title: Tumour size reduction after the first chemotherapy-course and outcomes of chemoradiotherapy in limited disease small-cell lung cancer.
abstract: Concurrent chemotherapy and thoracic radiotherapy (TRT) is recommended for limited disease small-cell lung cancer (LD SCLC). TRT should start as early as possible, often meaning with the second course due to patient referral time and the fact that TRT planning takes time. Early assessment of response to the first course of chemotherapy may be a useful way to individualise treatment. The aims of this study were to assess tumour size reduction after the first chemotherapy-course, and whether this reduction was associated with outcomes in LD SCLC.
  
  
  
  A randomised trial comparing twice-daily (45Gy/30 fractions) with once-daily (42Gy/15 fractions) TRT, given concurrently with four courses of cisplatin/etoposide (n=157) was the basis for this study. Tumour size was assessed on CT scans at baseline and planning scans for TRT according to RECIST 1.0.
  
  
  
  CT scans were available for 135 patients (86%). Ninety-four percent had a reduction in tumour size after the first chemotherapy-course. The median reduction in sum of diameters (SOD) of measurable lesions was ÷16mm (÷84 to +10mm), corresponding to ÷18% (÷51 to +12%). Eighty-two percent had stable disease, 18% partial response. Reduction in SOD was significantly associated with complete response at first follow-up (OR: 1.05, 95% CI 1.01-1.09; p=0.013), PFS (HR: 0.97, 95% CI 0.96-0.99; p=0.001), and overall survival (HR: 0.98, 95% CI 0.96-1.00; p=0.010).
  
  
  
  Response from the first course of chemotherapy had a significant positive association with outcomes from chemoradiotherapy, and might be used to stratify and randomise patients in future studies.
authors.affiliation: Department of Cancer Research and Molecular Medicine, NTNU, Norwegian University of Science and Technology, Trondheim, Norway; The Cancer Clinic, St. Olavs Hospital-Trondheim University Hospital, Trondheim, Norway. Electronic address: tarje.halvorsen@gmail.com.
authors.forename: Tarje Onsøien
authors.initials: TO
authors.lastname: Halvorsen
authors.affiliation: Clinic of Radiology and Nuclear Medicine, St. Olavs Hospital-Trondheim University Hospital, Trondheim, Norway.
authors.forename: Martin
authors.initials: M
authors.lastname: Herje
authors.affiliation: The Cancer Clinic, St. Olavs Hospital-Trondheim University Hospital, Trondheim, Norway.
authors.forename: Nina
authors.initials: N
authors.lastname: Levin
authors.affiliation: Department of Clinical Medicine, Faculty of Medicine, The Arctic University of Norway, Tromsø, Norway; Department of Oncology, University Hospital of North Norway, Tromsø, Norway.
authors.forename: Roy M
authors.initials: RM
authors.lastname: Bremnes
authors.affiliation: Department of Oncology, Oslo University Hospital, The Norwegian Radium Hospital, Oslo, Norway; Institute of Clinical Medicine, University of Oslo, Oslo, Norway.
authors.forename: Odd T
authors.initials: OT
authors.lastname: Brustugun
authors.affiliation: Department of Thoracic Medicine, Haukeland University Hospital, Bergen, Norway.
authors.forename: Øystein
authors.initials: Ø
authors.lastname: Fløtten
authors.affiliation: Department of Cancer Research and Molecular Medicine, NTNU, Norwegian University of Science and Technology, Trondheim, Norway; The Cancer Clinic, St. Olavs Hospital-Trondheim University Hospital, Trondheim, Norway; Department of Oncology, Oslo University Hospital, The Norwegian Radium Hospital, Oslo, Norway; Institute of Clinical Medicine, University of Oslo, Oslo, Norway.
authors.forename: Stein
authors.initials: S
authors.lastname: Kaasa
authors.affiliation: The Cancer Clinic, St. Olavs Hospital-Trondheim University Hospital, Trondheim, Norway.
authors.forename: Stein
authors.initials: S
authors.lastname: Sundstrøm
authors.affiliation: Department of Cancer Research and Molecular Medicine, NTNU, Norwegian University of Science and Technology, Trondheim, Norway; The Cancer Clinic, St. Olavs Hospital-Trondheim University Hospital, Trondheim, Norway.
authors.forename: Bjørn H
authors.initials: BH
authors.lastname: Grønberg
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D059248:Chemoradiotherapy / Q000379:methods*; D003131:Combined Modality Therapy; D018572:Disease-Free Survival; D004358:Drug Therapy / Q000592:standards*; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000473:pathology / Q000628:therapy; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D009664:Norway / Q000453:epidemiology; D011879:Radiotherapy Dosage; D016032:Randomized Controlled Trials as Topic; D012074:Remission Induction; D055752:Small Cell Lung Carcinoma / Q000000981:diagnostic imaging / Q000188:drug therapy* / Q000473:pathology / Q000532:radiotherapy*; D016019:Survival Analysis; D063189:Symptom Assessment / Q000379:methods*; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome; D047368:Tumor Burden / Q000187:drug effects*
keywords: Chemotherapy; Concurrent; Early response; Predictive; Radiotherapy; Survival