title: Incidences, Trends and Long Term Outcomes of Retinoblastoma in Three Cancer Registries, Thailand.
abstract: BACKGROUND
  Retinoblastoma (RB) is rare, albeit the most common primary intraocular malignancy among children. To elucidate the true incidence, trend and survival, we studied incidences and trends of retinoblastoma in a large population with long-term follow-up using data from 3 population-based cancer registries.
  
  
  OBJECTIVE
  To describe the incidence, trends and survival of RB between 1990 and 2009 in Khon Kaen, Songkhla and Chiang Mai, Thailand.
  
  
  METHODS
  We sourced the data from the cancer registries in Khon Kaen, Songkhla and Chiang Mai on children with retinoblastoma, diagnosed between 1990 and 2009. Retinoblastoma was defined as per the International Classification of Disease for Oncology version 3 using the code 9510/3. Incidence was analyzed using the standard method with the criteria of the International Association of Cancer Registries. The Kaplan-Meier method was applied to calculate cumulative survival. Trends were calculated using the log rank test.
  
  
  RESULTS
  We identified 75 cases of children between 0 and 15 years of age diagnosed with RB (Khon Kaen 31, Chiang Mai 20, Songkhla 24). Males and females were equally affected. The most common age group was 0-4 years. The morphological verification of the disease was 90.7%. The respective ASR in Khon Kaen, Chiang Mai and Songkhla was 4.4, 4.0 and 4.6 per million; for which the overall ASR for all 3 areas was 4.3 per million. The respective trend in incidence was 4, 2.8, 5.8 and 5.4 during 1990-4, 1995-9, 2000-4 and 2005-9. Overall, incidence trended gradually upward by 2% annually. The respective survival rate in Khon Kaen, Chiang Mai and Songkhla was 50, 40 and 75% (differences not significantly different at p=0.14) and the overall survival for all centers was 60%.
  
  
  CONCLUSIONS
  Over the last two decades, the incidence and overall survival of retinoblastoma has increased. The ASRs and survival in Thailand were less than those in resource-rich countries.
authors.affiliation: Department of Pediatrics, 2Cancer Unit, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand E-mail : suraponwiangnon@gmail.com.
authors.forename: Piyathida
authors.initials: P
authors.lastname: Wongmas
authors.forename: Arunee
authors.initials: A
authors.lastname: Jetsrisuparb
authors.forename: Patcharee
authors.initials: P
authors.lastname: Komvilaisak
authors.forename: Krittika
authors.initials: K
authors.lastname: Suwanrungruang
authors.forename: Worawut
authors.initials: W
authors.lastname: Choeyprasert
authors.forename: Hutcha
authors.initials: H
authors.lastname: Sriplung
authors.forename: Surapon
authors.initials: S
authors.lastname: Wiangnon
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D015994:Incidence; D007223:Infant; D007231:Infant, Newborn; D053208:Kaplan-Meier Estimate; D008297:Male; D012042:Registries; D019572:Retinal Neoplasms / Q000453:epidemiology* / Q000401:mortality; D012175:Retinoblastoma / Q000453:epidemiology* / Q000401:mortality; D015996:Survival Rate; D013785:Thailand / Q000453:epidemiology; D013997:Time Factors