Are medical oncologists biased in their treatment of the large woman with breast cancer?

Assessment of breast cancer chemotherapy dose reduction in an integrated healthcare delivery system

PURPOSE

Most cytotoxic drugs are dosed using body surface area (BSA), yet not all cancer patients receive the full BSA-determined dose. Prior work suggests that breast cancer patients who are obese are more likely to experience dose reduction than normal weight patients. However, the factors driving dose reduction remain unclear.

METHODS

In 452 women diagnosed with stage I-IIIA primary breast cancer at Kaiser Permanente Northern California, we evaluated the association between obesity and dose reduction, and further explored other factors in relation to dose reduction, including various sociodemographic characteristics, tumor characteristics, and comorbidities. Study participants were a part of the Pathways Study, diagnosed between 2006 and 2013 and treated with cyclophosphamide + doxorubicin, followed by paclitaxel (ACT). Dose reduction was assessed using first cycle dose proportion (FCDP) and average relative dose intensity (ARDI), a metric of dose intensity over the course of chemotherapy.

RESULTS

Overall, 8% of participants received a FCDP < 90% and 21.2% had an ARDI < 90%, with dose reduction increasing with body mass index. In adjusted logistic regression models, obese women had 4.1-fold higher odds of receiving an ARDI < 90% than normal weight women (95% CI: 1.9-8.9; p-trend = 0.0006). Increasing age was positively associated with an ADRI < 90%, as was the presence of comorbidity. Dose reduction was less common in later calendar years.

CONCLUSION

Results offer insight on factors associated with chemotherapy dosing for a common breast cancer regimen. Larger studies are required to evaluate relevance to other regimens, and further work will be needed to determine whether dose reductions impact outcomes in obese women.

Modifiable Barriers and Facilitators for Breast Cancer Care: A Thematic Analysis of Patient and Provider Perspectives

INTRODUCTION

We sought to examine patient and provider perspectives regarding modifiable contributors to breast cancer treatment and to assess perceptual alignment between these two groups.

MATERIALS

Participants were women≥18 y with stage 0-IV breast cancer who received all oncologic care in a single health system and physicians and advanced practice providers who provided medical, radiation, or surgical oncology care for breast cancer. All completed ∼45-min semistructured interviews that were recorded and transcribed verbatim. A 5-stage approach to thematic analysis was conducted, with emergent themes and exemplar quotes placed into clinical, psychological, social/logistical, financial, and lifestyle categories using a multilevel conceptual framework.

RESULTS

Eighteen patients (9 Black, 9 White, and median age 60 y) and 10 providers (6 physicians and 4 advanced practice providers) were interviewed from May to November 2018. Both patients and providers perceived suboptimal communication, parking and transportation, and competing family-caregiving responsibilities as modifiable barriers to care. Treatment costs were cited by patients as barriers that were inadequately addressed even with referrals to financial counselors, but providers did not raise the issue of cost unless prompted by patients and did not feel prepared to discuss the topic when it arose. Providers cited obesity as a barrier to treatment, a view not shared by patients.

CONCLUSIONS

Several modifiable factors were recognized by both patients and providers as either promoting or detracting from treatment receipt, but there was also significant incongruence and asymmetry. Alignment of provider and patient perceptions regarding contributors to guideline-concordant care receipt could mitigate disparities in breast cancer treatment and outcomes.

The influence of body mass index on the tolerability and effectiveness of full-weight-based paclitaxel chemotherapy in women with early-stage breast cancer

PURPOSE

To investigate the influence of body mass index (BMI) on the tolerability and effectiveness of full-weight-based paclitaxel chemotherapy in early breast cancer patients.

METHODS

Early-stage breast cancer patients who received (neo)adjuvant weekly paclitaxel 80 mg/m² chemotherapy were included in this retrospective study. Patients were divided into three groups based on their BMI: lean, overweight, and obese. Logistic regression was used to assess for association between BMI with administered relative dose intensity (RDI) < 85%. The occurrence of treatment modifications and the pathological response on neoadjuvant chemotherapy were compared between BMI categories.

RESULTS

Four hundred (400) patients were included in this study; 200 (50%) lean, 125 (31%) overweight, and 75 (19%) obese patients. The adjusted odds ratio to receive RDI < 85% for BMI was 1.02 (p value, .263). Treatment modifications occurred in 115 (58%), 82 (66%), and 52 (69%) patients in the respective BMI categories (p value = .132). Peripheral neuropathy was observed in 79 (40%), 58 (46%), and 41 (55%) patients in the lean, overweight, and obese group (p value = .069), whereas hematologic toxicity was observed in 31 (16%), 10 (8%), and 4 (5%) patients (p value = .025). Pathological complete response was observed in 22 (17%), 11 (14%), and 6 (13%) patients in the respective BMI categories (p value = .799).

CONCLUSION

BMI did not significantly influence the tolerability and effectiveness of full-weight-based paclitaxel chemotherapy. Therefore, the results of this study align with current guideline recommendations of using full-weight-based paclitaxel chemotherapy in obese patients.

Breast Cancer Risk Factors and Survival by Tumor Subtype: Pooled Analyses from the Breast Cancer Association Consortium

BACKGROUND

It is not known whether modifiable lifestyle factors that predict survival after invasive breast cancer differ by subtype.

METHODS

We analyzed data for 121,435 women diagnosed with breast cancer from 67 studies in the Breast Cancer Association Consortium with 16,890 deaths (8,554 breast cancer specific) over 10 years. Cox regression was used to estimate associations between risk factors and 10-year all-cause mortality and breast cancer-specific mortality overall, by estrogen receptor (ER) status, and by intrinsic-like subtype.

RESULTS

There was no evidence of heterogeneous associations between risk factors and mortality by subtype (P adj > 0.30). The strongest associations were between all-cause mortality and BMI ≥30 versus 18.5-25 kg/m2 [HR (95% confidence interval (CI), 1.19 (1.06-1.34)]; current versus never smoking [1.37 (1.27-1.47)], high versus low physical activity [0.43 (0.21-0.86)], age ≥30 years versus <20 years at first pregnancy [0.79 (0.72-0.86)]; >0-<5 years versus ≥10 years since last full-term birth [1.31 (1.11-1.55)]; ever versus never use of oral contraceptives [0.91 (0.87-0.96)]; ever versus never use of menopausal hormone therapy, including current estrogen-progestin therapy [0.61 (0.54-0.69)]. Similar associations with breast cancer mortality were weaker; for example, 1.11 (1.02-1.21) for current versus never smoking.

CONCLUSIONS

We confirm associations between modifiable lifestyle factors and 10-year all-cause mortality. There was no strong evidence that associations differed by ER status or intrinsic-like subtype.

