Race and Insurance Status Affect Risk of Metastasis at Diagnosis in Certain Sarcomas

Soft-tissue sarcomas (STSs) and bone sarcomas account for more than 50 malignant tumor types. Patients with metastatic disease at the time of their diagnosis, compared to those with localized disease, have worse outcomes, including decreased five-year survival—ranging from 10% to 30%, compared to 65% to 80% for patients without metastases. Diagnostic delays may occur because sarcomas do not present early, distinct symptoms, but it is unknown how significant the impact of a delayed diagnosis is on the risk of metastasis and death from sarcoma. A study analyzed how race/ethnicity, socioeconomic status, and insurance type affect metastatic sarcoma at diagnosis.

The researchers queried the Surveillance, Epidemiology, and End Results program to collect data on adult and pediatric patients diagnosed with soft-tissue and bone sarcoma between 2001 and 2015. Patients were stratified into groups based on sarcoma subtype and age: <20 years (pediatric), 20–65 years (adult), and >65 years (older adult). The main outcome was the odds of presenting with metastases at the time of diagnosis.

Final analysis included 47,337 patients (51.4% [n=24,343]) were male; 29,975 (63.3%) were white, 5,673 (12.0%) were black, 7,504 (15.8%) were Hispanic, and 4,185 (8.8%) were American Indian–Alaskan Native and Asian Pacific Islander.

“Among the subtypes evaluated, the prevalence of metastases at diagnosis was highest for alveolar rhabdomyosarcoma (223 patients [47.0%]) among pediatric patients, desmoplastic round cell tumor (134 patients [71.7%]) among adult patients, and gastrointestinal stromal tumors (698 patients [23.4%]) among older adult patients,” said the study authors.

The only subgroup and age combination with a significant incidence trend across socioeconomic status levels was liposarcoma in adults (odds ratio [OR]=0.85; 99% confidence interval [CI], 0.76 to 0.96; P=0.001). Adults with Medicaid or no insurance, compared to non-Medicaid insurance, were more likely to have metastases upon diagnosis in six of the eight sarcoma subtypes evaluated, with the exception only of osteosarcoma and Ewing sarcoma, for which metastasis at diagnosis was not correlated with insurance type. Regardless of insurance and socioeconomic status, black patients, compared to white patients, were more likely to present with metastases upon diagnoses of leiomyosarcoma (OR=1.87; 99% CI, 1.41 to 2.48) and unclassified sarcomas (OR=1.65; 99% CI, 1.01 to 2.67).

The study was published in JAMA Network Open.

“In the current study, we provide evidence that factors related to diagnostic delay, including having Medicaid insurance or no insurance, were associated with an increased risk of presenting with more advanced staged STS in adults, but other factors were more likely associated with metastases at diagnosis for osteosarcoma and Ewing sarcoma, as well as leiomyosarcoma and unclassified sarcomas in non-Hispanic Black adults. These data may be used to guide efforts to detect metastatic sarcoma earlier to improve patient outcomes,” the researchers summarized.