Assessing the effect of metastasis-directed therapy in oligometastatic disease using the restricted mean survival time.

BACKGROUND: Metastasis-directed therapy (MDT) with stereotactic body radiotherapy (SBRT) is emerging as an effective therapeutic option for oligometastatic disease (OMD). However, a lack of phase III data, consensus guidelines, and toxicity concerns limit its widespread use. Randomized controlled trials (RCTs) routinely report hazard ratios (HRs) and medians that lack clear clinical and robust interpretation. Restricted-mean survival time (RMST) is the duration of time a patient is expected to survive over the follow-up period, providing a robust and interpretable alternative. We analyzed the efficacy of SBRT using RMST. METHODS: All registered RCTs of ablative radiotherapy in OMD in ClinicalTrials.gov through 2022 were identified. Data were reconstructed from Kaplan-Meier curves, and the HRs and RMST differences were estimated for surrogate endpoints (SEs) and overall survival (OS). RESULTS: Six studies comprising 426 patients met the inclusion criteria. The RMST differences for SEs ranged from 4.6 months in a study by Iyengar et al. to 11.1 months in SABR-COMET. The RMST differences for OS in SABR-COMET, Gomez et al., and SINDAS studies were 12.6, 15 and 7.9 months, respectively. CONCLUSION: RMST demonstrates the efficacy of local treatment in OMD. Representing the expected survival time, this method effectively communicates outcomes to patients and clinicians.

SABR-Dual: a phase II/III trial of two-fraction versus five-fraction stereotactic radiotherapy for localized low- and favorable intermediate-risk prostate cancer.

BACKGROUND: Dose-escalated radiotherapy is known to improve progression free survival in patients with localized prostate cancer, and recent advances have led to the standardization of ultrahypofractionated stereotactic ablative radiotherapy (SABR) delivered in just 5-fractions. Based on the known effectiveness of the accepted though invasive 2-fraction treatment method of high-dose-rate brachytherapy and given the ubiquity of prostate cancer, a further reduction in the number of treatments of external-beam SABR is possible. This study aims to evaluate the safety, efficacy, and non-inferiority of generalizable 2-fraction SABR compared to the current 5-fraction regimen. METHODS: 502 patients will be enrolled on this phase II/III randomized control trial. Eligible patients will have previously untreated low- or favorable intermediate-risk adenocarcinoma of the prostate. Patients will be randomized between standard SABR of 40 Gy in 5 fractions given every-other-day and 27 Gy in 2 fractions at least two days apart but completing within seven days. MRI-based planning, radiopaque hydrogel spacer insertion, and fiducial marker placement are required, and SABR will be delivered on either a standard CT-guided linear accelerator or MR-LINAC. The primary endpoint will be freedom from disease progression, with additional secondary clinical, toxicity, and quality of life endpoints. DISCUSSION: This study will be the largest prospective randomized trial, adequately powered to demonstrate non-inferiority, comparing 2-fraction SABR to standard 5-fraction SABR for localized prostate cancer. As the protocol does not obligate use of an MRI-LINAC or other adaptive technologies, results will be broadly generalizable to the wider community. TRIAL REGISTRATION: This trial is registered on Clinicaltrials.gov: ClinicalTrials.gov Identifier: NCT06027892.

Alternative nivolumab duration and scheduling in advanced nonsmall cell lung cancer: A real-world evidence.

In advanced nonsmall cell lung cancer (aNSCLC), stopping nivolumab after 12 months negatively affects outcomes. We performed a world data-based analysis assessing the value of nivolumab continuation and optimal dosing beyond 24 months. Out of 697 consecutive patients with aNSCLC in whom nivolumab was initiated between 2015 and 2018, 45 patients receiving nivolumab for ≥24 months were selected. These were divided into Groups A: nivolumab administered at a dose 3 mg/kg q2 weeks/240 mg q2 weeks/480 mg q4 weeks, n = 25; B: nivolumab re-scheduled to a nonstandard dose 3 mg/kg q3 weeks-q8 weeks, n = 13; C: nivolumab stopped after 24 months, n = 7; (in Groups B and C-for reasons other than progressive disease or intolerable toxicity). Progression-free survival (PFS) (Revised Response Evaluation Criteria in Solid Tumors, version 1.1) and safety (Common Terminology Criteria for Adverse Events, version 4.03) were assessed. With median follow-up of 35.6 months (interquartile range 28.4-41.8), 4%, 31%, 29% and 30% of patients progressed in Groups A, B, C and B+C, respectively. PFS at 36 months since nivolumab initiation comprised 100%, 67%, 67% and 67%, in Groups A, B, C and B+C, respectively. PFS at 40 months since nivolumab initiation comprised 83%, 67%, 67% and 67%, in Groups A, B, C and B+C, respectively. Allocation to Group A vs Group B, C and B+C was associated with hazard ratio for PFS-0.20 (95% confidence interval [CI], 0.02-1.77, P-.15), 0.20 (95% CI, 0.02-2.25, P-.19) and 0.20 (95% CI, 0.02-1.66, P-.14), respectively. No differences in newly occurring or worsening adverse events between the groups were observed. A trend for worse PFS was observed with alternative nivolumab scheduling or quitting 24 months after initiation. Continuing nivolumab at a standard dose until disease progression or intolerable toxicity remains the standard treatment option.

