Abstract P2-16-01: Relationship between overall survival and surrogate measures in patients with metastatic breast cancer treated with chemotherapy

Background: While metastatic breast cancer (MBC) is considered an incurable disease, nearly one-fifth of patients live longer than five years following diagnosis. In an effort to identify novel agents earlier, surrogate end points of overall survival (OS) such as response or progression are often employed in randomized controlled trials (RCTs). The goal of this analysis is to evaluate patterns of outcome reporting and the relationship of OS with surrogate measures in RCTs of patients with MBC.

Methods: The analysis was based on data from a systematic review of patients with MBC evaluating the clinical impact of chemotherapy intensity on survival. Reports of phase 2-3 RCTs published between 1990-2013 comparing more intense chemotherapy regimens (higher dose intensity or use of additional agents) with less intense were identified. For each RCT, clinical, treatment, demographic and outcome data were extracted. Outcomes evaluated included OS, progression free survival (PFS), and time to progression (TTP) with a focus on median survival and hazard ratios (HRs) as measures of treatment effect. Survival post progression (SPP) was calculated as the difference between median survival and median progression free time. The relations between various outcome measures were estimated utilizing weighted Pearson correlation coefficient (CORR) adjusted by Fisher's transformation. Weights were assigned proportionally to the sample size of individual RCTs.

Results: The review identified 70 eligible RCTs including 15,043 patients with MBC. Average median OS, PFS, and TTP were 19.2, 6.9, and 8.1 months reported in 96%, 60%, and 43% of studies, respectively. Progression could be determined in 66 studies, while 6 RCTs provided both outcomes. TTP was more often utilized in earlier studies (65% in 1990-2000, 35% in 2001-2008, and 33% in 2009-2013) and it was superseded by PFS in later years (20%, 70% and 81%, respectively). Only 37%, 33%, and 11% of RCTs reported HRs for OS, PFS, and TTP, respectively. HRs were more often available in recent publications (20% in 1990-2000, 22% in 2001-2008, 63% in 2009-2013 provided HR for OS). The correlation between reported HR and HR estimated by the ratio of arm-specific median survival times was high for OS (CORR=0.87, 95%CI: 0.73-0.94) and TTP (CORR=0.92, 95%CI: 0.61-0.99) and slightly lower for PFS (CORR=0.72, 95%CI: 0.44-0.87). The relationship between OS and surrogate measures (PFS, TTP) was weaker. The correlation between HR for OS and PFS was 0.49 (95%CI: 0.21-0.69) and for OS and TTP it was 0.26 (95%CI: -0.13-0.58). Survival time following progression was dependent on treatment type and was longer in less intense arms than more intense (mean SPP: 12.4 months vs. 11.4 months, P=0.0155).

Conclusions: In RCTs of patients with MBC treated with chemotherapy, when HR is not reported and if necessary statistical conditions are met, the HR approximated by ratio of median survival times may be a suitable proxy estimate. In agreement with other reports, neither PFS nor TTP are acceptable surrogate outcomes for OS in MBC, as survival following progression may be substantial. In these patients, crossover and post-trial treatments may influence the relationship between OS and surrogate measures.

Citation Format: Culakova E, Poniewierski MS, Crawford J, Dale DC, Lyman GH. Relationship between overall survival and surrogate measures in patients with metastatic breast cancer treated with chemotherapy [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P2-16-01.

Abstract P3-15-08: A multicenter observational study to investigate the relationship between physician-assessed febrile neutropenia (FN) risk and prediction model FN or SN (severe neutropenia) risk in patients with breast cancer

Background: A prediction model was previously developed to estimate the risk of SN or FN during the first cycle of chemotherapy, taking into account both the myelotoxicity of the chemotherapy regimen and the interplay of specific tumor and patient characteristics (Lyman, 2011). This model may potentially be useful for predicting which patients are at greatest risk for developing neutropenic complications, particularly among those patients receiving intermediate FN risk chemotherapy regimens, where the influence of patient characteristics becomes a critical consideration. To assess the clinical utility of this model, physicians assessed FN risk in patients with non-myeloid malignancies, and then physician-assessed FN risk was compared to prediction model risk.

Methods: This was a prospective, multicenter, observational study (124 community-based oncologists, 944 patients). Analysis of a breast cancer subgroup (93 oncologists, 364 patients) is reported here. Patients were eligible if they were: ≥18 years old, newly diagnosed, and candidates for initiating a new course of chemotherapy using an NCCN intermediate (10-20%) FN risk chemotherapy regimen. Oncologists entered clinical data about the patient into the model; they also made a clinical prediction of FN risk. Oncologists were blinded to both the data elements collected by the model and the risk predicted by the model. Data were only collected until the chemotherapy order was written; no outcome data were collected. The primary objective was to investigate the relationship between physician-assessed FN risk and prediction model SN or FN risk. As an exploratory endpoint, physicians were asked to estimate FN risk on the same set of four hypothetical case studies with varying FN risk factors. The correlation between risk probability scores was estimated as well as a 95% confidence interval accounting for intra-physician correlation. A smooth spline curve was fit to show the average relationship between physician-assessed and prediction model risk probability scores.

