Differences in survival for patients with metastatic colorectal cancer by lines of treatment received and stage at original diagnosis

OBJECTIVE

Few published studies have examined survival rates for patients with metastatic colorectal cancer (mCRC) by number of lines of treatment received or stage at diagnosis. This study aims to evaluate survival and numbers of lines of treatment in USA mCRC managed care patients.

METHODS

To evaluate the impact of chemotherapy/biological on survival of patients with mCRC, adults with a diagnosis of CRC between 1 January 2005 and 31 May 2010 were identified from the Oncology Management registry. Registry data included stage and diagnosis date. Patients with stage IV CRC at original diagnosis or development of metastasis were included. Linked healthcare claims from a large USA database were used to identify lines of treatment after metastasis and patient characteristics. The patient population was enrolled in a commercial health insurance programme, with 10% of patients > 65 years of age. Patients were categorised by lines of treatment received (0, 1, 2, 3+) and stage at original diagnosis (0-3, 4, unknown). Survival following metastasis was evaluated using Cox proportional hazards models controlling for lines of treatment, disease stage, and other patient characteristics.

RESULTS

Study population included commercially insured adult patients, ≥ 18 years of age (n = 598, mean age 54, 56% male), 16% of which did not receive chemotherapy/biological therapy after becoming metastatic, and 33% received only 1 line of treatment. Average follow-up was 653 days, and 19% of patients died during the study period. Mean unadjusted length of follow-up was 516, 511, 627 and 930 days for patients who received 0, 1, 2 and 3+ lines of treatment, respectively. In the Cox proportional hazards model, geographical region was the only variable significantly associated with survival (p < 0.05).

CONCLUSION

Lines of treatment received and stage at original diagnosis were not statistically significantly associated with survival after metastasis development.

The economic burden of skeletal-related events among elderly men with metastatic prostate cancer

BACKGROUND AND OBJECTIVE

Advanced prostate cancer patients with bone metastasis are predisposed to skeletal complications termed skeletal-related events (SREs). There is limited information available on Medicare costs associated with treating SREs. The objective of this study was to ascertain SRE-related costs among older men with metastatic prostate cancer in the US.

METHODS

We analysed patients aged 66 years or older who were diagnosed with incident stage IV (M1) prostate cancer between 2000 and 2007 from the linked Surveillance, Epidemiology and End Results (SEER)-Medicare dataset. A propensity score for the incidence of an SRE was estimated using a logistic regression model including demographic and clinical baseline variables. Patients with SREs (cases) were matched to patients without SREs (controls) based on the propensity score, length of follow-up (i.e. date of prostate cancer diagnosis to last date of observation) and death. Health resource utilization cost differences between cases and controls over time were compared using generalized linear models. Healthcare costs were examined by type of SRE (pathological fracture only, pathological fracture with concurrent surgery, spinal cord compression only, spinal cord compression with concurrent surgery, and bone surgery only) and by source of care (inpatient, physician/non-institutional provider, skilled nursing facility, outpatient and hospice). All costs were adjusted to 2009 US dollars, using the medical care component of the Consumer Price Index.

RESULTS

Application of the inclusion criteria resulted in 1,131 metastatic prostate cancer patients with SREs and 6,067 patients without SREs during follow-up. The average age of the sample was 79 years, and 14 % were African American. A total of 928 patients with SREs were matched to 928 patients without SREs. The average health care utilization cost of patients with SREs was US$29,696 (95 % confidence interval [CI] US$24,730-US$34,662) higher than that of the controls. The most expensive SRE group was spinal cord compression with concurrent surgery (US$82,868: 95 % CI US$67,472-US$98,264) followed by bone surgery only (US$37,496: 95 % CI US$29,684-US$45,308), pathological fracture with concurrent surgery (US$34,169: 95 % CI US$25,837-US$ 42,501), spinal cord compression only (US$25,793: 95 % CI US$20,933-US$30,653) and pathological fracture only (US$14,649: 95 % CI US$6,537-US$22,761). The largest cost difference by source of care was observed for hospitalizations (p < 0.01).

CONCLUSION

Metastatic prostate cancer patients with SREs incur higher costs compared to similar patients without SREs. SRE costs among older stage IV (M1) prostate cancer patients vary by SRE type, with spinal cord compression and concurrent surgery costing at least twice as much as other SREs.

