Keywords

Introduction

Breast cancer is the leading cause of cancer death among US Hispanic women [1]. In Hispanic women, breast cancer tends to be diagnosed at an earlier age, at a more advanced stage, and with more aggressive phenotypes, compared to non-Hispanic Whites (NHW) [1], similar to what has been reported for African American/Black (referred to hereafter as Black) women [2]. Because Hispanics are the fastest growing group in the United States [3] and cancer survival is improving [4], the population of Hispanic breast cancer survivors is increasing. However, this is an understudied population that is more vulnerable to cancer inequities as they tend to have lower socioeconomic status (SES) and poorer access to care [1]. Hispanic breast cancer survivors are also likely to experience increasing rates of obesity and related comorbidities, such as diabetes [5], which place further burden in their cancer care and survivorship.

Both Hispanic and Black women have a high prevalence of obesity [6] but have distinct patterns of obesity-related comorbidities and biomarkers [7,8,9]. Hispanic women are also more susceptible than other racial/ethnic groups to weight gain [10], which primarily results in abdominal accumulation of adipose tissue, with negative metabolic effects [11]. As a consequence, metabolic syndrome, insulin resistance, diabetes, and dyslipidemia are common among Hispanics [12, 13]. They have the highest prevalence of central obesity and metabolic syndrome of any racial/ethnic group [10], which has been linked to an increased risk of aggressive breast cancer subtypes [14, 15]. Obesity and related comorbidities can impact breast cancer treatment [16,17,18] but little is known about their independent impact on breast cancer treatment in Hispanic women. Obesity has also been shown to have a negative impact on patient-reported outcomes (PROs) including quality of life (QoL), fatigue, and lymphedema [19]; Hispanic women also experience poorer QoL after diagnosis [20, 21], but the role of obesity and related factors on PROs among Hispanic women is not well understood. Weight changes are common and a major cause of distress [22,23,24], with implications for comorbid conditions and potentially a factor in treatment adherence among cancer survivors.

Obesity and Breast Cancer Treatment

Receipt of guideline-concordant care is associated with more favorable breast cancer outcomes, but both Hispanic and Black breast cancer patients experience reductions in treatment intensity compared to NHW [25]. Obesity contributes to underdosing due to dose capping [26, 27], and breast cancer patients with comorbid conditions are less likely to receive surgery, radiotherapy, and adjuvant chemotherapy [28,29,30,31], and to be less adherent to hormonal therapy [32, 33]. The management and control of obesity-related conditions, such as diabetes and hypertension, may be particularly relevant since these conditions explain up to 30–50% of the survival disparity observed in Black breast cancer patients [10, 34,35,36,37]. Also, adherence to chronic disease medications, including statins for hyperlipidemia and oral medications for type 2 diabetes, declines during and after breast cancer treatment [38, 39]. Racial/ethnic differences exist in the prevalence and management of various comorbidities [40,41,42], treatments prescribed [41], and medication adherence [38, 43] and may have differential impacts on breast cancer treatment and PROs. The types of medications used to treat obesity-related conditions can also vary by racial/ethnic group. Hispanics are less likely than Black women to be prescribed a diuretic or calcium channel blocker for hypertension but are more likely to use a β-blocker [41]. To date, little is known about how management of comorbid conditions affects breast cancer treatment among breast cancer survivors, particularly in minority groups who have lower access to care [44, 45], but it is a key question given the clear link between comorbidities and poorer outcomes in breast cancer survivors [18].

