Moderate hypofractionated radiotherapy for prostate cancer: 3-year toxicity results of a multicentre randomized phase 3, non-inferiority trial

BACKGROUND AND PURPOSE

Moderate hypofractionated radiotherapy (HFRT) is a standard treatment for prostate cancer patients. We compared 2 moderate HFRT regimens, with a biologically equivalent dose of 80 Gy in 2 Gy fractions, with a modest simultaneous integrated boost to the dominant intraprostatic lesion.

MATERIAL AND METHODS

This is a multicenter, non-inferiority, randomized phase 3 trial with acute toxicity as the primary endpoint, comparing: 56 Gy in 4 weeks (16x3.5 Gy, 4 days/week, Arm A) with 67 Gy in 5 weeks (25x2.68 Gy, 5 days/week, Arm B). The H0 hypothesis is that both regimens are equivalent in terms of acute grade ≥ 2 gastro-intestinal toxicity, defined as a difference in acute grade ≥ 2 gastro-intestinal toxicity of ≤ 10 %. Here we report on acute and late toxicity.

RESULTS

We included 170 patients in Arm A and 172 patients in Arm B. The median follow-up time for all patients was 42 months. Acute grade ≥ 2 gastrointestinal toxicity was reported by 24 % of patients in both groups. Acute grade 2 and 3 urinary toxicity was observed in 52 % and 9 % of patients in Arm A and 53 % and 7 % in Arm B. Late grade 2 and grade ≥ 3 gastrointestinal toxicity occurred in 19 % and 4 % of patients in Arm A compared with 15 % and 4 % in Arm B. Late grade 2 and grade ≥ 3 urinary toxicity was observed in 37 % and 10 % of patients in Arm A and 36 % and 6 % in Arm B.

CONCLUSION

This analysis confirms that both HFRT regimens are safe and equivalent in terms of acute grade ≥ 2 gastrointestinal toxicity.

Multiregion sampling of de novo metastatic prostate cancer reveals complex polyclonality and augments clinical genotyping

De novo metastatic prostate cancer is highly aggressive, but the paucity of routinely collected tissue has hindered genomic stratification and precision oncology. Here, we leveraged a rare study of surgical intervention in 43 de novo metastatic prostate cancers to assess somatic genotypes across 607 synchronous primary and metastatic tissue regions plus circulating tumor DNA. Intra-prostate heterogeneity was pervasive and impacted clinically relevant genes, resulting in discordant genotypes between select primary restricted regions and synchronous metastases. Additional complexity was driven by polyclonal metastatic seeding from phylogenetically related primary populations. When simulating clinical practice relying on a single tissue region, genomic heterogeneity plus variable tumor fraction across samples caused inaccurate genotyping of dominant disease; however, pooling extracted DNA from multiple biopsy cores before sequencing can rescue misassigned somatic genotypes. Our results define the relationship between synchronous treatment-sensitive primary and metastatic lesions in men with de novo metastatic prostate cancer and provide a framework for implementing genomics-guided patient management.

Clinical and Genomic Differences Between Advanced Molecular Imaging-detected and Conventional Imaging-detected Metachronous Oligometastatic Castration-sensitive Prostate Cancer

In metastatic castration-sensitive prostate cancer (mCSPC), disease volume plays an integral role in guiding treatment recommendations, including selection of docetaxel therapy, metastasis-directed therapy, and radiation to the prostate. Although there are multiple definitions of disease volume, they have commonly been studied in the context of metastases detected via conventional imaging (CIM). One such numeric definition of disease volume, termed oligometastasis, is heavily dependent on the sensitivity of the imaging modality. We performed an international multi-institutional retrospective review of men with metachronous oligometastatic CSPC (omCSPC), detected via either advanced molecular imaging alone (AMIM) or CIM. Patients were compared with respect to clinical and genomic features using the Mann-Whitney U test, Pearson's χ2 test, and Kaplan-Meier overall survival (OS) analyses with a log-rank test. A total of 295 patients were included for analysis. Patients with CIM-omCSPC had significantly higher Gleason grade group (p = 0.032), higher prostate-specific antigen at omCSPC diagnosis (8.0 vs 1.7 ng/ml; p < 0.001), more frequent pathogenic TP53 mutations (28% vs 17%; p = 0.030), and worse 10-yr OS (85% vs 100%; p < 0.001). This is the first report of clinical and biological differences between AMIM-detected and CIM-detected omCSPC. Our findings are particularly important for ongoing and planned clinical trials in omCSPC. PATIENT SUMMARY: Metastatic prostate cancer with just a few metastases only detected via newer scanning methods (called molecular imaging) is associated with fewer high-risk DNA mutations and better survival in comparison to metastatic cancer detected via conventional scan methods.

Clinical Application of the Prostate Cancer Radiological Estimation of Change in Sequential Evaluation Score for Reporting Magnetic Resonance Imaging in Men on Active Surveillance for Prostate Cancer

Background

The Prostate Cancer Radiological Estimation of Change in Sequential Evaluation (PRECISE) score has been developed to standardise prostate magnetic resonance imaging (MRI) reporting in men on active surveillance (AS) for prostate cancer (PCa).

Objective

To evaluate the feasibility of PRECISE scoring and assess its diagnostic accuracy.

Design setting and participants

All PCa patients on AS with a baseline MRI and at least one follow-up MRI scan between January 2008 and September 2022 at a single tertiary referral centre were included in a database. The follow-up protocol of the Prostate Cancer International Active Surveillance (PRIAS) study was used. All scans were retrospectively re-reported by a dedicated uroradiologist and appointed a Prostate Imaging Reporting and Data System (version 2.1) and PRECISE score.

Outcome measurements and statistical analysis

Clinically significant progression was defined by histopathological upgrading (on biopsy or radical prostatectomy) to grade group ≥3 and/or evolution to T3 stage. A survival analysis was performed to assess differential progression-free survival (PFS) according to the PRECISE score.

Results and limitations

A total of 188 patients were included for an analysis with a total of 358 repeat MRI scans and 144 repeat biopsies. The median follow-up was 46 mo (interquartile range 21-74). Radiological progression (PRECISE 4-5) had sensitivity, specificity, negative predictive value, and positive predictive value of, respectively, 78%, 70%, 90%, and 49% for clinically significant progression. Four-year PFS was 91% for PRECISE 1-3 versus 66% for PRECISE 4-5 (p < 0.001). In total, 137 patients underwent a confirmation MRI scan within 18 mo after diagnosis. Four-year PFS in this group was 81% for PRECISE 1-3 versus 43% for PRECISE 4-5 (p < 0.001). Limitations include retrospective design and no strict adherence to AS protocol.

Conclusions

Implementation of PRECISE scoring for PCa patients on AS is feasible and offers a prognostic value. Patients with PRECISE score 4-5 on confirmation MRI within 18 mo after diagnosis have a three-fold higher risk of clinically significant progression after 4 yr.

Patient summary

Patients with low-risk prostate cancer can be followed up carefully. In this study, we evaluate the standardised reporting of repeat magnetic resonance imaging scans (using the Prostate Cancer Radiological Estimation of Change in Sequential Evaluation [PRECISE] recommendations). PRECISE scoring is feasible and helps identify patients in need of further treatment.

Transcriptomic Heterogeneity of Metastatic Disease Timing within Metastatic Castration-Sensitive Prostate Cancer

PURPOSE/OBJECTIVE(S)

Metastatic castration-sensitive prostate cancer (mCSPC) is commonly partitioned into high- and low-volume subgroups which have demonstrated differential biology, prognosis, and response to therapy. Timing of metastasis has similarly demonstrated differences in clinical outcomes, however less is known about any potential underlying biologic differences between these disease states. Herein we aim to compare transcriptomic differences between synchronous and metachronous mCSPC and identify any differential responses to therapy.

MATERIALS/METHODS

We performed an international multi-institutional retrospective review of men with mCSPC who completed RNA expression profiling evaluation of their primary tumor. Patients were stratified according to disease timing (synchronous vs metachronous). The primary endpoint was to identify differences in transcriptomic profiles between disease time. Median genomic scores between groups were compared with Mann-Whitney U test. Secondary analyses included determining clinical and transcriptomic variables associated with overall survival (OS) from time of metastasis. Survival analysis was performed with the Kaplan-Meier Method and Multivariable Cox regression.

