In a study of patients with anal cancer, living in low median household income areas was linked with an increased risk of early death.
Published early online in CANCER, a peer-reviewed journal of the American Cancer Society, the findings suggest that socioeconomic inequalities may affect cancer outcomes, especially for highly treatable and curable tumours such as anal cancer.
Squamous cell carcinoma of the anus (SCCA) accounts for 8,200 new cancer cases and more than 1,000 cancer-related deaths in the United States annually.
Its incidence has been notably rising in recent decades, possibly related to changing trends in sexual behaviour combined with known risk factors, such as human papilloma virus and tobacco smoking.
Although advances in the treatment of SCCA have improved survival and cure rates, the benefits may not be shared uniformly among patients of disparate socioeconomic status.
To investigate, a team led by Daniel Becker, MD, of Perlmutter Cancer Center at NYU Langone Health examined whether area-based median household income predicts survival of patients with SCCA.
Their analysis included 9,550 patients with SCCA from 2004-2013 listed in the US Surveillance, Epidemiology, and End Results registry.
Socioeconomic status was defined by census-tract median household income level, and divided into quintiles.
The researchers found that patients living in areas with lower median household income had worse overall survival and cancer-specific survival compared with those in highest income areas.
From the lowest to the higher income levels, the risk of dying was 32%, 31%, 19%, and 16% higher for patients when compared with patients in the very highest quintile of median household income.
When considering only deaths due to cancer, increased risks ranged from 34% down to 22% for the lowest to higher incomes.
Other factors such as older age, black race, male gender, unmarried status, earlier year of diagnosis, higher grade, and later stage were also associated with worse cancer-specific survival.
Income was not associated with a patient's likelihood of initiating radiation therapy.
"Our findings reveal that US residents who have anal cancer and live in areas of poverty have worse survival than those who live in more affluent areas, even after accounting for differences in age, stage, and race," said Dr. Becker. "Anal cancer is often a curable disease, and, in light of the tremendous resources available in US healthcare, we do not believe that poverty should determine cancer outcomes. The ultimate goal is to make sure that all patients receive high quality care, regardless of their wealth or zip code."
Dr. Becker noted that to provide high quality healthcare for all, it will be important to get a better understanding of the factors limiting the successful treatment of anal cancer. "Additional resources are urgently needed to study and address disparities in anal cancer care and outcomes."