Alliance for clinical trials in Oncology (Alliance) trial A022101/NRG-GI009: a pragmatic randomized phase III trial evaluating total ablative therapy for patients with limited metastatic colorectal cancer: evaluating radiation, ablation, and surgery (ERASur)

BACKGROUND

For patients with liver-confined metastatic colorectal cancer (mCRC), local therapy of isolated metastases has been associated with long-term progression-free and overall survival (OS). However, for patients with more advanced mCRC, including those with extrahepatic disease, the efficacy of local therapy is less clear although increasingly being used in clinical practice. Prospective studies to clarify the role of metastatic-directed therapies in patients with mCRC are needed.

METHODS

The Evaluating Radiation, Ablation, and Surgery (ERASur) A022101/NRG-GI009 trial is a randomized, National Cancer Institute-sponsored phase III study evaluating if the addition of metastatic-directed therapy to standard of care systemic therapy improves OS in patients with newly diagnosed limited mCRC. Eligible patients require a pathologic diagnosis of CRC, have BRAF wild-type and microsatellite stable disease, and have 4 or fewer sites of metastatic disease identified on baseline imaging. Liver-only metastatic disease is not permitted. All metastatic lesions must be amenable to total ablative therapy (TAT), which includes surgical resection, microwave ablation, and/or stereotactic ablative body radiotherapy (SABR) with SABR required for at least one lesion. Patients without overt disease progression after 16-26 weeks of first-line systemic therapy will be randomized 1:1 to continuation of systemic therapy with or without TAT. The trial activated through the Cancer Trials Support Unit on January 10, 2023. The primary endpoint is OS. Secondary endpoints include event-free survival, adverse events profile, and time to local recurrence with exploratory biomarker analyses. This study requires a total of 346 evaluable patients to provide 80% power with a one-sided alpha of 0.05 to detect an improvement in OS from a median of 26 months in the control arm to 37 months in the experimental arm with a hazard ratio of 0.7. The trial uses a group sequential design with two interim analyses for futility.

DISCUSSION

The ERASur trial employs a pragmatic interventional design to test the efficacy and safety of adding multimodality TAT to standard of care systemic therapy in patients with limited mCRC.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT05673148, registered December 21, 2022.

Alliance for Clinical Trials in Oncology (Alliance) trial A022101/NRG-GI009: A pragmatic randomized phase III trial evaluating total ablative therapy for patients with limited metastatic colorectal cancer: evaluating radiation, ablation, and surgery (ERASur)

Background

For patients with liver-confined metastatic colorectal cancer (mCRC), local therapy of isolated metastases has been associated with long-term progression-free and overall survival (OS). However, for patients with more advanced mCRC, including those with extrahepatic disease, the efficacy of local therapy is less clear although increasingly being used in clinical practice. Prospective studies to clarify the role of metastatic-directed therapies in patients with mCRC are needed.

Methods

The Evaluating Radiation, Ablation, and Surgery (ERASur) A022101/NRG-GI009 trial is a randomized, National Cancer Institute-sponsored phase III study evaluating if the addition of metastatic-directed therapy to standard of care systemic therapy improves OS in patients with newly diagnosed limited mCRC. Eligible patients require a pathologic diagnosis of CRC, have BRAF wild-type and microsatellite stable disease, and have 4 or fewer sites of metastatic disease identified on baseline imaging. Liver-only metastatic disease is not permitted. All metastatic lesions must be amenable to total ablative therapy (TAT), which includes surgical resection, microwave ablation, and/or stereotactic ablative body radiotherapy (SABR) with SABR required for at least one lesion. Patients without overt disease progression after 16-26 weeks of first-line systemic therapy will be randomized 1:1 to continuation of systemic therapy with or without TAT. The trial activated through the Cancer Trials Support Unit on January 10, 2023. The primary endpoint is OS. Secondary endpoints include event-free survival, adverse events profile, and time to local recurrence with exploratory biomarker analyses. This study requires a total of 346 evaluable patients to provide 80% power with a one-sided alpha of 0.05 to detect an improvement in OS from a median of 26 months in the control arm to 37 months in the experimental arm with a hazard ratio of 0.7. The trial uses a group sequential design with two interim analyses for futility.

Discussion

The ERASur trial employs a pragmatic interventional design to test the efficacy and safety of adding multimodality TAT to standard of care systemic therapy in patients with limited mCRC.

Alliance A022101: A Pragmatic Randomized Phase III Trial Evaluating Total Ablative Therapy for Patients with Limited Metastatic Colorectal Cancer - Evaluating Radiation, Ablation and Surgery (ERASur)

PURPOSE/OBJECTIVE(S)

For patients with oligometastatic colorectal cancer (CRC), aggressive local therapy of isolated metastases, particularly in the liver, has been associated with long-term progression-free survival and overall survival (OS) primarily based on retrospective evidence. However, in patients with limited metastatic CRC that is deemed inoperable or those with additional disease outside of the liver or lungs, the role of local ablative therapies, including microwave ablation (MWA) and stereotactic body radiation therapy (SBRT), to render patients disease free is less clear. Further, despite the long history of treating oligometastatic CRC with local therapy, which is provider biased and not evidence based, questions remain regarding the benefit of extending the paradigm of metastatic directed therapy to patients with more extensive disease. This trial seeks to use a pragmatic multimodality approach that mirrors the current clinical dilemma. This study is designed to evaluate the safety and efficacy of adding total ablative therapy (TAT) of all sites of disease to standard of care systemic treatment in those with limited metastatic CRC.

