Precision Radiotherapy: Reduction in Radiation for Oropharyngeal Cancer in the 30 ROC Trial

Lessons and Opportunities for Biomarker-Driven Radiation Personalization in Head and Neck Cancer

Head and neck cancer is notoriously challenging to treat in part because it constitutes an anatomically and biologically diverse group of cancers with heterogeneous prognoses. While treatment can be associated with significant late toxicities, recurrence is often difficult to salvage with poor survival rates and functional morbidity.^1,2 Thus, achieving tumor control and cure at the initial diagnosis is the highest priority. Given the differing outcome expectations (even within a specific sub-site like oropharyngeal carcinoma), there has been growing interest in personalizing treatment: de-escalation in selected cancers to decrease the risk of late toxicity without compromising oncologic outcomes, and intensification for more aggressive cancers to improve oncologic outcomes without causing undue toxicity. This risk stratification is increasingly accomplished using biomarkers, which can represent molecular, clinicopathologic, and/or radiologic data. In this review, we will focus on biomarker-driven radiotherapy dose personalization with emphasis on oropharyngeal and nasopharyngeal carcinoma. This radiation personalization is largely performed on the population level by identifying patients with good prognosis via traditional clinicopathologic factors, although there are emerging studies supporting inter-tumor and intra-tumor level personalization via imaging and molecular biomarkers.

NR4A3 Expression Is Consistently Absent in Acinic Cell Carcinomas of the Breast: A Potential Nosologic Shift

Acinic cell carcinoma (AciCC) is a tumor that is recognized in both the breast and salivary glands. Recently, the recurrent genomic rearrangement, t(4;9)(q13;q31) was identified in salivary AciCC that results in constitutive upregulation of the nuclear transcription factor NR4A3, which can be detected by immunohistochemistry. In this study, we sought to evaluate NR4A3 expression in breast AciCC using immunohistochemistry. Strong and diffuse nuclear staining was considered a positive result. Sixteen AciCCs were studied, including 8 pure AciCCs and 8 AciCCs admixed with other types (invasive carcinoma of no special type in 5 cases and metaplastic carcinoma in 3 cases). All 16 AciCCs showed negative results for NR4A3 expression. Four cases with available material were evaluated for rearrangements of the NR4A3 gene by fluorescence in situ hybridization and no rearrangements were observed. Whole-genome sequencing of 1 AciCC revealed a TP53 splice-site mutation, high levels of genomic instability, and genomic features of homologous recombination DNA repair defects; a structural variant analysis of this case did not reveal the presence of a t(4;9) rearrangement. We conclude that breast AciCCs consistently lack NR4A3 rearrangement or overexpression, unlike most of the salivary AciCCs, and that consistent with previous results, breast AciCCs are associated with genomic alterations more similar to those seen in triple-negative breast carcinomas than salivary gland AciCCs. These results suggest that unlike other salivary gland-like tumors that occur in the breast, the molecular underpinnings of the salivary gland and breast AciCCs are different and that the salivary gland and breast AciCCs likely represent distinct entities.

Remodeling the tumor microenvironment to overcome treatment resistance in HPV-negative head and neck cancer

Despite intensive efforts and refined techniques, overall survival in HPV-negative head and neck cancer remains poor. Robust immune priming is required to elicit a strong and durable antitumor immune response in immunologically cold and excluded tumors like HPV-negative head and neck cancer. This review highlights how the tumor microenvironment could be affected by different immune and stromal cell types, weighs the need to integrate metabolic regulation of the tumor microenvironment into cancer treatment strategies and summarizes the emerging clinical applicability of personalized immunotherapeutic strategies in HPV-negative head and neck cancer.

Automated tracking of morphologic changes in weekly magnetic resonance imaging during head and neck radiotherapy

BACKGROUND AND PURPOSE

Anatomic changes during head and neck radiotherapy can impact dose delivery, necessitate adaptive replanning, and indicate patient-specific response to treatment. We have developed an automated system to track these changes through longitudinal MRI scans to aid identification and clinical intervention. The purpose of this article is to describe this tracking system and present results from an initial cohort of patients.

MATERIALS AND METHODS

The Automated Watchdog in Adaptive Radiotherapy Environment (AWARE) was developed to process longitudinal MRI data for radiotherapy patients. AWARE automatically identifies and collects weekly scans, propagates radiotherapy planning structures, computes structure changes over time, and reports important trends to the clinical team. AWARE also incorporates manual structure review and revision from clinical experts and dynamically updates tracking statistics when necessary. AWARE was applied to patients receiving weekly T2-weighted MRI scans during head and neck radiotherapy. Changes in nodal gross tumor volume (GTV) and parotid gland delineations were tracked over time to assess changes during treatment and identify early indicators of treatment response.

RESULTS

N = 91 patients were tracked and analyzed in this study. Nodal GTVs and parotids both shrunk considerably throughout treatment (-9.7 ± 7.7% and -3.7 ± 3.3% per week, respectively). Ipsilateral parotids shrunk significantly faster than contralateral (-4.3 ± 3.1% vs. -2.9 ± 3.3% per week, p = 0.005) and increased in distance from GTVs over time (+2.7 ± 7.2% per week, p < 1 × 10^-5 ). Automatic structure propagations agreed well with manual revisions (Dice = 0.88 ± 0.09 for parotids and 0.80 ± 0.15 for GTVs), but for GTVs the agreement degraded 4-5 weeks after the start of treatment. Changes in GTV volume observed by AWARE as early as one week into treatment were predictive of large changes later in the course (AUC = 0.79).

CONCLUSION

AWARE automatically identified longitudinal changes in GTV and parotid volumes during radiotherapy. Results suggest that this system may be useful for identifying rapidly responding patients as early as one week into treatment.

Are we ready for deintensification in human papillomavirus-positive oropharyngeal carcinomas?

PURPOSE OF REVIEW

Excellent outcomes following contemporary treatment of human papillomavirus (HPV)-positive oropharyngeal carcinoma (HPV+ OPC) have prompted the exploration of deintensification approaches to minimize treatment-related toxicities. This review describes the landscape of deintensification to date (up to November 2022).

RECENT FINDINGS

Although several deintensification trials have been published, none are practice changing. Three phase III randomized-controlled trials studying cetuximab and radiation therapy vs. standard chemoradiotherapy all showed inferior outcomes. Although some phase II trials reported favourable outcomes, they are often single-arm trials without an adequate control arm, thereby limiting the ability to modify practice.

SUMMARY

Substantial effort has been expended to explore deintensification options for selected HPV+ OPC patients aiming to avoid unnecessary toxicity. Strategies have included replacing cisplatin with cetuximab, reduced chemotherapy or radiotherapy intensity, reduction of radiotherapy volumes and risk stratification after trans-oral surgery or following induction chemotherapy. Challenges remain in the current deintensification landscape, including identifying the most suitable candidates along with a choice of most appropriate deintensification strategies. Promising selection criteria included either static baseline features or kinetic characteristics of clinical-biological parameters. Practice-changing trials remain elusive, and the search continues to attempt optimization of the therapeutic ratio for these patients.

Visualization of tumor hypoxia and re-oxygenation after stereotactic body radiation therapy in early peripheral lung cancer: A prospective study

BACKGROUND AND PURPOSE

In this study, fluoromisonidazole positron emission tomography (F-MISO PET/CT) was used to evaluate tumor hypoxia and re-oxygenation in patients with lung tumors treated with stereotactic body radiation therapy (SBRT).

MATERIALS AND METHODS

Patients with T1-2 N0 lung cancer were included in this study. The prescribed dose was 48-52 Gy in four fractions. F-MISO PET/CT was performed twice, before SBRT and 1-3 days after the first irradiation. The maximum standardized uptake value (SUVmax) and tumor/muscle ratio (TMR) were evaluated as indicators of hypoxia. The threshold for hypoxia was defined as a TMR of 1.30 or more.

RESULTS

Between 2016 and 2021, 15 patients were included. Pre-treatment tumor hypoxia was observed in nine tumors (60 %). TMR in all six tumors without pre-treatment hypoxia rose after single high-dose irradiation. In contrast, TMR in six of nine tumors with pre-treatment hypoxia dropped after irradiation, suggesting re-oxygenation. Although no local recurrence was noted, regional and/or distant relapses were seen in four patients (27 %). Of these, three had tumors with abnormal F-MISO uptake. The remaining patient had a tumor without signs of hypoxia on pre-treatment PET/CT. The 2-year progression free survival of patients with tumors with and without pre-treatment hypoxia were 30 % and 63 %, respectively (p = 0.319).

