Chest wall pain after single-fraction thoracic stereotactic ablative Radiotherapy: Dosimetric analysis from the iSABR trial.

BACKGROUND AND PURPOSE: Concerns over chest wall toxicity has led to debates on treating tumors adjacent to the chest wall with single-fraction stereotactic ablative radiotherapy (SABR). We performed a secondary analysis of patients treated on the prospective iSABR trial to determine the incidence and grade of chest wall pain and modeled dose-response to guide radiation planning and estimate risk. MATERIALS AND METHODS: This analysis included 99 tumors in 92 patients that were treated with 25 Gy in one fraction on the iSABR trial which individualized dose by tumor size and location. Toxicity events were prospectively collected and graded based on the CTCAE version 4. Dose-response modeling was performed using a logistic model with maximum likelihood method utilized for parameter fitting. RESULTS: There were 22 grade 1 or higher chest wall pain events, including five grade 2 events and zero grade 3 or higher events. The volume receiving at least 11 Gy (V11Gy) and the minimum dose to the hottest 2 cc (D2cc) were most highly correlated with toxicity. When dichotomized by an estimated incidence of ≥ 20 % toxicity, the D2cc > 17 Gy (36.6 % vs. 3.7 %, p < 0.01) and V11Gy > 28 cc (40.0 % vs. 8.1 %, p < 0.01) constraints were predictive of chest wall pain, including among a subset of patients with tumors abutting or adjacent to the chest wall. CONCLUSION: For small, peripheral tumors, single-fraction SABR is associated with modest rates of low-grade chest wall pain. Proximity to the chest wall may not contraindicate single fractionation when using highly conformal, image-guided techniques with sharp dose gradients.

Lung Cancer Survival Trends in the Veterans Health Administration.

INTRODUCTION: Lung cancer survival is improving in the United States. We investigated whether there was a similar trend within the Veterans Health Administration (VHA), the largest integrated healthcare system in the United States. MATERIALS AND METHODS: Data from the Veterans Affairs Central Cancer Registry were analyzed for temporal survival trends using Kaplan-Meier estimates and linear regression. RESULTS: A total number of 54,922 Veterans were identified with lung cancer diagnosed from 2010 to 2017. Histologies were classified as non-small-cell lung cancer (NSCLC) (64.2%), small cell lung cancer (SCLC) (12.9%), and 'other' (22.9%). The proportion with stage I increased from 18.1% to 30.4%, while stage IV decreased from 38.9% to 34.6% (both P < .001). The 3-year overall survival (OS) improved for stage I (58.6% to 68.4%, P < .001), stage II (35.5% to 48.4%, P < .001), stage III (18.7% to 29.4%, P < .001), and stage IV (3.4% to 7.8%, P < .001). For NSCLC, the median OS increased from 12 to 21 months (P < .001), and the 3-year OS increased from 24.1% to 38.3% (P < .001). For SCLC, the median OS remained unchanged (8 to 9 months, P = .10), while the 3-year OS increased from 9.1% to 12.3% (P = .014). Compared to White Veterans, Black Veterans with NSCLC had similar OS (P = .81), and those with SCLC had higher OS (P = .003). CONCLUSION: Lung cancer survival is improving within the VHA. Compared to White Veterans, Black Veterans had similar or higher survival rates. The observed racial equity in outcomes within a geographically and socioeconomically diverse population warrants further investigation to better understand and replicate this achievement in other healthcare systems.

Personalized Accelerated ChEmoRadiation (PACER) for Lung Cancer: Protocol for a Bayesian Optimal Phase I/II Trial.

INTRODUCTION: Prior attempts to escalate radiation dose for non-small cell lung cancer (NSCLC) have not improved survival. Given the high risk for cardiopulmonary toxicity with treatment and heterogenous presentation of locally advanced NSCLC, it is unlikely that a single dose regimen is optimal for all patients. This phase I/II trial aims to evaluate a novel treatment approach where the level of accelerated hypofractionation is determined by the predicted toxicity from dose to organs at risk (OARs). METHODS: Patients ≥ 18 years old with lung cancer planned for fractionated radiotherapy to the lung with concurrent chemotherapy will be eligible. Radiation therapy (RT) will be delivered to a total dose of 60 to 66 Gy in 30, 25, or 20 fractions depending on the ability to meet constraints to key organs at risk including the lungs, heart, and esophagus. The primary endpoint is high grade pulmonary, esophageal, or cardiac toxicity. A Bayesian optimized design is used to determine stopping boundaries and evaluate the primary endpoint. CONCLUSION: PACER will evaluate the safety and feasibility of personalized accelerated chemoradiotherapy for lung cancer.

