Abstract
Background/Aim: This study aimed to identify the demographic/socioeconomic factors associated with disparities in time to breast cancer treatment. Patients and Methods: We conducted an analysis of breast cancer patients from the National Cancer Database, 2008-2019. Time intervals from diagnosis to surgery, radiation, and chemotherapy were compared based on age, sex, race, and socioeconomic status. Results: A total of 715,210 patients with breast cancer were included. Overall, Hispanic patients had the longest times to surgery, radiation, and chemotherapy compared to non-Hispanic patients (surgery 73.3 vs. 53.8 days, radiation 177.2 vs. 136.9 days, chemotherapy 83.0 vs. 66.5 days, all p<0.01). Similarly, black patients, those who were uninsured, and those with lower income (<$63,000) had the longest times to treatment. Conclusion: We identified several racial/socioeconomic disparities in time to treatment. Further investigation into the causes of these disparities is of increasing importance to address inequities in breast cancer care.
According to the National Cancer Institute, breast cancer is the second most common cancer in women after skin cancer. While the mortality rate of breast cancer has decreased in the last few decades (1), disparities in cancer treatment still exist. In the past, factors, such as race, seemed to play a major role in research studies with the results showing that outcomes in patients with breast cancer were worse for black women and other ethnic groups such as Hispanic groups when compared to white women (2). Scientific studies have shown that genetics and biological properties may play a significant role in the morbidity and mortality of a patient with breast cancer (3). However, multiple studies indicate that the outcomes of breast cancer treatments are multifactorial, and treatment delays may significantly impact disease staging and treatment outcomes (4). Factors that result in treatment delay include the patient’s insurance, financial status, and demographics. Disparities in time to treatment need to be identified and brought to attention in order to decrease the gap in access to breast cancer treatment.
Patients and Methods
We conducted a retrospective study between 2004 and 2019 using the National Cancer Database (NCDB). Institutional Review Board approval was not required for the study.
Patients with breast cancer of stages, as per the American Joint Committee on Cancer (AJCC 6th and 7th edition) guidelines, were included. Variables in the analysis included age, sex, race, Hispanic origin, insurance status, income, treatment facility type, geographic location (rural/urban), grade, cancer stage, and Charlson-Deyo Comorbidity (CDC) score. Times to treatment (surgery, chemotherapy, and/or radiation) were computed and summarized.
Statistical analysis was performed using SAS version 9.4 (SAS Institute Inc., Cary, NC, USA). The clinical and demographic characteristics, disease outcome measures, and treatment variables were summarized. The mean, median, standard deviation, and ranges were provided for continuous variables and analyzed using the Kruskal–Wallis test. The frequencies and relative frequencies were provided for categorical variables and analyzed using chi-square tests.
Results
Time to first treatment. The time to first treatment for breast cancer is an important interval when determining how delay of treatment impacts patient outcome. Many studies have reported that delay in receiving breast cancer diagnosis and treatment resulted in worse overall survival rates, especially when the treatment delays were longer than 90 days post diagnosis. Delaying adjuvant therapy resulted in worse survival rates in patients who underwent surgery in less than 90 days post diagnosis (5, 6). When comparing factors that contributed to the time of first treatment for breast cancer, Hispanic patients and uninsured patients had the longest time interval until their first treatment (Table I). Those patients treated at academic facilities also had the longest time interval to first treatment when compared to other facility types. For all outcomes, time to treatment had no association with overall survival (OS).
Time to first treatment.
Time to surgery. Racial disparities in accessing health care have been shown to have a significant impact on patient outcomes (7). Black women are more likely to die from breast cancer when compared to white women (8). Results published by Best et al. demonstrated racial disparity in getting major surgical procedures in the US whereby a lower rate of black patients received major surgery when compared to their white counterparts (9). In our study, 86.2% of our study population received surgery. As shown in Table II, our study showed that compared to other races, black women had a significantly longer time to definitive surgery of 71.70 days (standard deviation of 74.73 days). In addition, patients of Hispanic origin had the longest time interval between diagnosis and first surgery, 73.26 days. Demographically, patients who live in metropolitan areas had longer time intervals to definitive surgery, 54.92 days, when compared to those in urban, 49.37 days, or rural areas, 50.07 days. Patients who were uninsured also had significantly longer time intervals to surgery treatment, 79.75 days, when compared to their insured counterparts, private insurance, 57.21 days, or government insurance of 50.38 days. Patients who underwent definitive breast surgery at an academic facility took a longer time to receive surgery, 61.64 days, when compared to other facilities such as community of 49.30 days, or comprehensive facility of 50.53 days (Table II).
Time to surgery.
Time to radiation. Radiation therapy is an important treatment to comprehensively treat patients with breast cancer. In our study, 42.0% of our study population required radiation therapy as an adjuvant therapy. Compared to the data from the other cancer types, interestingly, patients with breast cancer had the longest time interval to radiotherapy, with a mean of 138.23 days (standard deviation of 89.81 days). When compared to other races, black women had significantly longer time interval to radiation therapy of 172.07 days (standard deviation of 101.78 days). In addition, patients of Hispanic origin had the longest time interval to radiation treatment of 177.20 days (standard deviation of 107.32 days). Patients who were uninsured also had significantly longer time intervals, 185.55 days, to radiation treatment when compared to patients who were insured. In addition, patients with an income of less than $63,000 yearly also took longer to receive their radiation treatment with a mean of 141.05 days. Patients who received radiation therapy at an academic facility also had a time interval of 185.55 days, when compared to other facility types (Table III).
