Outcomes of Post-Operative Treatment with Concurrent Chemoradiotherapy (CRT) in High-Risk Resected Oral Cavity Squamous Cell Carcinoma (OCSCC): A Multi-Institutional Collaboration

Adjuvant chemoradiation (CRT), with high-dose cisplatin remains standard treatment for oral cavity squamous cell carcinoma (OCSCC) with high-risk pathologic features. We evaluated outcomes associated with different cisplatin dosing and schedules, concurrent with radiation (RT), and the effect of cumulative dosing of cisplatin. An IRB-approved collaborative database of patients (pts) with primary OCSCC (Stage I–IVB AJCC 7th edition) treated with primary surgical resection between January 2005 and January 2015, with or without adjuvant therapy, was established from six academic institutions. Patients were categorized by cisplatin dose and schedule, and resultant groups compared for demographic data, pathologic features, and outcomes by statistical analysis to determine disease free survival (DFS) and freedom from metastatic disease (DM). From a total sample size of 1282 pts, 196 pts were identified with high-risk features who were treated with adjuvant CRT. Administration schedule of cisplatin was not significantly associated with DFS. On multivariate (MVA), DFS was significantly better in patients without perineural invasion (PNI) and in those receiving ≥200 mg/m² cisplatin dose (p < 0.001 and 0.007). Median DFS, by cisplatin dose, was 10.5 (<200 mg/m²) vs. 20.8 months (≥200 mg/m²). Our analysis demonstrated cumulative cisplatin dose ≥200 mg/m² was associated with improved DFS in high-risk resected OCSCC pts.

Critical Review and Consensus Statement for Neural Monitoring in Otolaryngologic Head, Neck, and Endocrine Surgery

BACKGROUND

Enhancing patient outcomes in an array of surgical procedures in the head and neck requires the maintenance of complex regional functions through the protection of cranial nerve integrity. This review and consensus statement cover the scope of cranial nerve monitoring of all cranial nerves that are of practical importance in head, neck, and endocrine surgery except for cranial nerves VII and VIII within the temporal bone. Complete and applied understanding of neurophysiologic principles facilitates the surgeon's ability to monitor the at-risk nerve.

METHODS

The American Academy of Otolaryngology-Head and Neck Surgery (AAO-HNS) identified the need for a consensus statement on cranial nerve monitoring. An AAO-HNS task force was created through soliciting experts on the subject. Relevant domains were identified, including residency education, neurophysiology, application, and various techniques for monitoring pertinent cranial nerves. A document was generated to incorporate and consolidate these domains. The panel used a modified Delphi method for consensus generation.

RESULTS

Consensus was achieved in the domains of education needs and anesthesia considerations, as well as setup, troubleshooting, and documentation. Specific cranial nerve monitoring was evaluated and reached consensus for all cranial nerves in statement 4 with the exception of the spinal accessory nerve. Although the spinal accessory nerve's value can never be marginalized, the task force did not feel that the existing literature was as robust to support a recommendation of routine monitoring of this nerve. In contrast, there is robust supporting literature cited and consensus for routine monitoring in certain procedures, such as thyroid surgery, to optimize patient outcomes.

CONCLUSIONS

The AAO-HNS Cranial Nerve Monitoring Task Force has provided a state-of-the-art review in neural monitoring in otolaryngologic head, neck, and endocrine surgery. The evidence-based review was complemented by consensus statements utilizing a modified Delphi method to prioritize key statements to enhance patient outcomes in an array of surgical procedures in the head and neck. A precise definition of what actually constitutes intraoperative nerve monitoring and its benefits have been provided.

Use of Preoperative Imaging in Primary Hyperparathyroidism

CONTEXT

Preoperative imaging is performed routinely to guide surgical management in primary hyperparathyroidism, but the optimal imaging modalities are debated.

OBJECTIVE

Our objectives were to evaluate which imaging modalities are associated with improved cure rate and higher concordance rates with intraoperative findings. A secondary aim was to determine whether additive imaging is associated with higher cure rate.

DESIGN, SETTING, AND PATIENTS

This is a retrospective cohort review of 1485 adult patients during a 14-year period (2004-2017) at an academic tertiary referral center that presented for initial parathyroidectomy for de novo primary hyperparathyroidism.