Results: Most patients were planning to receive TC (54%) and most had stage I-II disease (71%). Median (min, max) age was 58 years (23, 83). Physician-assessed FN risk correlated weakly with prediction model FN or SN risk: correlation 0.166 (95% CI: 0.027, 0.298). There was wide variability among all 124 physicians in their assessment of FN risk for the four case studies (Q1, Q3 case study 1: 20%, 40%; case study 2: 10%, 18%; case study 3: 20%, 40%; case study 4: 25%, 60%).

Conclusions: This study suggests that community oncologists would benefit from the use of an automated system for assessing FN risk among those receiving intermediate risk chemotherapy regimens. Such a system would help oncologists identify the patients who would benefit most from clinical intervention and help improve practice efficiency and quality of care.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P3-15-08.

Thyroid storm presenting as congestive heart failure and protein-S deficiency-induced biventricular and internal jugular venous thrombii

The thyroid storm is a medical emergency characterized by decompensation of one or more organ systems. Associated cardiac involvement carries poor prognosis. Early recognition and appropriate management of life-threatening thyrotoxicosis is vital to prevent the high morbidity and mortality that may accompany this disorder. We report a young lady presenting with thyroid storm presenting as acute heart failure with biventricular and bilateral internal jugular venous thrombi. In addition, she also had thyrotoxicosis-induced transient protein-S deficiency which recovered following remission.

The impact of the granulocyte colony-stimulating factor on chemotherapy dose intensity and cancer survival: a systematic review and meta-analysis of randomized controlled trials

BACKGROUND

The granulocyte colony-stimulating factor (G-CSF) is utilized to reduce neutropenic complications in patients receiving cancer chemotherapy. This study represents a systematic review and evidence summary of the impact of G-CSF support on chemotherapy dose intensity and overall mortality.

MATERIALS AND METHODS

All randomized controlled trials (RCTs) comparing chemotherapy with or without G-CSF support and reporting all-cause mortality with at least 2 years of follow-up were sought. Dual-blind data abstraction of disease, treatment, patient and outcome study results with conflict resolution by third party was carried out.

RESULTS

The search revealed 61 randomized comparisons of chemotherapy with or without initial G-CSF support. Death was reported in 4251 patients randomized to G-CSFs and in 5188 controls. Relative risk (RR) with G-CSF support for all-cause mortality was 0.93 (95% confidence interval: 0.90-0.96; P < 0.001). RR for mortality varied by intended chemotherapy dose and schedule: same dose and schedule (RR = 0.96; P = 0.060), dose dense (RR = 0.89; P < 0.001), dose escalation (RR = 0.92; P = 0.019) and drug substitution or addition (RR = 0.94; P = 0.003). Greater RR reduction was observed among studies with longer follow-up (P = 0.02), where treatment was for curative intent (RR = 0.91; P < 0.001), and where survival was the primary outcome (RR = 0.91; P < 0.001).

CONCLUSIONS

All-cause mortality is reduced in patients receiving chemotherapy with primary G-CSF support. The greatest impact was observed in RCTs in patients receiving dose-dense schedules.

Abstract P1-15-04: The relationship of relative dose intensity and supportive care to febrile neutropenia rates in patients with early stage breast cancer receiving chemotherapy: a prospective cohort study of chemotherapy-associated toxicity

Background: Febrile neutropenia (FN) represents a major dose-limiting toxicity of cancer chemotherapy resulting in considerable morbidity, mortality, and cost. Patients have the highest risk of the initial neutropenic event in cycle 1 when most patients receive full dose chemotherapy. This study evaluates time course of neutropenic events in patients receiving chemotherapy for early-stage breast cancer (ESBC) and supportive care interventions that modify FN risk in ESBC patients treated in actual oncology practice.

Methods: A prospective cohort study of adult cancer patients with solid tumors or lymphoma starting a chemotherapy regimen was conducted at 115 U.S. sites. Toxicities associated with chemotherapy were recorded in up to 4 cycles including severe neutropenia (SN), FN, and infection. Documented clinical interventions included reductions in chemotherapy relative dose intensity (RDI), the use of colony-stimulating factors (CSFs), and antibiotics.

Results: A total of 1202 ESBC patients starting chemotherapy were analyzed, of which 1154, 1099, and 896 reached the midcycle of cycles 2, 3, and 4, respectively. While the majority of neutropenic and infection events occurred in cycle 1, decreasing rates of FN and infection in later cycles correlated with increasing reductions in dose intensity and increased use of CSFs and antibiotics.

