Colorectal Cancer Disparity in African Americans

Abstract

African Americans have the highest incidence and mortality rates of colorectal cancer (CRC) of any ethnic group in the United States. Although some of these disparities can be explained by differences in access to care, cancer screening, and other socioeconomic factors, disparities remain after adjustment for these factors. Consequently, an examination of recent advances in the understanding of ethnicity-specific factors, including genetic and environmental factors relating to risk of CRC, the biology of CRC progression, and the changes in screening and mortality, is important for evaluating our progress toward eliminating the disparities. An overarching limitation in this field is the number and sample size of studies performed to characterize the etiological bases of CRC incidence and mortality in African Americans. Despite this limitation, significant differences in etiology are manifest in many studies. These differences need validation, and their impacts on disparities need more detailed investigation. Perhaps most heartening, improvements in CRC screening can be attributed to the smallest difference in CRC incidence between African Americans and whites since the late 1980s. Cancer mortality, however, remains a persistent difference.

<p>microRNA-877 inhibits malignant progression of colorectal cancer by directly targeting MTDH and regulating the PTEN/Akt pathway</p>

“…Despite tremendous progress in the diagnosis and treatment of cancer, the prognosis of patients with CRC remains dissatisfactory owing to the high rate of tumor recurrence and metastasis 4. Extensive evidence demonstrates the involvement of multiple factors, such as the inactivation of tumor suppressor genes, activation of oncogenes, and mutation of mismatch repair genes, in CRC pathogenesis; however, the detailed mechanisms are not yet completely understood 5–7. Hence, it is of considerable importance to improve our understanding of the molecular mechanisms underlying CRC occurrence and development to provide new strategies for cancer diagnosis, therapy, and prevention.…”

It’s contrary – comorbidity does not affect survival of South Africans with colorectal cancer: An analysis from the Colorectal Cancer in South Africa cohort

“…[36][37][38][39][40][41] This trend of earlier age at presentation and poorer outcomes observed in SSA has also been observed in African Americans compared with non-Hispanic white Americans. [42] Although comorbidity did not affect OS in the present study, our analysis produced other unexpected findings that warrant further discussion. It is well described that outcomes are universally poor in patients who present with an advanced (distant) stage of CRC, in all income settings.…”

“…The exact points of contact patients have with the healthcare system that delay management therefore need to be identified and addressed. South Africa (present study) 74.0 (69.0 -78.0) 89.0 (81.0 -94.0) 81.0 (73.0 -87.0) 61.0 (53.0 -68.0) Mumbai, India [43] 63.4* 78.2* 69.4* 31.3* China [44] 75.1* ---Ghana [37] 64.0 (56.2 -71.1) ---Nigeria [36] 64.0* ---HICs Denmark [42] 80.…”

Association of genetic ancestry with colorectal tumor location in Puerto Rican Latinos

“…This finding is in contrast with the reported literature that has consistently found an increase in the diagnosis of proximal location of colorectal tumors in African American and Latino patients [35–39]. The localization of colorectal tumors is important since proximal tumors are more likely to be missed during screening colonoscopy [40] and are associated with worse prognosis [38]. In addition, rectal tumors are treated with radiation therapy, which is not generally recommended for proximal tumors [41].…”