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A Win for Adjuvant Immunotherapy in Esophageal Cancer

— And other highlights from the Society of Surgical Oncology's virtual 2021 meeting

MedpageToday
Three surgeons performing a surgery

Patients with resected esophageal or gastroesophageal junction (GEJ) cancer lived significantly longer without disease recurrence when they received the checkpoint inhibitor nivolumab (Opdivo) after surgery, a large randomized trial showed.

Median disease-free survival (DFS) doubled from 11.0 months with no adjuvant therapy to 22.4 months with a year of adjuvant nivolumab. The difference translated into a 31% reduction in the hazard for disease recurrence or death in favor of nivolumab (96.4% CI 0.56-0.86, P=0.0003). The majority of treatment-related adverse events (TRAEs) were grade 1/2, and fewer than 10% of patients in the nivolumab arm had serious TRAEs or discontinued treatment because of AEs.

The findings are the first to show clinically significant improvement in DFS with adjuvant therapy for resectable gastric/GEJ cancer.

"These breakthrough results represent the first treatment advance in many years for patients with operable esophageal and gastroesophageal junction cancer, potentially establishing adjuvant nivolumab as a new standard of care for these difficult-to-treat tumors," reported Guillaume Piessen, MD, PhD, of Claude Huriez University Hospital and the University of Lille in France, during the virtual meeting.

The findings came from the CheckMate 577 trial involving 794 patients with operable stage II/III esophageal or GEJ cancer. All patients received standard neoadjuvant chemoradiation and surgery, and those with residual disease were randomized 2:1 to adjuvant nivolumab or placebo. The primary endpoint was DFS.

Despite widespread use of trimodality therapy (chemotherapy, radiotherapy, and surgery), disease recurrence remains a major challenge for patients with stage II/III esophageal or GEJ cancer, particularly the 75% of patients who do not achieve pathologic complete response with neoadjuvant therapy, Piessen noted. Currently, no standard of care exists for the setting, providing a rationale to evaluate adjuvant immunotherapy with nivolumab.

Adjuvant Immunotherapy Boosts OS in Melanoma

Three-year overall survival (OS) improved significantly in patients with stage IIb/c melanoma treated with immunotherapy after surgery, a retrospective review of 10,592 cases showed.

Among patients who received adjuvant immunotherapy, the 3-year OS was 82.7% as compared with 71.6% for patients who did not receive immunotherapy after surgery. The difference represented a 34% reduction in the survival hazard in favor of the adjuvant treatment (P<0.002). Separate analyses showed that adjuvant immunotherapy was associated with significantly better 3-year OS for stage IIb (86% vs 77%, P=0.0012) and IIc melanoma (79% vs 61%, P<0.0001), reported William G. Wong, DO, of Penn State Health Milton S. Hershey Medical Center in Hershey, Pennsylvania.

The retrospective analysis included patients treated for stage IIb/c melanoma during 2013 and 2017 and included in the . The study population included 419 (4.0%) patients who received adjuvant immunotherapy. Examination of utilization patterns showed that younger patients, women, patients living closer to a hospital, those with pathologic T4b, and those with positive surgical margins were more likely to receive adjuvant immunotherapy. A proportional hazards analysis confirmed a significant association between immunotherapy and 3-year OS.

The study is the first to demonstrate a significant survival advantage with adjuvant treatment of stage IIb/c melanoma, said Wong. More definitive data should come from the ongoing placebo-controlled trial evaluating adjuvant pembrolizumab (Keytruda) for high-risk stage II melanoma. In the meantime, adjuvant immunotherapy warrants consideration in appropriately selected patients with resected melanoma.

Sarculator: Promise for Estimating Sarcoma Survival

An online nomogram performed well in a test to predict survival after surgery for sarcomas of the extremities and trunk, according to a review of 9,738 patients.

Known as the , the four-item nomogram predicted a 5-year OS of 73.7% as compared with an actual OS of 68.9%, resulting in a C (concordance) index of 0.726. A comparison of outcomes by disease stage and tumor histology yielded values of 0.656 to 0.745.

A C index if 0.7 indicates a good prognostic model; 0.8 is a strong model, and 1.0 represents perfect concordance between a model and actual outcomes, said Rachel K. Voss, MD, of the MD Anderson Cancer Center in Houston.

"Overall, Sarculator is a good predictor of actual overall survival for U.S. primary extremity and trunk sarcoma patients," she said in a statement. "Sarculator performs slightly better for early stages and best for leiomyosarcoma, myxoid liposarcoma, and other histologies, and it is a good clinical tool for surgeons and oncologists to help with survival prognostication."

The Sarculator produces survival estimates on the basis of four factors: patient age and tumor size, grade, and histology. Developed in Europe, the nomogram's performance characteristics for U.S. patient populations had not been extensively investigated.

Using data from the National Cancer Database, Voss and colleagues evaluated the performance characteristics of the nomogram for patients with stage I-III primary extremity or trunk sarcoma treated during 2006-2016 and had R0/1 margin status after surgery.

Analysis by stage yielded C index values of 0.730 for stage I, 0.708 for stage II, and 0.679 for stage III sarcomas. Analysis by histology resulted in C index values of 0.745 for leiomyosarcoma, 0.719 for myxoid liposarcoma, 0.656 for peripheral nerve sheath tumor, 0.679 for liposarcoma, 0.694 for synovial sarcoma, and 0.719 for other histologies.

  • author['full_name']

    Charles Bankhead is senior editor for oncology and also covers urology, dermatology, and ophthalmology. He joined ֱ in 2007.

Disclosures

The CheckMate 577 trial was supported by Bristol Myers Squibb (BMS).

Piessen disclosed relevant relationships with BMS, Medtronic, Nestle, Roche, and Stryker.

Wong disclosed no relevant relationships with industry.

Primary Source

Society of Surgical Oncology

Kelly RJ, et al "Adjuvant nivolumab in resected esophageal or gastroesophageal junction cancer following neoadjuvant chemoradiation therapy: First results of the CheckMate 577 study" SSO 2021; Abstract 94.

Secondary Source

Society of Surgical Oncology

Wong WG, et al "Utilization and survival benefit of adjuvant immunotherapy in resected high-risk stage II melanoma: A National Cancer Database analysis" SSO 2021; Abstract 58.

Additional Source

Society for Surgical Oncology

Voss RK, et al "Sarculator is a good model to predict survival in resected, primary U.S. extremity and trunk sarcoma patients" SSO 2021; Abstract 84.