Colorectal cancer in African Americans

Patterns of care for adjuvant therapy in a random population-based sample of patients diagnosed with colorectal cancer

OBJECTIVES

Over the past decade, clinical trials have proved the efficacy of treatments for colorectal cancer (CRC). This study tracks dissemination of these treatments for patients diagnosed with stage II and III disease and compares risk of death for those who received guideline therapy to those who did not.

METHODS

We conducted a stratified randomly sampled, population-based study of CRC treatment trends in the United States. Multivariate models were used to explore patient characteristics associated with receipt of treatments. We pooled data with a previous study-patients diagnosed in 1987-1991 and 1995. Cox proportional hazards models were used to assess observed cause-specific and all-cause mortality.

RESULTS

In 2000, guideline therapy receipt decreased among stage III rectal cancer patients, but increased for stage III colon and stage II rectal cancer patients. As age increased, likelihood of receiving guideline treatment decreased (p < 0.0001). Overall, race/ethnicity was significantly associated with guideline therapy (p = 0.04). Rectal patients were less likely to have received guideline treatment. Consistent with randomized clinical trial findings, all-cause mortality was lower in patients who received guideline therapy, regardless of Charlson comorbidity score.

CONCLUSIONS

Mortality was decreased in patients receiving guideline therapy. Although, rates of guideline-concordant therapy are low in community clinical practice, they are apparently increasing. Newer treatment (oxaliplatin, capecitabine) started to disseminate in 2000. Racial disparities, present in 1995, were not detected in 2000. Age disparities remain despite no evidence of greater chemotherapy-induced toxicity in the elderly. More equitable receipt of cancer treatment to all segments of the community will help to reduce mortality.

Colorectal cancer in U.S. adults younger than 50 years of age, 1998-2001

BACKGROUND

Colorectal cancer (CRC) incidence rates are increasing among persons younger than 50 years of age, a population routinely not screened unless an individual has a high risk of CRC. This population-based study focuses primarily on describing the CRC burden for persons in this age group.

METHODS

The data used for this study were derived from the National Program of Cancer Registries (NPCR) and Surveillance, Epidemiology, and End Results (SEER) surveillance systems. Age-adjusted incidence rates, rate ratios, and their corresponding 95% confidence intervals were calculated.

RESULTS

CRC is ranked among the top 10 cancers occurring in males and females aged 20-49 years regardless of race. Persons younger than 50 years were more likely to present with less localized and more distant disease than do older adults. Among younger adults, age-adjusted incidence rates for poorly differentiated cancers were twice as high as rates for well-differentiated cancers. Incidence rates for poorly differentiated cancers were 60% higher than that for well-differentiated cancers diagnosed in older adults. Rates were significantly higher for blacks and significantly lower for Asians/Pacific Islanders when compared with that for whites for the most demographic and tumor characteristics examined.

CONCLUSIONS

This study confirms the findings of previous population-based studies suggesting that younger patients present with more advanced disease than do older patients. This study also identifies racial and ethnic disparities in CRC incidence in this population. These findings suggest the need for additional studies to understand the behavior and etiology of CRC in blacks.

CDC-funded intervention research aimed at promoting colorectal cancer screening in communities

BACKGROUND

Although strong scientific evidence has shown that screening for colorectal cancer saves lives, most U.S. adults who are at the recommended age are not being screened. Prior studies suggest that barriers to routine screening vary by race, ethnicity, socioeconomic status, urban/rural residence, health insurance status, and factors related to health care providers and the health care environment. Relatively few studies, however, have identified and tested intervention approaches to promote routine colorectal cancer screening among diverse populations.

METHODS

The Division of Cancer Prevention and Control at CDC has funded ongoing projects to develop and test interventions to promote routine colorectal cancer screening among medically underserved populations in Appalachia, the Lower Rio Grande Valley in Texas, the High Plains region of Colorado, and other U.S. communities.

RESULTS

This article provides an overview of colorectal cancer screening intervention studies currently funded by CDC that focus on a wide range of populations, including medically underserved persons who live in predominately rural areas, Hispanic and non-Hispanic persons, urban African Americans, persons with low health literacy, and persons enrolled in managed care organizations.

CONCLUSIONS

These CDC-funded intervention research projects are likely to contribute importantly to evidence about what works to promote colorectal cancer screening in diverse U.S. communities. .