IMPACT

Given the large dataset and lack of evidence that associations between modifiable risk factors and 10-year mortality differed by subtype, these associations could be cautiously used in prognostication models to inform patient-centered care.

Body mass index increases the lymph node metastasis risk of breast cancer: a dose-response meta-analysis with 52904 subjects from 20 cohort studies

Background

Since body mass index (BMI) is a convincing risk factor for breast cancer, it is speculated to be associated with lymph node metastasis. However, epidemiological studies are inconclusive. Therefore, this study was conducted to investigate the effect of BMI on the lymph node metastasis risk of breast cancer.

Methods

Cohort studies that evaluating BMI and lymph node metastasis in breast cancer were selected through various databases including PubMed, PubMed Central (PMC), Web of science, the China National Knowledge Infrastructure (CNKI), Chinese Scientific Journals (VIP) and Wanfang Data Knowledge Service Platform (WanFang) until November 30, 2019. The two-stage, random effect meta-analysis was performed to assess the dose-response relationship between BMI and lymph node metastasis risk. Between-study heterogeneity was assessed using I². Subgroup analysis was done to find possible sources of heterogeneity.

Results

We included a total of 20 studies enrolling 52,904 participants. The summary relative risk (RR) (1.10, 95%CI: 1.06–1.15) suggested a significant effect of BMI on the lymph node metastasis risk of breast cancer. The dose-response meta-analysis (RR = 1.01, 95%CI: 1.00–1.01) indicated a positive linear association between BMI and lymph node metastasis risk. For every 1 kg/m² increment of BMI, the risk of lymph node metastasis increased by 0.89%. In subgroup analyses, positive linear dose-response relationships between BMI and lymph node metastasis risk were observed among Asian, European, American, premenopausal, postmenopausal, study period less than 5 years, and more than 5 years groups. For every 1 kg/m² increment of BMI, the risk of lymph node metastasis increased by 0.99, 0.85, 0.61, 1.44, 1.45, 2.22, and 0.61%, respectively.

Conclusion

BMI significantly increases the lymph node metastasis risk of breast cancer as linear dose-response reaction. Further studies are needed to identify this association.

Obesity and mortality after locoregional breast cancer diagnosis

PURPOSE

Higher mortality after a breast cancer diagnosis has been observed among women who are obese. We investigated the relationships between body mass index (BMI) and all-cause or breast cancer-specific mortality after a diagnosis of locoregional breast cancer.

METHODS

Women diagnosed in 2004 with AJCC Stage I, II, or III breast cancer (n = 5394) were identified from a population-based National Program of Cancer Registries (NPCR) patterns of care study (POC-BP) drawing from registries in seven U.S. states. Differences in overall and breast cancer-specific mortality were investigated using Cox proportional hazards regression models adjusting for demographic and clinical covariates, including age- and stage-based subgroup analyses.

RESULTS

In women 70 or older, higher BMI was associated with lower overall mortality (HR for a 5 kg/m² difference in BMI = 0.85, 95% CI 0.75-0.95). There was no significant association between BMI and overall mortality for women under 70. BMI was not associated with breast cancer death in the full sample, but among women with Stage I disease; those in the highest BMI category had significantly higher breast cancer mortality (HR for BMI ≥ 35 kg/m² vs. 18.5-24.9 kg/m² = 4.74, 95% CI 1.78-12.59).

CONCLUSIONS

Contrary to our hypothesis, greater BMI was not associated with higher overall mortality. Among older women, BMI was inversely related to overall mortality, with a null association among younger women. Higher BMI was associated with breast cancer mortality among women with Stage I disease, but not among women with more advanced disease.

Hematological toxicity of carboplatin for gynecological cancer according to body mass index

PURPOSE

The aim of the present study was to analyze how patient weight affects the hematological toxicity of carboplatin and whether this toxicity is more prevalent in overweight patients.

METHODS

We performed a retrospective 2-year study of patients diagnosed with a gynecological cancer and whose treatment regimen contained carboplatin (AUC dose = 5 or 6) and paclitaxel (dose = 175 mg/m(2)) every 3 weeks (CP scheme). We recorded all severe hematological events (thrombocytopenia, neutropenia, and/or anemia grade III/IV) according to the CTCAE v4.03, as well as treatment modifications and the need for granulocyte colony-stimulating factors (G-CSF) and/or erythropoietin (EPO) or packed red blood cells (PRBC). Patients with a body mass index (BMI) ≥27 kg/m(2) were considered as overweight (OW) and those with a BMI <27 kg/m(2) were considered as normal weight (NW).

RESULTS

Fifty-two patients met the inclusion criteria (21 patients in the OW group, 31 patients in the NW group). The OW group showed a higher incidence of thrombocytopenia (95% confidence intervals (CI) 1.51-27.72; p < 0.02) and anemia (95% CI 1.06-33.63; p < 0.05). Moreover, this was reflected in a greater number of changes in the usual CP regimen (95% CI 2.19-44.32; p < 0.01). The need for G-CSF and/or EPO/PRBC was also significantly higher in the OW group (95% CI 1.08-12.16; p < 0.04).

CONCLUSIONS

Carboplatin dosing based on real weight in obese patients resulted in increased hematologic toxicity, mainly thrombocytopenia. Dose adjustment based on other descriptors of weight, such as adjusted weight, may be better tolerated by patients. However, future studies are needed to demonstrate not only better safety of carboplatin but also improved survival rates.

The impact of overweight and obesity on breast cancer: data from Switzerland, so far a country little affected by the current global obesity epidemic

This review presents results from the project "The Impact of Overweight/Obesity on Breast Cancer: data from Switzerland". Swiss data is interesting because the general female population is distinctive in two areas when compared to that of most other industrialized countries: Switzerland has comparatively low rates of overweight (22-23%) and obesity (7-8%) and has rather stable rates of overweight and obesity. The entire project comprised three major issues: (I) etiology of breast cancer (BC). There is a consistently shown association between obesity and postmenopausal BC risk in countries with high obesity prevalence rates in the literature. In our Swiss study group, however, we did not find higher rates of overweight and obesity in postmenopausal BC cases than in the general population. A possible explanation for this observation may be a curvilinear dose-response relationship between BMI and postmenopausal BC risk, so that an increased risk may only be observed in populations with a high prevalence of obese/very obese women; (II) tumor characteristics. BMI was significantly associated with tumor size; this applied not only to the cases where the tumor was found by self-detection, but also to lesions detected by radiological breast examinations. In addition, a higher BMI was positively correlated with advanced TNM stage, unfavorable grading and a higher St. Gallen risk score. No associations were observed between BMI and histological subtype, estrogen receptor status, HER2 status and triple negative BC; (III) patient compliance and persistence towards adjuvant BC therapy. Many studies found that the prognosis of overweight/obese BC patients was significantly lower than that of normal weight patients. However, failure of compliance and persistence towards therapy on the part of the patient is not a contributing factor for this observed unfavorable prognosis. In most therapy modes, patients with increasing BMI demonstrated greater motivation and perseverance towards the recommended treatment.

