Body mass index but not percentage weight loss was associated with the race/ethnicity of patients with advanced lung cancer: a cross-sectional study

Introduction

Persistent and refractory weight loss is common in patients with cancer near the end of their lives, which contributes to a decreased quality of life (1,2). Cancer cachexia [usually defined as >5 percentage weight loss in the preceding 6 months, or weight loss greater than 2% in individuals with a body mass index (BMI) of <20 kg/m² or with sarcopenia (3)] is a multifactorial syndrome that cannot be fully reversed by conventional nutritional support and is associated with progressive functional impairment (4). Whether the self-reported racial/ethnic status of patients referred to Palliative Medicine, including Asian or Hispanic, is associated with percentage weight loss or BMI has not been investigated. So, we conducted this study to identify whether the race/ethnicity of patients with advanced lung cancer, a condition with high prevalence of cachexia (5), is associated with BMI or percentage weight loss. Our hypothesis was that Black and Hispanic patients would experience higher percentage of weight loss compared to Asians and non-Hispanic-Whites. Our primary objective was to determine if self-identified race/ethnicity of patients with advanced lung cancer was associated with percentage weight loss or BMI in patients with advanced lung cancer.

Additionally, since it has been reported that socioeconomic and insurance status play significant roles in the progression of weight loss in patients with lung cancer (6,7), the secondary objective of the study was to determine if social support, income level, insurance status were associated with weight changes in patients with advanced cancer. Determining factors associated with increased risk for cancer cachexia would help identify patients who would need early access to dietitians and aggressive treatments to prevent weight loss. We present this article in accordance with the STROBE reporting checklist (available at https://apm.amegroups.com/article/view/10.21037/apm-25-113/rc).

Methods

In this cross-sectional study, patients were selected from a pool of 1,253 patients with advanced lung cancer who were seen on 1^st consultation with Palliative Medicine during the study period of January 1, 2017 through December 31, 2022. The 1,253 patients were classified by their self-identified racial/ethnic group: Asian (n=121), African American (n=142), non-Hispanic Whites (n=884), and Hispanic (n=106). One hundred patients from each racial/ethnic group were randomly selected. To be included in the final analysis, patients needed to be older than 18 and to carry a diagnosis of advanced lung cancer, defined as metastatic disease, surgically un-resectable or undergoing a second or more line of chemotherapy. In addition, 6 Asian, 6 Black, 13 Hispanic and 9 non-Hispanic-White patients were excluded due to incomplete records, resulting in the following number of patients in each racial/ethnic group: Asian (n=94), Black (n=94), Hispanic (n=87), and non-Hispanic-White (n=91) patients. The study was conducted in accordance with the Declaration of Helsinki and its subsequent amendments. The study was approved by the Institutional Review Board of the University of Texas MD Anderson Cancer Center (Protocol # 2023-0082), and individual consent for this retrospective analysis was waived.

Data collected included demographics, social support (marital status, living alone), postal code, the Eastern Cooperative Oncology Group (ECOG) performance status (8), weight history (at first visit, consultation to Palliative Medicine, and last recorded), BMI (calculated as the weight in kilograms divided by the square of the height in meters), the symptom burden as measured by the Edmonton Symptom Assessment System (ESAS) (9), the morphine equivalent daily dose (MEDD), medications including appetite stimulants (megestrol, metoclopramide, mirtazapine, olanzapine, steroids, dronabinol, cannabidiol products), and nutritional laboratory markers such as albumin, protein level and the neutrophil-to-lymphocyte ratio (calculated by dividing the neutrophil by the lymphocyte counts). The United States Census Bureau website (https://data.census.gov/table/ACSST1Y2023.S1901?q=Income+(Households,+Families,+Individuals) was accessed on October 9, 2024 to obtain the median household income of the patients based on the postal code linked to their residential address was recorded.

Statistical analysis

Descriptive data were summarized using means and standard deviations (SD), or medians and interquartile ranges (IQR) for continuous variables, and percentages for categorical variables. To determine whether there is an association between percentage weight loss and race/ethnic groups, the cohort of patients with advanced lung cancer were divide by self-identified racial/ethnic designation and compared using analysis of variance (ANOVAs) (Tukey HSD) or Kruskal-Wallis test. Pairwise comparisons were made using a t-test or rank sum test. A multivariable regression linear analysis was performed with race/ethnic group, median household income, living alone, weight at first encounter, total symptoms score (measured by ESAS) and MEDD as the independent variables and weight loss (as the percentage weight loss from the pre-diagnosis to the last recorded weight) as the dependent variable. R (version 4.4.1) was used to perform all statistical analysis.

Results

The patient demographics, their social situation (i.e., marital status and approximate median household income), cancer-directed treatments (i.e., history of receiving chemotherapy, radiation treatment, surgery and/or immunotherapy), blood workup including markers of malnutrition and poor prognosis, appetite stimulants prescribed, and time from their initial appointment to our institution and the first Palliative Medicine consultation are presented in Tables 1 and 2. We noted some significant differences among the groups. Patients who identified as Asian, as compared to patients who identified as Black, Hispanic, or non-Hispanic White, had a significantly higher median household income (United States dollars: 100,359 vs. 68,394 vs. 77,085 vs. 79,947, P<0.001), were more likely to be married or have a significant other (86% vs. 45% vs. 71% vs. 69%, P<0.001), and less likely to live alone (9% vs. 23% vs. 11% vs. 18%, P=0.02), respectively.

