Phase 1 Study of Hypofractionated Proton Beam Radiation Therapy in Adjuvant Pancreatic Cancer (PROTON-PANC)

PURPOSE

Despite improvement in systemic therapy, patients with pancreatic ductal adenocarcinoma (PDAC) frequently experience local recurrence. We sought to determine the safety of hypofractionated proton beam radiation therapy (PBT) during adjuvant chemotherapy.

METHODS AND MATERIALS

Nine patients were enrolled in a single-institution phase 1 trial (NCT03885284) between 2019 and 2022. Patients had PDAC of the pancreatic head and underwent R0 or R1 resection and adjuvant modified FOLFIRINOX (mFFX) chemotherapy. The primary endpoint was to determine the dosing schedule of adjuvant PBT (5 Gy × 5 fractions) using limited treatment volumes given between cycles 6 and 7 of mFFX. Patients received PBT on days 15 to 19 in a 28-day cycle before starting cycle 7 (dose level 1, DL1) or on days 8 to 12 in a 21-day cycle before starting cycle 7 (DL2).

RESULTS

The median patient age was 66 years (range, 52-78), and the follow-up time from mFFX initiation was 12.5 months (range, 6.2-37.4 months). No patients received preoperative therapy. Four had R1 resections and 5 had node-positive disease. Three patients were enrolled on DL1 and 6 patients on DL2. One dose-limiting toxicity (DLT) occurred at DL2 (prolonged grade 3 neutropenia resulting in discontinuation of mFFX after cycle 7). No other DLTs were observed. Four patients completed 12 cycles of mFFX (range, 7-12; median, 11). No patients have had local recurrence. Five of 9 patients had recurrence: 3 in the liver, 1 in the peritoneum, and 1 in the bone. Six patients are still alive, 4 of whom are recurrence-free. The median time to recurrence was 12 months (95% CI, 4 to not reached [NR]), and median overall survival was NR (95% CI, 6 to NR; 2-year survival rate, 57%).

CONCLUSIONS

PBT integrated within adjuvant mFFX was well tolerated, and no local recurrence was observed. These findings warrant further exploration in a phase 2 trial.

Hypofractionated Intensity Modulated Proton Therapy (IMPT) and Systemic Therapy for Unresectable Hepatobiliary Cancers

PURPOSE/OBJECTIVE(S)

Proton therapy offers significantly reduced normal liver dose compared to photon therapy for liver tumors, and therefore has the potential for dose escalation and hypofractionation. Employing IMPT, we have initiated a hypofractionated treatment regimen for unresectable liver cancer at a single academic institution. Here we report our initial results on dosimetry and clinical outcomes of hypofractionated IMPT for unresectable hepatocellular carcinoma (HCC) and cholangiocarcomas (CC).

MATERIALS/METHODS

We retrospectively reviewed records of consecutive patients treated with IMPT for CC and HCC from 2018 to 2021. Inverse treatment planning with robust optimization, daily image guidance, pencil beam scanning dose delivery were used for all patients. Motion management included 4D-CT and abdominal compression. Toxicity was graded using the Common Terminology Criteria for Adverse Events version 5.0 and survival was calculated using the Kaplan Meier method.

RESULTS

We identified 15 patients (3 HCC, 4 intrahepatic CC, 8 hilar CC) treated with IMPT to a median dose of 5805 cGy (range, 4500 - 6000 cGy) in 15 fractions. Two had metastatic and 13 had regional disease. Median tumor volume was 91.5 cc (range, 10.92 - 366.31 cc). Prior therapies included: 12 patients received upfront chemotherapy, (gemcitabine plus cisplatin most common), 4 received prior surgery on the liver, and 5 received prior liver directed treatment. With a median follow up of 10 months, the median overall survival (OS) and 1-year OS was 18.7 months and 76% respectively. One patient underwent resection and 1 patient received liver transplant; 7 (47%) patients had disease progression (3 local, 1 regional lymph node, 4 elsewhere liver, 5 distant metastatic). Five patients with CC developed grade 3 toxicity in the form of cholangitis (4) and hemobilia (1). Of these patients, 4 patients were of the hilar type.

