Hypofractionated, 3-week, preoperative radiotherapy for patients with soft tissue sarcomas (HYPORT-STS): a single-centre, open-label, single-arm, phase 2 trial.

BACKGROUND: The standard preoperative radiotherapy regimen of 50 Gy delivered in 25 fractions for 5 weeks for soft tissue sarcomas results in excellent local control, with major wound complications occurring in approximately 35% of patients. We aimed to investigate the safety of a moderately hypofractionated, shorter regimen of radiotherapy, which could be more convenient for patients. METHODS: This single-centre, open-label, single-arm, phase 2 trial (HYPORT-STS) was done at a single tertiary cancer care centre (MD Anderson Cancer Center, Houston, TX, USA). We administered preoperative radiotherapy to a dose of 42·75 Gy in 15 fractions of 2·85 Gy/day for 3 weeks (five fractions per week) to adults (aged ≥18 years) with non-metastatic soft tissue sarcomas of the extremities or superficial trunk and an Eastern Cooperative Oncology Group performance status of 0-3. The primary endpoint was a major wound complication occurring within 120 days of surgery. Major wound complications were defined as those requiring a secondary operation, or operations, under general or regional anaesthesia for wound treatment; readmission to the hospital for wound care; invasive procedures for wound care; deep wound packing to an area of wound measuring at least 2 cm in length; prolonged dressing changes; repeat surgery for revision of a split thickness skin graft; or wet dressings for longer than 4 weeks. We analysed our primary outcome and safety in all patients who enrolled. We monitored safety using a Bayesian, one-arm, time-to-event stopping rule simulator comparing the rate of major wound complications at 120 days post-surgery among study participants with the historical rate of 35%. This trial is registered with ClinicalTrials.gov, NCT03819985, recruitment is complete, and follow-up continues. FINDINGS: Between Dec 18, 2018, and Jan 6, 2021, we assessed 157 patients for eligibility, of whom 120 were enrolled and received hypofractionated preoperative radiotherapy. At no time did the stopping rule computation indicate that the trial should be stopped early for lack of safety. Median postoperative follow-up was 24 months (IQR 17-30). Of 120 patients, 37 (31%, 95% CI 24-40) developed a major wound complication at a median time of 37 days (IQR 25-59) after surgery. No patient had acute radiation toxicity (during radiotherapy or within 4 weeks of the radiotherapy end date) of grade 3 or worse (Common Terminology Criteria for Adverse Events [CTCAE] version 4.0) or an on-treatment serious adverse event. Four (3%) of 115 patients had late radiation toxicity (≥6 months post-surgery) of at least grade 3 (CTCAE or Radiation Therapy Oncology Group/European Organisation for Research and Treatment of Cancer Late Radiation Morbidity Scoring Scheme): femur fractures (n=2), lymphoedema (n=1), and skin ulceration (n=1). There were no treatment-related deaths. INTERPRETATION: Moderately hypofractionated preoperative radiotherapy delivered to patients with soft tissue sarcomas was safe and could therefore be a more convenient alternative to conventionally fractionated radiotherapy. Patients can be counselled about these results and potentially offered this regimen, particularly if it facilitates care at a sarcoma specialty centre. Results on long-term oncological, late toxicity, and functional outcomes are awaited. FUNDING: The National Cancer Institute.

Gynecologic tract melanoma in the contemporary therapeutic era: High rates of local and distant disease progression.

BACKGROUND: Gynecologic tract melanoma (GTM) is a rare malignancy with historically poor outcomes. The current study examines patterns of care and oncologic outcomes in a large single-institution cohort from the contemporary therapeutic era. METHODS: Patterns of care and predictors of outcomes were evaluated for all GTM patients without metastatic disease at diagnosis who were treated at our institution between 2009 and 2020 with >6 months of follow-up. RESULTS: Of the 124 patients included, anatomic subsites were vulvar (n = 82, 66%), vaginal (n = 34, 27%), or cervical (n = 8, 6%). Primary tumor was resected for 85% (n = 106) with surgical nodal evaluation for 60% (n = 75). Systemic therapy, most commonly immune checkpoint inhibitors (ICI, 58% systemic therapy), was used to treat all except one unresectable patient (17/18) and 33% (35/106) of resectable patients. Seven patients received neoadjuvant ICI. Fourteen patients received adjuvant radiation therapy to the pelvis (RT, 13% of those undergoing resection). With a median follow-up of 45 months, 100 patients (81%) recurred. Four-year actuarial outcomes were: 46% local control, 53% nodal control, 36% distant metastasis-free survival, 17% disease-free survival, 49% melanoma-specific survival and 48% overall survival. Mitotic rate > 10/mm2, nodal involvement and non-vulvar anatomic subsite were associated with poor outcomes. Patients treated after 2016 did not have significantly better outcomes than those treated earlier. CONCLUSIONS: Patients with GTM continue to have poor outcomes in the contemporary therapeutic era with particularly notable poor local disease control relative to other mucosal melanoma subtypes. More effective oncologic therapy is needed.