Patient Selection and Outcomes for Hypofractionated Accelerated Radiation and Concurrent Chemotherapy for Non-Small-Cell Lung Cancer.

PURPOSE/OBJECTIVES: Adoption of hypofractionated accelerated radiation therapy (HART) with concurrent chemotherapy has been limited by toxicity concerns. We aimed to describe outcomes of patients treated with HART and concurrent chemotherapy and to evaluate dosimetry to organs at risk to guide patient selection. MATERIALS/METHODS: We evaluated a retrospective cohort of NSCLC patients treated with concurrent chemotherapy with HART (>2.2 Gy per fraction) or standard fractionated radiation therapy (SFRT; 2-2.2 Gy fractions). Dosimetric parameters to key organs at risk were compared, and toxicity, patterns of recurrence and survival were calculated for the cohorts. RESULTS: Fifty-three patients treated with HART were compared with 100 patients treated with SFRT. Median dose per fraction for the HART cohort was 2.75 Gy (range 2.4-3 Gy). HART patients had significantly lower doses to the lung, heart, and esophagus due to patient selection. The HART group and had rates of grade 2+ pneumonitis (9.4 vs. 19%, P = .16) and grade 2+ esophagitis (20.8 vs. 45%, P < .01) that compared favorably to SFRT. Cumulative incidence of in-field recurrence trended lower in the HART cohort (7.6% vs. 23.1%, P = .058). Among the HART group, 88.7% (47/53) met the newly proposed lung constraints based on the degree of hypofractionation CONCLUSION: In select patients with favorable dosimetry to organs at risk, definitive HART with concurrent chemotherapy achieved excellent local control with low toxicity. These results are being used to inform a prospective study on the safety and efficacy of HART with concurrent chemotherapy for select NSCLC patients.

BIOGUIDE-X: A First-in-Human Study of the Performance of Positron Emission Tomography-Guided Radiation Therapy.

PURPOSE: Positron emission tomography (PET)-guided radiation therapy is a novel tracked dose delivery modality that uses real-time PET to guide radiation therapy beamlets. The BIOGUIDE-X study was performed with sequential cohorts of participants to (1) identify the fluorodeoxyglucose (FDG) dose for PET-guided therapy and (2) confirm that the emulated dose distribution was consistent with a physician-approved radiation therapy plan. METHODS AND MATERIALS: This prospective study included participants with at least 1 FDG-avid targetable primary or metastatic tumor (2-5 cm) in the lung or bone. For cohort I, a modified 3 + 3 design was used to determine the FDG dose that would result in adequate signal for PET-guided therapy. For cohort II, PET imaging data were collected on the X1 system before the first and last fractions among patients undergoing conventional stereotactic body radiation therapy. PET-guided therapy dose distributions were modeled on the patient's computed tomography anatomy using the collected PET data at each fraction as input to an "emulated delivery" and compared with the physician-approved plan. RESULTS: Cohort I demonstrated adequate FDG activity in 6 of 6 evaluable participants (100.0%) with the first injected dose level of 15 mCi FDG. In cohort II, 4 patients with lung tumors and 5 with bone tumors were enrolled, and evaluable emulated delivery data points were collected for 17 treatment fractions. Sixteen of the 17 emulated deliveries resulted in dose distributions that were accurate with respect to the approved PET-guided therapy plan. The 17th data point was just below the 95% threshold for accuracy (dose-volume histogram score = 94.6%). All emulated fluences were physically deliverable. No toxicities were attributed to multiple FDG administrations. CONCLUSIONS: PET-guided therapy is a novel radiation therapy modality in which a radiolabeled tumor can act as its own fiducial for radiation therapy targeting. Emulated therapy dose distributions calculated from continuously acquired real-time PET data were accurate and machine-deliverable in tumors that were 2 to 5 cm in size with adequate FDG signal characteristics.

Patterns of Recurrence After Poor Response to Neoadjuvant Chemotherapy in Gastric Cancer and the Role for Adjuvant Radiation.

