Variability in determination of body weight used for dosing busulphan and cyclophosphamide in adult patients: results of an international survey

[Obesity and lung cancer: incidence and repercussions on epidemiology, pathology and treatments]

INTRODUCTION

Obesity and lung cancer are major public health problems. The purpose of this work is to review the data concerning this association.

METHOD

We report clinical and epidemiological data on obesity and discuss the impact on the incidence of lung cancer, as well as the safety and efficiency of anti-tumor treatments.

RESULTS

Obesity does not contribute to the occurrence of lung cancer, unlike other malignancies. Patients may be more likely to undergo treatment at lower risk. Regarding surgery, obesity makes anaesthesia more difficult, increases the operative duration but does not increase postoperative morbidity and mortality. Chemotherapy and radiotherapy seem to be administered according to the same criteria as patients with normal weight. Paradoxically, survival rates of lung cancer are better in obese patients as well after surgery than after non-surgical treatment.

CONCLUSION

Obesity is related to many neoplasms but not to lung cancer. Regarding long-term survival all treatments combined, it has a favorable effect: this is the "obesity paradox".

Chemotherapy dose adjustment for obese patients undergoing hematopoietic stem cell transplantation: a survey on behalf of the Acute Leukemia Working Party of the European Society for Blood and Marrow Transplantation

BACKGROUND

Appropriate chemotherapy dosing for obese patients with malignant diseases is a significant challenge because limiting chemotherapy doses in these patients may negatively influence outcome. There is a paucity of information addressing high-dose chemotherapy in obese patients undergoing hematopoietic stem cell transplantation (HSCT).

METHODS

The Acute Leukemia Working Party of the European Society for Blood and Marrow Transplantation (EBMT) designed an electronic survey to assess current practice of dose adjustment of chemotherapy in obese patients undergoing HSCT.

RESULTS

A total of 56 EBMT centers from 27 countries responded to the online survey. Overall, 45 centers declared that they routinely adjust chemotherapy doses for obese patients (80.5%), and only 11 (19.5%) declared they do not adjust dose. Among the former group, most used body mass index as the parameter for defining obesity (28 centers, 62%). The method for determining the weight for chemotherapy calculation was actual body weight (ABW) in 16 centers, ideal body weight (IBW) in 10 centers, IBW plus 25% of the difference between IBW and ABW in 16 centers, and other methods for the rest. Among centers that used dose adjustment, 44% also capped the dose at 2 m(2) for a chemotherapy dose based on body surface area (BSA), whereas 56% did not cap. Interestingly, most of the centers (9 of 11) that did not adjust dose for weight also did not cap the BSA at 2 m(2).

CONCLUSION

This EBMT survey revealed large diversity among transplant centers regarding dose-adjustment practice for high-dose conditioning chemotherapy. Our next step is to analyze outcomes of transplantation according to dose-adjustment practice and, subsequently, to formulate a methodology for future prospective studies.

Trimming the fat: obesity and hematopoietic cell transplantation

Obesity, increasing worldwide, is common in patients undergoing hematopoietic cell transplantation (HCT). This complex physiological state may alter the outcome of cancer therapies by many mechanisms including direct effects on pathogenesis, host responses to disease and altered pharmacology of chemotherapy. Obesity has been associated with multiple adverse health outcomes. Reports of obese patients undergoing HCT are challenging to interpret because of the heterogeneity of obesity definitions, underlying diseases, graft sources and chemotherapy regimens employed. Compared with normal-weight patients, it appears that obese patients undergoing allogeneic HCT have a higher risk of non-relapse mortality and inferior survival whereas those receiving autologous HCT appear to have equivalent outcomes. These findings are also difficult to interpret because there is no consistent standard for calculating chemotherapy dose in this group and future studies on specific regimens in this population are urgently needed. Patients who have undergone bariatric surgery may be at risk for unexpected events because of impaired nutritional state and altered pharmacokinetics of oral drugs. We recommend that future studies utilize more consistent and biologically relevant definitions of obesity and that the pharmacokinetics and pharmacodynamics of specific conditioning regimens be studied. Until more evidence is available, a rationale is presented for dosing based on adjusted body weight. Moreover, recommendations are provided to guide future research efforts based on more definitive measurements of body fat and its distribution available through modern quantitative imaging techniques using dual energy X-ray absorptiometry or magnetic resonance imaging scanning.