Evaluating the Soft Tissue Sarcoma Paradigm for the Local Management of Extraskeletal Ewing Sarcoma.

OBJECTIVES: We reviewed our experience treating patients with localized extraskeletal Ewing sarcoma (EES) to determine optimal local management strategies for this rare disease. METHODS: Sixty patients with localized EES treated at our institution between 1994 and 2018 were reviewed. The Kaplan-Meier method was used to estimates disease outcomes. RESULTS: The median follow-up time was 74 months (interquartile range [IQR], 17-121). Half the patients (n = 30) received combined-modality local therapy (CMT) with both surgery and radiation therapy (RT), whereas the other half received single-modality local therapy (SMT) with either surgery or RT. All patients received chemotherapy. The 5-year overall survival was 76%. Twenty-two patients (37%) developed recurrence at a median time of 15 months (IQR, 5-56 months) resulting in 3-year progression-free survival (PFS) of 65%. On univariate analysis, the use of both neoadjuvant and adjuvant chemotherapy was associated with improved 5-year PFS (71% vs. 50%, p = .04) compared with those who received one or the other. Furthermore, 11 patients (18%) developed local recurrences at a median time of 14 months (IQR, 2-19 months), resulting in a 5-year local control (LC) rate of 77%. Use of CMT was not associated with improved LC (83% vs. 72% SMT, p = .41). Also, use of CMT was the only factor associated with poorer disease-specific survival (vs. SMT; hazard ratio, 3.4; p = .047; 95% confidence interval, 1.01-11.4). CONCLUSION: For patients with EES, CMT was not associated with a decreased rate of local relapse. These data suggest that SMT alone may be sufficient for LC in select patients. A multi-institutional collaborative effort should be considered to validate these findings. IMPLICATIONS FOR PRACTICE: Extraskeletal Ewing sarcoma is a rare chemosensitive sarcoma whose clinical course more closely follows Ewing sarcoma of bone rather than that of other soft tissue sarcomas. Based on this study, combined-modality local therapy did not confer a local control advantage compared with single-modality local therapy. Therefore, single-modality local therapy is likely adequate in select patients with favorable disease features, which has the advantage of ensuring prompt administration of systemic therapy. A multi-institutional collaborative effort is warranted to determine which patients may benefit from de-escalated local therapy.

Nodal Recurrence is a Primary Driver of Early Relapse for Patients with Sentinel Lymph Node-Positive Melanoma in the Modern Therapeutic Era.

BACKGROUND: Management of patients with sentinel lymph node (SLN)-positive melanoma has changed dramatically over the last few years such that completion lymph node dissection (CLND) has become uncommon, and many patients receive adjuvant immunotherapy or targeted therapy. This study seeks to characterize patterns and predictors of early recurrence in this setting. PATIENTS AND METHODS: All patients with primary cutaneous melanoma undergoing sentinel lymph node biopsy (SLNB) between 3/2016 and 12/2019 were identified. The subset with a positive SLN who did not undergo CLND were examined for further analysis of outcomes and predictors of recurrence. RESULTS: Overall, 215 patients with SLN-positive melanoma who did not have CLND were identified. Adjuvant systemic therapy was administered to 102 (47%), with 93% of this subset receiving immunotherapy (n = 95). Median follow-up from SLNB was 20 months (IQR 12-28.5 months), and 57 patients (27%) recurred during this time. The SLN basin was the most common site of recurrence (n = 38, 67% of recurrence), with isolated nodal recurrence being the most common first site of recurrent disease (n = 22, 39% of recurrence). On multivariable analysis, lymphovascular invasion (LVI) of the primary tumor, two or more involved nodes, and > 1 mm nodal deposit were independently associated with higher rates of nodal relapse. CONCLUSIONS: Nodal recurrence is a primary driver of early disease relapse for patients with SLN-positive melanoma who do not undergo CLND in the era of effective adjuvant systemic therapy. LVI, ≥ 2 nodes, or > 1 mm nodal disease identifies patients at particularly high risk of nodal relapse.

Chemoradiation-Related Lymphopenia and Its Association with Survival in Patients with Squamous Cell Carcinoma of the Anal Canal.

