Prognostic impact of biologically equivalent dose in stereotactic body radiotherapy for renal cancer.

Purpose /Objectives Materials/Methods: The National Cancer Database (NCDB) was queried (2004-2017) for patients with RCC who did not have surgical resection but received definitive SBRT. Kaplan-Meier analysis with log-rank test was used to evaluate overall survival (OS). Univariable (UVA) and multivariable (MVA) analysis were conducted using cox proportional hazard models to determine prognostic factors for OS. Results: A total of 344 patients with median age 77 (IQR 70-85) were included in this study. Median BED3 was 180 Gy (IQR 126.03-233.97). Median OS was 90 months in the highest quartile compared to 36-52 months in the lower three quartiles (p < 0.01). On UVA, the highest BED3 quartile was a positive prognostic factor (HR 0.67, p < 0.01 CI 0.51-0.91) while age, tumor size, T-stage, metastasis, renal pelvis location, and transitional cell histology were negative factors. On MVA, the highest BED3 quartile was remained significant (HR 0.69, p = 0.02; CI 0.49-0.95) as a positive factor, while age, metastasis were negative factors. Conclusion: Higher BED may be associated with improved OS. Prospective investigation is needed to clearly define optimal BED for SBRT used to treat RCC.

Prognostic Effect of Systemic Therapy and Radiation Therapy in Stage I Nodal Marginal Zone Lymphoma.

PURPOSE: Nodal marginal zone lymphoma (NMZL) localized to a single lymphatic region (ie, stage I) is a relatively rare diagnosis. Current guidelines permit these patients to be either observed or treated with systemic therapy (ST), radiation therapy (RT), or both modalities. The prognostic effect of ST or RT compared with observation has not been established. The purpose of this study was to assess the prognostic effect of therapy in stage I NMZL. METHODS AND MATERIALS: The National Cancer Database was queried (2004-2018) for all patients with stage I NMZL. Patients were stratified based on treatment received. Propensity score matching (PSM) was performed overall and for each disease site to create 1:1 matched cohorts of patients who received RT and those who did not. Kaplan-Meier analysis evaluated overall survival (OS). Univariable (UVA) and multivariable Cox proportional hazard analyses identified clinical and treatment factors prognostic for OS. Subset analysis excluded patients deceased within 1 month of diagnosis to account for immortal time bias. RESULTS: A total of 3201 patients (median age 67) met inclusion criteria. A total of 1042 patients (33%) were head/neck/face, 208 (7%) intrathoracic, 613 (19%) intra-abdominal, 382 (12%) axilla/upper extremity, 292 (9%) inguinal/lower extremity, 86 (3%) pelvic, and 578 (18%) unspecified. A total of 1562 patients (49%) received no treatment, 721 (23%) received ST alone, 799 (25%) received RT alone, and 119 (4%) received both ST and RT. After PSM, ST was not prognostic on UVA while RT was prognostic on both UVA and multivariable analysis. After PSM, the 5-year OS was 84% for those who received RT and 79% for those who did not (P = .026). On subset analysis, these findings remained statistically significant for the head/neck/face cohort and the axilla/upper extremity cohort. After accounting for immortal time bias and performing PSM on this subset, the 5-year OS was 82% for those who received RT and 77% for those who did not (P = .047). CONCLUSIONS: In the overall cohort, RT improved OS compared with no RT, and ST was not a factor associated with OS. A radiation oncologist should be consulted for all patients with stage I NMZL for multidisciplinary decision making.

Role of 21-Gene Recurrence Score in Predicting Prognostic Benefit of Radiation Therapy After Breast-Conserving Surgery for T1N0 Breast Cancer.