Docetaxel in Combination with Doxorubicin and Cyclophosphamide as Adjuvant Treatment for Early Node-Positive Breast Cancer in the USA: A Cost-Effectiveness and Cost-Utility Analysis

OBJECTIVE9/15/2009 To estimate the cost effectiveness of TAC (docetaxel 75mg/m2, doxorubicin 50mg/m2, and cyclophosphamide 500mg/m2 6 cycles) compared with FAC (fluorouracil 500mg/m2, doxorubicin 50mg/m2, and cyclophosphamide 500mg/m2 6 cycles) when administered as adjuvant therapy to women with node-positive early breast cancer in the USA, both with and without primary prophylaxis with granulocyte colony-stimulating factor (G-CSF).METHODS: A Markov model estimated costs and outcomes from initiation of adjuvant chemotherapy to death. Patient-level data from the Breast Cancer International Research Group (BCIRG) 001 trial provided estimates of the effect of chemotherapy on toxicity and outcome. Costs were estimated from US databases (Pharmetrics and Premier) and a published analysis of linked SEER-Medicare data for 1580 patients with disease recurrence (cost year 2008). Utility weights were estimated from Organization for Research and Treatment of Cancer Core Questionnaire (EORTC QLQ-C30) data collected in trial BCIRG 001 and from the published literature. Probabilistic sensitivity analysis was performed in which the mean value of each model parameter was sampled randomly from its statistical distribution. 1,000 simulations were performed to generate a distribution of total expected costs, life years and quality-adjusted life years (QALYs), which reflected the aggregated uncertainty of the model parameters.RESULTS: The results are presented in Table 1 and Figure 1.Table 1. Total expected lifetime costs and outcomes for patients receiving TAC and FAC TACFACIncremental difference (TAC - FAC)Mean Cost per patient (95% Confidence Intervals)$33,379 ($27,530 - $48,320)$13,647 ($10,764 - $17,707)$19,732 ($15,869 - $31,441)Mean life years per patient (95% Confidence Intervals)12.43 (12.04 - 12.94)11.51 (11.08 - 12.05)0.93 (0.87 - 0.97)Mean QALYs per patient (95% Confidence Intervals)9.53 (6.18 - 11.54)8.79 (5.72 - 10.64)0.74 (0.44 - 0.91) Over patients' lifetimes, the incremental cost per life-year saved associated with use of TAC rather than FAC was estimated as $21,318 (95% confidence intervals, $16,953 to $33,856) and the incremental cost per QALY was $26,654 ($18,553 to $50,554). The addition of primary G-CSF (filgrastim) to the TAC regimen resulted in an incremental cost per life-year saved of $21,775. The results were most sensitive to the quality-of-life score for patients in remission postchemotherapy. However, even if quality of life was assumed to be as poor as for patients with metastatic disease, the incremental cost per QALY estimate rose only to $44,122.CONCLUSION: Use of adjuvant TAC rather than FAC for node-positive early breast cancer patients is cost effective in the US setting, despite the increased drug cost and the cost and quality of life implications of toxicity. TAC supported by primary G-CSF prophylaxis is also cost-effective compared with FAC.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 2091.

Patient Characteristics Associated with Use of Monoclonal Antibody Treatment in Women with Metastatic Breast Cancer: A Population-Based Analysis

Introduction: Monoclonal antibodies (MoATB) were FDA approved for the treatment of patients with breast cancer (BrCA) whose tumors over expressed the human epidermal growth factor receptor 2 (HER2) in 1998. We sought to determine if certain patient characteristics and co-morbidities influenced MoATB use in a population-based practice setting of elderly women with metastatic BrCA. Methods: We identified female Medicare beneficiaries aged 66+ years diagnosed with incident metastatic BrCA without prior history for any cancer between 1999 and 2005 in the Surveillance, Epidemiology and End Results cancer registries (SEER). Charlson Co-morbidity index (CCI) and separate conditions within the index were created using linked Medicare claims in the year prior to the BrCA diagnosis. We identified both oral and infused chemotherapy (CH) from the Medicare claims from 1999 to 2006. Patients were categorized into three groups: no CH, MoATB+/-CH, and CH w/out MoATB. We performed bivariate statistics to compare the patient characteristics and comorbidities between the three groups, and the treatments groups only. Results: There were 3,820 women with metastatic BrCA, mean age 77 (SD 7.3) years, 81% were white race, 29% were married and 91% lived in an urban setting. 67% of these women (n=2,562) received no CH, 26% received CH w/out MoATB (n=994) and 7% received MoATB+/-CH (n=264). Overall the CCI was lower for women receiving either treatment as compared to no chemotherapy and between treatment groups for the young old (66-75 years) but not those aged 80+ years. The prevalence of congestive heart failure (CHF) and cerebrovascular disease was significantly lower in women receiving MoATB +/-CH, as compared to only CH, and also lower in both compared to no CH (n=2,462). Few women presenting with COPD or dementia were likely to be treated with either CH and/or MoATB compared to No CH. Other co-morbidity conditions within the CCI were not statistically different between the groups or the cell numbers were too small to analyze. Conclusion: MoATB use in the treatment of metastatic breast cancer steadily increased from 5% in 1999 to 23% in 2004. Use in 2005 was slightly lower but will be recalculated once the 2007 claims are available. In 2008, FDA released a black box warning for trastuzumab, the most frequently prescribed MoATB for BrCA, regarding the potential for the development of cardiomyopathy. Our results suggest that co-morbidities in particular CHF and cerebrovascular disease may influence the decision to use MoATB. Further research is necessary to examine the relationship between co-morbidities and the use of MoATB in the treatment of metastatic breast cancer.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 2057.

