Radiation-based Therapy Research Articles

Risk Factors for Functional Outcomes in Advanced Laryngeal Squamous Cell Carcinoma.

Chemoradiation for patients with laryngeal squamous cell carcinoma (SCC) may achieve organ preservation, but appropriate patient selection remains unknown. This study investigates pre-treatment risk factors associated with functional and survival outcomes after radiation-based therapy in patients with advanced laryngeal SCC. A retrospective cohort study was performed on 75 adult patients with stage III or IV laryngeal SCC receiving definitive radiation-based therapy from 1997 to 2016 at a tertiary care center. Tracheostomy and gastrostomy dependence were the primary functional outcomes. Multivariable logistic regressions were performed to evaluate relationships between pre-treatment factors and tracheostomy and gastrostomy dependence. Time-to-event analyses were performed to determine risk factors associated with overall survival. Among 75 patients included in the analysis, 30 (40%) patients were tracheostomy dependent and 31 (41%) were gastrostomy tube dependent. The median length of follow-up was 31 months (range=1 to 142 months). Pre-treatment tracheostomy was a significant predictor of post-treatment tracheostomy (aOR=13.9, 95% CI=3.35 to 57.5) and moderate-severe comorbidity was a significant predictor of post-treatment gastrostomy dependence (aOR=2.96, 95% CI=1.04 to 8.43). The five-year overall survival was 51% (95% CI=38 to 64%). Pre-treatment gastrostomy tube dependence was associated with an increased risk of death (aHR=2.45, 95% CI=1.09 to 5.53). Baseline laryngeal functional status and overall health in advanced laryngeal SCC are associated with poor functional outcomes after radiation-based therapy, highlighting the importance of patient selection when deciding between surgical and non-surgical treatment plans. Laryngoscope, 133:594-600, 2023.

Modulation of Secondary Cancer Risks from Radiation Exposure by Sex, Age and Gonadal Hormone Status: Progress, Opportunities and Challenges

Available data on cancer secondary to ionizing radiation consistently show an excess (2-fold amount) of radiation-attributable solid tumors in women relative to men. This excess risk varies by organ and age, with the largest sex differences (6- to more than 10-fold) found in female thyroid and breasts exposed between birth until menopause (~50 years old) relative to age-matched males. Studies in humans and animals also show large changes in cell proliferation rates, radiotracer accumulation and target density in female reproductive organs, breast, thyroid and brain in conjunction with physiological changes in gonadal hormones during the menstrual cycle, puberty, lactation and menopause. These sex differences and hormonal effects present challenges as well as opportunities to personalize radiation-based treatment and diagnostic paradigms so as to optimize the risk/benefit ratios in radiation-based cancer therapy and diagnosis. Specifically, Targeted Radionuclide Therapy (TRT) is a fast-expanding cancer treatment modality utilizing radiopharmaceuticals with high avidity to specific molecular tumor markers, many of which are influenced by sex and gonadal hormone status. However, past and present dosimetry studies of TRT agents do not stratify results by sex and hormonal environment. We conclude that cancer management using ionizing radiation should be personalized and informed by the patient sex, age and hormonal status.

An emerging role of radiation‑induced exosomes in hepatocellular carcinoma progression and radioresistance (Review).

The incidence rates of hepatocellular carcinoma (HCC) worldwide are increasing, and the role of radiotherapy is currently under discussion. Radioresistance is one of the most important challenges in the therapy of HCC compared with other local advanced, recurrent and metastatic cancers. The mechanisms of radioresistance are complex and remain to be fully understood; however, extracellular vesicles have been investigated in recent studies. Exosomes, which are 40- to 150-nm extracellular vesicles released by cancer cells, contain multiple pathogenic components, including proteins, nucleic acids and lipids, and play critical functions in cancer progression. Emerging data indicate a diagnosis potential for exosomes in HCC, since radiation-derived exosomes promote radioresistance. Radiation-based therapy alters the contents and components of exosomes, suggesting that exosomes and their components may serve as prognostic and predictive biomarkers to monitor radiation response. Therefore, understanding the roles and mechanisms of exosomes in HCC progression and radiation response during HCC therapy may increase our knowledge concerning the roles of exosomes in radioresistance, and may lead to novel approaches for HCC prognosis and treatment. The current review summarizes recent studies on exosome involvement in HCC and the molecular changes in exosome components during HCC progression. It also discusses the functions of exosomes in HCC therapy, and highlights the importance of exosomes in HCC progression and resistance for the development of novel therapies.

