ASCO-GI 2020 – Esophageal cancer: no survival benefit from boosted radiotherapy dose


  • Pavankumar Kamat
  • Univadis
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Takeaway

  • Boosting the standard dose of radiation therapy did not improve survival outcomes significantly for patients with esophageal cancer receiving definitive chemoradiation. 

Why this matters

  • The current standard dose of around 50 Gy for local-regional control in esophageal cancer is relatively lower than the dose used for malignancies of the larynx, lung, bladder, and cervix. 
  • A previous dose-escalation trial comparing high-dose with standard-dose was prematurely terminated and the negative findings from the trial were never clearly understood. 

Study design

  • Patients with stage T2-4, N0-3, M0 carcinoma of the esophagus and not suitable for surgery (n=260) were randomly assigned to receive either a standard dose of 50.4 Gy or a high dose of 61.6 Gy.
  • The chemotherapy regimen for both arms was six concurrent cycles of carboplatin and paclitaxel.
  • The primary endpoint was local progression-free survival (PFS). Secondary endpoints included locoregional PFS, overall survival (OS), and toxicity.
  • Funding: Dutch Cancer foundation KWF.

Key results

  • The 3-year local PFS was 71% in the standard-dose group vs 73% in the high-dose group.
  • The 3-year locoregional PFS was 53% in the standard-dose group vs 63% in the high-dose group.
  • The 3-year OS in the standard-dose group and the high-dose group was 41% and 40%, respectively.
  • The overall grade 4 and 5 toxicity was greater in the high-dose group vs the standard-dose group (grade 4: 13.6% vs 10.8%; grade 5: 8.5% vs 5%).

Limitations

  • Lower compliance rate in the high-dose group.

Expert commentary

Dr Sara Lonardi, MD, from the Institute of Oncology Veneto, Italy, said: "From a theoretical perspective, a boost should work and we should have seen positive results. This study used more modern radiation treatments and modern regimens of chemotherapy."