PURPOSE: The 21-gene RT-PCR recurrence score (RS) is performed in patients with hormone receptor-positive (ER+, PR+), human epidermal growth factor receptor 2 (HER2)-negative, N0 breast cancer to determine which patients will likely benefit from chemotherapy after breast-conserving surgery (BCS). The purpose of this study was to evaluate whether the RS can predict for patients likely to benefit from radiation therapy (RT) after BCS. METHODS AND MATERIALS: The National Cancer Database was queried (2004-2017) for female patients with pT1N0 ER+ PR+ HER2-negative breast cancer treated with BCS who had an available RS. Patients were stratified based on their RS (low risk [LR], 1-10; intermediate risk [IR], 11-25; high risk [HR], 26-100). For each RS cohort, propensity score matching was conducted to create 1:1 matched cohorts of patients who received RT and patients who did not. Kaplan-Meier analysis evaluated overall survival (OS). Univariable and multivariable (MVA) Cox proportional hazard analysis identified clinical and treatment factors prognostic for OS. RESULTS: A total of 79,040 patients met the selection criteria: 18,823 in the LR cohort, 52,341 in the IR cohort, and 7876 in the HR cohort. A total of 92% of patients received RT: 91% in the LR cohort, 93% in the IR cohort, and 92% in the HR cohort. After propensity score matching, the 5-year OS in the LR cohort was 95% for those who received RT and 93% for those who did not (P = .184). In the IR cohort, the 5-year OS was 95% for those who received RT and 93% for those who did not (P = .001). In the HR cohort, the 5-year OS was 95% for those who received RT and 84% for those who did not (P < .001). MVA demonstrated that RT was a positive prognostic factor for OS in both the IR cohort (P = .001) and HR cohort (P < .001). On MVA in the LR cohort, RT (P = .186) was not predictive of improved OS. CONCLUSIONS: An OS benefit was observed with the use of RT in patients with IR or HR RS but not in patients with LR RS. Future prospective evaluation is warranted.

Renal function in abdominal neuroblastoma patients undergoing proton radiotherapy.

BACKGROUND: The purpose of this study is to analyze renal function outcomes in abdominal neuroblastoma patients undergoing proton therapy (PT). PROCEDURE: From 2011 to 2019, two single-institution Institutional Review Board-approved protocols prospectively enrolled neuroblastoma patients for data collection. To assess renal function, serum creatinine (Cr), blood urea nitrogen (BUN), and creatinine clearance (CrCl) before proton therapy (pre-PT) were compared with the values at last follow-up. RESULTS: A total of 30 children with abdominal neuroblastoma with median age 3.5 years (range, 0.9-9.1) at time of PT were included in this study. All patients underwent chemotherapy and resection of primary tumor prior to PT. Two patients required radical nephrectomy. Median follow-up after PT was 35 months. Mean dose to ipsilateral and contralateral kidney was 13.9 and 5.4 Gy, respectively. No patients developed hypertension or renal dysfunction during follow-up. There was no statistically significant change in serum BUN (p = .508), CrCl (p = .280), or eGFR (p = .246) between pre-PT and last follow-up. CONCLUSION: At a median follow-up of almost 3 years, renal toxicity was uncommon after PT. Longer follow-up and larger patient cohort data are needed to further assess impact of PT on renal function in this population.

Prognostic Impact of Radiation Therapy in Pure Mucinous Breast Carcinoma.

