Site-specific patterns of early-stage cancer diagnosis during the COVID-19 pandemic

The COVID-19 pandemic caused widespread disruptions in cancer care. We hypothesized that the greatest disruptions in diagnosis occurred in screen-detected cancers. We identified patients (≥18 years of age) with newly diagnosed cancer from 2019 to 2020 in the US National Cancer Database and calculated the change in proportion of early-stage to late-stage cancers using a weighted linear regression. Disruptions in early-stage diagnosis were greater than in late-stage diagnosis (17% vs 12.5%). Melanoma demonstrated the greatest relative decrease in early-stage vs late-stage diagnosis (22.9% vs 9.2%), whereas the decrease was similar for pancreatic cancer. Compared with breast cancer, cervical, melanoma, prostate, colorectal, and lung cancers showed the greatest disruptions in early-stage diagnosis. Uninsured patients experienced greater disruptions than privately insured patients. Disruptions in cancer diagnosis in 2020 had a larger impact on early-stage disease, particularly screen-detected cancers. Our study supports emerging evidence that primary care visits may play a critical role in early melanoma detection.

Updated Analysis of Comparative Toxicity of Proton and Photon Radiation for Prostate Cancer

PURPOSE

Previous comparative effectiveness studies have not demonstrated a benefit of proton beam therapy (PBT) compared with intensity-modulated radiation therapy (IMRT) for prostate cancer. An updated comparison of GI and genitourinary (GU) toxicity is needed.

METHODS

We investigated the SEER-Medicare linked database, identifying patients with localized prostate cancer diagnosed from 2010 to 2017. Procedure and diagnosis codes indicative of treatment-related toxicity were identified. As a sensitivity analysis, we also identified toxicity based only on procedure codes. Patients who underwent IMRT and PBT were matched 2:1 on the basis of clinical and sociodemographic characteristics. We then compared GI and GU toxicity at 6, 12, and 24 months after treatment.

RESULTS

The final sample included 772 PBT patients matched to 1,544 IMRT patients. The frequency of GI toxicity for IMRT versus PBT was 3.5% versus 2.5% at 6 months (P = .18), 9.5% versus 10.2% at 12 months (P = .18), and 20.5% versus 23.4% at 24 months (P = .11). The frequency of only procedure codes indicative of GI toxicity for IMRT versus PBT was too low to be reported and not significantly different. The frequency of GU toxicity for IMRT versus PBT was 6.8% versus 5.7% (P = .30), 14.3% versus 12.2% (P = .13), and 28.2% versus 25.8% (P = .21) at 6, 12, and 24 months, respectively. When looking only at procedure codes, the frequency of GU toxicity for IMRT was 1.0% at 6 months, whereas it was too infrequent to report for PBT (P = .64). GU toxicity for IMRT versus PBT was 3.3% versus 2.1% (P = .10), and 8.7% versus 6.7% (P = .10) at 12 and 24 months, respectively.

CONCLUSION

In this observational study, there were no statistically significant differences between PBT and IMRT in terms of GI or GU toxicity.

Enhancing Safety in AI-Driven Cone Beam CT-based Online Adaptive Radiation Therapy: Development and Implementation of an Interdisciplinary Workflow

Purpose

The emerging online adaptive radiation therapy (OART) treatment strategy based on cone beam computed tomography allows for real-time replanning according to a patient's current anatomy. However, implementing this procedure requires a new approach across the patient's care path and monitoring of the "black box" adaptation process. This study identifies high-risk failure modes (FMs) associated with AI-driven OART and proposes an interdisciplinary workflow to mitigate potential medical errors from highly automated processes, enhance treatment efficiency, and reduce the burden on clinicians.

Methods and Materials

An interdisciplinary working group was formed to identify safety concerns in each process step using failure mode and effects analysis (FMEA). Based on the FMEA results, the team designed standardized procedures and safety checklists to prevent errors and ensure successful task completion. The Risk Priority Numbers (RPNs) for the top twenty FMs were calculated before and after implementing the proposed workflow to evaluate its effectiveness. Three hundred seventy-four adaptive sessions across 5 treatment sites were performed, and each session was evaluated for treatment safety and FMEA assessment.

Results

The OART workflow has 4 components, each with 4, 8, 13, and 4 sequentially executed tasks and safety checklists. Site-specific template preparation, which includes disease-specific physician directives and Intelligent Optimization Engine template testing, is one of the new procedures introduced. The interdisciplinary workflow significantly reduced the RPNs of the high-risk FMs, with an average decrease of 110 (maximum reduction of 305.5 and minimum reduction of 27.4).

Conclusions

This study underscores the importance of addressing high-risk FMs associated with AI-driven OART and emphasizes the significance of safety measures in its implementation. By proposing a structured interdisciplinary workflow and integrated checklists, the study provides valuable insights into ensuring the safe and efficient delivery of OART while facilitating its effective integration into clinical practice.

Prognosis and risk of suicide after cancer diagnosis

INTRODUCTION

Suicide rates are elevated after cancer diagnosis. Existential distress caused by awareness of one's impending death is well-described in patients with cancer. The authors hypothesized that suicide risk is associated with cancer prognosis, and the impact of prognosis on suicide risk is greatest for populations with higher baseline suicide risk.

METHODS

The authors identified patients (≥16 years old) with newly diagnosed cancers from 2000 to 2019 in the Surveillance, Epidemiology, and End Results database, representing 27% of US cancers. Multiple primary-standardized mortality ratios (SMR) were used to estimate the relative risk of suicide within 6 months of diagnosis compared to the general US population, adjusted for age, sex, race, and year of follow-up. Suicide rates by 20 most common cancer sites were compared with respective 2-year overall survival rates (i.e., prognosis) using a weighted linear regression model.

RESULTS

Among 6,754,704 persons diagnosed with cancer, there were 1610 suicide deaths within 6 months of diagnosis, three times higher than the general population (SMR = 3.1; 95% confidence interval, 3.0-3.3). Suicide risk by cancer site was closely associated with overall prognosis (9.5%/percent survival deficit, R2  = 0.88, p < .0001). The association of prognosis with suicide risk became attenuated over time. For men, the risk of suicide increased by 2.8 suicide deaths per 100,000 person-years (p < .0001) versus 0.3 in women (p < .0001). The risk was also higher for persons ≥60 old and for the White (vs. Black) race.

CONCLUSIONS

Poorer prognosis was closely associated with suicide risk early after cancer diagnosis and had a greater effect on populations with higher baseline risks of suicide. This model highlights the need for enhanced psychiatric surveillance and continued research in this patient population.

Scorecards: Quantifying Dosimetric Plan Quality in Pancreatic Ductal Adenocarcinoma Stereotactic Body Radiation Therapy

Purpose

A scoring mechanism called the scorecard that objectively quantifies the dosimetric plan quality of pancreas stereotactic body radiation therapy treatment plans is introduced.