Intraoperative Radiation After Pelvic Short Course Radiation-Based Total Neoadjuvant Therapy for Patients With Rectal Adenocarcinoma at High Risk for Local Recurrence

BackgroundShort course radiation-based total neoadjuvant therapy can improve disease-free survival for patients with high-risk locally advanced rectal cancer. Tumors that involve or threaten the circumferential resection margin have a particularly high risk of local recurrence. Intraoperative radiation therapy enables treatment escalation at the threatened or involved margin at the time of surgery. Patients and MethodsPatients with rectal adenocarcinoma treated with preoperative short course radiotherapy-based total neoadjuvant therapy and intraoperative radiation at the time of surgery were identified. All patients had a threatened or involved circumferential resection margin on magnetic resonance imaging at the time of diagnosis. Treatment details, radiation toxicities, postoperative complications and oncologic outcomes were recorded. ResultsTen patients received intraoperative radiation after short course radiation-based total neoadjuvant therapy. All patients had an involved or threatened circumferential resection margin, 60% had extramural venous invasion, and 60% had positive lateral pelvic lymph nodes. Seven patients had negative surgical margins (≥ 2 mm), and 3 patients had an R1 resection with radial margins < 2 mm. The median [IQR] length of hospitalization after surgery was 11 [7-14] days. Three patients required readmission and 2 patients required reoperation due to complications including anastamotic leak and abscess. With a median follow up of 19.5 months postoperatively, no patient developed a pelvic recurrence, and 6 patients developed distant recurrences. ConclusionsThe use of intraoperative radiation after a short course radiotherapy-based neoadjuvant therapy is safe and feasible. Further data are needed to determine whether the addition of intraoperative radiation improves local recurrence rates over preoperative radiation alone.

What Is the Optimal Bridging Therapy for Patients with Hepatitis C-associated Hepatocellular Carcinoma Awaiting Liver Transplant? An Analysis of the United States HCC Liver Transplantation Consortium

Introduction: Patients with hepatitis C (HCV)-associated hepatocellular carcinoma (HCC) often receive bridging therapy in the form of liver-directed therapy (LDT) while awaiting liver transplant (LT). The optimal modality of LDT, with respect to both cancer outcomes and response to direct-acting antiviral (DAA) therapy, remains unknown. Methods: The United States HCC Liver Transplantation Consortium was queried for patients with primary HCV-associated HCC within Milan criteria who completed DAA therapy and underwent LT. Primary outcomes were HCC recurrence-free survival (RFS) and overall survival (OS). Secondary outcome was sustained virologic response (SVR) as indicator of efficacy of DAA therapy. Results: Of 857 patients, 753 met inclusion criteria. LDT consisted of radiofrequency ablation (RFA,13.3%,N=100), transarterial chemoembolization (TACE,44.1%,N=332), yttrium-90 (Y90,4.8%,N=36), and stereotactic body radiation therapy (SBRT,2.9%,N=22). Eighty-one(10.8%) patients received no LDT and 182(24.2%) received multiple modalities. SBRT patients had the highest 5-year RFS(100%) followed by those receiving TACE(94%), Y90(91.4%), RFA(89.9%), and multiple therapies(88.2%) (p=0.048, Figure 1A). OS was higher among patients who received SBRT, but not statistically significant (p=0.685, Figure 1B). SVR rate was lower among radiation-based therapy groups (Y90 73.5%, SBRT 78.9%, others≥88%; p=0.046). Conclusions: In a homogeneous population of HCV-associated HCC patients within Milan criteria who received bridging therapy while awaiting LT, SBRT was associated with increased RFS and trended towards increased OS. However, radiation-based therapy was associated with decreased efficacy of DAA as measured by lower SVR rates. The optimal choice of bridging therapy to liver transplant must balance oncologic and virologic outcomes, but these findings seem to favor SBRT.