CONCLUSION

Our early results using hypofractionated IMPT for unresectable HCC and CC resulted in encouraging local control rates with an acceptable toxicity profile. Further study is warranted to determine the optimal liver directed therapy for this challenging patient population.

Radical excision for retroperitoneal soft tissue sarcoma: A national propensity-matched outcomes analysis

BACKGROUND

Given the rarity of retroperitoneal soft tissue sarcoma, few studies have assessed if radical excision of retroperitoneal soft tissue sarcoma with adjacent organs improves survival outcomes. This propensity score-matched study aimed to evaluate the impact of radical excision versus resection of tumor alone.

METHODS

The National Cancer Database 2004 to 2015 was used to assess short- and long-term outcomes of resection of tumor alone versus radical excision (tumor plus ≥1 adjacent organs) via 1:1 propensity-matched analyses. Subgroup analyses included low-grade, high-grade, liposarcoma, leiomyosarcoma, adjacent organ involvement alone, localized tumors alone, and high-volume hospitals (≥10 resections/y). Multivariable logistic regression models identified factors associated with radical excision.

RESULTS

Comparison of propensity-matched groups (N = 1,139/group) revealed no significant differences in 30-day mortality, 90-day mortality, or overall survival (for all, P > .580). For all subgroup analyses comparing resection of tumor alone with radical excision, including localized tumors without organ invasion (N = 208/group), there were no identified differences in short- or long-term survival. Although it yielded lower R2 resection rates (P = .007), radical excision was associated with greater mean length of stay (P < .001).

CONCLUSION

Radical excision was not associated with improved retroperitoneal soft tissue sarcoma survival irrespective of grade, histology, hospital volume, or adjacent organ involvement. Resection of ostensibly involved adjacent viscera may increase morbidity without survival benefit. These results inform ongoing discussion regarding histology-tailored, situation-specific extent of retroperitoneal soft tissue sarcoma resections.

Ethnicity and insurance status predict metastatic disease presentation in prostate, breast, and non-small cell lung cancer

Background

Ethnicity and insurance status have been shown to impact odds of presenting with metastatic cancer, however, the interaction of these two predictors is not well understood. We evaluate the difference in odds of presenting with metastatic disease in minorities compared to white patients despite access to the same insurance across three common cancer types.

Methods

Using the National Cancer Database, a multilevel logistic regression model that estimated the odds of metastatic disease was fit, adjusting for covariates including year of diagnosis, ethnicity, insurance, income, and region. We included adults diagnosed with metastatic prostate, non–small cell lung cancer (NSCLC), and breast cancer from 2004 to 2015.

Results

The study cohort consisted of 1 191 241 prostate cancer (PCa), 1 310 986 breast cancer (BCa), and 1 183 029 NSCLC patients. Private insurance was the most protective factor against metastatic presentation. Odds of presenting with metastatic disease were 0.190 [95% CI, 0.182‐0.198], 0.616 [95% CI, 0.602‐0.630], and 0.270 [95% CI, 0.260‐0.279] for PCa, NSCLC, and BCa compared to uninsured patients, respectively. Private insurance provided the most significant benefit to non‐Hispanic White PCa patients with 81% reduction in odds of metastatic presentation and conferred the least benefit to African‐American NSCLC patients at 30.4% reduction in odds of metastatic presentation.

Conclusions

Insurance status provided the single most protective effect against metastatic presentation. This benefit varied for minorities despite similar insurance. Reducing metastatic disease presentation rates requires addressing social barriers to care independent of insurance.

Early Experience of the First Single-Room Gantry Mounted Active Scanning Proton Therapy System at an Integrated Cancer Center

Introduction: Review the early experience with a single-room gantry mounted active scanning proton therapy system.

Material and Methods: All patients treated with proton beam radiotherapy (PBT) were enrolled in an institutional review board-approved patient registry. Proton beam radiotherapy was delivered with a 250 MeV gantry mounted synchrocyclotron in a single-room integrated facility within the pre-existing cancer center. Demographic data, cancer diagnoses, treatment technique, and geographic patterns were obtained for all patients. Treatment plans were evaluated for mixed modality therapy. Insurance approval data was collected for all patients treated with PBT.