RESULTS

A total of 252 patients were included with a median follow-up of 39.6 months. Patients with synchronous disease experienced worse 5-yr OS (39% vs 79%, p<0.01) and demonstrated lower median Androgen Receptor Activity (AR-A) (11.78 vs 12.64, p<0.01) and Hallmark Androgen Response (HAR) (3.15 vs 3.32; p<0.01). Multivariable cox-regression identified only high-volume disease (HR = 4.97, 95% CI 2.71-9.10; p<0.01) and HAR score (HR = 0.51, 95% CI 0.28-0.88; p = 0.02 significantly associated with OS. Finally, patients with synchronous (HR = 0.47, 95% CI 0.30-0.72; <0.01) but not metachronous (HR = 1.37, 95% CI 0.50-3.92; p = 0.56) disease were found to have better OS with Androgen Receptor (AR) + non-AR combination therapy as compared to monotherapy (p value for interaction = 0.05).

CONCLUSION

We have demonstrated a potential biologic difference between metastatic timing of mCSPC. Specifically, for patients with low volume disease, those with metachronous low volume disease have a more hormone dependent transcriptional profile and exhibit a better prognosis than synchronous low volume disease.

Whole Slide Imaging-Based Prediction of TP53 Mutations Identifies an Aggressive Disease Phenotype in Prostate Cancer

In prostate cancer, there is an urgent need for objective prognostic biomarkers that identify the metastatic potential of a tumor at an early stage. While recent analyses indicated TP53 mutations as candidate biomarkers, molecular profiling in a clinical setting is complicated by tumor heterogeneity. Deep learning models that predict the spatial presence of TP53 mutations in whole slide images (WSI) offer the potential to mitigate this issue. To assess the potential of WSIs as proxies for spatially resolved profiling and as biomarkers for aggressive disease, we developed TiDo, a deep learning model that achieves state-of-the-art performance in predicting TP53 mutations from WSIs of primary prostate tumors. In an independent multifocal cohort, the model showed successful generalization at both the patient and lesion level. Analysis of model predictions revealed that false positive (FP) predictions could at least partially be explained by TP53 deletions, suggesting that some FP carry an alteration that leads to the same histological phenotype as TP53 mutations. Comparative expression and histologic cell type analyses identified a TP53-like cellular phenotype triggered by expression of pathways affecting stromal composition. Together, these findings indicate that WSI-based models might not be able to perfectly predict the spatial presence of individual TP53 mutations but they have the potential to elucidate the prognosis of a tumor by depicting a downstream phenotype associated with aggressive disease biomarkers.

SIGNIFICANCE

Deep learning models predicting TP53 mutations from whole slide images of prostate cancer capture histologic phenotypes associated with stromal composition, lymph node metastasis, and biochemical recurrence, indicating their potential as in silico prognostic biomarkers. See related commentary by Bordeleau, p. 2809.

Transcriptomic and clinical heterogeneity of metastatic disease timing within metastatic castration-sensitive prostate cancer

BACKGROUND

Metastatic castration-sensitive prostate cancer (mCSPC) is commonly classified into high- and low-volume subgroups which have demonstrated differential biology, prognosis, and response to therapy. Timing of metastasis has similarly demonstrated differences in clinical outcomes; however, less is known about any underlying biologic differences between these disease states. Herein, we aim to compare transcriptomic differences between synchronous and metachronous mCSPC and identify any differential responses to therapy.

PATIENTS AND METHODS

We performed an international multi-institutional retrospective review of men with mCSPC who completed RNA expression profiling evaluation of their primary tumor. Patients were stratified according to disease timing (synchronous versus metachronous). The primary endpoint was to identify differences in transcriptomic profiles between disease timing. The median transcriptomic scores between groups were compared with the Mann-Whitney U test. Secondary analyses included determining clinical and transcriptomic variables associated with overall survival (OS) from the time of metastasis. Survival analysis was carried out with the Kaplan-Meier method and multivariable Cox regression.

RESULTS

A total of 252 patients were included with a median follow-up of 39.6 months. Patients with synchronous disease experienced worse 5-year OS (39% versus 79%; P < 0.01) and demonstrated lower median androgen receptor (AR) activity (11.78 versus 12.64; P < 0.01) and hallmark androgen response (HAR; 3.15 versus 3.32; P < 0.01). Multivariable Cox regression identified only high-volume disease [hazard ratio (HR) = 4.97, 95% confidence interval (CI) 2.71-9.10; P < 0.01] and HAR score (HR = 0.51, 95% CI 0.28-0.88; P = 0.02) significantly associated with OS. Finally, patients with synchronous (HR = 0.47, 95% CI 0.30-0.72; P < 0.01) but not metachronous (HR = 1.37, 95% CI 0.50-3.92; P = 0.56) disease were found to have better OS with AR and non-AR combination therapy as compared with monotherapy (P value for interaction = 0.05).

CONCLUSIONS

We have demonstrated a potential biologic difference between metastatic timing of mCSPC. Specifically, for patients with low-volume disease, those with metachronous low-volume disease have a more hormone-dependent transcriptional profile and exhibit a better prognosis than synchronous low-volume disease.

Vulvar pagetoid urothelial intraepithelial neoplasia: a case report

BACKGROUND

Pagetoid urothelial intraepithelial neoplasia (PUIN) is a form of secondary Extramammary Paget Disease (EMPD). It is a rare malignant condition seen on the female genitalia synchronous or metachronous with bladder cancer (BC).

CASE PRESENTATION

A 66-year-old female presented with PUIN at the labia minora 2 years after an open anterior pelvic exenteration with ileal conduit urinary diversion for carcinoma in situ (CIS) of the bladder. PUIN of the vulva and vagina was confirmed by a punch biopsy and the patient underwent a radical vaginectomy with urethrectomy and inguinal sentinel node procedure. Immunohistochemically EMPD was identified by the expression tumor protein 63 (p63), cytokeratin 7, and cytokeratin 20 (CK20).

CONCLUSIONS

PUIN is a rare but distinct clinical entity as a form of secondary EMPD which can be differentiated from primary EMPD based on medical history, histology, and immunohistochemistry.

WNT Pathway Mutations in Metachronous Oligometastatic Castration-Sensitive Prostate Cancer

PURPOSE

WNT signaling is a cellular pathway that has been implicated in the development and progression of prostate cancer. Oligometastatic castration-sensitive prostate cancer (omCSPC) represents a unique state of disease in which metastasis-directed therapy (MDT) has demonstrated improvement in progression-free survival. Herein, we investigate the clinical implications of genomic alterations in the WNT signaling cascade in men with omCSPC.

METHODS AND MATERIALS

We performed an international multi-institutional retrospective study of 277 men with metachronous omCSPC who underwent targeted DNA sequencing of their primary/metastatic tumor. Patients were classified by presence or absence of pathogenic WNT pathway mutations (in the genes APC, RNF43, and CTNNB1). Pearson χ2 and Mann-Whitney U tests were used to determine differences in clinical factors between genomic strata. Kaplan-Meier survival curves were generated for radiographic progression-free survival and overall survival, stratified according to WNT pathway mutation status.

RESULTS

A pathogenic WNT pathway mutation was detected in 11.2% of patients. Patients with WNT pathway mutations were more likely to have visceral metastases (22.6% vs 2.8%; P < .01) and less likely to have regional lymph node metastases (29.0% vs 50.4%; P = .02). At time of oligometastasis, these patients were treated with MDT alone (33.9%), MDT + limited course of systemic therapy (20.6%), systemic therapy alone (22.4%), or observation (defined as no treatment for ≥6 months after metastatic diagnosis). Multivariable cox regression demonstrated WNT pathway mutations associated with significantly worse overall survival (hazard ratio, 3.87; 95% confidence interval, 1.25-12.00).

CONCLUSIONS

Somatic WNT pathway alterations are present in approximately 11% of patients with omCSPC and are associated with an increased likelihood of visceral metastases. Although these patients have a worse natural history, they may benefit from MDT.