MAIN OUTCOME MEASURES

Surgical cure rate, concordance of imaging with operative findings, and imaging performance.

RESULTS

The overall cure rate was 94.1% (95% confidence interval, 0.93-0.95). Cure rate was significantly improved if sestamibi/single-photon emission computed tomography (SPECT) was concordant with operative findings (95.9% vs. 92.5%, P = 0.010). Adding a third imaging modality did not improve cure rate (1 imaging type 91.8% vs. 2 imaging types 94.4% vs. 3 imaging types 87.2%, P = 0.59). Despite having a low number of cases (n = 28), 4-dimensional (4D) CT scan outperformed (higher sensitivity, specificity, positive predictive value, negative predictive value) all imaging modalities in multiglandular disease and double adenomas, and sestamibi/SPECT in single adenomas.

CONCLUSIONS

Preoperative ultrasound combined with sestamibi/SPECT were associated with the highest cure and concordance rates. If pathology was not found on ultrasound and sestamibi/SPECT, additional imaging did not improve the cure rate or concordance. 4D CT scan outperformed all imaging modalities in multiglandular disease and double adenomas, and sestamibi/SPECT in single adenomas, but these findings were underpowered.

Hormonal Outcomes Following Hemithyroidectomy

OBJECTIVE

To assess hormonal outcomes and thyroid hormone (TH) replacement after hemithyroidectomy (HT).

STUDY DESIGN

Retrospective chart review.

SETTING

Quaternary care hospital system.

METHODS

A retrospective analysis was performed on patients who had an HT at Cleveland Clinic between 2000 and 2010 with outcomes assessed up to 5 years post-HT. Patients with overt hypothyroidism (OH; thyroid-stimulating hormone [TSH] >10 mIU/L, TSH >4.2 mIU/L on thyroid hormone [TH]), subclinical hypothyroidism (SH; TSH >4.2-10 mIU/L, no TH), or euthyroidism (EU; TSH 0.4-4.2 mIU/L, no TH) were compared. Patients with SH who returned to EU were compared to those who continued to have SH. For immediate start on TH, a receiver operating characteristic analysis was performed to determine dosage of TH above which suppression of TSH <0.4 mIU/L was predicted.

RESULTS

We identified 335 patients (average age 51 years, 78% female, median follow-up of 50 months). Of the 210 not immediately started on TH, 32.4% were OH, 13.3% were SH, and 54.3% were EU. EU patients were younger (48 years), had more remaining gland, were less likely to have lymphocytic infiltrate, and had a lower preoperative TSH (1.2 mIU/L). In the SH group, 58.3% of patients normalized their TSH. With immediate TH start, 45% developed suppressed TSH. Those on LT4 >1.05 mcg/kg/d were more likely to suppress (sensitivity 89%).

CONCLUSION

Most patients post-HT will remain EU, and immediate start of TH may lead to TSH suppression. Those with SH may ultimately normalize TSH. These findings together suggest that observation may be a better option than TH replacement after HT.

Identifying an oligometastatic phenotype in HPV-associated oropharyngeal squamous cell cancer: Implications for clinical trial design

OBJECTIVES

Patients with human papillomavirus (HPV) associated squamous cell carcinoma of the oropharynx (SCC-OP) have improved overall survival (OS) after distant metastasis (DM) compared to HPV negative patients. These patients may be appropriate candidates for enrollment on clinical trials evaluating the efficacy of metastasis-directed therapy (MDT). This study seeks to identify prognostic factors associated with OS after DM, which could serve as enrollment criteria for such trials.

MATERIALS AND METHODS

From an IRB approved multi-institutional database, we retrospectively identified patients with HPV/p16 positive SCC-OP diagnosed between 2001 and 2018. Patterns of distant failure were assessed, including number of lesions at diagnosis and sites of involvement. The primary outcome was OS after DM. Prognostic factors for OS after DM were identified with Cox proportional hazards. Stepwise approach was used for multivariable analysis.