PURPOSE: Pure Mucinous breast carcinoma (PMBC) is an invasive breast cancer with favorable prognosis. While pathology-specific guidelines exist for PMBC regarding adjuvant chemotherapy and endocrine therapy, no recommendations exist regarding locoregional treatment based on tumor histology. Prognostic impact of radiotherapy for patients with PMBC remains unclear. MATERIALS AND METHODS: The National Cancer Database was queried (2004-2017) for patients with pN0M0 PMBC who underwent lumpectomy. Chi-square testing compared categorical frequencies between patients who received radiotherapy versus those who did not. Propensity score matching created a 1:1 matched cohort of patients who received radiotherapy and patients who didn't. Kaplan-Meier analysis evaluated overall survival (OS). Cox proportional hazard analyses identified clinical and treatment factors prognostic for OS. RESULTS: 17,259 patients met selection criteria; 11,087 (74%) received radiotherapy while 3852 (26%) did not. After PSM, radiotherapy (HR 0.629; 95% CI 0.531-0.746), endocrine therapy (HR 0.676; 95% CI 0.567-0.805), black race (HR 0.703; 95% CI 0.498-0.991), and private insurance (HR 0.184; 95% CI 0.078-0.432) were favorable prognostic factors on multivariate Cox regression analysis while age ≥ 70 years (HR 2.668; 95% CI 1.903-3.740), tumor size > 20 mm (HR 1.964; 95% CI 1.613-2.391), and CDCC score > 0 (HR 1.770; 95% CI 1.474-2.126) were unfavorable prognostic factors. After PSM, 5-year OS was 86% for those who received radiotherapy and 81% for those who did not (P < .001). CONCLUSION: This is the largest study to date on PMBC and the prognostic impact of adjuvant radiotherapy. Radiotherapy is associated with a survival advantage, suggesting omission of radiotherapy is not warranted.

21-Gene recurrence score predictive for prognostic benefit of radiotherapy in patients age ≥ 70 with T1N0 ER/PR + HER2- breast cancer treated with breast conserving surgery and endocrine therapy.

PURPOSE: Based on the results of the Cancer and Leukemia Group B (CALGB) 9343 trial, patients age ≥70 with T1N0 hormone receptor positive (ER/PR+), human epidermal growth factor receptor-2 negative (HER2-) breast cancer who are treated with breast conserving surgery (BCS) and endocrine therapy (ET) are candidates for omission of radiotherapy (RT). Because the CALGB 9343 trial did not stratify based on recurrence score (RS) test (Oncotype Dx), we conducted the present retrospective study to determine whether RS is predictive of who may benefit from RT following BCS in this cohort. MATERIALS AND METHODS: The National Cancer Database (NCDB) was queried (2004-2017) for patients age ≥ 70 with pT1N0 ER+/PR + HER2- breast cancer treated with BCS and ET. Patients were stratified based on their RS (low risk [LR] = 1-10, intermediate risk [IR] = 11-25, high risk [HR] = 26-99). Propensity score matching (PSM) created 1:1 matched cohorts of patients who received radiotherapy and those who did not. Kaplan-Meier analysis evaluated overall survival (OS). Univariable (UVA) and multivariable (MVA) Cox proportional hazard analyses identified clinical and treatment factors prognostic for OS. RESULTS: A total of 11,891 patients met the selection criteria: 3364 in the LR cohort, 7305 in the IR cohort, and 1222 in the HR cohort. A total of 79 % received RT: 77 % in the LR cohort, 79 % in the IR cohort, and 85 % in the HR cohort. Because PSM could not be efficiently performed in the HR cohort alone, the IR and HR cohort were merged (IRHR) for matching. After PSM, the 5-year OS in the LR cohort was 91 % for those who received RT and 89 % for those who did not (p = 0.605). In the IRHR cohort, the 5-year OS was 91 % for those who received RT and 87 % for those who did not (p = 0.003). On MVA in the LR cohort, RT (p = 0.727) was not predictive of improved OS. On MVA in the IRHR cohort, RT (p = 0.010) was a positive prognostic factor for OS. CONCLUSION: In this older cohort of patients, there is an OS benefit with the use of RT in patients with IRHR RS but not in patients with LR RS. Pending prospective evaluation, assessment of RS in this older subset of patients is recommended with consideration of RT when RS is ≥11.

Contemporary trends in management of uveal melanoma.