Changes in BMI and weight over the disease trajectory are reported in Table 3. The Asian patients had significantly lower weight and BMI when compared to the other racial/ethnic groups at first encounter, Palliative Medicine consultation, and last recorded weight. The percentage change in weight was, however, not significantly different among the various race/ethnic groups. The total median (IQR) weight loss for the entire cohort was 10.4 (3.5–17.9) kg or 13.2% (5.0–22.5%) from the pre-diagnosis to the last recorded weight. When comparing all groups, Asians had a smaller absolute weight loss (8.2 kg) compared to Black (13.4 kg), Hispanic (9.1), or non-Hispanic-White (10.2 kg) patients, respectively (P=0.04), but the proportion of weight loss (%) was similar in all the groups (12.8 vs. 14.9 vs. 12.2 vs. 12.9; P=0.79), respectively. The self-identified Black patients had the greatest percentage of weight loss but were not significantly different compared to other racial/ethnic groups.

From presentation to a tertiary cancer center to the time of the first Palliative Medicine consultation, the whole population already lost weight, a median (IQR) 5.5 kg (0.9–11.1 kg) or 6.9% (1.1–14.0%) from the weight at first encounter, with no differences among the groups (Table 2). The median lapse in time (IQR) from the first Palliative Medicine consultation to the last recorded weight was 6.7 months (2.2–22.8 months) for the whole cohort; and they lost an additional median (IQR) 3.0 kg (−0.7 to 8.6 kg) or 4.2% (−0.1 to 12.3%) of body weight, again with no differences among the groups.

In the multivariable linear regression analysis (Table 4), the pre-diagnosis weight but not race/ethnicity was the only independent statistically significant variables associated with percentage weight loss.

Discussion

In this retrospective study, we found that in patients with advanced lung cancer who self-identified as Asians compared to Black, Hispanic and Non-Hispanic-White patients, had significantly lower weight and BMI at their initial visit to a tertiary cancer center, first Palliative Medicine consultation, and last recorded visit. Despite Asian patients having less absolute weight loss and lower BMI than the other groups, the percentage of weight loss was not significantly different among all the groups.

In addition, patients who identified as Asian were noted to have significantly higher median household income, more likely to be identified as married or have a significant other, and less likely to live alone. These findings regarding the socioeconomic characteristics are not unexpected and represent the overall demographics of the Asian population living in the United States. Previous investigations have reported that the self-identified Asian population had lower rates of obesity compared to Blacks, Hispanics or Non-Hispanic-Whites (10,11). According to the U.S. Census Bureau conducted in 2023, Asian households had the highest median income ($112,800), followed by Non-Hispanic-White ($89,050), Hispanic ($65,540), and Black households ($56,490) (12). Also, in a study to assess the risk of dying from cancer, Asian Americans were less likely to live alone compared to other race/ethnic groups (13).

A few studies of weight loss in patients with advanced cancer from different racial/ethnic groups have been published. In 2019, Permuth et al. conducted a retrospective analysis using data from cancer registries and hospitals in Florida, and reported a greater decrease in core and psoas musculature over time, lower baseline serum albumin levels, and higher platelet counts in Black patients with pancreatic cancer compared to non-Hispanic-Whites, suggesting that cachexia affected Black patients with pancreatic cancer disproportionately (14). In our study, Black patients had significantly higher levels of total serum protein but not albumin. A recent review noted lower albumin in a healthy population of Black patients (15). Albumin was not associated with race in patients with esophageal cancer undergoing esophagectomy (16) but was noted to be lower in Black patients at colon cancer diagnosis (17).

In 2021, Shang et al. studied 2,888 women with non-metastatic breast cancer and reported that Black patients had significant weight loss at 6, 18, 30, and 48 months from the time of diagnosis, while the body weight did not change in Asians, Hispanics and non-Hispanic-Whites (18). A recent study reported that Blacks and Hispanics had more than a 70% increased risk of presenting with cachexia at the time of diagnosis of stage 4 lung cancer with Black patients presenting at an average of 3 years younger than white patients (6). The same group also published that after controlling for potentially confounding covariates (age, sex, alcohol and tobacco history, comorbidity score, tumor site, histology, and stage) in patients with gastrointestinal cancer, Black and Hispanic patients had about 150% and 200% greater risk of cancer cachexia, respectively, than non-Hispanic-Whites (7). In contrast to these investigations, we found that race/ethnicity was not significantly associated with the percentage of weight loss in patients with advanced lung cancer referred to Palliative Medicine.