Acute myeloid leukemia or myelodysplastic syndrome (AML/MDS) and overall mortality with chemotherapy (CT) and granulocyte colony-stimulating factor (G-CSF): A meta-analysis of randomized controlled trials (RCTs)

9524

Background: To evaluate the risk of AML/MDS and overall mortality in patients receiving CT ± G-CSF, a meta-analysis of RCTs were conducted. Methods: Electronic databases searched through August 2008 identified 3,794 articles for initial screening. Eligibility included RCTs of solid tumor or lymphoma patients randomized to CT ± primary G-CSF support, ≥2 years follow-up and reporting AML/MDS or all second malignancies. Pre-specified study categories included: a)same dose/schedule, b)dose-dense or c)dose-escalated CT. Primary outcomes were AML/MDS and mortality. Dual blinded data extraction was performed. Relative risk (RR) and absolute risk difference (ARD) were estimated by Mantel-Haenszel. Results: Median follow-up was 54 months. 12,642 patients were randomized to CT ± primary G-CSF support. Second malignancies were reported in 3.3% and 3.2% with and without G-CSF, respectively (P=.942). RR for AML/MDS with CT+G-CSF compared to control was 1.92 [P=.006] with ARD increase of 0.4% [P=.008]. RR for AML/MDS in study categories to receive the same, dose-dense or dose-escalated CT+G-CSF were 1.95 [P=.346], 1.20 [P=.666] and 2.47 [P=.006], respectively. RR for mortality with CT+G-CSF was 0.898 [P<.0001] with ARD decrease of 3.3% [P<.0001]. RR for mortality in study categories to receive the same, dose-dense or dose-escalated CT+G-CSF were 0.95 [P=.140], 0.84 [P<.001] and 0.91 [P=.019], respectively. Delivered relative dose intensities (RDI) were 1.18, 1.46 and 1.23 in studies planned to receive the same, dose-dense or dose-escalated CT, respectively. A significant association was observed between delivered RDI and reduced mortality [P=.013]. No differences in estimates of AML/MDS or mortality were observed between industry and non-industry-funded studies. Conclusions: Risk of AML/MDS is increased with dose escalated CT+G-CSF. Nevertheless, CT+G-CSF is associated with greater reductions in overall mortality. Dose-dense regimens are associated with the greatest RR reduction in mortality and lowest risk of AML/MDS. Further research is needed to differentiate any impact of G-CSF on the risk of AML/MDS from that due to increased CT intensity.

[Table: see text]

A validated risk model for early neutropenic events in older cancer patients receiving systemic chemotherapy

9036

Background: A prospective, nationwide study was undertaken to develop and validate a risk model for early neutropenic events (NE) in older cancer patients undergoing chemotherapy. Methods: 1,386 patients =65 years of age with lung, breast, colorectal, ovarian cancer or lymphoma were prospectively registered at 117 randomly selected sites. Data on up to 4 cycles were collected upon initiation of chemotherapy. A logistic regression model for cycle 1 NE consisting of febrile neutropenia (FN; fever/infection and absolute neutrophil count nadir <1x109/L) or severe neutropenia (SN; neutrophils <.5x109/L) was derived on 1,378 patients with available data. Validation was performed using a split sample random selection process. Results: No significant differences in distribution of NE or predictive factors were observed between derivation dataset (n=922) and validation dataset (n=464). Major independent baseline clinical risk factors for cycle 1 NE in the derivation model (DM) included: anthracycline based regimens (p<.001), non-chemotherapy immune-modulatory agents (p=.003), elevated bilirubin (p=.016), reduced glomerular filtration rate (p<.001), cancer type (p=.02), planned relative dose intensity =85% (p=.027), and regimens containing cyclophosphamide (p<.001), etoposide (p=.002) or ifosfamide (p=.032). Reduced risk of cycle 1 NE was associated with myeloid growth factor (MGF) prophylaxis (p<.001). DM R2 was 0.478 and c-statistic 0.88 [95% CI 0.86–0.91; p<.001]. At median predicted risk of cycle 1 NE of 7%, model test performance (MTP) showed: sensitivity 90%; specificity 59%; and predictive value positive and negative of 32% and 97%, respectively. Cycle 1–4 FN risk in the DM was 16.6% and 3.3% among high and low risk patients, respectively. The validation model (VM) R2 was 0.508 and c-statistic 0.89 [95% CI: 0.86–0.93; p<.001]. MTP in the VM demonstrated: sensitivity 90%; specificity 65%; predictive value positive and negative of 36% and 97%, respectively. Cycle 1–4 FN risk in the VM was 16.8% and 1.6% in high and low risk patients, respectively. Conclusions: This validated risk model demonstrated good discrimination between older cancer patients at decreased risk for NE, and those at increased risk who may benefit from targeted prophylaxis with MGF.

No significant financial relationships to disclose.

Risk factors for hospitalization in elderly cancer patients receiving chemotherapy