BACKGROUND: Improved treatment strategies are needed for patients with locally advanced gastric cancer with poor response to neoadjuvant chemotherapy. We aimed to describe patterns of failure for patients with no or partial response (NR, PR) to preoperative chemotherapy. PATIENTS AND METHODS: We analyzed patients with locally advanced gastric cancer treated from 2008 to 2022 with preoperative chemotherapy followed by surgery with D2 resection. We excluded patients who received radiation. Cumulative incidence of locoregional failure (LRF) and distant metastases (DM) were calculated. For patients with recurrent abdominal disease, hypothetical radiation clinical treatment volumes (CTV) were contoured on postoperative scans and compared with patterns of recurrence. RESULTS: A total of 60 patients were identified. The most used preoperative chemotherapy was FLOT (38.6%), followed by FOLFOX (30%) and ECF/ECX/EOX (23.3%). Four (6.7%), 40 (66.7%), and 9 patients (15%) had a complete pathologic response (CR), PR, and NR to neoadjuvant therapy, respectively. Among patients without a CR, 3-year overall and progression-free survival rates were 62.3% (95% CI 48-76.6%) and 51.3% (95% CI 36.9-65.7%), respectively. Three-year cumulative incidence of LRF and DM were 8.4% (95% CI 0.4-16.4%) and 41.0% (95% CI 26.3-55.4%), respectively. Absolute rates of patients having the first site of recurrence encompassed by a postoperative radiation CTV was 2.0% for patients without a CR and 0% for patients with NR. CONCLUSIONS: Patients with locally advanced gastric cancer with less than a CR to chemotherapy have poor outcomes due to high rates of DM. Adjuvant locoregional therapy such as radiation is unlikely to affect survival.

Individualized Stereotactic Ablative Radiotherapy for Lung Tumors: The iSABR Phase 2 Nonrandomized Controlled Trial.

Importance: Stereotactic ablative radiotherapy (SABR) is used for treating lung tumors but can cause toxic effects, including life-threatening damage to central structures. Retrospective data suggested that small tumors up to 10 cm3 in volume can be well controlled with a biologically effective dose less than 100 Gy. Objective: To assess whether individualizing lung SABR dose and fractionation by tumor size, location, and histological characteristics may be associated with local tumor control. Design, Setting, and Participants: This nonrandomized controlled trial (the iSABR trial, so named for individualized SABR) was a phase 2 multicenter trial enrolling participants from November 15, 2011, to December 5, 2018, at academic medical centers in the US and Japan. Data were analyzed from December 9, 2020, to May 10, 2023. Patients were enrolled in 3 groups according to cancer type: initial diagnosis of non-small cell lung cancer (NSCLC) with an American Joint Committee on Cancer 7th edition T1-3N0M0 tumor (group 1), a T1-3N0M0 new primary NSCLC with a history of prior NSCLC or multiple NSCLCs (group 2), or lung metastases from NSCLC or another solid tumor (group 3). Intervention: Up to 4 tumors were treated with once-daily SABR. The dose ranged from 25 Gy in 1 fraction for peripheral tumors with a volume of 0 to 10 cm3 to 60 Gy in 8 fractions for central tumors with a volume greater than 30 cm3. Main outcome: Per-group freedom from local recurrence (same-lobe recurrence) at 1 year, with censoring at time of distant recurrence, death, or loss to follow-up. Results: In total, 217 unique patients (median [IQR] age, 72 [64-80] years; 129 [59%] male; 150 [69%] current or former smokers) were enrolled (some multiple times). There were 240 treatment courses: 79 in group 1, 82 in group 2, and 79 in group 3. A total of 285 tumors (211 [74%] peripheral and 74 [26%] central) were treated. The most common dose was 25 Gy in 1 fraction (158 tumors). The median (range) follow-up period was 33 (2-109) months, and the median overall survival was 59 (95% CI, 49-82) months. Freedom from local recurrence at 1 year was 97% (90% CI, 91%-99%) for group 1, 94% (90% CI, 87%-97%) for group 2, and 96% (90% CI, 89%-98%) for group 3. Freedom from local recurrence at 5 years ranged from 83% to 93% in the 3 groups. The proportion of patients with grade 3 to 5 toxic effects was low, at 5% (including a single patient [1%] with grade 5 toxic effects). Conclusions and Relevance: The results of this nonrandomized controlled trial suggest that individualized SABR (iSABR) used to treat lung tumors may allow minimization of treatment dose and is associated with excellent local control. Individualized dosing should be considered for use in future trials. Trial Registration: ClinicalTrials.gov Identifier: NCT01463423.

