Racial Disparities in Cancer Presentation and Outcomes: The Contribution of Overdiagnosis

Incidence of papillary thyroid cancer: Comparison of the military and the general population by race and tumor stage/size

BACKGROUND

A previous study found higher papillary thyroid cancer incidence in the US military than the general population with larger differences among Black than White individuals. This study compared the two populations in the incidence by sex, race, tumor stage, and size to assess possible factors related to identified differences.

METHODS

Subjects were aged 18-59 in the military and general populations. Papillary thyroid cancer patients diagnosed during 1990-2013 were identified from the Department of Defense's Automated Central Tumor Registry (ACTUR) and the National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) program. Age-adjusted rates and incidence rate ratios (IRR) comparing ACTUR to SEER were calculated.

RESULTS

Higher incidence rates in ACTUR than SEER were more obvious for Black (IRR=2.07, 95%CI=1.56-2.70) than White men (IRR=1.17, 95%CI=1.07-1.26) and for Black (IRR=2.30, 95%CI=1.91-2.71) than White women (IRR=1.50, 95%CI=1.38-1.64). Population differences by race were observed for localized tumors among both men and women and were larger for Black individuals. Differences were observed regardless of tumor size among Black men and White women, and in smaller tumors among Black women.

CONCLUSION

Higher incidence in the military than general population primarily in localized tumors suggests universal healthcare in the military may lead to earlier detection. The differences were larger among Blacks than Whites, suggesting universal access in the military may be more impactful among Black persons, who are less likely to have timely care than White persons in the general population. Nevertheless, observed differences for tumors > 2 cm suggest other factors may also play a role.

Racial/ethnic disparities in thyroid cancer in California, 1999-2017

BACKGROUND

Recent studies examining treatment disparities in thyroid cancer care found that appropriate use of surgery and radioactive iodine may be improving over time.

METHODS

California Cancer Registry and California Office of Statewide Health Planning and Development data was evaluated for the effect of race on overall and disease-specific survival for thyroid cancer in California (1999-2017). Reoperation data was also examined. We hypothesized treatment and outcome disparities would persist between Black and white patients.

RESULTS

Black patients with thyroid cancer had worse overall survival than white patients (p < 0.01). No difference was found in disease-specific survival between Black and white patients after adjusting for SES and health insurance status. Black patients underwent reoperation less frequently (1.4%) (HR = 0.70 [CI, 0.50-0.99], p < 0.05) than white patients (2.0%).

CONCLUSIONS

SES and insurance type are drivers of disparities in thyroid cancer survival in Black patients. Addressing social determinants of health or healthcare access are paramount to addressing disparities in thyroid cancer between Black and white patients.

COVID-19 in people with neurofibromatosis 1, neurofibromatosis 2, or schwannomatosis

PURPOSE

People with pre-existing conditions may be more susceptible to severe COVID-19 when infected by SARS-CoV-2. The relative risk and severity of SARS-CoV-2 infection in people with rare diseases such as neurofibromatosis type 1 (NF1), neurofibromatosis type 2 (NF2), or schwannomatosis (SWN) is unknown.

METHODS

We investigated the proportions of people with NF1, NF2, or SWN in the National COVID Cohort Collaborative (N3C) electronic health record data set who had a positive test result for SARS-CoV-2 or COVID-19.

RESULTS

The cohort sizes in N3C were 2501 (NF1), 665 (NF2), and 762 (SWN). We compared these with N3C cohorts of patients with other rare diseases (98-9844 individuals) and the general non-NF population of 5.6 million. The site- and age-adjusted proportion of people with NF1, NF2, or SWN who had a positive test result for SARS-CoV-2 or COVID-19 (collectively termed positive cases) was not significantly higher than in individuals without NF or other selected rare diseases. There were no severe outcomes reported in the NF2 or SWN cohorts. The proportion of patients experiencing severe outcomes was no greater for people with NF1 than in cohorts with other rare diseases or the general population.

CONCLUSION

Having NF1, NF2, or SWN does not appear to increase the risk of being SARS-CoV-2 positive or of being a patient with COVID-19 or of developing severe complications from SARS-CoV-2.