Local ablative treatment with surgery and/or radiotherapy in single-site and oligometastatic carcinoma of unknown primary

BackgroundSingle-site carcinoma of unknown primary (CUP) is recognised as a distinct favourable subtype in the European Society of Medical Oncology (ESMO) classification. There is broad consensus that these patients are candidates for local ablative treatment strategies with surgery and/or radiotherapy, but data on their outcomes are scarce. Patients and methodsIn this study, we have addressed the prospects of cure and prognostic factors in a retrospective cohort of 63 patients who were eligible for local treatment at our centre. ResultsMedian event-free (EFS) and overall survival (OS) were 15.6 months and 52.5 months, respectively. Of 61 patients who received local treatment, 20 (32.8%) remained event-free over a median follow-up of 28 months. Baseline clinical parameters including affected organ, number, volume and histology of metastases had no significant impact on prognosis, whereas deleterious TP53 mutations and DNA copy number loss emerged as independent adverse risk factors with respect to EFS. Surgical treatment was associated with improved OS as compared to radiation-based therapy. ConclusionOur study advocates to pursue localised treatment with surgery and/or radiotherapy whenever feasible and implies that genetic parameters might additionally determine the clinical course of single-site CUP patients.

Treatment trends for advanced oropharyngeal squamous cell carcinoma in the era of human papillomavirus.

Given recent increase in prevalence of oropharyngeal squamous cell carcinoma (OPSCC) and advances in surgical capabilities, we sought to determine whether a change in frequency of surgery-based treatment for locally advanced OPSCC has occurred. Patients with T3-T4b OPSCC in the National Cancer Database diagnosed from 2010 to 2016 were categorized as receiving primary surgery or radiation-based therapy and stratified by human papillomavirus (HPV) status. Trends in treatment selection and factors associated with treatment type were examined. 6566 patients with HPV-positive were included, of whom 489 (7.45%) received surgery and 4698 patients with HPV-negative, of whom 362 (7.71%) received surgery. The percentage of patients treated with surgery decreased from 11.8% to 5.9% for HPV-positive disease and from 9.8% to 6.3% for HPV-negative disease. Factors associated with surgery included younger age, health insurance, and treatment at academic centers. In HPV-positive and HPV-negative disease, the percentage of locally advanced OPSCC undergoing surgery-based therapy has decreased.

History of whole pelvis plus para-aortic radiation is a risk factor associated with febrile neutropenia during chemotherapy for recurrent cervical cancer.

Radiation-based therapy is widely used for advanced cervical cancer. Prior radiation-based therapy is a potential risk factor for febrile neutropenia (FN). However, the effect of irradiation field size on the incidence of FN during recurrent cervical cancer treatment is unclear. This study aimed to investigate the relationship between prior irradiation field size and FN development during recurrent chemotherapy. This retrospective, observational study included cervical cancer patients who received recurrent chemotherapy between November 2006 and June 2020. The patients were classified into two groups based on the area of irradiation fields. The first group included patients with a history of whole pelvis (WP) irradiation (WP group). The second group had patients who underwent WP plus para-aortic lymph node (PAN) irradiation (WP + PAN group). The incidences of hematological toxicities and FN during the recurrent chemoradiotherapy were compared between the two groups. The FN incidence was significantly higher in the WP + PAN group than in the WP group (32.1% vs. 0%, P < 0.001). The incidence of Grade 4 neutropenia was not significantly different between the WP + PAN and WP groups. The nadir absolute neutrophil counts were significantly lower and the dose reduction or discontinuation rate of chemotherapy was significantly higher in the WP + PAN group than in the WP group. History of WP plus PAN radiation is a risk factor for developing FN during recurrent cervical cancer chemotherapy.

High neutrophil-to-lymphocyte ratio is a predictor of short-term survival for patients with recurrent cervical cancer after radiation-based therapy.