Methods and Materials

A retrospective analysis of patients with pancreatic ductal adenocarcinoma receiving stereotactic body radiation therapy at our institution between November 2019 and November 2020 was performed. Ten patients were identified. All patients were treated to 36 Gy in 5 fractions, and organs at risk (OARs) were constrained based on Alliance A021501. The scorecard awarded points for OAR doses lower than those cited in Alliance A021501. A team of 3 treatment planners and 2 radiation oncologists, including a physician resident without plan optimization experience, discussed the relative importance of the goals of the treatment plan and added additional metrics for OARs and plan quality indexes to create a more rigorous scoring mechanism. The scorecard for this study consisted of 42 metrics, each with a unique piecewise linear scoring function which is summed to calculate the total score (maximum possible score of 365). The scorecard-guided plan, the planning and optimization for which were done exclusively by the physician resident with no prior plan optimization experience, was compared with the clinical plan, the planning and optimization for which were done by expert dosimetrists, using the Sign test.

Results

Scorecard-guided plans had, on average, higher total scores than those clinically delivered for each patient, averaging 280.1 for plans clinically delivered and 311.7 for plans made using the scorecard (P = .003). Additionally, for most metrics, the average score of each metric across all 10 patients was higher for scorecard-guided plans than for clinically delivered plans. The scorecard guided the planner toward higher coverage, conformality, and OAR sparing.

Conclusions

A scorecard tool can help clarify the goals of a treatment plan and provide an objective method for comparing the results of different plans. Our study suggests that a completely novice treatment planner can use a scorecard to create treatment plans with enhanced coverage, conformality, and improved OAR sparing, which may have significant effects on both tumor control and toxicity. These tools, including the scorecard used in this study, have been made freely available.

Acute and Chronic Complications After Treatment of Locoregional Anal Cancer: Prevention and Management Strategies

Definitive chemoradiotherapy (CRT) for anal cancer spares patients the morbidity of a colostomy surgery and optimizes cancer outcomes. CRT, however, has introduced a unique acute and chronic toxicity profile, which has greatly improved over the years with the introduction of advanced radiotherapy techniques. This article provides the multidisciplinary care team with practical tools to mitigate and manage acute and chronic complications from definitive treatment of anal cancer.

MGMT Promoter Methylation Predicts Overall Survival after Chemotherapy for 1p/19q-Codeleted Gliomas

PURPOSE

While MGMT promoter methylation (mMGMT) is predictive of response to alkylating chemotherapy and guides treatment decisions in glioblastoma, its role in grade 2 and 3 glioma remains unclear. Recent data suggest that mMGMT is prognostic of progression-free survival in 1p/19q-codeleted oligodendrogliomas, but an effect on overall survival (OS) has not been demonstrated.

EXPERIMENTAL DESIGN

We identified patients with newly diagnosed 1p/19q-codeleted gliomas and known MGMT promoter status in the National Cancer Database from 2010 to 2019. Multivariable Cox proportional hazards regression modeling was used to assess the effect of mMGMT on OS after adjusting for age, sex, race, comorbidity, grade, extent of resection, chemotherapy, and radiotherapy.

RESULTS

We identified 1,297 eligible patients, 938 (72.3%) of whom received chemotherapy in their initial course of treatment. The MGMT promoter was methylated in 1,009 (77.8%) patients. Unmethylated MGMT (uMGMT) was associated with worse survival compared with mMGMT [70% {95% confidence interval (CI), 64%-77%} vs. 81% (95% CI, 78%-85%); P < 0.001; adjusted HR (aHR), 2.35 (95% CI, 1.77-3.14)]. uMGMT was associated with worse survival in patients who received chemotherapy [63% (95% CI, 55-73%) vs. 80% (95% CI, 76%-84%); P < 0.001; aHR, 2.61 (95% CI, 1.89-3.60)] but not in patients who did not receive chemotherapy [P = 0.38; HR, 1.31 (95% CI, 0.71-2.42)]. Similar results were observed regardless of World Health Organization grade and after single- or multiagent chemotherapy.

CONCLUSIONS

Our study demonstrates an association between mMGMT and OS in 1p/19q-codeleted gliomas. MGMT promoter status should be considered as a stratification factor in future clinical trials of 1p/19q-codeleted gliomas that use OS as an endpoint.

Creation and Implementation of an Interdisciplinary Workflow for CBCT-Based Online Adaptive Radiotherapy

PURPOSE/OBJECTIVE(S)

CBCT-based online adaptive radiotherapy (OART) is an emerging treatment strategy to replan based on the anatomy of the day while the patient remains on the couch. OART is not just an add-on to the current workflow; it necessitates a new approach across the patient's path of care, from CT simulation to treatment delivery. OART requires the addition of duties to clinical personnel, strategies to create auto-plan templates, and monitoring the "black box" adaptation process. Studies have shown that OART implementation is limited by its resource-intensive nature and the risks associated with the treatment approach. We hypothesized that the implementation of an interdisciplinary, streamlined workflow and checklists would enhance the OART treatment efficiency, prevent medical errors from the adaptation, and minimize the burden on clinicians.

MATERIALS/METHODS

An interdisciplinary OART working group comprising radiation oncologists, medical physicists, dosimetrists, and therapists was created to enable weekly knowledge sharing, workflow design, implementation, and continuous process improvement. 213 adaptive sessions from 5 treatment sites (pancreas, bladder, prostate, rectum, anus) were treated on a CBCT-based OART platform in a single institutional study. An evaluation of the treatment safety and workflow time was performed for each adaptive session.

RESULTS

The OART workflow was divided into four sub-workflows: 1) pre-treatment site-specific template preparation, 2) pre-treatment initial planning and verification, 3) on-treatment procedure, and 4) post-treatment evaluation. The sub-processes involved 4, 8, 13, and 4 separate, sequentially tasks, respectively, and a total of 11 task checklists. The template preparation is a new process developed for site-specific, standardized physician template directives, automated planning template development, and testing for its accuracy and robustness. The planning templates generated high-quality initial plans automatically within minutes once structures were segmented on the planning CT. This process was replicated during treatment using the CBCT. The median (interquartile range) online procedure time, defined as the time from initial CBCT to plan approval, of the five treatment sites (pancreas, bladder, prostate, rectum, anus) was 22.1 (19.2-24.8) min, 16.5 (15.3-17.5) min, 14.7 (13.9-17.4) min, 17 (15.3-19.7) min, and 24 (21.4-25.8) min, respectively. Safety assessment determined that no treatment deviations were observed.

CONCLUSION

Creating an interdisciplinary, standardized workflow and checklists allowed the safe delivery of OART with clinically feasible online procedure time and significantly reduced initial planning time compared with traditional EBRT. The unique workflow is essential to minimize the burden on the care team, increase patient safety, and access to OART.

