The transcription factor encyclopedia

Here we present the Transcription Factor Encyclopedia (TFe), a new web-based compendium of mini review articles on transcription factors (TFs) that is founded on the principles of open access and collaboration. Our consortium of over 100 researchers has collectively contributed over 130 mini review articles on pertinent human, mouse and rat TFs. Notable features of the TFe website include a high-quality PDF generator and web API for programmatic data retrieval. TFe aims to rapidly educate scientists about the TFs they encounter through the delivery of succinct summaries written and vetted by experts in the field. TFe is available at http://www.cisreg.ca/tfe.

A validated quantitative assay to detect occult micrometastases by reverse transcriptase-polymerase chain reaction of guanylyl cyclase C in patients with colorectal cancer

PURPOSE

Guanylyl cyclase C (GCC), a receptor for bacterial diarrheagenic enterotoxins, may be a prognostic and predictive marker to detect occult micrometastases in patients undergoing staging for colorectal cancer. However, quantification of GCC expression in tissues by the quantitative reverse transcription-PCR (qRT-PCR) has not undergone analytic and clinicopathologic validation.

EXPERIMENTAL DESIGN

A technique to quantify GCC mRNA in tissues employing RT-PCR was developed and validated employing external calibration standards of RNA complementary to GCC.

RESULTS

GCC qRT-PCR exhibited reaction efficiencies >92%, coefficients of variations <5%, linearity >6 orders of magnitude, and a limit of quantification of >25 copies of GCC cRNA. This assay confirmed that GCC mRNA was overexpressed by colorectal tumors from 41 patients, which correlated with increased GCC protein quantified by immunohistochemistry. Analyses obtained with 164 lymph nodes from patients free of cancer and 15 nodes harboring metastases established a threshold for metastatic disease of approximately 200 GCC mRNA copies/mug total RNA, with a sensitivity of 93% and specificity of 97%. GCC mRNA above that threshold was detected in 76 of 367 (approximately 21%) nodes free of disease by histopathology from 6 of 23 (26%) patients, suggesting the presence of occult micrometastases.

CONCLUSIONS

Quantifying GCC mRNA in tissues by RT-PCR employing external calibration standards is analytically robust and reproducible, with high clinicopathologic sensitivity and specificity. This validated assay is being applied to approximately 10,000 lymph nodes in a prospective trial to define the sensitivity of GCC qRT-PCR for staging patients with colorectal cancer.

The putative tumor suppressor Cdx2 is overexpressed by human colorectal adenocarcinomas

PURPOSE

The current paradigm suggests that the homeodomain transcription factor Cdx2, which directs the development and maintenance of the intestinal epithelium, is a tumor suppressor in the colon and rectum. Although a cardinal property of tumor suppressors is their inactivation during carcinogenesis, the expression of Cdx2 in colorectal tumors has not been compared with that in normal mucosa. Here, Cdx2 expression and function was quantified in tumors and matched normal mucosa from patients with colorectal cancer.

EXPERIMENTAL DESIGN

Cdx2 expression was quantified by reverse transcription-PCR, immunoblot analysis, and immunohistochemistry. Transcriptional activity was explored by quantifying expression of an endogenous downstream target of Cdx2, guanylyl cyclase C (GCC), in tissues by quantitative reverse transcription-PCR and expression of exogenous Cdx2-specific luciferase promoter constructs in epithelial cells isolated from tumors and normal mucosa.

RESULTS

Most (>80%) colorectal tumors overexpressed Cdx2 mRNA and protein compared with normal mucosa, with median fold increases of 3.6 and 1.4, respectively (P<0.002). Concomitantly, immunohistochemistry revealed elevated levels of Cdx2 in nuclei of tumor cells compared with normal epithelial cells. Further, tumors exhibited increased expression of GCC compared with normal mucosa. Moreover, cells isolated from tumors overexpressed a Cdx2-specific luciferase promoter construct compared with normal mucosal cells.

CONCLUSION

These observations show, for the first time, the structural and functional overexpression of Cdx2 by human colorectal tumors compared with matched normal mucosa. They suggest that loss of Cdx2 expression or transcriptional activity is an infrequent event during tumorigenesis, which does not contribute to molecular mechanisms underlying initiation and progression of most colorectal tumors.

Small cell carcinoma of the head and neck: An analysis of the National Cancer Database

PURPOSE/OBJECTIVE(S)

To evaluate treatment trends and overall survival of patients with small cell carcinoma of the head and neck region.

MATERIALS/METHODS

Patients from 2004 to 2012 were identified from the National Cancer Database. Patient demographics and overall survival were analyzed. Multivariable analysis was used to identify predictors of survival.