BACKGROUND: Although treatment-related lymphopenia (TRL) is common and associated with poorer survival in multiple solid malignancies, few data exist for anal cancer. We evaluated TRL and its association with survival in patients with anal cancer treated with chemoradiation (CRT). MATERIALS AND METHODS: A retrospective analysis of 140 patients with nonmetastatic anal squamous cell carcinoma (SCC) treated with definitive CRT was performed. Total lymphocyte counts (TLC) at baseline and monthly intervals up to 12 months after initiating CRT were analyzed. Multivariable Cox regression analysis was performed to evaluate the association between overall survival (OS) and TRL, dichotomized by grade (G)4 TRL (<0.2k/µL) 2 months after initiating CRT. Kaplan-Meier and log-rank tests were used to compare OS between patients with versus without G4 TRL. RESULTS: Median time of follow-up was 55 months. Prior to CRT, 95% of patients had a normal TLC (>1k/µL). Two months after initiating CRT, there was a median of 71% reduction in TLC from baseline and 84% of patients had TRL: 11% G1, 31% G2, 34% G3, and 8% G4. On multivariable Cox model, G4 TRL at two months was associated with a 3.7-fold increased risk of death. On log-rank test, the 5-year OS rate was 32% in the cohort with G4 TRL versus 86% in the cohort without G4 TRL. CONCLUSION: TRL is common and may be another prognostic marker of OS in anal cancer patients treated with CRT. The association between TRL and OS suggests an important role of the host immunity in anal cancer outcomes. IMPLICATIONS FOR PRACTICE: This is the first detailed report demonstrating that standard chemoradiation (CRT) commonly results in treatment-related lymphopenia (TRL), which may be associated with a poorer overall survival (OS) in patients with anal squamous cell carcinoma. The association between TRL and worse OS observed in this study supports the importance of host immunity in survival among patients with anal cancer. These findings encourage larger, prospective studies to further investigate TRL, its predictors, and its relationship with survival outcomes. Furthermore, the results of this study support ongoing efforts of clinical trials to investigate the potential role of immunotherapy in anal cancer.

The Evolving Role of Radiation Therapy in Patients with Metastatic Soft Tissue Sarcoma.

PURPOSE OF REVIEW: The management of metastatic disease is evolving. As systemic therapies continue to improve, there is increasing recognition that local therapy to distant sites of disease impacts outcomes among many histologies, including sarcoma. Various local therapy strategies exist, but radiation therapy (RT) is particularly critical as it provides a non-invasive, yet locally ablative strategy for metastatic management. RECENT FINDINGS: Various delivery techniques including stereotactic body radiation therapy (SBRT) or hypofractionated RT can escalate the biologic dose while avoiding normal tissues in order to reduce tumor burden, provide durable local control, palliate symptoms, potentially prevent further seeding of metastatic lesions, and potentially prolong survival. This review summarizes the current state of the literature on the important role of RT for the treatment of metastatic sarcoma organized by the site of metastatic disease. Particularly for patients presenting with oligometastatic or oligoprogressive disease, consolidative RT is an important local therapy strategy to be considered in a multidisciplinary setting.

High IDO1 Expression Is Associated with Poor Outcome in Patients with Anal Cancer Treated with Definitive Chemoradiotherapy.

BACKGROUND: This study characterizes the tumor-immune microenvironment in pretreatment, localized anal squamous cell carcinoma (ASCC), including two markers that have not previously been studied in ASCC: indoleamine 2,3 dioxygenase 1 (IDO1) and human leukocyte antigen (HLA) class I. MATERIALS AND METHODS: Retrospective review identified 63 patients with ASCC receiving definitive chemoradiation between 2005 and 2016 with pretreatment tissue available. Immunohistochemistry was used to quantify cluster of differentiation 8 (CD8), programmed cell death protein 1, programmed death-ligand 1, HLA class I, and IDO1. Cox proportional hazards models evaluated associations between outcomes and immune markers, controlling for clinical characteristics. RESULTS: With a median follow-up of 35 months, 3-year overall survival was 78%. The only marker found to have a robust association with outcome was tumor IDO1. In general, the percentage of tumor cells expressing IDO1 was low (median 1%, interquartile range 0%-20%); however, patients with >50% of tumor cells expressing IDO1 had significantly worse overall survival (hazard ratio [HR] 4.7, p = .007) as well as higher local recurrence (HR 8.6, p = .0005) and distant metastasis (HR 12.7, p = .0002). Tumors with >50% IDO1 were also more likely to have the lowest quartile of CD8 infiltrate (<40 per high-power field, p = .024). CONCLUSION: ASCC has a diverse immune milieu. Although patients generally do well with standard therapy, IDO1 may serve as a prognostic indicator of poor outcome and could help identify a patient population that might benefit from IDO-targeted therapies. IMPLICATIONS FOR PRACTICE: After definitive chemoradiation, patients with locally advanced anal cancer may experience significant treatment morbidity and high risk of recurrence. The goal of the current study is to identify novel prognostic factors in the tumor-immune microenvironment that predict for poor outcomes after definitive chemoradiation. This study characterizes the tumor-immune microenvironment in pre-treatment, localized anal squamous cell carcinoma (ASCC), including two markers which have not previously been studied in ASCC: indoleamine 2,3 dioxygenase 1 (IDO1) and HLA class I. With a median follow-up of 3 years, this study demonstrated that high IDO1 expression is correlated with significantly worse 3-year overall survival (88% vs. 25%). Whereas recent studies of IDO1 inhibitors have shown mixed results, this study suggests that patients with anal cancer with high IDO1 expression have dismal prognosis and may represent a patient population primed for response to targeted IDO1 inhibition.