CT-Guided Online Adaptive Stereotactic Body Radiotherapy for Pancreas Ductal Adenocarcinoma: Dosimetric and Initial Clinical Experience

PURPOSE/OBJECTIVE(S)

Retrospective analysis suggests that dose escalation to a biologically effective dose of more than 70 Gy may improve overall survival in patients with pancreatic ductal adenocarcinoma (PDAC), but such treatments in practice are limited by proximity of organs at risk (OARs). We hypothesized that CT-guided online adaptive radiotherapy (OART) can account for interfraction movement of OARs, reduce dose to OARs, and improve coverage of targets.

MATERIALS/METHODS

This is a single institution retrospective analysis of patients with PDAC treated with OART on a CBCT-based OART platform. All patients were treated to 40 Gy in 5 fractions. PTV overlapping with a 5 mm planning risk volume expansion on the stomach, duodenum and bowel received 25 Gy. Initial treatment plans were created conventionally. For each fraction, PTV and OAR volumes were recontoured with AI assistance after initial cone beam CT (CBCT). The adapted plan was calculated, underwent QA, and then compared to the scheduled plan. A second CBCT was obtained prior to delivery of the selected plan. Total treatment time (first CBCT to end of radiation delivery) and active physician time (first to second CBCT) were recorded. PTV_4000 V95%, PTV_2500 V95%, and D0.03 cc to stomach, duodenum and bowel were reported for scheduled (S) and adapted (A) plans. CTCAEv5.0 toxicities were recorded. Statistical analysis was performed using a two-sided T test and α of 0.05.

RESULTS

Seven patients with unresectable or locally-recurrent PDAC were analyzed, with a total of 35 fractions. Average total time was 33:00 minutes (22:25-49:40) and average active time was 22:48 minutes (14:15-39:34). All fractions were treated with adapted plans. All adapted plans met PTV_4000 V95.0% > 95.0% coverage goal and OAR dose constraints. Dosimetric data for scheduled and adapted plans per fraction are in Table 1. Median follow up was 1.7 months. 5 (71%) patients experienced either Grade 1 or 2 toxicities. No patients experienced Grade 3+ toxicities.

CONCLUSION

Daily OART significantly reduced dose OARs while achieving superior PTV coverage. Treatment was generally well tolerated with no grade 3+ acute toxicity, and required only 22:48 minutes on average of active physician time. Our initial clinical experience demonstrates OART allows for safe dose escalation in the treatment of PDAC.

Adaptive Radiation Therapy: A Review of CT-based Techniques

Adaptive radiation therapy is a feedback process by which imaging information acquired over the course of treatment, such as changes in patient anatomy, can be used to reoptimize the treatment plan, with the end goal of improving target coverage and reducing treatment toxicity. This review describes different types of adaptive radiation therapy and their clinical implementation with a focus on CT-guided online adaptive radiation therapy. Depending on local anatomic changes and clinical context, different anatomic sites and/or disease stages and presentations benefit from different adaptation strategies. Online adaptive radiation therapy, where images acquired in-room before each fraction are used to adjust the treatment plan while the patient remains on the treatment table, has emerged to address unpredictable anatomic changes between treatment fractions. Online treatment adaptation places unique pressures on the radiation therapy workflow, requiring high-quality daily imaging and rapid recontouring, replanning, plan review, and quality assurance. Generating a new plan with every fraction is resource intensive and time sensitive, emphasizing the need for workflow efficiency and clinical resource allocation. Cone-beam CT is widely used for image-guided radiation therapy, so implementing cone-beam CT-guided online adaptive radiation therapy can be easily integrated into the radiation therapy workflow and potentially allow for rapid imaging and replanning. The major challenge of this approach is the reduced image quality due to poor resolution, scatter, and artifacts. Keywords: Adaptive Radiation Therapy, Cone-Beam CT, Organs at Risk, Oncology © RSNA, 2023.

Risk of Squamous Cell Carcinoma of the Breast Following Postmastectomy Implant Reconstruction in Women With Breast Cancer and Carcinoma in Situ

This cohort study uses national surveillance data to describe the incidence and risk of squamous cell carcinoma after postmastectomy implant reconstruction in women with breast cancer.

Impact of Adapted Radiotherapy Schedules on Bowel Sparing in Node-Positive Cervical Cancer

PURPOSE

Definitive radiation therapy (RT) for locally advanced node-positive cervical cancer confers significant toxicity to pelvic organs including the small bowel. Gross nodal disease exhibits significant shrinkage during RT, and yet conventional RT does not account for this change. We evaluated the reduction in absorbed bowel dose using various adaptive RT schedules.

METHODS AND MATERIALS

We obtained 130 evaluable scans (computed tomography simulation and 25 cone beam computed tomography scans per patient) of 5 patients who had received definitive external beam RT for lymph node positive cervical cancer daily over 5 weeks. Using a single universal volumetric modulated arc therapy plan with predefined optimization priorities, we created adapted RT plans in 4 schedules: Daily, Weekly, Twice, and NoAdapt (mimicking conventional nonadapted RT). The in silico (computer modeled) patients were treated to 45 Gy to primary cervical disease with a simultaneous integrated boost to 55 Gy to involved lymph nodes. We evaluated dose metrics including D2cc, D15cc, and V45 to determine the impact of adapted RT schedules on bowel sparing. Statistical tests included the Student t test, analysis of variance, and the Spearman rank correlation.

RESULTS

The quantity of reduced bowel dose was significantly associated with the chosen planning schedule in all evaluated metrics and was proportional to the frequency of adaptive RT with significant moderate-to-strong monotonicity. Both D2cc and D15cc were reduced an average of 2.7 Gy using daily replanning compared with a nonadapted approach. A minimally adapted strategy of only 2 replans also confers a significant dosimetric benefit over a nonadapted approach. Reduced standard deviations of D2cc and V45 bowel doses over the treatment courses were significantly associated with the choice of planning schedule with strong monotonicity.

CONCLUSIONS

All adaptive RT schedules evaluated confer significant dosimetric advantages in bowel sparing over a conventional nonadapted technique, with greater sparing seen with more frequent replanning schedules. These findings warrant future trials of adaptive RT for pelvic malignancies.

Adjuvant Chemoradiation in Patients with Lymph Node-Positive Biliary Tract Cancers: Secondary Analysis of a Single-Arm Clinical Trial (SWOG 0809)

BACKGROUND

SWOG 0809 is the only prospective study of adjuvant chemotherapy followed by chemoradiation focusing on margin status in patients with extrahepatic cholangiocarcinoma (EHCC) and gallbladder cancer (GBCA); however, the effects of adjuvant therapy by nodal status have never been reported in this population.

METHODS

Patients with resected EHCC and GBCA, stage pT2-4, node-positive (N+) or margin-positive (R1) who completed four cycles of chemotherapy followed by radiotherapy were included. Cox regression was used to compare overall survival (OS), disease-free survival (DFS), local recurrence, and distant metastasis by nodal status. DFS rates were compared with historical data via a one-sample t-test.