Patients with recurrent cervical cancer after radiotherapy have poor prognoses because of the lack of effective treatment options. Biomarkers to predict survival outcomes for recurrent cervical cancer are warranted because patients with limited life expectancy sometimes benefit from less aggressive treatment in combination with early palliative care. Therefore, we aimed to explore a predictive biomarker for the outcomes of patients with recurrent cervical cancer. We retrospectively investigated 231 patients initially treated with radiation-based therapy between January 2004 and December 2015. The associations between clinicopathological features at the time of relapse and overall survival after relapse were assessed. As factors which reflect patients' conditions, we particularly focused on C-reactive protein-to-albumin ratio (CAR) and neutrophil-to-lymphocyte ratio (NLR) at the time of relapse. Additionally, we investigated biomarkers predictive of short-term survival. Among 231 patients, 91 patients experienced relapse and 74 patients died during the follow-up period. Multivariate analysis revealed that treatment after relapse, CAR, and NLR was significantly associated with overall survival. Among them, treatment after relapse significantly affected survival outcomes, and patients who received definitive local treatment had a better 3-year survival rate than those who received other treatments. Conversely, NLR was the most influential biomarker for short-term survival, and the prognosis of patients with high NLRs was much worse than those with low NLRs. This study thus demonstrated that, for the patients with recurrent cervical cancer who received radiation-based therapy, definitive local treatment can provide long-term survival and extremely high NLRs are predictive of short-term survival.

Fancy-Shaped Gold-Platinum Nanocauliflowers for Improved Proton Irradiation Effect on Colon Cancer Cells.

Enhancing the effectiveness of colorectal cancer treatment is highly desirable. Radiation-based anticancer therapy—such as proton therapy (PT)—can be used to shrink tumors before subsequent surgical intervention; therefore, improving the effectiveness of this treatment is crucial. The addition of noble metal nanoparticles (NPs), acting as radiosensitizers, increases the PT therapeutic effect. Thus, in this paper, the effect of novel, gold–platinum nanocauliflowers (AuPt NCs) on PT efficiency is determined. For this purpose, crystalline, 66-nm fancy shaped, bimetallic AuPt NCs were synthesized using green chemistry method. Then, physicochemical characterization of the obtained AuPt NCs by transmission electron microscopy (TEM), selected area electron diffraction (SAED), energy dispersive X-ray spectroscopy (EDS), and UV-Vis spectra measurements was carried out. Fully characterized AuPt NCs were placed into a cell culture of colon cancer cell lines (HCT116, SW480, and SW620) and a normal colon cell line (FHC) and subsequently subjected to proton irradiation with a total dose of 15 Gy. The 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS) test, performed after 18-h incubation of the irradiated cell culture with AuPt NCs, showed a significant reduction in cancer cell viability compared to normal cells. Thus, the radio-enhancing features of AuPt NCs indicate their potential application for the improvement in effectiveness of anticancer proton therapy.

Radiation-Based Approaches As an Alternative to Stem Cell Transplant for Relapsed/Refractory Classical Hodgkin Lymphoma: A Multicenter Retrospective Analysis

Radiation-Based Approaches As an Alternative to Stem Cell Transplant for Relapsed/Refractory Classical Hodgkin Lymphoma: A Multicenter Retrospective Analysis

Refining assessment of response to radiation-based therapy for muscle-invasive bladder cancer: Is post-treatment tumor bed biopsy always necessary?

IntroductionRadiation-based therapy (RT) has emerged as a suitable alternative to radical cystectomy (RC) and pelvic lymph node dissection for muscle-invasive bladder cancer (MIBC) patients. Routine biopsy after RT to rule out residual disease remains inconsistent across guidelines. Our objective was to review the significance of a bladder biopsy in terms of assessment of response post-RT and its potential impact on survival. Patients and methodsThis was a single-center retrospective study on patients with MIBC (cT2-4aN0-2M0) treated with curative intent RT. A total of 169 patients with primary urothelial carcinoma were analyzed. Patients’ demographic, clinical and pathological variables, imaging, cystoscopy, urine cytology, and biopsy reports after RT were collected and compiled. Whenever urine cytology was positive or cystoscopy showed any malignant-appearing lesion, the first assessment post-RT was considered suspicious for residual disease. A descriptive population analysis was reported. Cox regression multivariable analysis was performed to identify independent variables associated with survival outcomes. ResultsMedian age was 75 years (interquartile range 66–82) and clinical staging was cT2 in 152 (90%) patients. Cytology and cystoscopy were normal in 140 (83%) after RT. Of patients with a control biopsy, residual MIBC was present in 3 (5%) and non-MIBC in another 6 (11%). On the contrary, a for-cause biopsy due to a suspicious assessment post-RT did not yield residual cancer in 45% of patients. Multivariable analysis showed that age (hazard ratio [HR] 1.04, P< 0.001), lymphovascular invasion (HR 1.68, P = 0.03) and a suspicious assessment after RT (HR 3.21; P< 0.001) were significantly associated with worse OS. This study was limited by its retrospective design. ConclusionsA routine biopsy after RT may be warranted to assess treatment response. This might be particularly important for patients who may benefit from early surgical intervention for residual MIBC. Further prospective studies are needed to confirm our findings.