9035

Background: Chemotherapy-associated hospitalization is a major source of morbidity and cost in cancer care, particularly for elderly (age ≥ 65) cancer patients. Hospitalization in the elderly often leads to an irreversible decline in functional status unrelated to the acute event that prompted hospital admission. Currently, little is known about the risk factors that may lead to increased risk of hospitalization in elderly patients receiving chemotherapy (CTX). Methods: 871 patients with solid tumors or lymphoma initiating a new CTX regimen were prospectively enrolled at 60 randomly selected US community oncology sites between 8/2004 and 10/2005. Of these, 361 elderly patients aged 65–91 were identified and followed. Primary endpoint of this investigation was hematologic toxicity and hospitalization was secondary. Pre- CTX patient data were analyzed for increased risk of hospitalization in univariate analysis using the chi-square test. Results: A total of 155 (18%) patients were hospitalized resulting in 215 hospitalizations. Median time to first hospitalization was the second cycle of CTX. 81/361 (22%) of elderly patients were hospitalized compared to only 74/510 (15%) of younger patients (p=0.003). The rate of hospitalization increased in a linear fashion between ages 65–80. Reasons for hospitalization in the elderly included infection, fever, or febrile neutropenia (36%), cardiopulmonary disease (CPD) (12%), vomiting or dehydration (13%), other gastrointestinal (11%), transfusion (8%), thrombosis (4%), CTX administration (4%), and other (13%). Major independent pre-CTX factors that predicted hospitalization in the elderly included male gender (p=0.0004), hemoglobin <11 g/dL (p=0.02), abnormal platelet count (<150k or >350k) (p=0.05), CPD (p=0.03), creatinine >1.5 mg/dL (p=0.05), and ≥ 2 concomitant medications (p=0.0008). Elderly patients with lung cancer (p=0.001) and lymphoma (p=0.05) had significantly higher rates of hospitalization when compared to other solid tumors. Conclusions: These data suggest that the risk of hospitalization increases in elderly cancer patients with age and that pre-CTX factors may be useful in identifying a subpopulation at increased risk for hospitalization.

No significant financial relationships to disclose.

Neutropenic complications in ovarian cancer patients receiving chemotherapy: Results of a prospective observational study

19610

Background: A nationwide, prospective cohort study of patients receiving cancer chemotherapy was undertaken to better define treatment-associated toxicities and delivered dose intensity. Methods: Following informed consent, 3,670 patients initiating a new chemotherapy regimen with lymphoma (n=547) or carcinomas of the colon (n=521), breast (n=1,473), lung (n=907) or ovary (n=312) were prospectively registered at 117 randomly selected US oncology practices between March 2002 and December 2005. Pretreatment characteristics including clinical and sociodemographic factors and practice setting associated with reductions in chemotherapy dose intensity over 4 cycles were evaluated. Results: Chemotherapy regimen standards and intended dose and schedule were defined in 97% and 93% of patients, respectively. Average initial (planned) relative dose intensity (RDI) was 90% while the mean RDI actually delivered over 4 cycles was 83%. Reductions in RDI =15% of standard were planned in 23% of patients and actually occurred over 4 cycles in 38%. Body surface area (BSA) calculated by the method of Mosteller exceeded the BSA utilized by the oncology practices in two-thirds of patients most often due to capping at 2 m2. Obese patients with a body mass index (BMI) =30 were more likely to receive planned RDI reductions =15% (30%) than patients with BMI <30 (21%) (P<.0001). Other factors associated with planned reductions in RDI in multivariate analysis included: older age, male gender, lower education, absence of myeloid growth factor prophylaxis and cancers of the lung or ovary as well as the practice setting, size and geographic location. Factors associated with unplanned (subsequent) reductions in RDI included: older age, male gender, poorer Charlson comorbidity index, prior chemotherapy, lung cancer, low baseline hematocrit, white blood or platelet count, poor renal or hepatic function and low serum albumin as well as smaller practice and rural setting. Conclusions: A substantial proportion of patients receiving cancer chemotherapy experience both planned and unplanned reductions in RDI. Further understanding of factors associated with such reductions may provide opportunities for improving the quality of cancer care and clinical outcomes.

[Table: see text]

Factors associated with reductions in chemotherapy dose intensity: Impact of clinical, sociodemographic and practice setting

6550

Background: A nationwide, prospective cohort study of patients receiving cancer chemotherapy was undertaken to better define treatment-associated toxicities and delivered dose intensity. Methods: Following informed consent, 3,670 patients initiating a new chemotherapy regimen with lymphoma (n=547) or carcinomas of the colon (n=521), breast (n=1,473), lung (n=907) or ovary (n=312) were prospectively registered at 117 randomly selected US oncology practices between March 2002 and December 2005. Pretreatment characteristics including clinical and sociodemographic factors and practice setting associated with reductions in chemotherapy dose intensity over 4 cycles were evaluated. Results: Chemotherapy regimen standards and intended dose and schedule were defined in 97% and 93% of patients, respectively. Average initial (planned) relative dose intensity (RDI) was 90% while the mean RDI actually delivered over 4 cycles was 83%. Reductions in RDI =15% of standard were planned in 23% of patients and actually occurred over 4 cycles in 38%. Body surface area (BSA) calculated by the method of Mosteller exceeded the BSA utilized by the oncology practices in two-thirds of patients most often due to capping at 2 m2. Obese patients with a body mass index (BMI) =30 were more likely to receive planned RDI reductions =15% (30%) than patients with BMI <30 (21%) (P<.0001). Other factors associated with planned reductions in RDI in multivariate analysis included: older age, male gender, lower education, absence of myeloid growth factor prophylaxis and cancers of the lung or ovary as well as the practice setting, size and geographic location. Factors associated with unplanned (subsequent) reductions in RDI included: older age, male gender, poorer Charlson comorbidity index, prior chemotherapy, lung cancer, low baseline hematocrit, white blood or platelet count, poor renal or hepatic function and low serum albumin as well as smaller practice and rural setting. Conclusions: A substantial proportion of patients receiving cancer chemotherapy experience both planned and unplanned reductions in RDI. Further understanding of factors associated with such reductions may provide opportunities for improving the quality of cancer care and clinical outcomes.