Genomic determinants of patterns of failure in metachronous oligometastatic castration-sensitive prostate cancer

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Background: Oligometastatic castration-sensitive prostate cancer (omCSPC) represents an early state along the progression of metastatic disease in which patients experience improved outcomes compared to those with higher disease burden. Despite the generally more indolent nature, much heterogeneity still exists with some patients experiencing a more aggressive clinical course unexplained by clinical features alone. Here we correlate tumor genomics with modes of progression (MOP) and patterns of failure (POF) following treatment for omCSPC. Methods: We performed an international multi-institutional retrospective study of men treated for metachronous omCSPC, who underwent tumor next generation sequencing (NGS) with at least 1 year of follow-up. Descriptive POF and MOP were reported with respect to presence of genomic alterations in pathways of interest. Genomic pathways of interest included TP53, SPOP, WNT ( APC, CTNNB1, RNF43), DNA double strand break repair, cell cycle genes ( Rb1, CCND1–3, CDKN1B, and CDKN2A), and PI3K/AKT/mTOR. MOP were defined as oligoprogression (1-3 lesions), polyprogression (≥4 lesions), or long-term control (LTC, no radiographic progression at last follow-up). POF included location of lesions at first failure. Overall survival (OS) was calculated by the Kaplan-Meier method. Genomic associations with patterns/modes of failure were compared with chi-square test. Results: 221 patients were included for analysis with the majority having either 1 (47.5%) or 2 (27.3%) metastatic lesions at oligometastasis. 5-yr OS was associated with MOP 92% vs 89% vs 69% (p<0.01) for LTC, oligo- and polyprogression respectively. TP53 mutations were associated with significantly lower rates of LTC (24.4% vs 46%, p<0.01) and cell cycle mutations associated with high rates of polyprogression (36.7% vs 15.7%, p<0.01). With respect to POF, bone failure was significantly more common within tumors harboring mutations in TP53 (41.2% vs 23.1%, p=0.01) and less common with SPOP mutations (4.2% vs 27.8%, p=0.02). Finally, visceral failures were more common in tumors harboring either WNT pathway (20% vs 5.1%, p<0.01) or SPOP (17.4% vs 5.2%, p=0.04) mutations. Notably, SPOP and WNT pathway mutations cluster together (p<0.01). Conclusions: Tumor genomics provides novel insight into patterns of failure and modes of progression following treatment for metachronous omCSPC. Patients with TP53 and cell cycle mutations have a higher likelihood of progression and TP53, SPOP, and WNT pathway mutations may have a role in metastatic organotropism.

Long-Term Outcomes and Genetic Predictors of Response to Metastasis-Directed Therapy Versus Observation in Oligometastatic Prostate Cancer: Analysis of STOMP and ORIOLE Trials

Clinical trials frequently include multiple end points that mature at different times. The initial report, typically based on the primary end point, may be published when key planned co-primary or secondary analyses are not yet available. Clinical Trial Updates provide an opportunity to disseminate additional results from studies, published in JCO or elsewhere, for which the primary end point has already been reported.The initial STOMP and ORIOLE trial reports suggested that metastasis-directed therapy (MDT) in oligometastatic castration-sensitive prostate cancer (omCSPC) was associated with improved treatment outcomes. Here, we present long-term outcomes of MDT in omCSPC by pooling STOMP and ORIOLE and assess the ability of a high-risk mutational signature to risk stratify outcomes after MDT. The primary end point was progression-free survival (PFS) calculated using the Kaplan-Meier method. High-risk mutations were defined as pathogenic somatic mutations within ATM, BRCA1/2, Rb1, or TP53. The median follow-up for the whole group was 52.5 months. Median PFS was prolonged with MDT compared with observation (pooled hazard ratio [HR], 0.44; 95% CI, 0.29 to 0.66; P value < .001), with the largest benefit of MDT in patients with a high-risk mutation (HR high-risk, 0.05; HR no high-risk, 0.42; P value for interaction: .12). Within the MDT cohort, the PFS was 13.4 months in those without a high-risk mutation, compared with 7.5 months in those with a high-risk mutation (HR, 0.53; 95% CI, 0.25 to 1.11; P = .09). Long-term outcomes from the only two randomized trials in omCSPC suggest a sustained clinical benefit to MDT over observation. A high-risk mutational signature may help risk stratify treatment outcomes after MDT.

Evaluating the Impact of Prostate Only Versus Pelvic Radiotherapy for Pathological Node-positive Prostate Cancer: First Results from the Multicenter Phase 3 PROPER Trial

BACKGROUND

The optimal treatment for patients with pathological node-positive (pN1) prostate cancer (PCa) is unclear.

OBJECTIVE

To evaluate whether whole-pelvis radiotherapy (WPRT) improves clinical relapse-free survival (cRFS) in comparison to prostate-only radiotherapy (PORT) in pN1 PCa.

DESIGN, SETTING, AND PARTICIPANTS

PROPER was a phase 3 trial randomizing patients to WPRT or PORT. All patients had pN1cM0 PCa with fewer than five lymph nodes involved.

INTERVENTION

All patients underwent pelvic lymph node dissection followed by radical prostatectomy/primary radiotherapy + 2 yr of androgen deprivation therapy (ADT). Patients were randomized to PORT (arm A) or WPRT (arm B).

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

The primary outcome was cRFS. The secondary endpoints were overall survival (OS), biochemical relapse-free survival (bRFS), and toxicity. The study was stopped because of poor accrual in June 2021 after the inclusion of 69 patients. We report on OS, bRFS, cRFS, and acute and late toxicity.

RESULTS AND LIMITATIONS

The median follow-up was 30 mo in arm A (n = 33) and 36 mo in arm B (n = 31). The 3-yr OS rate was 92% ± 5% in arm A and 93% ± 5% in arm B (p = 0.61). None of the patients died of PCa. The 3-yr bRFS was 79% ± 9% in arm A and 92% ± 5% in arm B (p = 0.08). The 3-yr cRFS rate was 88% ± 6% in arm A and 92% ± 5% in arm B (p = 0.31). No pelvic recurrence was observed in arm B. Acute grade 2 gastrointestinal toxicity was higher with WPRT (15% in arm A vs 45% in arm B; p = 0.03). Limitations are the early closure because of poor accrual and the limited follow-up.

CONCLUSIONS

The results of our trial are hypothesis-generating but add evidence supporting the recommendation to offer WPRT to patients with pN1 PCa. However, WPRT is associated with more acute gastrointestinal toxicity.

PATIENT SUMMARY

We looked at the impact of radiotherapy to the whole pelvis (WPRT) for patients with prostate cancer that had spread to the lymph nodes. Although the trial was closed early because of poor enrolment, we found that WPRT improves survival free from relapse, and no recurrences were observed in the pelvis. WPRT is associated with more acute side effects on the gastrointestinal system in comparison to radiotherapy to just the prostate.

Adjuvant Radiotherapy After Radical Cystectomy for Patients with High-risk Muscle-invasive Bladder Cancer: Results of a Multicentric Phase II Trial

BACKGROUND

High-risk muscle-invasive bladder cancer (MIBC) has a poor prognosis. Old trials showed that external beam radiotherapy (EBRT) after radical cystectomy (RC) decreases the incidence of local recurrences but induces severe toxicity.

OBJECTIVE

To evaluate the toxicity and local control rate after adjuvant EBRT after RC delivered with volumetric arc radiotherapy.

DESIGN, SETTING, AND PARTICIPANTS

This is a multicentric phase 2 trial. From August 2014 till October 2020, we treated 72 high-risk MIBC patients with adjuvant EBRT after RC. High-risk MIBC is defined as ≥pT3-MIBC ± lymphovascular invasion, fewer than ten lymph nodes removed, pathological positive lymph nodes, or positive surgical margins.

INTERVENTION

Patients received 50 Gy in 25 fractions with intensity-modulated radiotherapy to the pelvic lymph nodes ± cystectomy bed.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

The primary outcome is acute toxicity. We report on local relapse-free rate (LRFR), clinical relapse-free survival (CRFS), overall survival (OS), and bladder cancer-specific survival (BCSS).

RESULTS AND LIMITATIONS

The median follow-up is 18 mo. Forty-two patients (61%) developed acute grade 2 gastrointestinal (GI) toxicity. Four patients (6%) had acute grade 3 GI toxicity. One patient had grade 5 diarrhea and vomiting due to obstruction at 1 mo. Two-year probabilities of developing grade ≥3 and ≥2 GI toxicity were 17% and 76%, respectively. Urinary toxicity, assessed in 17 patients with a neobladder, was acceptable with acute grade 2 and 3 urinary toxicity reported in 53% (N = 9) and 18% (N = 3) of the patients, respectively. The 2-yr LRFR is 83% ± 5% and the 2-yr CRFS rate is 43% with a median CRFS time of 12 mo (95% confidence interval: 3-21 mo). Two-year OS and BCSS are 52% ± 7% and 62% ± 7%, respectively. Shortcomings are the nonrandomized study design and limited follow-up.

CONCLUSIONS

Adjuvant EBRT after RC can be administered without excessive severe toxicity.