RESULTS

Among 347,252 head and neck patients a total of 1042 (0.3%) patients with small cell carcinoma were identified. 17% of patients were diagnosed as stage I/II, 61% as stage III/IVA/IVB and 22% as stage IVC disease. The distribution by anatomic site was 9% oral cavity, 12% oropharynx, 35% larynx, 4% hypopharynx, 10% nasopharynx and 30% nasal cavity and paranasal sinuses. The median overall survival by anatomical site was 20.8months for oral cavity, 23.7months for oropharynx, 17.9months for larynx/hypopharynx, 15.1months for nasopharynx and 36.4months for nasal cavity primary tumors. On multivariable analysis across stage, patients with nasal cavity and paranasal sinuses tumors had the best survival and patients with nasopharynx primaries had the worst survival. In stage I/II patients, type of treatment delivered resulted in no overall survival difference (p=0.78). In patients with locally advanced disease, there was no difference in survival between those treated with combined surgery, radiotherapy and chemotherapy compared to those treated only with radiotherapy and chemotherapy (p=0.46). The addition of radiotherapy to chemotherapy in the metastatic setting did not result in improved survival (p=0.14).

CONCLUSIONS

Small cell carcinoma of the head and neck is a rare malignancy with a poor prognosis. The addition of surgery to radiotherapy and chemotherapy did not improve survival in patients with locally advanced disease.

Improved survival with dose-escalated radiotherapy in stage III non-small-cell lung cancer: analysis of the National Cancer Database

BACKGROUND

Concurrent chemoradiation is the standard of care in non-operable stage III non-small-cell lung cancer (NSCLC). Data have suggested a benefit of dose escalation; however, results from the randomized dose-escalation trial RTOG 0617 revealed a lower survival rate with high-dose radiation. To evaluate the impact of dose escalation on overall survival (OS) in stage III NSCLC treated with chemoradiotherapy outside the controlled setting of a randomized trial, we carried out an observational, population-based investigation of the National Cancer Database (NCDB).

PATIENTS AND METHODS

A total of 33 566 patients with stage III NSCLC treated with chemoradiation from 2004 to 2012 and radiation doses between 59.4 and 85 Gy were included. The primary end point was OS, with median survival calculated via Kaplan-Meier. Univariate, multivariable and propensity-score matching analyses were carried out.

RESULTS

Patients were stratified by dose with median OS of: 18.8, 19.8 and 21.6 months for cohorts receiving 59.4-60, 61-69 and ≥70 Gy, respectively (P < 0.001). Granular dose analyses were carried out demonstrating increased OS with increasing radiation dose: median survival of 18.8, 21.1, 22.0 and 21.0 months for 59.4-60, 66, 70 and ≥71 Gy, respectively. While 66, 70 and ≥71 Gy resulted in increased OS in comparison with 59.4-60 Gy, no significant difference in OS was observed when comparing 66 with ≥71 Gy (P = 0.38).

CONCLUSIONS

Dose escalation above 60 Gy was associated with improved OS in this cohort of stage III NSCLC patients treated with chemoradiotherapy. A plateau of benefit was observed, with no additional improvement in OS with increased dose (≥71 Gy) compared with 66-70 Gy. With evidence suggesting worse OS and quality of life with increased dose, these data support investigation of the role of intermediate-dose radiation, and in the absence of randomized evidence, may be leveraged to justify utilization of intermediate-dose radiation.

Prognostic implications of human papillomavirus status for patients with non-oropharyngeal head and neck squamous cell carcinomas

PURPOSE

We examined overall survival in a large cohort of patients with human papillomavirus (HPV)-positive and HPV-negative non-oropharyngeal squamous cell carcinoma of the head and neck (non-OPSCC).

METHODS

Patients diagnosed with non-OPSCC and known HPV status were identified in the National Cancer Database (NCDB). Multivariate logistic regression was applied to examine factors associated with HPV status. Multivariate analysis was utilized to determine factors correlated with overall survival. Propensity score-weighted Kaplan-Meier estimation was used to adjust for confounders in survival analyses. Multiple imputation method was used for sensitivity analysis.

RESULTS

We identified 19,993 non-OPSCC patients with 5070 being positive for HPV in the NCDB. Median follow-up was 23.5 months. HPV-positive patients were more commonly male, white, with a lower comorbidity index score, presenting with T-stage <2, and N-stage ≥1. Unadjusted 3-year overall survival was 62% and 80% for HPV-negative and HPV-positive patients, respectively (p < 0.0001). On multivariate analysis, mortality was reduced for HPV-positive patients with early stage (HR = 0.68) and locally advanced disease (HR = 0.46). Adjusted 3-year overall survival was 65% for HPV-negative and 76% for HPV-positive patients (p < 0.0001). The survival advantage of HPV was maintained in all subsites and robust on sensitivity analysis.