Enrichment of HER2 Amplification in Brain Metastases from Primary Gastrointestinal Malignancies.

BACKGROUND: In nongastric gastrointestinal (GI) cancers, HER2-positive (HER2+) disease is not common. In breast cancer, HER2 status is associated with increased risk of brain metastases and response to HER2-targeted therapy. The purpose of this project was to compare HER2 status in GI cancer brain metastases versus matched prior sites of disease in order to determine if HER2+ disease is more common intracranially. MATERIALS AND METHODS: We identified 28 patients with GI cancer who had craniotomy for brain metastases between 1999 and 2017 with intracranial metastatic tissue available at Massachusetts General Hospital. Twenty-four patients also had tissue from a prior site of disease. Fluorescence in situ hybridization (FISH) and immunohistochemistry (IHC) for HER2 were performed on all samples. A tumor was defined as HER2+ if it had 3+ staining by IHC or amplification by FISH. RESULTS: A prior site of disease (including intracranial metastases) was HER2+ for 13% of evaluable patients: 3 of 11 patients with colorectal cancer and no patients with esophageal or pancreatic cancer. The most recent brain metastases were HER2+ for 32% of patients: 2 of 3 esophageal squamous cell carcinomas, 3 of 10 esophageal adenocarcinomas (ACs), 3 of 14 colorectal ACs, and 1 of 1 pancreatic AC. Only 37.5% of patients with HER2+ brain metastasis had concordant HER2+ prior tissue (κ = 0.38, p = .017). CONCLUSION: In this cohort of patients with GI cancer with brain metastases, HER2+ status was more common intracranially compared with prior sites of disease. These findings suggest that testing HER2 in patients with GI cancer with brain metastases may lead to additional therapeutic options, regardless of HER2 status in previously examined tissue. IMPLICATIONS FOR PRACTICE: HER2 amplification is a well-known driver of oncogenesis in breast cancer, with associated increased risk of brain metastases and response to HER2-directed therapy. In nongastric gastrointestinal (GI) cancers, HER2 amplification is not common and consequently is infrequently tested. The current study shows that brain metastases in patients with GI primary malignancies have a relatively high likelihood of being HER2 positive despite HER2 amplification or overexpression being less commonly found in matched tissue from prior sites of disease. This suggests that regardless of prior molecular testing, patients with GI cancer with brain metastases who have tissue available are likely to benefit from HER2 assessment to identify potential novel therapeutic options.

Denaturation-Enhanced Droplet Digital PCR for Liquid Biopsies.

BACKGROUND: Although interest in droplet-digital PCR technology (ddPCR) for cell-free circulating DNA (cfDNA) analysis is burgeoning, the technology is compromised by subsampling errors and the few clinical targets that can be analyzed from limited input DNA. The paucity of starting material acts as a "glass ceiling" in liquid biopsies because, irrespective how analytically sensitive ddPCR techniques are, detection limits cannot be improved past DNA input limitations. METHODS: We applied denaturation-enhanced ddPCR (dddPCR) using fragmented genomic DNA (gDNA) with defined mutations. We then tested dddPCR on cfDNA from volunteers and patients with cancer for commonly-used mutations. gDNA and cfDNA were tested with and without end repair before denaturation and digital PCR. RESULTS: By applying complete denaturation of double-stranded DNA before ddPCR droplet formation the number of positive droplets increased. dddPCR using gDNA resulted in a 1.9-2.0-fold increase in data-positive droplets, whereas dddPCR applied on highly-fragmented cfDNA resulted in a 1.6-1.7-fold increase. End repair of cfDNA before denaturation enabled cfDNA to display a 1.9-2.0-fold increase in data-positive signals, similar to gDNA. Doubling of data-positive droplets doubled the number of potential ddPCR assays that could be conducted from a given DNA input and improved ddPCR precision for cfDNA mutation detection. CONCLUSIONS: dddPCR is a simple and useful modification in ddPCR that enables extraction of more information from low-input clinical samples with minor change in protocols. It should be applicable to all ddPCR platforms for mutation detection and, potentially, for gene copy-number analysis in cancer and prenatal screening.