RESULTS

Sixty-nine patients [EHCC, n = 46 (66%); GBCA, n = 23 (33%)] were evaluated, with a median age of 61.7 years and an R0 rate of 66.7% and R1 rate of 33.3%. EHCC versus GBCA was more likely to be N+ (73.9% vs. 47.8%, p = 0.03). Nodal status did not significantly impact OS (hazard ratio [HR] 1.98, 95% confidence interval [CI] 0.86-4.54, p = 0.11) or DFS (HR 1.63, 95% CI 0.77-3.44, p = 0.20). Two-year OS was 70.6% for node-negative (N0) disease and 60.9% for N+ disease, while 2-year DFS was 62.5% for N0 tumors and 49.8% for N+ tumors. N+ versus N0 tumors showed higher rates of distant failure (42.2% vs. 25.0%, p = 0.04). The 2-year DFS rate in N+ tumors was significantly higher than in historical controls (49.8% vs. 29.7%, p = 0.004).

CONCLUSIONS

Adjuvant therapy is associated with favorable outcome independent of nodal status and may impact local control in N+ patients. These data could serve as a benchmark for future adjuvant trials, including molecular-targeted agents.

National Patterns of Early Adoption of Magnetic Resonance Imaging-Guided Linear Accelerators in 2018 to 2019

Purpose

Adaptive magnetic resonance imaging-guided linear accelerators (aMRI-LINACs) are an emerging technology with the potential to improve radiation treatment for cancer through improved visualization and adaptive treatment. Given the competing forces of the increased cost, knowledge, and staff required for aMRI-LINAC therapy, it is unpredictable how rapidly and for whom aMRI-LINAC therapy is being adopted. Therefore, given that aMRI-LINAC therapy was granted approval from the Food and Drug Administration in late 2017, we evaluated the National Cancer Database (NCDB) to obtain a nationwide view of early aMRI-LINAC adoption in 2018 to 2019.

Methods and Materials

Forty-three disease sites were aggregated. A sample of patients who underwent intensity modulated radiation therapy (IMRT) from 2018 to 2019 were matched 1:1 by stage for the top 4 cancer sites. We then compared 9 characteristics of interest (age, % White [vs non-White], % residing in metro areas, % living in the greatest income quartile, % insured by Medicare, % uninsured or unknown insurance status, % treated at a comprehensive cancer center or academic center, % with no recorded Charlson-Deyo comorbidities, and % residing in an area with highest educational) between the 2 samples (aMRI-LINAC and matched IMRT).

Results

Only 171 patients were recorded as having been treated with aMRI-LINACs in the NCDB in 2018 to 2019. Fifty-six percent were male, 89% White, and 54% enrolled in Medicare. The most common sites of disease treated were lung (33 patients), pancreas (30 patients), prostate (29 patients), and breast (23 patients). There were no significant differences between aMRI-LINAC- and IMRT-matched patients except that patients with lung or breast cancer treated with aMRI-LINAC were significantly more likely to be treated at a comprehensive cancer center or academic center.

Conclusions

aMRI-LINAC adoption recorded in the NCDB after Food and Drug Administration approval was potentially underreported, slow, and attributed to academic sites of practice. Further longitudinal study will be needed to assess how practice patterns evolve with greater adoption.

Risk of Anaplastic Large Cell Lymphoma Following Postmastectomy Implant Reconstruction in Women With Breast Cancer and Ductal Carcinoma in Situ

This cohort study examines the risk of anaplastic large cell lymphoma (ALCL) following postmastectomy implant reconstruction among US women with breast cancer and ductal carcinoma in situ (DCIS).

Long-term follow-up experience with adjuvant therapy after irreversible electroporation of locally advanced pancreatic cancer

BACKGROUND

Irreversible electroporation (IRE) expands the surgical options for patients with unresectable pancreatic cancer. This study evaluated for differences in survival stratified by type of IRE and receipt of adjuvant chemotherapy.

METHODS

Patients with locally advanced pancreatic cancer treated by IRE (2012-2020) were retrospectively included. Overall survival (OS) and recurrence-free survival (RFS) were compared by type of IRE (in situ for local tumor control or IRE of potentially positive margins with resection) and by receipt of adjuvant chemotherapy.

RESULTS

Thirty-nine patients had IRE in situ, 61 had IRE for margin extension, and 19 received adjuvant chemotherapy. Most (97.00%) underwent induction chemotherapy. OS was 28.71 months (interquartile range [IQR] 19.17, 51.19) from diagnosis, with no difference by IRE type (hazard ratio [HR] 1.05 for margin extension [p = 0.85]) or adjuvant chemotherapy (HR 1.14 [p = 0.639]). RFS was 8.51 months (IQR 4.95, 20.17) with no difference by IRE type (HR 0.90 for margin extension [p = 0.694]) or adjuvant chemotherapy (HR 0.90 [p = 0.711]).

CONCLUSION

These findings suggest that adjuvant therapy may have limited benefit for patients treated with induction chemotherapy followed by local control with IRE for unresectable pancreatic cancer. Further study of the duration and timing of systemic therapy is warranted to maximize benefit and limit toxicity.

Anal Cancer: Emerging Standards in a Rare Rare Disease

The social stigma surrounding an anal cancer diagnosis has traditionally prevented open discussions about this disease. However, as recent treatment options and an increasing rate of diagnoses are made worldwide, awareness is growing. In the United States alone, 9,090 individuals were expected to be diagnosed with anal cancer in 2021. The US annual incidence of squamous cell carcinoma of the anus continues to increase by 2.7% yearly, whereas the mortality rate increases by 3.1%. The main risk factor for anal cancer is a human papillomavirus infection; those with chronic immunosuppression are also at risk. Patients with HIV are 19 times more likely to develop anal cancer compared with the general population. In this review, we have provided an overview of the carcinoma of the anal canal, the role of screening, advancements in radiation therapy, and current trials investigating acute and chronic treatment-related toxicities. This article is a comprehensive approach to presenting the existing data in an effort to encourage continuous international interest in anal cancer.