CONCLUSIONS

Patients with HPV-positive non-OPSCC exhibit similar characteristics as HPV-positive OPSCC. Overall survival was significantly higher for patients with HPV-positive versus HPV-negative non-OPSCC. These data reveal that HPV-positive non-OPSCC represent a favorable cohort that warrants recognition in the design of future clinical trial investigation.

Survival Outcomes for Patients With T3N0M0 Squamous Cell Carcinoma of the Glottic Larynx

Importance

Radiotherapy (RT)-based organ preservation approaches for patients with advanced laryngeal cancer have been established stepwise through prospective randomized clinical trials. However, broad adoption of these approaches has stimulated discussion about long-term results challenging their applicability in a heterogeneous patient population, most recently for patients with T3 disease.

Objective

To define outcomes in patients with clinical T3N0M0 glottic laryngeal cancer treated with definitive surgical and RT-based approaches.

Design, Setting, and Participants

This retrospective cohort study included patients treated from January 1, 2004, through December 31, 2013, with a median follow-up time of 58 months (range, 0-126.6 months) in the National Cancer Database. Of the 4003 patients with T3N0M0 disease, 2622 received definitive therapy defined by the study protocol. Data were obtained from the clinical oncology database sourced from hospital registry data that are collected from more than 1500 Commission on Cancer-accredited facilities. Data were analyzed from September 14, 2016, through April 24, 2017.

Interventions

Radiotherapy, chemoradiotherapy, surgery, surgery and RT, or surgery and chemoradiotherapy.

Main Outcomes and Measures

Five-year overall survival (OS).

Results

A total of 2622 patients (2251 men [85.9%] and 371 women [14.1%]; median age, 64 years [range, 19-90 years]) were included in the analytic cohort. In the overall patient cohort, the adjusted 5-year survival probability was 53%. No statistical differences were observed between the primary surgery (53%; 95% CI, 48%-57%) and primary RT (54%; 95% CI, 52%-57%) cohorts. In multivariate analysis, patient factors associated with decreased OS included age (hazard ratio [HR], 1.04; 95% CI, 1.03-1.04), insurance status (HR, 1.26; 95% CI, 1.06-1.50), and increasing comorbidity (HR, 1.20; 95% CI, 1.02-1.42).

Conclusions and Relevance

Current management of T3N0M0 glottic laryngeal cancer relies largely on RT-based organ preservation approaches. The present study substantiates randomized clinical trial data supporting the use of RT-based organ preservation approaches for patients with T3N0M0 glottic laryngeal cancer without compromising OS.

Clinical outcomes for patients presenting with N3 head and neck squamous cell carcinoma: Analysis of the National Cancer Database

BACKGROUND

There is a paucity of data regarding head and neck squamous cell carcinomas (HNSCCs) and N3 nodal disease.

METHODS

Retrospective analysis of patients with N3 HNSCC identified in the National Cancer Database (NCDB) was performed.

RESULTS

We identified 4867 patients with N3 HNSCC treated with primary surgery or chemoradiotherapy (CRT). Propensity-adjusted median survival was 54.2 and 44.8 months for surgery and CRT, respectively (P = .06). Oropharyngeal primary subsite demonstrated a survival advantage with surgery versus CRT with propensity-adjusted median survivals of 86.0 and 61.9 months, respectively (P < .05).

CONCLUSION

Management of N3 HNSCC relies largely on CRT. Patients with N3 nodal disease with nonoropharyngeal primary tumors exhibit 5-year overall survival approaching 30% independent of initial treatment modality. Patients with oropharyngeal primaries exhibit improved outcomes with surgery largely influenced by the human papillomavirus (HPV)-negative subset. These data represent the most comprehensive analysis of N3 HNSCC outcomes and serves as a foundation for future research and clinical management.

Impact of HPV Status on the Prognostic Potential of the AJCC Staging System for Larynx Cancer

Objective We evaluated the ability of the American Joint Committee on Cancer (AJCC) seventh edition staging system to prognosticate the overall survival of patients with human papillomavirus (HPV)-positive laryngeal squamous cell carcinoma. Study Design Retrospective analysis. Setting National Cancer Database. Subjects and Methods Patients diagnosed with laryngeal squamous cell carcinoma who were treated with curative intent were identified in the National Cancer Database. Multivariate analysis was utilized to determine factors correlated with overall survival in the HPV-negative and HPV-positive cohorts. Unadjusted and propensity score-weighted Kaplan-Meier estimation was used to determine overall survival of HPV-negative and HPV-positive patients across AJCC stage groupings. Results We identified 3238 patients with laryngeal squamous cell carcinoma, of which 2812 were HPV negative and 426 were HPV positive. Overall survival adjusted for age, sex, and comorbidity status confirmed significant differences among all consecutive stage groupings (I vs II, P < .001; II vs III, P < .05; III vs IVA, P < .001; IVA vs IVB, P < .05) in the HPV-negative cohort, whereas only stages IVAs and IVB ( P < .01) exhibited a significant difference in overall survival for HPV-positive patients. Conclusion The current AJCC staging system does not accurately distinguish risk of mortality for patients with HPV-positive disease. These data support the consideration of HPV status in estimating prognosis as well as clinical trial design and clinical decision making for patients with laryngeal squamous cell carcinoma.