CONCLUSION

Tumor hypoxia reduced after single high-dose irradiation. Tumor with F-MISO uptake seems to be an unfavorable prognostic factor in lung SBRT.

Consensuses, controversies, and future directions in treatment deintensification for human papillomavirus-associated oropharyngeal cancer

The most common cancer caused by human papillomavirus (HPV) infection in the United States is oropharyngeal cancer (OPC), and its incidence has been rising since the turn of the century. Because of substantial long-term morbidities with chemoradiation and the favorable prognosis of HPV-positive OPC, identifying the optimal deintensification strategy for this group has been a keystone of academic head-and-neck surgery, radiation oncology, and medical oncology for over the past decade. However, the first generation of randomized chemotherapy deintensification trials failed to change the standard of care, triggering concern over the feasibility of de-escalation. National database studies estimate that up to one third of patients receive nonstandard de-escalated treatments, which have subspecialty-specific nuances. A synthesis of the multidisciplinary deintensification data and current treatment standards is important for the oncology community to reinforce best practices and ensure optimal patient outcomes. In this review, the authors present a summary and comparison of prospective HPV-positive OPC de-escalation trials. Chemotherapy attenuation compromises outcomes without reducing toxicity. Limited data comparing transoral robotic surgery (TORS) with radiation raise concern over toxicity and outcomes with TORS. There are promising data to support de-escalating adjuvant therapy after TORS, but consensus on treatment indications is needed. Encouraging radiation deintensification strategies have been reported (upfront dose reduction and induction chemotherapy-based patient selection), but level I evidence is years away. Ultimately, stage and HPV status may be insufficient to guide de-escalation. The future of deintensification may lie in incorporating intratreatment response assessments to harness the powers of personalized medicine and integrate real-time surveillance.

Clinical use of positron emission tomography for radiotherapy planning - Medical physics considerations

PET/CT imaging plays an increasing role in radiotherapy treatment planning. The aim of this article was to identify the major use cases and technical as well as medical physics challenges during integration of these data into treatment planning. Dedicated aspects, such as (i) PET/CT-based radiotherapy simulation, (ii) PET-based target volume delineation, (iii) functional avoidance to optimized organ-at-risk sparing and (iv) functionally adapted individualized radiotherapy are discussed in this article. Furthermore, medical physics aspects to be taken into account are summarized and presented in form of check-lists.

Concurrent immunoradiation for HPV-associated oropharyngeal squamous cell carcinoma

OBJECTIVES

Current trials for HPV-associated oropharyngeal SCCs (OP-SCCs) are evaluating treatment de-escalation including use of concurrent immunotherapy with radiation therapy (I-RT). Given limited prospective data following I-RT, we aimed to examine this question utilizing the National Cancer Data Base (NCDB).

METHODS

The NCDB was queried for patients with HPV-associated OP-SCCs eligible for current de-escalation studies with AJCC 7th edition T1-T2/N1-N2b and T3/N0-N2b disease. Patients were stratified into I-RT, concurrent chemoradiation (C-RT), and radiation therapy alone (RT) arms. Kaplan-Meier analysis was utilized to compare overall survival (OS) between treatment arms followed by a Cox multivariate (MVA) proportional hazards model controlling for tumor and patient characteristics and propensity-score analyses with inverse probability treatment weighting (IPTW).

RESULTS

We identified 4768 patients; 313 received I-RT, 3660 patients received C-RT, and 795 received RT. Median age was 62 years (range 27-90) with a median Charlson-Deyo co-morbidity score of 0 (range: 0-3). The vast majority were cN1-N2a (88.8%) and 26.5% were cT3. On MVA, inferior 3-year and 8-year OS was noted following I-RT (81.6% and 70.5%) vs. C-RT (90.6% and 79.4%) (HR = 1.69 (95% CI: 1.29-2.21); p < 0.0001) with no significant difference vs. RT (88.1% and 75.8%) (HR = 1.07; p = 0.80). This was also maintained on IPTW-analysis (HR = 1.62 (95% CI: 1.23-2.15); p = 0.001).

CONCLUSIONS

I-RT was associated with significantly poorer OS vs. C-RT with no benefit compared to RT for HPV-associated OP-SCCs. I-RT is not recommended outside of currently accruing clinical trials.

30-day morbidity and mortality after transoral robotic surgery for human papillomavirus (HPV) associated oropharyngeal squamous cell carcinoma: A retrospective analysis of two prospective adjuvant de-escalation trials (MC1273 & MC1675)

OBJECTIVE

Dose de-escalation of adjuvant therapy (DART) in patients with HPV(+)OPSCC was investigated in two prospective Phase II and III clinical trials (MC1273 and MC1675). We report the 30-day morbidity and mortality associated with primary TORS resection in patients enrolled in these trials.

MATERIALS AND METHODS

Patients with HPV(+)OPSCC, who underwent TORS resection between 2013 and 2020 were considered in this analysis. The severity of postoperative transoral bleeding was graded using both the Hinni Grade (HG) transoral surgery bleeding scale and the Common Terminology for Adverse Events (CTCAE) v5.0. Post-surgical complications within 30 days of surgery, as well as rates of tracheostomy, PEG and nasogastric tube placement.

RESULTS

219 patients were included. A total of 7 (3.2 %) patients had a tracheostomy placed at the time of surgery, and all were decannulated within 26 days (median: 5, range: 2-26). There were 33 (15.1 %) returns to the emergency department (ED) with 10 (4.6 %) patients requiring readmission. Using the HG scale, 10 (4.6 %) patients experienced ≥ Grade 3 bleeding with no Grade 5 or 6 bleeds. In contrast, using the CTCAE scale, 15 patients (6.8 %) experienced ≥ Grade 3 bleeding with no Grade 5 bleeds. There was one post-operative death in a patient withdrawn from the trial, and no deaths related to hemorrhage.

CONCLUSION AND RELEVANCE

TORS for HPV(+)OPSCC in carefully selected patients at a high volume center was associated with low morbidity and mortality.

Predicting tumour radiosensitivity to deliver precision radiotherapy

Owing to advances in radiotherapy, the physical properties of radiation can be optimized to enable individualized treatment; however, optimization is rarely based on biological properties and, therefore, treatments are generally planned with the assumption that all tumours respond similarly to radiation. Radiation affects multiple cellular pathways, including DNA damage, hypoxia, proliferation, stem cell phenotype and immune response. In this Review, we summarize the effect of these pathways on tumour responses to radiotherapy and the current state of research on genomic classifiers designed to exploit these variations to inform treatment decisions. We also discuss whether advances in genomics have generated evidence that could be practice changing and whether advances in genomics are now ready to be used to guide the delivery of radiotherapy alone or in combination.

Randomized Phase II Study of Physiologic MRI-Directed Adaptive Radiation Boost in Poor Prognosis Head and Neck Cancer

PURPOSE

We conducted a randomized phase II multicenter clinical trial to test the hypothesis that physiologic MRI-based radiotherapy (RT) dose escalation would improve the outcome of patients with poor prognosis head and neck cancer.

PATIENTS AND METHODS

MRI was acquired at baseline and at RT fraction 10 to create low blood volume/apparent diffusion coefficient maps for RT boost subvolume definition in gross tumor volume. Patients were randomized to receive 70 Gy (standard RT) or 80 Gy to the boost subvolume (RT boost) with concurrent weekly platinum. The primary endpoint was disease-free survival (DFS) with significance defined at a one-sided 0.1 level, and secondary endpoints included locoregional failure (LRF), overall survival (OS), comparison of adverse events and patient reported outcomes (PRO).

RESULTS

Among 81 randomized patients, neither the primary endpoint of DFS (HR = 0.849, P = 0.31) nor OS (HR = 1.19, P = 0.66) was significantly improved in the RT boost arm. However, the incidence of LRF was significantly improved with the addition of the RT boost (HR = 0.43, P = 0.047). Two-year estimates [90% confidence interval (CI)] of the cumulative incidence of LRF were 40% (27%-53%) in the standard RT arm and 18% (10%-31%) in the RT boost arm. Two-year estimates (90% CI) for DFS were 48% (34%-60%) in the standard RT arm and 57% (43%-69%) in the RT boost arm. There were no significant differences in toxicity or longitudinal differences seen in EORTC QLQ30/HN35 subscales between treatment arms in linear mixed-effects models.

CONCLUSIONS

Physiologic MRI-based RT boost decreased LRF without a significant increase in grade 3+ toxicity or longitudinal PRO differences, but did not significantly improve DFS or OS. Additional improvements in systemic therapy are likely necessary to realize improvements in DFS and OS.

