title: The cigarette burden (measured by the number of pack-years smoked) negatively impacts the response rate to platinum-based chemotherapy in lung cancer patients.
abstract: OBJECTIVE
  To evaluate the impact of the cigarette burden (CB) on the response rate to platinum-based chemotherapy (CT) in patients with lung cancer (LC).
  
  
  METHODS
  Retrospective study of patients with LC treated by CT from 2000 to 2005, in a tertiary referral center in Brazil. The CB was measured by the number of pack-years smoked (PY). To evaluate the response (by RECIST), it was necessary to accomplish two cycles of CT. The relevant variables were studied by univariate and multivariate statistical techniques.
  
  
  RESULTS
  Two hundred and eighty-five patients (203 men) were studied (mean age=60.6+/-10.1 years, mean PY=58.3+/-35.4). 62.8% were current smokers, 26.7% were former smokers, and 10.5% were non-smokers. 63.2% had non-small-cell lung cancer (NSCLC), and 36.8% had small-cell lung cancer (SCLC). The treatment intent was palliative in 63.9% and curative in 36.1%. All 285 patients received platinum-based CT (etoposide/cisplatin in 68.8% and etoposide/carboplatin in 31.2%). Of these, 155 patients (54.4%) received RT (median dose=50.0 Gy; range=45.0-80.0). The 94 patients (33.0%) who responded to treatment had a mean PY of 38.7+/-27.1, and the 191 patients (67.0%) who did not respond had a mean PY of 67.8+/-35.1, p<0.001. In the multivariate analysis, the main independent negative predictor was CB>or=40 PY (adjusted OR=10.42; 95% CI=5.13-21.28). The others independent negative predictors were: CT (no. of cycles=2-4) (adjusted OR=4.86; 95% CI=2.44-9.68), treatment regimen with CT alone (adjusted OR=3.38; 95% CI=1.67-6.84), and NSCLC histology (adjusted OR=2.75; 95% CI=1.12-6.76).
  
  
  CONCLUSIONS
  Patients with CB>or=40 PY have a worse response to platinum-based CT compared to those who have a CB<40 PY.
authors.affiliation: Instituto de Doenças do Tórax-Hospital Universitário Clementino Fraga Filho, Rio de Janeiro, Brazil. rlmduarte@gmail.com
authors.forename: Ricardo L M
authors.initials: RL
authors.lastname: Duarte
authors.forename: Ronir R
authors.initials: RR
authors.lastname: Luiz
authors.forename: Marcos E M
authors.initials: ME
authors.lastname: Paschoal
mesh_terms: D000368:Aged; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D001938:Brazil; D002289:Carcinoma, Non-Small-Cell Lung / Q000175:diagnosis / Q000188:drug therapy* / Q000473:pathology / Q000503:physiopathology; D018288:Carcinoma, Small Cell / Q000175:diagnosis / Q000188:drug therapy* / Q000473:pathology / Q000503:physiopathology; D006801:Humans; D008175:Lung Neoplasms / Q000175:diagnosis / Q000188:drug therapy* / Q000473:pathology / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D010984:Platinum / Q000008:administration & dosage*; D011379:Prognosis; D012189:Retrospective Studies; D012307:Risk Factors; D012907:Smoking / Q000009:adverse effects*; D016896:Treatment Outcome
chemical_list: D010984:Platinum