Relative Survival With Early-Stage Breast Cancer in Screened and Unscreened Populations

Relative survival and disease-specific survival are two statistics that measure net survival from a cancer diagnosis, excluding other causes of death. In most cases, these two rates are comparable. However, in some cancer types for which cancer screening is performed, relative survival is often greater than disease-specific survival. This divergence has been attributed to mechanisms such as the "healthy user effect" and overdiagnosis of indolent tumors detected by screening. Using relative survival rate as a marker of these mechanisms, we examined the association of breast cancer screening with relative survival rates for women diagnosed with early-stage breast cancer. In population-based data from the National Cancer Institute's Surveillance, Epidemiology and End Results registry, we examined relative survival rates in women diagnosed with stage I breast cancer or ductal carcinoma in situ who were in highly screened vs less-highly screened groups, based on time period, age group, and insurance status. In this analysis, relative survival rates for early-stage breast cancer were higher than disease-specific survival, even exceeding 100% in populations experiencing higher rates of screening (ie, women diagnosed during the era of widespread uptake of mammography, age older than 40 years, and women with health insurance coverage). The favorable outcomes observed in screen-detected breast cancers are at least in part attributable to the healthy user effect and overdiagnosis of indolent tumors. Therefore, survival rates may not accurately reflect the effectiveness of cancer screening. These findings have implications for counseling of patients and future clinical studies of active monitoring approaches in breast cancer.

Disparities in the impact of the AJCC 8th edition staging system on differentiated thyroid cancer outcomes

BACKGROUND

The impact of AJCC8 among self-reported racial/ethnic groups on differentiated thyroid cancer (DTC) outcomes is unknown.

METHODS

Multivariate-regression evaluated the association between AJCC7 to AJCC8 stage change and race/ethnicity in patients with DTC in the NCDB. Cox-proportional-regression evaluated whether AJCC7 to AJCC8 stage change affects overall survival (OS) differently based on reported race/ethnicity.

RESULTS

After adjusting for confounders, Hispanics and Asian-Pacific-Islanders (APIs) were 27% and 12% less likely to be down-staged compared to white-non-Hispanics (WNHs) (p < 0.001); black-non-Hispanics (BNHs) had no significant down-staging difference. Down-staged patients had an increased risk of death compared to patients with unchanged staging, regardless of race/ethnicity. However, based on two-way interaction, the magnitude of this negative change on survival from down-staging was only different between WNHs (HR = 2.64) and BNHs (HR = 1.77), (p = 0.04).

CONCLUSIONS

Outcome disparities persist among self-reported racial/ethnic groups with AJCC8. Down-staged patients across all racial/ethnic groups had decreased survival compared to those with unchanged stage, with the least impact in BNHs.

Disparities in Thyroid Care

Thyroid disease affects an estimated 20 million Americans, with 1 in 8 women developing a thyroid disorder during her lifetime. Although most patients with thyroid cancer have a good prognosis and effective treatments for benign thyroid disease are available, disparities exist in thyroid care and result in worse outcomes for racial and ethnic minorities. Inequities in the diagnosis and treatment of thyroid disease are due to the complex interplay of systems-, physician-, and patient-level factors. Thus, innovative strategies that take an ecological approach to addressing racial disparities are needed to achieve equitable care for all patients with thyroid disease.

Persistence of Disparity in Thyroid Cancer Survival After Adjustments for Socioeconomic Status and Access

INTRODUCTION

Thyroid cancer incidence has increased substantially in the past 4 decades, estimated at 3.5% annually. Incidence is highest in white patients, yet black patients have the worst survival. Racial/ethnic differences in presentation and outcomes are hypothesized to be a result of differences in access to care. Analyses delineating the relative contribution of access to racial/ethnic survival disparities are scarce. We aimed to explore the association of delay in access to care and early/increased detection with racial/ethnic disparities in thyroid cancer survival.

METHODS

The Surveillance, Epidemiology, and End Results (SEER) database was queried from 2007 to 2011 for patients with a first primary thyroid cancer diagnosis and up to 5 years of follow-up. Composite scores were generated from county-level variables to capture socioeconomic status and screening habits. Kaplan-Meier analysis and Cox proportional hazards models were utilized for survival analysis.

RESULTS

We identified 46,970 patients (67% white, 7% black, 15% Hispanic, 10% Asian or Pacific Islander, and 1% unknown/other). Compared to white patients, black, Hispanic, and Asian or Pacific Islander patients were more likely to present with distant disease (3% vs 5%, 5%, and 6%, respectively; P < .001). After adjusting for sex, age, stage, subtype, tumor size, surgery, radiation, socioeconomics, and screening habits, black patients were the only race/ethnicity found to have increased odds of 5-year mortality compared to white patients (24%, P < .001).

