Obese non-Hodgkin lymphoma patients tolerate full uncapped doses of chemotherapy with no increase in toxicity, and a similar survival to that seen in nonobese patients

Chemotherapy and Anticancer Drugs Adjustment in Obesity: A Narrative Review

BACKGROUND

Obese individuals have higher rates of cancer incidence and cancer- related mortality. The worse chemotherapy outcomes observed in this subset of patients are multifactorial, including the altered physiology in obesity and its impact on pharmacokinetics, the possible increased risk of underdosing, and treatment-related toxicity.

AIMS

The present review aimed to discuss recent data on physiology, providing just an overall perspective and pharmacokinetic alterations in obesity concerning chemotherapy. We also reviewed the controversies of dosing adjustment strategies in adult and pediatric patients, mainly addressing the use of actual total body weight and ideal body weight.

METHODS

This narrative review tried to provide the best evidence to support antineoplastic drug dosing strategies in children, adolescents, and adults.

RESULTS

Cardiovascular, hepatic, and renal alterations of obesity can affect the distribution, metabolism, and clearance of drugs. Anticancer drugs have a narrow therapeutic range, and variations in dosing may result in either toxicity or underdosing. Obese patients are underrepresented in clinical trials that focus on determining recommendations for chemotherapy dosing and administration in clinical practice. After considering associated comorbidities, the guidelines recommend that chemotherapy should be dosed according to body surface area (BSA) calculated with actual total body weight, not an estimate or ideal weight, especially when the intention of therapy is the cure.

CONCLUSION

The actual total body weight dosing appears to be a better approach to dosing anticancer drugs in both adults and children when aiming for curative results, showing no difference in toxicity and no limitation in treatment outcomes compared to adjusted doses.

Appropriate Systemic Therapy Dosing for Obese Adult Patients With Cancer: ASCO Guideline Update

PURPOSE

To provide recommendations for appropriate dosing of systemic antineoplastic agents in obese adults with cancer.

METHODS

A systematic review of the literature collected evidence regarding dosing of chemotherapy, immunotherapy, and targeted therapies in obese adults with cancer. PubMed and the Cochrane Library were searched for randomized controlled trials, meta-analyses, or cohort studies published from November 1, 2010, through March 27, 2020. ASCO convened an Expert Panel to review the evidence and formulate recommendations.

RESULTS

Sixty studies, primarily retrospective, were included in the review. Overall, the evidence supported previous findings that obese adult patients tolerate full, body-size-based dosing of chemotherapy as well as nonobese patients. Fewer studies have addressed the dosing of targeted therapies and immunotherapies in relation to safety and efficacy in obese patients.

RECOMMENDATIONS

The Panel continues to recommend that full, weight-based cytotoxic chemotherapy doses be used to treat obese adults with cancer. New to this version of the guideline, the Panel also recommends that full, approved doses of immunotherapy and targeted therapies be offered to obese adults with cancer. In the event of toxicity, the consensus of the Panel is that dose modifications of systemic antineoplastic therapies should be handled similarly for obese and nonobese patients. Important areas for future research include the impact of sarcopenia and other measures of body composition on optimal antineoplastic dosing, and more customized dosing based on pharmacokinetic or pharmacogenetic factors.Additional information is available at www.asco.org/supportive-care-guidelines.

Is there scope for better individualisation of anthracycline cancer chemotherapy?

Anthracyclines are used to treat solid and haematological cancers, particularly breast cancers, lymphomas and childhood cancers. Myelosuppression and cardiotoxicity are the primary toxicities that limit treatment duration and/or intensity. Cardiotoxicity, particularly heart failure, is a leading cause of morbidity and mortality in cancer survivors. Cumulative anthracycline dose is a significant predictor of cardiotoxicity risk, suggesting a role for anthracycline pharmacokinetic variability. Population pharmacokinetic modelling in children has shown that doxorubicin clearance in the very young is significantly lower than in older children, potentially contributing to their higher risk of cardiotoxicity. A model of doxorubicin clearance based on body surface area and age offers a patient-centred dose-adjustment strategy that may replace the current disparate initial-dose selection tools, providing a rational way to compensate for pharmacokinetic variability in children aged <7 years. Population pharmacokinetic models in adults have not adequately addressed older ages, obesity, hepatic and renal dysfunction, and potential drug-drug interactions to enable clinical application. Although candidate gene and genome-wide association studies have investigated relationships between genetic variability and anthracycline pharmacokinetics or clinical outcomes, there have been few clinically significant reproducible associations. Precision-dosing of anthracyclines is currently hindered by lack of clinically useful pharmacokinetic targets and models that predict cumulative anthracycline exposures. Combined with known risk factors for cardiotoxicity, the use of advanced echocardiography and biomarkers, future validated pharmacokinetic targets and predictive models could facilitate anthracycline precision dosing that truly maximises efficacy and provides individualised early intervention with cardioprotective therapies in patients at risk of cardiotoxicity.