RESULTS

We identified 621 patients with HPV-associated SCC-OP, of whom 82 (13.2%) were diagnosed with DM. Median OS after DM was 14.6 months. On multivariable analysis, smoking history and number of lesions were significantly associated with prolonged OS. Median OS after DM by smoking (never vs ever) was 37.6 vs 11.2 months (p = 0.006), and by lesion number (1 vs 2-4 vs 5 or more) was 41.2 vs 17.2 vs 10.8 months (p = 0.007).

CONCLUSION

Among patients with newly diagnosed metastatic HPV-associated SCC-OP, lesion number and smoking status were associated with significantly prolonged overall survival. These factors should be incorporated into the design of clinical trials investigating the utility of MDT, with or without systemic therapy, in this population.

Evaluating compliance with process-related quality metrics and survival in oral cavity squamous cell carcinoma: Multi-institutional oral cavity collaboration study

BACKGROUND

Process-related measures have been proposed as quality metrics in head and neck cancer care. A recent single-institution study identified four key metrics associated with increased survival. This study sought to validate the association of these quality metrics with survival in a multi-institutional cohort.

METHODS

Multicenter retrospective study of patients with oral cavity squamous cell (1/2005-1/2015). Baseline patient and disease characteristics and compliance with quality metrics was evaluated. Association between compliance with quality metrics with overall survival (OS), disease-free survival (DFS), and disease-specific survival (DSS) was evaluated using Cox proportional hazards models.

RESULTS

Failure to comply with two or more of the quality metrics was associated with worse OS, DFS, and DSS. Adherence to all or all but one of the quality metrics was found to be associated with improved survival.

CONCLUSIONS

Process-related quality metrics are associated with increased survival in patients with oral cavity squamous cell carcinoma in a multi-institutional cohort.

Single-institute outcomes of palliative chemotherapy in metastatic head and neck squamous cell carcinoma (HNSCC)

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Background: Distantly metastatic HNSCC carries a poor prognosis with limited palliative systemic treatment options and a paucity of literature examining factors impacting outcomes of such therapy. We sought to evaluate characteristics conferring more favorable responses to frontline palliative systemic therapy after distant failure (DF). Methods: From an IRB-approved database, we identified 332 pts with metastatic HNSCC treated from 1999 to 2019. Pts with locoregional HNSCC who developed DF and subsequently were treated with palliative systemic therapy were included. Pts were categorized by disease factors, and outcomes were analyzed for progression-free survival (PFS) and overall survival (OS) with Kaplan-Meier curves and log-rank p-values. Results: A total of 85 pts were identified with median age 59.5 years (37-89); 82.4% male, 90.6% Caucasian, 52.9% with > 10 pack-years tobacco use history. Oropharynx primary was the most common site (36.5%) followed by oral cavity (23.5%). All 31 oropharynx cancer pts were HPV-related. Sixty-six pts initially received definitive chemoradiotherapy, with 43 receiving concurrent radiosensitizing cisplatin. Median time to DF was 15 months (m). Thirty pts (35.3%) had concurrent locoregional failure with DF. 62.4% had only one metastatic organ site, with lung-only metastasis in 43.5%. Carboplatin/paclitaxel was the most commonly used frontline palliative chemotherapy (50.6%); 22.4% received frontline nivolumab or pembrolizumab, and 9.4% were treated with frontline platinum/5-FU/cetuximab (9.4%). 63.5% of pts achieved a best response of stable disease or better with frontline therapy. At two years after initial DF, 6 pts (7%) were disease-free. Sixteen pts were alive at last follow-up. After DF, median PFS was 6.5 m and median OS was 10.6 m. On univariate analysis, HPV-related disease was associated with increased PFS (9.5 vs 5.1 m, p < 0.0001) and increased OS (21.1 vs 7.7 m, p < 0.0001). Pts with one metastatic organ site had better OS (11.0 vs 6.2 m, p = 0.047). There was a trend of increased OS with lung-only metastasis (14.4 vs 7.7 m, p = 0.0776), and absence of concurrent locoregional failure (10.8 vs 8.3 m, p = 0.1153). Conclusions: Our results demonstrate that HPV-related metastatic HNSCC is associated with a statistically significant increased PFS and OS. Additionally, there was a trend of increased OS with lower locoregional and distant metastatic burden at DF though statistical significance was not achieved.