Neoadjuvant chemoradiation alters the immune microenvironment in pancreatic ductal adenocarcinoma

Patients with pancreatic ductal adenocarcinoma (PDAC) have a grim prognosis despite complete surgical resection and intense systemic therapies. While immunotherapies have been beneficial with many different types of solid tumors, they have almost uniformly failed in the treatment of PDAC. Understanding how therapies affect the tumor immune microenvironment (TIME) can provide insights for the development of strategies to treat PDAC. We used quantitative multiplexed immunofluorescence (qmIF) quantitative spatial analysis (qSA), and immunogenomic (IG) analysis to analyze formalin-fixed paraffin embedded (FFPE) primary tumor specimens from 44 patients with PDAC including 18 treated with neoadjuvant chemoradiation (CRT) and 26 patients receiving no treatment (NT) and compared them with tissues from 40 treatment-naïve melanoma patients. We find that relative to NT tumors, CD3+ T cell infiltration was increased in CRT treated tumors (p = .0006), including increases in CD3+CD8+ cytotoxic T cells (CTLs, p = .0079), CD3+CD4+FOXP3- T helper cells (Th, p = .0010), and CD3+CD4+FOXP3+ regulatory T cells (Tregs, p = .0089) with no difference in CD68+ macrophages. IG analysis from micro-dissected tissues indicated overexpression of genes involved in antigen presentation, T cell activation, and inflammation in CRT treated tumors. Among treated patients, a higher ratio of Tregs to total T cells was associated with shorter survival time (p = .0121). Despite comparable levels of infiltrating T cells in CRT PDACs to melanoma, PDACs displayed distinct spatial profiles with less T cell clustering as defined by nearest neighbor analysis (p < .001). These findings demonstrate that, while CRT can achieve high T cell densities in PDAC compared to melanoma, phenotype and spatial organization of T cells may limit benefit of T cell infiltration in this immunotherapy-resistant tumor.

Dosimetric assessment of patient dose calculation on a deep learning-based synthesized computed tomography image for adaptive radiotherapy

Purpose

Dose computation using cone beam computed tomography (CBCT) images is inaccurate for the purpose of adaptive treatment planning. The main goal of this study is to assess the dosimetric accuracy of synthetic computed tomography (CT)‐based calculation for adaptive planning in the upper abdominal region. We hypothesized that deep learning‐based synthetically generated CT images will produce comparable results to a deformed CT (CTdef) in terms of dose calculation, while displaying a more accurate representation of the daily anatomy and therefore superior dosimetric accuracy.

Methods

We have implemented a cycle‐consistent generative adversarial networks (CycleGANs) architecture to synthesize CT images from the daily acquired CBCT image with minimal error. CBCT and CT images from 17 liver stereotactic body radiation therapy (SBRT) patients were used to train, test, and validate the algorithm.

Results

The synthetically generated images showed increased signal‐to‐noise ratio, contrast resolution, and reduced root mean square error, mean absolute error, noise, and artifact severity. Superior edge matching, sharpness, and preservation of anatomical structures from the CBCT images were observed for the synthetic images when compared to the CTdef registration method. Three verification plans (CBCT, CTdef, and synthetic) were created from the original treatment plan and dose volume histogram (DVH) statistics were calculated. The synthetic‐based calculation shows comparatively similar results to the CTdef‐based calculation with a maximum mean deviation of 1.5%.

Conclusions

Our findings show that CycleGANs can produce reliable synthetic images for the adaptive delivery framework. Dose calculations can be performed on synthetic images with minimal error. Additionally, enhanced image quality should translate into better daily alignment, increasing treatment delivery accuracy.

Readability of Patient Education Materials From High-Impact Medical Journals: A 20-Year Analysis

Comprehensive patient education is necessary for shared decision-making. While patient–provider conversations primarily drive patient education, patients also use published materials to enhance their understanding. In this investigation, we evaluated the readability of 2585 patient education materials published in high-impact medical journals from 1998 to 2018 and compared our findings to readability recommendations from national groups. For all materials, mean readability grade levels ranged from 11.2 to 13.8 by various metrics. Fifty-four (2.1%) materials met the American Medical Association recommendation of sixth grade reading level, and 215 (8.2%) met the National Institutes of Health recommendation of eighth grade level. When stratified by journal and material type, general medical education materials from Annals of Internal Medicine were the most readable (P < .001), with 79.8% meeting the eighth grade level. Readability did not differ significantly over time. Efforts to standardize publication practice with the incorporation of readability evaluation during the review process may improve patients’ understanding of their disease processes and treatment options.

Radiotherapy for locally advanced pancreatic ductal adenocarcinoma

Locally advanced, unresectable pancreatic ductal adenocarcinoma has a poor prognosis with a median overall survival of 10-16 months. It is defined by tumor involvement of neighboring blood vessels that precludes resection. Standard doses of conventionally fractionated radiation have had little effect on overall survival in this setting, although they are associated with improved progression-free survival and time off chemotherapy. Evolving radiotherapy techniques have allowed for higher, ablative doses of radiotherapy to target tumor while also respecting normal tissue constraints of neighboring radiosensitive structures in the gastrointestinal tract. Moreover, advancements in image guidance, organ motion management, and the use of adaptive planning have enabled safe delivery of higher, ablative doses of radiation. This has resulted in improved survival. This review will summarize the expanding role of radiotherapy in the management of locally advanced, unresectable pancreatic cancer.

Assessment of Use, Specificity, and Readability of Written Clinical Informed Consent Forms for Patients With Cancer Undergoing Radiotherapy

Importance

Appropriate informed consent processes are crucial to preservation of patient autonomy and shared decision making. Although half of patients with cancer receive radiotherapy, it is unknown whether current consent practices are comprehensible for patients.

Objective

To characterize use, specificity, and readability of clinical informed consent forms for radiotherapy, hypothesizing that forms would be higher than the recommended sixth- to eighth-grade readability level.

Design, Setting, and Participants

This nationwide cross-sectional survey study and readability analysis was conducted from 2016 to 2018 and included 89 academic radiation oncology departments that were part of the 2016 Electronic Residency Application Service. Department leaders (clinical directors, chairs, and personal contacts of study authors) at academic radiation oncology departments were contacted via email.

Main Outcomes and Measures

Readability levels were measured by 7 validated readability indices, including the Ford, Caylor, Sticht (FORCAST) index for nonnarrative texts. Difficult words were identified using The Living Word Vocabulary, which describes the readability grade levels of 40 000 common words.

Results

Of 89 departments, 67 (75%) responded to questions and 57 (64%) provided 113 forms for analysis. Departments providing forms did not differ substantially from others in terms of region, residency size, research output, rural vs urban location, or public vs private institution status. All departments obtained patient written informed consent before radiotherapy; 38 (57%) used body site-specific forms. Using the most conservative (low-score) estimate, mean form readability ranged from grade level 10.6 to 14.2. By 7 distinct indices, only 9 (8%) of 113 forms met the recommended eighth-grade readability level, and 4 (4%) forms met a sixth-grade level. Not a single form met either recommendation based on the FORCAST index. Forms used an average of 7.2 difficult words. Body site-specific forms had considerably better readability than general consent forms.

Conclusions and Relevance

This nationwide study of informed consent practices for cancer treatment with radiotherapy demonstrates that while all US academic radiotherapy departments use written consent forms, it is rare for templates to meet the recommended readability levels for patient materials. These data suggest the need for reevaluation and modification of the approach to radiotherapy consent, ideally with guidance and templates designed by national professional organizations.

