Christopher J. Johnson

Methods for improving cancer surveillance data in American Indian and Alaska Native populations.

The misclassification of race decreases the accuracy of cancer incidence data for American Indians and Alaska Natives (AI/ANs) in some central cancer registries. This article describes the data sources and methods that were used to address this misclassification and to produce the cancer statistics used by most of the articles in this supplement.

Breast cancer stage at diagnosis: is travel time important?

Recent studies have produced inconsistent results in their examination of the potential association between proximity to healthcare or mammography facilities and breast cancer stage at diagnosis. Using a multistate dataset, we re-examine this issue by investigating whether travel time to a patient’s diagnosing facility or nearest mammography facility impacts breast cancer stage at diagnosis. We studied 161,619 women 40xa0years and older diagnosed with invasive breast cancer from ten state population based cancer registries in the United States. For each woman, we calculated travel time to their diagnosing facility and nearest mammography facility. Logistic multilevel models of late versus early stage were fitted, and odds ratios were calculated for travel times, controlling for age, race/ethnicity, census tract poverty, rural/urban residence, health insurance, and state random effects. Seventy-six percent of women in the study lived less than 20xa0minxa0from their diagnosing facility, and 93 percent lived less than 20xa0min from the nearest mammography facility. Late stage at diagnosis was not associated with increasing travel time to diagnosing facility or nearest mammography facility. Diagnosis age under 50, Hispanic and Non-Hispanic Black race/ethnicity, high census tract poverty, and no health insurance were all significantly associated with late stage at diagnosis. Travel time to diagnosing facility or nearest mammography facility was not a determinant of late stage of breast cancer at diagnosis, and better geographic proximity did not assure more favorable stage distributions. Other factors beyond geographic proximity that can affect access should be evaluated more closely, including facility capacity, insurance acceptance, public transportation, and travel costs.

Improving Cancer Incidence Estimates for American Indians and Alaska Natives in the Pacific Northwest

In many disease registries, including cancer registries, misclassification of American Indian and Alaska Native (AI/AN) race is common. This type of misclassification threatens the validity of existing estimates of disease occurrence in this population.1–9 From a public health perspective, the underestimation of cancer incidence has a potentially great effect, as appropriate cancer control measures are less likely to be implemented in light of spuriously low rates. The problem of racial misclassification of AI/AN race in cancer registries appears to be widespread: investigators in several states have shown that AI/AN race is frequently underreported in both federally sponsored and state-supported cancer registries.4–8 n nWe conducted record linkage studies to evaluate the extent of racial misclassification of AI/ANs in the cancer registries for Idaho, Oregon, and Washington states that constitute the administrative unit of the Indian Health Service (IHS) known as the Portland Area IHS. We also calculated estimates of cancer incidence among AI/ANs in these states.

Geographic proximity to treatment for early stage breast cancer and likelihood of mastectomy

PURPOSEnWomen with early stage breast cancer who live far from a radiation therapy facility may be more likely to opt for mastectomy over breast conserving surgery (BCS). The geographic dimensions of this relationship deserve further scrutiny.nnnMETHODSnFor over 100,000 breast cancer patients in 10 states who received either mastectomy or BCS, a newly-developed software tool was used to calculate the shortest travel distance to the location of surgery and to the nearest radiation treatment center. The likelihood of receipt of mastectomy was modeled as a function of these distance measures and other demographic variables using multilevel logistic regression.nnnRESULTSnWomen traveling over 75xa0km for treatment are about 1.4 times more likely to receive a mastectomy than those traveling under 15xa0km.nnnCONCLUSIONSnGeographic barriers to optimal breast cancer treatment remain a valid concern, though most women traveling long distances to receive mastectomies are doing so after bypassing local options.

The Relationship Between Area Poverty Rate and Site-Specific Cancer Incidence in the United States

The relationship between socioeconomic status and cancer incidence in the United States has not traditionally been a focus of population‐based cancer surveillance systems.

Association between cutaneous melanoma incidence rates among white US residents and county-level estimates of solar ultraviolet exposure

BACKGROUNDnRecent US studies have raised questions as to whether geographic differences in cutaneous melanoma incidence rates are associated with differences in solar ultraviolet (UV) exposure.nnnOBJECTIVESnWe sought to assess the association of solar UV exposure with melanoma incidence rates among US non-Hispanic whites.nnnMETHODSnWe assessed the association between county-level estimates of average annual solar UV exposure for 1961 to 1990 and county-level melanoma incidence rates during 2004 to 2006. We used Poisson multilevel mixed models to calculate incidence density ratios by cancer stage at diagnosis while controlling for individuals age and sex and for county-level estimates of solar UV exposure, socioeconomic status, and physician density.nnnRESULTSnAge-adjusted rates of early- and late-stage melanoma were both significantly higher in high solar UV counties than in low solar UV counties. Rates of late-stage melanoma incidence were generally higher among men, but younger women had a higher rate of early-stage melanoma than their male counterparts. Adjusted rates of early-stage melanoma were significantly higher in high solar UV exposure counties among men aged 35 years or older and women aged 65 years or older.nnnLIMITATIONSnThe relationship between individual-level UV exposure and risk for melanoma was not evaluated.nnnCONCLUSIONSnCounty-level solar UV exposure was associated with the incidence of early-stage melanoma among older US adults but not among younger US adults. Additional studies are needed to determine whether exposure to artificial sources of UV exposure or other factors might be mitigating the relationship between solar UV exposure and risk for melanoma.

