E. M. Nicholls (1927–2011) was a humanist, medical practitioner, human biologist, geneticist and, above all, a teacher, as well as a husband and father. He believed that he had made a fundamental contribution to the two-hit model of cancer formation. This hypothesis is associated with retinoblastoma, in particular. Nicholls presented it through his observations on neurofibromatosis. He received little credit for what he believed was his most original contribution to medical science. This note attempts to redress the balance in his favor.

Objectives: The aim of this study was to conduct a systematic review of the evidence for treatments for retinoblastoma in children.

Methods: Seventeen electronic databases were searched. Two reviewers independently selected studies. Studies of participants diagnosed with childhood retinoblastoma, any interventions, and all clinical outcomes were eligible. Randomized and nonrandomized controlled trials and cohort studies with clear comparisons between treatment groups were included. Methodological quality was assessed.

Results: Thirty-one observational comparative studies were included, of which twenty-seven were retrospective. The methodological quality was generally poor, with a high risk of selection bias in all studies. Although there were high levels of treatment success in many of the studies, due to the limitations of the evidence identified, it was not possible to make meaningful and robust conclusions about the relative effectiveness of different treatment approaches for retinoblastoma in children.

Conclusions: Good quality randomized controlled trials are required. Where controlled trials are not feasible, only high quality prospective, nonrandomized studies should be given consideration, due to the generally higher risk of bias in retrospective studies.

Retinoblastoma (Rb) is the most common primary ocular malignancy of children and is caused by a mutation in the gene RB1. Approximately 40% of cases are associated with one or more constitutional mutations, and are therefore heritable, whereas the other 60% are sporadic. Rb is exclusively found in young children. In some cases, Rb tumours metastasise to extraocular organs including bone, lung and brain. Although there is no effective treatment for metastatic disease, non-metastatic cases can be cured by removal of the eye (enucleation). Newer treatment strategies emphasise salvaging the affected eye whenever possible. Animal models of Rb have been developed with xenograft and transgenic techniques. Each model has both strengths and weaknesses for exploring the mechanisms of disease development and progression and the efficacy of new treatment strategies.

A case is presented of a patient with bilateral retinoblastoma, treated at infancy with surgery, chemotherapy and radiotherapy, who subsequently developed at least four additional histologically distinct malignancies: a Ewing sarcoma of the left fibula, two extraskeletal osteosarcomas of the left lower extremity, a mucoepidermoid carcinoma of the right parotid gland and a squamous cell carcinoma of the left paranasal cavity.

In addition to retinoblastoma, patients with a germline RB-1 mutation are at high risk of second primary malignancies. An additive carcinogenic effect of cytotoxic therapy in these patients has been assumed. Patients with hereditary retinoblastoma should be under life-long follow-up programmes including a regular head and neck examination for detection of new primaries, especially in the radiation field of the presenting retinoblastoma.

The polymorphisms of constitutive heterochromatin regions, present on chromosomes 1, 9, 16 and Y, are inherited in a Mendelian fashion. The C-band heteromorphism has been reported to be associated with various types of cancer. Heterochromatin is considered to play a role in protecting genome against the mutagens. Changes in the quantity and proportion of the different types of satellite DNA might increase the genetic susceptibility in people with heterochromatic variations, which in turn cause chromosome instability and predispose the individual to cancer. We report a case of bilateral retinoblastoma with complete absence of pericentromeric heterochromatin on one of the chromosomes number 9. A similar deficiency of pericentromeric heterochromatin on chromosome number 9 and 16 has been reported in a phenotypically normal individual and a Down syndrome case, respectively. This deficiency was found to be inherited from the father in all the three cases. Complete absence of pericentromeric heterochromatin of chromosome 9 is not being reported in association with cancer syndromes. Further studies are necessary to understand the role of this factor in normals and in those with cancer susceptibility, specially with retinoblastoma and the paternal origin of this deficiency.

The c-fos promoter is negatively regulated by the retinoblastoma (Rb)-suceptibility-gene- encoded protein as well as by other genes involved in the control of transcription, cell cycle regulation and neoplastic transformation. We have examined by immunohistochemistry the c-Fos and c-Jun proteins in five cases of retinoblastoma in order to evaluate eventual alterations in their expression in vivo, possibly related to a gene mutation or to loss of Rb negative control.