Purpose: In the management of uveal melanoma, eye plaque brachytherapy (EPBT) has replaced enucleation as the standard of care for small size tumors that require treatment, and for medium size tumors. In the modern era, EPBT is being utilized more frequently for certain large tumors as well. While there is prospective randomized evidence to support utilization of EPBT for tumors of appropriate dimensions, it is unclear what the actual practice patterns are across the United States. The purpose of this publication was to look at contemporary trends in the management of uveal melanoma across the United States to determine whether practices are appropriately adopting EPBT, and to investigate demographic and socio-economic factors that might be associated with deviations from this standard of care. Material and methods: The National Cancer Database was queried (2004-2015) for patients with uveal melanoma. Data regarding tumor characteristics and treatment were collected. Two-sided Pearson χ2 test was used to compare categorical frequencies between patients who received globe preserving treatments vs. those who received enucleation. Multivariable logistic regression modeling was used to determine characteristics predictive for receiving enucleation. Results: The enucleation rate for small/medium tumors (≤ 10 mm apical height and ≤ 16 mm basal diameter) decreased from 20% in 2004 to 10% in 2015. The EPBT rate for large tumors increased from 30% in 2004 to 45% in 2015. Numerous demographic and socio-economic factors were found to be associated with higher rates of enucleation. Conclusions: The overall trend across the nation is a decreased enucleation rate for small/medium tumors, and an increased EPBT rate for large tumors. A fraction of patients who should be candidates for EPBT are instead receiving enucleation, and in this study, we have shown that certain adverse demographic factors are associated with this.

DMSA-SPECT: A Novel Approach to Nephron Sparing SBRT for Renal Cell Carcinoma.

PURPOSE: Stereotactic body radiation therapy (SBRT) treatment planning for renal cell carcinoma requires accurate delineation of tumor from normal tissue due to the radiosensitivity of normal renal cortical tissue. Tc-99m dimercapto succinic acid (DMSA) renal imaging is a functional imaging technique that precisely differentiates normal renal cortical tissue from tumor. There are no prior publications reporting using this imaging modality for SBRT treatment planning. METHODS AND MATERIALS: A 59-year-old female with stage IV renal cell carcinoma progressed on systemic therapy and was dispositioned to primary cytoreduction with SBRT. She had baseline renal dysfunction and her tumor was 9 cm without clear delineation from normal tissue on conventional imaging. DMSA-single-photon emission computerized tomography (SPECT)/computed tomography (CT) was used for treatment planning. RESULTS: DMSA-SPECT/CT precisely delineated normal renal cortical tissue from tumor. Three months after treatment, labs were stable and DMSA-SPECT/CT was unchanged. The treated lesion had markedly decreased positron emission tomography avidity. CONCLUSIONS: DMSA-SPECT or SPECT/CT can be incorporated into radiation therapy planning for renal lesions to improve target delineation and better preserve renal function.

Time Interval to Initiation of Whole-Brain Radiation Therapy in Patients With Small Cell Lung Cancer With Brain Metastasis.

PURPOSE: Patients with small cell lung cancer (SCLC) who have brain metastases require whole-brain radiation therapy (WBRT). When there is no emergent indication for WBRT, patients may receive systemic therapy first and WBRT afterward. In scenarios when systemic therapy is initiated first, it has not been previously investigated whether delaying WBRT is harmful. METHODS AND MATERIALS: The National Cancer Database was queried (2004-2016) for patients with SCLC with brain metastases who received 30 Gy in 10 fractions of WBRT. Patients were divided into groups based on whether they received early WBRT (3-14 days after initiation of chemotherapy) or late WBRT (15-90 days after initiation of chemotherapy). Demographic and clinicopathologic categorical variables were compared between those who had early WBRT (3-14 days) and those who had late WBRT (15-90 days). Factors predictive for late WBRT were determined. Overall survival (OS), which was defined as days from diagnosis to death, was evaluated and variables prognostic for OS were determined. RESULTS: A total of 1082 patients met selection criteria; 587 (54%) had early WBRT and 495 (46%) received late WBRT. Groups were similarly distributed aside from days from initiating chemotherapy to initiating WBRT (P < .001). The early WBRT group had a median of 7 days (interquartile range [IQR], 5-10 days) from initiating chemotherapy to initiating WBRT and the late WBRT group had a median of 34 days (IQR, 21-57 days). On binary logistic regression analysis, a longer time interval between diagnosis and the start of systemic therapy was predictive for later WBRT. Median OS was 8.7 months for early WBRT and 7.5 months for late WBRT (hazard ratio [HR], 1.165; P = .008). Early WBRT (P = .02), female sex (P = .045), and private insurance (P = .04) were favorable prognostic factors for OS on multivariable analysis, whereas older age (P = .006) was an unfavorable prognostic factor. CONCLUSIONS: Patients with SCLC and brain metastases who received early WBRT were found to have a modest improvement in OS compared with patients who received late WBRT. These findings suggest that early WBRT should be offered to patients who have brain metastases, even in the absence of an indication for emergent WBRT.