Obesity and Patient-Reported Outcomes

Breast cancer survivors often develop symptoms and psychosocial effects related to their diagnosis and treatments. As a consequence, PROs such as cancer-related QoL, symptoms, and psychosocial factors are increasingly being considered key in cancer survivorship [46]. Because Hispanic women tend to have more advanced diagnoses and aggressive treatments [20], PROs are particularly important in this population. Hispanic breast cancer survivors generally report worse mental, physical, and social QoL than NHWs after diagnosis [20], but most studies had small sample sizes, used a cross-sectional design, and had limited scope. Obesity and related comorbidities have been shown to negatively impact PROs [47,48,49], but associations are not well understood, and few studies have focused on Hispanic breast cancer survivors. Being overweight has been shown to be associated with better QoL, but being obese was associated with lower physical, but not mental health in a study among 69 Hispanic long-term breast cancer survivors in New Mexico [21]. In the Women’s Healthy Eating and Living Study, obesity was associated with both lower physical and mental health among Hispanic breast cancer survivors approximately 2 years after diagnosis (n = 165) [50]. These results are intriguing and warrant further research to fully evaluate the impact of obesity-related factors on PROs, with consideration of a range of key factors among Hispanic breast cancer survivors.

Feasibility of Assembling a Population-Based Hispanic Breast Cancer Survivors Cohort: The New Jersey Hispanic Breast Cancer Survivors Study (NJHBS) Pilot

With the long-term goal of evaluating the impact of obesity-related factors among Hispanic women after a breast cancer diagnosis, we conducted a pilot study to assess the feasibility of assembling a cohort study of Hispanic breast cancer survivors in New Jersey and their willingness to donate biological specimens and engage in follow-up activities. The methodology used in the New Jersey Hispanic Breast Cancer Survivors Study (NJHBS) pilot was similar to that used in our established cohort of Black breast cancer survivors in New Jersey, the Women’s Circle of Health Follow-Up Study (WCHFS) [51], to allow direct comparisons of two populations vulnerable to cancer inequities.

Methods

The WCHFS, described in detail elsewhere [51], is a population-based cohort study of Black breast cancer survivors, identified in ten counties in New Jersey through rapid case ascertainment by the New Jersey State Cancer Registry. Self-identified Black or African American women with newly diagnosed, histologically confirmed ductal carcinoma in situ (DCIS) or invasive breast cancer, aged 20–75 years with no previous history of cancer other than non-melanoma skin cancer, and able to speak and read English, were eligible to participate. Pre-diagnosis data on established or suspected risk factors for breast cancer, as well as a saliva sample and detailed body measurements, were collected during a baseline in-person interview approximately 9 months after diagnosis. Follow-up was conducted by recontacting cases annually, including two post-treatment home visits at approximately 24 months and 36 months post-diagnosis and a phone interview at ~48 and ~60 months post-diagnosis to obtain information on survivorship factors of interest, as well as to update medical and lifestyle information and ascertain new breast cancer events or other cancers. Annual linkage with the New Jersey State Cancer Registry provides information on clinical characteristics, treatment and other cancer events, and mortality outcomes.

The NJHBS pilot study used a similar methodology to that used in WCHFS with some differences due to budget constraints, including a more limited target area (6 counties in New Jersey) and only one home visit for data collection. Because we were interested in assessing survivorship needs, the timing of the home visit for the pilot corresponded to the follow-up 1 visit in WCHFS (i.e., approximately 24 months after diagnosis). In the pilot, women who were proficient in English and/or Spanish were able to participate.

Methods for recruitment and data collection were similar to those in WCHFS [51]. After confirming eligibility, we scheduled a home visit to obtain informed consent, administered questionnaires using computer-assisted interviewing, and obtained body measurements and a saliva sample for DNA extraction using WCHFS protocols [51].

Validated scales and validated Spanish versions of questionnaires were used when possible. Acculturation was assessed in the NJHBS pilot using the Short Acculturation Scale for Hispanics (SASH) [52, 53], which includes 12 items with 3 subscales: language use, media, and ethnic social relations. Responses to all items are given on a five-point Likert scale where 1 is “Only Spanish” and 5 is “Only English.” Low acculturation is defined as a SASH average score below 2.99 [52]. We also asked questions on migration status (foreign/US born), age at migration, and generation (e.g., first, second generation).

Breast cancer-related QoL was assessed in both the WCHFS and NJHBS pilot using the Functional Assessment of Cancer Therapy, Breast scale (FACT-B+4) [54], which is available in English and Spanish and has been validated in Hispanic populations [55, 56].

