Brain Metastasis Incidence and Patterns of Presentation After Definitive Treatment of Locally Advanced Non-Small Cell Lung Cancer: A Potential Argument for Brain Magnetic Resonance Imaging Surveillance.

Purpose: Brain metastases (BMs) are a common source of morbidity and mortality. Guidelines do not advise brain surveillance for locally advanced non-small cell lung cancer (LA-NSCLC). We describe the incidence, time to development, presentation, and management of BMs after definitive chemoradiotherapy (CRT). Methods and Materials: We reviewed records of patients with LA-NSCLC treated with CRT within the period from 2013 to 2020. Descriptive statistics were used to characterize the population and the Kaplan-Meier method was used to estimate time to BM. Fisher exact tests and Wilcoxon rank-sum tests were used to compare outcomes between symptomatic and asymptomatic patients. Results: A total of 219 patients were reviewed including 96 with squamous cell carcinoma, 88 with adenocarcinoma, and 35 with large cell/not otherwise specified (LC/NOS). Thirty-nine patients (17.8%) developed BMs: 35 (90%) symptomatic and 4 (10%) asymptomatic. The rate of BM was highest in LC/NOS (34.3%) and adenocarcinoma (23.9%). Ninety percent of BMs occurred within 2 years. All asymptomatic patients underwent stereotactic radiosurgery alone, compared with 40% of symptomatic patients (P = .04). Symptomatic patients were more likely to require hospitalization (65.7% vs 0%, P = .02), craniotomy (25.7% vs 0%, not significant), and steroids (91.4% vs 0%, P < .001). Cumulative BM volume was higher for symptomatic patients (4 vs 0.24 cm3, P < .001) as was median greatest axial dimension (2.18 vs 0.52 cm, P < .001). Conclusions: We identified a high rate of BMs, particularly in LC/NOS and adenocarcinoma histology NSCLC. The majority were symptomatic. These results provide rationale for post-CRT magnetic resonance imaging brain surveillance for patients at high risk of BM.

Stereotactic body radiotherapy for synchronous early stage non-small cell lung cancer.

INTRODUCTION: In patients with non-small cell lung cancer (NSCLC) who present with multiple pulmonary nodules, it is often difficult to distinguish metastatic disease from synchronous primary lung cancers (SPLC). We sought to evaluate clinical outcomes after stereotactic body radiotherapy (SBRT) alone to synchronous primary lesions. MATERIAL AND METHODS: Patients with synchronous AJCC 8th Edition Stage IA-IIA NSCLC and treated with stereotactic body radiation therapy (SBRT) to all lesions between 2009-2018 were reviewed. SPLC was defined as patients having received two courses of SBRT within 180 days for treatment of separate early stage tumors. In total, 36 patients with 73 lesions were included. Overall survival (OS), progression-free survival (PFS), cumulative incidence of local failure (LF), and regional/distant failure (R/DF) were estimated and compared with a control cohort of solitary early stage NSCLC patients. RESULTS: Median PFS was 38.8 months (95% CI 14.3-not reached [NR]); 3-year PFS rates were 50.6% (35.6-72.1). Median OS was 45.9 months (95% CI: 35.9-NR); 3-year OS was 63.0% (47.4-83.8). Three-year cumulative incidence of LF and R/DF was 6.6% (3.7-13.9) and 35.7% (19.3-52.1), respectively. Patients with SPLC were compared to a control group (n = 272) of patients treated for a solitary early stage NSCLC. There was no statistically significant difference in PFS (p = .91) or OS (p = .43). Evaluation of the patterns of failure showed a trend for worse cumulative incidence of R/DF in SPLC patients as compared to solitary early stage NSCLC (p = .06). CONCLUSION: SBRT alone to multiple lung tumors with SPLC results in comparable PFS, OS, and LF rates to a cohort of patients treated for solitary early stage NSCLC. Those with SPLC had non-significantly higher R/DF. Patients with SPLC should be followed closely for failure and possible salvage therapy.

Malignant Transformation of Molecularly Classified Adult Low-Grade Glioma.

