title: Is the time interval between surgery and radiotherapy important in operable nonsmall cell lung cancer? A retrospective analysis of 340 cases.
abstract: OBJECTIVE
  To evaluate the influence of prognostic factors in postoperative radiotherapy of NSCLC with special emphasis on the time interval between surgery and start of radiotherapy.
  
  
  METHODS
  Between January 1976 and December 1993, 340 cases were treated and retrospectively analyzed meeting the following criteria: complete follow-up; complete staging information including pathological confirmation of resection status; maximum interval between surgery (SX) and radiotherapy (RT) of 12 weeks (median 36 days, range 18 to 84 days); minimum dose of 50 Gy (R0), and maximum dose of 70 Gy (R2). Two hundred thirty patients (68%) had N2 disease; 228 patients were completely resected (R0). One hundred six (31%) had adenocarcinoma, 172 (51%) squamous cell carcinoma.
  
  
  RESULTS
  In univariate analysis, Karnofsky performance status (90+ >60-80%; p = 0.019 log rank), resection status stratified for nodal disease (R+ <R0; p = 0.046), and the time interval between SX and RT were of significant importance. Patients with a long interval (37 to 84 days) had higher 5-year survival rates (26%) and a median survival time (MST: 21.9 months, 95% C.I. 17.2 to 28.6 months) than patients with a short interval (18 to 36 days: 15%; 14.9 months, 13 to 19.9 months; p = 0.013). A further subgroup analysis revealed significant higher survival rates in patients with a long interval in N0/1 disease (p = 0.011) and incompletely resected NSCLC (p = 0.012). In multivariate analysis, the time interval had a p-value of 0.009 (nodal disease: p = 0.0083; KPI: p = 0.0037; sex: p = 0.035).
  
  
  CONCLUSIONS
  Shortening the time interval between surgery and postoperative radiotherapy to less than 6 weeks even in R+ cases is not necessary. Survival of patients with a long interval between surgery and start of radiotherapy was better in this retrospective analysis as compared to patients with a short interval.
authors.affiliation: Hermann-Holthusen-Institut für Strahlentherapie, AK St. Georg, Hamburg, Germany.
authors.forename: F
authors.initials: F
authors.lastname: Würschmidt
authors.forename: H
authors.initials: H
authors.lastname: Bünemann
authors.forename: M
authors.initials: M
authors.lastname: Ehnert
authors.forename: H P
authors.initials: HP
authors.lastname: Heilmann
mesh_terms: D000328:Adult; D000368:Aged; D002289:Carcinoma, Non-Small-Cell Lung / Q000473:pathology / Q000532:radiotherapy* / Q000601:surgery*; D002455:Cell Division; D003131:Combined Modality Therapy; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000473:pathology / Q000532:radiotherapy* / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D016017:Odds Ratio; D011379:Prognosis; D011658:Pulmonary Fibrosis / Q000209:etiology; D017564:Radiation Pneumonitis / Q000209:etiology; D011879:Radiotherapy Dosage; D012189:Retrospective Studies; D012737:Sex Factors; D015996:Survival Rate; D013997:Time Factors