Ipsilateral radiation for squamous cell carcinoma of the tonsil: American Radium Society appropriate use criteria executive summary.

We conducted the current systemic review to provide up-to-date literature summary and optimal evidence-based recommendations for ipsilateral radiation for squamous cell carcinoma of the tonsil. We performed literature search of peer-reviewed journals through PubMed. The search strategy and subject-specific keywords were developed based on the expert panel's consensus. Articles published from January 2000 to May 2020 with full text available on PubMed and restricted to the English language and human subjects were included. Several prespecified search terms were used to identify relevant publications and additional evidence published since the initial American College of Radiology Appropriateness Criteria Ipsilateral Tonsil Radiation recommendation was finalized in 2012. The full bibliographies of identified articles were reviewed and irrelevant studies were removed. The initial search and review returned 46 citations. The authors added three citations from bibliographies, websites, or books not found in the literature search. Of the 49 citations, 30 citations were retained for further detailed review, and 14 of them were added to the evidence table. Articles were removed from the bibliography if they were not relevant or generalizable to the topic, or focused on unknown primary disease. Several commonly encountered clinical case variants were created and panelists anonymously rated each treatment recommendation. The results were reviewed and disagreements discussed. The panel provided updated evidence and recommendations for ipsilateral radiation for squamous cell carcinoma of the tonsil in the setting of primary radiation-based therapy and postoperative adjuvant radiotherapy. This committee did not reach agreements for some case variants due to a lack of strong evidence supporting specific treatment decisions, indicating a further need for research in these topics.

Near-Infrared Radiation-Based Mild Photohyperthermia Therapy of Non-Melanoma Skin Cancer with PEGylated Reduced Nanographene Oxide.

Using a one-step thermal reduction and non-covalent chemical functionalization process, PEGylated reduced nanographene oxide (rGOn-PEG) was produced from nanographene oxide (GOn) and characterized in terms of particle size, dispersion stability, chemistry, and photothermal properties, in view of its use for photothermal therapy (PTT) of non-melanoma skin cancer. GOn infrared spectrum presented more intense bands assigned to oxygen containing functional groups than observed for rGOn-PEG. GOn C/O ratio decreased more than 50% comparing with rGOn-PEG and nitrogen was present in the latter (N at % = 20.6) due to introduction of PEG-NH2. Thermogravimetric analysis allowed estimating the amount of PEG in rGOn-PEG to be of about 56.1%. Simultaneous reduction and PEGylation increased the lateral dimensions from 287 ± 139 nm to 521 ± 397 nm, as observed by transmission electron microscopy and dynamic light scattering. rGOn-PEG exhibited ≈13-fold higher absorbance in the near-infrared radiation (NIR) region, as compared to unmodified GOn. Low power (150 mW cm−2) NIR irradiation using LEDs resulted in rGOn-PEG heating up to 47 °C, which is within the mild PTT temperature range. PEGylation strongly enhanced the dispersibility of rGOn in physiological media (phosphate buffered saline, fetal bovine serum, and cell culture medium) and also improved the biocompatibility of rGOn-PEG, in comparison to GOn (25–250 μg mL−1). After a single NIR LED irradiation treatment of 30 min, a decrease of ≈38% in A-431 cells viability was observed for rGOn-PEG (250 μg mL−1). Together, our results demonstrate the potential of irradiating rGOn-PEG using lower energy, cheaper, smaller, and safer LEDs, as alternative to high power lasers, for NIR mild hyperthermia therapy of cancer, namely non-melanoma skin cancer.