No significant financial relationships to disclose.

Economic analysis of prophylactic granulocyte colony-stimulating factor (G-CSF) use based on a risk model for neutropenic complications in breast cancer patients receiving adjuvant chemotherapy

6107

Background: Although recent economic analyses of prophylactic G-CSF provide cost saving febrile neutropenia (FN) risk estimates of approximately 20%, many regimens have reported rates <20%. A prospective nationwide cohort study was undertaken to develop risk models for neutropenic complications (NC) including severe and febrile neutropenia in patients receiving cancer chemotherapy (Lyman ASCO 2005). A cost-effectiveness model is presented to evaluate the economic impact of G-CSF prophylaxis based on the model. Methods: Data on 974 consecutive breast cancer patients receiving adjuvant chemotherapy at 115 randomly selected practice sites were analyzed. The clinical and cost impact of G-CSF prophylaxis in high-risk patients based on the model was compared with: 1) no G-CSF; 2) primary prophylaxis; and 3) secondary prophylaxis. Pegfilgrastim costs were based on Medicare pricing while hospitalization costs and mortality on national hospitalization data. Results: Independent predictors of first cycle NC included: type and schedule of chemotherapy, diabetes, elevated bilirubin, planned RDI >85%, low glomerular filtration rate and low neutrophil count. Prophylactic G-CSF was associated with a decreased risk. Model R2=0.327 and c-statistic=0.80 [95% CI: 0.78–0.83; P<.001]. At a baseline FN risk of 8.4% per cycle, the expected costs over four cycles of chemotherapy were: no pegfilgrastim: $1,285; primary prophylaxis: $2,573; secondary prophylaxis: $2,040 and model-targeted G-CSF: $1,527. Expected cost varied with FN risk and model performance. Primary prophylaxis was associated with lower cost than no prophylaxis at FN risk >18%, while the model outperformed both strategies at an FN risk >10%. At a baseline cycle risk of FN of 8.4%, model-guided G-CSF was associated with an expected cost of $44,980 per life saved. Cost savings increased as model discrimination increased. The model was consistently associated with lower cost compared to secondary prophylaxis. Conclusions: A risk model for NC has been developed in breast cancer patients receiving adjuvant chemotherapy. Use of the model to guide G-CSF support appears to be cost-effective at an overall FN risk of 10%.

[Table: see text]

A prediction model for chemotherapy-associated thrombocytopenia in cancer patients

8616

Background: Thrombocytopenia (TP) can lead to serious complications, however, little is known about the incidence and risk factors for chemotherapy-associated TP. A prospective, nationwide cohort study was undertaken to better define the impact of TP in cancer treatment. Methods: 2,842 patients with cancer of the breast, lung, colon, ovary or lymphoma initiating a new chemotherapy regimen have been prospectively enrolled at 115 randomly selected US community oncology practices between 2002 and 2005. Risk factors for chemotherapy-associated TP were identified, a multivariate logistic regression model based on pretreatment characteristics was developed, and test performance characteristics were estimated. Results: Over a median of 3 cycles of chemotherapy, minimum recorded platelet counts were: ≥150K in 53% of patients; 100–150K in 26%; 75–100K in 8%; 50–75K in 6% and <50K in 7%. Significant independent predictive factors for platelets <75K include type of cancer (P<.0001), type of chemotherapy including gemcitabine-based (P<.0001), anthracycline-based (P<.0001) and platinum-based (P<.0001) regimens, prior chemotherapy (P<.0001) or surgery (P=.005), age (P=.015), Caucasian ethnicity (P=.022), body surface area (P=.0001), planned relative dose intensity ≥85% (P=.082), diabetes (P=.018), pulmonary disease (P=.011), abnormal baseline platelets (P<.0001), hematocrit (P=0.030), alkaline phosphatase (P=.072) or albumin (P=.017). Model fit was good (Chi-square, P<.0001), R2 = 0.735 and c-statistic = 0.816 [95% CI: 0.792–0.840, P<.0001]. Model test performance characteristics [95% CI] at a ≥20% risk of TP include: sensitivity 56% [51–61]; specificity 88% [87–89]; likelihood ratio positive 4.63 [4.02–5.33]; likelihood ratio negative 0.50 [0.45–0.57]; and diagnostic odds ratio 9.22 [7.23–11.75]. Validation of the model is underway. Conclusions: This prediction model based on pretreatment factors identifies with high specificity patients at risk for clinically important chemotherapy-associated thrombocytopenia early in the treatment course. It may provide a valuable tool for guiding chemotherapy and new supportive care measures.