Pulmonary Hemorrhage in Patients Treated With Thoracic Stereotactic Ablative Radiotherapy and Antiangiogenic Agents.

INTRODUCTION: Severe pulmonary hemorrhage can occur in patients treated with thoracic stereotactic ablative radiotherapy (SABR) and vascular endothelial growth factor inhibitors (VEGFis). There is limited understanding of which patients are at risk for toxicity with the combination of thoracic SABR and VEGFis or how the risk differs over either therapy alone. METHODS: We evaluated a prospectively maintained cohort of 690 patients with 818 pulmonary tumors treated with highly conformal SABR. Rates of any-grade and grade 3 plus (G3+) pulmonary hemorrhage were compared between patients treated with or without VEGFi therapy across tumor locations. Outcomes were compared between patients treated with SABR plus VEGFi and a propensity-matched cohort of those treated with VEGFi therapy alone. RESULTS: Treatment with VEGFi plus SABR was associated with higher rates of G3+ pulmonary hemorrhage compared with those treated with SABR alone for the overall cohort (3-y incidence: 7.9% versus 0.6%, p < 0.01) and those with central tumors (19.1% versus 3.3%, p = 0.04). When further subdivided, there were significantly higher toxicity rates with VEGFi for the ultracentral (9.0% versus 45.0%, p = 0.044), but not central nonabutting tumors (0.0% versus 1.3%, p = 0.69). There was an increased incidence of G3+ hemorrhage in patients treated with VEGFi plus SABR compared with VEGFi alone (9.6% versus 1.3%, p = 0.04). CONCLUSIONS: The combination of VEGFi and SABR was associated with an increased risk of high-grade pulmonary hemorrhage over either therapy alone. Low rates of toxicity were observed when excluding patients with SABR to ultracentral tumors and applying highly conformal SABR techniques.

Quantitative prediction of aspiration risk in head and neck cancer patients treated with radiation therapy.

OBJECTIVE: To determine characteristics most strongly associated with risk for aspiration events among head and neck cancer (HNC) patients undergoing curative intent treatment. MATERIALS AND METHODS: This was a retrospective, cross-sectional study of 106 patients with previously untreated HNC who received definitive or postoperative radiation therapy (RT) +/- systemic therapy with curative intent. Patients who received post-treatment videofluoroscopic swallow study (VFSS) between 2018-2021 were included. Using ordinal multivariable logistic regression, we modeled the effects of age (>60 years vs. ≤60 years), sex, body mass index (BMI) (>20 kg/m2 vs. ≤20 kg/m2), American Joint Committee on Cancer 8th edition stage (I-II vs. III-IVB), treatment with cisplatin (vs. other or no systemic therapy), post-operative status, primary site (oral cavity vs. P16+ oropharynx vs. P16- Mucosal Site vs. other), and quantitative VFSS measures on Penetration-Aspiration Scale (PAS) score. RESULTS AND CONCLUSION: On ordinal multivariable logistic regression, age >60 years (odds ratio (OR): 3.91, 95% confidence interval (CI): 1.29, 11.9), advanced stage (stage III-IVB) (OR: 3.13, 95% CI: 1.23, 7.79), pharyngeal constriction ratio (PCR) >0.25 (OR: 3.65, 95% CI: 1.14, 11.7), and bolus clearance ratio (BCR) > 0.10 (OR: 3.42, 95% CI: 1.20, 9.75) were found to be significant risk factors for higher PAS scores. Patients with ≥ 2 pre-treatment risk factors had statistically significant increased risk for post-treatment aspiration (OR 2.52, 95% CI: 1.31, 4.86) on ordinal logistic regression. This model could be useful to direct high-risk patients toward interventions designed to reduce risk of aspiration events.

Impact of Delaying Surgery After Chemoradiation on Outcomes for Locally Advanced Esophageal Squamous Cell Carcinoma.

