Impact of unfavorable factors on outcomes among inoperable stage II-IV Nonsmall cell lung cancer patients treated with proton therapy

Acta Oncol. 2019 Mar;58(3):313-319. doi: 10.1080/0284186X.2018.1546060. Epub 2019 Jan 18.


Purpose: To investigate the impact of unfavorable risk factors among patients with locally advanced nonsmall cell lung cancer (LA-NSCLC) treated with proton therapy (PT).

Material and methods: From May 2008 through July 2015, 90 consecutive patients with unresectable stage II-IV (oligometastatic) NSCLC were treated with PT. Unfavorable factors including age ≥80 years, stage IV, weight loss >10% in 3 months, performance status (PS) ≥2, FEV1 < 1.0 or O2 dependency, prior lung cancer, prior lung surgery, prior 2nd cancer in the past 3 years, and prior chest irradiation were evaluated. All patients received standard fractionation of 1.8-2 Gy(RBE) (median dose, 70 Gy[RBE]). Overall survival (OS) and progression-free survival (PFS) were calculated with the Kaplan-Meier method. The impact of unfavorable factors was analyzed in Cox regression models.

Results: Twenty-six percent were favorable-risk, while 42%, 22%, and 10% had 1-, 2-, or ≥3 unfavorable factors. The 2-year OS was 52% and 45% (p = .8522), and 2-year PFS was 21% and 44% (p = .0207), for favorable and unfavorable risk patients, respectively. Among patients with stage III-IV, only PS ≥2 adversely impacted OS (p = .0015).

Conclusion: Most patients treated with PT for LA-NSCLC have unfavorable risk factors. These patients had similar outcomes to favorable-risk patients. Enrollment in future clinical trials may improve if eligibility is less restrictive.

Publication types

  • Clinical Trial

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Antineoplastic Agents / adverse effects
  • Antineoplastic Agents / therapeutic use
  • Carcinoma, Non-Small-Cell Lung / drug therapy
  • Carcinoma, Non-Small-Cell Lung / mortality
  • Carcinoma, Non-Small-Cell Lung / radiotherapy*
  • Carcinoma, Non-Small-Cell Lung / surgery
  • Disease-Free Survival
  • Dose Fractionation, Radiation
  • Female
  • Humans
  • Kaplan-Meier Estimate
  • Lung Neoplasms / drug therapy
  • Lung Neoplasms / mortality
  • Lung Neoplasms / radiotherapy*
  • Lung Neoplasms / surgery
  • Male
  • Middle Aged
  • Proton Therapy / adverse effects
  • Proton Therapy / methods*
  • Retrospective Studies
  • Treatment Outcome


  • Antineoplastic Agents