Elevation of Serum CEA in Patients with Squamous Cell Carcinoma of the Anus

The proportion of anal cancer cases that produce elevated carcinoembryonic antigen (CEA) levels is not well described in the medical literature. In this study, we used electronic health record data from a single urban cancer center to identify patients from 2004-2018 with anal cancer who have also had a pre-initial treatment CEA measurement. We identified 40 patients who met our eligibility criteria. Of those, 11 (27.5%) had an elevated pretreatment CEA. Elevated CEA was not associated with any of the clinical or demographic covariates; however, three out of five patients with a recurrence had an elevated CEA.

A Single-Institution Experience in the Preoperative Selection of DCIS Patients for IORT using the ASTRO Consensus Guidelines

Purpose

Intraoperative radiation therapy (IORT) as a form of accelerated partial breast irradiation (APBI) is controversial given the limited evidence to support its efficacy. However, it remains an attractive option for low-risk patients with ductal carcinoma in situ (DCIS), who derive a small absolute benefit in local control with standard whole breast irradiation (WBI). We examine how the American Society for Therapeutic Radiation Oncology (ASTRO) APBI consensus guidelines (CG) may be applied to the preoperative selection of patients with DCIS for IORT and determine treatment outcomes by CG group.

Methods and Materials

We identified patients with biopsy-proven pure DCIS enrolled in an institutional prospective registry IORT database using the Zeiss Intrabeam^® device between September 2013 and February 2017. Based on available preoperative clinicopathologic information, patients were deemed suitable, cautionary, or unsuitable for IORT according to the ASTRO CG. Change in CG group based on final pathologic diagnosis was determined, and additional therapy was recommended for unsuitable patients. Outcome in terms of ipsilateral breast tumor recurrence was determined.

Results

A total of 61 DCIS lesions in 60 patients were treated with IORT. Preoperatively, 21 patients (35%) were suitable and 36 (59%) were cautionary. Four (6%) were unsuitable because of lesion size but declined WBI. Final pathologic diagnosis changed the CG grouping of 10 patients (16%) because of either occult high-grade disease in 2 (3%) or close/positive margins in 8 (13%). Ultimately 12 patients total were considered unsuitable, of whom 8 (66%) accepted additional WBI after IORT. At a median follow-up of 2.2 years, ipsilateral breast tumor recurrence was identified among 2 suitable, 1 cautionary, and no unsuitable patients.

Conclusion

Further investigation is necessary to refine selection of patients with DCIS who may be optimally treated with IORT alone. High acceptance of additional therapy among unsuitable patients resulted in excellent outcomes. The use of biomarkers in addition to traditional clinical and pathologic factors may help to better select patients for IORT.

Abstract B51: Quantitative multiplex immunofluorescence reveals that chemoradiation therapy favorably modulates the tumor immune microenvironment of pancreatic cancer

Immunotherapy has altered the therapeutic landscape in several malignancies but to date has not been effective in treatment of pancreatic ductal adenocarcinoma (PDAC). Patients with advanced PDAC continue to have median survival under one year and thus new therapeutic approaches for this daunting disease are urgently needed. It is well known that radiation therapy causes the release of tumor antigens and pro-inflammatory cytokines leading to stimulation of anti-tumor immunity. In our study, we sought to quantify this effect by comparing immune cell infiltration in tissues of PDAC treated with chemoradiation to untreated tumors.

Slides obtained from surgical resection specimens were stained using quantitative multiplex immunofluorescence (qmIF) for: CD3, CD4, CD8, FOXP3, CD68, and Ki-67. Nuclei were labeled using DAPI. Slides with tumor tissue were then imaged (15-20 images per slide) using automated imaging system VECTRA and they were analyzed using inForm software to evaluate cell density in tumor and stroma compartments. Overall, slides were obtained and analyzed from 6 different patients who underwent chemoradiation therapy and from 5 patients who did not receive neoadjuvant treatment.

When comparing treated vs. untreated tumors, CD3+ densities were significantly higher in the stromal tissue of the treated tumors vs. untreated tumors (P = 0.0095). CD3+CD4+FOXP3- T helper cells were similarly significantly higher in treated tumors (P = 0.0095), while there was a trend towards increase in CD3+CD8+ cytotoxic T cells (P = 0.0667). Conversely, CD4+FOXP3+ cells were increased in untreated tumors although significance was not reached (P = 0.15). No clear differences in infiltrating CD68+ macrophages were observed between treated and untreated tumors.

To our knowledge this is the first time that immune cell infiltrates of PDAC were characterized using qmIF. The higher counts of CD3+CD4+ T helper cells and of CD3+CD8+ cytotoxic T cells found in tumors treated with chemoradiation can be explained by the increased immunogenicity caused by treatment. A tendency towards a higher density of CD4+FOXP3+ cells in untreated tumors may contribute to immunosuppression in the tumor microenvironment as there were less CD3+CD8+ cytotoxic T cells and CD3+CD4+ T helper cells found in those tumors.

We are in the process of collecting and staining additional samples to build on these findings. We will correlate our data with survival data to identify biomarkers predictive of outcome and provide rationale for the development of new treatment strategies for this challenging disease.

Citation Format: Thomas Enzler, Robyn Gartrell, Ladan Fazlollahi, Subha Perni, Pan Kim, Thomas Hart, Christian Monsalve, Samuel Green, Yvonne Saenger, David P. Horowitz. Quantitative multiplex immunofluorescence reveals that chemoradiation therapy favorably modulates the tumor immune microenvironment of pancreatic cancer [abstract]. In: Proceedings of the AACR Special Conference on Tumor Immunology and Immunotherapy; 2017 Oct 1-4; Boston, MA. Philadelphia (PA): AACR; Cancer Immunol Res 2018;6(9 Suppl):Abstract nr B51.

Mucosal Melanoma: New Insights and Therapeutic Options for a Unique and Aggressive Disease

Mucosal melanoma is a rare disease that is distinct from melanomas arising at other sites in the body. While melanocytes are most abundant in the skin, they can be found in smaller numbers in the mucous membranes, as well as in the eye. There are epidemiologic, genetic, and other physiologic differences between melanomas arising from melanocytes at these various sites, and these differences have important implications for both disease prognosis and treatment. Here, we review the features of mucosal melanoma that distinguish it from melanomas arising at other sites, and we highlight recent biological discoveries and emerging treatment options for this aggressive disease.

Evaluation of Partial Breast Reirradiation with Intraoperative Radiotherapy after Prior Thoracic Radiation: A Single-Institution Report of Outcomes and Toxicity

INTRODUCTION

Mastectomy is the current standard of care for ipsilateral breast tumor recurrences after prior whole breast irradiation (WBI). We report our single-institution experience with breast-conserving surgery (BCS) followed by intraoperative radiotherapy (IORT) as an alternative to salvage mastectomy for new or recurrent breast cancers that develop in the setting of prior thoracic radiation.