Randomized trial of a telephone-based weight loss intervention in postmenopausal women with breast cancer receiving letrozole: the LISA trial

PURPOSE

Obesity is associated with poor outcomes in women with operable breast cancer. Lifestyle interventions (LIs) that help women reduce their weight may improve outcomes.

PATIENTS AND METHODS

We conducted a multicenter randomized trial comparing mail-based delivery of general health information alone or combined with a 24-month standardized, telephone-based LI that included diet (500 to 1,000 kcal per day deficit) and physical activity (150 to 200 minutes of moderate-intensity physical activity per week) goals to achieve weight loss (up to 10%). Women receiving adjuvant letrozole for T1-3N0-3M0 breast cancer with a body mass index (BMI) ≥ 24 kg/m(2) were eligible. Weight was measured in the clinic, and self-report physical activity, quality-of-life (QOL), and diet questionnaires were completed. The primary outcome was disease-free survival. Accrual was terminated at 338 of 2,150 planned patients because of loss of funding.

RESULTS

Mean weight loss was significantly (P < .001) greater in the LI arm versus the comparison arm (4.3 v 0.6 kg or 5.3% v 0.7% at 6 months and 3.1 v 0.3 kg or 3.6% v 0.4% at 24 months) and occurred consistently across strata (BMI 24 to < 30 v ≥ 30 kg/m(2); prior v no prior adjuvant chemotherapy). Weight loss was greatest in those with higher baseline levels of moderate-intensity physical activity or improvement in QOL. Hospitalization rates and medical events were similar.

CONCLUSION

A telephone-based LI led to significant weight loss that was still evident at 24 months, without adverse effects on QOL, hospitalizations, or medical events. Adequately powered randomized trials with cancer end points are needed.

Adjuvant chemotherapy dosing in low-income women: the impact of Hispanic ethnicity and patient self-efficacy

Unwarranted breast cancer adjuvant chemotherapy dose reductions have been documented in black women, women of lower socioeconomic status, and those who are obese. No information on the quality of chemotherapy is available in Hispanic women. The purpose of this study was to characterize factors associated with first cycle chemotherapy dose selection in a multi-ethnic sample of low-income women receiving chemotherapy through the Breast and Cervical Cancer Prevention Treatment Program (BCCPT) and to investigate the impact of Hispanic ethnicity and patient self-efficacy on adjuvant chemotherapy dose selection. Survey and chemotherapy information were obtained from consenting participants enrolled in the California BCCPT. Analyses identified clinical and non-clinical factors associated with first cycle chemotherapy doses less than 90 % of expected doses. Of 552 patients who received chemotherapy, 397 (72 %) were eligible for inclusion. First cycle dose reductions were given to 14 % of the sample. In multivariate analyses, increasing body mass index and non-academic treatment site were associated with doses below 90 % of the expected doses. No other clinical or non-clinical factors, including ethnicity, were associated with first cycle doses selection. In this universally low-income sample, we identified no association between Hispanic ethnicity and other non-clinical patient factors, including patient self-efficacy, in chemotherapy dose selection. As seen in other studies, obesity was associated with systematic dose limits. The guidelines on chemotherapy dose selection in the obese may help address such dose reductions. A greater understanding of the association between type of treatment site and dose selection is warranted. Overall, access to adequate health care allows the vast majority of low-income women with breast cancer to receive high-quality breast cancer chemotherapy.

Obesity and mortality after breast cancer by race/ethnicity: The California Breast Cancer Survivorship Consortium

We investigated body size and survival by race/ethnicity in 11,351 breast cancer patients diagnosed from 1993 to 2007 with follow-up through 2009 by using data from questionnaires and the California Cancer Registry. We calculated hazard ratios and 95% confidence intervals from multivariable Cox proportional hazard model-estimated associations of body size (body mass index (BMI) (weight (kg)/height (m)(2)) and waist-hip ratio (WHR)) with breast cancer-specific and all-cause mortality. Among 2,744 ascertained deaths, 1,445 were related to breast cancer. Being underweight (BMI <18.5) was associated with increased risk of breast cancer mortality compared with being normal weight in non-Latina whites (hazard ratio (HR) = 1.91, 95% confidence interval (CI): 1.14, 3.20), whereas morbid obesity (BMI ≥ 40) was suggestive of increased risk (HR = 1.43, 95% CI: 0.84, 2.43). In Latinas, only the morbidly obese were at high risk of death (HR = 2.26, 95% CI: 1.23, 4.15). No BMI-mortality associations were apparent in African Americans and Asian Americans. High WHR (quartile 4 vs. quartile 1) was associated with breast cancer mortality in Asian Americans (HR = 2.21, 95% CI: 1.21, 4.03; P for trend = 0.01), whereas no associations were found in African Americans, Latinas, or non-Latina whites. For all-cause mortality, even stronger BMI and WHR associations were observed. The impact of obesity and body fat distribution on breast cancer patients' risk of death may vary across racial/ethnic groups.

Impact of chemotherapy-induced peripheral neuropathy on treatment delivery in nonmetastatic breast cancer

PURPOSE

To determine the incidence of dose-limiting (DL) chemotherapy-induced peripheral neuropathy (CIPN) events in clinical practice.

PATIENTS AND METHODS

This retrospective cohort study included 488 women who received docetaxel or paclitaxel. The primary outcome was a DL event (dose delay, dose reduction, or treatment discontinuation) attributed to CIPN (DL CIPN). The paired t test was used to test the difference in received cumulative dose and planned cumulative dose by dose reduction and treatment discontinuation status.

RESULTS

A total of 150 unique DL events occurred in 120 women (24.6%). More than one third (37.3%; n=56) of the events were attributed to CIPN. The 56 DL CIPN events occurred in 50 women (10.2%). DL CIPN incidence differed significantly by agent (docetaxel, 2.4%; n=five of 209; paclitaxel, 16.1%; n=45 of 279; P<.001). DL CIPN occurred in 24.5% and 14.4% of women who received paclitaxel 80 mg/m2 weekly for 12 cycles and 175 mg/m2 biweekly for four cycles, respectively (adjusted odds ratio, 2.11; 95% CI, 0.97 to 4.60; P=.06). The cumulative dose actually received was significantly lower than the planned cumulative dose among women who had a dose reduction or treatment termination attributed to CIPN (9.4% less; P<.001 and 28.4% less; P<.001, respectively).

