Impact of body mass index on the efficacy of aromatase inhibitors in patients with metastatic breast cancer

Steatotic liver disease in metastatic breast cancer treated with endocrine therapy and CDK4/6 inhibitor

PURPOSE

In early-stage breast cancer, steatotic liver disease (SLD) is associated with increased recurrence, cardiovascular events, and non-cancer death. Endocrine therapy (ET) increases the risk of SLD. The impact of cyclin-dependent kinases 4/6 inhibitors (CDK4/6i) on SLD and prognostic association in metastatic breast cancer is unknown. We characterized the presence of SLD, risk factors, and treatment outcomes of SLD in metastatic HR+/HER2- breast cancer receiving CDK4/6i.

METHODS

This single institution, retrospective, cohort study included patients with metastatic HR+/HER2- breast cancer receiving first-line ET and CDK4/6i from January 2018 to June 2022. SLD was defined as a Liver Attenuation Index (LAI) > 25 HU on contrast-enhanced CT scans and/or > 10 HU on plain CT scans. Univariable binary-logistic regression was used to assess associations with SLD. Time to treatment failure (TTF) and overall survival (OS) were analyzed using Cox proportional hazards modeling.

RESULTS

Among 87 patients with a median age of 58 years and 65.5% postmenopausal, 50 (57.5%) had SLD at anytime (24 at baseline, 26 acquired). SLD at baseline was statistically associated with post-menopausal status. It was quantitatively but not statistically associated with age > 65, diabetes, smoking, and HER2-low. SLD at anytime was statistically significantly associated with longer TTF (median 470 vs 830.5 days, HR = 0.38, p < 0.001). No significant differences in OS or grade 3/4 adverse events were observed between groups.

CONCLUSION

This study demonstrated a high prevalence of SLD in this population, with SLD presence correlated with longer TTF. SLD may be an indicator of better outcomes in metastatic HR+/HER2- breast cancer patients treated with CDK4/6i.

The effect of BMI on survival outcome of breast cancer patients: a systematic review and meta-analysis

OBJECTIVE

The main goal of the present research is to explore the potential link of body mass index (BMI) with different survival metrics in breast cancer patients. Our aim is to offer the latest and most thorough meta-analysis, assessing the strength and reliability of the connection that BMI has with prognostic indicators in this disease.

PATIENTS AND METHODS

As of January 2024, we conducted a systematic literature search across PubMed, Embase, Web of Science, and the Cochrane Library databases. Our search aimed to identify studies examining BMI as an exposure factor, with breast cancer patients constituting the study population, and utilizing adjusted hazard ratio (HR) as the data type of interest.

RESULTS

The evidence synthesis incorporated a total of 61 eligible articles involving 201,006 patients. Being underweight posed a risk factor for overall survival (OS) in breast cancer patients compared to normal weight (HR 1.15, 95% CI 0.98-1.35; P = 0.08). Overweight or obesity, in comparison to normal weight, was a risk factor for OS (HR 1.18, 95% CI 1.14-1.23; P < 0.00001), disease-free survival (DFS) (HR 1.11, 95% CI 1.08-1.13; P < 0.00001), relapse-free survival (RFS) (HR 1.14, 95% CI 1.06-1.22; P = 0.03), and breast cancer-specific survival (BCSS) (HR 1.18, 95% CI 1.11-1.26; P < 0.00001), but not for progression-free survival (PFS) (HR 0.91, 95% CI 0.76-1.10; P = 0.33). Notably, in subgroup analyses, overweight patients achieved prolonged PFS (HR 0.80, 95% CI 0.64-0.99; P = 0.04), and compared to the obese population, the overweight cohort exhibited a significant difference in OS (HR 1.11, 95% CI 1.05-1.16; P < 0.00001) and DFS (HR 1.06, 95% CI 1.03-1.10; P = 0.0004), with a considerably stronger association. Furthermore, compared to HER- patients, HER + patients exhibited a greater predictive value for OS (HR 1.23, 95% CI 1.10-1.37; P = 0.0004), RFS (HR 1.30, 95% CI 1.03-1.64; P < 0.00001), and DFS (HR 1.10, 95% CI 1.03-1.17; P = 0.003).

CONCLUSIONS

The results of our meta-analysis reveal a notable association between BMI and various survival measures in breast cancer prognosis. These findings provide a solid basis for predicting breast cancer outcomes and implementing more effective therapeutic approaches.

Prognostic impact of body mass index on metastatic HER2-positive breast cancer survival

Background. The association between body mass index and prognosis in patients with HER2-positive metastatic breast cancer (mBC) is unclear. Purpose – the first purpose of our study was to determine whether BMI is an independent prognostic factor for progression-free survival (PFS) and overall survival (OS) in HER2-positive mBC patients. The second objective was to assess the mutual impact of baseline clinicopathological characteristics on survival outcomes. Materials and Methods. The study group included patients treated at the Sumy Regional Clinical Oncology Center. We considered the underweight patients if their BMI was <18.5 kg/m2, normal weight 18.5–24.9 kg/m2, overweight 25.0–29.9 kg/m2, and obese ≥ 30 kg/m2. The following formula was used for calculations: weight/height2 (kilograms/meter2). Information about the height, weight, and other clinicopathological characteristics of the patient at the time of the start of drug therapy was taken from the primary medical documentation. Pearson’s test and Chi2 test for categorical variables were used to compare baseline clinicopathological characteristics in groups with normal, overweight, and obesity. The Kaplan-Meier method was used to establish the medians of PFS and OS. Cox regression analysis assessed the mutual impact on the survival of various clinicopathological characteristics. The statistical significance threshold was considered P ≤0.05. Results. Seventy-eight patients with HER2-positive mBC were enrolled and categorized according to their BMI in normal weight, overweight, and obese groups. BMI had a different impact on PFS and OS. Median PFS was 14.9, 11.9, and 14.2 months for normal-weight, overweight, and obese patients, respectively. There is no statistically significant difference in PFS between groups (Р = 0.110). Multivariable regression analysis confirmed no impact of BMI on PFS. Nevertheless, metastases in bones and kidneys and the nuclear grade were statistically significant determinants of PFS. Median OS was 26.4, 28.8, and 37.9 months for normal-weight, overweight, and obese patients, respectively. BMI, kidney metastases, and nuclear grade were prognostically significant determinants of OS. Conclusions. BMI is an independent prognostic factor of OS in patients with HER2-positive mBC. Obesity is associated with better OS but does not impact PFS. Metastases in bones and kidneys and the nuclear grade can predict survival outcomes.