PATIENT SUMMARY

In this report, we looked at the incidence of toxicity and local control after adjuvant external beam radiotherapy (EBRT) following radical cystectomy (RC) in high-risk muscle-invasive bladder cancer patients. We found that adjuvant EBRT was feasible and resulted in good local control. We conclude that these data support further enrollment of patients in ongoing trials to evaluate the place of adjuvant EBRT after RC.

Abstract 41: Multi-focal genomic dissection of synchronous primary and metastatic tissue from de novo metastatic prostate cancer

Background: 10% of newly diagnosed prostate cancer presents with metastases. Known as de novo metastatic castrate-sensitive prostate cancer (mCSPC), it is disproportionally responsible for &gt;50% of prostate cancer deaths. Cancer genotyping can identify vulnerabilities exploitable by targeted therapies, and promises to help prognosticate. However, tissue from de novo mCSPC is scarce; neither prostatectomy nor metastatic biopsy is standard, and it is unknown if diagnostic biopsies are representative of synchronous metastases. The potential for plasma circulating tumor DNA (ctDNA) to inform on tumor genotype is also unknown.

Methods: We performed comprehensive pathological and genomic assessment of all spatially or phenotypically-distinct tumor foci (n=523) in 43 patients with de novo mCSPC who underwent prostatectomy, pelvic lymph node dissection, and plasma collection.

Results: 91% (478/523) of tissue foci had evidence of prostate cancer by targeted DNA sequencing, with a median tumor fraction of 48%. When modeling random selection of a single primary foci (mirroring biopsy tissue availability in clinic), tumor fraction was &lt;20% in 19% of patients. Only 46% of plasma cell-free DNA samples prior to systemic therapy had a ctDNA fraction above 0.3% (limit of detection); median tumor fraction of 5% in samples with confirmed ctDNA. We observed recurrent alterations in major driver genes, including TP53, FOXA1, PTEN, and RB1, and the genomic landscape was very similar to published cohorts of castration-resistant prostate cancer (excluding AR). Primary site genomic heterogeneity was pervasive, including secondary (clonally distinct) prostate cancer populations in 14% of patients. Polyclonal seeding of metastases was detected in 26% of patients. Biallelic inactivation of TP53, PTEN, and/or RB1 was observed in 63% of tumors, and was frequently found in synchronous metastases and ctDNA. The two patients with compound disruption of TP53, PTEN, and RB1 experienced rapid progression to castration-resistance and death within two years of diagnosis, despite initial low-risk clinical features. Across the cohort, biallelic disruption of TP53 together with high-risk clinical features at diagnosis was associated with rapid progression (HR 4.64 (95% CI: 1.70-12.69); P = 0.003).

Conclusions: One fifth of patients with de novo mCSPC have pervasive low tumor fraction in their primary tumor and blood plasma. Many tumors exhibit spatial heterogeneity within the primary site, with evidence of multiple clones seeding metastases. This data raises concerns about accurate tumor genotyping in routine clinical practice where needle biopsy specimens are the only available tissue for profiling. Nevertheless, some de novo mCSPC are marked by aggressive genomics and experience rapid progression to lethal disease, suggesting that tailored multi-focal genomic profiling can further segment the disease.

Citation Format: Evan Warner, Kim Van der Eecken, Andrew J. Murtha, Edmond M. Kwan, Sarah W. Ng, Xinyi E. Chen, Cecily Q. Bernales, Grainne Donnellan, Elena Schonlau, Sofie Verbeke, Nicolaas Lumen, Jo Van Dorpe, Gillian Vandekerkhove, Elie Ritch, Matti Annala, Bram De Laere, Piet Ost, Alexander W. Wyatt. Multi-focal genomic dissection of synchronous primary and metastatic tissue from de novo metastatic prostate cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 41.

Long-term outcomes and genetic predictors of response to metastasis-directed therapy versus observation in oligometastatic castration-sensitive prostate cancer: A pooled analysis of the STOMP and ORIOLE trials

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Background: Prospective reports suggest metastasis directed therapy (MDT) in oligometastatic castration sensitive prostate cancer (omCSPC) is associated with improved treatment outcomes. Here we present long term outcomes of the phase II STOMP and ORIOLE trials and assess the ability of a high-risk (HiRi) mutational signature to provide prognostic and predictive information regarding MDT response. Methods: Patients with omCSPC (< 3 lesions) enrolled on STOMP (n = 62) and ORIOLE (n = 54) randomized to MDT or observation were pooled. The primary endpoint was progression-free survival (PFS) defined as either PSA or radiographic progression, initiation of androgen deprivation, or death. Secondary endpoint was radiographic PFS (rPFS) defined as radiographic progression or death. Both were calculated using the Kaplan-Meier method and stratified by treatment group. Next generation sequencing (NGS) was performed to identify a HiRi mutational signature defined as pathogenic mutations within ATM, BRCA1/2, Rb1, or TP53. Cox proportional hazards regressions were fit to calculate hazard ratios (HR) and assess the prognostic and predictive values of HiRi mutational status. Results: Median follow-up was 52.5 months. Median PFS was prolonged with MDT (11.9 months) compared to observation (5.9 months) with a pooled HR of 0.44 (95% CI, 0.29 – 0.66, p-value < 0.001). MDT was associated with PSA decrease in a majority of patients (84%) as compared to the observation group (41%). On NGS, the incidence of a pathogenic mutation in a HiRi gene was 24.3%. HiRi mutation was prognostic for PFS -- in those without a HiRi mutation median PFS was 11.9 months compared to 5.9 months in those with a HiRi mutation (HR of 1.74, p = 0.06). HiRi mutation was also prognostic for rPFS -- those without a high-risk mutation experienced median rPFS of 22.6 months compared to 10.0 months in those with a high-risk mutation (HR 2.62, p < 0.01). Tumors without a HiRi mutation treated with MDT experienced the longest PFS (13.4 months) while those with a HiRi randomized to observation experienced the shortest PFS (2.8 months). Stratifying by both treatment arms and HiRi status appeared to show a differential benefit to MDT, with those with HiRi mutations experiencing a larger relative magnitude of benefit to treatment: (HiRi mutation: HR of 0.05, p < 0.01; no HiRi mutation: HR of 0.42, p = 0.01; p interaction, 0.12) suggesting a HiRi mutational status can provide information regarding differential response to treatment. Conclusions: Long-term outcomes from the only two randomized trials in omCSPC suggest a sustained benefit to MDT over observation. A HiRi mutational signature appears prognostic for outcomes in omCSPC and those with HiRi might have a relatively larger magnitude of response to MDT. Future studies are needed to optimize patient selection. Clinical trial information: NCT02680587.

Genomic Features of Lung-Recurrent Hormone-Sensitive Prostate Cancer

PURPOSE

Pulmonary involvement is rare in metastatic hormone-sensitive prostate cancer (mHSPC) that recurs after treatment for localized disease. Guidelines recommend intensive systemic therapy, similar to patients with liver metastases, but some lung-recurrent mHSPC may have good outcomes. Genomic features of lung metastases may clarify disease aggression, but are poorly understood since lung biopsy is rarely performed. We present a comparative assessment of genomic drivers and heterogeneity in metachronous prostate tumors and lung metastases.

METHODS

We leveraged a prospective functional imaging study of 208 biochemically recurrent prostate cancers to identify 10 patients with lung-recurrent mHSPC. Histologic diagnosis was attained via thoracic surgery or fine-needle lung biopsy. We retrieved clinical data and performed multiregion sampling of primary tumors and metastases. Targeted and/or whole-exome sequencing was applied to 46 primary and 32 metastatic foci.

RESULTS

Unusually for mHSPC, all patients remained alive despite a median follow-up of 11.5 years. Several patients experienced long-term freedom from systemic treatment. The genomic landscape of lung-recurrent mHSPC was typical of curable prostate cancer with frequent PTEN, SPOP, and chromosome 8p alterations, and there were no deleterious TP53 and DNA damage repair gene mutations that characterize aggressive prostate cancer. Despite a long median time to recurrence (76.8 months), copy number alterations and clonal mutations were highly conserved between metastatic and primary foci, consistent with intrapatient homogeneity and limited genomic evolution.

CONCLUSION

In this retrospective hypothesis-generating study, we observed indolent genomic etiology in selected lung-recurrent mHSPC, cautioning against grouping these patients together with liver or bone-predominant mHSPC. Although our data do not generalize to all patients with lung metastases, the results encourage prospective efforts to stratify lung-recurrent mHSPC by genomic features.