CONCLUSION

Oncologists limited the dosing of chemotherapy because of CIPN in a significant proportion of paclitaxel recipients, most frequently in those who received a weekly regimen. Patients who had their dose reduced or discontinued received significantly less cumulative chemotherapy than planned. The implications of these DL CIPN events on treatment outcomes must be investigated.

Obesity in cancer survival

Although obesity is a well-known risk factor for several cancers, its role on cancer survival is poorly understood. We conducted a systematic literature review to assess the current evidence evaluating the impact of body adiposity on the prognosis of the three most common obesity-related cancers: prostate, colorectal, and breast. We included 33 studies of breast cancer, six studies of prostate cancer, and eight studies of colo-rectal cancer. We note that the evidence overrepresents breast cancer survivorship research and is sparse for prostate and colorectal cancers. Overall, most studies support a relationship between body adiposity and site-specific mortality or cancer progression. However, most of the research was not specifically designed to study these outcomes and, therefore, several methodological issues should be considered before integrating their results to draw conclusions. Further research is urgently warranted to assess the long-term impact of obesity among the growing population of cancer survivors.

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.

The two major epidemics of the twenty-first century: obesity and cancer

It is a well-known fact that severe obesity is associated with the metabolic syndrome, type 2 diabetes, cardiovascular disease, hypertension, and other diseases. Epidemiological studies have suggested that obesity is also associated with increased risk of several cancer types. The number of people who are suffering from severe obesity is growing, and clinical data suggest that severely obese patients belong to a unique population with regards to risk, efficacy of screening, and cancer treatment. This review will point out the potential mechanism linking obesity and cancer and will discuss several challenges in various treatment modalities of cancer in obese patients.

Pre-diagnosis body mass index and survival after breast cancer in the After Breast Cancer Pooling Project

Obese and underweight women who develop breast cancer may have poorer survival compared with normal-weight women. However, the optimal weight for best prognosis is still under study. We conducted a prospective investigation of pre-diagnosis body mass index (BMI) and mortality among 14,948 breast cancer patients in the After Breast Cancer Pooling Project. Breast cancer patients diagnosed from 1990 to 2006 with AJCC Stage I-III breast tumors were drawn from four prospective cohorts. Hazard ratios (HR) and 95% confidence intervals (CI) representing the associations of BMI categories (World Health Organization international classifications) with recurrence and mortality were estimated using delayed entry Cox proportional hazards models. Obese (30 to < 35 kg/m(2)), severely obese (35 to < 40 kg/m(2)), and morbidly obese (≥ 40 kg/m(2)) were examined. After a mean follow-up of 7.8 years, 2,140 deaths and 2,065 recurrences were documented. Both underweight (HR = 1.59; 95% CI: 1.18, 2.13) and morbidly obese women (HR = 1.81; 95% CI: 1.42, 2.32) had the greatest risk of overall mortality compared with normal weight (18.5-24.9 kg/m(2)) women. Severe obesity (HR = 1.09; 95% CI: 0.88, 1.36) and obesity (HR = 1.11; 95% CI: 0.97, 1.27) were related to small non-significant increased risks. Overweight (25.0-29.9 kg/m(2)) was not associated with any excess risk compared with normal weight. Similar associations were found for breast cancer death and non-breast cancer death but not recurrence. Women who were underweight and morbidly obese before breast cancer diagnosis were at the greatest risk of all-cause mortality. Morbidly obese women were also at increased risk of death from breast cancer. These results suggest that degree of obesity confers differential risk on survival.

Impact of body mass index on compliance and persistence to adjuvant breast cancer therapy

Several authors found that the prognosis of overweight and obese breast cancer (BC) patients was lower than that of normal weight patients. We present the first study which evaluates the impact of body mass index (BMI) on compliance (i.e. to start a recommended therapy) and persistence to adjuvant BC therapy. An unselected cohort of 766 patients (≤75 years) diagnosed from 1997 to 2009 was analyzed in relevance to the four adjuvant therapy modalities: (A) radiation, (B) chemotherapy, (C) therapy with trastuzumab, and (D) endocrine therapy. With respect to compliance, multivariate analyses calculated Odds ratios (ORs) >1 for increased BMI in all four therapy modalities, i.e. increased BMI had a positive influence on compliance. The results were significant for radiotherapy (OR,2.37;95%CI,1.45-3.88;p < 0.001) and endocrine therapy (OR,1.92;95%CI,1.21-3.04;p = 0.002) and showed a trend in chemotherapy (OR,1.42;95%CI,0.97-2.08;p = 0.063). Analyzing persistence, increasing BMI had ORs <1 for chemotherapy and therapy with trastuzumab, both not reaching statistical significance. For endocrine therapy, increasing BMI was a significant predictor for persistence (OR,1.35;95%CI,1.08-1.80;p = 0.042). Failure of compliance and persistence to adjuvant therapy does not pose a contributing factor for the observed unfavorable prognosis in overweight/obese BC patients. In most therapy modes, patients with increasing BMI demonstrated a higher motivation and perseverance to the recommended treatment.

The impact of obesity on receipt of adjuvant chemotherapy for breast cancer in the National Comprehensive Cancer Network (NCCN) centers

Disparities in the receipt of adjuvant chemotherapy for early stage breast cancer is an important factor influencing mortality. We investigated whether greater body mass index (BMI) decreases receipt of adjuvant chemotherapy among women with operable breast cancer. In the NCCN breast cancer outcomes database, we identified women aged ≤ 70 with newly diagnosed stage I, II, or III breast cancer between 1997 and 2007, for whom use of adjuvant chemotherapy was classified as either standard-of-care or discretionary based on their clinical characteristics. Body mass index was assessed in categories (<18.5 kg/m(2) [underweight], 18.5 to <25 kg/m(2) [normal], 25 to <30 kg/m(2) [overweight], 30-39 kg/m(2) [obese], ≥ 40 kg/m(2) [extreme obese]). Multivariable logistic regression analysis was used to examine the association between BMI and receipt of chemotherapy in each classification group. 9,527 women were eligible for the study; 40% normal weight or less; 31% overweight; 24% obese; and 5% extremely obese. In multivariable analysis, there was no significant association between BMI and receipt of chemotherapy in either classification group. Among women for whom chemotherapy would be considered standard-of-care, older age (P < 0.001), comorbidity (P < 0.001), and non-Hispanic black ethnicity (P = 0.002) were associated with a lower likelihood of receipt of chemotherapy; however, the effect of ethnicity was not modified by obesity. Among women treated for operable breast cancer in the NCCN centers, BMI had no impact on receipt of adjuvant chemotherapy and did not modify the lower likelihood of chemotherapy among non-Hispanic black patients. Further investigation is needed into other factors that contribute to patient disparities in the receipt of chemotherapy in major academic centers.