Selection of patients for surveillance imaging after radiotherapy for squamous cell carcinoma of oral cavity and oropharynx

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Background: NCCN guidelines do not recommend routine surveillance imaging for distant failure (DF) after definitive treatment of head & neck squamous cell carcinoma (SCC). We hypothesized that there exists a subset of patients with sufficiently high enough risk for DF to benefit from surveillance imaging. This study attempts to define high risk cohorts of oropharynx (OP) and oral cavity (OC) patients. Methods: A retrospective review was conducted of patients with SCC of the OP or OC at a single tertiary care institution from 1994-2019. Patients were staged according to AJCC 7th edition and included in this study if they completed definitive-intent treatment and received 60 Gray or higher of radiotherapy (RT). Local, regional, and distant failure were estimated with cumulative incidence. Univariable & multivariable risk factors for DF were identified with Fine & Gray competing risk regression. Significant variables were compiled to calculate a risk score. Results: 863 patients were included (676 OP/187 OC). OC patients were 60.4% male, median age 61, with median follow up of 77.5 months. Smoking status was 27.3% current, 44.4% former, 28.3% never, with 30 median pack years. Disease was 57.3% T1-2, 42.7% T3-4, 55.6% N0-2a, 44.4% N2b-3. 94.1% had surgery & 34.3% had concurrent systemic therapy. OP patients were 87.9% male, median age 58, 96.3% HPV+, with median follow up of 60.8 months. Smoking status was 20.9% current, 44.5% former, 34.6% never, with 20 median pack years. Disease was 67.9% T1-2, 32.1% T3-4, 29.9% N0-2a, 70.1% N2b-3. 11.5% had surgery & 87.3% had concurrent systemic therapy. Specifically, 52.2% of OP patients received concurrent cisplatin, 10.6% concurrent cetuximab, and 24.5% other systemic therapies. 11.7% of patients experienced DF, of which 77% failed in the lung. Within the OC cohort, nodal stage 2b or higher was the only predictive factor (HR 3.26, p < 0.001), conferring a 3 year risk of DF of 34% vs 10%. Within the OP cohort, a high risk cohort of 87 patients (12.9%) was identified with a 3 year incidence DF of 22%, compared to 10% or less in lower risk cohorts. This high risk cohort consisted of active smokers treated with definitive RT and either concurrent cisplatin or no concurrent therapy, with at least T3 and N2b disease, as well as any patients treated with definitive RT and concurrent cetuximab. Conclusions: We identified groups of OC & OP patients with greater than 20% risk of developing DF at 3 years, the majority of which occurred in the lung. Surveillance imaging of the chest should be considered for patients meeting these criteria.

SAT-398 The Use of Imaging in Primary Hyperparathyroidism

Primary hyperparathyroidism is characterized by excessive dysregulated production of parathyroid hormone (PTH) by 1 or more abnormal parathyroid glands. Preoperative localization is important for surgical planning in primary hyperparathyroidism. Previously, it had been published that ultrasound (sensitivity of 76.1%, positive predictive value of 93.2%) and nuclear scintigraphy (Sestamibi-SPECT) (sensitivity of 78.9%, and a positive predictive value of 90.7%) are first line imaging modalities1. Currently, the imaging modality of choice varies according to region and institutional protocol. The aim of this study was to evaluate the imaging modality that is associated with an improved remission rate based on concordance with operative findings. A secondary aim was to determine the effect of additive imaging on remission rates. This was an IRB-approved retrospective review of 2657 patients with primary hyperparathyroidism undergoing surgery at a tertiary referral center from 2004–2017. Analyses were performed with SAS software using a 95% confidence interval (p&lt;0.05) for statistical significance. After excluding re-operative and familial cases, 2079 patients met study criteria. There were 422 (20.3%) male and 1657 (79.7%) female patients with a mean age of 66 (+12.2) years, of which 1723 (82.9%) of patients were white and 294 (14.1%) patients were black. Ultrasound (US) was performed in 1891 (91.9%), sestamibi with SPECT (sestamibi/SPECT) in 1945 (93.6%), and CT in 98 (4.7%) patients. Of these, 1721 (82.8%) had combined US and sestamibi/SPECT. US was surgeon-performed in 94.2% of cases and 89.9% of the patients underwent a four gland exploration. Overall, US concordance was 52.4%, sestamibi/SPECT was 45.5%, and CT was 45.9%.US and sestamibi/SPECT both had an improved remission rate if concordant with operative findings, while CT had no effect (US p=0.04; sestamibi/SPECT p=0.01; CT p=0.50). The overall remission rate was 94% (CI=0.93–0.95), however, increasing the number of imaging modalities performed did not increase the remission rate (p=0.76) or concordance with operative findings (p=0.05). Despite having low concordance rates, US and sestamibi/SPECT that agreed with operative findings were associated with higher remission rates. Therefore, when imaging is to be used for localization, our data support the use of US and sestamibi/SPECT as the initial imaging modalities of choice for preoperative localization.