Overexpression of RPN2 suppresses radiosensitivity of glioma cells by activating STAT3 signal transduction

BackgroundRadiation therapy is the primary method of treatment for glioblastoma (GBM). Therefore, the suppression of radioresistance in GBM cells is of enormous significance. Ribophorin II (RPN2), a protein component of an N-oligosaccharyl transferase complex, has been associated with chemotherapy drug resistance in multiple cancers, including GBM. However, it remains unclear whether this also plays a role in radiation therapy resistance in GBM.MethodsWe conducted a bioinformatic analysis of RPN2 expression using the UCSC Cancer Genomics Browser and GEPIA database and performed an immunohistochemical assessment of RPN2 expression in biopsy specimens from 34 GBM patients who had received radiation-based therapy. We also studied the expression and function of RPN2 in radiation-resistant GBM cells.ResultsWe found that RPN2 expression was upregulated in GBM tumors and correlated with poor survival. The expression of RPN2 was also higher in GBM patients with tumor recurrence, who were classified to be resistant to radiation therapy. In the radiation-resistant GBM cells, the expression of RPN2 was also higher than in the parental cells. Depletion of RPN2 in resistant cells can sensitize these cells to radiation-induced apoptosis, and overexpression of RPN2 had the reverse effect. Myeloid cell leukemia 1 (MCL1) was found to be the downstream target of RPN2, and contributed to radiation resistance in GBM cells. Furthermore, STAT3 was found to be the regulator of MCL1, which can be activated by RPN2 dysregulation.ConclusionOur study has revealed a novel function of RPN2 in radiation-resistant GBM, and has shown that MCL1 depletion or suppression could be a promising method of therapy to overcome the resistance promoted by RPN2 dysregulation.

Radiation Necrosis in Intracranial Lesions.

Radiation necrosis (RN) is a challenging potential complication of cranial radiation therapy. Believed to result from a complex interplay of vascular, glial, and immunologic factors, the exact mechanism of RN remains unclear. Patients who develop RN typically have a history of treatment with stereotactic radiation surgery or some other form of radiation-based therapy. The time frame for its development is variable, but it most often occurs one to three years following radiation therapy. Reported treatment doses capable of inducing radiation necrosis are variable, with higher doses per fraction more likely to induce RN. Furthermore, RN remains a challenging diagnosis for clinicians to make, as its presentation is often nonspecific and imaging studies might not clearly differentiate RN from tumor recurrence or pseudoprogression. RN is initially managed with corticosteroids, followed by bevacizumab, surgical resection, or laser interstitial thermal therapy if symptoms persist. In this review, we examine the literature regarding pathophysiology, incidence, imaging characteristics, and management strategies for radiation necrosis.

PD60-01 DEFINITIVE RADIATION-BASED THERAPY FOR MUSCLE-INVASIVE BLADDER CANCER: THE CANADIAN MULTICENTER EXPERIENCE

INTRODUCTION AND OBJECTIVE:Radiation-based therapy (RT) is a suitable bladder-preserving alternative to radical cystectomy (RC) for patients with muscle-invasive bladder cancer (MIBC) and is contin...

Role of radiotherapy in watch and wait strategy after neoadjuvant trerapy for rectal cancer

For locally advanced (T3-4/N+M0) rectal cancer (LARC), radiation-based neoadjuvant therapy followed by total mesorectal excision (TME) is the standard treatment. For those who achieved clinical complete response (cCR), a non-operative management called "watch and wait" (W&W) strategery can preserve organ function and improve the life quality. For W&W strategy, radiotherapy is still the core part of neoadjuvant therapy. To increase the tumor response grade and cCR rate is the goal of optimized neoadjuvant regimens. In this review, we summarized the role of radiotherapy in the W&W strategy and discussed the advances of optimized radiation-based neoadjuvant therapy to achieve higher cCR rate, including new radiosensitizing agents, induction and consolidation chemotherapy, combination with immunotherapy, and prolonged interval time. All of the above efforts aim to improve patient survival and quality of life.