Association of Pack-Years of Cigarette Smoking With Survival and Tumor Progression Among Patients Treated With Chemoradiation for Head and Neck Cancer

IMPORTANCE

After 10 pack-years of smoking was initially established as a threshold for risk stratification, subsequent clinical trials incorporated it to identify candidates for treatment deintensification. However, several recent studies were unable to validate this threshold externally, and the threshold for smoking exposure remains unclear.

OBJECTIVE

To estimate the threshold of pack-years of smoking associated with survival and tumor recurrence among patients with head and neck cancer.

DESIGN, SETTING, AND PARTICIPANTS

This single-institution, cohort study included patients with nonmetastatic head and neck cancer receiving chemoradiation from January 2005 to April 2021. Data were analyzed from January to April 2022.

EXPOSURES

Heavy vs light smoking using 22 pack-years as a threshold based on maximizing log-rank test statistic.

MAIN OUTCOMES AND MEASURES

Overall survival (OS), progression-free survival (PFS), locoregional failure (LRF), and distant failure (DF).

RESULTS

A total of 518 patients (427 male [82.4%]; median [IQR] age, 61 [55-66] years) were included. Median (IQR) follow-up was 44.1 (22.3-72.8) months. A nonlinear Cox regression model using restricted cubic splines showed continuous worsening of OS and PFS outcomes as pack-years of smoking increased. The threshold of pack-years to estimate OS and PFS was 22. Cox multivariable analysis (MVA) showed that more than 22 pack-years was associated with worse OS (adjusted hazard ratio [aHR] 1.57; 95% CI, 1.11-2.22; P = .01) and PFS (aHR, 1.38; 95% CI, 1.00-1.89; P = .048). On Fine-Gray MVA, heavy smokers were associated with DF (aHR, 1.71; 95% CI, 1.02-2.88; P = .04), but not LRF (aHR, 1.07; 95% CI, 0.61-1.87; P = .82). When 10 pack-years of smoking were used as a threshold, there was no association for OS (aHR, 1.23; 95% CI, 0.83-1.81; P = .30), PFS (aHR, 1.11; 95% CI, 0.78-1.57; P = .56), LRF (aHR, 1.19; 95% CI, 0.64-2.21; P = .58), and DF (aHR, 1.45; 95% CI, 0.82-2.56; P = .20). Current smoking was associated with worse OS and PFS only among human papillomavirus (HPV)-positive tumors (OS: aHR, 2.81; 95% CI, 1.26-6.29; P = .01; PFS: aHR, 2.51; 95% CI, 1.22-5.14; P = .01).

CONCLUSIONS AND RELEVANCE

In this cohort study of patients treated with definitive chemoradiation, 22 pack-years of smoking was associated with survival and distant metastasis outcomes. Current smoking status was associated with adverse outcomes only among patients with HPV-associated head and neck cancer.

Immune-based classification of HPV-associated oropharyngeal cancer with implications for biomarker-driven treatment de-intensification

BACKGROUND

There is significant interest in treatment de-escalation for human papillomavirus-associated (HPV⁺) oropharyngeal squamous cell carcinoma (OPSCC) patients given the generally favourable prognosis. However, 15-30% of patients recur after primary treatment, reflecting a need for improved risk-stratification tools. We sought to develop a molecular test to risk stratify HPV⁺ OPSCC patients.

METHODS

We created an immune score (UWO3) associated with survival outcomes in six independent cohorts comprising 906 patients, including blinded retrospective and prospective external validations. Two aggressive radiation de-escalation cohorts were used to assess the ability of UWO3 to identify patients who recur. Multivariate Cox models were used to assess the associations between the UWO3 immune class and outcomes.

FINDINGS

A three-gene immune score classified patients into three immune classes (immune rich, mixed, or immune desert) and was strongly associated with disease-free survival in six datasets, including large retrospective and prospective datasets. Pooled analysis demonstrated that the immune rich group had superior disease-free survival compared to the immune desert (HR = 9.0, 95% CI: 3.2-25.5, P = 3.6 × 10^-5) and mixed (HR = 6.4, 95% CI: 2.2-18.7, P = 0.006) groups after adjusting for age, sex, smoking status, and AJCC8 clinical stage. Finally, UWO3 was able to identify patients from two small treatment de-escalation cohorts who remain disease-free after aggressive de-escalation to 30 Gy radiation.

INTERPRETATION

With additional prospective validation, the UWO3 score could enable biomarker-driven clinical decision-making for patients with HPV⁺ OPSCC based on robust outcome prediction across six independent cohorts. Prospective de-escalation and intensification clinical trials are currently being planned.

FUNDING

CIHR, European Union, and the NIH.

Surgical clinical trials for HPV-positive oropharyngeal carcinoma

The treatment of HPV-positive oropharyngeal squamous cell carcinoma (OPSCC) continues to evolve as multiple ongoing and recently completed clinical trials investigate the role of surgery, radiation therapy, chemotherapy, and immunotherapy. Current trials are investigating transoral robotic surgery (TORS) in treatment de-escalation protocols in an effort to optimize quality of life, while maintaining historical survival rates. The advantage of TORS is its minimally invasive approach to primary resection of the tumor as well as valuable pathologic staging. The ORATOR trial reported poorer quality of life in patients treated with TORS compared to primary radiotherapy though this was not a clinically meaningful difference. The recently published ECOG 3311 trial showed that surgery can be used to safely de-escalate the adjuvant radiation dose to 50 Gy in intermediate-risk patients. In this review, we summarize and discuss the past and current clinical trials involving surgery in the treatment of HPV-positive OPSCC.

The optimal 18F-fluoromisonidazole PET threshold to define tumor hypoxia in preclinical squamous cell carcinomas using pO2 electron paramagnetic resonance imaging as reference truth

PURPOSE

To identify the optimal threshold in 18F-fluoromisonidazole (FMISO) PET images to accurately locate tumor hypoxia by using electron paramagnetic resonance imaging (pO2 EPRI) as ground truth for hypoxia, defined by pO2 [Formula: see text] 10 mmHg.

METHODS

Tumor hypoxia images in mouse models of SCCVII squamous cell carcinoma (n = 16) were acquired in a hybrid PET/EPRI imaging system 2 h post-injection of FMISO. T2-weighted MRI was used to delineate tumor and muscle tissue. Dynamic contrast enhanced (DCE) MRI parametric images of Ktrans and ve were generated to model tumor vascular properties. Images from PET/EPR/MRI were co-registered and resampled to isotropic 0.5 mm voxel resolution for analysis. PET images were converted to standardized uptake value (SUV) and tumor-to-muscle ratio (TMR) units. FMISO uptake thresholds were evaluated using receiver operating characteristic (ROC) curve analysis to find the optimal FMISO threshold and unit with maximum overall hypoxia similarity (OHS) with pO2 EPRI, where OHS = 1 shows perfect overlap and OHS = 0 shows no overlap. The means of dice similarity coefficient, normalized Hausdorff distance, and accuracy were used to define the OHS. Monotonic relationships between EPRI/PET/DCE-MRI were evaluated with the Spearman correlation coefficient ([Formula: see text]) to quantify association of vasculature on hypoxia imaged with both FMISO PET and pO2 EPRI.

RESULTS

FMISO PET thresholds to define hypoxia with maximum OHS (both OHS = 0.728 [Formula: see text] 0.2) were SUV [Formula: see text] 1.4 [Formula: see text] SUVmean and SUV [Formula: see text] 0.6 [Formula: see text] SUVmax. Weak-to-moderate correlations (|[Formula: see text]|< 0.70) were observed between PET/EPRI hypoxia images with vascular permeability (Ktrans) or fractional extracellular-extravascular space (ve) from DCE-MRI.

CONCLUSION

This is the first in vivo comparison of FMISO uptake with pO2 EPRI to identify the optimal FMISO threshold to define tumor hypoxia, which may successfully direct hypoxic tumor boosts in patients, thereby enhancing tumor control.

Defining the optimal threshold and prognostic utility of pre-treatment hemoglobin level as a biomarker for survival outcomes in head and neck cancer patients receiving chemoradiation

OBJECTIVES

We sought to define the optimal threshold for anemia in North American head and neck cancer patients and evaluate its role as a prognostic biomarker.

MATERIALS AND METHODS

A single-institution database was queried for patients with head and neck cancer who underwent chemoradiation from January 2005 to April 2021. An optimal threshold of hemoglobin (Hgb) level was defined based on maximum log-rank test statistic. Cox multivariable analysis (MVA), Kaplan-Meier, and propensity score matching were performed to evaluate treatment outcomes.