An ultraviolet-radiation-independent pathway to melanoma carcinogenesis in the red hair/fair skin background.

People with pale skin, red hair, freckles and an inability to tan--the 'red hair/fair skin' phenotype--are at highest risk of developing melanoma, compared to all other pigmentation types. Genetically, this phenotype is frequently the product of inactivating polymorphisms in the melanocortin 1 receptor (MC1R) gene. MC1R encodes a cyclic AMP-stimulating G-protein-coupled receptor that controls pigment production. Minimal receptor activity, as in red hair/fair skin polymorphisms, produces the red/yellow pheomelanin pigment, whereas increasing MC1R activity stimulates the production of black/brown eumelanin. Pheomelanin has weak shielding capacity against ultraviolet radiation relative to eumelanin, and has been shown to amplify ultraviolet-A-induced reactive oxygen species. Several observations, however, complicate the assumption that melanoma risk is completely ultraviolet-radiation-dependent. For example, unlike non-melanoma skin cancers, melanoma is not restricted to sun-exposed skin and ultraviolet radiation signature mutations are infrequently oncogenic drivers. Although linkage of melanoma risk to ultraviolet radiation exposure is beyond doubt, ultraviolet-radiation-independent events are likely to have a significant role. Here we introduce a conditional, melanocyte-targeted allele of the most common melanoma oncoprotein, BRAF(V600E), into mice carrying an inactivating mutation in the Mc1r gene (these mice have a phenotype analogous to red hair/fair skin humans). We observed a high incidence of invasive melanomas without providing additional gene aberrations or ultraviolet radiation exposure. To investigate the mechanism of ultraviolet-radiation-independent carcinogenesis, we introduced an albino allele, which ablates all pigment production on the Mc1r(e/e) background. Selective absence of pheomelanin synthesis was protective against melanoma development. In addition, normal Mc1r(e/e) mouse skin was found to have significantly greater oxidative DNA and lipid damage than albino-Mc1r(e/e) mouse skin. These data suggest that the pheomelanin pigment pathway produces ultraviolet-radiation-independent carcinogenic contributions to melanomagenesis by a mechanism of oxidative damage. Although protection from ultraviolet radiation remains important, additional strategies may be required for optimal melanoma prevention.

Pros and cons of vaginal brachytherapy after external beam radiation therapy in endometrial cancer.

A large number of studies have looked at the role of radiation therapy in the treatment of endometrial cancer. One particular radiation strategy in common practice is the use of adjuvant external beam (EB) radiotherapy followed by vaginal brachytherapy (VB). While the addition of VB to EB provides a theoretical benefit of a localized boost with higher focused dose to an area of potentially high recurrence risk, a randomized clinical trial to compare outcomes and toxicities of EB+VB vs. EB alone is lacking. The goal of this review is to present the current data for and against the use of this combined radiation modality and to provide some preliminary evidence regarding which patient populations may be most likely to benefit.

Quantitative assessment of Tet-induced oxidation products of 5-methylcytosine in cellular and tissue DNA.

Recent studies showed that Ten-eleven translocation (Tet) family dioxygenases can oxidize 5-methyl-2'-deoxycytidine (5-mdC) in DNA to yield the 5-hydroxymethyl, 5-formyl and 5-carboxyl derivatives of 2'-deoxycytidine (5-HmdC, 5-FodC and 5-CadC). 5-HmdC in DNA may be enzymatically deaminated to yield 5-hydroxymethyl-2'-deoxyuridine (5-HmdU). After their formation at CpG dinucleotide sites, these oxidized pyrimidine nucleosides, particularly 5-FodC, 5-CadC, and 5-HmdU, may be cleaved from DNA by thymine DNA glycosylase, and subsequent action of base-excision repair machinery restores unmethylated cytosine. These processes are proposed to be important in active DNA cytosine demethylation in mammals. Here we used a reversed-phase HPLC coupled with tandem mass spectrometry (LC-MS/MS/MS) method, along with the use of stable isotope-labeled standards, for accurate measurements of 5-HmdC, 5-FodC, 5-CadC and 5-HmdU in genomic DNA of cultured human cells and multiple mammalian tissues. We found that overexpression of the catalytic domain of human Tet1 led to marked increases in the levels of 5-HmdC, 5-FodC and 5-CadC, but only a modest increase in 5-HmdU, in genomic DNA of HEK293T cells. Moreover, 5-HmdC is present at a level that is approximately 2-3 and 3-4 orders of magnitude greater than 5-FodC and 5-CadC, respectively, and 35-400 times greater than 5-HmdU in the mouse brain and skin, and human brain. The robust analytical method built a solid foundation for dissecting the molecular mechanisms of active cytosine demethylation, for measuring these 5-mdC derivatives and assessing their involvement in epigenetic regulation in other organisms and for examining whether these 5-mdC derivatives can be used as biomarkers for human diseases.