HPV impacts survival of stage IVC non-oropharyngeal HNSCC cancer patients

Objectives

Human papillomavirus (HPV) status is a favorable prognostic marker for patients with oropharyngeal squamous cell carcinoma (OPSCC) and non-metastatic head and neck non-OPSCC. We evaluated the impact of HPV status on overall survival (OS) for patients with Stage IVC non-OPSCC.

Materials and methods

Patients diagnosed with Stage IVC non-OPSCC and known HPV status between 2010-2013 were identified in the National Cancer Database. Univariate and multivariate analyses were performed to determine factors associated with OS. Propensity score-weighted Kaplan-Meier estimation was used to adjust for confounders in OS analyses. Multiple imputation method was used for sensitivity analysis.

Results

We identified 708 patients with Stage IVC non-OPSCC with 30% being HPV-positive. Unadjusted median survival was 10.3 months for HPV-negative patients and 21.4 months for HPV-positive patients (p<0.0001). Age ≥ 65 and tumor diameter were associated with worse OS (p<0.05) while treatment versus no treatment and HPV-positive status were associated with improved OS on multivariate analysis (p<0.001). Adjusted median survival for patients with HPV-negative and HPV-positive disease was 11.1 months and 23.8 months, respectively (p<0.001). On unadjusted subgroup analysis, patients with HPV-positive oral cavity disease exhibited improved outcomes (p<0.0001) while HPV-positive hypopharynx (p<0.06) and larynx (p<0.12) patients exhibited a trend for improved OS compared to HPV-negative patients. The survival advantage associated with HPV positivity was maintained on sensitivity analysis (p<0.01).

Conclusion

These data demonstrate a clinically meaningful association between HPV status and OS in patients with non-OSPCC presenting with Stage IVC disease. In the absence of randomized data, these findings support active consideration of HPV status in clinical decision making, clinical trial design, and patient counseling regarding prognosis.

Clinical outcomes for larynx patients with cancer treated with refinement of high-dose radiation treatment volumes

BACKGROUND

To evaluate disease control, toxicities, and dose to dysphagia/aspiration risk structures (DARS) using a direct gross tumor volume (GTV_70Gy ) to planning target volume expansion (dPTV_70Gy ) for patients with squamous cell carcinoma of the larynx (LSCC).

METHODS

A retrospective review was performed on patients with LSCC treated between 2003 and 2018. Clinical outcomes, toxicities, and dosimetric data were analyzed.

RESULTS

Seventy-three patients were identified. Overall survival at 5-years was 57.8%. Five-year local and regional control was 79.8% and 88.2%, respectively. Distant metastatic-only failure was 2.7%. Eighty percent of failures were 95% contained within the dPTV_70Gy . Mean dose and the volume of DARS receiving 70 Gy was significantly lower for dPTV_70Gy compared to a consensus-defined PTV_70Gy .

DISCUSSION

Judicious reduction in high-dose target volumes can preserve high tumor control rates while reducing dose to normal surrounding structures underscoring the potential benefit of this approach in enabling local therapy intensification to improve locoregional control.

A novel CDX2 isoform regulates alternative splicing

Gene expression is a dynamic and coordinated process coupling transcription with pre-mRNA processing. This regulation enables tissue-specific transcription factors to induce expression of specific transcripts that are subsequently amplified by alternative splicing allowing for increased proteome complexity and functional diversity. The intestine-specific transcription factor CDX2 regulates development and maintenance of the intestinal epithelium by inducing expression of genes characteristic of the mature enterocyte phenotype. Here, sequence analysis of CDX2 mRNA from colonic mucosa-derived tissues revealed an alternatively spliced transcript (CDX2/AS) that encodes a protein with a truncated homeodomain and a novel carboxy-terminal domain enriched in serine and arginine residues (RS domain). CDX2 and CDX2/AS exhibited distinct nuclear expression patterns with minimal areas of co-localization. CDX2/AS did not activate the CDX2-dependent promoter of guanylyl cyclase C nor inhibit transcriptional activity of CDX2. Unlike CDX2, CDX2/AS co-localized with the putative splicing factors ASF/SF2 and SC35. CDX2/AS altered splicing patterns of CD44v5 and Tra2-β1 minigenes in Lovo colon cancer cells independent of CDX2 expression. These data demonstrate unique dual functions of the CDX2 gene enabling it to regulate gene expression through both transcription (CDX2) and pre-mRNA processing (CDX2/AS).