Effect of obesity on survival of women with breast cancer: systematic review and meta-analysis

Obesity is a risk factor for the development of new cases of breast cancer and also affects survival in women who have already been diagnosed with breast cancer. Early studies of obesity and breast cancer survival have been summarised in two meta-analyses, but the latest of these only included studies that recruited women diagnosed as recently as 1991. The primary aim of this study was to conduct a meta-analysis that included the more recent studies. A systematic search of MEDLINE, EMBASE and CINAHL was conducted to identify original data evaluating the effects of obesity on survival in newly diagnosed breast cancer patients. Adjusted hazard ratios (HR) from individual studies were pooled using a random effects model. A series of pre-specified sensitivity analyses were conducted on factors such as overall versus breast cancer survival and treatment versus observational cohort. The meta-analysis included 43 studies that enrolled women diagnosed with breast cancer between 1963 and 2005. Sample size ranged from 100 to 424168 (median 1192). The meta-analysis showed poorer survival among obese compared with non-obese women with breast cancer, which was similar for overall (HR = 1.33; 95% confidence interval (CI): 1.21, 1.47) and breast cancer specific survival (HR = 1.33; 95% CI: 1.19, 1.50). The survival differential varied only slightly, depending on whether body mass index (1.33; 1.21, 1.47) or waist-hip ratio (1.31; 1.08, 1.58) was used as the measure of obesity. There were larger differences by whether the woman was pre-menopausal (1.47) or post-menopausal (1.22); whether the cohort included women diagnosed before (1.31) or after 1995 (1.49); or whether the women were in a treatment (1.22) or observational cohort (1.36), but none of the differences were statistically significant. Women with breast cancer, who are obese, have poorer survival than women with breast cancer, who are not obese. However, no study has elucidated the causal mechanism and there is currently no evidence that weight loss after diagnosis improves survival. Consequently, there is currently no reason to place the additional burden of weight loss on women already burdened with a diagnosis of cancer. Further research should concentrate on assessing whether factors such as diabetes or type of chemotherapy modify the obesity effect and on understanding the causal mechanism, in particular the role of relative under-dosing.

Body mass index at the time of diagnosis and the risk of advanced stages and poorly differentiated cancers of the breast: findings from a case-series study

INTRODUCTION

Obesity is a risk factor for postmenopausal breast cancer and is independently associated with shorter disease-free and overall survival. Currently, in clinical settings, the combination of stage and grade of cancer at the initial presentation of the disease is the best prognostic indicator.

OBJECTIVE

To evaluate the association between body mass index (BMI) and risk of advanced stages and poorly differentiated grade of breast cancer.

DESIGN

A case-series study of women diagnosed with their first primary invasive breast cancer. Patients include a total of 831 women aged >or=40 years with a mean BMI of 29.6(± 6.6)  kg m(-2). Pathological, clinical and demographic data were retrieved from electronic medical records. Multinomial logistic regression analysis was preformed to estimate the risk of more advanced stages and poorly differentiated grade of cancer, adjusting for covariates.

RESULTS

Obese compared with normal weight women had an 80% increased risk of cancer with more advanced stages (III/IV) and poorly differentiated grade (odds ratio = 1.80, 95% confidence interval 1.13-2.86, P = 0.014). No significant increase in risk was observed for overweight women.

CONCLUSION

Obesity at the time of diagnosis of breast cancer is associated with more advanced stages and poorly differentiated grade of cancers.

Underweight and breast cancer recurrence and death: a report from the Korean Breast Cancer Society

PURPOSE

The association between body mass index and breast cancer outcome is controversial. Furthermore, the impact of underweight on breast cancer recurrence and death has not been adequately addressed.

PATIENTS AND METHODS

We investigated this issue using a large nationwide database of 24,698 Korean breast cancer patients. The association between body weight status and breast cancer recurrence was further explored using a single-institution database containing information on 4,345 patients.

RESULTS

The results from the nationwide database showed significantly lower overall survival (OS) and breast cancer-specific survival (BCSS) in underweight patients compared with survival in patients of normal weight after adjusting for known prognostic factors such as age, tumor size, lymph node metastasis, hormone receptor status, histologic grade, and lymphovascular invasion (hazard ratio [HR], 1.48; 95% CI, 1.15 to 1.90 for OS; HR, 1.49; 95% CI, 1.15 to 1.93 for BCSS), which were not observed in obese patients. In an analysis of recurrence data from the single institution, underweight women had a significantly higher risk of both distant metastasis and local recurrence of breast cancer (HR, 1.93; 95% CI, 1.04 to 3.58 and HR, 5.13; 95% CI, 2.66 to 9.90, respectively).

CONCLUSION

Our study suggests that underweight should be considered to be a high risk factor for death and recurrence after breast cancer surgery, especially in Asian breast cancer patients.

Relationship between obesity and pathologic response to neoadjuvant chemotherapy among women with operable breast cancer

PURPOSE

To understand the mechanism through which obesity in breast cancer patients is associated with poorer outcome, we evaluated body mass index (BMI) and response to neoadjuvant chemotherapy (NC) in women with operable breast cancer.

PATIENTS AND METHODS

From May 1990 to July 2004, 1,169 patients were diagnosed with invasive breast cancer at M. D. Anderson Cancer Center and received NC before surgery. Patients were categorized as obese (BMI >or= 30 kg/m(2)), overweight (BMI of 25 to < 30 kg/m(2)), or normal/underweight (BMI < 25 kg/m(2)). Logistic regression was used to examine associations between BMI and pathologic complete response (pCR). Breast cancer-specific, progression-free, and overall survival times were examined using the Kaplan-Meier method and Cox proportional hazards regression analysis. All statistical tests were two-sided.

RESULTS

Median age was 50 years; 30% of patients were obese, 32% were overweight, and 38% were normal or underweight. In multivariate analysis, there was no significant difference in pCR for obese compared with normal weight patients (odds ratio [OR] = 0.78; 95% CI, 0.49 to 1.26). Overweight and the combination of overweight and obese patients were significantly less likely to have a pCR (OR = 0.59; 95% CI, 0.37 to 0.95; and OR = 0.67; 95% CI, 0.45 to 0.99, respectively). Obese patients were more likely to have hormone-negative tumors (P < .01), stage III tumors (P < .01), and worse overall survival (P = .006) at a median follow-up time of 4.1 years.

CONCLUSION

Higher BMI was associated with worse pCR to NC. In addition, its association with worse overall survival suggests that greater attention should be focused on this risk factor to optimize the care of breast cancer patients.

Breast cancer adjuvant chemotherapy dosing in obese patients: dissemination of information from clinical trials to clinical practice

BACKGROUND

Substantial variation in adjuvant breast cancer chemotherapy dosing in obese women suggests that there is uncertainty about optimal practices. The purpose of this study was to investigate variations in dose determinations in clinical trial protocols and publications over the last 3 decades as potential sources of this uncertainty.

