Study Finds Racial, Socioeconomic Disparities in Uveal Melanoma Treatment

Racial, ethnic, and socioeconomic status (SES) disparities exist in uveal melanoma (UM) treatment and survival, according to a study published in JAMA Ophthalmology.¹

UM is a relatively rare but deadly cancer and is primarily found in the Caucasian population. The cancer is also the most common primary intraocular tumor in adults, with an estimated incidence of 5.1 cases per 1 million individuals each year, according to an article in Nature’s Eye journal.²

“Histopathologic studies have reported that the clinical and genetic course of non-white patients with UM may be different than in white patients, with Asian Indian individuals presenting younger, Mexican-Mestizo patients showing a previously unreported polymorphism, and Hispanic patients presenting with unique symptoms and broader-based tumors,” the JAMA Ophthalmology authors wrote.

In a retrospective cohort study, the researchers set out to determine whether race, ethnicity, or lower SES is associated with increased odds of primary enucleation or decreased survival.

Data were collected from the National Cancer Institute’s Surveillance, Epidemiology, and End Results (SEER) registries, representing 28% of the US population. International Classification of Diseases for Oncology, Third Edition codes showed 4475 individuals exhibited the condition between 2004 and 2014.

The SEER database reported races as white, black, Asian, Pacific Islander, American Indian/Alaska Native, or other, while ethnicity was reported as Hispanic or non-Hispanic. Researchers combined all non-white and Hispanic patients into 1 group for comparison against non-Hispanic white patients, due to the fact UM is uncommon in nonwhite patients. SES was estimated using composite scores from the Yost index via information from the patient’s Census tract.

Treatment of UM was classified by codes reflecting radiotherapy only, enucleation only, radiotherapy and enucleation, or no/unknown.

Of the individuals who received treatment, 4130 were non-Hispanic and 345 were nonwhite. Ninety-four nonwhite individuals underwent enucleation without radiotherapy and 804 non-Hispanic patients received primary enucleation. The majority of non-Hispanic white and nonwhite cohorts were treated with radiotherapy only.

The analysis revealed:

• More patients (n = 264; 27.0%) in the lower tertile of SES classification underwent enucleation without radiotherapy compared with those in the middle (n = 351; 23.4%) and upper (n = 283; 14.2%) tertiles
• Most patients in the upper (n = 1510; 75.5%), middle (n = 1007; 67.2%), and lower (n = 625; 63.9%) tertiles received radiotherapy only (P&thinsp;<&thinsp;.001)
• Patients who underwent enucleation without radiotherapy were more likely to be of nonwhite race/ethnicity (odds ratio [OR], 1.45; 95% CI, 1.12-1.88)
• Patients of middle SES (OR, 1.86; 95% CI, 1.56-2.21) or lower SES (OR, 2.21; 95% CI, 1.82-2.68) were more likely to receive only enucleation compared with patients of upper SES
• Despite overall decreases in isolated enucleation rates, nonwhite individuals consistently exhibited higher rates of primary enucleation than non-Hispanic white patients, as did patients of lower or middle SES compared with those of upper SES (2004-2009: race/ethnicity, P&thinsp;=&thinsp;.01; SES, P&thinsp;<&thinsp;.001; 2010-2014: race/ethnicity, P&thinsp;=&thinsp;.11; SES, P&thinsp;<&thinsp;.001)

A total of 589 patients (13.2%) died during the study period and disease-specific survival estimates were found to be similar across racial/ethnic groups. Lower SES was associated with a decreased 5-year all-cause survival, while both disease-specific and all-cause 1-year and 5-year survival estimates had minimal racial/ethnic variation. Increased mortality was also associated with older age at diagnosis, advanced stage, and treatment with isolated enucleation.

“While overall rates of primary enucleation decreased by 10.4 percentage points during the study period, non-white and socioeconomically disadvantaged patients consistently received primary enucleation in higher proportions than their white and socioeconomically advantaged counterparts,” the authors wrote.

Researchers argued that given the limited difference in survival between radiotherapy and enucleation, radiotherapy is preferred to treat UM. A potential explanation as to why individuals with lower SES have an increased likelihood of receiving primary enucleation is that these patients face greater challenges receiving health care. Thus, treatment may be delayed, resulting in more advanced disease presentation.

“Given the consequences of enucleation, including postoperative vision loss, decreased quality of life, decreased functionality, and increased perceived stigma, efforts should be made to appropriately reduce differences in enucleation rates across populations,” the authors concluded.

References

1. Rajeshuni N, Zubair T, Ludwig CA, et al. Evaluation of racial, ethnic, and socioeconomic associations with treatment and survival in uveal melanoma, 2004-2014. JAMA Opthalmol. Published online July 2, 2020. doi:10.1001/jamaophthalmol.2020.2254

2. Kaliki S, Shields CL. Uveal melanoma: relatively rare but deadly cancer. Eye. 2017;31:241-257. doi:10.1038/eye.2016.275