Appropriate chemotherapy dosing for obese adult patients with cancer: American Society of Clinical Oncology clinical practice guideline

PURPOSE

To provide recommendations for appropriate cytotoxic chemotherapy dosing for obese adult patients with cancer.

METHODS

The American Society of Clinical Oncology convened a Panel of experts in medical and gynecologic oncology, clinical pharmacology, pharmacokinetics and pharmacogenetics, and biostatistics and a patient representative. MEDLINE searches identified studies published in English between 1996 and 2010, and a systematic review of the literature was conducted. A majority of studies involved breast, ovarian, colon, and lung cancers. This guideline does not address dosing for novel targeted agents.

RESULTS

Practice pattern studies demonstrate that up to 40% of obese patients receive limited chemotherapy doses that are not based on actual body weight. Concerns about toxicity or overdosing in obese patients with cancer, based on the use of actual body weight, are unfounded.

RECOMMENDATIONS

The Panel recommends that full weight-based cytotoxic chemotherapy doses be used to treat obese patients with cancer, particularly when the goal of treatment is cure. There is no evidence that short- or long-term toxicity is increased among obese patients receiving full weight-based doses. Most data indicate that myelosuppression is the same or less pronounced among the obese than the non-obese who are administered full weight-based doses. Clinicians should respond to all treatment-related toxicities in obese patients in the same ways they do for non-obese patients. The use of fixed-dose chemotherapy is rarely justified, but the Panel does recommend fixed dosing for a few select agents. The Panel recommends further research into the role of pharmacokinetics and pharmacogenetics to guide appropriate dosing of obese patients with cancer.

Chemotherapy dosing strategies in the obese, elderly, and thin patient: results of a nationwide survey

PURPOSE

Determining the optimal starting dose of chemotherapy (CHT) presents a considerable challenge when using body-surface area (BSA)-based dosing, particularly in obese, elderly, or thin patients. We sought to document the range of approaches employed when administering CHT to these patients.

METHODS

A questionnaire was developed by a panel of oncologists and mailed to all members of the Medical Oncology Group of Australia.

RESULTS

From 315 oncologists, 188 responded (response rate 59.7%). BSA-based dosing is standard practice for 176 (97.2%) of the responding oncologists. In the adjuvant disease setting, 23 (12.7%) use ideal rather than actual body weight (BW) to calculate BSA, or choose whichever is less. When treating obese patients, only 6.1% of respondents routinely use actual BW. Of the remainder, 69.5% either cap the dose at 2 m(2) or use ideal BW. In underweight patients, 95% (n = 171) routinely calculate BSA using actual BW. Forty one respondents (22.7%) routinely reduce dose in the fit elderly.

CONCLUSION

This analysis of BSA-based CHT dosing methods demonstrates significant variability in practice. Based on evidence from adjuvant studies showing that actual BSA-based dosing is desirable, a substantial number of Australian patients are being underdosed. Further education, together with ongoing research, is required to optimize individualized dosing for efficacy and tolerability.

Effect of obesity on outcomes after autologous hematopoietic stem cell transplantation for multiple myeloma

Obesity has implications for chemotherapy dosing and selection of patients for therapy. Autologous hematopoietic stem cell transplant (AutoHCT) improves outcomes for patients with multiple myeloma, but optimal chemotherapy dosing for obese patients is poorly defined. We analyzed the outcomes of 1087 recipients of AutoHCT for myeloma reported to the CIBMTR between 1995 and 2003 who received high-dose melphalan conditioning, with or without total body irradiation (TBI). We categorized patients by body mass index (BMI) as normal, overweight, obese, or severely obese. There was no overall effect of BMI on progression-free survival (PFS), overall survival (OS), progression, or nonrelapse mortality (NRM). In patients receiving melphalan and TBI conditioning, obese and severely obese patients had superior PFS and OS compared with normal and overweight patients, but the clinical significance of this finding is unclear. More obese patients were more likely to receive a reduced dose of melphalan, but there was no evidence that melphalan or TBI dosing variability affected PFS. Therefore, current common strategies of dosing melphalan do not impair outcomes for obese patients, and obesity should not exclude patients from consideration of autologous transplantation. Further research is necessary to optimize dosing of both chemotherapy and radiation in obese patients.

