title: Ethnic difference in risk of toxicity in prostate cancer patients treated with dynamic arc radiation therapy.
abstract: OBJECTIVE
  The objective of this study was to assess the influence of ethnicity on toxicity in patients treated with dynamic arc radiation therapy (ART) for prostate cancer (PC).
  
  
  METHODS
  From June 2006 to May 2012, 162 cT1-T3 cN0 cM0 PC patients were treated with ART (primary diagnosis, n = 125; post-prostatectomy/brachytherapy biochemical recurrence, n = 26; adjuvant post-prostatectomy, n = 11) at 2 institutions. Forty-five patients were Latin Americans and 117 were Europeans. The dose prescribed to the prostate ranged between 68 Gy and 81 Gy.
  
  
  RESULTS
  The median age was 69 years (range 43-87 years). The median follow-up was 18 months (range 2-74 months). Overall, only 3 patients died, none due to a cancer-related cause. Biochemical recurrence was seen in 7 patients. The rates of acute grade 2 gastrointestinal (GI) and genitourinary (GU) toxicities were 19.7% and 17%, respectively. Only 1 patient experienced acute grade 3 GI toxicity, whereas 11 patients (6.7%) experienced acute grade 3 GU toxicity. Multivariate analysis showed that undergoing whole pelvic lymph node irradiation was associated with a higher grade of acute GI toxicity (OR: 3.46; p = 0.003). In addition, older age was marginally associated with a higher grade of acute GI toxicity (OR: 2.10; p = 0.074). Finally, ethnicity was associated with acute GU toxicity: Europeans had lower-grade toxicity (OR: 0.27; p = 0.001).
  
  
  CONCLUSIONS
  Our findings suggest an ethnic difference in GU toxicity for PC patients treated with ART. In addition, we found that ART is associated with a very low risk of severe toxicity and a low recurrence rate.
authors.affiliation: Master in Advanced Technological Applications in Radiation Oncology, University of Murcia and Grupo IMO Foundation, Madrid - Spain.
authors.forename: Jose L
authors.initials: JL
authors.lastname: Lopez Guerra
authors.forename: Raul
authors.initials: R
authors.lastname: Matute
authors.forename: Fernando
authors.initials: F
authors.lastname: Puebla
authors.forename: Alberto
authors.initials: A
authors.lastname: Sánchez-Reyes
authors.forename: Beatriz
authors.initials: B
authors.lastname: Pontes
authors.forename: Cristina
authors.initials: C
authors.lastname: Rubio
authors.forename: Isabel
authors.initials: I
authors.lastname: Nepomuceno
authors.forename: Catalina
authors.initials: C
authors.lastname: Acevedo
authors.forename: Nicolas
authors.initials: N
authors.lastname: Isa
authors.forename: Rafael
authors.initials: R
authors.lastname: Lengua
authors.forename: Juan Manuel
authors.initials: JM
authors.lastname: Praena-Fernandez
authors.forename: Eleonor Rivin
authors.initials: ER
authors.lastname: del Campo
authors.forename: Maria Jose
authors.initials: MJ
authors.lastname: Ortiz
authors.forename: Ignacio
authors.initials: I
authors.lastname: Azinovic
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000097:blood; D001918:Brachytherapy / Q000009:adverse effects*; D005500:Follow-Up Studies; D041981:Gastrointestinal Tract / Q000528:radiation effects*; D006630:Hispanic or Latino / Q000706:statistics & numerical data*; D006801:Humans; D008198:Lymph Nodes / Q000528:radiation effects; D008207:Lymphatic Metastasis / Q000532:radiotherapy; D008297:Male; D008875:Middle Aged; D060787:Neoplasm Grading; D016017:Odds Ratio; D017430:Prostate-Specific Antigen / Q000097:blood; D011468:Prostatectomy; D011471:Prostatic Neoplasms / Q000097:blood / Q000208:ethnology* / Q000473:pathology / Q000532:radiotherapy* / Q000601:surgery; D011832:Radiation Injuries / Q000208:ethnology* / Q000209:etiology*; D018714:Radiotherapy, Adjuvant / Q000009:adverse effects* / Q000379:methods; D012307:Risk Factors; D014566:Urogenital System / Q000528:radiation effects*; D044465:White People / Q000706:statistics & numerical data*
chemical_list: D014408:Biomarkers, Tumor; D017430:Prostate-Specific Antigen