Shallow whole-genome sequencing: a useful, easy to apply molecular technique for CNA detection on FFPE tumor tissue-a glioma-driven study

Copy number alterations (CNAs) have increasingly become part of the diagnostic algorithm of glial tumors. Alterations such as homozygous deletion of CDKN2A/B, 7 +/ 10 - chromosome copy number changes or EGFR amplification are predictive of a poor prognosis. The codeletion of chromosome arms 1p and 19q, typically associated with oligodendroglioma, implies a more favorable prognosis. Detection of this codeletion by the current diagnostic standard, being fluorescence in situ hybridization (FISH), is sometimes however subject to technical and interpretation problems. In this study, we evaluated CNA detection by shallow whole-genome sequencing (sWGS) as an inexpensive, complementary molecular technique. A cohort of 36 glioma tissue samples, enriched with "difficult" and "ambiguous" cases, was analyzed by sWGS. sWGS results were compared with FISH assays of chromosomes 1p and 19q. In addition, CNAs relevant to glioblastoma diagnosis were explored. In 4/36 samples, EGFR (7p11.2) amplifications and homozygous loss of CDKN2A/B were identified by sWGS. Six out of 8 IDH-wild-type glioblastomas demonstrated a prognostic chromosome 7/chromosome 10 signature. In 11/36 samples, local interstitial and terminal 1p/19q alterations were detected by sWGS, implying that FISH's targeted nature might promote false arm-level extrapolations. In this cohort, differences in overall survival between patients with and without codeletion were better pronounced by the sequencing-based distinction (likelihood ratio of 7.48) in comparison to FISH groupings (likelihood ratio of 0.97 at diagnosis and 1.79 ± 0.62 at reobservation), suggesting sWGS is more accurate than FISH. We recognized adverse effects of tissue block age on FISH signals. In addition, we show how sWGS reveals relevant aberrations beyond the 1p/19q state, such as EGFR amplification, combined gain of chromosome 7 and loss of chromosome 10, and homozygous loss of CDKN2A/B. The findings presented by this study might stimulate implementation of sWGS as a complementary, easy to apply technique for copy number detection.

GSK3-beta as a candidate therapeutic target in soft tissue sarcomas

Soft tissue sarcoma (STS) is a predominantly fatal rare malignancy with inadequate treatment options. Glycogen synthase kinase 3β (GSK-3β) is an emerging target in human malignancies. Its therapeutic relevance in STS is unknown. We analyzed the prognostic impact of GSK-3β gene and protein expression in two independent cohorts of patients with STS. We then treated STS cell lines and mice xenografts with a novel GSK-3 inhibitor 9-ING-41 alone or in combination with chemotherapy. We demonstrated that 9-ING-41 treatment induced significant STS cells apoptosis and was synergistic in vivo when combined with chemotherapy. Mechanistically, 9-ING-41 induces significant apoptosis of STS cells via suppression of NF-κB-mediated X-linked inhibitor of apoptosis protein (XIAP) expression. These data support the inclusion of patients with STS in clinical studies of 9-ING-41 alone and in combination with chemotherapy.

Tissue- and Blood-derived Genomic Biomarkers for Metastatic Hormone-sensitive Prostate Cancer: A Systematic Review

CONTEXT

Multiple studies have reported on the genomic characteristics of metastatic hormone-sensitive prostate cancer (mHSPC). The impact of these findings on prognostication, treatment selection, and clinical trial design remains unclear.

OBJECTIVE

To summarise genomic alteration prevalences in liquid and/or tissue biopsies, infer their clinical implications, and compare genomic alteration frequencies across different disease states and clinical phenotypes.

EVIDENCE ACQUISITION

The PubMed and Web of Knowledge databases were systematically searched up to January 2021. Quality assessment was performed using the Joanna Briggs Institute Critical Appraisal tools.

EVIDENCE SYNTHESIS

In total, 11 studies encompassing 1682 mHSPC patients were included. High-volume disease was associated with more frequent alterations in TP53, DNA damage repair, and Wnt pathways. Tumours from patients with de novo mHSPC were enriched for alterations in TP53 and CDK12 compared with recurrent disease. Alterations in AR, TP53, cell cycle signalling, and MYC were associated with a poorer clinical outcome. A comparative analysis of gene alteration frequencies across disease states revealed a relative increase from localised to castration-resistant tumours, with noteworthy enrichment of CTNNB1 alterations in mHSPC (5%), which warrants further investigation. This study was limited by variability in methodology and definitions used among the eligible studies, including differences in sequencing methods, analytes (being either tissue or liquid), alteration calling thresholds, and target patient populations with a relative under-representation of recurrent metastatic disease.

CONCLUSIONS

Several genomic alterations are associated with differential prognosis and clinical phenotypes in mHSPC. We urge that emerging data on these potential predictive biomarkers must be validated in biomarker-driven randomised controlled trials before any clinical implementation. Alignment of the assay methodology and reporting will be critical for ensuring rapid scalability.

PATIENT SUMMARY

We reviewed current data on genomic alterations of metastatic hormone-sensitive prostate cancer, and summarised key genomic subtypes that associate with specific clinical phenotypes and treatment outcomes.

Evaluating the impact of 18F-FDG-PET-CT on risk stratification and treatment adaptation for patients with muscle-invasive bladder cancer (EFFORT-MIBC): a phase II prospective trial

Background

The outcome of patients with muscle-invasive bladder cancer (MIBC) remains poor, despite aggressive treatments. Inadequate primary staging, classically performed by computed tomography (CT)-imaging, could lead to inappropriate treatment and might contribute to these poor results. Although not (yet) adapted by international guidelines, several reports have indicated the superiority of ¹⁸F-fluorodeoxyglucose-positron emission tomography-CT (¹⁸F-FDG-PET-CT) compared to CT in the detection of lymph node and distant metastases. Thereby the presence of extra-vesical disease on ¹⁸F-FDG-PET-CT has been correlated with a worse overall survival. This supports the hypothesis that ¹⁸F-FDG-PET-CT is useful in stratifying MIBC patients and that adapting the treatment plan accordingly might result in improved outcome.

Methods

EFFORT-MIBC is a multicentric prospective phase II trial aiming to include 156 patients. Eligible patients are patients with histopathology-proven MIBC or ≥ T3 on conventional imaging treated with MIBC radical treatment, without extra-pelvic metastases on conventional imaging (thoracic CT and abdominopelvic CT/ magnetic resonance imaging (MRI)). All patients will undergo radical local therapy and if eligible neo-adjuvant chemotherapy. An ¹⁸F-FDG-PET-CT will be performed in addition to and at the timing of the conventional imaging. In case of presence of extra-pelvic metastasis on ¹⁸F-FDG-PET-CT, appropriate intensification of treatment with metastasis-directed therapy (MDT) (in case of ≤3 metastases) or systemic immunotherapy (> 3 metastases) will be provided. The primary outcome is the 2-year overall survival rate. Secondary endpoints are progression-free survival, distant metastasis-free survival, disease-specific survival and quality of life. Furthermore, the added diagnostic value of ¹⁸F-FDG-PET-CT compared to conventional imaging will be evaluated and biomarkers in tumor specimen, urine and blood will be correlated with primary and secondary endpoints.

Discussion

This is a prospective phase II trial evaluating the impact of ¹⁸F-FDG-PET-CT in stratifying patients with primary MIBC and tailoring the treatment accordingly. We hypothesize that the information on the pelvic nodes can be used to guide local treatment and that the presence of extra-pelvic metastases enables MDT or necessitates the early initiation of immunotherapy leading to an improved outcome.

Trial registration

The Ethics Committee of the Ghent University Hospital (BC-07456) approved this study on 11/5/2020. The trial was registered on ClinicalTrials.gov (NCT04724928) on 21/1/2021.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-021-08861-x.

The Role of Cytoreductive Radical Prostatectomy in the Treatment of Newly Diagnosed Low-volume Metastatic Prostate Cancer. Results from the Local Treatment of Metastatic Prostate Cancer (LoMP) Registry

Background

Radiotherapy to the prostate (RTp) prolongs survival for patients with low-volume, newly diagnosed metastatic prostate cancer (ndmPC).

Objective

to evaluate whether cytoreductive radical prostatectomy (cRP) is equally beneficial as RTp in low-volume ndmPC.