BACKGROUND: Performing selective esophagectomy for locally advanced squamous cell carcinoma may spare patients morbidity, but delayed surgery may infer higher risks. This study evaluated the impact of length of time between chemoradiation and esophagectomy on perioperative outcomes and long-term survival. METHODS: The impact of surgical timing, stratified by surgery performed < 180 and ≥ 180 days from starting radiation, on perioperative outcomes and survival in patients treated with chemoradiation and esophagectomy for cT1N + M0 and cT2-4, any N, M0 squamous cell carcinoma of the mid-distal esophagus in the National Cancer Database (2006-2016) was evaluated with logistic regression, Kaplan-Meier curves, Cox proportional-hazards methods, and propensity-matched analysis. RESULTS: Median time between starting radiation and esophagectomy in 1641 patients was 93 (IQR 81-114) days. Most patients (96.8%, n = 1589) had surgery within 180 days of starting radiation, while 52 patients (3.2%) had delayed surgery. Black race and clinical T stage were associated with delayed surgery. Rates of pathologic upstaging, downstaging, complete response, and positive margins were not significantly different between the groups. Patients with delayed surgery had increased major morbidity as measured by a composite of length of hospital stay, readmission, and 30-day mortality [42.3% (22/52) vs 22.3% (355/1589), p = 0.001]. However, delayed surgery was not associated with a significant difference in survival in both univariate [5-year survival 32.8% (95% CI 21.1-50.7) vs 47.3% (44.7-50.1), p = 0.19] and multivariable analysis [hazard ratio (HR) 1.23 (0.85-1.78), p = 0.26]. CONCLUSIONS: Delaying surgery longer than 180 days after starting chemoradiation for esophageal squamous cell carcinoma is associated with worse perioperative outcomes but not long-term survival.

Isolated Nodal Recurrence After Definitive Stereotactic Ablative Radiation Therapy for Non-Small Cell Lung Cancer.

PURPOSE: Stereotactic ablative radiation therapy (SABR) results in high rates of primary tumor control for early-stage non-small cell lung cancer (NSCLC). For patients with isolated hilar or mediastinal nodal recurrence (INR) after SABR, the optimal salvage treatment strategy is unclear. The purpose of this study was to determine the rate of INR after SABR for early-stage NSCLC and to describe patterns of care and treatment outcomes after salvage therapy. METHODS AND MATERIALS: This retrospective cohort study included 342 patients with stage T1-3N0M0 NSCLC treated with definitive SABR from 2003 to 2018. We evaluated the incidence of INR and baseline factors between patients who did and did not experience INR. Among patients who experienced INR, we described treatment patterns and outcomes including overall survival (OS) and progression free survival (PFS) from the time of nodal failure using the Kaplan-Meier method. RESULTS: With a median follow-up of 3.3 years, the 3-year INR rate was 10.6% (95% CI, 6.6%-13.4%). Among the 34 patients experiencing INR, the 3-year rates of OS and PFS were 39.3% (24.4%-63.3%) and 26.7% (14.1%-0.3%), respectively. The 34 patients with INR were treated with radiation therapy alone (26.7%), concurrent chemoradiation therapy (43.3%), chemotherapy alone (13.3%), or observation (16.7%). Patients treated with concurrent chemoradiation therapy had the best survival outcomes, with a 3-year OS and PFS of 81.5% (61.1%-100.0%) and 63.9% (40.7%-100.0%), respectively. Of the patients treated with salvage radiation therapy or concurrent chemoradiation therapy, 14.3% experienced grade 3 toxic effects, and no patients had grade ≥4 toxic effects. CONCLUSIONS: In this study, INR occurred in approximately 10% of patients treated with SABR for early-stage NSCLC. The highest rates of OS and PFS among patients with INR were observed in those treated with salvage chemoradiation therapy.

Neoadjuvant Therapy in the Post-German Rectal Trial Era: Making Sense in the Absence of Consensus.

Trimodality therapy per the German Rectal Trial has led to excellent locoregional outcomes for locally advanced rectal cancer. Recent efforts have shifted toward improving distant control and health-related quality of life in this disease. To this end, total neoadjuvant therapy has become an increasingly used approach in which most, if not all, chemotherapy is delivered before surgery to improve compliance and to address micrometastases early. To avoid surgical morbidity, a "watch-and-wait" approach, in which total mesorectal excision is deferred, has also been studied for patients who achieve a clinical complete response after chemoradiation. These 2 concurrent treatment trends have raised many points of uncertainty in what used to be a relatively straightforward neoadjuvant treatment paradigm. We discuss here our approach to neoadjuvant therapy for locally advanced rectal cancer, based on the data we currently have and through shared decision-making with patients to help them select the treatment that best aligns with their preferences and values.