Outcomes for Patients With Head and Neck Sarcoma Treated Curatively With Radiation Therapy and Surgery.

PURPOSE: Soft tissue sarcomas (STSs) of the head and neck (H&N) are rare malignancies that are challenging to manage. We sought to describe the outcomes of patients treated with curative intent using combined surgery and radiation therapy (RT) for H&N STS. METHODS AND MATERIALS: We performed a single-institution retrospective review of patients with nonmetastatic STS of the H&N who were treated from 1968 to 2020. The Kaplan-Meier method was used to estimate disease-specific survival (DSS) and local control (LC). Multivariable analyses (MVAs) were conducted using Cox proportional hazards model. RESULTS: One hundred ninety-two patients had a median follow-up of 82 months. Tumors arose in the neck (n = 50, 26%), paranasal sinuses (n = 36, 19%), or face (n = 23, 12%). Most patients were treated with postoperative RT (n = 134, 70%). Postoperative RT doses were higher (median, 60 Gy; preoperative dose, 50 Gy; P < .001). Treatment sequence was not associated with LC (preoperative RT, 78% [63%-88%]; postoperative RT, 75% [66%-82%]; P = .48). On MVA, positive/uncertain margin was the only variable associated with LC (hazard ratio [HR], 2.54; 95% CI, 1.34-4.82; P = .004). LC was significant on MVA (HR, 4.48; 95% CI, 2.62-7.67; P < .001) for DSS. Patients who received postoperative RT were less likely to experience a major wound complication (7.5% vs 22.4%; HR, 0.28; 95% CI, 0.11-0.68; P = .005). There was no difference in the rate of late toxicities between patients who received preoperative or postoperative RT. CONCLUSIONS: H&N STS continues to have relatively poorer LC than STS of the trunk or extremities. We found LC to be associated with DSS. Timing of RT did not impact oncologic or long-term toxicity outcomes; however, preoperative RT did increase the chance of developing a major wound complication.

Redefining FLASH RT: the impact of mean dose rate and dose per pulse in the gastrointestinal tract.

Background: The understanding of how varying radiation beam parameter settings affect the induction and magnitude of the FLASH effect remains limited. Purpose: We sought to evaluate how the magnitude of radiation-induced gastrointestinal (GI) toxicity (RIGIT) depends on the interplay between mean dose rate (MDR) and dose per pulse (DPP). Methods: C57BL/6J mice were subjected to total abdominal irradiation (11-14 Gy single fraction) under conventional irradiation (low DPP and low MDR, CONV) and various combinations of DPP and MDR up to ultra-high-dose-rate (UHDR) beam conditions. The effects of DPP were evaluated for DPPs of 1-6 Gy while the total dose and MDR were kept constant; the effects of MDR were evaluated for the range 0.3- 1440 Gy/s while the total dose and DPP were kept constant. RIGIT was quantified in non-tumor-bearing mice through the regenerating crypt assay and survival assessment. Tumor response was evaluated through tumor growth delay. Results: Within each tested total dose using a constant MDR (>100 Gy/s), increasing DPP led to better sparing of regenerating crypts, with a more prominent effect seen at 12 and 14 Gy TAI. However, at fixed DPPs >4 Gy, similar sparing of crypts was demonstrated irrespective of MDR (from 0.3 to 1440 Gy/s). At a fixed high DPP of 4.7 Gy, survival was equivalently improved relative to CONV for all MDRs from 0.3 Gy/s to 104 Gy/s, but at a lower DPP of 0.93 Gy, increasing MDR produced a greater survival effect. We also confirmed that high DPP, regardless of MDR, produced the same magnitude of tumor growth delay relative to CONV using a clinically relevant melanoma mouse model. Conclusions: This study demonstrates the strong influence that the beam parameter settings have on the magnitude of the FLASH effect. Both high DPP and UHDR appeared independently sufficient to produce FLASH sparing of GI toxicity, while isoeffective tumor response was maintained across all conditions.

SABR for Sarcoma Lung Metastases: Indications for Treatment and Guidance for Patient Selection.