Time to radiation.
Time to chemotherapy. According to the American Cancer Society chemotherapy has recently been used as an adjuvant or neoadjuvant therapy (10). It has been shown in previous studies that black breast cancer patients experience increased delays in the initiation of adjuvant chemotherapy when compared to other ethnic groups which may be due to biological factors, increased risk for infection, or socioeconomic background (11). However, as shown in Table IV, our study showed that Native Americans take the longest time when compared to other ethnic groups with a mean of 73.45 days (standard deviation of 59.95 days) to receive chemotherapy treatment. Like other breast cancer treatments, patients of Hispanic origin take longer to receive their chemotherapy treatment, 82.95 days (standard deviation of 67.41 days).
Time to chemotherapy.
Discussion
In our analysis, multiple socioeconomic factors and demographics played a significant role in time to breast cancer treatment (12-14). According to American Cancer Society, Hispanic patients often have lower levels of education, are more likely to live in poverty, face many barriers to healthcare, and are less likely to have health insurance when compared to other ethnic groups (15). Our study showed that Hispanic women experienced delay in receiving all aspects of breast cancer treatment when compared to women who are not of Hispanic origin. In addition to factors such as socioeconomic disadvantages among the Hispanic population, cultural factors may also play a significant role in the ability of Hispanic patients to access breast cancer care (16). Furthermore, previous studies also showed that Hispanic women are less likely to be diagnosed with breast cancer at an early stage and are more likely to be diagnosed with hormone receptor negative breast cancer both of which result in more complex treatment (17, 18). Taken together, this disparity identified among Hispanic women on receiving breast cancer care may be quite pervasive.
In addition to Hispanic origin, our study found that black women also experienced a longer time to receive breast cancer treatments when compared to other races. Many previous studies have raised concern about the mortality rate in black women with breast cancer. Studies have shown that African Americans have less access to breast cancer screening, prevention, and treatments when compared to other populations (19). The American Cancer Society also suggests that in areas highly populated by African Americans, women have difficulty receiving essential healthcare which results in late diagnosis, higher motility rates, and poorer outcomes (20). With an increased time interval for receiving breast cancer treatment when compared to other races, our data supports the inequity for black women to receive breast cancer treatment.
Socioeconomic status has been shown to play a significant factor for women to receive breast cancer treatment (21). Insurance status at time of breast cancer impacts the mortality rate of patients with breast cancer, whereby women without insurance are more likely to be diagnosed in later cancer stage when compared with those who have insurance. This in turn results in delayed treatment and higher mortality in women with lower socioeconomic status (22). In our study, patients with an income of less than $63,000 per year and women without insurance were significantly more likely to have delays in receiving breast cancer treatment. A previous study by Kwabeng et al. found a strong correlation between insurance coverage and patient survival (23). While we found no association between the time to treatment disparities and OS rate, we believe that socioeconomic disadvantage and lack of insurance coverage when combined with other factors that were not available within the NCDB may potentially have impact on breast cancer outcomes.
In addition to race/ethnicity and socioeconomic status, another factor that contributes to treatment disparities is demographic location. Previous studies have focused on the correlation of zip code with breast cancer treatment adherence and outcome (24). Interestingly, our data suggested that women with breast cancer who live in a metropolitan area take a significantly longer time to receive their breast cancer treatment. Specifically, one of the factors that affect the time to receive breast cancer treatment is hospital type. Our data indicated that there was a significantly longer time to treatment for patients who received care at academic hospitals when compared to other hospital types. According to a study by Shariff-Marco et al., most African American women with breast cancer received their cancer care in an academic setting following referral from another hospital (25). Referral time likely plays a significant role in the timely treatment of patients with breast cancer in an academic hospital setting. In addition to slower referral time, a higher volume of cases and less flexibility in scheduling also contribute to the delay in receiving treatment. However, due to limited data within the NCDB to investigate these factors, more granular analysis is needed.
As our study is retrospective and derived from a large database analysis, we acknowledge several limitations. Recall bias and missing data limit the reliability and generalizability of our conclusions. In addition, although there was no association between disparity in time to breast cancer treatment and OS, the NCDB does not include other treatment outcomes (e.g., quality of life, recurrence-free survival, or progression-free survival) that may be impacted by these disparities.
In conclusion, our findings suggest that social determinants of health have a significant impact on the disparity in time to breast cancer treatment. Physicians and healthcare providers should be aware of these factors and advocate for breast cancer patients to receive the care and treatment they need and narrow this gap in breast cancer treatment.
Footnotes
Authors’ Contributions
Writing and revision of paper: KS, EG. Analysis and interpretation of data: KA, AG, KS, EG. Other: A.A.K, MA, KP. All Authors read and approved the final manuscript.
Conflicts of Interest
The Authors have no conflicts of interest to declare in relation to this study.
- Received September 4, 2022.
- Revision received October 30, 2022.
- Accepted November 9, 2022.
- Copyright © 2022 The Author(s). Published by the International Institute of Anticancer Research.
This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY-NC-ND) 4.0 international license (https://creativecommons.org/licenses/by-nc-nd/4.0).