Risk of developing subsequent primary lung cancer after receiving radiation for breast cancer.

Background: Radiotherapy (RT) is integral to breast cancer treatment, especially in the current era that emphasizes breast conservation. The aim of our study was to determine the incidence of subsequent primary lung cancer after RT exposure for breast cancer over a time span of 3 decades to quantify this risk over time as modern oncologic treatment continues to evolve. Methods: The SEER (Surveillance, Epidemiology, and End Results) database was queried from 1988 to 2014 for patients diagnosed with nonmetastatic breast cancer. Patients who subsequently developed primary lung cancer were identified. Multivariable regression modeling was performed to identify independent factors associated with the development of lung cancer stratified by follow up intervals of 5 to 9 years, 10 to 15 years, and >15 years after breast cancer diagnosis. Results: Of the 612,746 patients who met our inclusion criteria, 319,014 (52%) were irradiated. primary lung cancer developed in 5556 patients (1.74%) in the RT group versus 4935 patients (1.68%) in the non-RT group. In a multivariable model stratified by follow-up duration, the overall HR of developing subsequent ipsilateral lung cancer in the RT group was 1.14 (P = .036) after 5 to 9 years of follow-up, 1.28 (P = .002) after 10 to 15 years of follow-up, and 1.30 (P = .014) after >15 years of follow-up. The HR of contralateral lung cancer was not increased at any time interval. Conclusions: The increased risk of developing a primary lung cancer secondary to RT exposure for breast cancer is much lower than previously published. Modern RT techniques may have contributed to the improved risk profile, and this updated study is important for counseling and surveillance of breast cancer patients.

Evaluating High-Dimensional Machine Learning Models to Predict Hospital Mortality Among Older Patients With Cancer.

PURPOSE: Older hospitalized cancer patients face high risks of hospital mortality. Improved risk stratification could help identify high-risk patients who may benefit from future interventions, although we lack validated tools to predict in-hospital mortality for patients with cancer. We evaluated the ability of a high-dimensional machine learning prediction model to predict inpatient mortality and compared the performance of this model to existing prediction indices. METHODS: We identified patients with cancer older than 75 years from the National Emergency Department Sample between 2016 and 2018. We constructed a high-dimensional predictive model called Cancer Frailty Assessment Tool (cFAST), which used an extreme gradient boosting algorithm to predict in-hospital mortality. cFAST model inputs included patient demographic, hospital variables, and diagnosis codes. Model performance was assessed with an area under the curve (AUC) from receiver operating characteristic curves, with an AUC of 1.0 indicating perfect prediction. We compared model performance to existing indices including the Modified 5-Item Frailty Index, Charlson comorbidity index, and Hospital Frailty Risk Score. RESULTS: We identified 2,723,330 weighted emergency department visits among older patients with cancer, of whom 144,653 (5.3%) died in the hospital. Our cFAST model included 240 features and demonstrated an AUC of 0.92. Comparator models including the Modified 5-Item Frailty Index, Charlson comorbidity index, and Hospital Frailty Risk Score achieved AUCs of 0.58, 0.62, and 0.71, respectively. Predictive features of the cFAST model included acute conditions (respiratory failure and shock), chronic conditions (lipidemia and hypertension), patient demographics (age and sex), and cancer and treatment characteristics (metastasis and palliative care). CONCLUSION: High-dimensional machine learning models enabled accurate prediction of in-hospital mortality among older patients with cancer, outperforming existing prediction indices. These models show promise in identifying patients at risk of severe adverse outcomes, although additional validation and research studying clinical implementation of these tools is needed.

Validation of NRG Oncology's prognostic nomograms for oropharyngeal cancer in the Veterans Affairs database.