[Table: see text]

Social and racial disparities in the use of non-standard breast cancer adjuvant chemotherapy regimens

6036

Background: Economically disadvantaged and black women have worse stage-specific breast cancer outcomes than other women, even after controlling for tumor histologic features. Disparities quality of chemotherapy may contribute to differences in outcome. The purpose of this study was to investigate the use of non-standard breast cancer adjuvant chemotherapy regimens in black women and those of lower socioeconomic status (SES). Methods: Detailed information on patient, disease, and treatment factors was collected prospectively on 1,006 patients receiving adjuvant chemotherapy for early-stage breast cancer in 115 oncology practices throughout the US. All patients signed informed consent. Regimens included in the guidelines of the National Comprehensive Cancer Network were considered standard regimens; all others were considered non-standard. Receipt of non-standard regimens was examined according to clinical and non-clinical factors. Differences between groups were assessed using a chi-square test. Multivariate logistic regression was used to identify factors associated with use of non-standard regimens. Results: Non-standard regimens were used in the treatment of 136 (14%) of the participants. Black patients were twice as likely to receive a non-standard regimen as whites (23% vs. 12%, p = .0014). Patients with less than a high school education were twice as likely to receive a non-standard regimen compared with those with a college education (21% vs. 8%, p = 0.0011). Other factors associated with non-standard chemotherapy regimens were past chemotherapy exposure (p < .0001), higher stage disease (p < .0001) and geographic location (p = 0.0059). Age, comorbidity, body mass index, type of insurance, and employment status were not associated with receipt of non-standard chemotherapy. In multivariate analysis, all variables that were significant in the bivariate analysis remained independently associated with receipt of non-standard chemotherapy. Conclusions: The more frequent use of non-guideline concordant adjuvant chemotherapy regimens in black women and women with lower SES may contribute to their less favorable outcomes. These findings offer an opportunity to improve patient care and perhaps cancer outcomes.

[Table: see text]

A pharmacokinetic-pharmacodynamic model for the mobilization of CD34 hematopoietic progenitor cells by AMD3100

BACKGROUND

AMD3100 is a small-molecule CXCR4 antagonist that has been shown to induce the mobilization of CD34 + hematopoietic progenitor cells from bone marrow to peripheral blood. AMD3100 has also been shown to augment the mobilization of CD34 + cells in cancer patients when administered in combination with granulocyte colony-stimulating factor (G-CSF) (filgrastim). The purpose of this study was to characterize the exposure-response relationship of AMD3100 in mobilizing CD34 + cells when administered as a single agent in healthy volunteers.

METHODS

AMD3100 concentrations and CD34 + cell counts obtained from 29 healthy subjects in a single-dose, intensively sampled pharmacokinetic/pharmacodynamic (PK-PD) study were analyzed by use of nonlinear mixed effects regression with the software NONMEM. FOCE (first order conditional estimation) with interaction was the estimation method, and simultaneous PK-PD fitting was adopted.

RESULTS

The pharmacokinetics of AMD3100 was described by a 2-compartment model with first-order absorption. The population estimates (+/-SE) for clearance and central volume of distribution were 5.17 +/- 0.49 L/h and 16.9 +/- 3.79 L, respectively. CD34 + cell mobilization was best described by an indirect effect model that stimulates the entry process of CD34 + from bone marrow to peripheral blood in the form of a sigmoid maximum effect model. The population estimates (+/-SE) of maximum effect, concentration causing 50% of maximum response, and equilibration time were 12.6 +/- 4.89, 53.6 +/- 11.9 mug/L, and 5.37 +/- 1.31 hours, respectively.

CONCLUSIONS

This study characterizes the exposure-response relationship of AMD3100 in mobilizing CD34 + cells after subcutaneous administration. This PK-PD model will be useful in assessing relevant covariates and for optimizing the use of AMD3100 in various patient populations.

The benefits of haematopoietic growth factors in the management of gynaecological oncology

Neutropenia and anemia are important complications of cancer chemotherapy and can be prevented and treated with granulocyte colony-stimulating factor and erythropoietin.

The rate of apoptosis in post mitotic neutrophil precursors of normal and neutropenic humans

Using data on the fraction of post-mitotic neutrophil precursors (CD15+ cells) displaying positive markers for apoptosis in 12 normal humans, and a simple mathematical model, we have estimated the apoptotic rate to be about 0.28/day in this compartment. This implies that the influx of myelocytes into the post-mitotic compartment exceeds twice the granulocyte turnover rate (GTR), and that about 55% of the cells entering this compartment die before being released into the blood. The normal half life of apoptotic post-mitotic neutrophil precursors is calculated to be 10.4 h. Comparable calculations for patients indicate apoptosis rates in the post-mitotic compartment of about 17 times normal for one myelokathexis patient and rates of about 13 times normal for the one cyclical neutropenic patient and two severe congenital neutropenic patients. The estimated half life for apoptotic post-mitotic neutrophil precursors in the myelokathexis patient was about 0.4 h, 1.4 h in the cyclical neutropenia patient, and about 0.6 h in the severe congenital neutropenic patients.