Pancreatic cancer planning: Complex conformal vs modulated therapies

To compare the roles of intensity-modulated radiation therapy (IMRT) and volumetric- modulated arc therapy (VMAT) therapy as compared to simple and complex 3-dimensional chemoradiotherpy (3DCRT) planning for resectable and borderline resectable pancreatic cancer. In all, 12 patients who received postoperative radiotherapy (8) or neoadjuvant concurrent chemoradiotherapy (4) were evaluated retrospectively. Radiotherapy planning was performed for 4 treatment techniques: simple 4-field box, complex 5-field 3DCRT, 5 to 6-field IMRT, and single-arc VMAT. All volumes were approved by a single observer in accordance with Radiation Therapy Oncology Group (RTOG) Pancreas Contouring Atlas. Plans included tumor/tumor bed and regional lymph nodes to 45Gy; with tumor/tumor bed boosted to 50.4Gy, at least 95% of planning target volume (PTV) received the prescription dose. Dose-volume histograms (DVH) for multiple end points, treatment planning, and delivery time were assessed. Complex 3DCRT, IMRT, and VMAT plans significantly (p < 0.05) decreased mean kidney dose, mean liver dose, liver (V30, V35), stomach (D10%), stomach (V45), mean right kidney dose, and right kidney (V15) as compared with the simple 4-field plans that are most commonly reported in the literature. IMRT plans resulted in decreased mean liver dose, liver (V35), and left kidney (V15, V18, V20). VMAT plans decreased small bowel (D10%, D15%), small bowel (V35, V45), stomach (D10%, D15%), stomach (V35, V45), mean liver dose, liver (V35), left kidney (V15, V18, V20), and right kidney (V18, V20). VMAT plans significantly decreased small bowel (D10%, D15%), left kidney (V20), and stomach (V45) as compared with IMRT plans. Treatment planning and delivery times were most efficient for simple 4-field box and VMAT. Excluding patient setup and imaging, average treatment delivery was within 10minutes for simple and complex 3DCRT, IMRT, and VMAT treatments. This article shows significant improvements in 3D plan performance with complex planning over the more frequently compared 3- or 4-field simple 3D planning techniques. VMAT plans continue to demonstrate potential for the most organ sparing. However, further studies are required to identify if dosimetric benefits associated with inverse optimized planning can be translated into clinical benefits and if these treatment techniques are value-added therapies for this group of patients with cancer.

Defining high-risk elective contralateral neck radiation volumes for oropharynx cancer

BACKGROUND

To define the location of the initial contralateral lymph node (LN) metastasis in patients with oropharynx cancer.

METHODS

The location of the LN centroids from patients with oropharynx cancer and a single radiographically positive contralateral LN was defined. A clinical target volume (CTV) inclusive of all LN centroids was created, and its impact on dose to organs at risk was assessed.

RESULTS

We identified 55 patients of which 49/55 had a single contralateral LN in level IIA, 4/55 in level III, 1/55 in level IIB, and 1/55 in the retropharynx. Mean radiation dose to the contralateral parotid gland was 15.1 and 21.0 Gy, (p <0.001) using the modeled high-risk elective CTV and a consensus CTV, respectively.

CONCLUSIONS

We present a systematic approach for identifying the contralateral nodal regions at highest risk of harboring subclinical disease in patients with oropharynx cancer that warrants prospective clinical study.

Abstract B30: Locoregional control in laryngeal and hypopharyngeal cancer patients treated with radiotherapy using direct gross tumor volume to planning target volume expansion

Purposes/Objectives(s): To evaluate clinical outcomes and patterns of failure using a direct gross tumor volume to planning target volume expansion in patients treated for laryngeal or hypopharyngeal squamous cell carcinomas.

Methods and Materials: We performed a retrospective review of patients with laryngeal or hypopharyngeal squamous cell carcinomas treated between 2002-2017 with primary radiotherapy with or without concurrent systemic therapy. Patient and disease characteristics associated with disease control and clinical outcomes were analyzed by Cox proportional hazards regression and Kaplan-Meier analyses. Deformable image registration between imaging at the time of failure and the treatment planning scan was used to determine patterns of failure.

Results: Seventy-nine patients with laryngeal or hypopharyngeal squamous cell carcinoma were identified with a median follow-up of 54 months among surviving patients. Overall survival at 5 years was 62.9% (95% CI: 51.1%-74.7%). Five-year primary tumor control was 71.6% (95% CI: 61.4%-81.8%) and regional control was 78.8% (95% CI: 68.4%-89.2%). A total of 28 patients experienced a locoregional recurrence, of whom 18 had treatment plans available. Of these, 89% (n=16) experienced failures that were 95% contained within the high-dose treatment volume. One patient failed in an intermediate-dose volume and 1 exhibited a marginal failure in the high-dose volume. There were no factors associated with overall survival or locoregional control on multivariate analysis.