1Kuzminski SJ, Sosa JA, Hoang JK. Update in Parathyroid Imaging. Magn Reson Imaging Clin N Am. 2018;26(1): 151–166.

Tumor Volume Useful Beyond Classic Criteria in Selecting Larynx Cancers For Preservation Therapy

OBJECTIVE

To investigate the association between tumor volume and locoregional failure (LRF) after concurrent chemoradiation (CCRT) for locally advanced larynx cancer (LC).

METHODS

This is a retrospective cohort study from 2009 to 2014 identified from an institutional review board-approved registry. Fifty-nine of 68 patients with locally advanced larynx cancer treated with definitive CCRT who had available imaging for review were identified. The main endpoint to be assessed was the association between gross tumor volumes (GTV; T = total, P = primary, N = nodal) and LRF. Receiver operative characteristic (ROC) curves were used to investigate diagnostic accuracy.

RESULTS

Twenty LRFs were observed, resulting in a 2-year LRF rate of 39% (95% CI, 23-52%). On UVA, the GTV-T (P = .01), GTV-P (P = .05), and GTV-N (P = .04) were statistically significant predictors of LRF. Furthermore, age, smoking status, N-stage, larynx subsite, and tracheostomy/feeding tube dependence were potentially associated with LRF (P < .3), whereas T-stage (T3-4 vs. T2) was not (HR 1.05, 95% CI, 0.38-2.91, P = .92). In the multivariable model, GTV-P (HR 1.022, 95% CI, 0.999-1.046, P = .07) and GTV-N (HR 1.053, 95% CI, 1.0004-1.108, P = .05) were the two most impactful covariates on the model's R² . ROC analysis suggested an optimal cut point of 12 cc in the GTV-T. The 2-year LRF for GTV-T > 12 cc was 64.2% and ≤ 12 cc was 16.4%, P = .006.

CONCLUSION

GTV is associated with LRF after definitive CCRT for LC. Patients with bulky primary and/or nodal tumors may be better served with upfront surgical resection regardless of T-stage. Further investigation into the safety of larynx preservation for low-volume T4 tumors can be considered.

LEVEL OF EVIDENCE

4 Laryngoscope, 130:2372-2377, 2020.

Outcomes of post-operative treatment with concurrent systemic therapy and radiotherapy (RT) in intermediate (INT) risk resected oral cavity squamous cell carcinoma (OCSCC): A multi-institutional collaboration