The Impact of Exogenous Estrogen Exposure on the Characteristics and Outcome of Estrogen Receptor-Positive, Human Epidermal Growth Factor Receptor 2-Negative Early-Stage Breast Cancer.

INTRODUCTION: The impact of exogenous estrogen exposure on breast cancer characteristics and outcomes is not well described. We aimed to investigate the effect of prior treatment with oral contraceptives (OCT), hormone replacement therapy (HRT), and fertility treatments on early-stage, estrogen receptor (ER)-positive, human epidermal growth factor receptor 2 (HER2)-negative breast cancer. METHODS: This is a single-center retrospective cohort study comprising all women with ER-positive, HER2-negative, early breast cancer whose tumors were sent to Oncotype DX analysis between 2005 and 2012. Data on prior exposures to OCT, HRT, and fertility treatments were collected. The impact of these exposures on prespecified histopathological features was assessed including tumor size, nodal status, intensity of the hormonal receptors, grade, Oncotype recurrence score, Ki67, and lymphovascular and perineural invasion. The impact of these exposures on disease-free survival (DFS) and overall survival (OS) was also evaluated. RESULTS: A total of 620 women were included, of which 19% had prior exposure to OCT, 30% to HRT, and 11% to fertility treatments. OCT use was associated with smaller (≤1 cm) tumors (p = 0.023) and were less likely to have grade 3 disease (p = 0.049). No other associations were found between exogenous estrogen exposure and tumor characteristics. Median follow-up was 10.4 years. Ten-year DFS was 85.7%, and it was not influenced by exogenous exposure. Ten-year OS was 90.2%, and OCT was associated with improved OS in univariate analysis (HR = 0.31, 95% CI: 0.11-0.85), but this difference did not remain significant in multivariate analysis (p = 0.275). CONCLUSION: The impact of exogenous estrogen exposure on ER-positive, HER2-negative early breast cancer characteristics is limited. In the long term, none of the evaluated exposures had negative effect on DFS and OS.

Evolution in the risk of adverse events of adjuvant endocrine therapy in postmenopausal women with early-stage breast cancer.

BACKGROUND: Adjuvant endocrine therapy is a gold standard in early-stage, hormone receptor positive breast cancer. In postmenopausal women, aromatase inhibitors (AIs) are associated with improved outcome compared to tamoxifen monotherapy. Differences in the toxicity profiles of these drugs are described; however, little is known about whether the risk of adverse events changes over time. METHODS: Sequential reports of large, randomized, adjuvant endocrine therapy trials comparing AIs to tamoxifen were reviewed. Data on pre-specified adverse events were extracted including cardiovascular events, bone fractures, cerebrovascular disease, endometrial cancer, secondary malignancies excluding breast cancer, venous thrombosis and death without recurrence. Odds ratios (ORs) were calculated for each adverse event at each time over the course of follow-up. The change in the ORs for adverse events over time was evaluated using weighted linear regression. RESULTS: Analysis included 21 reports of 7 trials comprising 30,039 patients and reporting outcomes between 28 and 128 months of follow-up. Compared to tamoxifen, AIs use was associated with a significant reduction in the magnitude of increased odds of bone fracture over time (ß = - 0.63, p = 0.013). There was a non-significant decrease in the magnitude of reduced odds of secondary malignancies over time (ß = 0.448, p = 0.094). The differences in other toxicity profiles between AIs and tamoxifen did not change significantly over time. CONCLUSIONS: The increased risk of bone fractures associated with adjuvant AIs falls over time and after discontinuation of treatment. Differences in other toxicities between AIs and tamoxifen do not change significantly over time including a persistently elevated risk of cardiovascular events.

Young-onset gastric cancer and Epstein-Barr Virus (EBV) - a major player in the pathogenesis?