METHODS

The National Cancer Institute database was used to identify protocols of breast cancer adjuvant chemotherapy conducted by cooperative groups between 1970-2000, and these protocols were then obtained directly from the cooperative groups. Dose determinations were categorized in each protocol and in published reports from each clinical trial. Fisher exact tests were used to compare the proportions of protocols that used full weight-based doses over time.

RESULTS

Protocol-specified chemotherapy dosing was obtained for all of 44 eligible trials. A significant increase was identified in the use of full weight-based doses in the later time period compared with the earlier (P = .004; 2-sided Fisher exact test). A notable exception was 1 cooperative group that continues to require dose limitations for doxorubicin and cyclophosphamide in patients with a body surface area of more than 2.0 m(2). Regardless of publication date, published reports of clinical trials rarely provide information on use of full or limited weight-based doses.

CONCLUSIONS

Variations in dose determinations among clinical trial protocols and lack of information on use of full weight-based doses in most publications are 2 likely sources of variation in chemotherapy dosing in obese women. Developing consensus and disseminating information on optimal chemotherapy dosing will likely reduce such variation and may improve survival among obese patients with breast cancer.

Availability and utility of body mass index for population-based cancer surveillance

OBJECTIVE

To evaluate the availability of body height and weight data in the hospital medical record of cancer patients and discuss the utility of the findings to population-based cancer research and the surveillance of overweight and obesity in the United States.

METHODS

Medical records were reviewed for up to three measures of height and weight for a random sample of 1,739 patients diagnosed (2001-2003) with one of the 12 types of cancer and reported to the population-based Greater Bay Area Cancer Registry of Northern California.

RESULTS

About 84% of cancer patients had at least one value of height, 91% had at least one value of weight, and 83% had both values recorded in the medical record such that body mass index (BMI) could be computed. About 60% of height and weight values were recorded within 2 months of cancer diagnosis, with most values (71%) recorded after cancer diagnosis. The availability of BMI varied somewhat by race/ethnicity, cancer site, initial treatment, and hospital characteristics.

CONCLUSIONS

BMI may be sufficiently available to be included routinely in the population-based cancer registries, and, if so, would be useful for studies of cancer diagnoses and outcomes and permit nationwide surveillance of BMI in a large population-representative cohort of cancer patients.

Is obesity an independent prognosis factor in woman breast cancer?

BACKGROUND

Breast cancer and obesity represent important public health issues in most western countries. A number of studies found a negative prognosis effect of obesity or excess of weight in woman breast cancer. However, to date, this issue remains controversial. The objectives of this study were to confirm the prognosis role of obesity on a large cohort of patients and to investigate a potential independent effect.

MATERIALS AND METHODS

We constituted a cohort of 14,709 patients who were recruited and treated at the Curie Institute (Paris) from 1981 to 1999. These patients were followed prospectively for a first unilateral invasive breast cancer without distant metastasis. Obesity was defined by a Body Mass Index (BMI) above 30 kg/m(2) according to the World Health Organization recommendations.

RESULTS

Obese patients (8%) presented more extended tumors at diagnosis time suggesting a delayed breast cancer diagnosis. However, obesity appeared as a negative prognosis factor for several events in respectively univariate and multivariate survival analysis: metastasis recurrence (HR = 1.32[1.19-1.48]; HR = 1.12[1.00-1.26]), disease free interval (1.20[1.08-1.32]; 1.10[0.99-1.22]), overall survival (1.43[1.28-1.60]; 1.12[0.99-1.25]) and second primary cancer outcome (1.57[1.19-2.07]; 1.43[1.09-1.89]). Even if obese patients presented more advanced tumors at diagnosis time, multivariate analysis showed that there was a relevant independent effect. Other BMI codings, distinguishing overweight patients or using BMI as a continuous variable, showed a consistent correlation between BMI's value and prognosis effect. Interaction analysis revealed a more important obesity effect in the presence of tumor estrogen receptors and among limited extent tumors.

CONCLUSIONS

This survey confirms the prognosis role of obesity on one of the largest cohort by investigating several prognosis events. While independent obesity effect linked to hormonal disorders appeared consistent as obesity's mechanism, we stress that obesity prognosis effect was also related to breast cancer presentation at diagnosis time.

Receipt of appropriate primary breast cancer therapy and adjuvant therapy are not associated with obesity in older women with access to health care

PURPOSE

Many studies have reported body mass index (BMI) increases the risk of breast cancer recurrence and breast cancer-specific mortality. Few studies have reported or examined whether breast cancer treatment differs by BMI. The purpose of this study was to examine the association between BMI at breast cancer diagnosis and receipt of appropriate primary tumor therapy and adjuvant therapy.

METHODS

We identified 897 women age >or= 65 years diagnosed with stage I or II breast cancer from 1990 to 1999 at five health care organizations. We used medical records to confirm demographics, tumor characteristics, treatment, comorbid conditions, and to calculate BMI at diagnosis (< 25 kg/m(2), n = 328; 25 to < 30 kg/m(2), n = 305; 30 to < 35 kg/m(2), n = 188; >or= 35 kg/m(2), n = 76). We defined primary therapy based on National Guidelines as receiving breast-conserving surgery with radiation therapy and axillary node dissection, simple mastectomy with axillary node dissection, or modified radical mastectomy (73% overall); adjuvant therapy was defined as receipt of hormonal therapy, chemotherapy, or both (60% overall).

RESULTS

The median BMI was 26.7 kg/m(2) (range, 14.6 to 61.2). The proportion of women receiving primary therapy and adjuvant therapy was lowest for women less than 25 kg/m(2) (69% and 56%, respectively) and greatest for obese I (78% and 64%, respectively). There were no differences in receipt of primary or adjuvant treatment across BMI in univariate or multivariable models (after adjusting for age, stage, comorbidity, diagnosis year, and hormone receptor positivity).

CONCLUSION

Receipt of appropriate primary therapy and adjuvant therapy is not associated with BMI in older women with access to health care. Additional research in larger samples and more diverse settings is needed.

Obesity is not associated with increased myelosuppression in patients receiving chemotherapy for breast cancer

Audits of adjuvant chemotherapy for breast cancer have revealed that obese patients receive a lower relative dose intensity (RDI). However, interpretation of these studies is complicated by the variable use of cytokine growth factors, empiric dose capping and first cycle dose reductions. We have analysed the impact of obesity on RDI in a cohort of 662 patients that is not confounded by these factors. Patients were classified as overweight or obese on the basis of a body mass index (BMI)>or=25 kg/m2. The mean RDI in patients with BMI>or=25 kg/m2 was actually significantly greater than in those with BMI<25 kg/m2 (p=0.03). Overweight patients were less likely to experience cycle delays due to prolonged myelosuppression (p<0.001), particularly towards the end of the treatment course. We conclude that drug doses need not be reduced on the basis of obesity. Overall obese patients are in fact less likely to suffer haematological toxicity.

