A new analysis from Canada has found that cancer patients from poorer communities have a greater chance of dying prematurely than individuals from more affluent backgrounds even though cancer stage at time of diagnosis is similar across socioeconomic groups. Published early online in Cancer, a peer-reviewed journal of the American Cancer Society, the study indicates that efforts are needed to understand and reduce disparities in the survival of cancer patients from different socioeconomic groups.
Christopher Booth, MD, FRCPC, of the Queen's University Cancer Research Institute in Ontario, Canada led a team that analyzed all cases of breast, colon, rectal, non-small cell lung, cervical, and laryngeal cancer diagnosed in Ontario, Canada from 2003 to 2007, as identified through the Ontario Cancer Registry. Patients were divided into groups based on median household income reported in the 2001 Canadian census.
The investigators observed only very modest differences in cancer stage at the time of diagnosis across socioeconomic groups, contrasting with much of the existing literature. "It is plausible that the lack of a strong association between stage of disease and socioeconomic status in our study relates to the presence of universal health coverage in Ontario which may facilitate access to primary care physicians and/or cancer screening," said Dr. Booth.
However, the researchers found that despite universal healthcare, significant differences in survival across socioeconomic groups persist in Ontario: overall and cancer-specific survival of patients from poorer communities was lower than that of patients residing in more affluent neighborhoods. "Contrary to what has been reported in studies from the U.S., we have found that stage of cancer at time of diagnosis does not account for any substantial component of the difference in survival across social groups," said Dr. Booth. Instead, factors such as differences in cancer biology, the presence of other illnesses, access to treatment, and quality of care might play a role. The authors noted that additional work is needed to better understand these factors and to develop strategies to reduce disparities in the survival of patients with cancer.
"The impact of socioeconomic status on stage of cancer at diagnosis and survival: a population-based study in Ontario, Canada." Christopher M. Booth, Gavin Li, Jina Zhang-Salomons, and William J. Mackillop. CANCER; Published Online: August 2, 2010 (DOI: 10.1002/cncr.25427).