Postmastectomy radiation therapy following pathologic complete nodal response to neoadjuvant chemotherapy: A prelude to NSABP B-51?

PURPOSE: The utility of post-mastectomy radiotherapy (PMRT) in women with a nodal complete response (CRn) to neoadjuvant chemotherapy (NAC) is unknown. The NSABP B-51 trial is evaluating this question, but has not reported results thus far. Therefore, we sought to answer this question with the National Cancer Database. METHODS: The National Cancer Database was queried for women with cT1-4N1-3M0 breast cancer who had undergone NAC and were ypN0 upon mastectomy. Statistics included multivariable logistic regression, Kaplan-Meier overall survival (OS) analysis, Cox proportional hazards modeling, and construction of forest plots. RESULTS: Of 14,690 women, 10,092 (69%) underwent adjuvant PMRT and 4598 (31%) did not. The median follow-up was 55.6 months. In all patients, the 10-year OS was 76.3% for PMRT and 78.6% without (p = 0.412). There were no notable effects of PMRT on OS based on age or the axillary management (number of nodes removed). Specifically, in the NSABP B-51 population of cT1-3 cN1 patients, the 10-year OS was 82.6% for PMRT and 80.0% without (p = 0.250). PMRT benefitted women with increasing cT stage (i.e. cT3-4), increasing ypT stages (with the exception of ypT4 potentially owing to small sample sizes), and cN3 cases (p < 0.05 for all). CONCLUSIONS: In the absence of published results from NSABP B-51, this assessment of over 14,000 women from a contemporary US database revealed that PMRT may be most useful for a "moderately-high" risk group - women with more advanced primary and/or nodal disease at diagnosis, yet with tumor biology favorable enough that the disease does not progress or remain stable after NAC. The OS findings notwithstanding, this study cannot exclude potential differences between groups in recurrence-free survival, which is the primary endpoint of NSABP B-51, While the results of the NSABP B-51 will confirm optimal management for patients with limited nodal disease having a CRn following NAC, the present results suggest PMRT should remain the standard of care for more advanced disease than NSABP B-51 eligibility criteria.

Solitary Leptomeningeal Recurrence From Prostate Adenocarcinoma After Treatment With Cytotoxic Gene Therapy, Radiation Therapy, and Androgen Deprivation Therapy.

PURPOSE: Leptomeningeal disease in prostate adenocarcinoma is very rare. Solitary leptomeningeal recurrence from prostate adenocarcinoma has only been previously reported once in the published literature. METHODS AND MATERIALS: A 63-year-old man with high-risk prostate cancer was treated in a phase I-II trial with androgen deprivation, radiation therapy, and cytotoxic gene therapy. He initially had biochemical control but experienced solitary leptomeningeal recurrence 47 months after diagnosis. RESULTS: He received androgen deprivation, radiation therapy to the lumbar and sacral spine, and stereotactic radiosurgery to 3 intracranial foci of disease. He died 14 months after leptomeningeal recurrence. Autopsy showed diffuse spinal leptomeningeal disease, leptomeningeal based intracranial lesions, and no other metastasis. CONCLUSIONS: The cause for solitary leptomeningeal recurrence in this patient is unknown. Although there may be many possible mechanisms, we speculate that it could be related to his initial treatment with cytotoxic gene therapy along with radiation therapy and androgen deprivation.

