Gary V. Walker

Disparities in Stage at Diagnosis, Treatment, and Survival in Nonelderly Adult Patients With Cancer According to Insurance Status

PURPOSE The purpose of this study was to determine the association of insurance status with disease stage at presentation, treatment, and survival among the top 10 most deadly cancers using the SEER database. PATIENTS AND METHODS A total of 473,722 patients age 18 to 64 years who were diagnosed with one of the 10 most deadly cancers in the SEER database from 2007 to 2010 were analyzed. A Cox proportional hazards model was used for multivariable analyses to assess the effect of patient and tumor characteristics on cause-specific death. RESULTS Overall, patients with non-Medicaid insurance were less likely to present with distant disease (16.9%) than those with Medicaid coverage (29.1%) or without insurance coverage (34.7%; P < .001). Patients with non-Medicaid insurance were more likely to receive cancer-directed surgery and/or radiation therapy (79.6%) compared with those with Medicaid coverage (67.9%) or without insurance coverage (62.1%; P < .001). In a Cox regression that adjusted for age, race, sex, marital status, residence, percent of county below federal poverty level, site, stage, and receipt of cancer-directed surgery and/or radiation therapy, patients were more likely to die as a result of their disease if they had Medicaid coverage (hazard ratio [HR], 1.44; 95% CI, 1.41 to 1.47; P < .001) or no insurance (HR, 1.47; 95% CI, 1.42 to 1.51; P < .001) compared with non-Medicaid insurance. CONCLUSION Among patients with the 10 most deadly cancers, those with Medicaid coverage or without insurance were more likely to present with advanced disease, were less likely to receive cancer-directed surgery and/or radiation therapy, and experienced worse survival.

Nomogram for Predicting the Benefit of Adjuvant Chemoradiotherapy for Resected Gallbladder Cancer

PURPOSE Although adjuvant chemoradiotherapy for resected gallbladder cancer may improve survival for some patients, identifying which patients will benefit remains challenging because of the rarity of this disease. The specific aim of this study was to create a decision aid to help make individualized estimates of the potential survival benefit of adjuvant chemoradiotherapy for patients with resected gallbladder cancer. METHODS Patients with resected gallbladder cancer were selected from the Surveillance, Epidemiology, and End Results (SEER) -Medicare database who were diagnosed between 1995 and 2005. Covariates included age, race, sex, stage, and receipt of adjuvant chemotherapy or chemoradiotherapy (CRT). Propensity score weighting was used to balance covariates between treated and untreated groups. Several types of multivariate survival regression models were constructed and compared, including Cox proportional hazards, Weibull, exponential, log-logistic, and lognormal models. Model performance was compared using the Akaike information criterion. The primary end point was overall survival with or without adjuvant chemotherapy or CRT. RESULTS A total of 1,137 patients met the inclusion criteria for the study. The lognormal survival model showed the best performance. A Web browser-based nomogram was built from this model to make individualized estimates of survival. The model predicts that certain subsets of patients with at least T2 or N1 disease will gain a survival benefit from adjuvant CRT, and the magnitude of benefit for an individual patient can vary. CONCLUSION A nomogram built from a parametric survival model from the SEER-Medicare database can be used as a decision aid to predict which gallbladder patients may benefit from adjuvant CRT.

Muddy Water? Variation in reporting receipt of breast cancer radiation therapy by population-based tumor registries

PURPOSE To evaluate, in the setting of breast cancer, the accuracy of registry radiation therapy (RT) coding compared with the gold standard of Medicare claims. METHODS AND MATERIALS Using Surveillance, Epidemiology, and End Results (SEER)-Medicare data, we identified 73,077 patients aged ≥66 years diagnosed with breast cancer in the period 2001-2007. Underascertainment (1 - sensitivity), sensitivity, specificity, κ, and χ(2) were calculated for RT receipt determined by registry data versus claims. Multivariate logistic regression characterized patient, treatment, and geographic factors associated with underascertainment of RT. Findings in the SEER-Medicare registries were compared with three non-SEER registries (Florida, New York, and Texas). RESULTS In the SEER-Medicare registries, 41.6% (n=30,386) of patients received RT according to registry coding, versus 49.3% (n=36,047) according to Medicare claims (P<.001). Underascertainment of RT was more likely if patients resided in a newer SEER registry (odds ratio [OR] 1.70, 95% confidence interval [CI] 1.60-1.80; P<.001), rural county (OR 1.34, 95% CI 1.21-1.48; P<.001), or if RT was delayed (OR 1.006/day, 95% CI 1.006-1.007; P<.001). Underascertainment of RT receipt in SEER registries was 18.7% (95% CI 18.6-18.8%), compared with 44.3% (95% CI 44.0-44.5%) in non-SEER registries. CONCLUSIONS Population-based tumor registries are highly variable in ascertainment of RT receipt and should be augmented with other data sources when evaluating quality of breast cancer care. Future work should identify opportunities for the radiation oncology community to partner with registries to improve accuracy of treatment data.