OBJECTIVE: Gastric cancer (GC) is a leading cause of cancer death, occurs predominantly in older age, with increasing incidence in young patients. The Cancer Genome Atlas indicates four subtypes for GC among which Epstein-Barr virus (EBV) subtype is estimated at 8.7%. We aim to determine the prevalence of EBV subtype in young GC patients (≤45 years) compared with an average-onset cohort (≥55 years) and characterize the clinicopathologic pattern of young-onset GC. METHODS: Gastric cancer samples of patients of both cohorts were screened for EBV by qPCR. Additional staining was done for Human epidermal growth factor receptor 2 (HER2), microsatellite instability (MSI) status and Programmed death-ligand 1 (PD-L1). Demographics and clinical data were retrieved from the medical records. RESULTS: Thirty-nine young-onset and 35 average-onset GC patients were reviewed. There was no apparent difference in tumor location, family history, histology and HER2 status between the cohorts. More young-onset patients were diagnosed with metastatic disease (27% vs 9%, p = 0.0498). EBV was significantly more prevalent in the young-onset cohort (33% vs 11%, p = 0.025). 15/17 EBV positive patients were under the median age of diagnosis for GC in the US (68 years). MSI-H was found only in the average-onset cohort [0% vs 27%, p = 0.001). PD-L1 positivity was higher in the young-onset cohort (31% vs 3%, p = 0.002). CONCLUSION: Our study indicates that EBV subtype is more prevalent in young-onset GC and may play a key role in the pathogenesis. Higher rate of PD-L1 positivity in young-onset GC could change treatment strategies. We are currently evaluating these findings in a prospective trial.

A Cost-Effectiveness Analysis of Nivolumab and Ipilimumab Versus Sunitinib in First-Line Intermediate- to Poor-Risk Advanced Renal Cell Carcinoma.

BACKGROUND: The treatment paradigm of advanced renal cell carcinoma (RCC) has changed rapidly in recent years. In first-line treatment of intermediate- to poor-risk patients, the CheckMate 214 study demonstrated a significant survival advantage for nivolumab and ipilimumab versus sunitinib. The high cost of combined immune-modulating agents warrants an understanding of the combination's value by considering both efficacy and cost. The objective of this study was to estimate the cost-effectiveness of nivolumab and ipilimumab compared with sunitinib for first-line treatment of intermediate- to poor-risk advanced RCC from the U.S. payer perspective. MATERIALS AND METHODS: A Markov model was developed to compare the costs and effectiveness of nivolumab and ipilimumab with those of sunitinib in the first-line treatment of intermediate- to poor-risk advanced RCC. Health outcomes were measured in life-years and quality-adjusted life-years (QALYs). Drug costs were based on Medicare reimbursement rates in 2017. We extrapolated survival beyond the trial closure using Weibull distribution. Model robustness was addressed in univariable and probabilistic sensitivity analyses. RESULTS: The total mean cost per-patient of nivolumab and ipilimumab versus sunitinib was $292,308 and $169,287, respectfully. Nivolumab and ipilimumab generated a gain of 0.978 QALYs over sunitinib. The incremental cost-effectiveness ratio (ICER) for nivolumab and ipilimumab was $125,739/QALY versus sunitinib. CONCLUSION: Our analysis established that the base case ICER in the model for nivolumab and ipilimumab versus sunitinib is below what some would consider the upper limit of the theoretical willingness-to-pay threshold in the U.S. ($150,000/QALY) and is thus estimated to be cost-effective. IMPLICATIONS FOR PRACTICE: This article assessed the cost-effectiveness of nivolumab and ipilimumab versus sunitinib for treatment of patients with intermediate- to poor-risk metastatic kidney cancer, from the U.S. payer perspective. It would cost $125,739 to gain 1 quality-adjusted life-year with nivolumab and ipilimumab versus sunitinib in these patients.

Outcome of radiotherapy for the treatment of laryngeal squamous cell carcinoma in the very elderly population.

BACKGROUND: Treatment selection for squamous cell carcinoma patients aged over 84 years is controversial. This retrospective chart review examined and compared characteristics of laryngeal squamous cell carcinoma in very elderly (over 84 years) and younger patients (approximately 65 years). The secondary objective was to further evaluate the outcome of radiotherapy as a treatment modality in this patient population. METHODS: Of all 23 very elderly patients with laryngeal squamous cell carcinoma treated with radiotherapy, with or without surgery, in the Davidoff Cancer Center, from 1992 to 2012, 19 had sufficient data for analysis, and comprised the study group. RESULTS: Median age at diagnosis was 86 years. Disease stage at diagnosis was I, II, III and IVA in 53 per cent, 21 per cent, 21 per cent and 5 per cent, respectively. Median radiotherapy dose was 60 Gy given in 25 fractions. Three patients had recurrence. No patient discontinued treatment because of toxicity. Median overall survival was 3.6 years (range, 0-10 years). CONCLUSION: Very elderly laryngeal squamous cell carcinoma patients may derive a similar survival advantage as younger counterparts. Modern radiotherapy is effective and safe for treating laryngeal squamous cell carcinoma in this study population. Further, large-scale studies are needed.