Mutations in the neutrophil elastase gene in cyclic and congenital neutropenia

Severe neutropenia disorders are characterized by extremely low levels of peripheral blood neutrophils, a maturation block of bone marrow progenitor cells and recurring severe bacterial and fungal infections. Recent reports indicated that severe neutropenia is a consequence of an impaired survival and abnormal cell cycle progression of myeloid progenitor cells in both cyclic and severe congenital neutropenia. Mutations in the neutrophil elastase gene were identified in all patients with cyclic neutropenia and most of the patients with severe congenital neutropenia. We hypothesize that expression of mutant neutrophil elastase protein results in deregulation of intracellular activity and premature cell death of myeloid-committed progenitor cells in these disorders, resulting in the lack of peripheral blood neutrophils. The potential molecular mechanisms of mutant-protein-mediated neutropenia is discussed.

Granulocyte transfusion therapy: update on potential clinical applications

The clinical usefulness of granulocyte transfusions for treatment or prevention of life-threatening bacterial and fungal infections remains controversial. Clinical benefit has long been limited by insufficient donor stimulation regimens and suboptimal leukapheresis techniques. Methodologic progress, in particular mobilization of neutrophils in healthy donors by administration of G-CSF, has significantly enhanced leukapheresis yields. A newly published study indicates that unrelated community donors can be effectively and safely used as an alternative to related family donors. Furthermore, several recent studies suggest that it may be possible to store granulocyte concentrates for 24 to 48 hours with adequate preservation of neutrophil function. This review summarizes the current role of granulocyte transfusion therapy in infectious diseases and highlights important recent advances.

Current status of granulocyte (neutrophil) transfusion therapy for infectious diseases

The transfusion of neutrophils, or granulocyte transfusion therapy, has long been considered as a logical approach to the treatment of severe bacterial and fungal infections in patients with prolonged neutropenia or intrinsic defects in neutrophil function. However, despite numerous clinical trials, the efficacy and safety of granulocyte transfusion therapy remain controversial. Efficacy has been compromised largely by the inability to transfuse sufficient quantities of functionally active neutrophils to patients. The recent use of recombinant granulocyte colony-stimulating factor (G-CSF) to mobilize neutrophils in donors before centrifugation leukapheresis has rekindled interest in the potential clinical applications of granulocyte transfusion therapy. This review focuses on the use of G-CSF for donor stimulation and summarizes the current status of granulocyte transfusion therapy for treatment of infectious diseases.

Impaired survival of bone marrow hematopoietic progenitor cells in cyclic neutropenia

Cyclic neutropenia (CN) is a congenital hematopoietic disorder characterized by remarkably regular oscillations of blood neutrophils from near normal to extremely low levels at 21-day intervals. Recurring episodes of severe neutropenia lead to repetitive and sometimes life-threatening infections. To investigate the cellular mechanism of CN, the ultrastructure and the proliferative and survival characteristics of bone marrow-derived CD34(+) early progenitors, CD33(+)/CD34(-) myeloid progenitors, and CD15(+) neutrophil precursors from CN patients and healthy volunteers were studied. The ultrastructural studies showed profound apoptotic features in bone marrow progenitor cells in CN. Colony-forming assays demonstrated a 75% decrease in the number of early myeloid-committed colonies compared with controls. Long-term culture-initiating cell assays demonstrated a 6-fold increase in production of primitive progenitor cells in CN. To determine whether accelerated apoptosis might account for the underproduction of myeloid progenitors, the hematopoietic subpopulations were labeled with fluorescein isothiocyanate-annexin V and analyzed by flow cytometry. Short-term culture of CN cells resulted in apoptosis of approximately 65% of CD34(+) cells, 80% of CD33(+)/CD34(-) cells, and more than 70% of CD15(+) cells, as compared with 20%, 7%, and 15% apoptosis in respective control subpopulations. Evidence of accelerated apoptosis of bone marrow progenitor cells was observed in all 8 patients participating in the study, regardless of the stage in the CN cycle in which bone marrow aspirations were obtained. Granulocyte colony-stimulating factor therapy of CN patients significantly improved survival of bone marrow progenitor cells. These data indicate that ineffective production of neutrophils is due to accelerated apoptosis of bone marrow myeloid progenitor cells in CN.

Spontaneous remission of granulocyte colony-stimulating factor-associated leukemia in a child with severe congenital neutropenia

Leukemia is observed with increased frequency in patients with severe congenital neutropenia (SCN). In the past decade, recombinant human granulocyte colony-stimulating factor (rh G-CSF) has prolonged the survival of patients with SCN increasingly reported to have leukemias. In this communication acute myelogenous leukemia (AML) associated with a mutation of the G-CSF receptor (G-CSF-R) developed in a patient with SCN maintained on long-term G-CSF therapy. The blast count in the blood and bone marrow fell to undetectable levels twice on withholding G-CSF and without chemotherapy administration, but the mutant G-CSF-R was detectable during this period. The patient subsequently underwent successful allogeneic bone marrow transplantation. After transplantation, the patient's neutrophil elastase (ELA-2) mutation and G-CSF-R mutation became undetectable by polymerase chain reaction. This report provides novel insights on leukemia developing in congenital neutropenia.