Results: A total of 132 patients were treated with PBT between March 2018 and June 2019. The most common oncologic subsites treated included the central nervous system (22%), gastrointestinal tract (20%), and genitourinary tract (20%). The most common histologies treated included prostate adenocarcinoma (19%), non-small cell lung cancer (10%), primary CNS gliomas (8%), and esophageal cancer (8%). Rationale for PBT treatment included limitation of dose to adjacent critical organs at risk (67%), reirradiation (19%), and patient comorbidities (11%). Patients received at least one x-ray fraction delivered as prescribed (36%) or less commonly due to unplanned machine downtime (34%). Concurrent systemic therapy was administered to 57 patients (43%). Twenty-six patients (20%) were initially denied insurance coverage and required peer-to-peers (65%), written appeals (12%), secondary insurance approval (12%), and comparison x-ray to proton plans (8%) for subsequent approval. Proton beam radiotherapy approval required a median of 17 days from insurance submission.

Discussion: Incorporation of PBT into our existing cancer center allowed for multidisciplinary oncologic treatment of a diverse population of patients. Insurance coverage for PBT presents as a significant hurdle and improvements are needed to provide more timely access to necessary oncologic care.

Variations in Retroperitoneal Soft Tissue Sarcoma Outcomes by Hospital Type: A National Cancer Database Analysis

PURPOSE

Surgical resection remains the cornerstone of retroperitoneal soft tissue sarcoma (RPS) treatment. Patient- and sarcoma-related factors are well known to influence survival outcomes. The effect of hospital-related factors on long-term survival, however, are not well understood. We sought to assess the relative contribution of hospital-level factors to mortality after surgical treatment of RPS.

METHODS AND MATERIALS

The 2004-2015 National Cancer Database was used to identify 10,113 patients who underwent surgical treatment of RPS. Patient-, sarcoma-, hospital-, and treatment-level factors were compared by increasing survival times. Stepwise multivariable Cox regression was performed that controlled for covariates to measure the relative contributions of these factors on overall survival (OS). Effect modification analyses ascertained how hospital type modulates the volume relationship with respect to RPS mortality.

RESULTS

Factors predictive of worsening OS were older age, nonprivate insurance, low income, presence of comorbidities, tumor histology, high grade or stage, and R2 resection (for all, P < .05). Increasing hospital surgical volume predicted decreasing risk of death across all survival times. However, analysis by hospital type demonstrated that compared with academic centers, the risk of death at community centers increased significantly as surgical volume increased (hazard ratio, 1.26; 95% CI, 1.03 to 1.53).

CONCLUSION

Hospital factors affect mortality after surgical treatment of RPS. Specifically, hospital type alters the surgical volume-outcome relationship for RPS mortality such that community centers perform worse with increasing volumes. Recommendations that higher surgical volume improves outcomes cannot be applied universally and must be re-examined in other complex surgical cancers.

Regionalization of Retroperitoneal Sarcoma Surgery to High-Volume Hospitals: Missed Opportunities for Outcome Improvement

PURPOSE:

Surgery continues to be the dominant therapy for the management of retroperitoneal soft-tissue sarcoma (RPS). Many groups advocate performing these resections at high-volume hospitals (HVHs), given their complexity. We therefore sought to explore whether RPS surgery has indeed begun to regionalize to HVHs in the same manner as pancreatic cancer (PC) surgery during the last decade.

METHODS:

We identified 70,763 patients who underwent surgical resection for RPS or PC using the National Cancer Database (2004 to 2015). Patients were stratified by hospital surgical volume. We performed an adjusted time trend analysis to compare trends in performance of surgery at HVHs for RPS versus PC. Multivariable logistic analyses were then performed, controlling for covariables, to elucidate relationships between patient-, hospital-, and treatment-related variables that may contribute to these observed trends.