Effect of Radiological Tumor Thickness on Prognosis of Early Glottic-Squamous Cell Carcinoma Treated With Radiation.

OBJECTIVES: Tumor depth of invasion is a known prognostic factor in several head and neck cancers, but data on early laryngeal squamous cell carcinoma (SCC) are sparse. In this study, we aim to determine whether radiological tumor thickness serves as a prognostic factor in early SCC of the glottis treated with radiation. METHODS: One hundred thirty-two adult patients (age >18 years) underwent pretreatment computed tomography (CT) and were treated with radiation for pathologically proven early stage (T1 or T2) glottic SCC. Thirty-eight were excluded because the tumor could not be correctly identified on the CT scan, and an additional three patients because of insufficient data. RESULTS: The final cohort consisted of 91 patients, 84 (90.3%) men and 7 (9.7%) women aged 39.86-86.53 (mean 65.55 ± 12.76) years. Mean tumor thickness was 0.59 ± 0.19 cm in patients with T1 tumors and 0.79 ± 0.21 cm in patients with T2 tumors. The optimal cutoff value for 5-year disease-free survival (DFS), using the Youden index (sensitivity: 81.2%, specificity 65.3%), was 0.7 cm. A significant advantage in 5-year overall survival (OAS) and 5-year DFS for tumor thickness of <0.7 cm (P = 0.01 and P < 0.01, respectively) was found, these findings were consistent also when each stage was examined separately (T1 vs T2). CONCLUSION: Radiological tumor thickness appears to significantly predict OAS and DFS in early glottic SCC patients. IMPLICATION FOR PRACTICE: Tumor thickness may be considered as an auxiliary aid in deciding follow-up time and frequency, proper treatment, and determining prognosis.

The role of a radiopaque peri-rectal hydrogel spacer in aiding accurate daily image-guidance for prostate stereotactic radiotherapy.

Introduction: Precise patient positioning with image guidance (IGRT) is essential for safe prostate radiotherapy. We present the first report of utilizing a CT-visible hydrogel spacer, used to decrease rectal radiation dose, as a surrogate fiducial marker to aid in daily IGRT with cone-beam CT (CBCT) in stereotactic radiotherapy (SABR) for prostate cancer. Materials and methods: Prior to CT simulation, patients underwent placement of three intraprostatic gold fiducial markers and radiopaque hydrogel spacer per standard practice. At treatment, after initial setup, a CBCT was acquired and fused to the planning CT based on 3-dimensional matching of the spacer. A second alignment was then performed based on the fiducial markers. The six directional shifts (three linear and three rotational) were recorded, and the differences compared. Results: 140 individual fractions across 41 consecutive patients were evaluated. Mean/median differences between hydrogel spacer-based and fiducial-based alignment in linear (vertical, longitudinal, lateral) and rotational (rotation, pitch, roll) shifts were 0.9/0.6mm, 0.8/0.5mm, and 0.6/0.4mm, and 0.38/0, 0.62/0, and 0.35/0 degrees, respectively. No difference was observed in 9.9%, 22.9%, and 22.14% of linear shifts, and 65.7%, 65%, and 66.4% rotational shifts, respectively. Significantly smaller differences were observed in the latter 70 fractions vs. the former, and results were consistent across evaluators. Conclusions: For precise daily IGRT with CBCT for prostate SABR, alignment using a radiopaque hydrogel spacer was highly comparable to intraprostatic fiducial markers. This represents the first report supporting an additional indication of IGRT for a CT-visible hydrogel spacer, to further enhance treatment accuracy and potentially obviate the need for the additional fiducial marker procedure.

Acute Toxicity and Early Prostate Specific Antigen Response After Two-Fraction Stereotactic Radiation Therapy for Localized Prostate Cancer Using Peri-Rectal Spacing - Initial Report of the SABR-Dual Trial.