Population-based analysis of occult primary breast cancer with axillary lymph node metastasis

Single‐institution data suggest that treatment with radiation and axillary lymph node dissection (ALND) may be an appropriate alternative to mastectomy for T0N+ breast cancer. Population‐based multi‐institutional data supporting this approach are lacking.

Declining use of brachytherapy for the treatment of prostate cancer

PURPOSE To analyze the recent trends in the utilization of external beam radiation therapy (EBRT) and brachytherapy (BT) for the treatment of prostate cancer. METHODS AND MATERIALS Using the Surveillance, Epidemiology, and End Results (SEER) database, information was obtained for all patients diagnosed with localized prostate adenocarcinoma between 2004 and 2009 who were treated with radiation as local therapy. We evaluated the utilization of BT, EBRT, and combination BT+EBRT by the year of diagnosis and performed a multivariable analysis to determine the predictors of BT as treatment choice. RESULTS Between 2004 and 2009, EBRT monotherapy use increased from 55.8% to 62.0%, whereas all BT use correspondingly decreased from 44.2% to 38.0% (BT-only use decreased from 30.4% to 25.6%, whereas BT+EBRT use decreased from 13.8% to 12.3%). The decline of BT utilization differed by patient race, SEER registry, median county income, and National Comprehensive Cancer Network risk categorization (all p<0.001), but not by patient age (p=0.763) or marital status (p=0.193). Multivariable analysis found that age, race, marital status, SEER registry, median county income, and National Comprehensive Cancer Network risk category were independent predictors of BT as treatment choice (all p<0.001). Moreover, after controlling for all available patient and tumor characteristics, there was decreasing utilization of BT with increasing year of diagnosis (odds ratio for BT=0.920, 95% confidence interval: 0.911-0.929, p<0.001). CONCLUSIONS Our analysis reveals decreasing utilization of BT for prostate cancer. This finding has significant implications in terms of national health care expenditure.

Prospective randomized double-blind study of atlas-based organ-at-risk autosegmentation-assisted radiation planning in head and neck cancer

BACKGROUND AND PURPOSE Target volumes and organs-at-risk (OARs) for radiotherapy (RT) planning are manually defined, which is a tedious and inaccurate process. We sought to assess the feasibility, time reduction, and acceptability of an atlas-based autosegmentation (AS) compared to manual segmentation (MS) of OARs. MATERIALS AND METHODS A commercial platform generated 16 OARs. Resident physicians were randomly assigned to modify AS OAR (AS+R) or to draw MS OAR followed by attending physician correction. Dice similarity coefficient (DSC) was used to measure overlap between groups compared with attending approved OARs (DSC=1 means perfect overlap). 40 cases were segmented. RESULTS Mean ± SD segmentation time in the AS+R group was 19.7 ± 8.0 min, compared to 28.5 ± 8.0 min in the MS cohort, amounting to a 30.9% time reduction (Wilcoxon p<0.01). For each OAR, AS DSC was statistically different from both AS+R and MS ROIs (all Steel-Dwass p<0.01) except the spinal cord and the mandible, suggesting oversight of AS/MS processes is required; AS+R and MS DSCs were non-different. AS compared to attending approved OAR DSCs varied considerably, with a chiasm mean ± SD DSC of 0.37 ± 0.32 and brainstem of 0.97 ± 0.03. CONCLUSIONS Autosegmentation provides a time savings in head and neck regions of interest generation. However, attending physician approval remains vital.

