Predictors of advanced stage colorectal cancer diagnosis: results of a population-based study.

While colon cancer is a leading cause of morbidity and mortality among men and women, little is known about demographic variables associated with advanced stage diagnosis at diagnosis. We examined the relationship of age, gender, income, education, marital status, smoking status, urban versus rural residence, and proximal versus distal tumor location on stage at diagnosis. Data from Florida statewide cancer registry for the year 1994 with over 8,933 cases of colorectal cancer was analyzed. Using multivariate analysis, an odds ratio of being diagnosed with advanced stage disease was determined for each demographic variable. We found a significantly increased probability (P < .05) of diagnosis with advanced stage disease for distal lesions in middle-aged persons, smokers, and those with higher education or lower income status. If these findings are verified, they may suggest a group that warrants targeted screening intervention or programs over and above today's current colorectal screening recommendations.

Comorbid illness and the early detection of cancer.

BACKGROUND: Comorbidity may be associated with later detection of cancer. METHODS: Incident cases of colorectal, breast, and prostate cancer and melanoma were determined from the 1994 Florida state tumor registry (N = 32,074). The relationship between comorbidity and late stage at diagnosis was examined using multiple logistic regression. RESULTS: Patients with comorbid conditions had greater odds of late stage diagnosis for each of the four cancers (colorectal, melanoma, breast, and prostate). Higher mortality rates were observed among patients with comorbid illness, not as a result of later stage at diagnosis, but rather due to their underlying disease. CONCLUSIONS: Comorbidity was associated with later stage diagnosis. Further research is needed to determine mechanisms by which comorbidity might influence stage at diagnosis.

Predictors of proximal vs. distal colorectal cancers.

BACKGROUND: Because proximal colorectal cancers have a tendency to present at a more advanced stage and thus have a poorer prognosis, it is important to understand the factors associated with the development of proximal colorectal cancer. We hypothesized that older age, female gender, and the presence of comorbid illness would be associated with proximal cancers. METHODS: Incident cases of colorectal cancer (n = 9,550) occurring in 1994 were identified from Florida's population-based statewide cancer registry. We categorized colorectal cancers as either proximal (cecum, ascending colon, and transverse colon) or distal (descending colon, sigmoid colon, rectosigmoid, and rectum). Multiple logistic regression analysis was used to determine the multivariable relationship between clinical characteristics and the odds of a proximal-occurring lesion. RESULTS: Four characteristics emerged as independent predictors of a proximal lesion. Each year of increasing age was associated with a 2.2 percent increase in the odds of a proximal lesion, whereas female gender was associated with a 38 percent increase in the odds of a proximal lesion. The presence of a comorbid condition was associated with a 28 percent greater odds of a proximal lesion, and, finally, black, non-Hispanic race was associated with a 24 percent greater odds of a proximal lesion. CONCLUSIONS: We found that increasing age, female gender, black, non-Hispanic race, and the presence of comorbid illnesses were factors associated with a greater likelihood of developing colorectal cancer in a proximal location. Further studies will be required to confirm these findings and to establish the mechanism by which comorbidity influences the site of colorectal cancer development.

Effects of physician supply on early detection of breast cancer.

BACKGROUND: There are few studies examining the effects of physician supply on health-related outcomes. We hypothesized that increasing physician supply and, in particular, increasing primary care supply would be related to earlier detection of breast cancer. METHODS: Information on incident cases of breast cancer occurring in Florida in 1994 (n = 11,740) was collected from the state cancer registry. Measures of physician supply were obtained from the 1994 AMA Physician Masterfile. The effects of physician supply on the odds of late-stage diagnosis were examined using multiple logistic regression. RESULTS: There was no relation between overall physician supply and stage of breast cancer of diagnosis. Each 10th percentile increase in primary care physician supply, however, resulted in a 4% increase in the odds of early-stage diagnosis (adjusted odds ratio = 1.04, 95% confidence interval = 1.01-1.06). CONCLUSIONS: The supply of primary care physicians was significantly associated with earlier stage of breast cancer at diagnosis. This study suggests that an appropriate balance of primary care and specialty physician supply might be an important predictor of health outcomes.

Effects of health insurance and race on colorectal cancer treatments and outcomes.

OBJECTIVES: We hypothesized that health insurance payer and race might influence the care and outcomes of patients with colorectal cancer. METHODS: We examined treatments received for all incident cases of colorectal cancer occurring in Florida in 1994 (n = 9551), using state tumor registry data. We also estimated the adjusted risk of death (through 1997), using proportional hazards regression analysis controlling for other predictors of mortality. RESULTS: Treatments received by patients varied considerably according to their insurance payer. Among non-Medicare patients, those in the following groups had higher adjusted risks of death relative to commercial fee-for-service insurance: commercial HMO (risk ratio [RR] = 1.40; 95% confidence interval [CI] = 1.18, 1.67; P = .0001), Medicaid (RR = 1.44; 95% CI = 1.06, 1.97; P = .02), and uninsured (RR = 1.41; 95% CI = 1.12, 1.77; P = .003). Non-Hispanic African Americans had higher mortality rates (RR = 1.18; 95% CI = 1.01, 1.37; P = .04) than non-Hispanic Whites. CONCLUSIONS: Patients with colorectal cancer who were uninsured or insured by Medicaid or commercial HMOs had higher mortality rates than patients with commercial fee-for-service insurance. Mortality was also higher among non-Hispanic African American patients.