CONCLUSION

Thyroid cancer survival is worst for black patients regardless of socioeconomic status or screening habits. Racial/ethnic disparities in survival are not attributable to early detection alone.

Sinonasal adenocarcinoma: Population-based analysis of demographic and socioeconomic disparities

BACKGROUND

Sinonasal adenocarcinoma (SNAC) is a rare tumor. The impact of health disparities on survival, stage at presentation, and utilization of surgery is not well understood in patients with SNAC.

METHODS

The Surveillance, Epidemiology, and End Results database was queried for cases of SNAC from 1973 to 2015. Cases were analyzed to assess for disparities in presentation, treatment, and survival.

RESULTS

SNAC was identified in 630 patients. In a multivariate model of overall survival, an age increase of 10 years (Hazard Ratio (HR) = 1.37, p < 0.001), male sex (HR = 1.26, p = 0.045), and more recent decade of diagnosis (HR = 0.74, p < 0.001) were significantly related to time-to-death. There is a higher rate of SNAC-related death in counties with more rural populations (p = 0.027).

CONCLUSION

Future interventions targeting rural and less well-educated populations may improve care with the goal of increasing the span of healthy life and reducing survival disparities related to SNAC.

Function-related Indicators and Outcomes of Screening Mammography in Older Women: Evidence from the Breast Cancer Surveillance Consortium Cohort

BACKGROUND

Previous reports suggested risk of death and breast cancer varied by comorbidity and age in older women undergoing mammography. However, impacts of functional limitations remain unclear.

METHODS

We used data from 238,849 women in the Breast Cancer Surveillance Consortium-Medicare linked database (1999-2015) who had screening mammogram at ages 66-94 years. We estimated risk of breast cancer, breast cancer death, and non-breast cancer death by function-related indicator (FRI) which incorporated 16 claims-based items and was categorized as an ordinal variable (0, 1, and 2+). Fine and Gray proportional sub-distribution hazards models were applied with breast cancer and death treated as competing events. Risk estimates by FRI scores were adjusted by age and NCI comorbidity index separately and stratified by these factors.

RESULTS

Overall, 9,252 women were diagnosed with breast cancer, 406 died of breast cancer, and 41,640 died from non-breast cancer causes. The 10-year age-adjusted invasive breast cancer risk slightly decreased with FRI score [FRI = 0: 4.0%, 95% confidence interval (CI) = 3.8-4.1; FRI = 1: 3.9%, 95% CI = 3.7-4.2; FRI ≥ 2: 3.5%, 95% CI = 3.1-3.9). Risk of non-breast cancer death increased with FRI score (FRI = 0: 18.8%, 95% CI = 18.5-19.1; FRI = 1: 24.4%, 95% CI = 23.9-25.0; FRI ≥ 2: 39.8%, 95% CI = 38.8-40.9]. Risk of breast cancer death was low with minimal differences across FRI scores. NCI comorbidity index-adjusted models and stratified analyses yielded similar patterns.

CONCLUSIONS

Risk of non-breast cancer death substantially increases with FRI score, whereas risk of breast cancer death is low regardless of functional status.

IMPACT

Older women with functional limitations should be informed that they may not benefit from screening mammography.

Early Diagnosis of Low-Risk Papillary Thyroid Cancer Results Rather in Overtreatment Than a Better Survival

We are witnessing a rapid worldwide increase in the incidence of papillary thyroid carcinoma (PTC) in the last thirty years. Extensive implementation of cancer screening and wide availability of neck ultrasound or other imaging studies is the main reason responsible for this phenomenon. It resulted in a detection of a growing number of clinically asymptomatic PTCs, mainly low-risk tumors, without any beneficial impact on survival. An indolent nature of low-risk PTC, particularly papillary thyroid microcarcinoma (PTMC), and the excellent outcomes raise an ongoing discussion regarding the adequacy of treatment applied. The question of whether PTMC is overtreated or not is currently completed by another, whether PTMC requires any treatment. Current ATA guidelines propose less extensive preoperative diagnostics and, if differentiated thyroid cancer is diagnosed, less aggressive surgical approach and limit indications for postoperative radioiodine therapy. However, in intrathyroidal PTMCs in the absence of lymph node or distant metastases, active surveillance may constitute alternative management with a low progression rate of 1%-5% and without any increase in the risk of poorer outcomes related to delayed surgery in patients, in whom it was necessary. This review summarizes the current knowledge and future perspectives of active surveillance in low-risk PTC.