Remaining questions (e.g., sociodemographic factors and reproductive and medical history) in the pilot questionnaire were translated by professional translators. Questionnaires were administered in the participants’ choice of language (i.e., English or Spanish), with the Spanish version administered by a bilingual Spanish-speaking interviewer.

Results

Despite budget and time constraints in the NJHBS pilot study, we were able to recruit 102 Hispanic breast cancer survivors in approximately 5 months. This included time for New Jersey State Cancer Registry staff to identify potential participants; request physician permission by mail to contact the patient, allowing 3 weeks for response; seek patient permission to release contact information to Rutgers Cancer Institute of New Jersey staff; and schedule and carry out a home visit with the participant. Among those with confirmed eligibility, the cooperation rate was higher in Hispanic women than in Black women (92% vs. 83%). The majority of participants in the pilot donated saliva (98%, same as in WCHFS), 92% said they were willing to donate a blood sample, and 95% were interested in participating in future studies. These rates suggest that Hispanic breast cancer survivors have high interest and willingness to participate in research studies.

As expected, based on New Jersey demographics [57, 58], almost half of the population was Caribbean (Fig. 14.1), with wide heterogeneity in country of origin. Approximately 61% said they were White, 20% Black, 23% Indigenous, and 19% mixed race. Acculturation was low in the NJHBS pilot study based on SASH [52], with 87% being foreign-born, 79% moving to the United States as adults, and 86% speaking only Spanish (data not shown). Compared to Black breast cancer survivors, Hispanic breast cancer survivors were less educated (52.9% vs. 36.2% had a high school education or less), had lower income (50% vs. 36.2% with a household annual income <25K), were less likely to have health insurance (18% vs. 11%), and more likely to report that cancer had caused them financial hardship (61.7% vs. 43.2%) (Table 14.1).

Fig. 14.1
A pie chart on breast cancer survivors of the Caribbean at 45 and South America at 39 per cent. Puerto Rico 15, Dominican 20, Cuba 10, Peru 13, Colombia 14, Central America 12, Mexico 3, and other 13.

Hispanic origin in the New Jersey Hispanic Breast Cancer Survivors Study (NJHBS) Pilot (n = 102)

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Table 14.1 Demographic, clinical, and treatment characteristics of participants in the New Jersey Hispanic Breast Cancer Survivors Study (NJHBS) pilot and the Women’s Circle of Health Follow-Up Study (WCHFS)
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When we compared treatment information from the New Jersey State Cancer Registry on participants in the NJHBS pilot study with Black women in WCHFS, we found that Hispanic breast cancer survivors were more likely to not have surgery than Black breast cancer survivors (13.7% vs. 6.5%) despite being more likely to have invasive cancer, and those who did were less likely to have breast-conserving surgery (49% vs. 61%) (Table 14.1).

Hispanic and Black breast cancer survivors were shown to have different patterns of obesity and obesity-related comorbidities. As shown in Fig. 14.2, Hispanics were more likely to be overweight or obese overall (85% vs. 82%), but Black women were more likely to be severely obese. Central obesity (waist circumference > 88 cm) was higher in Hispanic women at every level of body mass index (BMI) (data not shown). Overall, excess body fat was high in both groups, with 77.4% of Hispanic and 85% of Black breast cancer survivors having >35% percent body fat, and 68% of both Black and Hispanic women having central obesity (waist-to-hip ratio > 0.85) (data not shown). Hispanics were more likely to have diabetes (28.4% vs. 22.3%) and hypercholesterolemia (51% vs. 47%), while Black women were more likely to have hypertension (58.4% vs. 36.3%), but all these obesity-related comorbidities were highly prevalent in both groups. These differences may result in different metabolic consequences relevant to disease prognosis. Further work is needed to understand the complex impact of obesity on various breast cancer subtypes and the mechanistic pathways relevant to disease prognosis that may be differentially affected by obesity and related comorbidities across different racial/ethnic populations [59].