Design, setting, and participants

A multicenter prospective registry was established in 2014 to observe patients with ndmPC. Eligible patients were offered cRP or RTp. For this study we selected only patients with low-volume ndmPC (n = 109). Of these, 48, 26, and 35 patients underwent cRP, RTp, and no local therapy (NLT), respectively. Median follow-up was 32 mo (interquartile range 16–49).

Intervention

cRP was compared with RTp and NLT.

Outcome measurements and statistical analysis

Overall survival (OS), cancer-specific survival (CSS), and local event–free survival (LEFS) were calculated using the Kaplan-Meier method. Factors prognostic for OS were identified using univariate and multivariate Cox regression analysis.

Results and limitations

The 2-yr OS was 93%, 100%, and 69%, and 2-yr CSS was 93%, 100%, and 75% for cRP, RTp, and NLT, respectively. The cRP and RTp groups had better OS compared to NLT and there was no significant difference between cRP and RTp. The 2-yr LEFS was 92%, 77%, and 60% for cRP, RTp, and NLT, respectively. The cRP group had better LEFS compared to RTp and NLT, and there was no significant difference between RTp and NLT. Advanced tumor stage, Eastern Cooperative Oncology Group performance status ≥2, and NLT were negative prognostic factors for OS. The main limitation is selection of fitter patients with less advanced tumors for cRP and the small sample size.

Conclusions

For selected patients with low-volume ndmPC, cRP is able to achieve similar OS and CSS to RTp. cRP is effective in preventing local events due to disease progression.

Patient summary

Patients with a low volume of newly diagnosed prostate cancer that has spread beyond the prostate gland might benefit from removal of the prostate, which we found was as effective as radiotherapy to the prostate in prolonging survival. Removal of the prostate is effective in preventing urinary problems caused by cancer progression.

Retrospective analysis of multiparametric MRI to predict complete pathologic response after neo-adjuvant chemotherapy for muscle invasive bladder cancer

e16535

Background: Muscle invasive bladder cancer (MIBC) is a life-threatening disease. Treatment is multimodal combining neo-adjuvant cisplatin-based chemotherapy (NAC) and radical cystectomy (RC). Accurately predicting complete pathologic response (pCR) using multiparametric MRI (mpMRI) could impact peri-operatively treatment. Methods: MIBC patients receiving NAC were evaluated at our institution with mpMRI before, after 2 cycles and after 4 cycles of dose dense MVAC (ddMVAC). Response after 4 cycles was retrospectively assessed using the method earlier described by Necchi et al with blinding of the readers for the pathological result of RC. Two radiologists independently evaluated 3 questions: residual disease at T1/T2-weighted images, presence of spots of restrictive diffusion within the bladder wall on diffusion-weighted imaging, and presence of focal contrast enhancement in the bladder wall on dynamic contrast enhanced images. Radiographic complete response (rCR) was defined as “No” on all three questions. Results: A total of 46 patients were identified having received ddMVAC for urothelial MIBC. Six patients did not undergo RC after NAC and were excluded from this analysis. Eleven out of 40 (28%) patients showed a complete pathologic response (ypT0). Baseline characteristics were similar compared to non-complete pathologic responders ( > ypT0), with the exception of hydronephrosis (9% in ypT0 vs. 52% in > ypT0). mpMRI questions could be assessed in 37 of 40 patients (93%). rCR was seen in 5 patients and was significantly associated with pCR (1-sided p value 0.021). Although sensitivity was low (36%), specificity was very high (96%) of this 3-step assessment. Positive likelihood ratio was 9.45, negative likelihood ratio 0.66. Concordance of assessment was very high. Conclusions: Using the 3-step imaging approach of Necchi et al, mpMRI can predict pCR after neo-adjuvant cisplatin-based chemotherapy with high specificity but low sensitivity. mpMRI should be included in future trials of multimodal management of MIBC and is an important predictive asset in routine clinical management.[Table: see text]

Shallow-depth sequencing of cell-free DNA for Hodgkin and diffuse large B-cell lymphoma (differential) diagnosis: a standardized approach with underappreciated potential

Shallow-depth sequencing of cell-free DNA, an inexpensive and standardized approach to obtain molecular information on tumors non-invasively, has been insufficiently explored for the diagnosis of lymphoma and disease follow-up. This study collected 318 samples, including longitudinal liquid and paired solid biopsies, from a prospectively- recruited cohort of 38 Hodgkin lymphoma (HL) and 85 aggressive B-cell non-HL patients, represented by 81 diffuse large B-cell lymphoma (DLBCL) cases. Following sequencing, copy number alterations and viral read fractions were derived and analyzed. At diagnosis, liquid biopsies showed detectable copy number alterations in 84.2% of HL patients (88.6% for classical HL) and 74.1% of DLBCL patients. Of the DLBCL patients, copy number profiles between liquid-solid pairs were highly concordant (r=0.815±0.043); and, compared to tissue, HL liquid biopsies had abnormalities with higher amplitudes (P=0.010). This implies that tumor DNA is more abundant in plasma. Additionally, 39.5% of HL and 13.6% of DLBCL cases had a significantly elevated number of plasma Epstein-Barr virus DNA fragments, achieving a sensitivity of 100% compared to the current standard. A longitudinal analysis determined that, when detectable, copy number patterns were similar across (re)staging moments in refractory or relapsed patients. Further, the overall profile anomaly correlated highly with the total metabolic tumor volume (P<0.001). To conclude, as a proof of principle, we demonstrate that liquid biopsy-derived copy numbers can aid diagnosis: e.g., by differentiating HL from DLBCL, random forest modeling is represented by an area under the receiver operating characteristic curve of 0.967. This application is potentially useful when tissue is difficult to obtain or when biopsies are small and inconclusive.

CHK1 inhibition in soft-tissue sarcomas: biological and clinical implications

Background

Inhibition of ChK1 appears as a promising strategy for selectively potentiate the efficacy of chemotherapeutic agents in G1 checkpoint-defective tumor cells such as those that lack functional p53 protein. The p53 pathway is commonly dysregulated in soft-tissue sarcomas (STS) through mutations affecting TP53 or MDM2 amplification. GDC-0575 is a selective ATP-competitive inhibitor of CHK1.

Methods

We have performed a systematic screening of a panel of 10 STS cell lines by combining the treatment of GDC-0575 with chemotherapy. Cell proliferation, cell death and cell cycle analysis were evaluated with high throughput assay. In vivo experiments were carried out by using TP53-mutated and TP53 wild-type patient-derived xenograft models of STS. Clinical activity of GDC-0575 combined with chemotherapy in patients with TP53-mutated and TP53 wild-type STS was also assessed.

Results

We found that GDC-0575 abrogated DNA damage-induced S and G2-M checkpoints, exacerbated DNA double-strand breaks and induced apoptosis in STS cells. Moreover, we observed a synergistic or additive effect of GDC-0575 together with gemcitabine in vitro and in vivo in TP53-proficient but not TP53-deficient sarcoma models. In a phase I study of GDC-0575 in combination with gemcitabine, two patients with metastatic TP53-mutated STS had an exceptional, long-lasting response despite administration of a very low dose of gemcitabine whereas one patient with wild-type TP53 STS had no clinical benefit. Genetic profiling of samples from a patient displaying secondary resistance after 1 year showed loss of one preexisting loss-of-function mutation in the helical domain of DNA2.

Conclusion

We provide the first preclinical and clinical evidence that potentiation of chemotherapy activity with a CHK1 inhibitor is a promising strategy in TP53-deficient STS and deserves further investigation in the phase II setting.