RESULTS:

Only 9.6% of patients underwent RPS surgery at HVHs. During this time period, the odds ratio of undergoing RPS compared with pancreatectomy at HVHs was 0.65 ( P < .05). Time trend analysis estimated that whereas both procedures are regionalizing, the rate of RPS regionalization grew at 30.5% of the rate of PC (1.017 v 1.056; P < .001) and remained consistent after using several hospital volume thresholds and hospital volume as a continuous variable.

CONCLUSION:

Results from this retrospective multi-institutional analysis uncovered a lag in the regionalization of surgery for RPS compared with PC surgery. These findings reinforce the call to regionalize surgery for RPS to HVHs in a manner that is similar to that of other procedures in complex cancer surgery.

Social determinants of stage IV anal cancer and the impact of pelvic radiotherapy in the metastatic setting

Anal cancer is a relatively rare malignancy, and a minority of patients present with metastatic disease in the United States. The National Cancer Database (NCDB) was used to identify factors associated with metastatic disease at presentation and evaluate the role of pelvic radiotherapy in these patients. The NCDB was queried for patients with squamous cell cancer of the anus diagnosed between 2004 and 2013. Patients were stratified by clinical stage at diagnosis, and a binary logistic regression model was created to identify factors associated with metastatic disease at diagnosis. A secondary metastatic cohort was generated and a multivariable Cox proportional hazards model was created to identify factors associated with improved survival. To validate findings, propensity-score matching was performed to generate a 1:1 paired dataset stratified by receipt of pelvic radiotherapy. The primary analysis cohort consisted of 28,500 patients. Facility location, male gender, and lack of insurance were confirmed as independent risk factors for metastatic disease. The metastatic cohort consisted of 1264 patients. Multivariable analysis confirmed female sex, possession of a private or Medicare insurance plan, pelvic radiotherapy, and chemotherapy as independent predictors of improved survival. A propensity-score matched cohort of 730 patients was generated. The median survival was 17.6 months in patients who received radiotherapy versus 14.5 months in those who did not (P < 0.01). In this cohort, male gender and lack of insurance were associated with metastatic disease at presentation. Furthermore, a significant benefit was associated with the use of pelvic radiotherapy. Future prospective research is warranted to confirm these findings.

Gastric Adenocarcinoma: A Multimodal Approach

Despite its declining incidence, gastric cancer (GC) remains a leading cause of cancer-related deaths worldwide. A multimodal approach to GC is critical to ensure optimal patient outcomes. Pretherapy fine resolution contrast-enhanced cross-sectional imaging, endoscopic ultrasound and staging laparoscopy play an important role in patients with newly diagnosed ostensibly operable GC to avoid unnecessary non-therapeutic laparotomies. Currently, margin negative gastrectomy and adequate lymphadenectomy performed at high volume hospitals remain the backbone of GC treatment. Importantly, adequate GC surgery should be integrated in the setting of a multimodal treatment approach. Treatment for advanced GC continues to expand with the emergence of additional lines of systemic and targeted therapies.

Yttrium-90 Radioembolization in Patients with Hepatocellular Carcinoma Who have Previously Received Sorafenib

Purpose: Yttrium-90 radioembolization (RE) is a locoregional therapy option for hepatocellular carcinoma (HCC). Sorafenib is a multikinase inhibitor used in HCC that can potentially affect the efficacy of RE by altering tumor vascularity or suppressing post-irradiation angiogenesis. The safety and efficacy of sorafenib followed by RE has not been previously reported.

Materials and Methods: Patients with HCC who received RE after sorafenib were included in this retrospective review. Overall survival, toxicity, and maximal radiographic response and necrosis criteria were examined.

Results: Ten patients (15 RE administrations) fit the inclusion criteria. All were Barcelona Clinic Liver Cancer (BCLC) stage C. Median follow-up was 16.5 weeks. Median overall survival and radiographic progression-free survival were 30 and 28 weeks, respectively. Significant differences in overall survival were seen based on Child-Pugh class (p = 0.002) and radiographic response (p = 0.009). Three patients had partial response, six had stable disease, and one had progressive disease. Grade 1 or 2 acute fatigue, anorexia, and abdominal pain were common. Three patients had Grade 3 ascites in the setting of disease progression. Two patients had Grade 3 biochemical toxicity. One patient was sufficiently downstaged following RE and sorafenib to receive a partial hepatectomy.