PURPOSE: The lungs are the most common site of metastasis for patients with soft tissue sarcoma. SABR is commonly employed to treat lung metastases among select patients with sarcoma with limited disease burden. We sought to evaluate outcomes and patterns of failure among patients with sarcoma treated with SABR for their lung metastases. METHODS AND MATERIALS: We performed a retrospective review of patients treated at a tertiary cancer center between 2006 and 2020. Patient disease status at the time of SABR was categorized as either oligorecurrent or oligoprogressive. The Kaplan-Meier method was used to estimate disease outcomes. Uni- and multivariable analyses were conducted using the Cox proportional hazards model. RESULTS: We identified 70 patients with soft tissue sarcoma treated with SABR to 98 metastatic lung lesions. Local recurrence-free survival after SABR treatment was 83% at 2 years. On univariable analysis, receipt of comprehensive SABR to all sites of pulmonary metastatic disease at the time of treatment was associated with improved progression-free survival (PFS; hazard ratio [HR], 0.51 [0.29-0.88]; P = .02). On multivariable analysis, only having systemic disease controlled at the time of SABR predicted improved PFS (median PFS, 14 vs 4 months; HR, 0.37 [0.20-0.69]; P = .002) and overall survival (median overall survival, 51 vs 14 months; HR, 0.17 [0.08-0.35]; P < .0001). CONCLUSIONS: SABR provides durable long-term local control for sarcoma lung metastases. The most important predictor for improved outcomes was systemic disease control. Careful consideration of these factors should help guide decisions in a multidisciplinary setting to appropriately select the optimal candidates for SABR.

High-Grade Pleomorphic Sarcomas Treated with Immune Checkpoint Blockade: The MD Anderson Cancer Center Experience.

BACKGROUND: Undifferentiated pleomorphic sarcomas (UPSs) are amongst the most common subtypes of soft-tissue sarcomas. Few real-world data on the use of immune checkpoint blockade (ICB) in UPS patients and other high-grade pleomorphic STS patients are available. PURPOSE: The purpose of our study is to describe the efficacy and toxicity of ICB in patients with advanced UPSs and other high-grade pleomorphic sarcomas treated at our institution. METHODS: This is a retrospective, observational study of all patients with metastatic high-grade pleomorphic sarcomas treated with FDA-approved ICB at MD Anderson Cancer Center between 1 January 2015 and 1 January 2023. Patients included in trials for which results are not yet published were excluded. RESULTS: Thirty-six patients with advanced/metastatic pleomorphic sarcomas were included. The median age was 52 years. A total of 26 patients (72%) had UPSs and 10 patients (28%) had other high-grade pleomorphic sarcomas. The median follow-up time was 8.8 months. The median PFS was 2.9 months. The 3-month PFS and 6-month PFS were 46% and 32%, respectively. The median OS was 12.9 months. The 12-month OS and 24-month OS were 53% and 29%, respectively. The best response, previous RT, and type of ICB treatment were significantly and independently associated with shorter PFS (p = 0.0012, p = 0.0019 and p = 0.036, respectively). No new safety signal was identified, and the toxicity was overall manageable with no toxic deaths and only four patients (11%) stopping treatment due to toxicity. CONCLUSIONS: Real-world retrospective data are consistent with the published literature, with a promising 6-month PFS of 32%. Partial or stable responders to ICB treatment have significantly improved PFS compared to progressors.

Radiation Therapy for Retroperitoneal Sarcomas: A Strass-Ful Situation.

Locoregional recurrence (LRR) is the predominant pattern of relapse and often the cause of death in patients with retroperitoneal sarcomas (RPS). As a result, reducing LRR is a critical objective for RPS patients. However, unlike soft tissue sarcomas (STS) of the superficial trunk and extremity where the benefits of radiation therapy (RT) are well-established, the role of RT in the retroperitoneum remains controversial. Historically, preoperative or postoperative RT, either alone or in combination with intraoperative radiation (IORT), was commonly justified for RPS based on extrapolation from the superficial trunk and extremity STS literature. However, long-awaited results were recently published from the European Organization for Research and Treatment of Cancer (EORTC) STRASS study of preoperative radiotherapy plus surgery versus surgery alone for patients with RPS; there was no statistical difference in the primary endpoint of abdominal recurrence-free survival. However, several subset analyses and study limitations complicate the interpretation of the results. This review explores and contextualizes the body of evidence regarding RT's role in managing RPS.

Outcomes after definitive treatment for cutaneous angiosarcomas of the face and scalp: Reevaluating the role of surgery and radiation therapy.

INTRODUCTION: We investigated outcomes and prognostic factors for patients treated for cutaneous angiosarcoma (CA). METHODS: We conducted a retrospective review of patients treated for CA of the face and scalp from 1962 to 2019. All received definitive treatment with surgery, radiation (RT), or a combination (S-XRT). The Kaplan-Meier method was used to estimate outcomes. Multivariable analyses were conducted using the Cox proportional hazards model. RESULTS: For the 143 patients evaluated median follow-up was 33 months. Five-year LC was 51% and worse in patients with tumors >5 cm, multifocal tumors, those treated pre-2000, and with single modality therapy (SMT). These remained associated with worse LC on multivariable analysis. The 5-year disease-specific survival (DSS) for the cohort was 56%. Tumor size >5 cm, non-scalp primary site, treatment pre-2000, and SMT were associated with worse DSS. CONCLUSION: Large or multifocal tumors are negative prognostic factors in patients with head and neck CA. S-XRT improved outcomes.