MATERIALS/METHODS

A022101 is a National Clinical Trials Network randomized phase III study planned to enroll 364 patients with newly diagnosed metastatic CRC (BRAF wild-type, microsatellite stable) with 4 or fewer sites of metastatic disease on baseline imaging. Liver-only metastatic disease is not permitted, and lesions must be amenable to any combination of surgical resection, MWA, and/or SBRT with SBRT required for at least one lesion. Patients receive first-line systemic therapy for 4-6 months and are then randomized 1:1, stratified by number of metastatic organ sites (1-2 vs. 3-4), timing of metastatic disease diagnosis (de novo vs. secondary), and presence of metastatic disease outside the liver and lungs in at least one site. Patients in Arm 1 will receive TAT which consists of treatment of all metastatic sites with SBRT ± MWA ± surgical resection followed by standard of care systemic therapy. Patients in Arm 2 will continue with standard of care systemic therapy alone. The primary endpoint is OS. Secondary endpoints include event-free survival, treatment-related toxicities, and local recurrence with exploratory biomarker analyses. The study needs 346 evaluable patients combined in the 2 arms to demonstrate an improvement in OS with a hazard ratio of 0.7 to provide 80% power with a one-sided alpha of 5%. The trial utilizes a group sequential design with two interim analyses (25% and 50% of events) for futility.

RESULTS

The trial activated in January 2023.

CONCLUSION

Recruitment is ongoing.

Reducing seed migration to near zero with stranded-seed implants: Comparison of seed migration rates to the chest in 1000 permanent prostate brachytherapy patients undergoing implants with loose or stranded seeds

PURPOSE

Pulmonary seed emboli to the chest may occur after permanent prostate brachytherapy (PPB). The purpose of this study is to analyze factors associated with seed migration to the chest in a large series of PPB patients from a single institution undergoing implant with either loose seeds (LS), mixed loose and stranded seeds (MS), or exclusively stranded seeds in an absorbable vicryl suture (VS).

METHODS AND MATERIALS

Between May 1998 and July 2015, a total of 1000 consecutive PPB patients with postoperative diagnostic chest x-rays at 4 months after implant were analyzed for seed migration. Patients were grouped based on seed implant technique: LS = 391 (39.1%), MS = 43 (4.3%), or VS = 566 (56.6%). Univariate and multivariate analysis were performed using Cox proportional hazards regression models to determine predictors of seed migration.

RESULTS

Overall, 18.8% of patients experienced seed migration to the chest. The incidence of seed migration per patient was 45.5%, 11.6%, and 0.9% (p < 0.0001), for patients receiving LS, MS, or VS PPB, respectively. The right and left lower lobes were the most frequent sites of pulmonary seed migration. On multivariable analysis, planimetry volume (p = 0.0002; HR = 0.7 per 10 cc [0.6-0.8]), number of seeds implanted (p < 0.0001, HR = 2.4 per 25 seeds [1.7-3.4]), LS implant (p < 0.0001, HR = 15.9 [5.9-42.1]), and MS implant (p = 0.001, HR = 7.9 [2.3-28.1]) were associated with seed migration to the chest.

CONCLUSIONS

In this large series, significantly higher rates of seed migration to the chest are observed in implants using any LS with observed hazard ratios of 15.9 and 7.9 for LS and MS respectively, as compared with implants using solely stranded seeds.

Inhibition of the epithelial Na+ channel by interaction of Nedd4 with a PY motif deleted in Liddle's syndrome

The epithelial Na+ channel (ENaC) plays a critical role in Na+ absorption in the kidney and other epithelia. Mutations in the C terminus of the beta or gammaENaC subunits increase renal Na+ absorption, causing Liddle's syndrome, an inherited form of hypertension. These mutations delete or disrupt a PY motif that was recently shown to interact with Nedd4, a ubiquitin-protein ligase expressed in epithelia. We found that Nedd4 inhibited ENaC when they were coexpressed in Xenopus oocytes. Liddle's syndrome-associated mutations that prevent the interaction between Nedd4 and ENaC abolished inhibition, suggesting that a direct interaction is required for inhibition by Nedd4. Inhibition also required activity of a ubiquitin ligase domain within the C terminus of Nedd4. Nedd4 had no detectable effect on the single channel properties of ENaC. Rather, Nedd4 decreased cell surface expression of both ENaC and a chimeric protein containing the C terminus of the beta subunit. Decreased surface expression resulted from an increase in the rate of degradation of the channel complex. Thus, interaction of Nedd4 with the C terminus of ENaC inhibits Na+ absorption, and loss of this interaction may play a role in the pathogenesis of Liddle's syndrome and other forms of hypertension.