stage, and chemoradiation significantly affected 2-year LC and/or PFS. On multivariate analysis, PRND remained strongly prognostic for 2-year LC (hazard ratio, 0.22; 95% CI, 0.07-0.54; P < .001) and PFS (hazard ratio, 0.42; 95% CI, 0.23-0.74; P = .002).

CONCLUSIONS AND RELEVANCE

Postradiotherapy neck dissection improved control of nonregional sites of disease in patients with advanced nodal disease who achieved a complete response after chemoradiation. Thus, PRND may affect the control of nonnodal sites through possible mechanisms, such as clearance of incompetent lymphatics and prevention of reseeding of the primary and distant sites.

Racial parities in outcomes after radiotherapy for head and neck cancer

BACKGROUND

Although black patients experience worse outcomes after treatment for squamous cell carcinoma of the head and neck (HNSCC), these conclusions were based on populations in which blacks comprised a minority of patients. The objective of the current study was to determine the impact of race on outcomes in patients with HNSCC who received radiotherapy at an institution in which blacks comprised the majority of patients.

METHODS

In this retrospective cohort study, the authors reviewed 366 black patients and 236 white patients who had nonmetastatic HNSCC for which they received radiotherapy between 1990 and 2012. The primary study outcome measures were locoregional control, freedom from distant metastasis, progression-free survival, and overall survival.

RESULTS

The median follow-up was 18.3 months for all patients. The 2-year locoregional control rate was 71.9% for black patients compared with 64.2% for white patients (hazard ratio, 0.72; P=.03). There was no difference between blacks and whites regarding 2-year freedom from distant metastasis, progression-free survival, or overall survival. Among the patients who had stage III through IVB disease, blacks and whites had similar outcomes. On multivariate analysis, race was not statistically significant for locoregional control, freedom from distant metastasis, progression-free survival, or overall survival. Despite these similar outcomes, black patients had worse socioeconomic factors and increased comorbidities but had similar treatment compliance compared with white patients.

CONCLUSIONS

With more adverse prognostic factors, black patients experienced oncologic outcomes similar to the outcomes of white patients after receiving radiotherapy for HNSCC. The current data suggest that centers that treat large percentages of minority patients who receive radiotherapy for HNSCCs may overcome existing health care disparities through improved treatment compliance.

Animal models to study the mutational landscape for oral cavity and oropharyngeal cancers

OBJECTIVES

Cancer is likely caused by alterations in gene structure or expression. Recently, next generation sequencing has documented mutations in 106 head and neck squamous cell cancer genomes, suggesting several new candidate genes. However, it remains difficult to determine which mutations directly contributed to cancer. Here, summarize the animal models which have already validated and may test cancer causing mutations identified by next generation sequencing approaches.

MATERIAL AND METHODS

We reviewed the existing literature on genetically engineered mouse models and next generation sequencing (NGS), as it relates to animal models of squamous cell cancers of the head and neck (HNSCC) in PubMed.

RESULTS

NSG has identified an average of 19 to 130 distinct mutations per HNSCC specimen. While many mutations likely had biological significance, it remains unclear which mutations were essential to, or "drive," carcinogenesis. In contrast, "passenger" mutations also exist that provide no selection advantage. The genes identified by NGS included p53, RAS, Human Papillomavirus oncogenes, as well as novel genes such as NOTCH1, DICER and SYNE1,2. Animal models of HNSCC have already validated some of these common gene mutations identified by NGS.

CONCLUSIONS

The advent of next generation sequencing will provide new leads to the genetic changes occurring in squamous cell cancers of the head and neck. Animal models will enable us to validate these new leads in order to better elucidate the biology of squamous cell cancers of the head and neck.

Spleen cells from young but not old immunized mice eradicate large established cancers

PURPOSE

Solid tumors that have grown two weeks or longer in mice and have diameters larger than 1 cm are histologically indistinguishable from autochthonous human cancers. When experimental tumors reach this clinically relevant size, they are usually refractory to most immunotherapies but may be destroyed by adoptive T-cell transfer. However, TCR-transgenic T cells and/or tumor cells overexpressing antigens are frequently used in these experiments. Here we studied the requirements for destroying clinical size, unmanipulated 8101 tumors by adoptive cell therapy.

EXPERIMENTAL DESIGN

8101 arose in an old mouse after chronic exposure to UV light. A cancer line was established, which was never serially transplanted. The immunodominant CD8(+) T cell-recognized antigen of this tumor is caused by a somatic tumor-specific mutation in the RNA helicase p68. 8101 tumors were treated with spleen cells from young naive, or young and old immunized mice to ascertain the characteristics of immune cells that lead to rejection.

RESULTS

Here we show that the mutant p68 peptide has an exceptionally high affinity to the presenting MHC class I molecule K(b) and that spleen cells from immunized young syngeneic mice adoptively transferred to Rag(-/-) or cancer-suppressed euthymic mice eradicate 8101 tumors larger than 1 cm in average diameter and established for several weeks. Spleen cells from naive young mice or from old and boosted (reimmunized) mice were ineffective.

CONCLUSIONS

Relapse-free destruction of large and long-established tumors expressing a genuine very high-affinity tumor-specific antigen can be achieved by using adoptive transfer of lymphocytes from immunized young individuals.

Imaging the unfolded protein response in primary tumors reveals microenvironments with metabolic variations that predict tumor growth

Cancer cells exist in harsh microenvironments that are governed by various factors, including hypoxia and nutrient deprivation. These microenvironmental stressors activate signaling pathways that affect cancer cell survival. While others have previously measured microenvironmental stressors in tumors, it remains difficult to detect the real-time activation of these downstream signaling pathways in primary tumors. In this study, we developed transgenic mice expressing an X-box binding protein 1 (XBP1)-luciferase construct that served as a reporter for endoplasmic reticulum (ER) stress and as a downstream response for the tumor microenvironment. Primary mammary tumors arising in these mice exhibited luciferase activity in vivo. Multiple tumors arising in the same mouse had distinct XBP1-luciferase signatures, reflecting either higher or lower levels of ER stress. Furthermore, variations in ER stress reflected metabolic and hypoxic differences between tumors. Finally, XBP1-luciferase activity correlated with tumor growth rates. Visualizing distinct signaling pathways in primary tumors reveals unique tumor microenvironments with distinct metabolic signatures that can predict for tumor growth.