METHODS

We performed an IRB-approved retrospective review of patients treated with breast IORT between September 2013 and November 2016. We identified 12 patients who declined salvage mastectomy for their breast cancer after prior thoracic radiation. IORT was delivered using the Intrabeam™ device (Carl Zeiss, Germany). A dose of 20 Gy was prescribed to the lumpectomy cavity surface using 50 kV X-rays. We graded both acute and late treatment-related breast toxicities using the National Cancer Institute Common Terminology Criteria for Adverse Events version 4.0. Local control, mastectomy-free survival, distant metastasis, and overall survival were determined.

RESULTS

Our study included nine patients who developed a new or recurrent ipsilateral breast cancer after prior WBI for early-stage breast cancer, two patients with primary breast cancer after mantle-field radiation for Hodgkin's lymphoma, and one patient with a synchronous stage III non-small cell lung cancer treated with definitive radiation to the ipsilateral lung and mediastinum. The median time from prior radiation to presentation was 18 years (range: 2 months to 46 years). All patients successfully underwent partial breast reirradiation with IORT and were able to preserve their breast. At a median follow-up of 14 months (4-25 months), there were no local or distant recurrences. There was a single non-cancer-related death. In the acute setting, we observed grade 1 toxicity in 58% (n = 7), grade 2 toxicity in 17% (n = 2), and no grade 3 or higher toxicity. In the late setting, at least 3 months after IORT, we observed grade 1 hyperpigmentation and/or fibrosis in 50% (n = 6), symptomatic seroma requiring drainage in 33% (n = 4). A single patient developed an abscess requiring hospitalization and intravenous antibiotic therapy.

CONCLUSION

BCS with IORT is a feasible salvage option for patients who present with localized breast cancer after prior thoracic radiation treatment. Continued follow-up of these patients is warranted given the incidence of delayed toxicity.

Gamma Knife treatment of recurrent CNS metastases of pancreatic origin: a case report and review of the literature

Brain metastases (BM) of pancreatic origin are extremely rare. We review the literature around BM of pancreatic origin and describe a 38-year-old woman who developed BM 10 months after pancreaticoduodenectomy for treatment of pancreatic adenocarcinoma. She underwent resection and fractionated stereotactic radiotherapy followed by re-resection and Gamma Knife radiosurgery (GKRS) when the lesion recurred. She then developed two new BM, and was treated with GKRS. The patient is alive without progression 38 months after her most recent GKRS.

Stereotactic body radiotherapy for the pancreas: a critical review for the medical oncologist

With recent advances in imaging modalities and radiation therapy, stereotactic body radiotherapy (SBRT) has allowed for the delivery of high doses of radiation with accuracy and precision. As such, SBRT has generated favorable results in the treatment of several cancers. Although the role of radiation has been controversial for the treatment of pancreatic ductal adenocarcinoma (PDAC) due to rather lackluster results in clinical trials, SBRT may offer improved outcomes, enhance the quality of life, and aid in palliative care settings for PDAC patients. This review delineates the role of SBRT in the treatment of PDAC, presents the defining principles of radiation biology and the radiation oncology work flow, and discusses the prospects of new treatment regimens involving tumor immunology and radiation therapy.

De-escalation of radiation dose for human papillomavirus-positive oropharyngeal head and neck squamous cell carcinoma: A case report and preclinical and clinical literature review

Traditionally, head and neck squamous cell carcinoma (HNSCC) has been considered to be a relatively homogeneous disease. However, recent data have demonstrated that human papillomavirus (HPV)-positive and HPV-negative disease are two different clinical entities associated with different outcomes. Preclinical and clinical studies have reported a divergence in treatment strategies as well as prognostic outcomes for HNSCCs that are HPV-positive versus HPV-negative. The present study describes the case of a 52-year-old man who presented with stage IVB cT2N3M0 right tonsillar HPV-positive squamous cell carcinoma. Induction chemotherapy with docetaxel, cisplatin and 5-fluorouracil (TPF), followed by chemoradiation therapy with carboplatin and 70 Gray (Gy) radiation in daily fractions was recommended. The patient completed the TPF and carboplatin treatment; however, he was unable to tolerate the radiation course, receiving a final dose of 46 Gy. A 60-day follow-up right neck salvage dissection was subsequently performed. Despite having received a partial radiation treatment of 46 Gy, the patient had no pathological evidence of disease at 60 days post radiation treatment. Repeat positron emission tomography-computed tomography at 32 months after the right neck dissection revealed no evidence of disease. The present study also discusses the current preclinical in vitro and in vivo targets for HPV-positive HNSCC and the obstacles presented in advancing clinical treatment modalities. Previous preclinical models investigating radiation sensitivity have yielded mixed results. Thus, it is important to understand and establish representative preclinical models for studying HPV and HNSCC to improve clinical research and therapeutic development. This review may guide future understanding of the role of HPV in HNSCC.

Higher locoregional recurrence rate for triple-negative breast cancer following neoadjuvant chemotherapy, surgery and radiotherapy

Background

Breast cancer subtype, determined by expression of estrogen/progesterone receptor (ER/PR) and human epidermal growth factor receptor (HER)-2, is predictive for prognosis. The importance of subtype to locoregional recurrence (LRR) following neoadjuvant chemotherapy (NAC) is unknown, particularly after adjuvant radiotherapy (RT).

Methods

We retrospectively identified 160-breast cancer patients registered at Columbia University Medical Center from 1999 to 2012 treated with NAC, surgery and adjuvant RT.

Results

Patients were grouped by receptor status: hormone receptor positive (HR+) [(ER or PR+)/HER2−; n = 75], HER2+ (n = 46), or triple-negative (TNBC) [ER (−) PR (−) HER2 (−); n = 36]. The median follow-up was 28 months. 92.0% received an anthracycline-taxane based NAC and 80.4% of HER2+ patients received trastuzumab. All underwent surgical resection followed by RT. 15.6% had a pathologic complete response (pCR): 26% of HER2+, 5% of HR+, and 25% of TN. The actuarial rate of DM was 13.8% for the entire cohort, with equivalent rates by subtypes in non-pCR patients. The overall rate of LRR was 8%. However, the LRR rate was significantly higher for TNBC patients (22.2%) than HER2+ (5.6%) (p = 0.025) or HR+ (3.0%) (p = 0.037) in non-pCR group. In the pCR group, two patients had recurrence; one LRR and one a DM, both had TNBC. All LRR occurred in or near the radiation field.

Conclusions

TNBC patients with < pCR to NAC have a significantly higher LRR rate as compared to other subtypes even with surgery and adjuvant RT. Our data support a need to further intensify local therapy in TNBC patients.