Visceral obesity and sarcopenia as predictors of efficacy and hematological toxicity in patients with metastatic breast cancer treated with CDK 4/6 inhibitors

PURPOSE

We aimed to investigate whether visceral adipose tissue (VAT), subcutaneous adipose tissue (SAT), and skeletal muscle area (SMA) index are predictive for efficacy and hematological toxicity in ER + HER2-metastatic breast cancer (BC) patients who received CDK 4/6 inhibitors.

METHODS

This retrospective cohort study analyzed 52 patients who were treated with CDK 4/6 inhibitors between January 2018 and February 2021. The values of VAT, SAT, SMA indices and hematological parameters were noted before the start, at the third and sixth months of this treatment. The skeletal muscle area (SMA) and adipose tissue measurements were calculated at the level of the third lumbar vertebra. A SMA-index value of <40 cm2/m2 was accepted as the threshold value for sarcopenia.

RESULTS

Patients with sarcopenia had a worse progression-free survival (PFS) compared to patients without sarcopenia (19.6 vs. 9.0 months, p = 0.005). Patients with a high-VAT-index had a better PFS (20.4 vs. 9.3 months, p = 0.033). Only the baseline low-SMA- index (HR: 3.89; 95% CI: 1.35-11.25, p = 0.012) and baseline low-VAT-index (HR: 2.15; 95% CI: 1.02-4.53, p = 0.042) had significantly related to poor PFS in univariate analyses. The low-SMA-index was the only independent factor associated with poor PFS (HR: 3.99; 95% CI: 1.38-11.54, p = 0.011). No relationship was observed between body composition parameters and grade 3-4 hematological toxicity.

CONCLUSION

The present study supported the significance of sarcopenia and low visceral adipose tissue as potential early indicators of poor PFS in patients treated with CDK 4/6 inhibitors.

The prognostic impact of BMI in patients with HR+/HER2- advanced breast cancer: a study of the SONABRE registry

PURPOSE

This study determines the prognostic impact of body mass index (BMI) in patients with hormone receptor-positive/human epidermal growth factor receptor-2-negative (HR+/HER2-) advanced (i.e., metastatic) breast cancer (ABC).

METHODS

All patients with HR+/HER2- ABC who received endocrine therapy +-a cyclin-dependent kinase 4/6 inhibitor as first-given systemic therapy in 2007-2020 in the Netherlands were identified from the Southeast Netherlands Advanced Breast Cancer (SONABRE) registry (NCT03577197). Patients were categorised as underweight (BMI: < 18.5 kg/m2), normal weight (18.5-24.9 kg/m2), overweight (25.0-29.9 kg/m2), or obese (≥ 30.0 kg/m2). Overall survival (OS) and progression-free survival (PFS) were compared between BMI classes using multivariable Cox regression analyses.

RESULTS

This study included 1456 patients, of whom 35 (2%) were underweight, 580 (40%) normal weight, 479 (33%) overweight, and 362 (25%) obese. No differences in OS were observed between normal weight patients and respectively overweight (HR 0.99; 95% CI 0.85-1.16; p = 0.93) and obese patients (HR 1.04; 95% CI 0.88-1.24; p = 0.62). However, the OS of underweight patients (HR 1.45; 95% CI 0.97-2.15; p = 0.07) tended to be worse than the OS of normal weight patients. When compared with normal weight patients, the PFS was similar in underweight (HR 1.05; 95% CI 0.73-1.51; p = 0.81), overweight (HR 0.90; 95% CI 0.79-1.03; p = 0.14), and obese patients (HR 0.88; 95% CI 0.76-1.02; p = 0.10).

CONCLUSION

In this study among 1456 patients with HR+/HER2- ABC, overweight and obesity were prevalent, whereas underweight was uncommon. When compared with normal weight, overweight and obesity were not associated with either OS or PFS. However, underweight seemed to be an adverse prognostic factor for OS.

The Challenges of Treating Patients with Breast Cancer and Obesity

Obesity is defined as a body mass index (BMI) of 30 kg/m2 or more and is associated with worse outcomes in patients with breast cancer, resulting in an increased incidence of breast cancer, recurrence, and death. The incidence of obesity is increasing, with almost half of all individuals in the United States classified as obese. Patients with obesity present with unique pharmacokinetics and physiology and are at increased risk of developing diabetes mellitus and cardiovascular disease, which leads to specific challenges when treating these patients. The aim of this review is to summarize the impact of obesity on the efficacy and toxicity of systemic therapies used for breast cancer patients, describe the molecular mechanisms through which obesity can affect systemic therapies, outline the existing American Society of Clinical Oncology (ASCO) guidelines for treating patients with cancer and obesity, and highlight additional clinical considerations for treating patients with obesity and breast cancer. We conclude that further research on the biological mechanisms underlying the obesity-breast cancer link may offer new treatment strategies, and clinicals trials that focus on the treatment and outcomes of patients with obesity and all stages of breast cancer are needed to inform future treatment guidelines.