Obesity and chemotherapy administration: between empiric and mathematic method review

Body adipose tissue depots and treatment outcomes for women with breast cancer: A systematic review

BACKGROUND & AIMS

Excessive adipose tissue is associated with poorer prognosis in women with breast cancer (BC). However, several body adiposity depots, such as visceral (VAT), subcutaneous (SAT), intermuscular (IMAT), and gluteofemoral adipose tissues (GFAT) may have heterogeneous metabolic roles and health effects in these patients. This systematic review aims to evaluate the impact of different body adipose tissue depots, assessed via computed tomography (CT), on treatment outcomes for women with BC. We hypothesize that distinct body adipose tissue depots may be associated differently with outcomes in patients with BC.

METHODS

A comprehensive bibliographical search was conducted using PubMed, Embase, Cochrane Library, Scopus, and Web of Science databases (until January 2024). The methodological quality of the included studies was assessed using the Newcastle-Ottawa Scale.

RESULTS

The final sample comprised 23 retrospective studies (n = 12,462), with fourteen presenting good quality. A lack of standardization in CT body adipose tissue depots measurement and outcome presentation precluded quantitative analysis. Furthermore, most included studies had heterogeneous clinical characteristics. Survival and treatment response were the most prevalent outcomes. VAT (n = 19) and SAT (n = 17) were the most frequently evaluated depots and their increase was associated with worse outcomes, mainly in terms of survival. IMAT (n = 4) presented contradictory findings and a higher GFAT (n = 1) was associated with better outcomes.

CONCLUSION

This systematic review found an association between increased VAT and SAT with worse outcomes in patients with BC. However, due to the heterogeneity of the included studies, further research with homogeneous methodologies is necessary to better understand the impact of body adipose tissue depots on treatment outcomes. Such knowledge could lead to improved care for this patient population.

Obesity and breast cancer prognosis: pre-diagnostic anthropometric measures in relation to patient, tumor, and treatment characteristics

PURPOSE

Examine the association between obesity and clinical outcomes in early breast cancer and assess if patient, tumor, and treatment characteristics modify such associations in Malmö Diet and Cancer Study patients (MDCS).

METHODS

The MDCS enrolled 17,035 Swedish women from 1991 to 1996. At enrollment, participants' body mass index (BMI), waist circumference and body fat percentage measures were collected. We identified all female MDCS participants with invasive breast cancer from 1991 to 2014. Follow-up began at breast cancer diagnosis and ended at breast cancer recurrence (BCR), death, emigration, or June 8, 2020. The World Health Organization guidelines were used to classify BMI, waist circumference, and body fat percentage into three categories of healthy weight, overweight, and obesity. We fit Cox regression models to compute adjusted hazard ratios (HRs) with 95% confidence intervals (CI) of BCR according to body composition. To evaluate effect measure modification, we stratified Cox models by patient, tumor, and treatment characteristics.

RESULTS

In total, 263 BCRs were diagnosed over 12,816 person-years among 1099 breast cancer patients with a median follow-up of 11.1 years. Obesity according to BMI (HR = 1.44 [95%CI 1.00-2.07]), waist circumference (HR = 1.31 [95%CI 0.98-1.77]), and body fat percentage (HR = 1.41 [95%CI 1.02-1.98]) was associated with increased risk of BCR compared with healthy weight. Obesity was stronger associated with BCR in patients with low socioeconomic position (HR = 2.55 [95%CI 1.08-6.02]), larger tumors > 20 mm (HR = 2.68 [95%CI 1.42-5.06]), estrogen-receptor-negative breast cancer (HR = 3.13 [95%CI 1.09-8.97]), and with adjuvant chemotherapy treatment (HR = 2.06 [95%CI 1.08-4.31]).

CONCLUSION

Higher pre-diagnostic BMI, waist circumference, and body fat percentage was associated with increased risk of BCR. The association between obesity and BCR appears dependent on patient, tumor, and treatment characteristics.

Obesity, cancer, and response to immune checkpoint inhibitors: Could the gut microbiota be the mechanistic link?