Randomized phase I trial of pembrolizumab with neo-adjuvant versus concomitant stereotactic body radiotherapy in metastatic urothelial carcinoma: Clinical and translational results

422

Background: Preclinical data indicates that stereotactic body radiotherapy (SBRT) works synergistically with pembrolizumab, but the effect and potential toxicity might depend on the timing of SBRT. The current study assessed the safety of two different SBRT schedules in combination with pembrolizumab for metastatic urothelial carcinoma (mUC), and explored correlative biomarkers including circulating tumor DNA (ctDNA). Methods: An open-label phase 1 trial was conducted at Ghent University Hospital in patients with mUC to assess the dose-limiting toxicity (DLT) of the combination of pembrolizumab (200mg intravenously, 3-weekly) and SBRT (3x8Gy to the largest lesion). Patients were randomized (1:1) to receive SBRT either prior to the first (arm A) or the third (arm B) cycle of pembrolizumab. Blood was collected throughout the trial for biomarker analysis. Adverse events (AEs) were assessed according to the Common Terminology Criteria for Adverse Events version 4.0. Secondary endpoints included best overall response measured per Response Evaluation Criteria in Solid Tumors v1.1 (RECISTv1.1). The trial was approved by the Ethical Committee of Ghent University Hospital and is registered on ClinicalTrials.gov (NCT02826564). Funding was provided by Merck Sharp & Dohme. Results: Eighteen patients were randomized (nine to each arm) and started trial treatment. No DLT occurred. Treatment-related AEs grade 1-2 occurred in 6/9 and 9/9 patients in arm A and B respectively. One patient in arm B experienced lymphopenia grade 3, unrelated to SBRT. No treatment-related AEs grade 4-5 occurred. An objective response rate as per RECISTv1.1 of 0% and 44·4% was noted in arm A and B respectively. Targeted sequencing of tissue DNA and ctDNA revealed high genomic concordance. A decline in ctDNA was observed in responding patients. Conclusions: Neo-adjuvant and concomitant SBRT combined with pembrolizumab is safe, with potentially superior responses in the latter. ctDNA monitoring is feasible during disease evolution and suggests a shared driver gene status throughout disease progression. Clinical trial information: NCT02826564.

Randomized Phase 1 Trial of Pembrolizumab with Sequential Versus Concomitant Stereotactic Body Radiotherapy in Metastatic Urothelial Carcinoma

Preclinical data indicate that radiotherapy works synergistically with pembrolizumab, but the effect and toxicity of this combination may depend on radiotherapy timing. We conducted a randomized phase 1 trial combining pembrolizumab with either sequential (A) or concomitant (B) stereotactic body radiotherapy (SBRT) in metastatic urothelial carcinoma (mUC). No dose-limiting toxicity occurred. Treatment-related adverse events (trAEs; Common Terminology Criteria for Adverse Events v4.0) of grade 1-2 occurred in six of nine and all nine patients in arms A and B, respectively. One grade 3 trAE occurred in arm B. No grade 4-5 trAEs occurred. Overall response rates of 0% and 44.4% were noted in arms A and B, respectively, as per Response Evaluation Criteria in Solid Tumors v1.1. The trial was not powered to compare efficacy between arms. Targeted sequencing of tissue DNA and circulating tumor DNA (ctDNA) revealed high genomic concordance. Treatment response was associated with ctDNA fraction decline. We conclude that sequential and concomitant SBRT can be safely combined with pembrolizumab in mUC and that the effect of SBRT timing on efficacy is worth exploring further. PATIENT SUMMARY: This study assessed the safety of pembrolizumab combined with radiotherapy at two different time points in metastatic bladder cancer. We conclude that the combination treatment was well tolerated.

Dichotomous histopathological assessment of ductal carcinoma in situ of the breast results in substantial interobserver concordance

AIMS

Robust prognostic markers for ductal carcinoma in situ (DCIS) of the breast require high reproducibility and thus low interobserver variability. The aim of this study was to compare interobserver variability among 13 pathologists, in order to enable the identification of robust histopathological characteristics.

METHODS AND RESULTS

One representative haematoxylin and eosin-stained slide was selected for 153 DCIS cases. All pathologists independently assessed nuclear grade, intraductal calcifications, necrosis, solid growth, stromal changes, stromal inflammation, and apocrine differentiation. All characteristics were assessed categorically. Krippendorff's alpha was calculated to assess overall interobserver concordance. Cohen's kappa was calculated for every observer duo to further explore interobserver variability. The highest concordance was observed for necrosis, calcifications, and stromal inflammation. Assessment of solid growth, nuclear grade and stromal changes resulted in lower concordance. Poor concordance was observed for apocrine differentiation. Kappa values for each observer duo identified the 'ideal' cut-off for dichotomisation of multicategory variables. For instance, concordance was higher for 'non-high versus high' nuclear grade than for 'low versus non-low' nuclear grade. 'Absent/mild' versus 'moderate/extensive' stromal inflammation resulted in substantially higher concordance than other dichotomous cut-offs.

CONCLUSIONS

Dichotomous assessment of the histopathological features of DCIS resulted in moderate to substantial agreement among pathologists. Future studies on prognostic markers in DCIS should take into account this degree of interobserver variability to define cut-offs for categorically assessed histopathological features, as reproducibility is paramount for robust prognostic markers in daily clinical practice. A new prognostic index for DCIS might be considered, based on two-tier grading of histopathological features. Future research should explore the prognostic potential of such two-tier assessment.

A phase I/II trial of fixed-dose stereotactic body radiotherapy with sequential or concurrent pembrolizumab in metastatic urothelial carcinoma: evaluation of safety and clinical and immunologic response

Background

Current first-line standard of therapy for metastatic urothelial carcinoma is platinum-based combination chemotherapy. Pembrolizumab in phase III has demonstrated a promising overall response rate of 21.1% in patients with progression or recurrence after platinum-based chemotherapy. Preclinical and clinical evidence suggests that radiotherapy has a systemic anti-cancer immune effect and can increase the level of PD-L1 and tumor infiltrating lymphocytes in the tumor microenvironment. These findings gave rise to the hypothesis that the combination of radiotherapy with anti-PD1 treatment could lead to a synergistic effect, hereby enhancing response rates.

Methods

The phase I part will assess the dose limiting toxicity of the combination treatment of stereotactic body radiotherapy (SBRT) with four cycles of pembrolizumab (200 mg intravenously, every 3 weeks) in patients with metastatic urothelial carcinoma. The dose of both pembrolizumab and SBRT will be fixed, yet the patients will be randomized to receive SBRT either before the first cycle of pembrolizumab or before the third cycle of pembrolizumab. SBRT will be delivered (24 Gy in 3 fractions every other day) to the largest metastatic lesion. Secondary objectives include response rate according to RECIST v1.1 and immune related response criteria, progression-free survival and overall survival. The systemic immune effect triggered by the combination therapy will be monitored on various time points during the trial. The PD-L1/TIL status of the tumors will be analyzed via immunohistochemistry and response rates in the subgroups will be analyzed separately. A Simon’s two-stage optimum design is used to select the treatment arm associated with the best response rate and with acceptable toxicity to proceed to the phase II trial. In this phase, 13 additional patients will be accrued to receive study treatment.

Discussion

The progress made in the field of immunotherapy has lead to promising breakthroughs in various solid malignancies. Unfortunately, the majority of patients do not respond. The current trial will shed light on the toxicity and potential anti-tumor activity of the combination of radiotherapy with anti-PD1 treatment and may identify potential new markers for response and resistance to therapy. Trial registration this trial is registered on clinicaltrials.gov (NCT02826564).

Electronic supplementary material

The online version of this article (doi:10.1186/s12967-017-1251-3) contains supplementary material, which is available to authorized users.

[Pitfalls for renogram interpretation in pediatric urology]

Renograms are currently used for functional assessment by pediatric urologists. The aim of the present work was to focus on the potential pitfalls concerning renography. Potential confounding factors are described in reference to concrete cases. The main types of pitfalls concern venous or urinary catheters and background area definition. Protocols and renogram interpretation are critiqued in a bibliographic review. We propose a technical update and original data on the potential pitfalls in renography interpretation. Multidisciplinary discussion between nuclear medicine, pediatrics and pediatric surgery departments is required before drawing conclusions.

Unclassifiable B-cell lymphoma occurring after necrotizing pneumonia

We report a case of CD20+ grey zone lymphoma (GZL) with Reed Sternberg cells as an unexpected pathological diagnosis of a destroyed right lower lobe after necrotizing pneumonia. These GZLs show overlapping features of classical Hodgkin's lymphoma and diffuse large B-cell lymphoma. GZLs are a rare specific entity of lymphomas, and the aetiology is unknown. The diagnosis is confirmed by pathological, immunohistochemical and molecular analyses. The optimal treatment is unknown. The prognosis of these patients is poor.

An unusual tumour causing neonatal respiratory distress

PROBLEM

We present the case of a term neonate referred shortly after birth because of breathing and feeding difficulties.

METHODOLOGY

Fiber-endoscopic examination of the nasal cavity showed a pendulating mass in the nasopharynx.

RESULTS

A complete surgical resection was performed and the baby recovered completely. Microscopic examination of the mass showed an overlying non-keratinized squamous cell lining with an atypical cell population in some fragments. Histological features were compatible with a high-grade epithelial tumour like a midline carcinoma, but a final diagnosis of a salivary gland anlage tumour was established.

