Recent study results show an association between living in an area of socioeconomic deprivation and poor outcomes for patients with cancer who were treated in clinical trials.
Patients with cancer that lived in socioeconomically deprived areas tend to experience worse survival and higher risk of death, according to results of an observational study published in the Journal of Clinical Oncology.
Past studies have confirmed that patients with cancer living in socioeconomically deprived areas tend to have limited access to screening and treatment services and subsequently experience worse outcomes. Despite the fact that clinical trials provide a more uniform standard of patient care, the association between living in these areas and outcomes for patients who have participated in clinical trials has not been examined.
“An important and unresolved question is whether these disparate outcomes remain after accounting for access to quality cancer care,” the study authors wrote.
To determine if a connection could be made, the researchers used data from past cancer treatment clinical trials to examine patient outcomes without the context of inequalities in treatment services.
Using data from the SWOG Cancer Research Network, researchers pooled data from completed phase 3 or large phase 2 trials beginning in 1985, which is when zip code data began to be routinely collected. They then used the Area Deprivation Index (ADI) — a comprehensive index that evaluates 17 indicators of socioeconomic status such as education, employment, housing quality and poverty — to measure levels of socioeconomic deprivation with the participants’ zip codes.
The authors looked at the data of 41,109 patients from 55 trials comprised of 24 cancer-specific cohorts. Compared with trial patients living in the most affluent areas (with an ADI of 0%-20%), patients from the most socioeconomically deprived areas (with an ADI of 80%-100%) had a 28% increased risk of death and worse overall, progression-free and cancer-specific survival. The results were similar after accounting for insurance status, prognostic risk and rural or urban residency. The study authors noted that there were higher rates of older patients, males, Black patients and patients with Medicaid or no insurance as the level of socioeconomic deprivation increased.
Moreover, they noted that previous studies examining the risk of mortality for patients in the lowest socioeconomic categories showed higher risks of mortality. “Taken together, these studies showed about a 60% increased risk of mortality, notably greater than the 28% increased risk in our study,” the authors wrote. “If these studies accurately reflect the outsized risk of poor outcomes for patients with cancer living in the most socioeconomically deprived areas, the comparison suggests that access to protocol-guided care may mitigate half of the negative effects of living in socioeconomically deprived areas.”
They also observed that access to protocol-guided care, as found in a clinical trial, may prove beneficial initially but will not change the tendency toward poor access to health care resources in the long-term. Chronic stress exposure, risky health behaviors associated with living in a lower socioeconomic area (smoking, obesity, physical inactivity, alcohol use and poor diet) and residual differences in prognosis may all also contribute to different clinical outcomes.
The researchers suggested that telehealth models may be beneficial to patients in rural areas that lack access to oncology care resources, as well as patients who do not have the ability to take time off work or pay for childcare to tend to their health care needs. They acknowledged that the COVID-19 pandemic has accelerated the use of telehealth by many care centers, which could benefit patients long-term if sustained. They also noted that better access to adequate health insurance may also prove beneficial to patients.
“Future research should examine whether the etiology of this residual disparity is related to reduced access to supportive care or post-protocol therapy and/or to differences in health status — determined using linked data sources such as Medicare claims — not reflected by protocol staging criteria,” the study authors concluded.
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