Taxane Treatment in Women with Incident Stage IV Breast Cancer

Introduction: The overall benefit of chemotherapy for late stage breast cancer treatment has been demonstrated in clinical trials and “real world” observational studies, but there is less data on chemotherapy use among older women. In addition, estrogen receptor status can influence treatment decisions. Our objective was to explore the clinical and demographic characteristics of women who received chemotherapy, particularly taxanes, in a large population-based cohort of older patients with incident stage IV breast cancer.Methods: Older women (age 66 and over) diagnosed with incident stage IV breast cancer from 1999 to 2005 were identified in the Surveillance, Epidemiology and End Results (SEER) cancer registries. Treatment-related data were linked from Medicare claims. We limited our analysis to ER negative (ER-) women with the assumption that these women would not be receiving tamoxifen as SEER data do not have complete information on receipt of tamoxifen. Receipt of chemotherapy was identified from claims files. Bivariate analyses were performed to compare clinical and demographic characteristics of those who received taxanes, other chemotherapy, or no chemotherapy.Results: Of 3,820 older women diagnosed with incident stage IV breast cancer, 1,518 women (40%) were identified as ER negative, of whom 247 (16%) were treated with taxanes, 312 (21%) with other chemotherapy, and the remainder received neither. Mean age was 78, 84% of the study cohort was white, 27% were married, and 91% lived in urban areas. Fifty four percent of women had HER2 assays performed. Women who received taxanes were substantially younger (Mean=74, SD=5.49) than those who did not (Mean=80, SD=7.79) and had fewer co-morbidities (measured by Charlson co-morbidity index) (bivariate [see above] p=0.0003) than any other group. Individuals who received taxanes were less likely to be married, receive radiation or undergo surgery. Only 8% of those treated with taxanes had 2 or more medical conditions compared to 18% of those receiving other chemotherapy and 74% of those with no chemotherapy. Treatment groups varied in regard to some medical conditions including CHF, cerebrovascular disease, and dementia. For example, only 8% of those receiving taxanes had CHF, compared to 13% among the 'other chemotherapy' group and 78% among those receiving no treatment (bivariate [see above] p=0.0003). A similar trend was revealed with the other medical conditions, with taxane users consistently presenting with lower prevalence for each condition. Interestingly, no one who had dementia received any chemotherapy.Conclusion: Findings from this descriptive study showed that age and co-morbidity were the most important factors associated with receipt of taxanes as well as of other chemotherapy. However, those who received taxanes were the youngest and evidenced the least comorbidity of the 2 groups. Further study is needed to help inform clinicians in making optimum treatment recommendations for their older female patients with incident advanced breast cancer.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 2068.

Chemotherapy Treatment and Survival in Estrogen Receptor Negative Metastatic Breast Cancer: A Population-Based Analysis

Introduction: Although controlled clinical trials have demonstrated a beneficial effect of various chemotherapy regimens on survival in breast cancer (BC), little is known about treatment patterns and survival benefit in the “real world” population of elderly women with metastatic BC. Methods: We identified female Medicare beneficiaries aged ≥66 years with metastatic BC diagnosed from 1999 to 2005 in the Surveillance, Epidemiology and End Results cancer registries (SEER). Patients with a prior history of any cancer were excluded. Treatment-related data were abstracted from linked Medicare claims. Since Medicare claims have incomplete information on oral selective estrogen receptor modulators, we limited our study cohort to estrogen receptor negative (ER-) women. Chemotherapy was defined as the receipt of any chemotherapeutic regimen within 6 months after diagnosis. Initial regimens were characterized based on drugs given during the first 30 days of chemotherapy. We used a continuous-time interval-censored survival analysis to determine the effect of chemotherapy on hazard of any-cause death, controlling for sociodemographic and clinical factors, including proxy measures for performance status. Results: We identified 1518 ER(-) women diagnosed with metastatic BC in SEER. Mean age was 77.6 (SD 7.6) years, 84% were white race and 27% were married at the time of diagnosis. Of the 1518 metastatic ER(-) BC patients, 493 (32%) received chemotherapy. As compared to women who did not receive chemotherapy, women who received chemotherapy were more likely to be younger, married, have lower pre-cancer comorbidity as measured by the Charlson comorbidity index, have seen an oncology specialist and have cancer-directed surgery or radiation prior to chemotherapy. Initial regimens comprised predominantly one (31%) or two (46%) drug classes. The most common regimens were taxanes only (18%), anthracycline+alkylating agents (17%) and antimetabolite+alkylating agent (9%). Overall median followup time was 7 months; 1223 women (81%) died during followup. Median survival time was 5 months among women who did not receive chemotherapy and 15 months among women who received chemotherapy. Chemotherapy was associated with a statistically significant survival benefit (adjusted Hazard Ratio 0.61, 95% confidence interval 0.54, 0.70). Conclusion: In this population-based study of older women, there was a variety of chemotherapy regimens used for metastatic ER(-) BC. Chemotherapy received within 6 months after diagnosis was associated with a 39% reduction in hazard of death. These findings reflect chemotherapy use outside of the clinical trial setting and have important clinical and policy implications for the study of treatments among older women with advanced BC.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 2064.