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Background: Patients (pts) with adverse pathologic factors in resected OCSCC excluding positive surgical margins or extranodal extension represent a group of INT risk disease. Though not standard of care, adjuvant CRT is often used in INT pts. We conducted a multi-institutional study to evaluate factors associated with improved outcomes in INT pts treated with or without chemotherapy. Methods: An IRB-approved collaborative database of patients with primary OCSCC (Stage I-IVB AJCC 7th edition) treated with primary surgical resection between 1/1/2005 and 1/1/2015 with or without adjuvant therapy was established from 6 academic institutions. Pts were categorized by pathologic features and adjuvant therapy. Kaplan Meier curves, log-rank p-values and multivariate analysis (MVA) were used to describe outcomes by treatment including locoregional control (LRC) and disease free survival (DFS). Results: From a total sample size of 1270 patients, 455 INT risk pts were treated with primary surgical resection and adjuvant therapy; 95 received CRT, 274 received RT alone, and 86 received RT without recorded chemotherapy. 49% of pts had perineural invasion (PNI), 24.8% lymphovascular space invasion, 21.5% poorly differentiated histology, 47.3% with pT3/4 disease, and 27.9% with > 2 lymph node positive (LN+). 55.8% of CRT pts were treated with cisplatin. > 2 LN+ was the only significant predictor of LRC (HR 1.49, p= 0.049). PNI and > 2 LN+ were significant predictors of DFS (HR 1.52, p= 0.003 and HR 1.76, p< 0.001). On MVA, after adjusting for > 2 LN+, treatment with cisplatin-RT was borderline significant for LRC (HR 0.52, p= 0.08). 3 year LRC in pts with > 2 LN+ was 84.4% in pts treated with cisplatin-RT compared with 64.9% for RT alone. Conclusions: The addition of cisplatin-based CRT to INT risk pts is controversial but among pts with > 2 LN+ there was a trend toward benefit. This study is limited by small numbers of pts treated with CRT, though these results highlight the need for further investigation in this population to identify INT pts who would benefit from adjuvant therapy intensification.

Factors associated with recurrence and death in patients with aggressive hobnail morphology papillary thyroid carcinoma

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Background: Papillary thyroid carcinoma (PTC) with hobnail morphology (HM) is an aggressive variant associated with poorer outcomes compared to classical PTC, with a little over 100 cases reported in the literature. We aim to identify prognostic factors potentially associated with recurrence and death in the largest single institutional experience of PTC with HM. Methods: From an IRB approved registry, we identified all PTC HM cases with patient, diagnostic and treatment data and outcomes. Hobnail variant (HV) PTC had ≥30% HM; pure hobnail features (PHF) had < 30% HM without tall cell morphology (TCM) & multi variant features (MVF) had both HM & TCM. Demographic and clinical features at time of HM diagnosis that were potentially associated with 3-yr event free (death or recurrence) survival (EFS) were evaluated using Kaplan-Meir method (KM). Results: Forty-five (median age 55 yo, range 19-86 yo; 66.7% female) HM pts (35 HM at initial PTC, 10 at recurrence) were evaluable. Majority were ECOG 0 (84.1%). HM: 44.4% MVF, 37.8% PHF, & 17.8% HV; 68.9% pT3/T4; 64.4% node positive; & 15.6% metastatic. Positive surgical margins (+SM) with HM in 31.8%. RAI at HM given to 73%. Overall EFS was 83.5% at 1-yr & 69.6% at 2-yr. Of 13 events at 3 yrs, 4 were deaths (3 from PTC) & 9 recurrences. All events were in those > 55 yo (p < 0.001) with pT3/T4 disease (p = 0.01). Non-0 ECOG (KM 2-yr EFS: 28.6% vs 77.7%, p = 0.002), cT3/T4 (49.5% vs 85.5%p = 0.004), and +SM (32.1% vs 92.1%, p = 0.001) were also associated with EFS compared to their counterpart. HM grouping, RAI, initial HM vs HM at recurrence, sex, and tumor size were not statistically significant. Conclusions: To our knowledge, this is the largest reported cohort of PTC with HM. We identified several factors potentially associated with recurrence and death. There was no difference in outcomes between HV versus PHF versus MVF, which raises question to validity of 30% cutoff in defining “variant” versus “features of variant”. Age > 55 yo, T3/T4 disease, and +SM exhibited significantly inferior EFS. Further evaluation in a multi-institutional cohort will help in validating these findings and help identify patients who warrant more aggressive initial treatment.