Associations of Census-Tract Poverty with Subsite-Specific Colorectal Cancer Incidence Rates and Stage of Disease at Diagnosis in the United States

Background. It remains unclear whether neighborhood poverty contributes to differences in subsite-specific colorectal cancer (CRC) incidence. We examined associations between census-tract poverty and CRC incidence and stage by anatomic subsite and race/ethnicity. Methods. CRC cases diagnosed between 2005 and 2009 from 15 states and Los Angeles County (N = 278,097) were assigned to 1 of 4 groups based on census-tract poverty. Age-adjusted and stage-specific CRC incidence rates (IRs) and incidence rate ratios (IRRs) were calculated. Analyses were stratified by subsite (proximal, distal, and rectum), sex, race/ethnicity, and poverty. Results. Compared to the lowest poverty areas, CRC IRs were significantly higher in the most impoverished areas for men (IRR = 1.14 95% CI 1.12–1.17) and women (IRR = 1.06 95% CI 1.05–1.08). Rate differences between high and low poverty were strongest for distal colon (male IRR = 1.24 95% CI 1.20–1.28; female IRR = 1.14 95% CI 1.10–1.18) and weakest for proximal colon. These rate differences were significant for non-Hispanic whites and blacks and for Asian/Pacific Islander men. Inverse associations between poverty and IRs of all CRC and proximal colon were found for Hispanics. Late-to-early stage CRC IRRs increased monotonically with increasing poverty for all race/ethnicity groups. Conclusion. There are differences in subsite-specific CRC incidence by poverty, but associations were moderated by race/ethnicity.

Examining the challenges of family recruitment to behavioral intervention trials: factors associated with participation and enrollment in a multi-state colonoscopy intervention trial

BackgroundColonoscopy is one of the most effective methods of cancer prevention and detection, particularly for individuals with familial risk. Recruitment of family members to behavioral intervention trials remains uniquely challenging, owing to the intensive process required to identify and contact them. Recruiting at-risk family members involves contacting the original cancer cases and asking them to provide information about their at-risk relatives, who must then be contacted for study enrollment. Though this recruitment strategy is common in family trials, few studies have compared influences of patient and relative participation to nonparticipation. Furthermore, although use of cancer registries to identify initial cases has increased, to our knowledge no study has examined the relationship between registries and family recruitment outcomes.MethodsThis study assessed predictors of case participation and relative enrollment in a recruitment process that utilized state cancer registries. Participation characteristics were analyzed with separate multivariable logistic regressions in three stages: (1) cancer registry-contacted colorectal cancer (CRC) cases who agreed to study contact; (2) study-contacted CRC cases who provided at-risk relative information; and (3) at-risk relatives contacted for intervention participation.ResultsCancer registry source was predictive of participation for both CRC cases and relatives, though relative associations (odds ratios) varied across registries. Cases were less likely to participate if they were Hispanic or nonwhite, and were more likely to participate if they were female or younger than 50 at cancer diagnosis. At-risk relatives were more likely to participate if they were from Utah, if another family member was also participating in the study, or if they had previously had a colonoscopy. The number of eligible cases who had to be contacted to enroll one eligible relative varied widely by registry, from 7 to 81.ConclusionsFamily recruitment utilizing cancer registry-identified cancer cases is feasible, but highly dependent on both the strategies and protocols of those who are recruiting and on participant characteristics such as sex, race, or geography. Devising comprehensive recruitment protocols that specifically target those less likely to enroll may help future research meet recruitment goals.Trial registrationFamily Colorectal Cancer Awareness and Risk Education Project NCT01274143.

The relationship between cancer incidence, stage and poverty in the United States

We extend a prior analysis on the relation between poverty and cancer incidence in a sample of 2.90 million cancers diagnosed in 16 US states plus Los Angeles over the 2005–2009 period by additionally considering stage at diagnosis. Recognizing that higher relative disparities are often found among less‐common cancer sites, our analysis incorporated both relative and absolute measures of disparities. Fourteen of the 21 cancer sites analyzed were found to have significant variation by stage; in each instance, diagnosis at distant stage was more likely among residents of high‐poverty areas. If the incidence rates found in the lowest‐poverty areas for these 21 cancer sites were applied to the entire country, 18,000 fewer distant‐stage diagnoses per year would be expected, a reduction of 8%. Conversely, 49,000 additional local‐stage diagnoses per year would be expected, an increase of 4%. These figures, strongly influenced by the most common sites of prostate and female breast, speak to the trade‐offs inherent in cancer screening. Integrating the type of analysis presented here into routine cancer surveillance activities would permit a more complete understanding of the dynamic nature of the relationship between socioeconomic status and cancer incidence.