Visit and treatment patterns over time among elderly patients (pts) with M1 prostate cancer (PC): An analysis using SEER-Medicare

5170

Background: Treatment options for the management of pts diagnosed with M1 PC have evolved over time. It is unknown whether visits to medical oncologists/hematologist oncologists (MOH) and treatment patterns are also changing over time. The objective of this study is to examine changes in visit and treatment patterns over time. Methods: A retrospective analysis of SEER Medicare data included pts diagnosed with M1 PC from 1994–2002 (age > 65 years) and residing in SEER registries that were present for the entire period. The study included pts with a post-diagnosis visit to a urologist; pts who saw a MOH prior to the urologist visit were excluded. Pts were grouped as 1) no MOH visit, 2) MOH visit w/in 3 mos of a urologist visit, 3) MOH visit => 3 mos after a urologist visit. Treatment with hormone therapy or chemotherapy was defined as 1) none received; 2) timely (i.e. within 6 mos of diagnosis); and 3) delayed, i.e. => 6 mos following the diagnosis. Time periods were defined as early (1994–1996), middle (1997–1999) and late (2000–2002). Results: 3,269 pts (mean age 77, 81% white) were available for analysis. Ninety-three percent of pts received treatment. Thirty-eight percent of pts saw a MOH during the study period; over the study period (early; middle; late) 13% (10%; 13%; 17%) of pts had a timely visit to the MOH and 25% (24%; 28%; 25%) had a delayed visit to the MOH. The proportion of patients seeing a MOH increased (34%; 41%; 42%, p < 0.001) and the proportion of treated pts increased (93%; 93%; 95%, p = 0.03) over the early, middle, and late periods. Conclusions: Approximately one-third of patients with M1 disease and a post-diagnosis urologist visit also see a medical oncologist. The vast majority of these patients receive treatment. Over time, a larger proportion of patients are seeing medical oncologists.

[Table: see text]

The economic implications of rasburicase treatment in pediatric tumor lysis syndrome patients

10050

Background: Rasburicase is a recombinant urate-oxidase enzyme used to reduce high levels of plasma uric acid (UA) resulting from tumor lysis syndrome (TLS) in pediatric patients. Rasburicase reduces UA levels within 4 hours of administration, minimizing risk of serious complications from TLS. Although the efficacy of rasburicase has been demonstrated in clinical trials, there are few studies that have evaluated the economic implications of using rasburicase rather than allopurinol, the current standard of care. Methods: Pediatric patients administered rasburicase or allopurinol within 2 days of hospital admission were eligible for study inclusion. Patients were excluded if they were ≥ 18 years of age or received hemodialysis on admission. Patients receiving allopurinol or combination therapy were then propensity score matched to rasburicase patients based on gender, race, hospital type, provider type, payer type, admission source, use of electrolyte modification therapy, critical care admission, and comorbid diagnoses. Differences in healthcare costs, length of stay, and duration of subsequent critical care were assessed using gamma distributed generalized linear models with a log link function. Results: There were 63 allopurinol and 63 rasburicase patients matched in the analysis. The mean age of the sample was 7.4 years, with 27% being female. There were no statistical differences in matched covariates across the cohorts. Rasburicase patients incurred an average of $30,470 per hospitalization compared to $35,165 for allopurinol patients (p = 0.427). Mean length of stay was not statistically different across the cohorts, averaging 14 days. Duration of critical care was significantly lower for rasburicase (1.4 days) when compared to allopurinol (2.5 days, p = 0.0001). Conclusions: Treatment with rasburicase is associated with similar costs and a lower duration of critical care when compared to allopurinol therapy.

[Table: see text]

Long-term survival benefits of docetaxel plus cyclophosphamide compared to doxorubicin plus cyclophosphamide in the adjuvant treatment of operable breast cancer