Obesity does not preclude safe and effective myeloablative hematopoietic cell transplantation (HCT) for acute myelogenous leukemia (AML) in adults

The incidence of excessive adiposity is increasing worldwide, and is associated with numerous adverse health outcomes. We compared outcomes by body mass index (BMI) for adult patients with acute myelogenous leukemia (AML) who underwent autologous (auto, n = 373), related donor (RD, n = 2041), or unrelated donor (URD, n = 1801) allogeneic myeloablative hematopoietic cell transplantation (HCT) using bone marrow or peripheral blood stem cells reported to the Center for International Blood and Marrow Transplant Research (CIBMTR) from 1995 to 2004. Four weight groups by BMI (kg/m(2)) were defined: underweight <18 kg/m(2); normal 18-25 kg/m(2); overweight >25-30 kg/m(2); and obese >30 kg/m(2). Multivariable analysis referenced to the normal weight group showed an increased risk of death for underweight patients in the RD group (relative risk [RR], 1.92; 95% confidence interval [CI], 1.28-2.89; P = .002), but not in the URD group. There were no other differences in outcomes among the other weight groups within the other HCT groups. Overweight and obese patients enjoyed a modest decrease in relapse incidence, although this did not translate into a survival benefit. Small numbers of patients limit the ability to better characterize the adverse outcomes seen in the underweight RD but not the underweight URD allogeneic HCT patients. Obesity alone should not be considered a barrier to HCT.

Examining the safety and efficacy of a chemotherapy dosing method in Allogeneic Stem Cell Transplant patients of extreme body size

Background. There is no consensus on a universal dosing method for calculating high-dose chemotherapy in allogeneic Stem Cell Transplant (SCT) patients. The Metropolitan Life (Met-Life) Insurance Company’s weight—height tables have been used to determine body weight for chemotherapy dosing for SCT, however no formal study has been done to determine if the Met-Life weight— height tables can be used for chemotherapy dosing in SCT. We retrospectively studied the use of Met-Life weight—height tables for chemotherapy dosing in SCT. Our goal is to determine if patients with extremes of body size who had undergone an SCT and were dosed according to the Met-Life weight— height tables had an increase of Treatment Related Morbidity (TRM) or mortality or relapse.

Patients and Methods. Patients were grouped into three different treatment regimens, cyclophosphamide/TBI, busulphan/cyclophosphamide, and AraC/cyclophosphamide/TBI. Patients in each treatment regimen were further divided into five equal groups based on weight. Treatment related morbidity and mortality was evaluated by comparing the lowest and highest quintiles to the middle quintiles within each treatment regimen.

Result. Data from 262 patients was evaluated in this study. Overall, there was not an increase in TRM or mortality or in relapse in patients with extremes of body size.

Conclusion. The Met-Life weight—height tables could be used to dose patients undergoing allogeneic SCTs. Additional prospective studies would need to be done comparing other chemotherapy dosing methods with the Met-Life weight—height tables to further validate this conclusion.

The impact of obesity on the incidence and treatment of gynecologic cancers: a review

Sixty-five percent of the adult population in the United States is overweight and 30% of the population is obese. There is mounting evidence that obesity is a risk factor for gynecologic cancers and may also adversely impact survival. The objectives of this review were to systematically evaluate and discuss the impact of overweight and obesity on endometrial, ovarian, and cervical cancer incidence and to review the data on the impact of obesity on treatment of these same gynecologic cancers. A PUBMED literature search was performed to identify articles in the English language that focused on the impact of obesity on cancer incidence and treatment. References of identified articles were also used to find additional related articles. Obesity profoundly increases the incidence of endometrial cancer, predominantly through the effects of unopposed estrogen. Although the data are less compelling in ovarian and cervical cancer, obesity may modestly increase the incidence of premenopausal ovarian cancer and might potentially increase cervical cancer incidence, perhaps as a result of the impact on glandular cancers or decreased screening compliance. Obese women with cancer have decreased survival; this may be disease-specific, the result of comorbid illnesses, or response to treatment. Obese women have increased surgical complications, may also have increased radiation complications, and there is no current consensus regarding appropriate chemotherapy dosing in the obese patient. Obesity is a serious health problem with significant effects on the incidence and treatment of the gynecologic malignancies.