PURPOSE: SABR-Dual is a phase-III trial with an initial phase-I safety cohort, of 2-fraction stereotactic radiotherapy (SABR) with optional magnetic resonance imaging (MRI)-based focal boost, using peri-rectal spacing, for localized prostate cancer. This represents the initial report from the phase-I non-randomized cohort. METHODS AND MATERIALS: Subjects had favorable intermediate risk (FIR) or low risk prostate adenocarcinoma, and gland volume <80 cc. All underwent radiopaque hydrogel spacer and fiducial marker placement before simulation (computed tomography and 3-tesla T2 MRI). The clinical target volume included the entire prostate, and in FIR patients, 1-2 cm of seminal vesicle. A 2-mm expansion was applied for planning target volume (PTV), and a dose of 27 Gy was prescribed to the PTV-prostate, 23 Gy to the PTV-seminal vesicle, with an optional 30 Gy simultaneous boost to an MRI-defined dominant lesion. Primary endpoint was 3-month patient-reported changes in quality of life based on the Expanded Prostate Cancer Index Composite-26, International Prostate Symptom Score, and Sexual Health Inventory for Men questionnaires. Secondary endpoints were 6-month quality of life, acute toxicity (using Common Terminology Criteria for Adverse Events version 5.0) and early Prostate specific antigen (PSA) response. RESULTS: Among the 20 patients in the phase-I cohort, 95% had FIR disease, and 50% received a simultaneous boost. At median follow-up of 8 months, a 3-month minimally clinically important change occurred in 1/20 (5%), 6/20 (30%), 2/20 (10%), 4/20 (20%), and 5/20 (25%) in urinary incontinence, urinary obstructive, bowel, sexual, and hormonal domains. There was a mean increase of 1 ± 5.4 in International Prostate Symptom Score and decrease of 1.8 ± 6.5 in Sexual Health Inventory for Men scores. Rates of grade 2 urinary and bowel toxicity were 10% and 0%, respectively, with no grade ≥3 toxicities. Mean PSA decrease at last follow-up was 70.4% ± 17.7%. CONCLUSION: This generalizable protocol of 2-fraction prostate SABR using peri-rectal spacing is a safe approach for ultra-hypofractionated dose-escalation, with minimal acute toxicity. Longer-term outcomes and direct comparison with standard 5-fraction SABR are being studied in the phase-III randomized portion of SABR-Dual.

40 Gray in 5 Fractions for Salvage Reirradiation of Spine Lesions Previously Treated With Stereotactic Body Radiotherapy.

BACKGROUND AND PURPOSE: A retrospective single-center analysis of the safety and efficacy of reirradiation to 40 Gy in 5 fractions (reSBRT) in patients previously treated with stereotactic body radiotherapy to the spine was performed. METHODS: We identified 102 consecutive patients treated with reSBRT for 105 lesions between 3/2013 and 8/2021. Sixty-three patients (61.8%) were treated to the same vertebral level, and 39 (38.2%) to overlapping immediately adjacent levels. Local control was defined as the absence of progression within the treated target volume. The probability of local progression was estimated using a cumulative incidence curve. Death without local progression was considered a competing risk. RESULTS: Most patients had extensive metastatic disease (54.9%) and were treated to the thoracic spine (53.8%). The most common regimen in the first course of stereotactic body radiotherapy was 27 Gy in 3 fractions, and the median time to reSBRT was 16.4 months. At the time of simulation, 44% of lesions had advanced epidural disease. Accordingly, 80% had myelogram simulations. Both the vertebral body and posterior elements were treated in 86% of lesions. At a median follow-up time of 13.2 months, local failure occurred in 10 lesions (9.5%). The 6- and 12-month cumulative incidences of local failure were 4.8% and 6%, respectively. Seven patients developed radiation-related neuropathy, and 1 patient developed myelopathy. The vertebral compression fracture rate was 16.7%. CONCLUSION: In patients with extensive disease involvement, reSBRT of spine metastases with 40 Gy in 5 fractions seems to be safe and effective. Prospective trials are needed to determine the optimal dose and fractionation in this clinical scenario.

Same-day versus delayed simulation imaging after placement of a perirectal hydrogel spacer for prostate radiotherapy.

Introduction: Placement of a perirectal hydrogel spacer has been demonstrated to reduce the risk of rectal toxicity from prostate radiation. Practices vary regarding the timing of CT simulation after hydrogel placement, and the ideal schedule remains unknown. Methods: Thirty patients with localized prostate adenocarcinoma underwent transrectal ultrasound-guided placement of an iodinated SpaceOAR™ hydrogel prior to radiotherapy. Per evolving practice, 15 completed same-day simulation and 15 returned for simulation 1-2 weeks later. Hydrogel volume, perirectal distance, air-void volume, and rectal dosimetry per NRG GU005 were compared between CT simulation, 1st fraction Cone-Beam-CT (CBCT), and final CBCT. Results: CT simulation occurred 8.8 ± 2.4 days after placement in the delayed group, with no significant difference in the interval between simulation and 1st fraction between groups (p = 0.165). Greater observed de-creases in hydrogel volume (0.57 cc vs. 0.04 cc, p = 0.0002), and perirectal distance at both mid-gland (1.32 mm vs. 0.17 mm) and tallest point (2.40 mm vs. 0.04 mm) were seen on 1st-fraction CBCT in the same-day group (p = 0.0039; p = 0.0002). Per dosimetry recalculated on 1st fraction CBCT, five (D3 cc and D50%) versus one (D50%) rectal dose parameters were exceeded in the same-day and delayed groups, respectively, and 10 versus one parameters had a relative increase of ≥ 20%. Conclusion: Due to the evolving anatomic changes in the days following hydrogel placement, same-day simulation scanning may introduce unintended variability in rectal dosimetry at the time of prostate radiotherapy.