563

Background: The U.S. Oncology Adjuvant Trial 9735 recently demonstrated disease-free survival and overall survival (OS) benefits over 7 years for docetaxel plus cyclophosphamide (TC) compared with doxorubicin plus cyclophosphamide (AC) as adjuvant treatment for women with operable stage I-III invasive breast cancer (BC). The life-time benefits of TC vs. AC, however, are unknown. This analysis aimed to project potential life-time survival benefits of TC vs. AC as adjuvant therapy for operable BC. Methods: The 7-year follow-up results of the 9735 study combined with US average life expectancy were used to project the life-time survival benefits of TC vs. AC. In the base case (scenario 1), it was assumed the survival advantage of TC did not persist beyond the 7-year clinical trial period. Rather, all patients alive and disease-free at 7 years (from the starting age of 51 to the age of 58), regardless of treatment, were assumed to be cured and received the average remaining life expectancy of a 58-year old woman in the US general population. As survival benefits from chemotherapy may persist beyond the clinical trial period, two sensitivity analyses were conducted: 1) greater life expectancy in the TC arm of 1.8 months equivalent to the mean difference in OS between TC and AC within the clinical trial period (scenario 2) and 2) greater life expectancy in the TC arm of 22 months equivalent to the difference in survival at the end of 7 years (scenario 3). The total life years gained (LYs) and quality-adjusted life years gained (QALYs) were then calculated. Results: Per patient LYs gained in scenarios 1, 2, and 3 were 0.850, 0.930, and 1.755, respectively; while QALYs gained were slightly lower at 0.674, 0.736 and 1.383, respectively. Applying this benefit to a cohort of 167,133 women in the US with newly diagnosed stage I-III invasive BC in 2008, the gains were 142,063 LYs and 112,648 QALYS in scenario 1. Conclusions: In addition to survival benefit observed within the clinical trial period, the use of TC is associated with long-term survival benefits compared to AC in patients with stage I-III invasive BC. The results provide additional support of the value of TC in the management of early stage BC.

[Table: see text]

The economic implications of rasburicase treatment in adult tumor lysis syndrome patients

e17503

Background: Rasburicase is a recombinant urate-oxidase enzyme used to reduce high levels of plasma uric acid (UA) resulting from tumor lysis syndrome (TLS). Rasburicase reduces UA levels within 4 hours of administration, minimizing risk of serious complications from TLS. Treatment pattern analyses indicate rasburicase is often used in combination with allopurinol; however, no studies have evaluated clinical and economic consequences of this pattern of care. The purpose of the study was to compare hospitalization costs, length of stay (LOS), and duration of critical care in patients receiving rasburicase with or without allopurinol. Methods: Patients in the Premier hospital database administered rasburicase or combination therapy within 2 days of hospital admission were eligible for study inclusion. Patients were excluded if they were <18 years of age or received hemodialysis on admission. Patients were propensity score matched to rasburicase patients based on gender, race, hospital type, provider type, payer type, admission source, use of electrolyte modification therapy, critical care admission, and comorbid diagnoses. Differences in health care costs, LOS, and duration of subsequent critical care were assessed using exponentially distributed generalized linear models with a log link function. Projection weights are used to produce national projected patient counts. Results: There were 280 rasburicase and 310 combination patients matched in the analysis. Mean age of the sample was 65.2, with 31% being female. There were no statistical differences in matched covariates across the cohorts. Rasburicase patients incurred an average total cost of $39,474 per hospitalization compared to $52,047 for combination patients (p = 0.0029). Rasburicase patients also had a lower LOS (10.5 days) compared to combination therapy (16.4 days, p < 0.0001). Duration of critical care was similar in both cohorts (rasburicase = 1.4 days vs 1.8 days, p = 0.1222). Conclusions: Combination therapy of rasburicase and allopurinol resulted in higher total hospitalization costs and longer LOS compared to rasburicase monotherapy.

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The impact of docetaxel (D) in an older population of patients with advanced prostate cancer (PC): A simulation study using TAX327 and SEER Medicare data

e16074

Background: The survival benefit of D in treatment of hormone refractory PC (HRPC) has been established in the TAX327 trial, but it is unclear how this benefit would translate in a heterogeneous population. This study sought to simulate the survival impact of D in a population of older pts with M1 PC on androgen deprivation therapy (ADT). Methods: A combination of TAX327 trial data and SEER-Medicare (SM) data were used. In pts age 69+ and randomized to D (every 3 weeks, D3P) or mitoxantrone (M), trial data showed a survival benefit for D. Accordingly, SM pts age 69+ diagnosed with M1 PC between 1994 and 2002 and receiving only ADT were selected. Graphical plots and statistical tests were used to find best-fitting parametric survival functions for D3P, M, and SM pts. The survival benefit for D was imposed on unadjusted and covariate-adjusted SM survival curves. The simulated benefit was assessed at 12 mos and 24 mos post-diagnosis of M1 PC in SM pts. Results: There were 326 TAX327 trial pts (D3P = 159, M = 167) used in the analysis. Median survival was 15.7 mos (12.6 - 19) in the M arm and 18.9 mos [17 - 21.8] in the D3P arm (p = 0.03). There were 3,515 SM pts, based on inclusion criteria. Median survival benefit of D was 3.2 mos based on Kaplan-Meier estimates and 2.4 mos using parametric curves in the TAX327 69+ group. Following covariate-adjustment in the SM sample, at 12 mos post-diagnosis, the median survival in mos was 61.7 (CI 36.3 - 87) in the ADT group and 62 (CI 37.6 - 87.1) in the simulated ADT+D group (i.e., 0.3 mos simulated benefit of D). A 0.8 mos simulated benefit was found if D was initiated 24 mos post diagnosis (in pts more likely to have HRPC). Conclusions: The survival benefit of docetaxel from the TAX327 trial is attenuated in a heterogeneous SEER-Medicare sample, and the simulated survival benefit is larger among patients who are more likely to have hormone refractory prostate cancer.