TARGET AUDIENCE

Obstetricians & Gynecologists, Family Physicians.

LEARNING OBJECTIVES

After completion of this article, the reader should be able to summarize the clear evidence that obesity is a risk factor for many cancers, including gynecologic malignancies; describe the role of unopposed estrogen in gynecologic cancers; and explain that obese women overall have a poorer survival rate when afflicted with cancer.

Cardiac toxicity of high-dose chemotherapy

Cardiac toxicity is an uncommon but potentially serious complication of high-dose (HD) chemotherapy and little is known about incidence, severity and underlying mechanisms. We have systematically reviewed the literature of the last 30 years to summarize and appraise the published evidence on cardiac toxicity associated with HD chemotherapy. HD cyclophosphamide-containing regimens have been most commonly associated with cardiac toxicity, with a progressively decreasing incidence over time. Dosage, application regimens and coadministration of other chemotherapeutic agents emerged as risk factors. While cardiac toxicity has been rarely associated with other cytotoxic drugs, an unexpected incidence of severe cardiotoxicity resulted from reduced-intensity conditioning regimens containing melphalan and fludarabine. Predictive value of cardiologic examination of patients is limited, and patients with a slight depression of cardiac performance could tolerate HD chemotherapy. Clinical examination, resting electrocardiography and dosage adjustment in overweight patients remain the mainstay of prevention, with bidimensional echocardiography (2D echo) for patients with a history of anthracycline exposure. Strategies to decrease the long-term negative impact of anthracycline administration on cardiac performance are being investigated. New 2D echo-based techniques and circulating markers of cardiac function hold promise for allowing identification of patients at high risk for and early diagnosis of cardiac toxicity.

Impact of obesity in the setting of high-dose chemotherapy

Obesity is a common and increasing problem affecting the developed world. Chemotherapy pharmacokinetics in the context of obesity demonstrate prolonged elimination time for several agents, but there is no consensus regarding optimal dosing schemes. Retrospective studies suggest differences in toxicity for obese adult patients but these data may be greatly impacted by chemotherapy dose adjustments. Outcome data from several studies have suggested that obese adult patients suffer poorer disease-free survival and overall survival, although this is not a uniform conclusion in all studies. Prospective studies of chemotherapy pharmacokinetics are needed to address the issue of optimal chemotherapy dosing in the obese population.

Successful transplant outcome in a morbidly obese patient with acute myeloblastic leukemia

We report a case of matched unrelated bone marrow transplant (BMT) in a morbidly obese patient with acute myeloblastic leukaemia. The challenges presented in the management of this case included the calculation of chemotherapy and radiotherapy doses and the acute presentation of obstructive sleep apnea. Despite these difficulties, an ultimately successful outcome was obtained, indicating that although associated with increased risk of peri-transplant morbidity, obesity need not represent a contraindication to BMT.

Obesity and autologous stem cell transplantation in acute myeloid leukemia

In the bone marrow transplant setting, several authors hypothesized that severely overweight patients are at increased risk of transplant-related toxicity, but different definitions of obesity, different body weight groupings and heterogeneous samples of patients were analyzed. To overcome these limitations, we retrospectively considered a homogeneous group of 54 patients (median age 36.5 years), with a diagnosis of de novo acute myeloid leukemia (AML), autografted in first complete remission (CR) with the Bu-Cy2 conditioning regimen, dosed on actual body weight. Patients were classified into three groups (obese, non-obese, underweight) using body mass index (BMI = kg/m(2)); for each group we analyzed transplant-related toxicity and mortality, overall survival and disease-free survival (OS/DFS). In spite of the relatively small number of patients, in our results high BMI appears a predictive factor for an increase of treatment-related toxicity and mortality. Moreover, 30 (55%) patients are currently alive in continuous CR, and after a median follow-up of 76.5 months (range 14-137) statistically significant differences in OS and DFS were detected between obese and non-obese groups (P = 0.012 and 0.021, respectively). Our study suggests that obesity may represent an independent risk factor for autograft in AML and further investigations are warranted.