Increasing supplies of dermatologists and family physicians are associated with earlier stage of melanoma detection.

BACKGROUND: Physicians are important in the early detection of melanoma. We investigated whether primary care physician supply and the supply of dermatologists were related to stage at diagnosis for malignant melanoma. METHODS: From the state tumor registry in Florida in 1994, we identified incident cases of malignant melanoma for which stage at diagnosis was available (N = 1884). Data on physician supply was obtained from the 1994 American Medical Association Physician Masterfile. Logistic regression determined the effects of physician supply (at the ZIP code level) on the odds of early-stage diagnosis controlling for patients' age, gender, race/ethnicity, marital status, education level, income level, comorbidity, and type of health insurance. RESULTS: Each additional dermatologist per 10,000 population was associated with a 39% increased odds of early diagnosis (odds ratio = 1.39, 95% confidence interval [CI] 1.09-1.70, P =.010). For each additional family physician per 10,000 population, the odds of early diagnosis increased 21% (odds ratio = 1.21, 95% CI 1.09-1.33, P <.001). Each additional general internist per 10,000 population was associated with a 10% decrease in the odds of early-stage diagnosis (odds ratio = 0.90, 95% CI 0.83-0.98, P =.009). The supplies of general practitioners, obstetrician/gynecologists, and other nonprimary care specialists were not associated with stage at diagnosis. CONCLUSIONS: Increasing supplies of dermatologists and family physicians were associated with earlier detection of melanoma. In contrast, increasing supplies of general internists were associated with reduced odds of early detection. Our findings suggest that the composition of the physician work force may affect important health outcomes and needs further study.

Demographic predictors of melanoma stage at diagnosis.

OBJECTIVE: To examine sociodemographic characteristics as possible predictors of late-stage melanoma diagnosis. We hypothesized that late-stage diagnosis would be associated with the following: older age, male sex, unmarried status, lower educational attainment and income level, rural residence, and cigarette smoking. METHODS: We used data from the state tumor registry to study all incident cases of melanoma occurring in Florida during 1994 whose stage at diagnosis was available (N = 1884). We used multiple logistic regression to determine the effects of sociodemographic characteristics on the odds of late-stage (regional or distant metastases) diagnosis. RESULTS: There were 243 patients (12.9%) diagnosed as having melanoma that had metastasized to either regional lymph nodes or distant sites. Patients who were unmarried (odds ratio, 1.5; P= .01), male (odds ratio, 2.2; P<.001), or smokers (odds ratio, 2.2; P<.001) or who resided in communities with lower median educational attainment (odds ratio, 1.5; P= .048) had greater odds of having a late-stage diagnosis. CONCLUSIONS: To detect these cancers at an earlier stage and improve outcomes, there should be increased educational efforts directed toward physicians who treat these patients. A recognition that there may be additional risk factors for late-stage diagnosis, beyond the established risk factors, such as family history and excess sun exposure, should be included in the initial assessment. Specific public education efforts should also be targeted to these patients to increase their self-surveillance and surveillance of their partners.

Clinical and demographic predictors of late-stage cervical cancer.

BACKGROUND: Despite increasingly widespread use of the Papanicolaou smear, almost half of all women with invasive cervical cancer are diagnosed at a late stage (regional or distant). Little is known about factors associated with late-stage diagnosis of cervical cancer. OBJECTIVE: To examine the relationship of age, race, education level, income level, smoking, marital status, health insurance type, comorbidity, and residence in an urban or rural setting to late stage at diagnosis of cervical cancer. METHODS: Incident cases of invasive cervical cancer occurring in 1994 in Florida were identified from the state tumor registry (N = 852). Cases were linked with state discharge abstracts and the 1990 US census. Multiple logistic regression was used to determine the relationship between predictor variables (age, race or ethnicity, marital status, smoking status, education level, income level, insurance type, comorbidity, and urban vs rural residence) and the odds of late-stage diagnosis. RESULTS: Age, marital status, and insurance type were associated with late-stage diagnosis. Each additional year of age was associated with a 3% increased odds of late-stage diagnosis (odds ratio [OR], 1.03; 95% confidence interval [CI], 1.02-1.05; P<.001). Being unmarried was associated with a 63% increased odds of late-stage diagnosis (OR, 1.63; 95% CI, 1.18-2.25; P=.003). Being uninsured was associated with a 60% increased odds of late-stage diagnosis (OR, 1.60; 95% CI, 1.07-2.38; P=.02). Having commercial health maintenance organization insurance was associated with a 46% decreased odds of late-stage disease (OR, 0.54; 95% CI, 0.30-0.96; P=.04). Race, education level, income level, smoking status, comorbidity, and urban residence were not associated with stage at diagnosis. CONCLUSIONS: Women with cervical cancer who are elderly, unmarried, and uninsured are more likely to be diagnosed at a late stage. These women should be targeted for cervical cancer education and screening programs.