RESULTS

A total of 496 patients were identified. Threshold for Hgb was determined to be 11.4 for both overall survival (OS) and progression-free survival (PFS). Low Hgb was associated with worse OS (adjusted hazards ratio [aHR] 2.41, 95 % confidence interval [CI] 1.53-3.80, p < 0.001) and PFS (aHR 2.01, 95 % CI 1.30-3.11, p = 0.002). Similar findings were observed among 39 matched pairs for OS (5-year OS 22.3 % vs 49.0 %; HR 2.22, 95 % CI 1.23-4.03, p = 0.008) and PFS (5-year PFS 24.3 % vs 39.1 %; HR 1.78, 95 % CI 1.02-3.12, p = 0.04). Among those with HPV-negative tumors, low Hgb was associated with worse OS (aHR 13.90, 95 % CI 4.66-41.44, p < 0.001) and PFS (aHR 5.24, 95 % CI 2.09-13.18, p < 0.001). However, among those with HPV-positive tumors, low Hgb was not associated with both OS (aHR 1.75, 95 % CI 0.60-5.09, p = 0.31) and PFS (aHR 1.13, 95 % CI 0.41-3.14, p = 0.82).

CONCLUSION AND RELEVANCE

Low Hgb below 11.4 was an independent adverse prognostic factor for worse survival. It was also prognostic among patients with HPV-negative tumors, but not for HPV-positive tumors.

Hypoxia in relationship to tumor volume using hypoxia PET-imaging in head & neck cancer - A scoping review

Background

Hypoxia and large tumor volumes are negative prognostic factors for patients with head and neck squamous cell carcinoma (HNSCC) treated with radiation therapy (RT). PET-scanning with specific hypoxia-tracers (hypoxia-PET) can be used to non-invasively assess hypoxic tumor volume. Primary tumor volume is readily available for patients undergoing RT. However, the relationship between hypoxic volume and primary tumor volume is yet an open question. The current study investigates the hypotheses that larger tumors contain both a larger hypoxic volume and a higher hypoxic fraction.

Methods

PubMed and Embase were systematically searched to identify articles fulfilling the predefined criteria. Individual tumor data (primary tumor volume and hypoxic volume/fraction) was extracted. Relationship between hypoxic volume and primary tumor volume was investigated by linear regression. The correlation between hypoxic fraction and log2(primary tumor volume) was determined for each cohort and in a pooled analysis individual regression slopes and coefficients of determination (R2) were weighted according to cohort size.

Results

21 relevant articles were identified and individual data from 367 patients was extracted, out of which 323 patients from 17 studies had quantifiable volumes of interest. A correlation between primary tumor volume and PET-determined hypoxic volume was found (P <.001, R2 = 0.46). Larger tumors had a significantly higher fraction of hypoxia compared with smaller tumors (P<.01). The weighted analysis of all studies revealed that for each doubling of the tumor volume, the hypoxic fraction increased by four percentage points.

Conclusion

This study shows correlations between primary tumor volume and hypoxic volume as well as primary tumor volume and the hypoxic fraction in patients with HNSCC. The findings suggest that not only do large tumors contain more cancer cells, they also have a higher proportion of potentially radioresistant hypoxic cells. This knowledge can be important when individualizing RT.

Pretreatment Lymphocyte Count Predicts Benefit From Concurrent Chemotherapy With Radiotherapy in Oropharyngeal Cancer

PURPOSE

There is a need to refine the selection of patients with oropharyngeal squamous cell carcinoma (OPSCC) for treatment de-escalation. We investigated whether pretreatment absolute lymphocyte count (ALC) predicted overall survival (OS) benefit from the addition of concurrent chemotherapy to radical radiotherapy.

PATIENTS AND METHODS

This was an observational study of consecutive OPSCCs treated by curative-intent radiotherapy, with or without concurrent chemotherapy (n = 791) with external, independent validation from a separate institution (n = 609). The primary end point was OS at 5 years. Locoregional control (LRC) was assessed using competing risk regression as a secondary end point. Previously determined prognostic factors were used in a multivariable Cox proportional hazards model to assess the prognostic importance of ALC and the interaction between ALC and cisplatin chemotherapy use.

RESULTS

Pretreatment ALC was prognostic for 5-year OS on multivariable analysis (hazard ratio [HR] 0.64; 95% CI, 0.42 to 0.98; P = .04). It also predicted benefit from the use of concurrent cisplatin chemotherapy, with a significant interaction between cisplatin chemotherapy and pretreatment ALC (likelihood ratio test, P = .04): higher ALC count reduced the 5-year OS benefit compared with radiotherapy alone (HR 2.53; 95% CI, 1.03 to 6.19; P = .043). This was likely driven by an effect on LRC up to 5 years (interaction subdistribution HR 2.29; 95% CI, 0.68 to 7.71; P = .094). An independent validation cohort replicated the OS (HR 2.53; 95% CI, 0.98 to 6.52; P = .055) and LRC findings (interaction subdistribution HR 3.43; 95% CI, 1.23 to 9.52; P = .018).

CONCLUSION

For OPSCC, the pretreatment ALC is prognostic for OS and also predicts benefit from the addition of cisplatin chemotherapy to radiotherapy. These findings require prospective evaluation, and could inform the selection of good prognosis patients for a de-escalation trial.

Cell-free human papillomavirus DNA kinetics after surgery for human papillomavirus-associated oropharyngeal cancer

BACKGROUND

New ultrasensitive methods for detecting residual disease after surgery are needed in human papillomavirus-associated oropharyngeal squamous cell carcinoma (HPV+OPSCC).

METHODS

To determine whether the clearance kinetics of circulating tumor human papillomavirus DNA (ctHPVDNA) is associated with postoperative disease status, a prospective observational study was conducted in 33 patients with HPV+OPSCC undergoing surgery. Blood was collected before surgery, postoperative days 1 (POD 1), 7, and 30 and with follow-up. A subcohort of 12 patients underwent frequent blood collections in the first 24 hours after surgery to define early clearance kinetics. Plasma was run on custom droplet digital polymerase chain reaction (ddPCR) assays for HPV genotypes 16, 18, 33, 35, and 45.

RESULTS

In patients without pathologic risk factors for recurrence who were observed after surgery, ctHPVDNA rapidly decreased to <1 copy/mL by POD 1 (n = 8/8). In patients with risk factors for macroscopic residual disease, ctHPVDNA was markedly elevated on POD 1 (>350 copies/mL) and remained elevated until adjuvant treatment (n = 3/3). Patients with intermediate POD 1 ctHPVDNA levels (1.2-58.4 copies/mL) all possessed pathologic risk factors for microscopic residual disease (n = 9/9). POD 1 ctHPVDNA levels were higher in patients with known adverse pathologic risk factors such as extranodal extension >1 mm (P = .0481) and with increasing lymph nodes involved (P = .0453) and were further associated with adjuvant treatment received (P = .0076). One of 33 patients had a recurrence that was detected by ctHPVDNA 2 months earlier than clinical detection.

CONCLUSIONS

POD 1 ctHPVDNA levels are associated with the risk of residual disease in patients with HPV+OPSCC undergoing curative intent surgery and thus could be used as a personalized biomarker for selecting adjuvant treatment in the future.

LAY SUMMARY

Human papillomavirus-associated oropharyngeal squamous cell carcinoma (HPV+OPSCC) is increasing at epidemic proportions and is commonly treated with surgery. This report describes results from a study examining the clearance kinetics of circulating tumor HPV DNA (circulating tumor human papillomavirus DNA [ctHPVDNA]) following surgical treatment of HPV+OPSCC. We found that ctHPVDNA levels 1 day after surgery are associated with the risk of residual disease in patients with HPV+OPSCC and thus could be used as a personalized biomarker for selecting adjuvant treatment in the future. These findings are the first to demonstrate the potential utility of ctHPVDNA in patients with HPV+OPSCC undergoing surgery.

De-Escalation Strategies for Human Papillomavirus-Associated Oropharyngeal Squamous Cell Carcinoma—Where Are We Now?

The prevalence of oropharyngeal squamous cell carcinoma has been increasing in North America due to human papillomavirus-associated disease. It is molecularly distinct and differs from other head and neck cancers due to the young population and high survival rate. The treatment regimens currently in place cause significant long-term toxicities. Studies have transitioned from mortality-based outcomes to patient-reported outcomes assessing quality of life. There are many completed and ongoing trials investigating alternative therapy regimens or de-escalation strategies to minimize the negative secondary effects while maintaining overall survival and disease-free survival. The goal of this review is to discuss the most recent advancements within the field while summarizing and reviewing the available evidence.