Fig. 14.2
Two bar graphs on breast cancer survivors. The lowest in underweight 0.4, 2.0 in obese 3, and the highest central obesity are more than W C 88 cm is 68.6, 67.6 in black and Hispanic women respectively.

Comparing Participants in the New Jersey Hispanic Breast Cancer Survivors Study Pilot versus Black Breast Cancer Survivors in the Women’s Circle of Health Follow-Up Study. 1A (top): Distributions of weight status based on body mass index (BMI); 1B (bottom): Prevalence of obesity and related comorbidities. BMI was calculated by measured weight and height at approximately 24 months after diagnosis in both populations

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We compared breast cancer-related QoL measures using the FACT-B scales [54,55,56] among Hispanics and Black breast cancer survivors participating in the NJHBS pilot study and WCHFS. Physical, social/family, functional, and emotional well-being, and overall QoL scores (Fig. 14.3) were consistently lower among Hispanics. Obese Hispanic breast cancer survivors had the lowest QoL scores and particularly lower physical and functional well-being. Over 50% of Hispanic and 33% of Black breast cancer survivors said that they were bothered by weight changes, which affected their QoL scores. In future analyses, we plan to explore explanations for these findings by evaluating predictors of QoL in both populations and whether associations with BMI persist after adjusting for other factors.

Fig. 14.3
Six bar graphs of non-obese, obese survivors of breast cancer in Hispanic and black women. Physical, Functional, Social or Family, Emotional well-being, Breast cancer Subscale, and Fact-B total score.

Health-Related Quality of Life Measures Among Obese and Non-Obese Women Comparing Participants in the New Jersey Hispanic Breast Cancer Survivors Study Pilot versus Black Breast Cancer Survivors in the Women’s Circle of Health Follow-Up Study

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Summary

Our feasibility study among Hispanic breast cancer survivors demonstrated that Hispanic breast cancer survivors are very willing to participate in cohort studies and to donate biospecimens, consistent with what has been reported by others [60, 61]. We also found high financial distress due to cancer and intriguing treatment differences between Hispanic and Black breast cancer survivors. Obesity, central obesity, and comorbidities were highly prevalent in both populations, with Hispanic breast cancer survivors having higher rates of central obesity at each BMI category and higher rates of diabetes. Consistent with the few studies addressing QoL in Hispanic breast cancer survivors [20], we found lower overall breast cancer-related QoL scores for Hispanic breast cancer survivors, particularly for obese women.

Hispanics are a genetically admixed population with European, Indigenous American, and African Ancestry [62]. Historical factors account for the wide variations in admixture, with Puerto Ricans and Dominicans showing the largest proportion of African ancestry, while Mexicans show large proportions of Indigenous ancestry [63]. Genetic ancestry has been correlated with obesity-related physiologic measurements, adiposity, and risk of obesity-related comorbidities, including diabetes and hypertension among Hispanic and Black populations [64,65,66,67,68,69,70]. African admixture has been associated with BMI in Black women, but among Hispanic women, Indigenous American ancestry was strongly associated with waist-to-hip ratio, but not BMI [71]. Given this heterogeneity in obesity phenotypes and genetic ancestry, future studies need to address how genetic ancestry, obesity phenotypes, and related comorbidities affect aggressive breast cancer presentation, treatment, and survivorship factors by race/ethnicity.

Unfortunately, the heterogeneity of Hispanics is often raised by reviewers as a significant weakness when evaluating research in this population, as a single study is unlikely to have statistical power to evaluate associations by subgroups based on country of origin. However, there are unifying cultural themes across different subgroups (e.g., family values, religion/spirituality, perception of health and sickness), and only by starting to collect data on Hispanic breast cancer survivors, we will be able to dissect if indeed there are differences in the way breast cancer affects patient-reported outcomes and prognosis by Hispanic origin in the future and the complex interactions between race/ethnicity, culture, and ancestry. Despite increased interest in survivorship research, there is still a critical need to understand and address the needs of Hispanic breast cancer survivors, a growing and vulnerable population.