title: Incidence of new tumor formation in patients with hereditary retinoblastoma treated with primary systemic chemotherapy: is there a preventive effect?
abstract: OBJECTIVE
  To report the incidence of new tumor formation in hereditary retinoblastoma patients treated with primary systemic chemotherapy.
  
  
  METHODS
  Noncomparative retrospective case series.
  
  
  METHODS
  Fifty-eight consecutive patients with hereditary retinoblastoma treated with primary systemic chemotherapy.
  
  
  METHODS
  The charts of 58 consecutive patients with hereditary retinoblastoma treated between January 1996 and August 2005 were reviewed. Data extracted included gender, age at diagnosis, family history of retinoblastoma, laterality of disease, tumors per eye, Reese-Ellsworth grouping of affected eyes, starting and ending dates for chemotherapy, number of cycles of chemotherapy, chemotherapy regimen, need for external beam radiotherapy and/or enucleation, and development and location (macula, midzone, and periphery) of new tumors after the start of systemic chemotherapy.
  
  
  METHODS
  New tumor formation after treatment with primary systemic chemotherapy.
  
  
  RESULTS
  Of the 58 patients, 48 had bilateral involvement at diagnosis. Median age at diagnosis was 6.6 months. Thirteen patients had a positive family history. Of the eyes with tumor (n = 106) at diagnosis, 52 (49%) were in Reese-Ellsworth groups I to III, whereas 54 (51%) were in group IV or V. Seven patients (12%) with a median age of 1.6 months at diagnosis formed 36 new tumors in 11 eyes after the start of chemotherapy. Median time from initiation of chemotherapy to detection of the first new tumor was 3 months (range, 1-15). Cumulative incidence of new tumor formation at 2 years was 10+/-3%. An age of <6 months at diagnosis, family history of retinoblastoma, and Reese-Ellsworth grouping of I to III were found to correlate significantly with an increased incidence of new tumor formation (P<0.001, P<0.001, and P = 0.021, respectively). Median follow-up for all patients was 5 years (range, 1-10.1).
  
  
  CONCLUSIONS
  New tumors continue to form in patients with hereditary retinoblastoma despite treatment with primary systemic chemotherapy. Younger patients and those with a positive family history are more likely to have new tumors formed. However, chemotherapy may impact small previously undetected lesions by slowing their growth and facilitating later focal consolidation.
authors.affiliation: Department of Ophthalmology/Hamilton Eye Institute, University of Tennessee Health Science Center, Memphis, Tennessee 38163, USA. mwilson5@utmem.edu
authors.forename: Matthew W
authors.initials: MW
authors.lastname: Wilson
authors.forename: Barrett G
authors.initials: BG
authors.lastname: Haik
authors.forename: Catherine A
authors.initials: CA
authors.lastname: Billups
authors.forename: Carlos
authors.initials: C
authors.lastname: Rodriguez-Galindo
mesh_terms: D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D002675:Child, Preschool; D005260:Female; D006801:Humans; D015994:Incidence; D007223:Infant; D008297:Male; D016609:Neoplasms, Second Primary / Q000175:diagnosis / Q000209:etiology*; D019572:Retinal Neoplasms / Q000188:drug therapy / Q000209:etiology* / Q000235:genetics; D012175:Retinoblastoma / Q000188:drug therapy / Q000209:etiology* / Q000235:genetics; D012189:Retrospective Studies; D013997:Time Factors