Cancer Mortality Patterns by Birthplace and Generation Status of Mexican Latinos: The Multiethnic Cohort

Gendered interpretations of the causes of breast cancer: a structured review of migrant studies

BACKGROUND

Breast cancer is the most prevalent cancer in women worldwide. Despite it having an etiology that has fixed, genetic as well as modifiable, environmental risk factors, the narrative around breast cancer prevention emphasizes gendered interpretations of the etiology, such as "reproductive factors cause breast cancer" and women should change their behaviors to reduce their risk. Since migrant studies can distinguish environmental from genetic risk factors, we conducted a structured review of migrant studies and assessed prominent cancer website resources to determine evidence of gender bias between breast and prostate cancer.

METHODS

We searched ten online databases for articles with migration as the exposure and breast cancer mortality and/or incidence as the outcome. We also searched using prostate cancer as the outcome to generate a comparison group. We developed rubrics to categorize the studies by study design (single, double, and time dimensional), convergence (a change in incidence or mortality for the migrant population), and concordance (consistency between results and author-attributed etiology). We used chi-square tests to test for differences by cancer type. We web-scraped four notable cancer websites to extract website layouts, risk factor information, and language describing breast cancer etiology and compared it to the content used for prostate cancer.

FINDINGS

Of all 140 studies and 220 comparisons, breast (n = 131) outnumbered prostate cancer studies (n = 89; p-value = 0·005). For both cancers, studies that compared all three populations (the non-migrant, origin, and destination population outcomes) or measured length of stay demonstrated that cancer rates converged with migration. Most authors attributed breast cancer etiology to genetic and environmental factors. Yet, the migrant study results were inconsistent with public health messaging; all four websites framed breast cancer as more modifiable than prostate cancer.

CONCLUSION

Research efforts and public health messaging for breast cancer should consider gendered barriers to changing individual-level risk factors and develop more prevention strategies at the health systems level.

Racial and ethnic differences in second primary lung cancer risk among lung cancer survivors

BACKGROUND

Recent therapeutic advances have improved survival among lung cancer (LC) patients, who are now at high risk of second primary lung cancer (SPLC). Hispanics comprise the largest minority in the United States, who have shown a lower LC incidence and mortality than other races, and yet their SPLC risk is poorly understood. We quantified the SPLC incidence patterns among Hispanics vs other races.

METHODS

We used data from the Multiethnic Cohort, a population-based cohort of 5 races (African American, Japanese American, Hispanic, Native Hawaiian, and White), recruited between 1993 and 1996 and followed through 2017. We identified patients diagnosed with initial primary lung cancer (IPLC) and SPLC via linkage to Surveillance, Epidemiology, and End Results registries. We estimated the 10-year cumulative incidence of IPLC (in the entire cohort) and SPLC (among IPLC patients). A standardized incidence ratio (SIR) was calculated as the ratio of SPLC-to-IPLC incidence by race and ethnicity.

RESULTS

Among 202 692 participants, 6788 (3.3%) developed IPLC over 3 871  417 person-years. The 10-year cumulative IPLC incidence was lower among Hispanics (0.80%, 0.72 to 0.88) vs Whites (1.67%, 1.56 to 1.78) or Blacks (2.44%, 2.28 to 2.60). However, the 10-year SPLC incidence following IPLC was higher among Hispanics (3.11%, 1.62 to 4.61) vs Whites (2.80%, 1.94 to 3.66) or Blacks (2.29%, 1.48 to 3.10), resulting in a significantly higher SIR for Hispanics (SIR = 8.27, 5.05 to 12.78) vs Whites (SIR = 5.60, 4.11 to 7.45) or Blacks (SIR = 3.48, 2.42 to 4.84; P < .001).

CONCLUSION

Hispanics have a higher SPLC incidence following IPLC than other races, which may be potentially due to better survival after IPLC and extended duration for SPLC development. Continuing surveillance is warranted to reduce racial disparities among LC survivors.

Assessing racial, ethnic, and nativity disparities in US cancer mortality using a new integrated platform

BACKGROUND

Foreign-born populations in the United States have markedly increased, yet cancer trends remain unexplored. Survey-based Population-Adjusted Rate Calculator (SPARC) is a new tool for evaluating nativity differences in cancer mortality.

METHODS

Using SPARC, we calculated 3-year (2016-2018) age-adjusted mortality rates and rate ratios for common cancers by sex, age group, race and ethnicity, and nativity. Trends by nativity were examined for the first time for 2006-2018. Traditional cancer statistics draw populations from decennial censuses. However, nativity-stratified populations are from the American Community Surveys, thus involve sampling errors. To rectify this, SPARC employed bias-corrected estimators. Death counts came from the National Vital Statistics System.

RESULTS

Age-adjusted mortality rates were higher among US-born populations across nearly all cancer types, with the largest US-born, foreign-born difference observed in lung cancer among Black women (rate ratio = 3.67, 95% confidence interval [CI] = 3.37 to 4.00). The well-documented White-Black differences in breast cancer mortality existed mainly among US-born women. For all cancers combined, descending trends were more accelerated for US-born compared with foreign-born individuals in all race and ethnicity groups with changes ranging from -2.6% per year in US-born Black men to stable (statistically nonsignificant) among foreign-born Black women. Pancreas and liver cancers were exceptions with increasing, stable, or decreasing trends depending on nativity and race and ethnicity. Notably, foreign-born Black men and foreign-born Hispanic men did not show a favorable decline in colorectal cancer mortality.

CONCLUSIONS

Although all groups show beneficial cancer mortality trends, those with higher rates in 2006 have experienced sharper declines. Persistent disparities between US-born and foreign-born individuals, especially among Black people, necessitate further investigation.

Geographic Variation and Risk Factor Association of Early Versus Late Onset Colorectal Cancer

The proportion of patients diagnosed with colorectal cancer (CRC) at age < 50 (early-onset CRC, or EOCRC) has steadily increased over the past three decades relative to the proportion of patients diagnosed at age ≥ 50 (late-onset CRC, or LOCRC), despite the reduction in CRC incidence overall. An important gap in the literature is whether EOCRC shares the same community-level risk factors as LOCRC. Thus, we sought to (1) identify disparities in the incidence rates of EOCRC and LOCRC using geospatial analysis and (2) compare the importance of community-level risk factors (racial/ethnic, health status, behavioral, clinical care, physical environmental, and socioeconomic status risk factors) in the prediction of EOCRC and LOCRC incidence rates using a random forest machine learning approach. The incidence data came from the Surveillance, Epidemiology, and End Results program (years 2000-2019). The geospatial analysis revealed large geographic variations in EOCRC and LOCRC incidence rates. For example, some regions had relatively low LOCRC and high EOCRC rates (e.g., Georgia and eastern Texas) while others had relatively high LOCRC and low EOCRC rates (e.g., Iowa and New Jersey). The random forest analysis revealed that the importance of community-level risk factors most predictive of EOCRC versus LOCRC incidence rates differed meaningfully. For example, diabetes prevalence was the most important risk factor in predicting EOCRC incidence rate, but it was a less important risk factor of LOCRC incidence rate; physical inactivity was the most important risk factor in predicting LOCRC incidence rate, but it was the fourth most important predictor for EOCRC incidence rate. Thus, our community-level analysis demonstrates the geographic variation in EOCRC burden and the distinctive set of risk factors most predictive of EOCRC.