Immune checkpoint inhibitors (ICI) have deeply changed the therapeutic management of a broad spectrum of solid tumors. Recent observations showed that obese patients receiving ICIs might have better outcomes than those with normal weight, while obesity was historically associated with a worse prognosis in cancer patients. Of note, obesity is associated with alterations in the gut microbiome profile, which interacts with immune and inflammatory pathways, both at the systemic and intratumoral levels. As the influence of the gut microbiota on the response to ICI has been repeatedly reported, a specific gut microbiome profile in obese cancer patients may be involved in their better response to ICI. This review summarizes recent data on the interactions between obesity, gut microbiota, and ICIs. In addition, we highlight possible pathophysiological mechanisms supporting the hypothesis that gut microbiota could be one of the links between obesity and poor response to ICIs.

Adjuvant Dose Dense Chemotherapy in patients with obesity: short-term toxicities and breast cancer outcome

BACKGROUND

Dose dense adjuvant chemotherapy is associated with improved outcomes in breast cancer compared to standard dosing. Despite current guidelines recommending that chemotherapy is dosed according to actual body weight, reviews have shown patients with obesity often receive a capped chemotherapy dose. The latter is commonly undertaken as clinicians have concerns that adverse events are more frequent if full doses are administered. This study assessed surgical, radiotherapy and chemotherapy related adverse events between patients with and without obesity receiving dose dense adjuvant chemotherapy for breast cancer.

MATERIALS AND METHODS

A retrospective review of prospective collected data for patients receiving adjuvant chemotherapy from 30 April 2018 from a single institution was analyzed. Data collected included demographic data, height, weight, pathological information, comorbidities, surgical, radiotherapy chemotherapy treatment, and toxicity. Primary outcomes were surgical complications at 30 days, radiotherapy skin toxicity at 30 days and chemotherapy side-effects. Secondary outcomes were rates of recurrence and time to recurrence.

RESULTS

A total of 280 patients were included in the analysis: 55 obese and 225 nonobese. Obese status was associated with higher rates of grade >2 skin toxicity and this difference was significant after adjusting for age, comorbidity and radiotherapy field (P = .017). Obese status was not associated with higher rates of surgical or chemotherapy related adverse events. All patients regardless of obese status received adequate dose intensity with similar rates of recurrence and time to recurrence.

CONCLUSION

Patients with obesity who receive dose dense adjuvant chemotherapy do not experience higher rates of surgical or chemotherapy related adverse events although they do experience higher rates of grade >2 radiotherapy related skin toxicity. This supports the use of dose dense chemotherapy being based on actual body weight in patients with obesity.

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.

Antineoplastic dosing in overweight and obese cancer patients: an Associazione Italiana Oncologia Medica (AIOM)/Associazione Medici Diabetologi (AMD)/Società Italiana Endocrinologia (SIE)/Società Italiana Farmacologia (SIF) multidisciplinary consensus position paper

Most anticancer molecules are administered in body-size-based dosing schedules, bringing up unsolved issues regarding pharmacokinetic data in heavy patients. The worldwide spread of obesity has not been matched by improved methods and strategies for tailored drug dosage in this population. The weight or body surface area (BSA)-based approaches may fail to fully reflect the complexity of the anthropometric features besides obesity in cancer patients suffering from sarcopenia. Likewise, there is a lack of pharmacokinetic data on obese patients for the majority of chemotherapeutic agents as well as for new target drugs and immunotherapy. Therefore, although the available findings point to the role of dose intensity in cancer treatment, and support full weight-based dosing, empirical dose capping often occurs in clinical practice in order to avoid toxicity. Thus a panel of experts of the Associazione Italiana Oncologia Medica (AIOM), Associazione Medici Diabetologi (AMD), Società Italiana Endocrinologia (SIE), and Società Italiana Farmacologia (SIF), provides here a consensus statement for appropriate cytotoxic chemotherapy and new biological cancer drug dosing in obese patients.

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The worldwide spread of obesity is an emerging challenge also in cancer patients

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Weight or BSA-based approaches do not adequately address the critical issue of optimal dosing for cancer drugs under obesity

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Empirical dose capping is often employed in clinical practice to avoid toxicities among overweight and obese patients

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There is a lack of clinical and pharmacokinetic studies in this population

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Clinical practice recommendations should guide suitable dosing of cytotoxic and biological cancer drugs in obese patients

Impact of Obesity on Quality of Life, Psychological Distress, and Coping on Patients with Colon Cancer

BACKGROUND

Despite the causal relationship between obesity and colon cancer being firmly established, the effect of obesity on the course of cancer calls for further elucidation. The objective of this study was to assess differences in clinical-pathological and psychosocial variables between obese and nonobese individuals with colon cancer.