PURPOSE: Malignant transformation (MT) of adult grade 2 glioma (low-grade glioma [LGG]) is associated with adverse survival. We sought to describe the incidence, outcomes, and risk factors for MT of molecularly classified LGG. METHODS AND MATERIALS: We reviewed a single-institutional database of adults who received a diagnosis of LGG with data allowing for molecular classification from 1980 to 2018 to evaluate time to MT and its associated risk factors. MT was defined as pathologic confirmation of grade 3-4 glioma and/or imaging characteristics consistent with MT by multidisciplinary consensus. RESULTS: Among the included 486 adults with molecularly classified LGG, median age was 39 years (range, 18-78), median tumor size was 3.9 cm (range, 0.3-13.0), and 262 (54%) were male. Molecular classification was IDHmut1p/19qcodel in 169 (35%), IDHmut1p/19qintact in 125 (26%), and IDHwt in 192 (40%) patients. Adjuvant management was observation in 246 (51%) patients, temozolomide alone in 82 (16%), radiation therapy alone in 63 (13%), and radiation therapy concurrent with temozolomide in 81 (17%). Temozolomide monotherapy was more likely to be given to IDHmut1p/19qcodel patients (P < .001). Median follow-up was 5.3 years. MT occurred in 84 (17%) patients, with a 5-year freedom from MT of 86% (95% confidence interval [CI], 82%-90%). Median overall survival after MT was 2.4 years (95% CI, 1.5-3.3) and was associated with molecular classification (P = .03) and grade at MT (P < .001). Factors associated with MT were male sex (hazard ratio [HR], 2.1; 95% CI, 1.2-3.6; P = .009), tumor size ≥5 cm (HR, 3.5; 95% CI, 2.0-6.2; P < .001), IDHmut1p/19qintact (HR, 2.7; 95% CI, 1.3-5.6; P = .009) or IDHwt classification (HR, 5.5; 95% CI, 2.5-11.8; P < .001), and adjuvant temozolomide monotherapy (HR, 3.8; 95% CI, 1.4-10.3; P = .008). CONCLUSIONS: MT of LGG has a poor prognosis associated with unfavorable molecular groups. Analysis of our large cohort identified adjuvant temozolomide monotherapy as the only modifiable risk factor for MT and provides the first clinical evidence of temozolomide-associated MT among molecularly classified adult LGG. This novel finding supplements our understanding of temozolomide-induced hypermutation and informs precision management of LGG.

Risk Factors for Progression Among Low-Grade Gliomas After Gross Total Resection and Initial Observation in the Molecular Era.

PURPOSE: To identify risk factors for progression-free survival (PFS) in the molecular era among patients with low-grade glioma (LGG) who undergo gross total resection (GTR) followed by initial observation. METHODS AND MATERIALS: We reviewed patients with World Health Organization grade 2 LGG treated at a single institution. We included only those who underwent magnetic resonance imaging (MRI)-confirmed GTR followed by initial observation. Molecular classification was obtained at either the time of diagnosis or pathology review. Cox proportional hazards regression, the Kaplan-Meier method, and the log-rank test were used. P values <.05 were considered statistically significant. RESULTS: We included 144 patients who underwent MRI-confirmed GTR between 1994 and 2014 followed by initial observation. Median age was 29 years (interquartile range [IQR], 18-41), median tumor size was 2.7 cm (IQR, 1.8-4.0), and median follow-up was 81 months (IQR, 36-132). Molecular classification was 13% IDH-mutant 1p19q-codeleted; 21% IDH-mutant 1p19q-intact; 39% IDH1-R132H-wildtype; and 28% undetermined. For the entire cohort, 5- and 10-year PFS and overall survival were 71% and 53%, and 98% and 90%, respectively. On multivariate analysis, factors associated with worse PFS included increasing age at diagnosis (hazard ratio [HR], 1.05; 95% CI, 1.00-1.09; P = .03), increasing preoperative tumor size (HR, 1.07; 95% CI, 1.04-1.10; P < .0001), and IDH-mutant 1p19q-intact classification (HR, 3.18; 95% CI, 1.15-8.74, P = .025). Median PFS for patients with IDH-mutant 1p19q-codeleted, IDH-mutant 1p19q-intact, and IDH1-R132H-wildtype tumors were 113 months, 56 months, and not reached, respectively. Molecular classification was significantly associated with PFS (P < .0001) but not overall survival (P = .20). CONCLUSIONS: Among patients with LGG who undergo MRI-confirmed GTR and initial observation in the molecular era, increasing age, increasing tumor size, and IDH-mutant 1p19q-intact classification are associated with worse PFS. Because tumor progression is associated with adverse health-related quality of life, these factors may aid clinicians and patients in the shared decision-making process regarding goals of surgery and timing of postoperative therapy. Further study is required to elucidate why IDH-mutant 1p19q-intact LGGs are at higher risk for early progression.

Hypofractionated Radiation Therapy for Localized Prostate Cancer: Executive Summary of an ASTRO, ASCO and AUA Evidence-Based Guideline.