Variation in insurance status by patient demographics and tumor site among nonelderly adult patients with cancer

In the United States, an estimated 48 million individuals live without health insurance. The purpose of the current study was to explore the Variation in insurance status by patient demographics and tumor site among nonelderly adult patients with cancer.

Pretreatment staging positron emission tomography/computed tomography in patients with inflammatory breast cancer influences radiation treatment field designs.

PURPOSE Positron emission tomography/computed tomography (PET/CT) is increasingly being utilized for staging of inflammatory breast cancer (IBC). The purpose of this study was to define how pretreatment PET/CT studies affected postmastectomy radiation treatment (PMRT) planning decisions for IBC. METHODS AND MATERIALS We performed a retrospective analysis of 62 patients diagnosed with IBC between 2004 and 2009, who were treated with PMRT in our institution and who had a staging PET/CT within 3 months of diagnosis. Patients received a baseline physical examination, staging mammography, ultrasonographic examination of breast and draining lymphatics, and chest radiography; most patients also had a bone scan (55 patients), liver imaging (52 patients), breast MRI (46 patients), and chest CT (25 patients). We compared how PET/CT findings affected PMRT, assuming that standard PMRT would target the chest wall, level III axilla, supraclavicular fossa, and internal mammary chain (IMC). Any modification of target volumes, field borders, or dose prescriptions was considered a change. RESULTS PET/CT detected new areas of disease in 27 of the 62 patients (44%). The areas of additional disease included the breast (1 patient), ipsilateral axilla (1 patient), ipsilateral supraclavicular (4 patients), ipsilateral infraclavicular (1 patient), ipsilateral IMC (5 patients), ipsilateral subpectoral (3 patients), mediastinal (8 patients), other distant/contralateral lymph nodes (15 patients), or bone (6 patients). One patient was found to have a non-breast second primary tumor. The findings of the PET/CT led to changes in PMRT in 11 of 62 patients (17.7%). These changes included additional fields in 5 patients, adjustment of fields in 2 patients, and higher doses to the supraclavicular fossa (2 patients) and IMC (5 patients). CONCLUSIONS For patients with newly diagnosed IBC, pretreatment PET/CT provides important information concerning involvement of locoregional lymph nodes, mediastinal lymph nodes, and unsuspected sites of distant metastasis. This information is important in the design of radiotherapy treatment fields and, therefore, we recommend that PET/CT be a component of initial staging for IBC.

Factors associated with radiation therapy incidents in a large academic institution

BACKGROUND This study evaluated factors associated with radiation therapy (RT) planning and delivery incidents at a large academic institution. METHODS AND MATERIALS The RT incidents (including near-misses) were recorded using an electronic incident reporting system from April 1, 2011 to April 30, 2013. Each incidents origin was categorized according to the step in the treatment process (simulation, physician prescription, treatment planning, scheduling, treatment delivery, and other) in which it occurred. The incident database was linked to the RT delivery (record and verify) database to evaluate the effect of various factors on the rate of RT incidents. RESULTS There were 189 reported RT incidents (including near-misses) among 326,448 fractions, of which there were 70 (37%) treatment planning incidents and 56 (30%) treatment delivery incidents. The rates of total incidents, planning incidents, and delivery incidents were 136.0, 50.4, and 40.3 per 10,000 patients, respectively. Logistic multivariate analysis showed that fewer work days from plan approval to treatment start, fewer fractions, higher number of prescription items, and longer beam duration were significantly associated with radiation planning incidents. Multivariate analysis also showed that first day of treatment, fewer fractions, higher number of prescription items, and longer beam duration were significantly associated with treatment delivery incidents; intensity modulated radiation therapy was associated with a lower rate of treatment delivery incidents. CONCLUSIONS More complicated radiation plans, fewer fractions, first day of treatment, and rushed processes were associated with higher risk of RT incidents. We hope that a national incident reporting database will lead to greater understanding of factors influencing the rate of RT incidents.

Decreasing Radiation Therapy Utilization in Adult Patients With Glioblastoma Multiforme A Population-Based Analysis

The purpose of this study was to assess what factors influence radiation therapy (RT) utilization in patients with glioblastoma and to ascertain how patterns of care have changed over time.