BACKGROUND: To test whether nomograms developed by NRG Oncology for oropharyngeal squamous cell carcinoma (OPSCC) patients could be validated in an independent population-based sample. METHODS: The authors tested nomograms for estimating progression-free survival (PFS) and overall survival (OS) in patients from the Veterans Health Administration with previously untreated locoregionally advanced OPSCC, diagnosed between 2008 and 2017, managed with definitive radiotherapy with or without adjuvant systemic therapy. Covariates were age, performance status, p16 status, T/N category, smoking history, education history, weight loss, marital status, and anemia. We used multiple imputation to handle missing data and performed sensitivity analyses on complete cases. Validation was assessed via Cox proportional hazards models, log-rank tests, and c-indexes. RESULTS: A total of 4007 patients met inclusion criteria (658 patients had complete data). Median follow-up time was 3.20 years, with 967 progression events and 471 noncancer deaths. Each risk score was associated with poorer outcomes per unit increase (PFS score, hazard ratio [HR], 1.42 [1.37-1.47]; OS score, HR, 1.40 [1.34-1.45]). By risk score quartile, 2-year PFS estimates were 89.2%, 78.5%, 65.8%, and 48.3%; OS estimates were 92.6%, 83.6%, 73.9%, and 51.3%, respectively (P < .01 for all comparisons). C-indices for models of PFS and OS were 0.65 and 0.67, for all patients, respectively (0.69 and 0.73 for complete cases). The nomograms slightly overestimated PFS and OS in the overall cohort but exhibited high agreement in complete cases. CONCLUSIONS: NRG nomograms were effective for predicting PFS and OS for patients with OPSCC, supporting their broader applicability in the OPSCC population undergoing definitive radiotherapy.

Bias Reduction through Analysis of Competing Events (BRACE) Correction to Address Cancer Treatment Selection Bias in Observational Data.

PURPOSE: Cancer treatments can paradoxically appear to reduce the risk of noncancer mortality in observational studies, due to residual confounding. Here we introduce a method, Bias Reduction through Analysis of Competing Events (BRACE), to reduce bias in the presence of residual confounding. EXPERIMENTAL DESIGN: BRACE is a novel method for adjusting for bias from residual confounding in proportional hazards models. Using standard simulation methods, we compared BRACE with Cox proportional hazards regression in the presence of an unmeasured confounder. We examined estimator distributions, bias, mean squared error (MSE), and coverage probability. We then estimated treatment effects of high versus low intensity treatments in 36,630 prostate cancer, 4,069 lung cancer, and 7,117 head/neck cancer patients, using the Veterans Affairs database. We analyzed treatment effects on cancer-specific mortality (CSM), noncancer mortality (NCM), and overall survival (OS), using conventional multivariable Cox and propensity score (adjusted using inverse probability weighting) models, versus BRACE-adjusted estimates. RESULTS: In simulations with residual confounding, BRACE uniformly reduced both bias and MSE. In the absence of bias, BRACE introduced bias toward the null, albeit with lower MSE. BRACE markedly improved coverage probability, but with a tendency toward overcorrection for effective but nontoxic treatments. For each clinical cohort, more intensive treatments were associated with significantly reduced hazards for CSM, NCM, and OS. BRACE attenuated OS estimates, yielding results more consistent with findings from randomized trials and meta-analyses. CONCLUSIONS: BRACE reduces bias and MSE when residual confounding is present and represents a novel approach to improve treatment effect estimation in nonrandomized studies.

Temporal Trends and Predictors of Opioid Use Among Older Patients With Cancer.

OBJECTIVES: While opioids represent a cornerstone of cancer pain management, the timing and patterns of opioid use in the cancer population have not been well studied. This study sought to explore longitudinal trends in opioid use among Medicare beneficiaries with nonmetastatic cancer. MATERIALS AND METHODS: Within a cohort of 16,072 Medicare beneficiaries ≥66 years old diagnosed with nonmetastatic cancer between 2007 and 2013, we determined the likelihood of receiving a short-term (0 to 6 mo postdiagnosis), intermediate-term (6 to 12 mo postdiagnosis), long-term (1 to 2 y postdiagnosis), and high-risk (morphine equivalent dose ≥90 mg/day) opioid prescription after cancer diagnosis. Multivariable logistic regression models were used to identify patient and cancer risk factors associated with these opioid use endpoints. RESULTS: During the study period, 74.6% of patients received an opioid prescription, while only 2.66% of patients received a high-risk prescription. Factors associated with use varied somewhat between short-term, intermediate-term, and long-term use, though in general, patients at higher risk of receiving an opioid prescription after their cancer diagnosis were younger, had higher stage disease, lived in regions of higher poverty, and had a history of prior opioid use. Prescriptions for high-risk opioids were associated with individuals living in regions with lower poverty. CONCLUSIONS: Temporal trends in opioid use in cancer patients depend on patient, demographic, and tumor characteristics. Overall, understanding these correlations may help physicians better identify patient-specific risks of opioid use and could help better inform future evidence-based, cancer-specific opioid prescription guidelines.