The effect of gastric fundus radiation dose on postoperative anastomotic leakage in esophageal cancer.

Introduction: Standard-of-care treatment for locally advanced esophageal carcinoma (LAEC) includes neoadjuvant chemoradiotherapy followed by esophagectomy. A potentially catastrophic surgical complication is the development of a postoperative anastomotic leak. To date, the association with radiation dose exposure had been inconclusive. We examined the correlation between radiation exposure to the gastric fundus and risk of postoperative leakage using contemporary radiation doses and fractionation. Methods: A total of 69 consecutive patients with LAEC who underwent neoadjuvant chemoradiotherapy followed by esophagectomy in our tertiary center were prospectively followed (median, 27 months). Neoadjuvant regimen included 50.4 Gy in 28 fractions with 5-fluorouracil and cisplatin and 41.4 Gy in 23 fractions with carboplatin and paclitaxel. The gastric fundus was contoured and dosimetric and radiation technique parameters were retrospectively evaluated. Results: Of the total number of patients, 71% and 29% had esophageal and gastroesophageal junction (GEJ) tumors, respectively. Fourteen patients (20.3%) experienced anastomotic leaks within a median of 2 days postoperatively, 78.6% of whom had lower third esophagus or GEJ primaries. Mean and minimum fundus dose did not significantly differ between those with and those without leakage (p = 0.42, p = 0.51). Mean fundus V25, V30, and V35 doses were numerically but not statistically higher in those with anastomotic leak (p = 0.58, p = 0.39, and p = 0.30, respectively). No correlation with incidence of leakage was seen between 3D and IMRT treatment modalities. Conclusions: In our comparatively large prospectively collected series of patients treated for LAEC, radiation dose to the gastric fundus during neoadjuvant combination therapy prior to surgery did not correlate with the risk of postoperative anastomotic leak.

Local Failure after Prostate SBRT Predominantly Occurs in the PI-RADS 4 or 5 Dominant Intraprostatic Lesion.

BACKGROUND: A positive post-treatment prostate biopsy following definitive radiotherapy carries significant prognostic implications. OBJECTIVE: To determine whether local recurrences after prostate stereotactic body radiation therapy (SBRT) are associated with the presence of and occur more commonly within the region of a PI-RADS 4 or 5 dominant intra-prostatic lesion (DIL) identified on pre-treatment multi-parametric magnetic resonance imaging (MRI). DESIGN, SETTING, AND PARTICIPANTS: 247 patients with localized prostate cancer treated with SBRT at our institution from 2009-2018 underwent post-treatment biopsies (median time to biopsy: 2.2 years) to evaluate local control. INTERVENTIONS: Prostate SBRT (median 40 Gy in 5 fractions). OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: MRIs were read by a single diagnostic radiologist blinded to other patient characteristics and treatment outcomes. The DIL presence, size, location, and extent were then analyzed to determine associations with the post-treatment biopsy outcomes. RESULTS AND LIMITATIONS: Among patients who underwent post-treatment biopsies, 39/247 (15.8%) were positive for Gleason-gradable prostate adenocarcinoma, of which 35/39 (90%) had a DIL initially present and 29/39 (74.4%) had a positive biopsy within the DIL. Factors independently associated with post-treatment biopsy outcomes included the presence of a DIL (OR 6.95; p = 0.001), radiographic T3 disease (OR 5.23, p < 0.001), SBRT dose ≥40 Gy (OR 0.26, p = 0.003), and use of androgen deprivation therapy (ADT; OR 0.28, p = 0.027). Among patients with a DIL (N = 149), the only factors associated with post-treatment biopsy outcomes included ≥50% percent cores positive (OR 2.4, p = 0.037), radiographic T3 disease (OR 4.04, p = 0.001), SBRT dose ≥40 Gy (OR 0.22, p < 0.001), and use of ADT (OR 0.21, p = 0.014). CONCLUSIONS: Our results suggest that men with PI-RADS 4 or 5 DILs have a higher risk of local recurrence after prostate SBRT and that most recurrences are located within the DIL. PATIENT SUMMARY: We found the presence of a dominant tumor on pre-treatment MRI was strongly associated with residual cancer within the prostate after SBRT and that most recurrences were within the dominant tumor.