Tumor biology and multidisciplinary strategies of oligometastasis in gastrointestinal cancers.

More than 70% of gastrointestinal (GI) cancers are diagnosed with metastases, leading to poor prognosis. For some cancer patients with limited sites of metastatic tumors, the term oligometastatic disease (OMD) has been coined as opposed to systemic polymetastasis (PMD) disease. Stephan Paget first described an organ-specific pattern of metastasis in 1889, now known as the "seed and soil" theory where distinct cancer types are found to metastasize to different tumor-specific sites. Our understanding of the biology of tumor metastasis and specifically the molecular mechanisms driving their formation are still limited, in particular, as it relates to the genesis of oligometastasis. In the following review, we discuss recent advances in general understanding of this metastatic behavior including the role of specific signaling pathways, various molecular features and biomarkers, as well as the interaction of carcinoma cells with their tissue microenvironments (both primary and metastatic niches). The unique features that underlie OMD provide potential targets for localized therapy. As it relates to clinical practice, OMD is emerging as treatable with surgical resection and/or other local therapy options. Strategies currently being applied in the clinical management of OMD will be discussed including surgical, radiation-based therapy, ablation procedures, and the results of emerging clinical trials involving immunotherapy.

Abstract 4942: Variations in HPV function are associated with patient outcome and identify new candidate therapeutic approaches

Abstract Human papilloma virus (HPV) is an oncogenic driver for a subset of head and neck squamous cell carcinomas (HNSCC), primarily from the oropharyngeal tissue subsite (OPSCC). These tumors are increasing in incidence and have recently surpassed cervical cancer as the most common HPV-driven malignancy in the United States. Fortunately, these tumors generally respond well to radiation-based therapy (XRT), and long-term (5 yr) survival is around 85%. However, the XRT treatment can generate significant morbidity, including problems with speech and swallowing. There is a clinical effort to reduce the treatment-related morbidity without compromising survival outcomes, through de-escalation treatment protocols. However, there is a subset of HPV+ OPSCC patients who do not respond to the current therapies and should not be given less intense treatment. This has generated the need to stratify patients based on their risk of recurrence or death, but currently no molecular biomarkers are available for risk assessment in OPSCC. By analyzing genomic data from The Cancer Genome Atlas (TCGA) we have identified a gene expression signature associated with expression of HPV genes. This signature identified 2 groups within the HPV+ tumors that demonstrate different levels of HPV function. One group seems to have reduced HPV function and present with intermediate phenotypes between HPV+ and HPV- tumors. Importantly, this signature is also highly prognostic in HPV+ OPSCC (p&amp;lt;0.0001) and significant on multivariate analysis (p&amp;lt;0.01). With the tumors showing reduced HPV function having worse outcomes. This prognostic signature was validated in independent OPSCC (p&amp;lt;0.0001) and cervical cancer cohorts (p&amp;lt;0.0026). The signature is most strongly associated with differential expression in the HPV gene E1^E4 but not with expression of the oncogenic driver genes of E6 and E7 genes. In vitro, we have associated the signature with sensitivity to XRT, suggesting a mechanism for the differences in patient outcome. An in vitro high throughput drug screen has identified candidate druggable targets in both the high and low risk groups, with 2 key pathways being cellular metabolism and proteasome function. Single agent and combination treatments targeting these pathways are currently being evaluated. In conclusion, we have identified a novel prognostic signature for HPV+ tumors that is associated with variations in HPV function among patients. This has the potential to translate into a biomarker assay for risk stratification, for use with de-escalation treatment protocols. Additionally, it has identified key functions of HPV that appear to be targetable and could lead to new therapeutic approaches for the subset of HPV+ patients who do not respond to XRT treatment. Citation Format: Frederico O. Gleber-Netto, Meng Gao, Xiayu Rao, Christopher P. Vellano, Joseph R. Marszalek, Jing Wang, Faye M. Johnson, Curtis R. Pickering. Variations in HPV function are associated with patient outcome and identify new candidate therapeutic approaches [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 4942.