Screening for colorectal cancer in average-risk populations

Screening average-risk populations for colorectal cancer can reduce the incidence and mortality of colorectal cancer. Effectiveness depends on programmatic adherence and quality. This review discusses the evidence supporting the use of currently available screening tests. The discussion specifically focuses on programmatic issues and highlights the importance of quality assurance in each program.

Racial differences in colorectal cancer test use by Medicare consumers

BACKGROUND

Lower use of colorectal cancer (CRC) screening has been suggested as a factor in higher rates of CRC incidence and mortality among African Americans. Racial differences in colorectal cancer test use are not well understood.

METHODS

The study sample included respondents aged 50 to 80 to a 2001 telephone survey of Medicare consumers from two states. The analyses, initiated in 2004, were limited to respondents with no history of CRC (n = 1901). Three CRC tests were examined: fecal occult blood tests (FOBTs), sigmoidoscopy, and colonoscopy. Type of testing and testing according to Medicare coverage intervals by race were compared. Odds ratios (ORs) and 95% confidence intervals (CIs) were obtained from unadjusted and adjusted models to assess the independent associations between race and test use.

RESULTS

Adherence to the Medicare-covered intervals for CRC tests was low (56.8% for whites, 39.1% for African Americans), and did not significantly differ by race after adjustment. African Americans were, however, significantly less likely to have ever been tested (OR = 0.48, 95% CI = 0.33-0.70) and more likely to have had an endoscopic test than an FOBT (OR = 3.06, 95% CI = 1.70-5.51).

CONCLUSIONS

The type of test used to screen for colorectal cancer has important implications for compliance with recommended screening intervals. Understanding reasons for racial differences in CRC test use may help identify approaches to increasing test use in the Medicare population.

Colon pathology detected after a positive screening flexible sigmoidoscopy: a prospective study in an ethnically diverse cohort

OBJECTIVES

Although the association between distal neoplasia on sigmoidoscopy and proximal colonic pathology on follow-up colonoscopy has been well-described, it is not known if these findings are consistent across ethnic groups. The aim of this study was to evaluate ethnic variations in the prevalence of proximal neoplasia on follow-up colonoscopy after a neoplastic lesion is found on sigmoidoscopy.

METHODS

Consecutive asymptomatic patients at average-risk for colorectal cancer who were referred for screening flexible sigmoidoscopy were prospectively enrolled. Colonoscopy was recommended for all patients with a polyp on flexible sigmoidoscopy, regardless of size. Advanced neoplasms were defined as adenomas > or = 10 mm in diameter or any adenoma, regardless of size, with villous histology, high-grade dysplasia, or cancer.

RESULTS

Among the 2,207 patients who had sigmoidoscopy, 970 were Caucasian, 765 were African American, 395 were Hispanic, and 77 were Asian. The prevalence of neoplasia in the distal colon was 12.6% in Caucasians, 11.2% in African Americans, 15.9% in Hispanics, and 24.7% in Asians (p = 0.002). Of the 290 patients with neoplastic lesions on sigmoidoscopy, follow-up colonoscopy identified neoplasms in the proximal colon in 63.9% of Caucasians, 59.3% of African Americans, 66.7% of Hispanics, and 26.3% of Asians (p = 0.01). Advanced neoplasms in the proximal colon were highest in African Americans (34.9%) and lowest in Asians (10.5%).

CONCLUSIONS

In our study population, Asians demonstrated a higher prevalence of distal colonic neoplasia and a lower prevalence of proximal colonic neoplasia compared to non-Asians. Future studies should explore ethnic variation in colonic neoplasia prevalence and location since ethnic variation could lead to tailored colorectal cancer screening strategies.

The polyp detection rate of colonoscopy: a national study of Medicare beneficiaries

National-level data on the proportion of colonoscopies in routine practice that result in polyp detection are limited. Our goal was to determine the diagnostic yield of colonoscopy among population subgroups. We reviewed Medicare claims data for all fee-for-service beneficiaries 65 years or older who underwent colonoscopy in 1999. With the use of diagnosis and procedure codes, the proportion of procedures with polyps was estimated. Three different criteria for polyp detection were used. Approximately 1.8 million colonoscopy procedures were identified. Depending on the specific criteria used, 23.9% to 35.7% of examinations noted polyps. The detection rate was highest in younger patients, men, and whites. The apparent yield of colonoscopy in terms of polyp detection is at least 24%. These data may be informative in predicting resource allocation for therapeutic procedures associated with colonoscopy. Future studies should determine the use and yield of serial colonoscopies for polyp surveillance.