MATERIALS AND METHODS

This was a prospective, multicentric, observational study conducted from 2015-2018. The sample comprised patients with stage II-III, resected colon cancer about to initiate adjuvant chemotherapy with fluoropyrimidine in monotherapy or associated with oxaliplatin and grouped into nonobese (body mass index <30 kg/m² ) or obese (≥30 kg/m² ). Subjects completed questionnaires appraising quality of life (European Organization for Research and Treatment of Cancer Quality of Life Core questionnaire), coping (Mini-Mental Adjustment to Cancer), psychological distress (Brief Symptom Inventory 18), perceived social support (Multidimensional Scale of Perceived Social Support), personality (Big Five Inventory 10), and pain (Brief Pain Inventory). Toxicity, chemotherapy compliance, 12-month recurrence, and mortality rate data were recorded.

RESULTS

Seventy-nine of the 402 individuals recruited (19.7%) were obese. Obese subjects exhibited more comorbidities (≥2 comorbidities, 46.8% vs. 30.3%, p = .001) and expressed feeling slightly more postoperative pain (small size-effect). There was more depression, greater helplessness, less perceived social support from friends, and greater extraversion among the obese versus nonobese subjects (all p < .04). The nonobese group treated with fluoropyrimidine and oxaliplatin suffered more grade 3-4 hematological toxicity (p = .035), whereas the obese had higher rates of treatment withdrawal (17.7% vs. 7.7%, p = .033) and more recurrences (10.1% vs. 3.7%, p = .025). No differences in sociodemographic, quality of life, or 12-month survival variables were detected.

CONCLUSION

Obesity appears to affect how people confront cancer, as well as their tolerance to oncological treatment and relapse.

IMPLICATIONS FOR PRACTICE

Obesity is a causal factor and affects prognosis in colorectal cancer. Obese patients displayed more comorbidities, more pain after cancer surgery, worse coping, and more depression and perceived less social support than nonobese patients. Severe hematological toxicity was more frequent among nonobese patients, whereas rates of withdrawal from adjuvant chemotherapy were higher in the obese cohort, and during follow-up, obese patients presented greater 12-month recurrence rates. With the growing and maintained increase of obesity and the cancers associated with it, including colorectal cancer, the approach to these more fragile cases that have a worse prognosis must be adapted to improve outcomes.

Body surface area capping may not improve cytotoxic drugs tolerance

Capping body surface area (BSA) at 2 m² is a routine clinical practice. It aims at reducing toxicities in over 2 m² BSA patients. 455,502 computerized chemotherapy prescriptions made between 2011 and 2017 were taken from BPC software. Chemotherapy computerized order entry is created by a senior physician prescribers before patient consultation. Only prescriptions with dose calculation involving BSA were selected. 51,179 chemotherapy prescriptions were analyzed; corresponding to 7206 patients who received intravenous chemotherapy. The number of chemotherapy prescriptions in over 2 m² BSA patients was nearly the same in the hematology as in the oncology departments. But, 79.1% of prescriptions were capped at 2 m² in the oncology department contrary to 21.9% in the hematology department. Practices analysis showed more dose limitation in palliative situations in both departments. Unexpectedly, 6.53% of capped prescriptions were performed in patients with normal BMI. The patients who received capped doses of chemotherapy had neither fewer dose reductions due to toxicity nor deterioration of their general condition. Capping did not induce fewer dose reductions in patients with BSA greater than 2 m². Prospective studies in this population are needed to standardize chemotherapy administration in population with BSA > 2 m².

Modern pharmacological treatment of obese patients

There are many angles to consider in drug treatment of obese patients. On the one hand, some specific weight loss drugs are available, on the other, several drugs are associated with unintentional weight changes. When treating an obese patient for any given disease, several physiological changes may influence the pharmacokinetic properties of the drugs required. Thus, increased body weight may influence the efficacy and safety of some drug treatments. Even more complicated is the situation after weight reduction surgery. Due to the various changes to the gastrointestinal tract induced by the different surgical techniques used, and the dynamic changes in body composition thereafter, drug dosing has to be constantly reconsidered. Whereas all of these issues are of clinical importance, none of them have been investigated in the necessary depth and broadness to ensure safe and efficacious drug treatment of the massively obese patient. Individual considerations have to be based on comorbidities, concomitant medication, and on specific drug properties, for example, lipophilicity, volume of distribution, and metabolism. In this article we summarize the data available on different aspects of drug treatment in the obese patient with the hope of improving patient care.