Effect of patient socioeconomic status and body mass index on the quality of breast cancer adjuvant chemotherapy

PURPOSE

The purpose of this study was to investigate the relationship between socioeconomic status (SES) and the use of intentionally reduced doses of chemotherapy in the adjuvant treatment of breast cancer.

PATIENTS AND METHODS

Patients with breast cancer treated with a standard chemotherapy regimen (n = 764) were enrolled in a prospective registry after signing informed consent. Detailed information was collected on patient, disease, and treatment, including chemotherapy doses. Zip code level data on median household income, proportion of people living below the poverty level, and educational attainment were obtained from the US Census. Doses for the first cycle of chemotherapy lower than 85% of standard were considered to be reduced. Univariate analyses and multivariate logistic regression were performed to identify factors associated with the use of reduced first cycle doses.

RESULTS

In univariate analysis, individual education attainment, zip code SES measures, body mass index, and geographic region were all significantly associated with receipt of intentionally reduced doses of chemotherapy. In multivariate analysis, controlling for geography, factors independently associated with reduced doses were obesity (odds ratio [OR], 2.47; 95% CI, 1.36 to 4.51), severe obesity (OR, 4.04; 95% CI, 1.46 to 11.19), and education less than high school (OR, 3.07; 95% CI, 1.57 to 5.99).

CONCLUSION

Social disparities in breast cancer outcomes may be in part the result of lower quality chemotherapy doses in the adjuvant treatment of breast cancer. Efforts to address such prescribing patterns may help reduce SES disparities in breast cancer survival.

Obesity and prognosis of breast cancer

Obesity has a complicated relationship to both breast cancer risk and the clinical behaviour of the established disease. It is suggested that obesity is associated with both an increased risk of developing breast cancer risk and worse prognosis after disease onset. In post-menopausal women, various measures of obesity such as body mass index, weight, weight gain and waist : hip ratio have all been positively associated with risk of developing breast cancer. In most but not all case-control and prospective cohort studies, an inverse relationship has been found between weight and breast cancer among pre-menopausal women. Some data suggest that adult weight gain and central obesity increase the risk of pre-menopausal breast cancer. Obesity at the time of diagnosis is thought to be significant as a poor prognostic factor. Obesity is associated with adverse outcomes in both pre- and post-menopausal women with breast cancer. Many cancer survivors seek ways to minimize the risk of recurrence and death because of breast cancer. Despite complex and at times controversial data, enough evidence is available at present to suggest that weight management should be a part of the strategy to prevent the occurrence, recurrence and death because of breast cancer. In this review the effect of obesity on the prognosis of breast cancer is examined in detail.

General and abdominal obesity and survival among young women with breast cancer

Among postmenopausal women, obesity is linked to increased risk of breast cancer and poorer subsequent survival. For premenopausal women, obesity may reduce incidence, but less is known about its effect on prognosis, particularly for abdominal obesity. This study investigated whether general or abdominal obesity at diagnosis influenced survival in a cohort of young women with breast cancer. A population-based follow-up study was conducted among 1,254 women ages 20 to 54 who were diagnosed with invasive breast cancer between 1990 and 1992 in Atlanta or New Jersey. Women were interviewed within several months of diagnosis and asked about their weight and height at age 20 and in the year before diagnosis. Study personnel did anthropometric measures at the interview. With 8 to 10 years of follow-up, all-cause mortality status was determined using the National Death Index (n = 290 deaths). Increased mortality was observed for women who were obese [body mass index (BMI), > or =30] at the time of interview compared with women of ideal weight [BMI, 18.5-24.9; stage- and income-adjusted hazard ratio (HR), 1.48; 95% confidence interval (95% CI), 1.09-2.01]. A similar result was seen for the highest versus lowest quartile of waist-to-hip ratio (HR, 1.52; 95% CI, 1.05-2.19). Strong associations with mortality were found for women who were obese at age 20 (HR, 2.49; 95% CI, 1.15-5.37) or who were overweight/obese (BMI, > or =25) at both age 20 and the time of interview (HR, 2.22; 95% CI, 1.45-3.40). This study provides evidence that breast cancer survival is reduced among younger women with general or abdominal obesity.

Obesity and survival in a cohort of predominantly Hispanic children with acute lymphoblastic leukemia

Acute lymphoblastic leukemia (ALL), the most common malignancy in children, constitutes 25% of all pediatric cancer. Childhood cancer patients who are obese at diagnosis represent a particular challenge for the oncologist. Obesity may complicate chemotherapy dose determination, and has been associated with decreased overall and event-free survival in a number of adult cancer patients, and more recently in pediatric patients. The purpose of the present study was to examine whether obesity at diagnosis was associated with decreased overall and event-free survival in a cohort of 322 predominantly Hispanic pediatric patients with B-precursor ALL. Obesity was classified as an age-standardized and sex-standardized body mass index z-score at or above the 95th percentile. Hazard ratios (HRs) for overall and event-free survival were assessed using Cox proportional hazards regression modeling. Obesity at diagnosis was not associated with decreased overall survival (HR = 1.40, 95% confidence interval = 0.69-2.87) or event-free survival (HR = 1.08, 95% confidence interval = 0.65-1.82) in the overall cohort or in either of the 2 age-at-diagnosis (2 to 9 y; 10 to 18 y) subgroups. Our finding of no obesity-related prognostic effect in the overall cohort and in the under 2 to 9-year age-at-diagnosis cohort was consistent with the previous large-scale study of ALL patients; the absence of a prognostic effect in the 10 to 18-year age-at-diagnosis cohort, however, conflicted with previous findings.

Obesity as a risk factor for development and poor prognosis of breast cancer

The evidence that obesity adversely affects women's health is overwhelming and indisputable. The risk of postmenopausal breast cancer increases with obesity; measured as weight gain, body mass index, waist-hip ratio or percent body fat. It is also established that obesity is associated with poor prognosis of breast cancer. This review examines in detail the possible mechanisms by which obesity causes poor prognosis of breast cancer such as estrogenic activity, advanced or more aggressive disease at diagnosis and high likelihood of both local and systemic treatment failure. After careful consideration of the available evidence, the author concludes that obesity contributes towards development and poor prognosis of breast cancer; therefore, weight management should be an integral part of any strategy to prevent and improve the outcome of breast cancer.

Post-diagnosis weight gain and breast cancer recurrence in women with early stage breast cancer

PURPOSE

To examine whether weight gain after diagnosis of breast cancer affects the risk of breast cancer recurrence.