Adaptive Radiation Therapy for Intact Thymoma: An Illustrative Report.

BACKGROUND/AIM: Adaptive radiation therapy (ART) is a technique capable of reducing radiation dose to normal tissue without compromising local control. For potentially resectable thymoma, induction therapy is standard of care. Because large disease volume is common in this context, ART has been suggested to reduce toxicity from induction chemoradiation. This has not been previously illustrated in the literature. CASE REPORT: A 38-year-old man with initially unresectable thymoma was treated with induction chemoradiation including cisplatin and etoposide. He received 45 Gy in 25 fractions and ART was utilized to shrink the radiotherapy field for the final 10 fractions. RESULTS: Thymectomy showed Masaoka stage III disease with negative margins. He experienced no treatment-related toxicity and has no evidence of disease 8 years after diagnosis. CONCLUSION: Induction chemoradiotherapy with ART appears to be feasible, safe, and efficacious for locally advanced intact thymoma.

Real-world evaluation of the impact of radiotherapy and chemotherapy in elderly patients with glioblastoma based on age and performance status.

BACKGROUND: This retrospective study investigated the impact of, in addition to age, the management and outcomes of elderly patients with glioblastoma (GBM). METHODS: The National Cancer Database was queried between 2004 and 2015 for GBM patients age 60 years and older. Three age groups were created: 60 to 69, 70 to 79, and 80 years and older, and 4 age/KPS groups: "age ≥ 60/ KPS < 70" (group 1), "age 60 to 69/KPS ≥ 70" (group 2), "age 70 to 79/KPS ≥ 70" (group 3), and "age ≥ 80/KPS ≥ 70" (group 4). Multivariable (MVA) modeling with Cox regression determined predictors of survival (OS), and estimated average treatment effects analysis was performed. RESULTS: A total of 48 540 patients with a median age of 70 years (range, 60-90 years) at diagnosis, and a median follow-up of 6.8 months (range, 0-151 months) were included. Median survival was 5.0, 15.2, 9.6, and 6.8 months in groups 1, 2, 3, and 4, respectively (P < .001). On treatment effects analysis, all groups survived longer with combined chemotherapy (ChT) and radiation therapy (RT), except group 1, which survived longer with ChT alone (P < .001). RT alone was associated with the worst OS in all groups (P < .01). Across all groups, predictors of worse OS on MVA were older age, lower KPS, White, higher comorbidity score, worse socioeconomic status, community treatment, tumor multifocality, subtotal resection, and no adjuvant treatment (all P < .01). CONCLUSIONS: In elderly patients with newly diagnosed GBM, those with good KPS fared best with combined ChT and RT across all age groups. Performance status is a key prognostic factor that should be considered for management decisions in these patients.

Staged Stereotactic Radiosurgery Decreases Symptomatic Radionecrosis in Large Brain Metastasis.

BACKGROUND: Limited brain metastasis is treated definitively with stereotactic radiosurgery when surgical resection is not indicated. Although this has historically been performed in a single fraction, multi-fraction approaches such as fraction radiosurgery (FSRS) and staged radiosurgery (SSRS) have been recently examined as alternative approaches for larger lesions to permit better tumor control without increased toxicity. CASE REPORT: We present the case of a patient who developed symptomatic radionecrosis in two brain metastasis, 2.3 cm and 2.1 cm in size, which were treated with 18 Gy in one fraction, but no radionecrosis in a 3.3 cm lesion treated in two fractions of 15 Gy nor in two punctate lesions that were treated in one fraction of 20 Gy. Although she did not respond to steroids, she responded to bevacizumab symptomatically and on neuroimaging. CONCLUSION: Congruent with other recent studies, our report suggests that large brain metastasis should be considered for FSRS/SSRS.

Prognostic impact of radiation therapy in tubular carcinoma of the breast.