Mutations in the gene encoding neutrophil elastase in congenital and cyclic neutropenia

Congenital neutropenia and cyclic neutropenia are disorders of neutrophil production predisposing patients to recurrent bacterial infections. Recently the locus for autosomal dominant cyclic neutropenia was mapped to chromosome 19p13.3, and this disease is now attributable to mutations of the gene encoding neutrophil elastase (the ELA2 gene). The authors hypothesized that congenital neutropenia is also due to mutations of neutrophil elastase. Patients with congenital neutropenia, cyclic neutropenia, or Shwachman-Diamond syndrome were referred to the Severe Chronic Neutropenia International Registry. Referring physicians provided hematologic and clinical data. Mutational analysis was performed by sequencing polymerase chain reaction (PCR)-amplified genomic DNA for each of the 5 exons of the neutrophil ELA2 gene and 20 bases of the flanking regions. RNA from bone marrow mononuclear cells was used to determine if the affected patients expressed both the normal and the abnormal transcript. Twenty-two of 25 patients with congenital neutropenia had 18 different heterozygous mutations. Four of 4 patients with cyclic neutropenia and 0 of 3 patients with Shwachman-Diamond syndrome had mutations. For 5 patients with congenital neutropenia having mutations predicted to alter RNA splicing or transcript structure, reverse transcriptase-PCR showed expression of both normal and abnormal transcripts. In cyclic neutropenia, the mutations appeared to cluster near the active site of the molecule, whereas the opposite face was predominantly affected by the mutations found in congenital neutropenia. This study indicates that mutations of the gene encoding neutrophil elastase are probably the most common cause for severe congenital neutropenia as well as the cause for sporadic and autosomal dominant cyclic neutropenia.

Inhibition of in vivo neutrophil transmigration by a novel humanized anti-CD11/CD18 monoclonal antibody

Leukocyte adhesion receptors, including the beta-integrin (CD11/CD18) family, play an important role in inflammation via their regulatory effects on leukocyte adhesion, transmigration, and function. A randomized, placebo-controlled, double-blind study was conducted in healthy volunteers to evaluate the in vivo effects of a humanized anti-CD11/CD18 monoclonal antibody, Hu23F2G, on leukocyte activation and transmigration. Neutrophil migration to a site of cutaneous inflammation in vivo, as measured by the skin chamber technique, was significantly reduced in subjects 24 hours after Hu23F2G administration. At 96 hours, neutrophil migration was not significantly different in subjects who received Hu23F2G or placebo. In contrast, delayed-type hypersensitivity (DTH) testing, which involves activation and migration of T lymphocytes and macrophages, was unaffected by the Hu23F2G treatment. These responses to Hu23F2G in vivo are similar to the clinical phenotype of leukocyte adhesion deficiency (LAD) type 1, a congenital disorder of CD18 deficiency. The in vivo properties of Hu23F2G suggest therapeutic potential for use in the treatment of acute non-infectious inflammatory disorders mediated predominantly by neutrophils.

Myelodysplasia syndrome and acute myeloid leukemia in patients with congenital neutropenia receiving G-CSF therapy

Granulocyte colony-stimulating factor (G-CSF) has had a major impact on management of "severe chronic neutropenia," a collective term referring to congenital, idiopathic, or cyclic neutropenia. Almost all patients respond to G-CSF with increased neutrophils, reduced infections, and improved survival. Some responders with congenital neutropenia have developed myelodysplastic syndrome and acute myeloblastic leukemia (MDS/AML), which raises the question of the role of G-CSF in pathogenesis. The Severe Chronic Neutropenia International Registry (SCNIR), Seattle, WA, has data on 696 neutropenic patients, including 352 patients with congenital neutropenia, treated with G-CSF from 1987 to present. Treatment and patient demographic data were analyzed. The 352 congenital patients were observed for a mean of 6 years (range, 0.1-11 years) while being treated. Of these patients, 31 developed MDS/AML, for a crude rate of malignant transformation of nearly 9%. None of the 344 patients with idiopathic or cyclic neutropenia developed MDS/AML. Transformation was associated with acquired marrow cytogenetic clonal changes: 18 patients developed a partial or complete loss of chromosome 7, and 9 patients manifested abnormalities of chromosome 21 (usually trisomy 21). For each yearly treatment interval, the annual rate of MDS/AML development was less than 2%. No significant relationships between age at onset of MDS/AML and patient gender, G-CSF dose, or treatment duration were found (P >.15). In addition to the 31 patients who developed MDS/AML, the SCNIR also has data on 9 additional neutropenic patients whose bone marrow studies show cytogenetic clonal changes but the patients are without transformation to MDS/AML. Although our data does not support a cause-and-effect relationship between development of MDS/AML and G-CSF therapy or other patient demographics, we cannot exclude a direct contribution of G-CSF in the pathogenesis of MDS/AML. This issue is unclear because MDS/AML was not seen in cyclic or idiopathic neutropenia. Improved survival of congenital neutropenia patients receiving G-CSF therapy may allow time for the expression of the leukemic predisposition that characterizes the natural history of these disorders. However, other factors related to G-CSF may also be operative in the setting of congenital neutropenia. (Blood. 2000;96:429-436)