Risk of second primary cancer among women in the Kaiser Permanente Breast Cancer Survivors Cohort

Variation in patterns of second primary malignancies across U.S. race and ethnicity groups: a Surveillance, Epidemiology, and End Results (SEER) analysis

PURPOSE

One in six incident cancers in the U.S. is a second primary cancer (SPC). Although primary cancers vary considerably by race and ethnicity, little is known about the population-based occurrence of SPC across these groups.

METHODS

Using Surveillance, Epidemiology, and End Results (SEER) 12 data and relative to the general population, we calculated standardized incidence ratios (SIRs) and 95% confidence intervals (CIs) for SPC among 2,457,756 Hispanics, non-Hispanic Asian American/Pacific Islanders (NHAAPI), non-Hispanic black (NHB), and non-Hispanic whites (NHW) cancer survivors aged 45 years or older when diagnosed with a first primary cancer (FPC) from 1992 to 2015.

RESULTS

The risk of second primary bladder cancer after first primary prostate cancer was higher than expected in Hispanic (SIR = 1.18, 95% CI: 1.01-1.38) and NHAAPI (SIR = 1.41, 95% CI: 1.20-1.65) men than NHB and NHW men. Among women with a primary breast cancer, Hispanic, NHAAPI, and NHB women had a nearly 1.5-fold higher risk of a second primary breast cancer, while NHW women had a 6% lower risk. Among men with prostate cancer whose SPC was diagnosed 2 to <12 months, NHB men were at higher risk for colorectal cancer and Hispanic and NHW men for non-Hodgkin's lymphoma. In the same time frame for breast cancer survivors, Hispanic and NHAAPI women were significantly more likely than NHB and NHW women to be diagnosed with a second primary lung cancer.

CONCLUSION

Future studies of SPC should investigate the role of shared etiologies, stage of diagnosis, treatment, and lifestyle factors after cancer survival across different racial and ethnic populations.

Second primary cancer risks according to race and ethnicity among U.S. breast cancer survivors

Breast cancer survivors have an increased risk of developing second primary cancers, yet risks by race and ethnicity have not been comprehensively described. We evaluated second primary cancer risks among 717,335 women diagnosed with first primary breast cancer (aged 20-84 years and survived ≥1-year) in the SEER registries using standardized incidence ratios (SIRs; observed/expected). SIRs were estimated by race and ethnicity compared with the racial- and ethnic-matched general population, and further stratified by clinical characteristics of the index breast cancer. Poisson regression was used to test for heterogeneity by race and ethnicity. SIRs for second primary cancer differed by race and ethnicity with the highest risks observed among non-Hispanic/Latina Asian American, Native Hawaiian, or other Pacific Islander (AANHPI), non-Hispanic/Latina Black (Black), and Hispanic/Latina (Latina) survivors and attenuated risk among non-Hispanic/Latina White (White) survivors (SIRAANHPI = 1.49, 95% CI = 1.44-1.54; SIRBlack = 1.41, 95% CI = 1.37-1.45; SIRLatina = 1.45, 95% CI = 1.41-1.49; SIRWhite = 1.09, 95% CI = 1.08-1.10; p-heterogeneity<.001). SIRs were particularly elevated among AANHPI, Black, and Latina survivors diagnosed with an index breast cancer before age 50 (SIRs range = 1.88-2.19) or with estrogen receptor-negative tumors (SIRs range = 1.60-1.94). Heterogeneity by race and ethnicity was observed for 16/27 site-specific second cancers (all p-heterogeneity's < .05) with markedly elevated risks among AANHPI, Black, and Latina survivors for acute myeloid and acute non-lymphocytic leukemia (SIRs range = 2.68-3.15) and cancers of the contralateral breast (SIRs range = 2.60-3.01) and salivary gland (SIRs range = 2.03-3.96). We observed striking racial and ethnic differences in second cancer risk among breast cancer survivors. Additional research is needed to inform targeted approaches for early detection strategies and treatment to reduce these racial and ethnic disparities.

Catastrophic health expenditures, insurance churn, and non-employment among women with breast cancer

BACKGROUND

Breast cancer treatment and survivorship entails a complex and expensive continuum of subspecialty care. Our objectives were to assess catastrophic health expenditures, insurance churn, and non-employment among women younger than 65 years who reported a diagnosis of breast cancer. We also evaluated changes in these outcomes related to implementation of the Affordable Care Act.

METHODS

The data source for this study was the Medical Expenditure Panel Survey (2005-2019), which is a national annual cross-sectional survey of families, providers, and insurers in the United States. To assess the impact of breast cancer, comparisons were made with a matched cohort of women without cancer. We estimated predicted marginal probabilities to quantify the effects of covariates in models for catastrophic health expenditures, insurance churn, and non-employment.

RESULTS

We identified 1490 respondents younger than 65 years who received care related to breast cancer during the study period, representing a weight-adjusted annual mean of 1 062 129 patients. Approximately 31.8% of women with breast cancer reported health expenditures in excess of 10% of their annual income. In models, the proportion of women with breast cancer who experienced catastrophic health expenditures and non-employment was inversely related to increasing income. During Affordable Care Act implementation, mean number of months of uninsurance decreased and expenditures increased among breast cancer patients.

CONCLUSIONS

Our study underscores the impact of breast cancer on financial security and opportunities for patients and their families. A multilevel understanding of these issues is needed to design effective and equitable strategies to improve quality of life and survivorship.