Conclusion: Management of patients with laryngeal or hypopharyngeal squamous cell carcinoma using definitive radiotherapy and a high-dose planning target volume created without a gross tumor volume to clinical tumor volume expansion resulted in high locoregional control, with the vast majority of failures occurring within the high-dose field. These data support prospective evaluation of this technique.

Citation Format: Adam R. Burr, Paul M. Harari, Matthew E. Witek. Locoregional control in laryngeal and hypopharyngeal cancer patients treated with radiotherapy using direct gross tumor volume to planning target volume expansion [abstract]. In: Proceedings of the AACR-AHNS Head and Neck Cancer Conference: Optimizing Survival and Quality of Life through Basic, Clinical, and Translational Research; 2019 Apr 29-30; Austin, TX. Philadelphia (PA): AACR; Clin Cancer Res 2020;26(12_Suppl_2):Abstract nr B30.

Opioid use in patients undergoing treatment for oral cavity cancer

OBJECTIVE

In the context of the opioid epidemic, there is value in examining the use of opioids in specific cancer patient cohorts. We analyzed opioid use in patients undergoing adjuvant therapy for oral cavity cancer to define the incidence of new persistent use beyond 3 months.

STUDY DESIGN

Retrospective.

SETTING

Comprehensive academic cancer center.

SUBJECTS AND METHODS

We performed a retrospective IRB-approved analysis of opioid use in patients who received adjuvant radiotherapy with or with concurrent systemic therapy for surgically resected oral cavity cancer between 2003 and 2016. Factors associated with opioid use were evaluated by Chi-square test and one-way ANOVA. The Kaplan-Meier method was used to estimate overall survival.

RESULTS

Of 77 identified patients, 10 (13%) patients received opioid prescriptions at 3 months or greater following completion of radiotherapy. Patients who were opioid naive prior to surgery required significantly fewer opioid prescriptions than intermittent or chronic opioid users. No specific factors were associated with new persistent opioid use.

CONCLUSIONS

Patients undergoing surgery and adjuvant radiotherapy for oral cavity cancer who required opioids for cancer treatment related pain are at minimal risk for new dependency. Judicious pain management should be applied for patients with a history of prior opioid use. Larger patient cohorts will be needed to identify patient, disease, and treatment characteristics associated with new persistent use given its limited incidence.

Positive Predictive Value of PET CT in HPV Associated Oropharyngeal Cancers Treated with Definitive Proton Therapy

PURPOSE/OBJECTIVE(S)

Proton therapy (PT) offers attractive dosimetric advantages but there is emerging literature suggesting relative biological effectiveness (RBE) differences at the distal end of the Bragg peak may result in increased posttreatment FDG avidity. While the utility of PET CT is well established, lingering posttreatment inflammation from PT may affect the interpretation of posttreatment scans (PTS). We seek to characterize the positive predictive value (PPV) and negative predictive value (NPV) for residual disease/locoregional recurrence in patients undergoing definitive PT with HPV associated oropharyngeal cancer.

MATERIALS/METHODS

We performed a single institution retrospective analysis of patients with HPV associated oropharyngeal cancer treated with PT between 2016-2022. Patients were included if they had both pretreatment and initial posttreatment restaging PET/CT available for analysis. SUVmax was recorded in both the primary tumor and involved lymph nodes. Patients were considered to have a positive PET CT if there was an SUV decrease of less than 65% from the baseline exam or if there was SUV > 4.0 based on thresholds defined by previous studies. Chi-square analysis was used to compare patients who had a positive PTS to those who did not.

RESULTS

Sixty-two patients were included for analysis with a median age of 62. The entire cohort had a median follow up of 21 months (Range 2-71 months) of whom 86% received chemotherapy. Eleven patients (17%) had PTS defined as positive, of whom only one (PPV 9%) was found to have residual/locoregionally recurrent disease within an area of FDG avidity on PTS. Another patient developed a new primary tumor 9 months later in an area outside of FDG avidity on PTS. The remainder were followed with serial clinical exam with or without the compliment of repeat imaging. They remained without evidence of residual/locoregionally recurrent disease at the time of last follow up. Fifty-one patients had negative posttreatment scans, with only one patient having residual/locoregionally recurrent disease (NPV 98%). On Chi-square analysis T1-2 vs T3-4 tumor, use of CTV margin vs no margin, chemotherapy vs no chemotherapy, smoking history, and tonsil vs base of tongue subsite were not statistically significant in association with positive PTS.