Conclusion: Yttrium-90 RE in patients with HCC who have received sorafenib demonstrate acceptable toxicity and rates of radiographic response. However, the overall survival is lower than that reported in the literature on RE alone or sorafenib alone. This may be due in part to more patients in this study having advanced disease compared to these other study populations. Larger prospective studies are needed to determine whether the combination of RE and sorafenib is superior to either therapy alone.

Risk factors for posttreatment edema in patients treated with stereotactic radiosurgery for meningiomas

BACKGROUND

Peritumoral edema is a recognized complication following stereotactic radiosurgery (SRS).

OBJECTIVE

To evaluate the risk of posttreatment peritumoral edema following SRS for intracranial meningiomas and determine predictive factors.

METHODS

Between 2002 and 2008, 173 evaluable patients underwent CyberKnife or Gamma Knife SRS for meningiomas. Eighty-four patients (49%) had prior surgical resections, 13 patients had World Health Organization grade II (atypical) meningiomas, and 117 patients had a neurological deficit before SRS. Sixty-two tumors were in parasagittal, parafalcine, and convexity locations. The median tumor volume was 4.7 mL (range, 0.1-231.8 mL). The median prescribed dose and median prescribed biologically equivalent dose were 15 Gy (range, 9-40 Gy) and 67 Gy (range, 14-116 Gy), respectively. Ninety-seven patients were treated with single-fraction SRS, 74 received 2 to 5 fractions, and 2 received >5 fractions.

RESULTS

The median follow-up was 21.0 months. Thirteen patients (8%) developed symptomatic peritumoral edema, with a median onset time of 4.5 months (range, 0.2-9.5 months). The 3-, 6-, 12-, and 24-month actuarial symptomatic edema rates were 2.9%, 4.9%, 7.7%, and 8.5%, respectively. The crude tumor control rate was 94%. On univariate analysis, large tumor volume (P = .01) and single-fraction SRS (P = .04) were predictive for development of posttreatment edema.

CONCLUSION

SRS meningioma treatment demonstrated a low incidence of toxicity; however, large tumor volumes and single-fraction SRS treatment had an increased risk for posttreatment edema. Risk factors for edema should be considered in meningiomas treatment.

Preoperative chemoradiation for rectal cancer using capecitabine and celecoxib correlated with posttreatment assessment of thymidylate synthase and thymidine phosphorylase expression

PURPOSE

Thymidylate synthase (TS) and thymidine phosphorylase (TP) expression have been shown to be predictors of response to therapy. The toxicity, efficacy, surgical morbidity, and immunohistochemical TS and TP expression were assessed in surgical resection specimens after preoperative chemoradiation.

METHODS AND MATERIALS

Twenty patients with clinical stage I to III rectal adenocarcinoma received preoperative chemoradiation and underwent surgical resection 6 weeks later.

RESULTS

Posttreatment tumor stages were T1 to T2 and N0 in 30% of patients; T3 to T4 and N0 in 30% of patients; and T1 to T3 and N1 to N2 in 15% of patients. Pathologic complete response (pCR) was evident in 25% and tumor regression occurred in a total of 80% of patients. Anal sphincter-sparing surgery was performed in 80% of cases. Acute and perioperative complications were minimal, with no grade 3/4 toxicity or treatment breaks. Pelvic control was obtained in 90% of patients. With a median follow-up of 65.5 months (range, 8-80 months), the 6-year actuarial survival rate was 75%. Local failure was significantly associated with nonresponse to therapy and with high TS and low TP expression (p = 0.008 and p = 0.04, respectively).

CONCLUSIONS

The combination of capecitabine, celecoxib, and x-radiation therapy yields excellent response: a 25% pathologic pCR, no acute grade 3/4 toxicity, and minimal surgical morbidity. Nonresponders expressed significantly increased TS levels and decreased TP levels in posttreatment resection specimens compared to responders.