[Table: see text]

Characteristics of elderly metastatic prostate cancer (M1 PC) long-term survivors in the SEER Medicare database receiving androgen-deprivation therapy (ADT)

e17513

Background: ADT remains standard treatment for pts with M1 PC, with radiation (RT) and chemotherapy (CT) providing additional palliation. This population-based analysis evaluated if long-term survivors (LT) receiving ADT possessed different characteristics relative to short-term survivors (ST). Methods: Pts age >/= 66y in SEER Medicare diagnosed with M1 PC between 1998 and 2002 and receiving ADT with or without subsequent CT were identified. Median overall survival (OS) for the sample was used as a cut-off to categorize ST and LT pts. Within these categories, demographic, and clinical characteristics were evaluated. Results: 2,665 ADT pts were first identified who had median OS of 26 months (95% CI 24.0 - 27.0). 1,349 pts died at </= 26 months (ST pts), while 1,245 pts survived or were lost to follow-up beyond 26 months (LT pts). Median time to first treatment with ADT was 1 mo in both ST and LT groups. Within this 66y+ population, LT pts were younger (p < 0.0001), more likely to be married (p = 0.0277), and were comprised of lower % of non-Hispanic white pts and higher % of ‘other’ races, but comparable % of African American and White-Hispanics (p = 0.0005). Distributional differences in PSA were detected, but interpreting the results was difficult due to missing or unknown information. Both ST and LT pts received RT and prostatectomy at similar rates, but LT pts had less comorbidities (p = 0.0008), and were more likely to receive CT (p = 0.0026). Conclusions: Long-term survivors were found to have demographic and clinical characteristics that differed from short-term survivors. Evidence regarding how these characteristics simultaneously impact the type and timing of treatment as well as survival deserve more exploration.

[Table: see text]

The impact of time of medical oncologist visit on survival among elderly patients with stage IV prostate cancer: An analysis using SEER-Medicare data

e17509

Background: The association between physician referrals and treatment receipt has been established in other disease settings. The impact of time to a medical oncologist or hematologist/oncologist (MOH) visit on survival has not been examined in patients (pts) with advanced prostate cancer (A-PC). The objective of this study is to determine whether the time to a MOH visit is associated with survival. Methods: The SEER-Medicare database was used for the analysis. Pts aged >65 diagnosed with A-PC between 1994 and 2002 and who visited a urologist post-diagnosis were included. Pts who saw a MOH before the urologist visit were excluded. For pts who saw a MOH, time to a MOH visit was identified using the diagnosis date and the urologist visit as starting points. Survival models were used to examine the effect of the time (in months) to MOH visit on survival, controlling for demographic, clinical, continuity-of-care, and ecological measures. Results: There were 6,498 pts in the sample (mean age 76 years, 82% White race). PC-specific mortality was 38%. Two-thirds (67%) of patients did not visit a MOH after visiting a urologist. Among those with a visit to a MOH, an additional month from diagnosis till the MOH visit was positively associated with PC mortality (HR: 1.03; p < 0.001) - i.e. a shorter time to a MOH visit was associated with PC survival. Similar results were obtained using the month of the urologist visit as the starting point (HR: 1.02; p < 0.001). Conclusions: Among A-PC patients who are referred to an oncologist, each additional month between diagnosis/urologist visit and the oncologist visit is associated with an increased relative risk of mortality.

[Table: see text]

Risk and cost of anthracycline-induced cardiotoxicity among breast cancer patients in the United States

1037

Background: Onset of anthracycline-induced cardiotoxicity is well documented. However, information regarding the time of onset varies depending on literature. The purpose of this study was to compare the risk of cardiotoxicity among three cohort groups: anthracycline-containing-chemotherapy (ACC), no-anthracycline-containing-chemotherapy (NACC), and no-chemotherapy (control) groups. Methods: A retrospective cohort study was designed using commercial managed care claims database. Adult subjects (≥18) diagnosed with breast cancer, between January 1, 2002 to December 31, 2005, (index-period) were followed for 24 months. Subjects with a previous cardiotoxic events (CE), breast cancer diagnosis, or anthracycline-use 12-months prior to index date were excluded. Index date was the first chemotherapy claim date for ACC and NACC and non-chemotherapy medication claim date for controls. Cohorts were matched by index date and year of birth. CE was defined based on ICD-9-CM and Healthcare Common Procedure Coding System codes. Risk of CE was evaluated using a logistic model with and without adjusting for confounders. Results: 21,106 subjects were classified as ACC (n = 3,428), NACC (n = 7,125), and controls (n = 10,553). NACC cohort was significantly (p < 0.01) older (mean age: 62 years ±12.5) compared to ACC (53±9.7) or control cohorts (59±12.5). ACC cohort had a higher (p < 0.01) average degree of comorbidity, (1.8±0.8) compared to NACC (1.6±0.9) or control (1.3±0.8) as measured by Charlson comorbidity-index. Higher rates of CE were found within the ACC group compared to NACC and controls as early as month 3 post index-date and remained consistent over 24 months. At month 12 post index-date, 14% (n = 485) of ACC and 5% (n = 381) of NACC had CE compared to 3% (n = 310) of controls. After adjusting for all baseline differences, the odds ratio of CE compared to controls was 3.98 (95% CI: 3.27–4.85), and 1.31 (95% CI: 1.11–1.54) for ACC and NACC cohorts, respectively. The total mean costs were $59,287, $20,528, and $11,600, among ACC, NACC, and control cohorts respectively. Conclusions: Compared to NACC and controls, ACC cohorts had significantly higher risk of cardiotoxic events and seen as early as month 3 post treatment initiation.