CONCLUSION

PET/CT for post-treatment evaluation of patients treated with PT had an expectedly high NPV of 98% for residual/locoregionally recurrent disease; however, the PPV was 9% (1/11) which is much lower than would be expected with photon-based treatment. These findings may be the result of lingering acute inflammation caused by RBE differences at the distal end of the Bragg peak. Our findings are hypothesis generating and require validation with larger well-matched patient cohorts.

Comprehensive Analysis Reveals No Significant Correlation Between p16/CDKN2A Expression and Treatment Outcomes in Laryngeal Squamous Cell Carcinoma

BACKGROUND

The p16/CDKN2A protein is being explored as an independent prognostic marker in laryngeal cancer, with studies suggesting that p16-positive patients may have a better prognosis. While its role is well-established in oropharyngeal squamous cell carcinoma (OPSCC) related to HPV, ongoing research indicates its potential prognostic value in laryngeal cancer, even in HPV-negative cases.

METHODS

In this study, we investigated the association between survival outcomes and p16 expression in a cohort of 310 laryngeal cancer patients from the Cancer Genome Atlas (TCGA) Program and the University of Maryland Medical Center (UMMC).

RESULTS

In the TCGA cohort, patients with high p16 protein expression had a significantly higher probability of disease-free survival (DFS) at 89%, compared to 51% in the low p16 protein group (p = 0.0266). Additionally, the mean relative p16 protein expression decreased significantly with advancing TNM stage, measured at 1.116 for stage II, 1.075 for stage III, and 0.6204 for stage IV (p = 0.7871 for stage II vs. stage III, p = 0.0065 for stage III vs. stage IV, p = 0.0031 for stage I vs. stage IV). Protein expression for p16 also correlated with CDKN2A retention/deletion status (p = 0.0077), where the DFS was higher in patients with retained CDKN2A than those with deleted CDKN2A (p = 0.0187). Multivariate analysis of the UMMC and TCGA cohorts revealed that both an increase in the patient's age and higher T stage significantly increased the risk of mortality (p = 0.05, p = 0.01, respectively).

CONCLUSION

While this study observes trends suggesting that low p16 protein expression is associated with longer DFS and advanced TNM stage in laryngeal cancer, the multivariate analysis did not establish p16 as an independent prognostic factor. These findings suggest that while p16 may have a biological role in tumor progression, its utility as a standalone prognostic marker in clinical outcomes requires further validation.

Evaluation of intrafraction couch shifts for proton treatment delivery in head-and-neck cancer patients: Toward optimal imaging frequency

PURPOSE

Treatment planning for head-and-neck (H&N) cancer, in particular oropharynx, nasopharynx, and paranasal sinus cases, at our center requires noncoplanar proton beams due to the complexity of the anatomy and target location. Targeting accuracy for all beams is carefully evaluated by using image guidance before delivering proton beam therapy (PBT). In this study, we analyzed couch shifts to evaluate whether imaging is required before delivering each field with different couch angles.

METHODS

After the Institutional Review Board approval, a retrospective analysis was performed on data from 28 H&N patients treated with PBT. Each plan was made with two-to-three noncoplanar and two-to-three coplanar fields. Cone-beam computed tomography and orthogonal kilovoltage (kV) images were acquired for setup and before delivering each field, respectively. The Cartesian (longitudinal, vertical, and lateral) and angular (pitch and roll) shifts for each field were recorded from the treatment summary on the first two fractions and every subsequent fifth fraction. A net magnitude of the three-dimensional (3D) shift in Cartesian coordinates was calculated, and a 3D vector was created from the 6 degrees of freedom coordinates for transforming couch shifts in the system coordinate to the beam's-eye view.

RESULTS

A total of 3219 Cartesian and 2146 angular shift values were recorded for 28 patients. Of the Cartesian shifts, 2069 were zero (64.3%), and 1150 (35.7%) were nonzero (range, -7 to 11 mm). Of the angular shifts, 1034 (48.2%) were zero, and 1112 (51.8%) were nonzero (range, -3.0° to 3.2°). For 17 patients, the couch shifts increased toward the end of the treatment course. We also found that patients with higher body mass index (BMI) presented increased net couch shifts (p < 0.001). With BMI < 27, all overall net shift averages were <2 mm, and overall maximum net shifts were <6 mm.

CONCLUSIONS

These results confirm the need for orthogonal kV imaging before delivering each field of H&N PBT at our center, where a couch rotation is involved.

Disease and toxicity outcomes for a modern cohort of patients with squamous cell carcinoma of cutaneous origin involving the parotid gland: Comparison of volumetric modulated arc therapy and pencil beam scanning proton therapy

OBJECTIVES

We sought to describe outcomes for locally advanced cutaneous squamous cell carcinoma (SCC) involving the parotid treated with volumetric modulated arc therapy (VMAT) versus pencil beam scanning proton beam therapy (PBT).