Disadvantaged Subgroups Within the Global Head and Neck Cancer Population: How Can We Optimize Care?

Within the global head and neck cancer population, there are subgroups of patients with poorer cancer outcomes independent from tumor characteristics. In this article, we review three such groups. The first group comprises patients with nasopharyngeal cancer in low- and middle-income countries where access to high-volume, well-resourced radiotherapy centers is limited. We discuss a recent study that is aiming to improve outcomes through the instigation of a comprehensive radiotherapy quality assurance program. The second group comprises patients with low socioeconomic status in a high-income country who experience substantial financial toxicity, defined as financial hardship for patients due to health care costs. We review causes and consequences of financial toxicity and discuss how it can be mitigated. The third group comprises older patients who may poorly tolerate and not benefit from intensive standard-of-care treatment. We discuss the role of geriatric assessment, particularly in relation to the use of chemotherapy. Through better recognition and understanding of disadvantaged groups within the global head and neck cancer population, we will be better placed to instigate the necessary changes to improve outcomes and quality of life for patients with head and neck cancer.

Human papillomavirus-related oropharyngeal carcinoma

It was not until around 2000 that human papillomavirus-related oropharyngeal carcinoma was recognized as carcinoma with clinical presentations different from nonrelated head and neck carcinoma. Twenty years after and with the revision of the tumor-node-metastasis classification in 2017, various clinical trials focused on human papillomavirus-related oropharyngeal carcinoma to improve the prognosis and quality of life of patients with this disease. However, the incidence of human papillomavirus-related cancers is increasing, which is expected to be particularly prominent in Japan, where human papillomavirus vaccination is not widely available. In this review, we describe the current status of clinical trials (mainly focused on initial surgery and radiation dose reduction) for, primary and secondary prevention of, and the present status of human papillomavirus-related oropharyngeal carcinoma in Japan.

The impact of head and neck radiotherapy on salivary flow and quality of life: Results of the ORARAD study

OBJECTIVES

Salivary hypofunction and xerostomia, are common side effects of radiotherapy, negatively impacting quality of life. The OraRad study presents results on the longitudinal impact of radiotherapy on salivary flow and patient-reported outcomes.

PATIENTS AND METHODS

Prospective, multicenter cohort study of 572 patients receiving curative-intent head and neck radiotherapy (RT). Stimulated salivary flow (SSF) rate and patient-reported outcomes were measured prior to RT and at 6- and 18-months post-RT. Linear mixed effects models examined the relationship between RT dose and change in salivary flow, and change in patient-reported outcomes.

RESULTS

544 patients had baseline salivary flow measurement, with median (IQR) stimulated flow rate of 0.975 (0.648, 1.417) g/min. Average RT dose to parotid glands was associated with change in salivary flow post-RT (p < 0.001). Diminished flow to 37% of pre-RT level was observed at 6 months (median: 0.358, IQR: 0.188 to 0.640 g/min, n = 481) with partial recovery to 59% of pre-RT at 18 months (median: 0.575, IQR: 0.338 to 0.884 g/min, n = 422). Significant improvement in patient-reported swallowing, senses (taste and smell), mouth opening, dry mouth, and sticky saliva (p-values < 0.03) were observed between 6 and 18 months post-RT. Changes in swallowing, mouth opening, dry mouth, and sticky saliva were significantly associated with changes in salivary flow from baseline (p-values < 0.04).

CONCLUSION

Salivary flow and patient-reported outcomes decreased as a result of RT, but demonstrated partial recovery during follow-up. Continued efforts are needed to improve post-RT salivary function to support quality of life.

Evaluation of Substantial Reduction in Elective Radiotherapy Dose and Field in Patients With Human Papillomavirus-Associated Oropharyngeal Carcinoma Treated With Definitive Chemoradiotherapy

IMPORTANCE

Several de-escalation strategies for human papillomavirus (HPV)-associated oropharyngeal carcinoma (OPC) have focused on deintensifying gross disease treatment. Reduction of radiotherapy dose and target volume to subclinical regions may achieve good clinical outcomes with favorable patient quality of life (QOL).

OBJECTIVE

To determine outcomes from a systematic approach of reducing radiotherapy dose and target volume to the elective treatment regions in patients with HPV-associated OPC undergoing concurrent chemoradiotherapy (CCRT).

DESIGN, SETTING, AND PARTICIPANTS

This retrospective cohort study included 276 consecutive patients with HPV-positive OPC receiving CCRT from March 1, 2017, to July 31, 2019. Data were analyzed from February 23 to September 13, 2021.

INTERVENTIONS

Elective nodal and subclinical regions received 30 Gy of radiotherapy in 15 fractions, followed by a cone down of 40 Gy in 20 fractions to gross disease for a total dose of 70 Gy. The high retropharyngeal nodal basins in the node-negative neck and bilateral levels IB and V basins were omitted.

MAIN OUTCOMES AND MEASURES

Patients were followed up to evaluate locoregional control as the primary outcome and distant metastasis-free survival, progression-free survival, and overall survival as secondary outcomes. Quality-of-life data were obtained at each visit when feasible.

RESULTS

Among the 276 patients included in the analysis, the median age was 61 (range, 36-87) years; 247 (89.5%) were men; and 183 (66.3%) had less than 10 pack-years of smoking history. Most patients (251 [90.9%]) were White. Overall, 87 (31.5%) had cT3-cT4 disease and 65 (23.5%) had cN2-cN3 disease per the 8th edition of the American Joint Committee on Cancer Staging Manual. One hundred seventy-two patients (62.3%) completed 300-mg/m2 high-dose cisplatin therapy. During a median follow-up of 26 (range, 21-32) months, 8 patients developed locoregional recurrence, including 7 at the primary site or gross nodes that received a total dose of 70 Gy and 1 with a persistent node not previously identified as gross disease that received a total dose of only 30 Gy. The 24-month locoregional control was 97.0%; progression-free survival, 88.0%; distant metastasis-free survival, 95.2%; and overall survival, 95.1%. During treatment, 17 patients (6.2%) required a feeding tube. At 24 months, most of the QOL composite scores (jaw-related problems, pain, social contact, eating, speech, and swallow) were comparable or superior to baseline measures except for senses, dry mouth, muscular tension, and cognitive functioning, which improved over time but remained marginally worse than baseline.

CONCLUSIONS AND RELEVANCE

This cohort study found that the evaluated de-escalation strategy for elective regions showed favorable clinical outcomes and QOL profiles. Long-term follow-up data will help affirm the efficacy of this strategy as a care option for treating HPV-associated OPC with primary CCRT.

The value of plasma hypoxia markers for predicting imaging-based hypoxia in patients with head-and-neck cancers undergoing definitive chemoradiation

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Higher osteopontin plasma levels correlate with more hypoxic tumors at baseline.

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Increased baseline osteopontin levels are associated with residual tumor hypoxia.

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Absent early hypoxia response is linked with higher VEGF and CTGF levels in week 5.

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Plasma hypoxic markers may serve as biomarkers favoring radiotherapy personalization.

Background

Methods

Results

Conclusion

Prospective study evaluating dynamic changes of cell-free HPV DNA in locoregional viral-associated oropharyngeal cancer treated with induction chemotherapy and response-adaptive treatment

BACKGROUND

Human papillomavirus (HPV)-associated oropharyngeal cancer (OPC) has a favorable prognosis which has led to efforts to de-intensify treatment. Response-adaptive de-escalated treatment is promising, however improved biomarkers are needed. Quantitative cell-free HPV-DNA (cfHPV-DNA) in plasma represents an attractive non-invasive biomarker for grading treatment response and post-treatment surveillance. This prospective study evaluates dynamic changes in cfHPV-DNA during induction therapy, definitive (chemo)radiotherapy, and post-treatment surveillance in the context of risk and response-adaptive treatment for HPV + OPC.