First-line programmed death-1 inhibitor treatment for locoregionally advanced or metastatic cutaneous squamous cell carcinoma - A real-world experience from Israel.

Objective: Cutaneous squamous cell carcinoma (cSCC) is the second most common non-melanoma skin cancer worldwide. It is usually treated surgically, with very high cure rates. However, in 3%-7% of cases, cSCC metastasizes to lymph nodes or distant organs. Many of the affected patients are elderly with comorbidities who are not candidates for standard-of-care curative-intent treatment with surgery and/or radio-/chemotherapy. Immune checkpoint inhibitors, which target programmed cell death protein 1 (PD-1) pathways, have recently emerged as a potent therapeutic option. The present report presents the Israeli experience with PD-1 inhibitors for the treatment of loco-regionally advanced or metastatic cSCC in a diverse and elderly population, with or without the addition of radiotherapy. Material and methods: The databases of two university medical centers were retrospectively searched for patients with cSCC treated with the PD-1 inhibitors cemiplimab or pembrolizumab between January 2019 and May 2022. Data on baseline, disease-related, treatment-related, and outcome parameters were collected and analyzed. Results: The cohort included 102 patients of a median age 78.5 years. Evaluable response data were available for 93. The overall response rate was 80.6%: complete response in 42 patients (45.2%) and partial response in 33 (35.5%). Stable disease was recorded in 7 (7.5%) and progressive disease in 11 (11.8%). Median progression-free survival was 29.5 months. Radiotherapy was administered to the target lesion during PD-1 treatment in 22.5% of patients. mPFS was not significantly different in patients who treated with RT than patients how did not (NR vs 18.4 months, HR=0.93, 95%CI: 0.39 - 2.17, p<0.859). Any-grade toxicity was recorded in 57 patients (55%), including grade _3 in 25, of whom 5 (5% of cohort) died. Compared to toxicity-free patients, patients with drug toxicity had better progression-free survival (18.4 months vs not reached, HR=0.33, 95% CI: 0.13-0.82, p=0.012) and higher overall response rate (87% vs 71.8%, p=0.06). Conclusion: This retrospective real-world study showed that PD-1 inhibitors were effective in the treatment of locally advanced or metastatic cSCC and appeared to be amenable for use in elderly or fragile patients with comorbidities. However, the high toxicity warrants consideration against other modalities. Induction or consolidation radiotherapy may improve the results. These findings need to be corroborated in a prospective trial.

Long-term Outcomes from a Phase 1 Dose Escalation Study Using Stereotactic Body Radiotherapy for Patients with Low- or Intermediate-risk Prostate Cancer.

BACKGROUND: Ultrahypofractionated stereotactic body radiation therapy (SBRT) has become a standard treatment intervention for localized prostate cancer. OBJECTIVE: To report final long-term tumor control outcomes and late gastrointestinal (GI) and genitourinary (GU) toxicities from a single-center phase 1 dose escalation study using SBRT for patients with low- or intermediate-risk prostate cancer. DESIGN, SETTING AND PARTICIPANTS: Between 2009 and 2012, 136 patients were enrolled and treated. The initial dose level was 32.5 Gy in five fractions. Doses were then sequentially escalated to 35 Gy, 37.5 Gy, and 40 Gy in five fractions delivered every other day. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: The primary endpoint was late treatment-related toxicity. Secondary endpoints included prostate-specific antigen (PSA) failure. RESULTS AND LIMITATIONS: The median follow-up was 10.5 yr for the 32.5-Gy group, 9.9 yr for the 35-Gy group, 8.2 yr for the 37.5-Gy group, and 7.3 yr for the 40-Gy group. The 8-yr cumulative incidence of PSA failure was 26% for 32.5 Gy, 15% for 35 Gy, 3.4% for 37.5 Gy, and 6.6% for 40 Gy. Higher radiation dose (37.5-40 Gy) and favorable intermediate risk (vs unfavorable intermediate risk) were associated with better PSA recurrence rates (p = 0.011 and 0.002, respectively). The 8-yr actuarial probability rates for survival free from late grade ≥2 toxicity were 94% for GI toxicity and 86% for GU toxicity. No grade 4 events were recorded. Higher dose levels were not associated with higher rates of late grade ≥2 GI (p = 0.2) or GU (p > 0.9) toxicity. CONCLUSIONS: SBRT doses ranging from 32.5 to 40 Gy were associated with low incidence of moderate or severe toxicities. Higher doses resulted in superior disease control outcomes 8 yr after treatment. PATIENT SUMMARY: We investigated the association between the radiotherapy dose used and the rate of control of prostate cancer. We found that higher doses resulted in more favorable outcomes without excess toxicity. This trial is registered on ClinicalTrials.gov as NCT00911118.

