title: Second cancer risk after chemotherapy for Hodgkin's lymphoma: a collaborative British cohort study.
abstract: OBJECTIVE
  We investigated the long-term risk of second primary malignancy after chemotherapy for Hodgkin's lymphoma (HL) in a much larger cohort than any yet published, to our knowledge.
  
  
  METHODS
  We followed 5,798 patients with HL treated with chemotherapy in Britain from 1963 to 2001--of whom 3,432 also received radiotherapy--to assess second primary malignancy risks compared with general population-based expectations.
  
  
  RESULTS
  Second malignancies occurred in 459 cohort members. Relative risk (RR) of second cancer was raised after chemotherapy alone (RR, 2.0; 95% CI, 1.7 to 2.4) but was much lower than after combined modalities (RR, 3.9; 95% CI, 3.5 to 4.4). After chemotherapy alone, there were significantly raised risks of lung cancer, non-HL, and leukemia, each contributing approximately equal absolute excess risk. After combined modalities, there were raised risks of these and several other cancers. Second cancer risk peaked 5 to 9 years after chemotherapy alone, but it remained raised for 25 years and longer after combined modalities. Risk was raised after each common chemotherapy regimen except, based on limited numbers and follow-up, adriamycin, bleomycin, vinblastine, and dacarbazine. The age and time-course relations of lung cancer differed between chemotherapy alone and combined modalities.
  
  
  CONCLUSIONS
  Although chemotherapy alone leads to raised risk of second malignancy, this risk is lower and affects fewer anatomic sites than that after combined modalities, and it is slight if at all after 15 years follow-up. The mechanism of lung cancer etiology may differ between chemotherapy and radiotherapy.
authors.affiliation: Section of Epidemiology, Sir Richard Doll Building, Institute of Cancer Research, Sutton, Surrey SM2 5NG, United Kingdom. anthony.swerdlow@icr.ac.uk
authors.forename: Anthony J
authors.initials: AJ
authors.lastname: Swerdlow
authors.forename: Craig D
authors.initials: CD
authors.lastname: Higgins
authors.forename: Paul
authors.initials: P
authors.lastname: Smith
authors.forename: David
authors.initials: D
authors.lastname: Cunningham
authors.forename: Barry W
authors.initials: BW
authors.lastname: Hancock
authors.forename: Alan
authors.initials: A
authors.lastname: Horwich
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Hoskin
authors.forename: T Andrew
authors.initials: TA
authors.lastname: Lister
authors.forename: John A
authors.initials: JA
authors.lastname: Radford
authors.forename: Ama Z S
authors.initials: AZ
authors.lastname: Rohatiner
authors.forename: David C
authors.initials: DC
authors.lastname: Linch
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D015331:Cohort Studies; D005260:Female; D005500:Follow-Up Studies; D006689:Hodgkin Disease / Q000188:drug therapy* / Q000532:radiotherapy*; D006801:Humans; D053208:Kaplan-Meier Estimate; D007938:Leukemia / Q000175:diagnosis / Q000453:epidemiology; D008175:Lung Neoplasms / Q000175:diagnosis / Q000453:epidemiology; D008228:Lymphoma, Non-Hodgkin / Q000175:diagnosis / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D016609:Neoplasms, Second Primary / Q000175:diagnosis* / Q000453:epidemiology*; D018714:Radiotherapy, Adjuvant; D018570:Risk Assessment; D012307:Risk Factors; D013997:Time Factors; D006113:United Kingdom / Q000453:epidemiology; D055815:Young Adult