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Asthma severity categorization using a claims-based algorithm or pulmonary function testing

OBJECTIVES

This study was performed to determine whether pulmonary function test results would appreciably alter asthma severity categorization determined by an algorithm using information readily available in administrative databases.

METHODS

Patients 6 to 64 years of age with asthma diagnosed from 1999-2005, who had at least one pulmonary function test, were identified from a claims database of a medical group practice located in central Massachusetts. Asthma severity for these patients was categorized using information available in an administrative database (claims-based algorithm) and by percent predicted forced expiratory volume in 1 second (FEV(1)) or peak expiratory flow (PEF) abstracted from medical charts (pulmonary function test method). Gamma rank correlation index was used to measure the association between the two severity categorization methods. Total and asthma-related healthcare costs for each severity category were compared between the two different approaches.

RESULTS

There was a significant ordinal association between severity categorization with the two classification approaches (p = 0.0002). The pulmonary function test method resulted in more frequent mild categorizations and less frequent moderate and severe categorizations than the claims-based algorithm. In only 10.9% of patients did the pulmonary function test method result in a more severe asthma category than the claims-based algorithm. Patients with more severe asthma, determined by both methods, had higher total and asthma-related health care costs. Total and asthma-related health care costs were similar for each asthma severity categorization for the two classification approaches, except for asthma-related costs in the moderate severity categories.

CONCLUSION

The claims-based algorithm generally categorized patients as having more severe asthma than the approach using pulmonary function test results. Pulmonary function test results would have appreciably changed asthma severity categorization in only a small percent of patients. These findings add further support to the use of administrative database analyses for the evaluation of asthma care in large populations.

Will insomnia treatments produce overall cost savings to commercial managed-care plans? A predictive analysis in the United States

OBJECTIVE

Research indicates that insomnia may contribute significantly to healthcare costs; however, information on the effects of treatments on costs has not been thoroughly published. This study presents predictive models that forecast, from the perspective of commercial managed care, the effects of insomnia medications in reducing overall medical costs. The main objectives of this study were to predict the level of cost savings associated with insomnia treatments, illustrate the variation in outcomes given underlying model assumptions, and assist managed-care policy-makers with the evaluation of medications routinely administered for insomnia.

METHODS

Data on four primary-efficacy measures: wake after sleep onset (WASO), sleep efficiency (SE), sleep onset latency (SOL) and total sleep time (TST) were abstracted from published clinical trial data for eszopiclone, indiplon, low-dose trazodone, ramelteon, zaleplon, zolpidem and zolpidem extended-release. Change in per-patient per-year (PPPY) healthcare costs in a single claims database was calculated for subjects taking zolpidem, zaleplon and low-dose trazodone using generalized linear model (GLM) techniques, controlling for baseline demographics and baseline costs. Change in costs for emerging insomnia medications was forecasted by imputing efficacy values for these drugs into the regressions.

RESULTS

Using the accepted efficacy measure, WASO, zolpidem extended-release had the overall forecasted savings of -$1253 (CI: -$1404 to -$1404) PPPY compared to remaining treatments, whereas ramelteon cost an additional $348 (-$1280 to $584) PPPY. In three out of four cost-efficacy models, zolpidem extended-release had higher mean forecasted PPPY savings.

CONCLUSION

This study examined cost effects of existing and emerging insomnia medications using models integrating clinical literature and medical claims within a statistical framework. The use of a single database may limit generalizability and models only address a 1-year period. Results suggest treatments can offer health plans direct cost savings, with amounts sensitive to variable and efficacy measures, potentially limited by those variables available in the claims database. Compared to other evaluated treatments, zolpidem extended-release produced consistently higher predicted cost savings.