Preliminary safety results of a phase II study investigating pembrolizumab in combination with postoperative intensity modulated radiotherapy (IMRT) in resected high risk cutaneous squamous cell cancer of the head and neck

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Background: High risk cutaneous squamous cell cancer of the head and neck (cSCC-HN) have suboptimal outcomes with surgery and postoperative radiation. We report preliminary safety outcomes of a phase II study (NCT03057613) exploring the safety and efficacy of the addition of Pembrolizumab to postoperative IMRT. Methods: Patients with cSCC-HN were eligible for this IRB approved study if they had resection of all gross disease and demonstrated (a) invasion of the skeleton or skull base; (b) node positive disease; (c) or a tumor > 2cm with ≥1 of the following risk factors: recurrent disease, perineural invasion, lymphovascular space invasion, poorly differentiated, positive margins, satellitosis or in-transit metastases. Immune competent pts and those with CLL were eligible. This study aimed to accrue 34 evaluable patients to assess a primary safety endpoint of dose limiting toxicity (DLT) defined as any grade ≥3 toxicity at least possibly related to the immunotherapy. Assuming toxicity of < 20% is acceptable and > 40% is unacceptable, if ≥11 of 34 (32%) patients experienced a DLT, the regimen would be considered unsafe. Results: Of 15 pts already enrolled on this study, 11 have completed the protocol treatment. There were no DLTs observed to date. Grade 2 immune related toxicity was seen in two patients, one with bullous pemphigoid and another with lymphopenia and peripheral neuropathy and weakness in his hands in the setting of a prior cervical spine injury. Both responded to steroids and recovered completely. Based on this initial cohort, the 95% confidence intervals (CI) on DLTs for the entire cohort is 0-28%. Using the most conservative CI of 28%, the likelihood of 11 of the remaining 23 patients experiencing a DLT is 3.4%. Assuming a CI of 20%, the risk is 0.3%. None of the 11 pts who have completed protocol therapy have experienced a recurrence. Conclusions: The addition of Pembrolizumab to postoperative IMRT in high risk cSCC-HN is safe and will be studied in a randomized phase III adjuvant study (Keynote 630). This phase II study will continue to enroll CLL patients to assess safety and efficacy signals in this unique higher risk population. Clinical trial information: NCT03057613.

Incidence of severe late toxicities of head and neck squamous cell cancer (HNSCC) treatment in the era of intensity modulated radiotherapy (IMRT)

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Background: IMRT for HNSCC limits exposure to critical nearby structures thereby reducing toxicities. Real world data on toxicities after long term follow-up post IMRT for HNSCC are lacking. This study assessed the incidence of late toxicities in patients with HNSCC within 5 years post-treatment with definitive IMRT (d-IMRT). Methods: This is a retrospective, IRB approved, single-institution review of patients (pts) with stage I-IVB HNSCC treated with d-IMRT +/- chemotherapy between 2009 and 2013. The primary outcomes were incidence of severe late toxicities (dysphagia requiring esophageal stricture dilation, physician-reported grade 2 or worse neck fibrosis and xerostomia) occurring 3 months or more after completion of IMRT; feeding tube (FT) dependence within 1st year of IMRT completion, and FT dependence beyond 1st year post IMRT. Toxicities were deemed acute if they occurred during IMRT and up to 90 days post IMRT. Results: 274 pts, median age 59 years (38 – 82.9), were identified. 67.6% were HPV positive, 10.5% HPV negative and HPV status was unknown in 21.9%. Site of disease was oropharynx in 70%, larynx in 25% and hypopharynx in 4%. 206 pts (75.2%) received d-IMRT alone, 37 (13.5%) had definitive concurrent chemoradiation – mostly with cisplatin (58%), and 31 (11.3%) received adjuvant IMRT. Of the 243 pts treated with d-IMRT +/- chemotherapy, 80 (32.9%) required FT during RT due to grade 2 or worse acute dysphagia. Excluding 11 pts with disease recurrence or new HNSCC diagnosis, FT dependence at any time from 3 months to one year post IMRT occurred in 22 of 232 pts (9.48%), while FT dependence beyond 1st year post IMRT occurred in 8 pts (3.4%). 11 pts (4.7%) required stricture dilation for late dysphagia. Late grade 2 or worse fibrosis and xerostomia occurred in 7 (3.0%) and 89 (38.4%) pts, respectively. Conclusions: Our study suggests that except for xerostomia, severe late toxicities after definitive IMRT for HNSCC is likely uncommon. Prospective studies with late IMRT toxicities and their impact on quality of life (QoL) as endpoints are warranted.