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ABSTRACT: OBJECTIVE. A subset of patients with stage IA and IB non-small cell lung cancer (NSCLC) is ineligible for surgical resection and undergoes radiation therapy. Radiofrequency ablation (RFA) and stereotactic body radiotherapy are newer potentially attractive alternative therapies. MATERIALS AND METHODS. We added RFA and stereotactic body radiotherapy treatment modules to a microsimulation model that simulates lung cancer's natural history, detection, and treatment. Natural history parameters were previously estimated via calibration against tumor registry data and cohort studies; the model was validated with screening study and cohort data. RFA model parameters were calibrated against 2-year survival from the Radiofrequency Ablation of Pulmonary Tumor Response Evaluation (RAPTURE) study, and stereotactic body radiotherapy model parameters were calibrated against 3-year survival from a phase 2 prospective trial. We simulated lifetime histories of identical patients with early-stage NSCLC who were ineligible for resection, who were treated with radiation therapy, RFA, or stereotactic body radiotherapy under a range of scenarios. From 5,000,000 simulated individuals, we selected a cohort of patients with stage I medically inoperable cancer for analysis (n = 2056 per treatment scenario). Main outcomes were life expectancy gains. RESULTS. RFA or stereotactic body radiotherapy treatment in patients with peripheral stage IA or IB NSCLC who were nonoperative candidates resulted in life expectancy gains of 1.71 and 1.46 life-years, respectively, compared with universal radiation therapy. A strategy where patients with central tumors underwent stereotactic body radiotherapy and those with peripheral tumors underwent RFA resulted in a gain of 2.02 life-years compared with universal radiation therapy. Findings were robust with respect to changes in model parameters. CONCLUSION. Microsimulation modeling results suggest that RFA and stereotactic body radiotherapy could provide life expectancy gains to patients with stage IA or IB NSCLC who are ineligible for resection.
American Journal of Roentgenology 05/2013; 200(5):1020-7. · 2.78 Impact Factor
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ABSTRACT: The natural history model underlying the MGH Lung Cancer Policy Model (LCPM) does not include the two-stage clonal expansion model employed in other CISNET lung models. We used the LCPM to predict numbers of U.S. lung cancer deaths for ages 30-84 between 1975 and 2000 under four scenarios as part of the comparative modeling analysis described in this issue. The LCPM is a comprehensive microsimulation model of lung cancer development, progression, detection, treatment, and survival. Individual-level patient histories are aggregated to estimate cohort or population-level outcomes. Lung cancer states are defined according to underlying disease variables, test results, and clinical events. By simulating detailed clinical procedures, the LCPM can predict benefits and harms attributable to a variety of patient management practices, including annual screening programs. Under the scenario of observed smoking patterns, predicted numbers of deaths from the calibrated LCPM were within 2% of observed over all years (1975-2000). The LCPM estimated that historical tobacco control policies achieved 28.6% (25.2% in men, 30.5% in women) of the potential reduction in U.S. lung cancer deaths had smoking had been eliminated entirely. The hypothetical adoption in 1975 of annual helical CT screening of all persons aged 55-74 with at least 30 pack-years of cigarette exposure to historical tobacco control would have yielded a proportion realized of 39.0% (42.0% in men, 33.3% in women). The adoption of annual screening would have prevented less than half as many lung cancer deaths as the elimination of cigarette smoking.
Risk Analysis 07/2012; 32 Suppl 1:S117-24. · 2.37 Impact Factor
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ABSTRACT: A randomized trial has demonstrated that lung cancer screening reduces mortality. Identifying participant and program characteristics that influence the cost-effectiveness of screening will help translate trial results into benefits at the population level.
Six U.S. cohorts (men and women aged 50, 60, or 70 years) were simulated in an existing patient-level lung cancer model. Smoking histories reflected observed U.S. patterns. We simulated lifetime histories of 500,000 identical individuals per cohort in each scenario. Costs per quality-adjusted life-year gained ($/QALY) were estimated for each program: computed tomography screening; stand-alone smoking cessation therapies (4-30% 1-year abstinence); and combined programs.
Annual screening of current and former smokers aged 50 to 74 years costs between $126,000 and $169,000/QALY (minimum 20 pack-years of smoking) or $110,000 and $166,000/QALY (40 pack-year minimum), when compared with no screening and assuming background quit rates. Screening was beneficial but had a higher cost per QALY when the model included radiation-induced lung cancers. If screen participation doubled background quit rates, the cost of annual screening (at age 50 years, 20 pack-year minimum) was below $75,000/QALY. If screen participation halved background quit rates, benefits from screening were nearly erased. If screening had no effect on quit rates, annual screening costs more but provided fewer QALYs than annual cessation therapies. Annual combined screening/cessation therapy programs at age 50 years costs $130,500 to $159,700/QALY, when compared with annual stand-alone cessation.
The cost-effectiveness of computed tomography screening will likely be strongly linked to achievable smoking cessation rates. Trials and further modeling should explore the consequences of relationships between smoking behaviors and screen participation.