PATIENT AND METHODS

Patients included 3215 women diagnosed with early stage breast cancer (Stage I >1 cm., II, and IIIA) who were enrolled either in an observational cohort of breast cancer survivors or were part of the comparison group of a dietary intervention trial to prevent breast cancer recurrence. We computed weight change from 1 year prior to diagnosis to study enrollment. Delayed entry Cox proportional hazards models were used to evaluate associations of categories of weight change with time to recurrence, controlling for known prognostic factors.

RESULTS

Neither moderate (5-10%) nor large (> 10%) weight gain (HR 0.8, 95% CI, 0.6-1.1; HR 0.9, 95% CI, 0.7-1.2, respectively) after breast cancer diagnosis was associated with an increased risk of breast cancer recurrence in the early years post-diagnosis (median time of 73.7 months from diagnosis).

CONCLUSION

Our research provides evidence that weight gain commonly seen in the first several years following a breast cancer diagnosis does not increase a woman's risk for breast cancer recurrence in the first 5-7 years post-diagnosis. However, this research does not address the effects of weight gain on overall survival or on the risk of other new cancers, other prognostic outcomes of concern to the breast cancer survivor.

Effects of obesity and race on prognosis in lymph node-negative, estrogen receptor-negative breast cancer

BACKGROUND

Several factors may contribute to poorer prognosis for obese breast cancer patients, including unfavorable disease features, the influence of fat on estrogen availability, co-morbidity, and socio-demographic factors. Both obesity and estrogen receptor negative (ER-) tumors are more prevalent in black women than in whites in North America. We evaluated obesity and race in relation to outcomes in women with ER-breast cancer.

METHODS

Among 4,077 women from National Surgical Adjuvant Breast and Bowel Project clinical trials for node-negative, ER-breast cancer, we evaluated disease-free survival (DFS) and its constituents (tumor recurrence, contralateral breast cancer (CBC), second primary cancers, deaths prior to these events) and mortality in relation to body mass index (BMI) and race, using statistical modeling to account for other prognostic factors.

RESULTS

Compared to those of normal weight (BMI< or =24.9), DFS hazard was greater for obese (BMI > or = 30) women [hazard ratio (HR)=1.16, 95% confidence interval (CI)=1.01-1.33]. Obesity did not increase recurrence hazard, but did influence CBC (HR=2.08, 95% CI=1.22-3.55 in postmenopausal women) and second cancers (HR=1.49, 95% CI=1.06-2.10). Mortality increased with obesity; when partitioned by likely cause, those with BMI > or = 35.0 had greater risk of non-breast cancer mortality (HR=1.86, 95% CI=1.21-2.84). Relative to whites and adjusted for BMI, black women had greater hazard for DFS (HR=1.17, 95% CI=1.00-1.38), CBC (HR=1.37, 95% CI=0.94-1.99), and non-breast cancer deaths (HR=2.10, 95% CI=1.45-3.03); risk for deaths likely due to breast cancer was closer to that in whites (HR=1.18; 95% CI=0.93-1.50).

CONCLUSIONS

For women with node-negative, ER-breast cancer from clinical trials, obesity did not increase recurrence risk, but was associated with greater risk for second cancers, CBC, and mortality, particularly non-breast cancer deaths. Less favorable prognosis for black women persists in clinical trials, and is in part attributable to non-breast cancer outcomes.

L-asparaginase as a marker of chemotherapy dose modification in children with acute lymphoblastic leukemia

BACKGROUND

The objective of the current study was to compare chemotherapy dose modifications in obese (a body mass index [BMI] > 95%) and nonobese (a BMI < or = 95%) pediatric patients with acute lymphoblastic leukemia (ALL).

METHODS

The study cohort was comprised of 199 pediatric patients diagnosed with ALL who were treated at 1 of 2 South Texas pediatric oncology centers between 1990-2000. The relative chemotherapy dose modification during the induction phase of chemotherapy was calculated as the ratio of 1) the actual administered dose of L-asparaginase and 2) the protocol-calculated dose of L-asparaginase. The extent to which the chemotherapy dose modification varied according to obesity status was assessed using stratified Student t tests and an ordinary least-squares regression analysis.

RESULTS

Obese ALL patients were found to exhibit a 7% decrease in the mean relative modification of L-asparaginase during induction chemotherapy compared with their nonobese counterparts. This finding was statistically significant (P = 0.009), even after adjustment for gender, age, ethnicity, and clinical institution.

CONCLUSIONS

To the authors' knowledge, the current study is the first published report of an obesity-associated chemotherapy dose modification in pediatric patients with ALL, the most common childhood malignancy. It will be important to examine whether these findings are consistent with those observed in future studies, and ultimately to assess the association between obesity-related dose modifications and long-term cancer outcomes.

Obesity and outcomes in premenopausal and postmenopausal breast cancer

PURPOSE

Obesity is associated with adverse outcomes in postmenopausal women with breast cancer. In premenopausal women, the association is less clear.

METHODS

A population-based sample of 1,360 Australian women with breast cancer before the age of 60 years, 47% diagnosed before age 40, and 74% premenopausal, was studied prospectively for a median of 5 years (range, 0.2-10.8 years). Obesity was defined as a body mass index of > or =30 kg/m2. The hazard ratio (HR) for adverse clinical outcome associated with obesity was estimated using Cox proportional hazard survival models.

RESULTS

Obesity increased with age (P < 0.001) and was associated with increased breast cancer recurrence (P = 0.02) and death (P = 0.06), larger tumors (P = 0.002), and more involved axillary nodes (P = 0.003) but not with hormone receptor status (P > or = 0.6) or with first cycle adjuvant chemotherapy dose reductions (P = 0.1). Adjusting for number of axillary nodes, age at diagnosis, tumor size, grade, and hormone receptor status, obese women of all ages were more likely than nonobese women to have disease recurrence [HR, 1.57; 95% confidence interval (95% CI), 1.11-2.22; P = 0.02] and to die from any cause during follow-up (HR, 1.56; 95% CI, 1.01-2.40; P = 0.05). In premenopausal women, the adjusted HRs were 1.50 (95% CI, 1.00-2.26; P = 0.06) and 1.71 (95% CI, 1.05-2.77; P = 0.04), respectively.

CONCLUSIONS

Obesity is independently associated with poorer outcomes in premenopausal women, as it is in postmenopausal women, and this is not entirely explained by differences in tumor size or nodal status. Given the high and increasing prevalence of obesity in western countries, more research on improving the treatment of obese breast cancer patients is warranted.

Factors that affect breast cancer treatment: underserved and minority populations

Breast cancer treatment in underserved populations continues to deviate from established guidelines. Significant barriers persist at the system, physician, and patient levels that ultimately may affect survival adversely. Successful strategies to reduce the disparities must be developed to improve outcomes in this population of women.