Race, gender, and colorectal cancer screening

Colorectal cancer (CRC) screening in asymptomatic, average-risk populations can reduce mortality and incidence of CRC. The United States Preventive Services Task Force, the American Cancer Society, and the Multi-Society Task Force all recommend initiation of screening at the age of 50 yr for men and women of all races, with an identical menu of screening options. However, there are important differences in risk based on gender, race, and ethnicity. These differences could influence the timing of initiation of screening, and the most optimal form of screening test. This commentary discusses the basis for these differences, and proposes that we should consider customization of screening based on gender, race, and ethnicity.

Inappropriate colorectal cancer screening: findings and implications

OBJECTIVES

Inclusion of colorectal cancer screening as a performance measure in the Veterans Health Administration (VHA) health system appears to have improved screening rates but may have also increased inappropriate screening. Our aim was to ascertain whether the fecal occult blood test (FOBT) was being ordered appropriately.

METHODS

We examined records of 500 consecutive primary care patients at a single VHA facility for whom FOBT had been ordered to determine whether the FOBT was appropriate and, if not, the reason why.

RESULTS

We found that 18% of the sample had severe comorbid illness, 13% had signs or symptoms of gastrointestinal blood loss, 7% had a history of colorectal neoplasia or inflammatory bowel disease (high risk), 5% had undergone colonoscopy within prior 5 yr, and 3% were younger than 50 yr of age. Overall, 35% of the patients had at least one reason that the FOBT was inappropriate and at least 19% of the patients should not have undergone any colorectal cancer test for screening or diagnosis.

CONCLUSIONS

The FOBT order was inappropriate in a third of the sample, most commonly because of a documented life-limiting comorbidity. In addition, data suggested that FOBT was being used for diagnosis instead of screening. Screening patients unlikely to live long enough to develop and die from colorectal cancer provides no benefit and places these individuals at unjustifiable risk. Additionally, inappropriate screening utilizes resources that could be used to improve screening and follow-up for eligible individuals.

Outcomes among African-Americans and Caucasians in colon cancer adjuvant therapy trials: findings from the National Surgical Adjuvant Breast and Bowel Project

BACKGROUND

African-Americans generally have lower survival rates from colon cancer than Caucasian Americans. This disparity has been attributed to many sources, including diagnosis at later disease stage and other unfavorable disease features, inadequate treatment, and socioeconomic factors. The randomized clinical trial setting ensures similarity in disease stage and a uniform treatment plan between blacks and whites. In this study, we evaluated survival and related end points for African-American and Caucasian patients with colon cancer participating in randomized clinical trials of the National Surgical Adjuvant Breast and Bowel Project (NSABP) to determine whether outcomes were less favorable for African-Americans.

METHODS

The study included African-American (n = 663) or Caucasian (n = 5969) patients from five serially conducted, randomized clinical trials of the NSABP. We compared recurrence-free survival, disease-free survival (recurrence, new primary cancer, or death), and survival (death from any cause) between blacks and whites by using statistical modeling to account for differences in patient and disease characteristics between the groups. Statistical tests were two-sided.

RESULTS

Dukes' stage and number of positive lymph nodes were remarkably similar between African-American and Caucasian patients in each trial. Over all trials combined, an 8% (95% confidence interval [CI] = -6% to 25%; P =.27) excess risk of colon cancer recurrence that was not statistically significant was observed for blacks. A greater disparity in survival was seen, with blacks experiencing a statistically significant 21% (95% CI = 6%-37%; P =.004) greater risk of death. Treatment efficacy appeared similar between the groups.

CONCLUSIONS

While the overall survival prognosis was less favorable for African-Americans compared with Caucasians in these trials, other outcomes measured were considerably more similar than those seen in the population at large, suggesting that earlier detection and adjuvant therapy could appreciably improve colon cancer prognosis for African-Americans. Continued investigations into causes of the deficits noted are warranted.