Impact of socioeconomic status on extent of disease at diagnosis and cancer and ocular outcomes in retinoblastoma: A population-based analysis
Reporter: Jacob Shabason, MD
The Abramson Cancer Center of the University of Pennsylvania
Last Modified: June 6, 2013
Presenter: Bao Truong, BS
Presenter's Affiliation: Dana-Farber Cancer Institute, Boston, MA
Abstract #: 10011
- Retinoblastoma is the most common intraocular cancer of childhood, and accounts for 3% of all pediatric malignancies.
- The most common presenting sign of retinoblastoma is leukocoria, which can be easily detected with the examination for a red reflex.
- Therefore, primary care physicians play a vital role in the diagnosis of retinoblastoma through performance of routine screening evaluating for a red reflex.
- There is a strong correlation between early diagnosis and improved clinical outcome in retinoblastoma.
- If the tumor is identified when small and has not yet extended outside of the retina, patients can be treated with globe preservation therapy.
- Tumors identified later with vitreous or sub-retinal seeding, however, typically require enucleation.
- Although appropriate local therapy generally results in long-term survival, delayed diagnosis tends to lead to more extensive disease and less of a chance for eye preservation or cure.
- Barriers to proper primary care screening may delay the diagnosis of retinoblastoma and affect prognosis.
- In this SEER registry study the authors analyze the impact of socioeconomic status and ethnicity on the extent of disease, as well as cancer and ocular outcomes.
Materials and Methods
- Eighteen SEER registries from 2000-2009 were searched and all retinoblastoma cases (0-9 years) were included in the analysis.
- Diagnosis, staging, treatment, gender, race, ethnicity and county of residence were collected on each patient.
- The county-based disparity variables analyzed included poverty level, education attainment, language isolation, crowding, and percentage of immigrants.
- The cut-off values were defined as the median values for the cohort of patients.
- Relative survival was calculated using Ederer II method and estimates were compared using Z-score.
- 755 case of retinoblastoma were identified and included in this study.
- The percentage of patients with extraocular disease was consistently higher in US counties with lower socioeconomic indications, including:
- Higher vs. lower poverty status (29.3% vs. 22.1%, p=0.028)
- Lower vs. higher education attainment (30.6% vs. 22.7%, p=0.003)
- Higher vs. lower crowding (33.2% vs. 18.1%, p<0.001)
- Higher vs. lower language isolation (32.2% vs. 19.3%, p<0.001).
- Higher vs. lower percentage of immigrants (30.1% vs. 21.4%, p=0.008).
- In terms of racial associations, Hispanic patients had significantly higher percentage of extraocular disease compared to other races (35.2% vs. 20.9%, p<0.001).
- Worse ocular outcomes, as measured by a higher percentage of enucleation, were associated with counties with low education attainment (75.4% vs. 67.4%, p=0.025), and with Hispanic origin (77% vs. 68.6%, p=0.019).
- Decreased survival was associated only with the variable of language isolation (p=0.016), but not with Hispanic origin or other socioeconomic indicators.
- There are significant disparities in the care and outcomes of pediatric patients with retinoblastoma.
- Lower socioeconomic factors are associated with more extensive disease, presumably from decreased access to primary care physicians and therefore delayed diagnosis.
- Hispanic patients in particular tend to have more advanced disease and higher enucleation rates.
- The only factor associated with impaired survival is language isolation.
- Early diagnosis of retinoblastoma by primary care physicians is vital for improved clinical outcomes and may permit opportunities for early interventions that can avoid the morbid procedure of enucleation.
- Socioeconomic and ethnic barriers to care place patients who live in certain underserved communities at higher risk for presenting with later stage disease.
- This study indicates a need for improved screening for retinoblastoma in underserved populations and further work is necessary to try to improve this access to care.
- When examining the risk factor of race it is sometimes difficult to separate associations due to socioeconomic factors or genetic causes.
- The association of more extensive disease in Hispanic populations warrants further investigation into possible genetic causes that may predispose patients to more aggressive disease.