The Prognostic Impact of Body Mass Index in Patients with Diffuse Large B-Cell Lymphoma: A Meta-Analysis

OBJECTIVE

Some studies on the relation between body mass index (BMI) and outcome of diffuse large B-cell lymphoma (DLBCL) remain controversial. We performed a meta-analysis to evaluate the overall survival (OS) and progression-free survival (PFS) of DLBCL in overweight (≥25 to <30 kg/m²), obese (≥30 kg/m²) and underweight (<18.5 kg/m²) individuals compared with normal weight patients (≥18.5 to <25 kg/m²).

METHODS

PubMed, Web of Science, EMBASE and the Cochrane Library databases were searched to identify relevant studies before February 20, 2020. The summary hazard ratio (HR) and 95% confidence interval (CI) were used for analyzing survival outcomes.

RESULTS

Fourteen articles involving 8,753 subjects were included. The pooled analysis indicated that OS of overweight group (HR = 0.86, 95% CI: 0.78-0.95, P = 0.002) was better than of normal weight group, but no association was found in obese patients (HR = 1.11, 95% CI: 0.81-1.53, P = 0.501). Similarly, obese and overweight status had no significant impact on PFS in DLBCL. Underweight patients had poorer OS (HR = 1.99, 95% CI: 1.45-2.74, P < 0.001) and PFS (HR = 1.78, 95% CI: 1.12-2.83, P = 0.014) compared with normal weight group.

CONCLUSION

Overweight patients have a better survival than normal weight patients, while underweight patients have a poorer survival in DLBCL.

Obesity is associated with an impaired survival in lymphoma patients undergoing autologous stem cell transplantation

Autologous hematopoietic stem cell transplantation (auto-HSCT) provides a potentially curative treatment option for relapsed and refractory lymphomas. Obesity displays an emerging epidemic risk factor for global mortality and is associated with an increased mortality in cancer patients. To date, the impact of obesity on the outcome of lymphoma patients undergoing auto-HSCT is understudied. We conducted a retrospective single-center study assessing 119 lymphoma patients who underwent auto-HSCT. Overall survival (OS) served as the primary endpoint whereas progression free survival (PFS), cumulative incidence of non-relapse related mortality (NRM) and cumulative incidence of relapse were analyzed as secondary endpoints. Obese patients (Body mass index, BMI≥30) had significantly lower OS (45.3% vs. 77.9%; p = 0.005) and PFS (29.8% vs. 67.2%; p<0.001) compared to non-obese patients at 48 months post-transplantation. The cumulative incidence of NRM displayed no significant differences while the cumulative incidence of relapse was significantly increased in patients with BMI≥30 (66.2% vs. 21.5%; p<0.001). Patients with a BMI<25 and overweight patients (BMI 25–30; 76.1% vs. 80.9%; p = 0.585), showed no significant difference in OS, whereas patients with BMI≥30 exhibited significant lower OS when compared to either of both groups (76.1% vs. 45.3%; p = .0.021 and 80.9% vs. 45.3%; p = 0.010). Furthermore, in a multivariate analysis, obesity was identified as an independent risk factor for death (Hazard ratio 2.231; 95% CI 1.024 to 4.860; p = 0.043). Further studies are needed to evaluate the reasons for the higher relapse rate causing higher mortality in obese patients.

Improved survival in overweight and obese patients with aggressive B-cell lymphoma treated with rituximab-containing chemotherapy for curative intent

The association between obesity and survival in non-Hodgkin lymphoma is unclear. Using the Ontario Cancer Registry we conducted a retrospective analysis of incident cases of aggressive-histology B-cell lymphoma treated with a rituximab-containing regimen with curative intent between 2008-2016. 6246 patients were included. On multivariable analysis the rate of all-cause mortality was lower for the overweight body mass index (BMI 25-29.9 kg/m²) (HR 0.85; 95%CI 0.77-0.95) and obese BMI (≥30 kg/m²) (HR 0.75; 95%CI 0.67-0.85) groups compared to the normal weight group (18.5-24.9 kg/m²). Binomial logistic regression analysis revealed a lower odds ratio (OR) of admission to hospital during treatment in the overweight (OR 0.84; 95%CI 0.75-0.95) compared to normal weight BMI group. In the largest cohort to date of aggressive-histology B-cell lymphoma patients treated with rituximab, increased BMI is associated with a survival advantage, and the magnitude of this effect increases from overweight to obese BMI.