PURPOSE: Tubular carcinoma (TC) is an invasive breast cancer with favorable prognosis. While pathology-specific guidelines exist for TC regarding adjuvant chemotherapy and endocrine therapy, no recommendations exist regarding locoregional treatment based on tumor histology. Prognostic impact of radiotherapy for patients with TC remains unclear. MATERIALS AND METHODS: The National Cancer Database was queried (2004-2015) for patients with pN0M0 TC who underwent lumpectomy. Chi-square testing compared categorized variables between those who did and did not receive radiotherapy. Kaplan-Meier analysis evaluated overall survival (OS). Cox proportional hazard analysis identified variables prognostic for OS. Patients were divided into age cohorts ≤60 years and >60 years. Propensity score matching (PSM) was utilized to create similar cohorts. RESULTS: 9705 patients met selection criteria; 6182 (75.1%) received radiotherapy while 2045 (24.9%) did not. After PSM, radiotherapy (HR 0.582; 95% CI 0.494-0.686) and endocrine therapy (HR 0.737; 95% CI 0.623-0.872) were favorable prognostic factors on multivariate Cox regression analysis while age > 60 years (HR 5.131; 95% CI 3.753-7.016), Black race (HR 1.445; 95% CI 1.016-2.055), and Charlson-Deyo comorbidity score > 0 (HR 1.708; 95% CI 1.403-2.079) were unfavorable prognostic factors. After PSM, 5-year OS was 91.7% for those who received radiotherapy and 84.5% for those who did not; 10-year OS was 76.1% and 64.1%, respectively (p < 0.001). CONCLUSION: This is the largest study to date on TC and the prognostic impact of adjuvant radiotherapy. Postoperative radiotherapy is a favorable prognostic factor for OS in patients with pN0M0 TC, suggesting adjuvant radiotherapy should remain standard of care in these patients.

Optimal Timing of Radiotherapy Following Gross Total or Subtotal Resection of Glioblastoma: A Real-World Assessment using the National Cancer Database.

Treatment for glioblastoma (GBM) includes surgical resection and adjuvant radiotherapy (RT) and chemotherapy. The optimal time interval between surgery and RT remains unclear. The National Cancer Database (NCDB) was queried for patients with GBM. Overall survival (OS) was estimated using Kaplan-Meier and log-rank tests. Univariate (UVA) and multivariable Cox regression (MVA) modeling was used to determine predictors of OS. A total of 45,942 patients were included. On MVA: younger age, female gender, black ethnicity, higher KPS, obtaining a gross total resection (GTR), MGMT promoter-methylated gene status, unifocal disease, higher RT dose, and RT delay of 4-8 weeks had improved OS. Patients who underwent a subtotal resection (STR) had worsened survival with RT delay ≤4 weeks and patients with GTR had worsened survival when RT was delayed >8 weeks. This analysis suggests that an interval of 4-8 weeks between resection and RT results in better survival. Delays >8 weeks in patients with a GTR and delays <4 weeks in patients with a STR/biopsy resulted in worse survival. This impact of time delay from surgery to RT, in conjunction with extent of resection, should be considered in the clinical management of patients and future designs of clinical trials.

The Use of "QUAD Shot" in Anal Canal Squamous Cell Carcinoma: A Case Study With Review of the Literature.

CONTEXT: Patients with locoregional anal carcinoma who do not qualify for standard definitive chemoradiation are candidates for a short course of palliative hypofractionated radiotherapy such as QUAD Shot. METHODS: A 57-year-old man with massive locoregional squamous cell carcinoma of the anal canal was treated with QUAD Shot (14.8 Gy in four fractions over two consecutive days) repeated every four weeks for a total of two courses. RESULTS: He reported symptomatic relief following each course of radiation. In regard to his first QUAD Shot, his pain was 10/10 in severity at the time of admission and 4/10 at the time of discharge. In regard to his second QUAD Shot, his pain was 8/10 at the time of admission and 0/10 at the time of discharge. He did not experience any treatment-related toxicity. He passed away 15 weeks after the first course. CONCLUSION: QUAD Shot is both efficacious and safe for palliation in patients with anal carcinoma.