METHODS

Patients with locoregional HPV + OPC are stratified into two cohorts: High risk (HR) (T4, N3, [Formula: see text] 20 pack-year smoking history (PYH), or non-HPV16 subtype); Low risk (LR) (all other patients). All patients receive induction chemotherapy with three cycles of carboplatin and paclitaxel. LR with ≥ 50% response receive treatment on the single-modality arm (minimally-invasive surgery or radiation alone to 50 Gy). HR with ≥ 50% response or LR with ≥ 30% and < 50% response receive treatment on the intermediate de-escalation arm (chemoradiation to 50 Gy with cisplatin). All other patients receive treatment on the regular dose arm with chemoradiation to 70 Gy with concurrent cisplatin. Plasma cfHPV-DNA is assessed during induction, (chemo)radiation, and post-treatment surveillance. The primary endpoint is correlation of quantitative cfHPV-DNA with radiographic response.

DISCUSSION

A de-escalation treatment paradigm that reduces toxicity without compromising survival outcomes is urgently needed for HPV + OPC. Response to induction chemotherapy is predictive and prognostic and can select candidates for de-escalated definitive therapy. Assessment of quantitative cfHPV-DNA in the context of response-adaptive treatment of represents a promising reliable and convenient biomarker-driven strategy to guide personalized treatment in HPV + OPC.

TRIAL REGISTRATION

This trial is registered with ClinicalTrials.gov on October 1st, 2020 with Identifier: NCT04572100 .

Induction Chemotherapy in Low-Risk HPV+ Oropharyngeal Cancer

OPINION STATEMENT

Human papillomavirus (HPV) associated oropharyngeal squamous cell carcinoma (OPSCC) is rapidly increasing in incidence, and has now become the most common head and neck cancer (HNC). Studies have demonstrated that HPV associated OPSCC is associated with a favorable prognosis compared with its HPV-negative counterparts, yet standard multimodality therapy is often associated with substantial acute and late treatment-related toxicity. While locoregional control is improved in HPV+ OPSCC, distant metastasis rate has gained recognition as a major cause of death in this population, with some studies suggesting similar rates as non-HPV-related cancers. Induction chemotherapy has been of long-standing interest in locoregionally advanced HNC, yet its use in combination with concomitant chemoradiation remains an area of controversy as a survival benefit remains unproven following randomized trials. Nevertheless, response to induction chemotherapy remains an important dynamic and prognostic biomarker, with response-adaptive de-intensified therapy in HPV+ OPSCC gaining traction in single-arm phase II studies demonstrating promising results. The emergence of immunotherapy in the recurrent/metastatic setting for HNC has led to enthusiasm to incorporate in the curative setting, yet its role remains undefined. Our institutional paradigm for HPV+ OPSCC incorporates induction therapy followed by risk and response adaptive locoregional treatment. Ultimately, the role of induction therapy in HPV+ OPSCC will need to be investigated in a randomized setting to be incorporated routinely into clinical practice.

Cell free HPV DNA provides an accurate and rapid diagnosis of HPV-associated head and neck cancer

PURPOSE

HPV-associated Head and Neck Squamous Cell Carcinoma(HPV+HNSCC) is the most common HPV-associated malignancy in the United States and continues to increase in incidence. Current diagnostic approaches for HPV+HNSCC rely on tissue biopsy followed by histomorphologic assessment and detection of HPV indirectly by p16 immunohistochemistry. Such approaches are invasive and have variable sensitivity.

EXPERIMENTAL DESIGN

We conducted a prospective observational study in 140 subjects (70 cases and 70 controls) to test the hypothesis that a non-invasive diagnostic approach for HPV+HNSCC would have improved diagnostic accuracy, lower cost, and shorter Diagnostic Interval compared to standard approaches. Blood was collected, processed for circulating tumor HPV DNA(ctHPVDNA) and analyzed with custom ddPCR assays for HPV genotypes 16,18, 33, 35 and 45. Diagnostic performance, cost and Diagnostic Interval were calculated for standard clinical work up and compared to a non-invasive approach using ctHPVDNA combined with cross-sectional imaging and physical exam findings.

RESULTS

Sensitivity and specificity of ctHPVDNA for detecting HPV+HNSCC was 98.4% and 98.6%. Sensitivity and specificity of a composite non-invasive diagnostic using ctHPVDNA and imaging/physical exam were 95.1% and 98.6%. Diagnostic accuracy of this non-invasive approach was significantly higher than standard of care (Youden index 0.937 vs 0.707, p=0.0006). Costs of non-invasive diagnostic were 36-38% less than standard clinical work up and the median Diagnostic Interval was 26 days less.

CONCLUSIONS

A non-invasive diagnostic approach for HPV+HNSCC demonstrated improved accuracy, reduced cost and a shorter time to diagnosis compared to standard clinical workup and could be a viable alternative in the future.

Radiomics Predicts for Distant Metastasis in Locally Advanced Human Papillomavirus-Positive Oropharyngeal Squamous Cell Carcinoma

Simple Summary

There is strong evidence that locally advanced human papillomavirus positive (HPV+) oropharyngeal squamous cell carcinoma (OPSCC) carries a significantly better prognosis than HPV negative OPSCC, suggesting the possibility of treatment de-escalation and, therefore, toxicity reduction in this patient population. The lack of success in clinical trials towards this end presses the need to risk stratify locally advanced HPV+ OPSCC patients who can safely have treatment de-escalated. The present study had recourse to radiomics for this purpose and showed that radiomics has the ability to discriminate patients with locally advanced HPV+ OPSCC who went on to develop distant metastasis after completion of definitive chemoradiation or radiation alone. The implications of this study aid in demonstrating the potential pivotal role of radiomics in predictive risk assessment and personalizing therapy for this patient population.

Abstract

(1) Background and purpose: clinical trials have unsuccessfully tried to de-escalate treatment in locally advanced human papillomavirus positive (HPV+) oropharyngeal squamous cell carcinoma (OPSCC) with the goal of reducing treatment toxicity. The aim of this study was to explore the role of radiomics for risk stratification in this patient population to guide treatment. (2) Methods: the study population consisted of 225 patients with locally advanced HPV+ OPSCC treated with curative-intent radiation or chemoradiation therapy. Appearance of distant metastasis was used as the endpoint event. Radiomics data were extracted from the gross tumor volumes (GTVs) identified on the planning CT, with gray level being discretized using three different bin widths (8, 16, and 32). The data extracted for the groups with and without distant metastasis were subsequently balanced using three different algorithms including synthetic minority over-sampling technique (SMOTE), adaptive synthetic sampling (ADASYN), and borderline SMOTE. From these different combinations, a total of nine radiomics datasets were derived. Top features that minimized redundancy while maximizing relevance to the endpoint were selected individually and collectively for the nine radiomics datasets to build support vector machine (SVM) based predictive classifiers. Performance of the developed classifiers was evaluated by receiver operating characteristic (ROC) curve analysis. (3) Results: of the 225 locally advanced HPV+ OPSCC patients being studied, 9.3% had developed distant metastases at last follow-up. SVM classifiers built for the nine radiomics dataset using either their own respective top features or the top consensus ones were all able to differentiate the two cohorts at a level of excellence or beyond, with ROC area under curve (AUC) ranging from 0.84 to 0.95 (median = 0.90). ROC comparisons further revealed that the majority of the built classifiers did not distinguish the two cohorts significantly better than each other. (4) Conclusions: radiomics demonstrated discriminative ability in distinguishing patients with locally advanced HPV+ OPSCC who went on to develop distant metastasis after completion of definitive chemoradiation or radiation alone and may serve to risk stratify this patient population with the purpose of guiding the appropriate therapy.

Interleukin-6 as surrogate marker for imaging-based hypoxia dynamics in patients with head-and-neck cancers undergoing definitive chemoradiation-results from a prospective pilot trial

Purpose

Intratumoral hypoxia increases resistance of head-and-neck squamous cell carcinoma (HNSCC) to radiotherapy. [¹⁸F]FMISO PET imaging enables noninvasive hypoxia monitoring, though requiring complex logistical efforts. We investigated the role of plasma interleukin-6 (IL-6) as potential surrogate parameter for intratumoral hypoxia in HNSCC using [¹⁸F]FMISO PET/CT as reference.

Methods

Within a prospective trial, serial blood samples of 27 HNSCC patients undergoing definitive chemoradiation were collected to analyze plasma IL-6 levels. Intratumoral hypoxia was assessed in treatment weeks 0, 2, and 5 using [¹⁸F]FMISO PET/CT imaging. The association between PET-based hypoxia and IL-6 was examined using Pearson’s correlation and multiple regression analyses, and the diagnostic power of IL-6 for tumor hypoxia response prediction was determined with receiver-operating characteristic analyses.

