Objectives-We examined the differential effects of socioeconomic status on colon cancer care and survival in Toronto, Ontario, Canada, and San Francisco, California.Methods-We analyzed registry data for colon cancer patients from Ontario (n=930) and California (n=1014), diagnosed between 1996 and 2000 and followed until 2006, on stage, surgery, adjuvant chemotherapy, and survival. We obtained socioeconomic data for individuals' residences from population censuses.Correspondence should be sent to Kevin Gorey, School of Social Work, University of Windsor, 401 Sunset Ave, Windsor, Ontario, N9B 3P4 gorey@uwindsor.ca. Reprints can be ordered at http://www.ajph.org by clicking the "Reprints/Eprints" link. ContributorsK. M. Gorey conceptualized and supervised the study and led the writing. K. Y. Fung led the analysis. All authors assisted with study design, data analysis, and interpretation and writing. Human Participant Protection CIHR Author Manuscript CIHR Author Manuscript CIHR Author ManuscriptResults-Income was directly associated with lymph node evaluation, chemotherapy, and survival in San Francisco but not in Toronto. High-income persons had better survival rates in San Francisco than in Toronto. After adjustment for stage, survival was better for low-income residents of Toronto than for those of San Francisco. Middle-to low-income patients were more likely to receive indicated chemotherapy in Toronto than in San Francisco.Conclusions-Socioeconomic factors appear to mediate colon cancer care in urban areas of the United States but not in Canada. Improvements are needed in screening, diagnostic investigations, and treatment access among low-income Americans.A study of cancer survival in low-income areas of Toronto, Ontario, and Detroit, Michigan, during the 1980s found advantages among Canadians for common cancers. 1 The Toronto survival advantage was replicated for breast cancer across diverse low-income Canadian and US contexts through the 1990s. 2 Studies of that era, however, were not able to account for differences in stage of disease at diagnosis. More recent studies that accounted for breast cancer stage again found Canadian advantages. [3][4][5][6] In the United States, women with breast cancer who lived in low-income areas waited longer for surgery and adjuvant radiation therapy and were less likely to receive radiation therapy or to survive. Similar disparities between high-and low-income women with breast cancer did not exist in Canada; thus lowincome Canadians fared better across most breast cancer care indices than their US counterparts. More inclusive health insurance in Canada was advanced as the most plausible explanation.Colon cancer care may be an even more important health care performance indicator. The second most frequent cause of cancer death in North America, its prognosis can be excellent with early diagnosis and treatment. 7,8 For several reasons, colon cancer seems particularly instructive for Canada-US cancer care comparisons. First, research on income and colon cancer survi...

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BackgroundWe examined the mediating effects of health insurance on poverty-colon cancer care and survival relationships and the moderating effects of poverty on health insurance-colon cancer care and survival relationships among women and men in California.MethodsWe analyzed registry data for 3,291 women and 3,009 men diagnosed with colon cancer between 1996 and 2000 and followed until 2011 on lymph node investigation, stage at diagnosis, surgery, chemotherapy, wait times and survival. We obtained socioeconomic data for individual residences from the 2000 census to categorize the following neighborhoods: high poverty (30% or more poor), middle poverty (5-29% poor) and low poverty (less than 5% poor). Primary health insurers were Medicaid, Medicare, private or none.ResultsEvidence of mediation was observed for women, but not for men. For women, the apparent effect of poverty disappeared in the presence of payer, and the effects of all forms of health insurance seemed strengthened. All were advantaged on 6-year survival compared to the uninsured: Medicaid (RR = 1.83), Medicare (RR = 1.92) and private (RR = 1.83). Evidence of moderation was also only observed for women. The effects of all forms of health insurance were stronger for women in low poverty neighborhoods: Medicaid (RR = 2.90), Medicare (RR = 2.91) and private (RR = 2.60). For men, only main effects of poverty and payers were observed, the advantaging effect of private insurance being largest. Across colon cancer care processes, Medicare seemed most instrumental for women, private payers for men.ConclusionsHealth insurance substantially mediates the quality of colon cancer care and poverty seems to make the effects of being uninsured or underinsured even worse, especially among women in the United States. These findings are consistent with the theory that more facilitative social and economic capital is available in more affluent neighborhoods, where women with colon cancer may be better able to absorb the indirect and direct, but uncovered, costs of care.

Extremely poor Canadian women were recently observed to be largely advantaged on most aspects of breast cancer care as compared with similarly poor, but much less adequately insured, women in the United States. This historical study systematically replicated the protective effects of single-versus multipayer health care by comparing colon cancer care among cohorts of extremely poor women in California and Ontario between 1996 and 2011. The Canadian women were again observed to have been largely advantaged. They were more likely to have received indicated surgery and chemotherapy, and their wait times for care were significantly shorter. Consequently, the Canadian women were much more likely to experience longer survival times. Regression analyses indicated that health insurance nearly completely explained the Canadian advantages. Implications for contemporary and future reforms of U.S. health care are discussed.

Deregulation of Polo-like kinase (PLK) transcription via promoter methylation results in perturbations at the protein level, which has been associated with oncogenesis. Our objective was to further characterize the methylation profile for PLK1-4 in bone marrow aspirates displaying blood neoplasms as well as in cells grown in vitro. Clinically, we have determined that more than 70% of lymphoma and myelodysplastic syndrome (MDS)/leukemia bone marrow extracts display a hypermethylated PLK4 promoter region in comparison to the normal. Decreased PLK4 protein expression due to promoter hypermethylation was negatively correlated with JAK2 overexpression, a common occurrence in hematological malignancies. In vitro examination of the PLKs under biologically relevant condition of 5% O2 revealed that the highly conserved PLKs respond to lower oxygen tension at both the DNA and the protein level. These findings suggest that PLK promoter methylation status correlates with disease and tumorigenesis in blood neoplasms and could serve as a biomarker.