Definitive Proton Beam Therapy for Second Primary Non-small Cell Lung Cancer After Pneumonectomy Shows Promising Results

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Researchers from the University of Tsukuba investigated the outcome of definitive proton beam therapy (PBT) for second primary non-small cell lung cancer occurring in the contralateral lung after pneumonectomy. The study involved 4 patients with squamous cell carcinoma who underwent PBT between January 2006 and December 2019. The patients had a median age of 69 years and a median time from pneumonectomy to PBT initiation of 104.5 months. The results showed a median survival time of 46.6 months, with 3 patients dying of their primary disease and one dying of bacterial pneumonia.

Key Takeaways:

  • The study showed promising results for definitive PBT for second primary non-small cell lung cancer after pneumonectomy, with a median survival time of 46.6 months.
  • All patients who underwent PBT had a histology of squamous cell carcinoma and were inoperable due to poor respiratory function.
  • The treatment resulted in local recurrence inside the irradiated field, outside the irradiated field, and regional relapses, with a median time to relapse of 21.5 months.

*Grade 2 pneumonitis occurred in 2 patients, but steroid administration was not required; no grade 3 pneumonitis was observed.

  • The study's small sample size limits the generalizability of its findings, but the results suggest that definitive PBT may be a viable treatment option for patients with second primary non-small cell lung cancer after pneumonectomy.
  • The researchers recommend further studies to confirm the efficacy of PBT for this specific patient population.

Statistics:

  • 4 patients underwent PBT between January 2006 and December 2019.
  • The median age of the patients was 69 years.
  • The median time from pneumonectomy to PBT initiation was 104.5 months.
  • The median survival time was 46.6 months.
  • 3 patients died of their primary disease and one died of bacterial pneumonia.
  • 2 patients experienced grade 2 pneumonitis, but steroid administration was not required.
  • The median time to relapse was 21.5 months.

Sources:

  • NewsRx LLC. Data on Non-Small Cell Lung Cancer Reported by Researchers at University of Tsukuba (Definitive Proton Beam Therapy for Second Primary Non-small Cell Lung Cancer After Pneumonectomy). Cancer Weekly. October 21, 2025; p 350.
  • Definitive Proton Beam Therapy for Second Primary Non-small Cell Lung Cancer After Pneumonectomy. International Journal of Particle Therapy, 2025;18:101202.