Hypofractionated Radiation Therapy (Hypo-RT) for the Treatment of Localized Bladder Cancer.

BACKGROUND: Various radiotherapeutic regimens are used in the treatment of bladder cancer. OBJECTIVE: We aimed to evaluate early toxicity and outcomes associated with hypofractionated radiation therapy (Hypo-RT), 55Gy in 20 fractions. MATERIAL AND METHODS: We identified 40 patients who received definitive Hypo-RT for localized bladder cancer. Most patients were men (62.5%), elderly (median age 82), had high Charlson Comorbidity Index score (median 7, range 4-9) and were nonsurgical candidates (80%). Sixty-eight percent had a macroscopically complete transurethral resection of bladder tumor (TURBT) and 33 patients (82.5%) received concurrent chemotherapy. Acute (< =3mo) and late (>3mo) toxicities were assessed according to CTCAE v4.0. Survival outcomes were estimated using the Kaplan-Meier method. Median follow up after Hypo-RT was 32 months (95% CI: 28-49 months). RESULTS: Overall rates of acute grade 2 genitourinary (GU) and gastrointestinal (GI) toxicities were 40% each, most commonly urinary frequency and diarrhea. Two cases of acute grade 3 GU/GI toxicity occurred. Late grade 2+ toxicity occurred in 3 patients (7.5%): 2 grade 2 GU and 1 grade 3 GI. Seventy-seven percent achieved a complete response (CR). Six patients (20%) developed disease recurrence at a median time of 9.1 months. The estimated 2-year DFS and 2-year DSS rate were 59% (95% CI, 45-78%) and 78% (95% CI, 65-93%), respectively. Receipt of concurrent chemotherapy (p = 0.003) and achieving a CR (p = 0.018) were univariably associated with improved DSS. Tis component was associated with worse DSS (p = 0.015). CONCLUSION: Hypo-RT had a favorable toxicity profile and encouraging cancer control outcomes in this mostly elderly and frail patient cohort.

Health Disparities in Prostate Cancer and Approaches to Advance Equitable Care.

The American Cancer Society estimates approximately 268,490 new cases of prostate cancer and approximately 34,500 deaths caused by prostate cancer in the United States for 2022. Globally, a total of 1,414,259 new cases of prostate cancer and 375,304 related deaths were reported in 2020. Well-documented health disparities and inequities exist along the continuum of care for prostate cancer management-from screening to diagnostic and staging work-up, surveillance, and treatment-ultimately impacting clinical outcomes. This session-based article discusses innovative patient-centered approaches to advance equitable prostate cancer care. It begins with a review of domestic health disparities in diagnostic imaging and radiotherapy for prostate cancer, and it summarizes barriers and solutions to achieving health equity, such as equity metrics and practice quality improvement projects. Next, a global perspective is provided that describes approaches to address financial and geographic barriers to prostate cancer care, including specific examples of strategies that emphasize the use of the cheapest method of care delivery while maintaining outcomes for drug delivery and radiotherapy.

Use of Continuous Positive Airway Pressure (CPAP) to Limit Diaphragm Motion-A Novel Approach for Definitive Radiation Therapy for Inoperable Pleural Mesothelioma: A Pilot Study.

Malignant pleural mesothelioma (MPM) is a deadly disease and radiotherapy (RT) plays an important role in its management. Recent developments in technique have made it is possible to deliver RT to MPM in the intact lung. However, it is imperative to reduce normal lung doses. We present a pilot study examining the use of CPAP and VMAT radiotherapy to reduce toxicity when treating MPM, involving three consecutive patients with MPM, not amenable to surgery, who were treated according to Helsinki committee approval. Patients were simulated using four-dimentional CT simulation with the assistance of CPAP lung inflation, then were treated using both IMRT and VMAT techniques. Radiation lung dose was optimized based on accepted lung dose constraints. Patients were followed for toxicity as well as local control and survival. Results: Three patients were treated with CPAP-based IMRT treatment. These patients tolerated the treatment and DVH constraints were able to be met. The comparison plans among the four VMAT arcs and the IMRT static field treatment were able to accomplish the treatment planning objectives without significant advantages with either technique. The treatment combined with CPAP reduced the normal lung dose in MPM patients with intact lungs. This technique is worthy of further investigation.