Fetal radiation monitoring and dose minimization during intensity modulated radiation therapy for glioblastoma in pregnancy

We examined the fetal dose from irradiation of glioblastoma during pregnancy using intensity modulated radiation therapy (IMRT), and describe fetal dose minimization using mobile shielding devices. A case report is described of a pregnant woman with glioblastoma who was treated during the third trimester of gestation with 60 Gy of radiation delivered via a 6 MV photon IMRT plan. Fetal dose without shielding was estimated using an anthropomorphic phantom with ion chamber and diode measurements. Clinical fetal dose with shielding was determined with optically stimulated luminescent dosimeters and ion chamber. Clinical target volume (CTV) and planning target volume (PTV) coverage was 100 and 98 % receiving 95 % of the prescription dose, respectively. Normal tissue tolerances were kept below quantitative analysis of normal tissue effects in the clinic (QUANTEC) recommendations. Without shielding, anthropomorphic phantom measurements showed a cumulative fetal dose of 0.024 Gy. In vivo measurements with shielding in place demonstrated a cumulative fetal dose of 0.016 Gy. The fetal dose estimated without shielding was 0.04 % and with shielding was 0.026 % of the target dose. In vivo estimation of dose equivalent received by the fetus was 24.21 mSv. Using modern techniques, brain irradiation can be delivered to pregnant patients in the third trimester with very low measured doses to the fetus, without compromising target coverage or normal tissue dose constraints. Fetal dose can further be reduced with the use of shielding devices, in keeping with the principle of as low as reasonably achievable.

P3-13-11: Survival Benefit Associated with Post-Mastectomy Radiation for Node-Positive, Intermediate-Risk Breast Cancer Patients: Results of a Study from the SEER Registry Data

Background

The role of post-mastectomy radiation therapy (PMRT) for breast cancer patients with intermediate-risk (1-3 positive nodes) disease remains controversial. This Surveillance, Epidemiology, and End Results (SEER) study investigated the impact of PMRT in the intermediate-risk breast cancer patient population on cause-specific survival (CSS) and overall survival (OS). The study also investigated the impact of estrogen receptor (ER) status, which has been reported in the SEER database since 2004, on the impact of PMRT in this patient population on CSS and OS.

Methods: The SEER database was used to identify all breast cancer patients who were treated between 2004–2007, who had undergone mastectomy, and who had T1-2 tumors and 1–3 pathologically positive lymph nodes. The status of radiation therapy, ethnicity, tumor grade, TNM stage, year of diagnosis, number of LNs sampled, number of LNs positive, and estrogen/progesterone receptor status was recorded. Patients missing pathologic or treatment-related information were excluded. Statistical analysis for CSS and OS was performed using the Kaplan-Meier method and analyzed using the log-rank test. Multivariable analysis was performed using the Cox proportional hazards regression model. Statistical analyses were performed using PASW, version 18.

Results: 10,517 patients were identified, with a median follow-up of 21.8 months (range 0–47 months). 2339 patients (22.2%) received PMRT. Younger patients, increasing tumor size, increasing tumor grade, and ER negative tumors were more likely to receive PMRT. PMRT was associated with improved OS, 92.8% (95% CI 91.294.4%) versus 88.7% (95% CI 87.7−89.7%), p &lt; 0.001. However, there was no overall CSS benefit to PMRT, p = 0.197. In the subgroup with ER positive tumors, PMRT was associated with both improved OS, 95.5% (95% CI 93.9−97.1%) versus 91.0% (95% CI 90.0−92.0%), p &lt; 0.001, and improved CSS, 97.6% (95% CI 96.6−98.8%) versus 96.1% (95% CI 95.3−96.9%), p = 0.009. Multivariate analysis showed that PMRT was significantly associated with improved survival (HR 0.744, p = 0.011); increasing age, tumor grade, ER negative tumors, increasing tumor stage, and increasing positive nodal ratio were associated with increased risk of death.

Conclusion: Patients with intermediate risk breast cancer who received PMRT have improved OS compared to those who did not receive PMRT. For patients with ER positive tumors, PMRT also appears to be associated with improved CSS. Greater consideration for post-mastectomy radiation therapy use may be warranted for this patient population.

Adjuvant chemoradiation therapy after pancreaticoduodenectomy in elderly patients with pancreatic adenocarcinoma

PURPOSE

To evaluate the efficacy of adjuvant chemoradiation therapy (CRT) for pancreatic adenocarcinoma patients ≥ 75 years of age.

METHODS

The study group of 655 patients underwent pancreaticoduodenectomy (PD) for pancreatic adenocarcinoma at the Johns Hopkins Hospital over a 12-year period (8/30/1993 to 2/28/2005). Demographic characteristics, comorbidities, intraoperative data, pathology data, and patient outcomes were collected and analyzed by adjuvant treatment status and age ≥ 75 years. Cox proportional hazards analysis determined clinical predictors of mortality and morbidity.

RESULTS

We identified 166 of 655 (25.3%) patients were ≥ 75 years of age and 489 of 655 patients (74.7%) were <75 years of age. Forty-nine patients in the elderly group (29.5%) received adjuvant CRT. For elderly patients, node-positive metastases (p = 0.008), poor/anaplastic differentiation (p = 0.012), and undergoing a total pancreatectomy (p = 0.010) predicted poor survival. The 2-year survival for elderly patients receiving adjuvant therapy was improved compared with surgery alone (49.0% vs. 31.6%, p = 0.013); however, 5-year survival was similar (11.7% vs. 19.8%, respectively, p = 0.310). After adjusting for major confounders, adjuvant therapy in elderly patients had a protective effect with respect to 2-year survival (relative risk [RR] 0.58, p = 0.044), but not 5-year survival (RR 0.80, p = 0.258). Among the nonelderly, CRT was significantly associated with 2-year survival (RR 0.60, p < 0.001) and 5-year survival (RR 0.69, p < 0.001), after adjusting for confounders.

CONCLUSIONS

Adjuvant therapy after PD is significantly associated with increased 2-year but not 5-year survival in elderly patients. Additional studies are needed to select which elderly patients are likely to benefit from adjuvant CRT.

Deficiency of Bloom syndrome helicase activity is radiomimetic

Bloom syndrome is caused by homozygous mutations in BLM, which encodes a RecQ DNA helicase. Patient-derived cells deficient in BLM helicase activity exhibit genetic instability--apparent cytogenetically as sister chromatid exchanges--and activated DNA damage signaling. In this report, we show that BLM-knockout colorectal cancer cells exhibited endogenous, ATM-dependent double-strand DNA break responses similar to those recently observed in Bloom syndrome patient-derived cells. Xenograft tumors established from BLM-deficient cancer cells were not radiosensitive, but exhibited growth impairment that was comparable to that of wild type tumors treated with a single, high dose of ionizing radiation. These results suggest that pharmacological inhibitors of BLM would have a radiomimetic effect and that transient inhibition of BLM activity might be a viable strategy for anticancer therapy.