Proximity to Radiotherapy Center, Population, Average Income, and Health Insurance Status as Predictors of Cancer Mortality at the County Level in the United States.

PURPOSE: Sufficient radiotherapy (RT) capacity is essential to delivery of high-quality cancer care. However, despite sufficient capacity, universal access is not always possible in high-income countries because of factors beyond the commonly used parameter of machines per million people. This study assesses the barriers to RT in a high-income country and how these affect cancer mortality. METHODS: This cross-sectional study used US county-level data obtained from Center for Disease Control and Prevention and the International Atomic Energy Agency Directory of Radiotherapy Centres. RT facilities in the United States were mapped using Geographic Information Systems software. Univariate analysis was used to identify whether distance to a RT center or various socioeconomic factors were predictive of all-cancer mortality-to-incidence ratio (MIR). Significant variables (P ≤ .05) on univariate analysis were included in a step-wise backward elimination method of multiple regression analysis. RESULTS: Thirty-one percent of US counties have at least one RT facility and 8.3% have five or more. The median linear distance from a county's centroid to the nearest RT center was 36 km, and the median county all-cancer MIR was 0.37. The amount of RT centers, linear accelerators, and brachytherapy units per 1 million people were associated with all-cancer MIR (P < .05). Greater distance to RT facilities, lower county population, lower average income per county, and higher proportion of patients without health insurance were associated with increased all-cancer MIR (R-squared, 0.2113; F, 94.22; P < .001). CONCLUSION: This analysis used unique high-quality data sets to identify significant barriers to RT access that correspond to higher cancer mortality at the county level. Geographic access, personal income, and insurance status all contribute to these concerning disparities. Efforts to address these barriers are needed.

Incidence and extent of disease progression on MRI between surgery and initiation of radiotherapy in glioblastoma patients.

Background: A post-operative MRI (MRIpost-op) performed within 72 h is routinely used for radiation treatment planning in glioblastoma (GBM) patients, with radiotherapy starting about 4-6 weeks after surgery. Some patients undergo an additional pre-radiotherapy MRI (MRIpre-RT) about 2-6 weeks after surgery. We sought to analyze the incidence of rapid early progression (REP) between surgery and initiation of radiotherapy seen on MRIpre-RT and the impact on radiation target volumes. Methods: Patients with GBM diagnosed between 2018 and 2020 who had an MRIpost-op and MRIpre-RT were retrospectively identified. Criteria for REP was based on Modified RANO criteria. Radiation target volumes were created and compared using the MRIpost-op and MRIpre-RT. Results: Fifty patients met inclusion criteria. The median time between MRIpost-op and MRIpre-RT was 26 days. Indications for MRIpre-RT included clinical trial enrollment in 41/50 (82%), new symptoms in 5/50 (10%), and unspecified in 4/50 (8%). REP was identified in 35/50 (70%) of patients; 9/35 (26%) had disease progression outside of the MRIpost-op-based high dose treatment volumes. Treatment planning with MRIpost-op yielded a median undertreatment of 27.1% of enhancing disease and 11.2% of surrounding subclinical disease seen on MRIpre-RT. Patients without REP had a 38% median volume reduction of uninvolved brain if target volumes were planned with MRIpre-RT. Conclusion: Given the incidence of REP and its impact on treatment volumes, we recommend using MRIpre-RT for radiation treatment planning to improve coverage of gross and subclinical disease, allow for early identification of REP, and decrease radiation treatment volumes in patients without REP.

Radiation Therapy in Conjunction With Surgical Stabilization of Impending or Pathologic Fractures Secondary to Metastasis: Is There a Difference Between Single and Multifraction Regimens?