In addition, Asian Americans, who are less likely to live alone, have better socioeconomic conditions (higher household income), and are more likely to have medical insurance which provides timely access to medical care (19,20), still experienced the same proportion of weight loss compared with other ethnic/racial groups. The reasons for our findings remain speculative but could be explained by the realization that our patients were referred to Palliative Medicine, indicating that the patients were at the end of life and at risk of refractory cachexia. In fact, the lapse to the last recorded weight from the first consultation was only 6.7 months and the mean NLR ratio was >3 in all racial/ethnic groups implying a poor prognosis (21).

Importantly, the proportion of weight loss and the BMI have been identified as independent predictors of survival in patients with cancer and a prognostic grading system incorporating both has been developed (22). But our study suggests that since race/ethnic variations in BMI exist, prognostic tools should also account for race/ethnic backgrounds of patients to improve accuracy. In addition, cachexia diagnostic criteria (3), which includes BMI, should account for race/ethnic variations. Our study would indicate that more patients who self-identify as Asian would be more likely to be diagnosed with cachexia using BMI cut-off values than other race/ethnic groups. However, the role of BMI in various diverse race/ethnic groups is unclear. In a pooled analysis of 20,937 patients with non-small cell lung cancer, underweight and obese white female patients who were smokers had worse outcomes, while these associations were not found in Asian patients (23). In addition, Black patients had a better clinical outcome in the extreme BMI values, too high or low, when compared to White patients (23). All these studies emphasize that the clinical impact of BMI is complex and not consistent among different race/ethnic groups, and assessment of body composition, proportion of lean and fat mass, may be a better indicator of outcomes but more research is needed.

Our study has several limitations. Data was collected retrospectively as in all the other previous publications which examined the impact of race/ethnicity on cancer cachexia (6,7,14,18). The small sample size limits the power to identify significant differences in weight trajectory among racial/ethnic groups, and larger studies are needed. In addition, a selection bias may have occurred in the selection of patients for each racial/ethnic group, and data was extracted from a single tertiary oncology center with very few uninsured patients. Lack of insurance has been associated with weight loss in patients with lung cancer (19), and the worse outcomes can be explained by the limited access to care for patients delaying seeking treatment until their disease has advanced compared to insured patients (20). Although the stage of lung cancer was not collected, the inclusion criteria indicated only advanced disease and excluded early-stage disease. Despite these issues, this is to our knowledge the first investigation comparing the weight loss among different race/ethnic groups in patients with advanced lung cancer evaluated at Palliative Medicine consultation. Whether these findings are applicable to patients with different malignancies or diagnosis in other settings, is unknown.

Furthermore, our patients had a median 7% percentage weight loss at first consultation to Palliative Medicine, and only a few patients were getting treatments targeting their lack of appetite, suggesting under-treatment. Routine screening for weight changes including BMI, or ideally body composition (measuring muscle and fat mass) is recommended, and therapies directed at treating cancer cachexia should preferably start early in the weight loss process (1). Another point is that, despite being closely followed by a registered dietitian and palliative care specialists who were managing nutrition impact symptoms (24), our patients continued to lose an equivalent percentage of weight regardless of race/ethnicity emphasizing the difficulty in treating cancer related cachexia.

Conclusions

In summary, in palliative care patients with advanced lung cancer, percentage weight loss was not influenced by their self-reported race/ethnic identity. Patients who self-identified as Asian had significantly lower BMI, but still the percentage weight loss was like other racial/ethnic groups during treatment at a tertiary cancer center. Diagnostic criteria for cancer cachexia should accommodate race/ethnic variations in BMI but not percentage weight loss. Prospective investigations are needed to elucidate the relationship of self-identified race/ethnic classification and weight loss, ideally body composition, over time in patients with advanced cancer undergoing palliative care.

Acknowledgments

A preliminary version of this study was presented as an E-poster at the 19th World Congress of the European Association for Palliative Care, 29-31 May 2025, Helsinki, Finland.

Footnote

Reporting Checklist: The authors have completed the STROBE reporting checklist. Available at https://apm.amegroups.com/article/view/10.21037/apm-25-113/rc

Data Sharing Statement: Available at https://apm.amegroups.com/article/view/10.21037/apm-25-113/dss

Peer Review File: Available at https://apm.amegroups.com/article/view/10.21037/apm-25-113/prf

Funding: None.

Conflicts of Interest: All authors have completed the ICMJE uniform disclosure form (available at https://apm.amegroups.com/article/view/10.21037/apm-25-113/coif). E.B. serves as an unpaid editorial board member of Annals of Palliative Medicine from February 2025 to January 2027. R.D. serves as an unpaid editorial board member of Annals of Palliative Medicine from February 2024 to January 2026. The other authors have no conflicts of interest to declare.

Ethical Statement: The authors are accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved. The study was conducted in accordance with the Declaration of Helsinki and its subsequent amendments. The study was approved by the Institutional Review Board of the University of Texas MD Anderson Cancer Center (Protocol # 2023-0082) and individual consent for this retrospective analysis was waived.

Open Access Statement: This is an Open Access article distributed in accordance with the Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International License (CC BY-NC-ND 4.0), which permits the non-commercial replication and distribution of the article with the strict proviso that no changes or edits are made and the original work is properly cited (including links to both the formal publication through the relevant DOI and the license). See: https://creativecommons.org/licenses/by-nc-nd/4.0/.

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