Adjuvant Radiation Therapy Treatment Time Impacts Overall Survival in Gastric Cancer

Journal Article · Thu Oct 01 04:00:00 EDT 2015 · International Journal of Radiation Oncology, Biology and Physics

DOI:https://doi.org/10.1016/J.IJROBP.2015.05.025· OSTI ID:22458779

McMillan, Matthew T. ^[1]; Ojerholm, Eric ^[1]; Plastaras, John P.; Metz, James M. ^[1]; Mamtani, Ronac ^[2]; Karakousis, Giorgos C.; Fraker, Douglas L.; Drebin, Jeffrey A. ^[3]; Stripp, Diana; Ben-Josef, Edgar ^[1]; Datta, Jashodeep ^[3]

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1. Department of Radiation Oncology, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania (United States)
2. Department of Hematology/Oncology, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania (United States)
3. Department of Surgery, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania (United States)

Purpose: Prolonged radiation therapy treatment time (RTT) is associated with worse survival in several tumor types. This study investigated whether delays during adjuvant radiation therapy impact overall survival (OS) in gastric cancer. Methods and Materials: The National Cancer Data Base was queried for patients with resected gastric cancer who received adjuvant radiation therapy with National Comprehensive Cancer Network–recommended doses (45 or 50.4 Gy) between 1998 and 2006. RTT was classified as standard (45 Gy: 33-36 days, 50.4 Gy: 38-41 days) or prolonged (45 Gy: >36 days, 50.4 Gy: >41 days). Cox proportional hazards models evaluated the association between the following factors and OS: RTT, interval from surgery to radiation therapy initiation, interval from surgery to radiation therapy completion, radiation therapy dose, demographic/pathologic and operative factors, and other elements of adjuvant multimodality therapy. Results: Of 1591 patients, RTT was delayed in 732 (46%). Factors associated with prolonged RTT were non-private health insurance (OR 1.3, P=.005) and treatment at non-academic facilities (OR 1.2, P=.045). Median OS and 5-year actuarial survival were significantly worse in patients with prolonged RTT compared with standard RTT (36 vs 51 months, P=.001; 39 vs 47%, P=.005); OS worsened with each cumulative week of delay (P<.0004). On multivariable analysis, prolonged RTT was associated with inferior OS (hazard ratio 1.2, P=.002); the intervals from surgery to radiation therapy initiation or completion were not. Prolonged RTT was particularly detrimental in patients with node positivity, inadequate nodal staging (<15 nodes examined), and those undergoing a cycle of chemotherapy before chemoradiation therapy. Conclusions: Delays during adjuvant radiation therapy appear to negatively impact survival in gastric cancer. Efforts to minimize cumulative interruptions to <7 days should be considered.

• OSTI ID: 22458779
• Journal Information: International Journal of Radiation Oncology, Biology and Physics, Journal Name: International Journal of Radiation Oncology, Biology and Physics Journal Issue: 2 Vol. 93; ISSN IOBPD3; ISSN 0360-3016
• Country of Publication: United States
• Language: English

Related Subjects

62 RADIOLOGY AND NUCLEAR MEDICINE
CHEMOTHERAPY
COMPARATIVE EVALUATIONS
HAZARDS
INSURANCE
NEOPLASMS
PATIENTS
RADIATION DOSES
RADIOTHERAPY
SURGERY