Journal of thoracic oncology: official publication of the International Association for the Study of Lung Cancer 09/2011; 6(11):1841-8. · 4.55 Impact Factor
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ABSTRACT: Simulation modeling can synthesize data from single-arm studies of lung cancer screening and tumor registries to investigate computed tomography (CT) screening. This study estimated changes in lung cancer outcomes through 2005, had chest CT screening been introduced in 1990.
Hypothetical individuals with smoking histories representative of 6 US cohorts (white males and females aged 50, 60, and 70 years in 1990) were simulated in the Lung Cancer Policy Model, a comprehensive patient-level simulation model of lung cancer development, screening, and treatment. A no screening scenario corresponded to observed outcomes. We simulated 3 screening scenarios in current or former smokers with > or =20 pack-years as follows: 1-time screen in 1990; and annual, and twice-annually screenings beginning in 1990 and ending in 2005. Main outcomes were days of life between 1990 and 2005 and life expectancy in 1990 (estimated by simulating life histories past 2005).
All screening scenarios yielded reductions (compared with no screening) in lung cancer-specific mortality by 2005, with larger reductions predicted for more frequent screening. Compared with no screening, annual screening of ever-smokers with at least 20 pack-years of cigarette exposure provided ever-smokers with an additional 11 to 33 days of life by 2005, or an additional 3-10 weeks of (undiscounted) life expectancy. In sensitivity analyses, the largest effects on gains from annual screening were due to reductions in screening adherence and increased smoking cessation.
The adoption of CT screening, had it been available in 1990, might have resulted in a modest gain in life expectancy.
Cancer 12/2008; 113(12):3440-9. · 4.77 Impact Factor
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ABSTRACT: To retrospectively compare the frequency with which patients underwent diagnostic medical imaging procedures during episodes of outpatient medical care according to whether their physicians referred patients for imaging to themselves and/or physicians in their same specialty or to radiologists.
Institutional review board approval was not necessary for this HIPAA-compliant study. An insurance claims database from a large national employer-based health plan was obtained. Claims data from 1999-2003 were grouped into episodes of care for six conditions: cardiopulmonary disease, coronary and/or cardiac disease, extremity fracture, knee pain, intraabdominal malignancy, and stroke. For each condition, each referring physician's behavior was categorized as either "same-specialty referral" or "radiologist referral" on the basis of that physician's entire history of imaging referrals for the condition. The frequency with which patients underwent diagnostic medical imaging procedures during episodes of care was compared according to whether their physicians referred patients for imaging to themselves and/or same-specialty physicians or to radiologists. Rates were compared by using chi(2) tests, and logistic regression was used to compare utilization rates, with patient age and number of comorbidities as covariates.
For the conditions evaluated, physicians who referred patients to themselves or to other same-specialty physicians for diagnostic imaging used imaging between 1.12 and 2.29 times as often, per episode of care, as physicians who referred patients to radiologists (P < .005 for all comparisons). Adjusting for patient age and comorbidity, the likelihood of imaging was 1.196-3.228 times greater for patients cared forby same-specialty-referring physicians.
Same-specialty-referring physicians tend to utilize imaging more frequently than do physicians who refer their patients to radiologists. These results cannot be explained by differences in case mix (because analyses were performed within six specific conditions of interest), patient age, or comorbidity.
Radiology 12/2007; 245(2):517-22. · 5.73 Impact Factor
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ABSTRACT: To systematically review studies qualitatively to compare the risks (gastrointestinal [GI] and cardiovascular) and benefits (pain control) of cyclooxygenase-2 inhibitors (coxibs) relative to an alternative therapy of a nonselective nonsteroidal antiinflammatory drug (NSAID) combined with a proton-pump inhibitor (PPI) and explore circumstances when coxibs may be appropriate.
Relevant studies were identified through a search of MEDLINE (Ovid Technologies, 1985-November 2005; English language, clinical trial), PubMed (1985-November 2005; English language, clinical trial, humans), and the Cochrane Collaboration using the terms selective COX-2 inhibitors and coxibs, as well as the various chemical names for specific coxib agents. Studies that compared a coxib with a nonselective NSAID and provided data concerning our outcomes of interest were included and categorized by the outcome variable, as well as by the specific coxib studied.
The majority of the numerous studies that evaluated pain as an endpoint showed no difference between coxib and nonselective NSAID therapy. However, while limited, preliminary safety data regarding the effects of both classes on the upper and lower GI tract suggest coxib superiority. Although coxibs are associated with an increased risk of cardiovascular adverse events (CVEs) compared with placebo, this effect has not been conclusively shown compared with nonselective NSAIDs. Currently, coxib therapy is more expensive than combination therapy using a nonselective NSAID plus a PPI.
Compared with combination therapy including a nonselective NSAID and PPI, coxibs provide equivalent pain control and may have a lower GI tract complication profile, but at an unknown increased risk of CVEs and a greater financial cost. Coxib therapy may be an appropriate treatment for chronic pain in select patients with higher risks of GI complications, lower risk of CVEs, and in whom greater cost is not a restraint.
Annals of Pharmacotherapy 07/2006; 40(6):1052-63. · 2.13 Impact Factor