Results

Mean IL-6 concentrations were 15.1, 19.6, and 31.0 pg/mL at baseline, week 2 and week 5, respectively. Smoking (p=0.050) and reduced performance status (p=0.011) resulted in higher IL-6 levels, whereas tumor (p=0.427) and nodal stages (p=0.334), tumor localization (p=0.439), and HPV status (p=0.294) had no influence. IL-6 levels strongly correlated with the intratumoral hypoxic subvolume during treatment (baseline: r=0.775, p<0.001; week 2: r=0.553, p=0.007; week 5: r=0.734, p<0.001). IL-6 levels in week 2 were higher in patients with absent early tumor hypoxia response (p=0.016) and predicted early hypoxia response (AUC=0.822, p=0.031). Increased IL-6 levels at week 5 resulted in a trend towards reduced progression-free survival (p=0.078) and overall survival (p=0.013).

Conclusion

Plasma IL-6 is a promising surrogate marker for tumor hypoxia dynamics in HNSCC patients and may facilitate hypoxia-directed personalized radiotherapy concepts.

Trial registration

The prospective trial was registered in the German Clinical Trial Register (DRKS00003830). Registered 20 August 2015

Supplementary Information

The online version contains supplementary material available at 10.1007/s00259-021-05602-x.

Dynamics-Adapted Radiotherapy Dose (DARD) for Head and Neck Cancer Radiotherapy Dose Personalization

Standard of care radiotherapy (RT) doses have been developed as a one-size-fits all approach designed to maximize tumor control rates across a population. Although this has led to high control rates for head and neck cancer with 66-70 Gy, this is done without considering patient heterogeneity. We present a framework to estimate a personalized RT dose for individual patients, based on pre- and early on-treatment tumor volume dynamics-a dynamics-adapted radiotherapy dose (D_DARD). We also present the results of an in silico trial of this dose personalization using retrospective data from a combined cohort of n = 39 head and neck cancer patients from the Moffitt and MD Anderson Cancer Centers that received 66-70 Gy RT in 2-2.12 Gy weekday fractions. This trial was repeated constraining D_DARD between (54, 82) Gy to test more moderate dose adjustment. D_DARD was estimated to range from 8 to 186 Gy, and our in silico trial estimated that 77% of patients treated with standard of care were overdosed by an average dose of 39 Gy, and 23% underdosed by an average dose of 32 Gy. The in silico trial with constrained dose adjustment estimated that locoregional control could be improved by >10%. We demonstrated the feasibility of using early treatment tumor volume dynamics to inform dose personalization and stratification for dose escalation and de-escalation. These results demonstrate the potential to both de-escalate most patients, while still improving population-level control rates.

Therapeutic strategies for systemic therapies of human papillomavirus-related oropharyngeal cancer

Our understanding of human papillomavirus (HPV)-related oropharyngeal cancer (OPC) and its molecular basis continues to evolve and produce important insights into customized therapeutic strategies. Novel therapeutics exploiting HPV-related targets are being evaluated in the incurable setting, while the favorable prognosis of locoregionally advanced disease has stimulated investigation into de-escalation strategies. There is much opportunity for better personalization of standard therapy according to HPV status. This review discusses both current and investigational therapeutic strategies for HPV-related OPC.

Volumetric staging in radiotherapy for oropharyngeal cancers

INTRODUCTION

Despite routine use of 3D radiotherapy planning in radical radio(chemo)therapy for oropharyngeal cancers, volumetric data have not been implemented in initial staging. We analyzed 228 oropharyngeal cancer cases treated at one institution between 2004 and 2014 to compare the predictive value of volumetric staging and tumor nodal metastasis staging system (TNM) and determine whether they could be complementary for the estimation of survival.

METHODS

This retrospective study analyzed 228 consecutive oropharyngeal cancer cases treated with radiotherapy (76.9%) or concurrent radiochemotherapy (23.1%) between 2004 and 2014. The volumetric parameters included primary gross tumor volume (pGTV), metastatic lymph nodes gross tumor volume (nGTV), and total gross tumor volume (tGTV), and were compared with the 7th edition of the TNM staging system.

RESULTS

Median overall survival (OS) was 30.3 months. In the receiver operating characteristic analysis, tGTV had the highest area under the curve (AUC) of 0.66, followed by pGTV (AUC,0.64), nGTV (AUC 0.62), and TNM (AUC 0.6). The median OS for patients with tGTV ⩽32.2 mL was 40.5 months, compared to 15.4 months for >32.2 mL (p < 0.001). This threshold allowed for a statistically significant difference in survival between TNM stage IV cases with low and high tumor volume (p < 0.001). Despite both TNM and tGTV reaching statistical significance in univariate analysis, only the tGTV remained an independent prognostic factor in the multivariate analysis (hazard ratio 1.07, confidence interval 1.02-1.12, p = 0.008).

CONCLUSIONS

tGTV is an independent prognostic factor, characterized by a higher discriminatory value than the TNM staging system, and can be used to further divide stage IV cases into subgroups with significantly different prognosis.

Current considerations for radiotherapy in HPV-associated head and neck cancer

Human papillomavirus (HPV)-mediated oncogenesis confers increased sensitivity to radiotherapy and HPV head and neck cancer is associated with improved patient outcomes. As such, management of HPV-related head and neck cancer requires a multidisciplinary approach that balances maximizing locoregional control with minimizing treatment-related toxicity. We highlight considerations in radiation dose and target delineation, as well as considerations for chemoradiation, postoperative radiotherapy, and single modality, definitive radiotherapy.

Genomic Signatures in HPV-Associated Tumors

Papillomaviruses dysregulate the G1/S cell cycle transition in order to promote DNA synthesis in S phase, which is a requirement for viral replication. The human papillomaviruses (HPV) E6 and E7 oncoproteins mediate degradation of the cell cycle regulators p53 and Rb, which are two of the most universally disrupted tumor-suppressor genes in all of cancer. The G1/S checkpoint is activated in normal cells to allow sufficient time for DNA repair in G1 before proceeding to replicate DNA and risk propagating unrepaired errors. The TP53 pathway suppresses a variety of such errors, including translocation, copy number alterations, and aneuploidy, which are thus found in HPV-associated tumors similarly to HPV-negative tumors with other mechanisms of TP53 disruption. However, E6 and E7 maintain a variety of other virus–host interactions that directly disrupt a growing list of other DNA repair and chromatin remodeling factors, implying HPV-specific repair deficiencies. In addition, HPV-associated squamous cell carcinomas tumors clinically respond differently to DNA damaging agents compared to their HPV negative counterparts. The focus of this review is to integrate three categories of observations: (1) pre-clinical understanding as to the effect of HPV on DNA repair, (2) genomic signatures of DNA repair in HPV-associated tumor genomes, and (3) clinical responses of HPV-associated tumors to DNA damaging agents. The goals are to try to explain why HPV-associated tumors respond so well to DNA damaging agents, identify missing pieces, and suggest clinical strategies could be used to further improve treatment of these cancers.

HPV-associated oropharyngeal cancer de-escalation strategies and trials: Past failures and future promise

HPV-associated oropharynx squamous cell carcinomas are radiosensitive and chemosensitive, thus, portending a favorable prognosis. Treatment de-intensification strategies aim to reduce toxicity while maintaining efficacy. Although approaches that have substituted cisplatin with cetuximab or omitted chemotherapy have not been successful, Transoral Robotic Surgery with de-intensified adjuvant therapy has been promising. Additionally, personalized approaches are taking advantage of tumor biology and utilizing tumor reduction or hypoxia on imaging as a predictive marker to successfully de-escalate radiotherapy and chemotherapy.

The effect of short radiation treatment breaks on chemo-radiotherapy for oropharyngeal cancers

BACKGROUND

Numerous studies and guidelines suggest an outcome detriment from radiation treatment breaks (rTBs) and the need for compensatory dosing in patients with head and neck cancer.

METHODS

In a consecutive cohort of 521 patients with oropharyngeal squamous cell carcinoma (OPSCC), we investigated the impact of rTBs and prolongation of overall treatment time (OTT) on OS, DFS, LRC, and cancer recurrence using competing risk and multivariate analyses.

RESULTS

Neither OTT prolongation by ≤2 days nor rTBs of ≤3 days were associated with detriments to clinical outcomes. Consecutive breaks of ≥3 days were also not significantly associated with detriment to clinical outcomes. There was significantly increased competing mortality in those with longer breaks.

CONCLUSIONS

In OPSCC patients treated with definitive concurrent chemoradiotherapy, there is no significant association between disease failure and total rTBs of ≤3 consecutive or scattered days. Further investigation is needed for longer breaks.