Association of Parental Status and Gender With Burden of Multidisciplinary Tumor Boards Among Oncology Physicians.

Importance: Tumor boards are integral to the care of patients with cancer. However, data investigating the burden of tumor boards on physicians are limited. Objective: To investigate what physician-related and tumor board-related factors are associated with higher tumor board burden among oncology physicians. Design, Setting, and Participants: Tumor board burden was assessed by a cross-sectional convenience survey posted on social media and by email to Cedars-Sinai Medical Center cancer physicians between March 3 and April 3, 2022. Tumor board start times were independently collected by email from 22 top cancer centers. Main Outcomes and Measures: Tumor board burden was measured on a 4-point scale (1, not at all burdensome; 2, slightly burdensome; 3, moderately burdensome; and 4, very burdensome). Univariable and multivariable probabilistic index (PI) models were performed. Results: Surveys were completed by 111 physicians (median age, 42 years [IQR, 36-50 years]; 58 women [52.3%]; 60 non-Hispanic White [54.1%]). On multivariable analysis, factors associated with higher probability of tumor board burden included radiology or pathology specialty (PI, 0.68; 95% CI, 0.54-0.79; P = .02), attending 3 or more hours per week of tumor boards (PI, 0.68; 95% CI, 0.58-0.76; P < .001), and having 2 or more children (PI, 0.65; 95% CI, 0.52-0.77; P = .03). Early or late tumor boards (before 8 am or at 5 pm or after) were considered very burdensome by 33 respondents (29.7%). Parents frequently reported a negative burden on childcare (43 of 77 [55.8%]) and family dynamics (49 of 77 [63.6%]). On multivariable analysis, a higher level of burden from early or late tumor boards was independently associated with identifying as a woman (PI, 0.69; 95% CI, 0.57-0.78; P = .003) and having children (PI, 0.75; 95% CI, 0.62-0.84; P < .001). Independent assessment of 358 tumor boards from 22 institutions revealed the most common start time was before 8 am (88 [24.6%]). Conclusions and Relevance: This survey study of tumor board burden suggests that identifying as a woman or parent was independently associated with a higher level of burden from early or late tumor boards. The burden of early or late tumor boards on childcare and family dynamics was commonly reported by parents. Having 2 or more children, attending 3 or more hours per week of tumor boards, and radiology or pathology specialty were associated with a significantly higher tumor board burden overall. Future strategies should aim to decrease the disparate burden on parents and women.

Primary tumor site for localized Merkel cell carcinoma drives different management strategies without impacting oncologic outcomes.

BACKGROUND AND PURPOSE: Clinically localized Merkel cell carcinoma (MCC) has been associated with high rates of disease relapse. This study examines how primary tumor anatomic site drives patterns of care and outcomes in a large cohort treated in the contemporary era. MATERIALS AND METHODS: Patterns of care and associated outcomes were evaluated for clinically Stage I-II MCC patients treated at our institution with adjuvant radiation therapy (RT) to the primary site and/or regional nodal basin as a component of their curative intent therapy between 2014-2021. RESULTS: Of 80 patients who met inclusion criteria, the primary tumor anatomic site was head and neck (HN) for 42 (53%) and non-head and neck (NHN) for 38 (47%). Primary tumor risk factors were similar between cohorts. Fewer patients with HN tumors had wide local excision (WLE; HN-81% vs. NHN-100% p < 0.01). Of those undergoing WLE, patients with HN tumors received higher dose adjuvant RT (>50 Gy: HN-70% vs. NHN-8%; p < 0.01). Patients with HN tumors were less likely to undergo sentinel lymph node biopsy (HN-62%vs. NHN-100%; p < 0.01) and more likely to have elective nodal RT (HN-48% vs. NHN-0%). Despite varying management strategies, there was no significant difference in local recurrence-free survival (3-yr LRFS HN-94% vs. NHN-94%; p = 0.97), nodal recurrence-free survival (3-yr NRFS HN-89% vs. NHN-85%; p = 0.71) or overall recurrence-free survival (3-yr RFS 73% HN vs. 80% NHN; p = 0.44). CONCLUSIONS: Among patients with primary MCC who had RT as a component of their initial treatment strategy, anatomically-driven heterogeneous treatment approaches were associated with equally excellent locoregional disease control.