title: Radiation-related risk of basal cell carcinoma: a report from the Childhood Cancer Survivor Study.
abstract: BACKGROUND
  Basal cell carcinoma (BCC) is the most common malignancy in the United States. Ionizing radiation is an established risk factor in certain populations, including cancer survivors. We quantified the association between ionizing radiation dose and the risk of BCC in childhood cancer survivors.
  
  
  METHODS
  Participants in the Childhood Cancer Survivor Study who reported a BCC (case subjects, n = 199) were matched on age and length of follow-up to three study participants who had not developed a BCC (control subjects, n = 597). The radiation-absorbed dose (in Gy) to the BCC location was calculated based on individual radiotherapy records using a custom-designed dosimetry program. Conditional logistic regression was used to calculate odds ratios (ORs) and 95% confidence intervals (CIs) for associations between demographic and treatment factors, therapeutic radiation dose, and surrogate markers of sun sensitivity (skin and hair color) and the risk of BCC. A linear dose-response model was fitted to evaluate the excess odds ratio per Gy of radiation dose.
  
  
  RESULTS
  Among case subjects, 83% developed BCC between the ages of 20 and 39 years. Radiation therapy, either alone or in combination with chemotherapy, was associated with an increased risk of BCC compared with no chemotherapy or radiation. The odds ratio for subjects who received 35 Gy or more to the skin site vs no radiation therapy was 39.8 (95% CI = 8.6 to 185). Results were consistent with a linear dose-response relationship, with an excess odds ratio per Gy of 1.09 (95% CI = 0.49 to 2.64). No other treatment variables were statistically significantly associated with an increased risk of BCC.
  
  
  CONCLUSIONS
  Radiation doses to the skin of more than 1 Gy are associated with an increased risk of BCC.
authors: Department of Pediatric Oncology, UT Southwestern Medical Center, Dallas, TX, USA.
authors: Tanya C
authors: TC
authors: Watt
authors: Peter D
authors: PD
authors: Inskip
authors: Kayla
authors: K
authors: Stratton
authors: Susan A
authors: SA
authors: Smith
authors: Stephen F
authors: SF
authors: Kry
authors: Alice J
authors: AJ
authors: Sigurdson
authors: Marilyn
authors: M
authors: Stovall
authors: Wendy
authors: W
authors: Leisenring
authors: Leslie L
authors: LL
authors: Robison
authors: Ann C
authors: AC
authors: Mertens
mesh_terms: D000293:Adolescent; D002280:Basal Cell Carcinoma / Q000453:epidemiology* / Q000209:etiology*; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D004307:Dose-Response Relationship, Radiation; D005260:Female; D006200:Hair Color; D006801:Humans; D016014:Linear Models; D016015:Logistic Models; D008297:Male; D009381:Neoplasms, Radiation-Induced / Q000453:epidemiology* / Q000209:etiology*; D016017:Odds Ratio; D011839:Radiation, Ionizing; D011879:Radiotherapy Dosage; D012189:Retrospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D012867:Skin / Q000528:radiation effects; D012878:Skin Neoplasms / Q000453:epidemiology* / Q000209:etiology*; D012880:Skin Pigmentation; D013472:Sunlight / Q000009:adverse effects*; D017741:Survivors / Q000706:statistics & numerical data; D014481:United States / Q000453:epidemiology