Defining the Role of Immunotherapy in the Curative Treatment of Locoregionally Advanced Head and Neck Cancer: Promises, Challenges, and Opportunities

Recent advancements in the development of immunotherapies have raised the hope for patients with locally-advanced HNSCC (LA-HNSCC) to achieve improved oncologic outcomes without the heavy burden of treatment-related morbidity. While there are several ongoing late phase clinical trials that seek to determine whether immunotherapy can be effectively employed in the definitive setting, initial results from concurrent immuno-radiotherapy therapy trials have not shown strong evidence of benefit. Encouragingly, evidence from preclinical studies and early-phase neoadjuvant studies have begun to show potential pathways forward, with therapeutic combinations and sequences that intentionally spare tumor draining lymphatics in order to maximize the synergy between definitive local therapy and immunotherapy. The intent of this review is to summarize the scientific rationale and current clinical evidence for employing immunotherapy for LA-HNSCC as well as the ongoing efforts and challenges to determine how to optimally deliver and sequence immunotherapy alongside traditional therapeutics. In both the preclinical and clinical settings, we will discuss the application of immunotherapies to both surgical and radiotherapeutic management of HNSCC.

Role of MRI-Based Functional Imaging in Improving the Therapeutic Index of Radiotherapy in Cancer Treatment

Advances in radiation technology, such as intensity-modulated radiation therapy (IMRT), have largely enabled a biological dose escalation of the target volume (TV) and reduce the dose to adjacent tissues or organs at risk (OARs). However, the risk of radiation-induced injury increases as more radiation dose utilized during radiation therapy (RT), which predominantly limits further increases in TV dose distribution and reduces the local control rate. Thus, the accurate target delineation is crucial. Recently, technological improvements for precise target delineation have obtained more attention in the field of RT. The addition of functional imaging to RT can provide a more accurate anatomy of the tumor and normal tissues (such as location and size), along with biological information that aids to optimize the therapeutic index (TI) of RT. In this review, we discuss the application of some common MRI-based functional imaging techniques in clinical practice. In addition, we summarize the main challenges and prospects of these imaging technologies, expecting more inspiring developments and more productive research paths in the near future.

Radiation Treatment Deintensification for HPV-Associated Oropharyngeal Cancer

Human papillomavirus-associated oropharyngeal cancer (HPV-OPC) is a distinct clinical entity with a favorable prognosis compared with non-HPV-OPC. Surgery and radiotherapy (RT) result in adverse effects, and negative quality of life or functional outcomes, which impact a significant proportion of HPV-OPC survivors. Ongoing studies aim to reduce these negative treatment effects while maintaining high cure rates through deintensified therapy typically use either a primary surgical or RT approach. A single-day curative surgery will remain relevant for many patients with early-stage disease. However, the average patient with HPV-OPC will have indications for adjuvant therapy. A primary RT approach to deintensified therapy has more available data from patients on prospective multi-institutional trials, provides broader patient selection, and may be more cost-effective. Anticipated results from an active phase II/III NCTN trial will help guide the standard of care using primary RT. Next generation trials will help further refine patient selection and/or radical deintensification (30-50 Gy).

Treatment De-intensification for HPV-associated Oropharyngeal Cancer: A Definitive Surgery Paradigm

Human papillomavirus-associated oropharyngeal squamous cell carcinoma (HPV+OPSCC) constitutes the majority of head and neck diagnoses within the United States. Patients with HPV+OPSCC have biologically and demographically distinct disease, leading to high cure rates after standard treatments. This long survivorship period coupled with the toxicity of standard treatments makes de-intensification strategies an urgent research question. Surgery has generally been avoided for HPV+OPSCC as historical surgical techniques were invasive and morbid. With the advent of minimally invasive transoral techniques, definitive surgical options are becoming more popular. Minimally invasive surgery offers unique opportunities in a de-intensification paradigm, including more detailed patient selection, radiation volume reduction, and radiation dose de-intensification. Nevertheless, careful patient selection must be exercised as surgical defects may lead to quality of life decrements beyond what is gained through de-intensification. Ongoing phase III efforts will help clarify the patient cohorts best suited for surgically oriented de-intensification.

Advances in Imaging for HPV-Related Oropharyngeal Cancer: Applications to Radiation Oncology

While there has been an overall decline of tobacco and alcohol-related head and neck cancer in recent decades, there has been an increased incidence of HPV-associated oropharyngeal cancer (OPC). Recent research studies and clinical trials have revealed that the cancer biology and clinical progression of HPV-positive OPC is unique relative to its HPV-negative counterparts. HPV-positive OPC is associated with higher rates of disease control following definitive treatment when compared to HPV-negative OPC. Thus, these conditions should be considered unique diseases with regards to treatment strategies and survival. In order to sufficiently characterize HPV-positive OPC and guide treatment strategies, there has been a considerable effort to diagnose, prognose, and track the treatment response of HPV-associated OPC through advanced imaging research. Furthermore, HPV-positive OPC patients are prime candidates for radiation de-escalation protocols, which will ideally reduce toxicities associated with radiation therapy and has prompted additional imaging research to detect radiation-induced changes in organs at risk. This manuscript reviews the various imaging modalities and current strategies for tackling these challenges as well as provides commentary on the potential successes and suggested improvements for the optimal treatment of these tumors.

Application of Community Detection Algorithm to Investigate the Correlation between Imaging Biomarkers of Tumor Metabolism, Hypoxia, Cellularity, and Perfusion for Precision Radiotherapy in Head and Neck Squamous Cell Carcinomas

The present study aimed to investigate the correlation at pre-treatment (TX) between quantitative metrics derived from multimodality imaging (MMI), including 18F-FDG-PET/CT, 18F-FMISO-PET/CT, DW- and DCE-MRI, using a community detection algorithm (CDA) in head and neck squamous cell carcinoma (HNSCC) patients. Twenty-three HNSCC patients with 27 metastatic lymph nodes underwent a total of 69 MMI exams at pre-TX. Correlations among quantitative metrics derived from FDG-PET/CT (SUL), FMSIO-PET/CT (K1, k3, TBR, and DV), DW-MRI (ADC, IVIM [D, D*, and f]), and FXR DCE-MRI [Ktrans, ve, and τi]) were investigated using the CDA based on a "spin-glass model" coupled with the Spearman's rank, ρ, analysis. Mean MRI T2 weighted tumor volumes and SULmean values were moderately positively correlated (ρ = 0.48, p = 0.01). ADC and D exhibited a moderate negative correlation with SULmean (ρ ≤ -0.42, p < 0.03 for both). K1 and Ktrans were positively correlated (ρ = 0.48, p = 0.01). In contrast, Ktrans and k3max were negatively correlated (ρ = -0.41, p = 0.03). CDA revealed four communities for 16 metrics interconnected with 33 edges in the network. DV, Ktrans, and K1 had 8, 7, and 6 edges in the network, respectively. After validation in a larger population, the CDA approach may aid in identifying useful biomarkers for developing individual patient care in HNSCC.

Harnessing Lactate Metabolism for Radiosensitization

Cancer cells rewire their metabolism to promote cell proliferation, invasion, and metastasis. Alterations in the lactate pathway have been characterized in diverse cancers, correlate with outcomes, and lead to many downstream effects, including decreasing oxidative stress, promoting an immunosuppressive tumor microenvironment, lipid synthesis, and building chemo- or radio-resistance. Radiotherapy is a key modality of treatment for many cancers and approximately 50% of patients with cancer will receive radiation for cure or palliation; thus, overcoming radio-resistance is important for improving outcomes. Growing research suggests that important molecular controls of the lactate pathway may serve as novel therapeutic targets and in particular, radiosensitizers. In this mini-review, we will provide an overview of lactate metabolism in cancer, discuss three important contributors to lactate metabolism (lactate dehydrogenase, monocarboxylate transporters, and mitochondrial pyruvate carrier), and present data that inhibition of these three pathways can lead to radiosensitization. Future research is needed to further understand critical regulators of lactate metabolism and explore clinical safety and efficacy of inhibitors of lactate dehydrogenase, monocarboxylate transporters, and mitochondrial pyruvate carrier alone and in combination with radiation.

Value of PET imaging for radiation therapy

This comprehensive review written by experts in their field gives an overview on the current status of incorporating positron emission tomography (PET) into radiation treatment planning. Moreover, it highlights ongoing studies for treatment individualisation and per-treatment tumour response monitoring for various primary tumours. Novel tracers and image analysis methods are discussed. The authors believe this contribution to be of crucial value for experts in the field as well as for policy makers deciding on the reimbursement of this powerful imaging modality.