PURPOSE: The aim of this guideline is to present recommendations regarding moderately hypofractionated (240-340 cGy per fraction) and ultrahypofractionated (500 cGy or more per fraction) radiation therapy for localized prostate cancer. METHODS AND MATERIALS: The American Society for Radiation Oncology convened a task force to address 8 key questions on appropriate indications and dose-fractionation for moderately and ultrahypofractionated radiation therapy, as well as technical issues, including normal tissue dose constraints, treatment volumes, and use of image guided and intensity modulated radiation therapy. Recommendations were based on a systematic literature review and created using a predefined consensus-building methodology and Society-approved tools for grading evidence quality and recommendation strength. RESULTS: Based on high-quality evidence, strong consensus was reached for offering moderate hypofractionation across risk groups to patients choosing external beam radiation therapy. The task force conditionally recommends ultrahypofractionated radiation may be offered for low- and intermediate-risk prostate cancer but strongly encourages treatment of intermediate-risk patients on a clinical trial or multi-institutional registry. For high-risk patients, the task force conditionally recommends against routine use of ultrahypofractionated external beam radiation therapy. With any hypofractionated approach, the task force strongly recommends image guided radiation therapy and avoidance of nonmodulated 3-dimensional conformal techniques. CONCLUSIONS: Hypofractionated radiation therapy provides important potential advantages in cost and convenience for patients, and these recommendations are intended to provide guidance on moderate hypofractionation and ultrahypofractionation for localized prostate cancer. The limits in the current evidentiary base-especially for ultrahypofractionation-highlight the imperative to support large-scale randomized clinical trials and underscore the importance of shared decision making between clinicians and patients.

Hypofractionated Radiation Therapy for Localized Prostate Cancer: Executive Summary of an ASTRO, ASCO, and AUA Evidence-Based Guideline.

PURPOSE: The aim of this guideline is to present recommendations regarding moderately hypofractionated (240-340 cGy per fraction) and ultrahypofractionated (500 cGy or more per fraction) radiation therapy for localized prostate cancer. METHODS AND MATERIALS: The American Society for Radiation Oncology convened a task force to address 8 key questions on appropriate indications and dose-fractionation for moderately and ultrahypofractionated radiation therapy, as well as technical issues, including normal tissue dose constraints, treatment volumes, and use of image guided and intensity modulated radiation therapy. Recommendations were based on a systematic literature review and created using a predefined consensus-building methodology and Society-approved tools for grading evidence quality and recommendation strength. RESULTS: Based on high-quality evidence, strong consensus was reached for offering moderate hypofractionation across risk groups to patients choosing external beam radiation therapy. The task force conditionally recommends ultrahypofractionated radiation may be offered for low- and intermediate-risk prostate cancer but strongly encourages treatment of intermediate-risk patients on a clinical trial or multi-institutional registry. For high-risk patients, the task force conditionally recommends against routine use of ultrahypofractionated external beam radiation therapy. With any hypofractionated approach, the task force strongly recommends image guided radiation therapy and avoidance of nonmodulated 3-dimensional conformal techniques. CONCLUSIONS: Hypofractionated radiation therapy provides important potential advantages in cost and convenience for patients, and these recommendations are intended to provide guidance on moderate hypofractionation and ultrahypofractionation for localized prostate cancer. The limits in the current evidentiary base-especially for ultrahypofractionation-highlight the imperative to support large-scale randomized clinical trials and underscore the importance of shared decision making between clinicians and patients.

Predictive factors on outcomes in metaplastic breast cancer.

PURPOSE: Metaplastic breast cancer (MBC) is a rare, aggressive variant of breast cancer, with limited data available regarding treatment and outcomes. This study aims to review patients with MBC treated at our tertiary care institution with an emphasis on the role of treatment modality and histologic classification. METHODS: With IRB-approval, we queried our pathology database for patients with MBC diagnosis. All cases were re-evaluated by dedicated breast pathologists and confirmed as MBC breast cancer. Patient demographics, clinical/pathologic histology, and treatment were analyzed with respect to outcomes including local-regional recurrence (LRR), distant metastasis (DM), and overall survival (OS). Univariate and multivariate Cox proportional hazards models were performed to evaluate the impact on outcomes. Kaplan-Meier methods estimated survival. RESULTS: We evaluated 113 patients with MBC diagnosed between 2002 and 2013. Median age was 61 years and median pathologic tumor size 2.5 cm; 76 (67%) were ER/PR/Her2 negative, 83 (74%) grade 3. Median follow-up was 38 months. 47 (42%) underwent breast conservation therapy (BCT), 66 (58%) had mastectomy, 61 (54%) underwent adjuvant radiation (RT), and 85 (75%) had chemotherapy. At 2 and 5 years, the LRR/DM/OS rates were 12%/15%/90% and 21%/35%/69%, respectively. On Cox regression analysis, only adjuvant RT correlated with reduced LRR [RR 3.1 (1.13-9.88), p = 0.027], while chemotherapy, type of surgery, and T-N stage did not. Only T-stage (p = 0.008) correlated with DM, however chemotherapy, RT, surgery type, and N-stage were not. Univariate analysis demonstrated histologic subtype did not significantly correlate with local (p = 0.54) or distant (p = 0.83) disease control. CONCLUSIONS: This study represents among the largest institutional experiences in the outcomes of MBC. At this time, there does not appear to be a clear histologic subset of MBC which has significantly different clinical outcomes from the other subtypes. Although limited in its sample size, this study shows RT remains important in local-regional control.