Effects of health insurance and race on breast carcinoma treatments and outcomes.

BACKGROUND: The authors hypothesized that insurance payer and race would influence the care and outcomes for patients with breast carcinoma. METHODS: The authors examined treatments and adjusted risk of death (through 1997) for all incident cases of breast carcinoma occurring in Florida in 1994 (n = 11,113) by using state tumor registry data. RESULTS: Patients lacking health insurance were less likely to receive breast-conserving surgery (BCS) compared with patients who had private health insurance. Among patients insured by Medicare, those belonging to a health maintenance organization (HMO) were more likely to receive BCS but less likely to receive radiation therapy after BCS. Non-Hispanic African Americans had higher mortality rates even when stage at diagnosis, insurance payer, and treatment modalities used were adjusted in multivariate models (adjusted risk ratio [RR], 1.35; 95% confidence interval [CI], 1.12-1.61; P = 0.001). Patients who had HMO insurance had similar survival rates compared with those with fee-for-service (FFS) insurance. Among non-Medicare patients, mortality rates were higher for patients who had Medicaid insurance (RR, 1.58, 95% CI, 1.18-2.11; P = 0.002) and those who lacked health insurance (RR, 1.31; 95% CI, 1.03-1.68; P = 0.03) compared with patients who had commercial FFS insurance. There were no insurance-related differences in survival rates, however, once stage at diagnosis was controlled. CONCLUSIONS: As a result of later stage at diagnosis, patients with breast carcinoma who were uninsured, or insured by Medicaid, had higher mortality rates. Mortality rates were also higher among non-Hispanic African Americans, a finding that was not fully explained by differences in stage at diagnosis, treatment modalities used, or insurance payer.

The effects of physician supply on the early detection of colorectal cancer.

BACKGROUND: Policymakers question whether there is a relationship between the number and distribution of physicians and the outcomes for important health conditions. We hypothesized that increasing primary care physician supply would be related to earlier detection of colorectal cancer. METHODS: We identified incident cases of colorectal cancer occurring in Florida in 1994 (n = 8,933) from the state cancer registry. We then obtained measures of physician supply from the 1994 American Medical Association Physician Masterfile and examined the effects of physician supply (at the levels of county and ZIP code clusters) on the odds of late-stage diagnosis using multiple logistic regression. RESULTS: For each 10-percentile increase in primary care physician supply at the county level, the odds of late-stage diagnosis decreased by 5% (adjusted odds ratio [OR] = 0.95; 95% confidence interval [CI], 0.92 - 0.99; P = .007). For each 10-percentile increase in specialty physician supply, the odds of late-stage diagnosis increased by 5% (adjusted OR = 1.05; 95% CI, 1.02-1.09; P = .006). Within ZIP code clusters, each 10-percentile increase in the supply of general internists was associated with a 3% decrease in the odds of late-stage diagnosis (OR = 0.97; 95% CI, 0.95 - 0.99; P = .006), and among women, each 10-percentile increase in the supply of obstetrician/gynecologists was associated with a 5% increase in the odds of late-stage diagnosis (OR = 1.05; 95% CI, 1.01 - 1.08; P = .005). CONCLUSIONS: If the relationships observed were causal, then as many as 874 of the 5463 (16%) late-stage colorectal cancer diagnoses are attributable to the physician specialty supply found in Florida. These findings suggest that an appropriate balance of primary care and specialty physicians may be important in achieving optimal health outcomes.

Colorectal cancer screening.

The decision whether to launch a screening program in asymptomatic patients of average risk for colorectal cancer and the selection of the appropriate protocol for screening are complex issues. There are still many unanswered questions. Many organizations such as the American Cancer Society, the World Health Organization Collaborating Center for the Prevention of Colorectal Cancer, and the U.S. National Cancer Institute advocate screening with annual Hemoccult tests and screening with flexible sigmoidoscopy every 3 to 5 years in patients more than 50 years of age. The U.S. Preventive Services Task Force, the Canadian Task Force on Periodic Health Examination, and the International Union Against Cancer have not recommended screening asymptomatic average-risk patients for colorectal cancer. One study showed a small but significant benefit (3 per 1000) of the rehydrated annual Hemoccult test in reducing mortality from colorectal cancer. To embark on a mass screening strategy as recommended, however, would require significant costs, increases in physician training, improved access to the requisite technology, and enhancements in patient and physician compliance. Furthermore, the high false-positive rates of the rehydrated Hemoccult tests would lead to many unnecessary tests, causing greater expense as well as patient discomfort and anxiety. It is, therefore, premature to recommend mass screening for colorectal cancer in asymptomatic individuals at this time. Further research is needed to identify risk factors (such as genetic markers) better and to develop and evaluate screening strategies targeted at those with high risk for colorectal cancer. In the meantime, efforts at primary prevention for the general population should be increased (through nutrition and exercise). Patients over the age of 50 who desire screening should be given information of the benefits and risks of screening and together with their physicians decide on a screening strategy that suits their needs and values.