PURPOSE: Patients who undergo surgical stabilization for impending or pathologic fractures secondary to metastasis are often treated with radiation therapy to the involved site. We sought to retrospectively analyze outcomes from single versus multifraction regimens of radiation therapy in this setting. METHODS AND MATERIALS: From our institutional radiation database, we identified 87 patients between 2004 and 2016 who had an impending or pathologic fracture from metastatic disease and who underwent surgical fixation in conjunction with either neoadjuvant (within 5 weeks before surgery) or adjuvant (within 10 weeks after surgery) radiation therapy, representing 99 total treatment sites. Patients were included on the basis of intention to treat with bimodality therapy. Baseline patient characteristics were compared using 2-sided t tests and Fisher's exact tests. Cumulative incidence of local failure, reirradiation, and reoperation were calculated using the Fine-Gray method for competing risks. Freedom from complication was calculated using the Kaplan-Meier method. RESULTS: Baseline characteristics between the single (n = 52) and multifraction (n = 47) cohorts were similar with the exception of higher rates of synchronous bony metastasis (83% vs 60%, P = .01) and female patients (71% vs 43%, P = .004) in the single fraction cohort. There was no significant difference in overall survival between treatment groups. After a median follow-up of 13 months, there was no significant difference in the single and multifraction cohorts, respectively, in the 1-year cumulative incidence rates of local failure (4% vs 7%, P = .58), reirradiation (5% vs 4%, P = .95), reoperation (4% vs 0%, P = .30), or 1-year freedom from complication (90% vs 95%, P = .40). CONCLUSIONS: This is the first study comparing outcomes between single and multifraction radiation therapy in conjunction with surgical stabilization of an impending or pathologic fracture. We found no difference in outcomes between single and multifraction regimens in this setting. Given these findings, single fraction perioperative radiation therapy may be a viable treatment option in appropriately selected patients pending prospective validation of these findings.

Investigating association of perineural invasion on prostate biopsy with Gleason score upgrading at prostatectomy: A multi-institutional analysis.

BACKGROUND: The significance of perineural invasion (PNI) in prostate cancer (PC) is unclear. A recent report of patients with pT2N0R0 PC found that PNI at prostatectomy was independently associated with higher Gleason score and more diffuse prostatic disease. We aimed to test our hypothesis that PNI on prostate biopsy in pT2N0R0 patients is associated with increased Gleason score upgrading at prostatectomy. METHODS: We identified 2892 patients status post prostatectomy with pT2N0R0 PC from three institutions, diagnosed between 1 January 2008 and 31 December 2014. Multivariable logistic regression (MVA) was used to evaluate the association between prostate biopsy PNI status and surgical Gleason upgrading, while controlling for potential confounders. RESULTS: Of the 2892 patients identified, 14% had PNI on biopsy, of whom 21% had surgical Gleason upgrading, while 28% without PNI on biopsy had such upgrading (P < .01). On MVA, the odds ratio (OR) of surgical Gleason upgrading for patients with biopsy PNI relative to patients without biopsy PNI was 0.69 (P < .01). The variables associated with surgical Gleason upgrading were age ≤60 years (OR 1.22, P = .02) and preoperative PSA >4 ng/mL (OR 1.26, P = .02). CONCLUSIONS: In post-prostatectomy patients with favorable-risk PC, PNI on prostate biopsy was not associated with surgical Gleason score upgrading. This may be due to the association of PNI with more diffuse disease, leading to increased biopsy tumor yield and grading accuracy. These findings suggest that in this setting, biopsy PNI alone should not be a concern for more aggressive disease requiring pathologic confirmation or intervention. This may help guide treatment decision-making for men debating active surveillance, radiation, and surgery.

Using hospital medical record data to assess the accuracy of the SEER Los Angeles Cancer Surveillance Program for initial treatment of prostate cancer: a small pilot study.

PURPOSE: Treatment information from the Surveillance, Epidemiology, and End Result Program (SEER) cancer registries is increasingly being used for population-based cancer research; however, it may be incomplete for outpatient procedures and is not quality controlled. We sought to validate SEER information on initial treatment of prostate cancer by comparison to electronic medical record (EMR) review. METHODS: Patients diagnosed with prostate cancer between 1 January 2010 and 31 December 2014 in Los Angeles County who received treatment at our institution within 6 months of diagnosis were identified from the SEER registry. We reviewed the hospital EMR for these patients and identified initial treatment received within 6 months of diagnosis. We compared data reported to SEER data to our re-abstracted hospital EMR data (defined as the gold standard) to identify the completeness of SEER treatment data (sensitivity) and the accuracy of the SEER information (positive predictive value). RESULTS: Based on 266 eligible patients, SEER's sensitivity in capturing initial treatment was 95.9% (118/123) for prostatectomy, 95.8% (69/72) for no treatment, 87.5% (21/24) for radiation therapy, 68.3% (28/41) for active surveillance or watchful waiting, and 50.0% (2/4) for cryosurgery. The SEER positive predictive value was 100% for radiation therapy and cryosurgery, 97.5% (118/121) for radical prostatectomy, 82.3% (28/34) for active surveillance or watchful waiting, and 78.4% (69/88) for no treatment. CONCLUSION: The SEER data were highly sensitive and has a high positive predictive value for surgery and radiation therapy but underreported use of active surveillance. These results may assist researchers in understanding the strengths and weaknesses of using SEER prostate cancer treatment data.