Taste and smell disturbances after brain irradiation: a dose-volume histogram analysis of a prospective observational study.

PURPOSE: Radiation-induced taste and smell disturbances are prevalent in patients receiving brain radiation therapy, although the mechanisms underlying these toxicities are poorly understood. We report the results of a single institution prospective clinical trial aimed at correlating self-reported taste and smell disturbances with radiation dose delivered to defined areas within the brain and nasopharynx. METHODS AND MATERIALS: Twenty-two patients with gliomas were enrolled on a prospective observational trial in which patients underwent a validated questionnaire assessing taste and smell disturbances at baseline and at 3 and 6 weeks after commencement of brain radiation therapy. Fourteen patients with glioblastoma, 3 patients with grade 3 gliomas, and 5 patients with low grade gliomas participated. Median dose to tumor volume was 60 Gy (range, 45-60 Gy). Dose-volume histogram (DVH) analysis was performed for specific regions of interest that were considered potential targets of radiation damage, including the thalamus, temporal lobes, nasopharynx, olfactory groove, frontal pole, and periventricular stem cell niche. The %v10 (percent of region of interest receiving 10 Gy), %v40, and %v60 were calculated for each structure. Data from questionnaires and DVH were analyzed using stepwise regression. RESULTS: Twenty of 22 patients submitted evaluable questionnaires that encompassed at least the entire radiation therapy course. Ten of 20 patients reported experiencing some degree of smell disturbance during radiation therapy, and 14 of 20 patients experienced taste disturbances. Patients reporting more severe taste toxicity also reported more severe toxicities with sense of smell (r(2) = 0.60, P < .006). Tumor location in the temporal lobe predicted for increased severity of taste toxicity (F3, 16 = 1.44, P < .06). The nasopharynx was the only structure in which the DVH data predicted the presence of radiation-induced taste changes (r(2) = 0.28, P < .02). CONCLUSIONS: Radiation-induced taste toxicity appears to be more common in temporal lobe tumors, and may be related to the dose received by the nasopharynx.

Neuroanatomical target theory as a predictive model for radiation-induced cognitive decline.

OBJECTIVE: In a retrospective review to assess neuroanatomical targets of radiation-induced cognitive decline, dose volume histogram (DVH) analyses of specific brain regions of interest (ROI) are correlated to neurocognitive performance in 57 primary brain tumor survivors. METHODS: Neurocognitive assessment at baseline included Trail Making Tests A/B, a modified Rey-Osterreith Complex Figure, California or Hopkins Verbal Learning Test, Digit Span, and Controlled Oral Word Association. DVH analysis was performed for multiple neuroanatomical targets considered to be involved in cognition. The %v10 (percent of ROI receiving 10 Gy), %v40, and %v60 were calculated for each ROI. Factor analysis was used to estimate global cognition based on a summary of performance on individual cognitive tests. Stepwise regression was used to determine which dose volume predicted performance on global factors and individual neurocognitive tests for each ROI. RESULTS: Regions that predicted global cognitive outcomes at doses <60 Gy included the corpus callosum, left frontal white matter, right temporal lobe, bilateral hippocampi, subventricular zone, and cerebellum. Regions of adult neurogenesis primarily predicted cognition at %v40 except for the right hippocampus which predicted at %v10. Regions that did not predict global cognitive outcomes at any dose include total brain volume, frontal pole, anterior cingulate, right frontal white matter, and the right precentral gyrus. CONCLUSIONS: Modeling of radiation-induced cognitive decline using neuroanatomical target theory appears to be feasible. A prospective trial is necessary to validate these data.