Increasing incidence of retinoblastoma?

T1 Gd-enhanced compared with CISS sequences in retinoblastoma: superiority of T1 sequences in evaluation of tumour extension

BACKGROUND

As adequate therapy for retinoblastoma in young children depends on infiltration of extra-retinal structures, diagnostic modalities play an essential role.

METHODS

In this widely extended study, 80 children with retinoblastoma were studied with MRI (standard fat-suppressed Gd-enhanced T1, T2 thin-slice sequences (additionally with small loop surface coil), constructive interference in steady state (CISS) sequence covering the orbita). The images were analysed by two blinded neuroradiologists. Histology was used as the gold standard.

RESULTS

MRI assumed infiltration of extra-retinal structures in 13 of 80 patients of which ten were confirmed by histology. Affected extra-retinal structures were: optic nerve (five, of which two were on CISS and three on T1 with higher image resolution using the surface coil), scleral infiltration (five, of which four on CISS and T1) and ciliary body infiltration (one on CISS and T1). Another 61 enucleated patients did not have any extra-retinal infiltration in histology. The CISS sequence with multiplanar reconstruction was mainly helpful in revealing exact three-dimensional tumour extension with excellent clinical acceptance and pre-surgical planning but T1 fat-suppressed Gd-enhanced images were superior in revealing exact tumour extension.

CONCLUSION

CISS sequences allow to produce excellent anatomical images and to perform multiplanar reconstruction to better demonstrate tumour extension. However, T1-weighted sequences after contrast application are more sensitive (60 versus 40%) in detecting infiltration of the optic nerve but equal in detecting scleral infiltration.

Risk factors for metastasis in retinoblastoma

Children with retinoblastoma typically survive their cancer due to advances in early diagnosis and treatment. Despite this success, risk factors persist for metastasis that are thought to be related to patient age, sex, laterality, treatment, genetics, histopathology, and extraocular extension. This review has found that invasion of the uvea, orbit, and optic nerve continue to be the most important predictors of metastatic retinoblastoma. Bilaterality and delays in diagnosis are also important factors. We examine molecular and genetic studies that offer the potential of predicting which tumors are likely to metastasize, which will recur within the eye, and which will undergo senescence. In this review, we describe which clinical evaluations, genetic studies, and histopathologic evaluations of retrieved specimens are currently used widely. This review has been performed to help those caring for patients with retinoblastoma and to aid informed consent.

Incidence and survival of retinoblastoma in The Netherlands: a register based study 1862-1995

AIM

The aim of this study was to determine the (time trends in) incidence and survival of hereditary (familial and sporadic) and non-hereditary retinoblastoma for male and female patients born in the Netherlands between 1862 and 1995.

METHOD

The national retinoblastoma register was updated and now consists of 955 patients. The missing dates of death were obtained from the municipal registers and the Central Bureau of Genealogy in The Hague. Mortality was compared with the Dutch vital statistics.

RESULTS

From 1862 to 1995 no significant differences in incidence for retinoblastoma were found in the hereditary subgroups. Further, no significant differences between males and females were found, both overall and in the hereditary subgroups. The average incidence of retinoblastoma increased until 1944, probably due to incompleteness of the register, and stabilised after 1945 (1 per 17000 live births). From 1900 to 1995 the standardised mortality ratio increased for hereditary retinoblastoma patients from 2.9 to 9.0 and decreased for non-hereditary retinoblastoma patients from 1.9 to 1.0.

CONCLUSION

Although survival for retinoblastoma was significantly better after 1945 than before, in comparison with the Dutch population the mortality between 1900 and 1990 increased for the hereditary and decreased for the non-hereditary retinoblastoma patients.

Thirty years of retinoblastoma (1960-89): changing patterns of incidence

This study of a 30-year population-based dataset investigates further an earlier observation that the incidence of sporadic bilateral retinoblastoma appeared to be increasing in recent years in the West Midlands Health Authority Region (WMHAR). Stringent measures were applied to ensure complete ascertainment of all cases of retinoblastoma in children in the region, resulting in a total of 117 cases diagnosed during the period 1960-89 in the WMHAR. Hospital case notes were abstracted and follow-up data obtained. Incidence rates were calculated. The overall incidence remained constant over the 30-year period, but that of sporadic bilateral tumours increased, with a corresponding decline in familial cases. There was a statistically significant excess seen in Asian children.