CONCLUSION

Flexible fiber endoscopy is the method of choice for examining the nasal passages and oropharynx in neonates with respiratory distress. Congenital salivary gland anlage tumour is a rare cause of neonatal nasal obstruction; it is benign and complete excision results in a cure. Histologically, it may mimic a malignant tumour owing to the high mitotic index.

Neoplastic meningitis: a rare presentation of bronchial adenocarcinoma

Following chronic daily headache, neoplastic meningitis was diagnosed in a non-smoking 44-year-old man. A bronchial adenocarcinoma was found to be the primary tumor. He was treated with erlotinib. Meningitis as the first manifestation of a malignancy is very rare.

Chemotherapy response evaluation in metastatic colorectal cancer with FDG PET/CT and CT scans

BACKGROUND

[18F]-fluorodeoxyglucose with positron-emission tomography (PET) and computed tomography (CT) scans were used to assess morphological and metabolic tumour response after chemotherapy in metastatic colorectal cancer.

PATIENTS AND METHODS

Twenty-five patients were evaluated after 4 courses of chemotherapy (+/-target therapy), and among them 20 patients after 2 courses. Response Evaluation Criteria In Solid Tumors (RECIST) and European Organisazion for Research and Treatment of Cancer (EORTC) criteria were used to evaluate CT and PET respectively.

RESULTS

Discrepancies between the two procedures were noted after 4 courses of chemotherapy in patient-based analysis. Two morphologically complete responses (CR) were correlated with metabolic response. Seven morphological partial responses (PR) were evaluated as 3 metabolic PR, 2 CR and 1 progressive disease (PD). Seventeen cases of morphologically stable disease (SD) were evaluated as 3 metabolic CR, 13 PR and 1 PD. These discrepancies were confirmed in lesion-based analysis. Perfect concordance was noted between metabolic responses obtained after 2 and 4 cycles.

CONCLUSION

Morphological and metabolic imaging does not permit concordant therapeutic assessment in metastatic colorectal cancer.

HCV Core Protein Augments Cyclosporine Immunosuppression

Hepatitis C viremia occurs universally after liver transplantation. It is speculated that soluble HCV proteins may be immunomodulatory. We measured the effects of HCV core upon human T-cell proliferation, expression of activation markers, and interaction with cyclosporine. Cells were activated with anti-CD3 for 2-6 days. Cultivation with 1, 2, 4, and 8 microg/mL core reduced tritiated thymidine uptake by 7% (P = ns), 63% (P < .001), 69% (P < .001) and 92% (P < .001). Direct cell counting (10(4)) showed proliferative inhibition in treated cultures after 2 days (84%, P < .05), 4 days (93%, P < .05), and 6 days (88%, P < .05). Viability remained greater than 90%. Expression of activation markers was reduced with core treatment. Treatment with 4 microg/mL core for 2, 4, and 6 days reduced CD2+CD25+ by 67% (P < .05), 67% (P < .05), and 51% (P < .05) and CD2+DR+ expression by 54% (P < .05), 46% (P < .05), and 54% (P < .05). Interaction between core and cyclosporine was determined by isobologram analysis which determines whether interactions are synergistic, additive or antagonistic. Combining core with cyclosporine resulted in an additive effect upon proliferative suppression. Linear regression confirmed an additive interaction with an r2 value of 0.98. The data shows that soluble core causes dose dependent suppression of T-cell proliferation and may potentiate suppression by cyclosporine.

Assessment of 18F-fluorodeoxyglucose dual-head gamma camera in asbestos lung diseases

The purpose of this study was to evaluate the performance of 18F-fluorodeoxyglucose (18FDG) imaging via coincidence detection emission tomography (CDET) in identifying malignant lesions in subjects exposed to asbestos. A total of 30 patients exposed to asbestos underwent 18FDG-CDET between January 2000 and June 2003. A CDET scan of the thorax and abdomen was performed 60 min after injection of 18FDG in fasting patients, and results were obtained in slices in three axes. The CDET results were compared to those from computed tomography (CT), and pleural or surgical biopsy in patients with positive 18FDG-CDET results. All primary malignant mesotheliomas accumulated 18FDG (n=6), and, in two patients, CDET findings were superior to those of CT, allowing early detection. In two cases, lung carcinomas with malignant pleural effusion were also detected. There were five false positive CDET results: three unilateral pleural thickening, one rounded atelectasis, and one benign lung nodule. All patients with pleural plaques showed no significant 18FDG uptake. Malignant diseases were detected by 18FDG-CDET imaging with a sensitivity of 89% and specificity of 71%. Coincidence detection emission tomography can identify malignant mesothelioma in selected subjects exposed to asbestos. Coincidence detection emission tomography appears to be a useful noninvasive method for the follow-up of subjects with exposure risk of asbestosis.

Comparison of 125I-interferon-alpha binding to peripheral blood cells from African-Americans and Caucasians with hepatitis C

Interferon-alpha (IFN-alpha) is the major treatment for chronic hepatitis C virus (HCV) infection. Drug resistance is problematic, particularly among African-Americans who typically show poorer clinical outcomes than Caucasians. The reasons for ethnic variation in IFN-alpha sensitivity are not clear. We speculated that African-American insensitivity to IFN-alpha may be mediated by reduced density of the IFN-alpha receptor (IFN-alphaR) or reduced internalization of the IFN-alpha/IFN-alphaR complex. This speculation was evaluated by comparing binding, uptake and release of 125iodine-labelled IFN-alpha (125I-IFN-alpha) to peripheral blood cells from African-Americans and Caucasians with HCV infection and ethnically matched healthy volunteers. Under various in vitro conditions, binding of 125IFN-alpha to surface receptors was equivalent (P = ns) between African-Americans and Caucasians with HCV infection as well as healthy volunteers (P = ns). Similarly, internalization and release of the 125I-IFN-alpha/IFN-alphaR complex was equivalent (P = ns) between African-Americans and Caucasians with HCV infection and healthy volunteers (P = ns). In addition, ethnicity did not influence (P = ns) IFN-alpha suppression of phytohaemagluttinen induced proliferation. However, IFN-alpha therapy of the same patients showed that African-Americans had lower response rates than Caucasians (14%vs 54%, P < 0.0001). In summary, IFN-alpha resistance among African-Americans is not mediated by intrinsic differences in IFN-alpha receptor density or internalization.

Basement membrane and connective tissue proteins in intestinal mucosa of patients with coeliac disease

AIMS

Gluten ingestion in coeliac disease is associated with alterations of the intestinal mucosa, especially the expansion of the lamina propria. Antiendomysium and antireticulin antibodies may result from interactions between gliadin and extracellular matrix components. By behaving as autoantigens, connective tissue proteins could initiate mucosal damage. This study evaluates changes in the distribution of laminin, type IV collagen, and fibronectin in the mucosa of patients with coeliac disease in an attempt to explain the alterations of mucosal morphology.

METHODS

Intestinal biopsies were obtained from patients with coeliac disease on admission and while on a gluten free diet. The distribution of type IV collagen, laminin, fibronectin, and alpha-smooth muscle actin was evaluated by immunofluorescence and by immunogold labelling and electron microscopy.

RESULTS

In patients with coeliac disease, the intensity of type IV collagen, laminin, and fibronectin immunofluorescent staining was decreased and less well defined than in controls, with frequent breaches in the basement membrane; fibronectin staining was weak in the distal third of the elongated crypts and absent under the flat surface. The distribution of smooth muscle fibre in the distal lamina propria of flat mucosae was altered. The distribution of these proteins was normal as assessed by immunoelectron microscopy.

CONCLUSIONS

The intensity of staining of some components of the basement membrane is decreased in coeliac disease and the distribution of smooth muscle fibres is altered. These changes may result from interactions between gliadin and components of the extracellular matrix and may play a role in the genesis of mucosal lesions and in the damage to the epithelium.

[The role of connective tissue in the morphology and function of intestinal mucosa. Its participation in the pathogenesis of celiac diseases]

The differentiation, architecture and function of the mucosa of the digestive tract is the result of close interactions between the epithelial cells and their underlying connective tissue. This interaction not only plays a role in the normal morphological organization of the intestinal mucosa but also in the organization and maturation of the enterocytes, the development of some of their enzymatic activities, the transport of nutrients and the restitution of the epithelium following denudation of the surface of villi due to loss of enterocytes. It is thought that disturbances of the cells of the connective tissue, especially of the myofibroblasts as well as of some of the above mentioned mechanisms, participate in the pathogenesis of some gastrointestinal diseases, celiac disease among them. This review summarizes some of the knowledge in this area.