MATERIALS AND METHODS

Patients were gathered from 2016 to 2022 from 5 sites of a large academic RT department; included patients were treated with RT and had parotid involvement by: direct extension of a cutaneous primary, parotid regional spread from a previously or contemporaneously resected but geographically separate cutaneous primary, or else primary parotid SCC (with a cutaneous primary ostensibly occult). Acute toxicities were provider-reported (CTCAE v5.0) and graded at each on treatment visit. Statistical analyses were conducted.

RESULTS

Median follow-up was 12.9 months (1.3 - 72.8); 67 patients were included. Positive margins/extranodal extension were present in 34 cases; gross disease in 17. RT types: 39 (58.2 %) VMAT and 28 (41.8 %) PBT. Concurrent systemic therapy was delivered in 10 (14.9 %) patients. There were 17 treatment failures (25.4 %), median time of 168 days. Pathologically positive neck nodes were associated with locoregional recurrence (p = 0.015). Oral cavity, pharyngeal constrictor, and contralateral parotid doses were all significantly lower for PBT. Median weight change was -3.8 kg (-14.1 - 5.1) for VMAT and -3 kg (-16.8 - 3) for PBT (p = 0.013). Lower rates of ≥ grade 1 xerostomia (p = 0.002) and ≥ grade 1 dysguesia (p < 0.001) were demonstrated with PBT.

CONCLUSIONS

Cutaneous SCC involving the parotid can be an aggressive clinical entity despite modern multimodal therapy. PBT offers significantly lower dose to organs at risk compared to VMAT, which seemingly yields diminished acute toxicities.

Abstract PO-017: Evaluating the impact of the coronavirus (COVID-19) pandemic on treatment paradigms in head and neck cancer at a tertiary care hospital

Objective: The study aimed to assess the impact of the coronavirus (COVID-19) pandemic on head and neck oncologic care at a tertiary care hospital. The pandemic caused by the novel severe acute respiratory syndrome coronavirus (SARS-CoV-2) has led to policies designed to limit its spread. Policies including eliminating routine appointments, statewide stay-at-home orders, and restricting surgical cases to emergent surgeries have limited access to care. Therefore, we hypothesized that treatment modifications would be implemented for patients and cancer consultations would decrease compared to historical data.

Methods: Information regarding treatment modifications was collected prospectively during interdepartmental tumor conferences from March 18, 2020 to May 20, 2020. Information regarding patient demographics, tumor characteristics, and incidence of new cancer consultations was collected via chart review. Treatment modifications were categorized as follows: Elimination of Systemic Therapy, Treatment Delay, Change to Non-Surgical Management, or Alteration in Adjuvant Therapy. Rationales for modification were similarly grouped as follows: Operating Room Limitations, Medical Co-Morbidities, COVID-19 positive, Patient concern, or System limitations. We determined the rate of treatment modifications and the frequencies of rationales and modification types. Demographic and tumor characteristics were compared between this population and a retrospectively collected cohort from 2019.

Results: 117 patients were presented during the review period in 2020. There were 69 patients presented across the same time period in 2019. There were no differences in demographic characteristics between the groups. There was no difference between the tumor or nodal stages of the presented cases year over year. During the 2020 time period there were more total case presentations and new cancer cases compared to the 2019 time period. Of the 117 cases presented during the study period, there were 10/117 (8.4%) treatment modifications. The most common reason for modification was limited PPE supply. The most common modification was treatment delay. The second most common modification was change from primary surgical management to nonsurgical management. Treatment modifications occurred most commonly early in the review period and declined subsequently.

Conclusions: Despite the ongoing pandemic and resulting state and institutional restrictions, there was no appreciable reduction in new cancer consultations for head and neck cancer. There were a small number of treatment modifications, particularly early in the course of our state and institutional response to the virus. However, over the 2-month period examined, patient care for these patients remained largely unaffected. While the restriction in elective surgical care was implemented across the state of Maryland, the oncologic triage and emergency surgery prioritization sustained the volume of oncologic practice.

Citation Format: Joshua A. Thompson, Reju Joy, Joshua E. Lubek, Ranee Mehra, Jason K. Molitoris, Rodney J. Taylor, Jeffrey S. Wolf, Matthew E. Witek, Kyle M. Hatten. Evaluating the impact of the coronavirus (COVID-19) pandemic on treatment paradigms in head and neck cancer at a tertiary care hospital [abstract]. In: Proceedings of the AACR Virtual Meeting: COVID-19 and Cancer; 2020 Jul 20-22. Philadelphia (PA): AACR; Clin Cancer Res 2020;26(18_Suppl):Abstract nr PO-017.