Retrospective characterization of Newcastle Disease Virus Antrim '73 in relation to other epidemics, past and present

In November 1973 Newcastle disease suddenly appeared in Northern Ireland, where the viscerotropic disease had not been seen in 3 1/2 years and the two Irelands had been regarded as largely disease free for 30 years. It was successfully controlled with only 36 confirmed affected layer flocks, plus 10 more slaughtered as 'dangerous contacts'. Contemporary investigations failed to reveal the source of the Irish epidemic. Using archival virus samples from most of the affected flocks, RT PCR was conducted with primers selected for all six NDV genes. Phylogenetic analyses of three genes, HN, M and F, confirmed vaccine as the cause of one of the outbreaks. The other six samples were identical and closely related to previous outbreaks in the United States and western Europe initiated by infected imported Latin American parrots. The probable cause of the epidemic followed from the importation from The Netherlands of bulk feed grains contaminated with infected pigeon faeces.

Antigens to viral capsid and non-capsid proteins are present in brain tissues and antibodies in sera of Theiler's virus-infected mice

Recombinant proteins to the LP, VP1, VP2, VP3, VP4, 2A, 2B, 2C, 3A, and 3D genes of Theiler's murine encephalomyelitis virus (TMEV) were generated and antibodies were produced against them for use in analysis of the TMEV epitopes responsible for eliciting the antibody responses observed during acute and chronic disease. Antibodies against recombinant VP1, VP2, and VP3 recognized the corresponding proteins from purified TMEV particles. In immunohistochemical analysis, antibodies against recombinant capsid (VP1, VP2, and VP3), and non-capsid (2A, 2C, 3A) proteins were reactive with PO-2D cells (astrocytes) infected with TMEV in vitro and with brain tissues of acutely infected mice. Antibodies against VP4, 2B, and 3D antigens were not reactive with corresponding viral proteins in infected astrocytes cells or brain tissues, but they reacted with TMEV precursor proteins produced during the early viral replication phase. Sera from SJL/J mice infected with TMEV acutely (14 days) and chronically (45 days) reacted with VP1, VP2, VP4, 2A, and 2C proteins. In an in vitro assay for neutralization, only anti-VP1 antibodies neutralized TMEV infection. These findings suggest that both capsid and non-capsid proteins of TMEV play a role in the immunopathology of the TMEV disease in the central nervous system.

Detection of a macrophage-specific antigen and the production of interferon gamma in chickens infected with Newcastle disease virus

Formalin-fixed, paraffin-embedded spleen and intestinal tissues were harvested at 2 days postinfection from 4-wk-old white rock chickens infected with five different strains of Newcastle disease virus (NDV). These tissues were examined for the presence of macrophage antigen expression, virus replication, and interferon gamma (IFN gamma) production. The five strains represented all three NDV pathotypes. Viral replication and IFN gamma, as determined by riboprobe in situ hybridization, were detected only in those chickens infected with velogenic viscerotropic NDV (VVNDV) strains. Macrophage antigen expression, an indicator of macrophage activation, was determined by immunohistochemistry with a macrophage-specific antibody, CVI-ChNL-68.1. Presence of macrophage antigen was most prominent in VVNDV-infected chickens. The distribution of this antigen within tissues was far more diffuse than the staining for viral mRNA. The presence of IFN gamma mRNA was detected in the spleen and intestinal lymphoid tissue of VVNDV-infected chickens. There was also increased macrophage antigen expression in the mesogen-infected birds, but it was less dramatic than in tissues from VVNDV-infected chickens. One of two lentogen-infected birds had evidence of increased macrophage antigen expression only in the spleen.

Molecular diagnosis of alcelaphine herpesvirus (malignant catarrhal fever) infections by nested amplification of viral DNA in bovine blood buffy coat specimens

A fragment of alcelaphine herpesvirus-1 (AHV-1; malignant catarrhal fever) DNA was subcloned into pUC 18 and sequenced. The subclone hybridized strongly to AHV-1 DNA, weakly to alcelaphine herpesvirus-2 (AHV-2) DNA, and not at all to DNA from bovine herpesvirus-1 (BHV-1; infectious bovine rhinotracheitis [IBR] virus), bovine herpesvirus-2 (BHV-2; bovine herpes mamillitis [BHM] virus), and bovine herpesvirus-4 (BHV-4; isolate DN599). A 2-stage (nested) polymerase chain reaction (PCR) diagnostic test was devised based on a portion of the subcloned AHV-1 DNA sequence. First and second stage amplified AHV-1 DNA targets were 487 and 172 base pairs (bp) in length, respectively. Unique Pvu II and Stu I restriction endonuclease cleavage sites confirmed the identity of amplified AHV-1 DNA. Five AHV-1 and 2 AHV-2 isolates were identically and specifically PCR positive. BHV-1, BHV-2, and BHV-4 viruses were negative by the same procedure. As little as 0.01 TCID50 AHV-1 was detected using the nested amplification procedure. Simple methods of buffy coat isolation from bovine blood were employed to prepare specimens for PCR. An AHV-1-infected calf was PCR positive from 3 to 77 days postinoculation (PI), with rising seroconversion first noted 14 days PI. The AHV-1 DNA sequence was 62% homologous to a portion of the Epstein-Barr virus genome. The nested PCR procedure may improve the viral diagnosis of clinical and subclinical alcelaphine herpesvirus infections.