Spatial omics techniques and data analysis for cancer immunotherapy applications.

In-depth profiling of cancer cells/tissues is expanding our understanding of the genomic, epigenomic, transcriptomic, and proteomic landscape of cancer. However, the complexity of the cancer microenvironment, particularly its immune regulation, has made it difficult to exploit the potential of cancer immunotherapy. High-throughput spatial omics technologies and analysis pipelines have emerged as powerful tools for tackling this challenge. As a result, a potential revolution in cancer diagnosis, prognosis, and treatment is on the horizon. In this review, we discuss the technological advances in spatial profiling of cancer around and beyond the central dogma to harness the full benefits of immunotherapy. We also discuss the promise and challenges of spatial data analysis and interpretation and provide an outlook for the future.

Surveillance one year post focal cryotherapy for clinically significant prostate cancer using mpMRI and PIRADS v2.1: An initial experience from a prospective phase II mandatory biopsy study.

Objectives: Multiparametric magnetic resonance imaging (mpMRI) surveillance post focal cryotherapy (FT) of prostate cancer is challenging as post treatment artefacts alter mpMRI findings. In this initial experience, we assessed diagnostic performance of mpMRI in detecting clinically significant prostate cancer (csPCa) after FT. Materials and methods: This single-centre phase II prospective clinical trial recruited 28 men with localized csPCa for FT between October 2019 and April 2021. 12-months post FT mpMRI were performed prior to biopsy and sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of all mpMRI positive subjects were analysed. Chi square goodness of fit test correlated biopsy positive PIRADS3 (P3) and PIRADS4/5 lesions with histology grade group. One way ANOVA test assessed performance of ADC values in differentiating csPCa, non csPCa and benign lesions. Results: Sensitivity, specificity, PPV and NPV of mpMRI were 100%, 14.28%, 53.84% and 100% for subjects with histologically proven cancer. Correlation of PIRADS v2.1 scores with histologically proven prostate cancer was statistically significant (p < 0.5). Correlation of P3 lesions with non-csPCa was statistically significant (p < 0.02535). Higher ADC value was associated with benign histology (adjusted odds ratio OR 0.97, 95% confidence interval: 0.94, 0.99) (p = 0.008). Among the malignant lesions, higher ADC value was associated with non-csPCa (adjusted OR: 0.97; 95% CI: 0.95, 0.99) (p = 0.032). Conclusion: mpMRI is highly sensitive in detecting residual cancer. ADC values and PIRADS scores may be of value in differentiating csPCa from non-csPCa with a potential for risk stratification of men requiring re-biopsy versus non-invasive surveillance of remnant prostate.

Intensive sampling of the umbra and penumbra improves clinically significant prostate cancer detection and reduces risk of grade group upgrading at radical prostatectomy.

PURPOSE: Our objective is to evaluate the clinically significant prostate cancer detection rate of overlapping and perilesional systematic biopsy cores and its impact on grade group (GG) concordance at prostatectomy. MATERIALS AND METHODS: Biopsy maps of those undergoing MRI-targeted (TB) and systematic biopsy (SB) were reviewed to reclassify systematic cores. Perilesional (PL) cores were defined as adjacent cores within 10 mm of the target lesion ("penumbra") whilst overlap (OL) cores were defined as cores within the ROI itself ("umbra"). All other cores were designated as distant cores (DC). The incremental csPCa detection rate (GG ≥ 2) and the rate of GG upgrading on prostatectomy as OL, PL and DC sequentially added to TB were determined. RESULTS: Out of the 398 patients included, the median number of OL and PL cores was 5 (IQR 4-7) and 5 (IQR 3-6) respectively. OL cores detected more csPCa than PL cores (31 vs 16%, p < 0.001). OL and PL cores improved the csPCa detection rate of TB from 34 to 39% (p < 0.001) and 37% (p = 0.001) respectively. TB+OL+PL had greater csPCa detection compared to just TB+OL (41 vs 39%, p = 0.016) and TB+PL (41 vs 37%, p < 0.001). Of the 104 patients who underwent prostatectomy, GG upgrading rate for TB+OL+PL was lower compared to TB (21 vs 36%, p < 0.001) and was not significantly different compared to TB+OL+PL+DC (21 vs 19%, p = 0.500). CONCLUSION: A biopsy strategy incorporating both intensive sampling of the umbra and penumbra improved csPCa detection and reduced risk of GG upgrading at prostatectomy.

The role of magnetic resonance tumour regression grade in the prediction of regression and survival of rectal adenocarcinoma after long-course chemoradiotherapy: a cohort study.

Rectal cancer response to neoadjuvant long-course chemoradiotherapy (LCCRT) is assessed by magnetic resonance tumour regression grade (mrTRG) and this has an impact on surgical management. However, there is limited data on the correlation between mrTRG and pathological tumour regression grade (pTRG). This study aims to evaluate the correlation between mrTRG and pTRG and the prognostic value of mrTRG on survival. Methods: Between 2011 and 2016, patients with rectal cancer who underwent LCCRT and had post-LCCRT MRI were included in the study. Both mrTRG and pTRG were dichotomised into good responders (mrTRG 1-3 and pTRG 0-1) and poor responders (mrTRG 4-5 and pTRG 2-3). Correlation between mrTRG and pTRG was assessed with Cohen κ analysis. Survival analysis was performed with Kaplan-Meier test and Cox proportional hazard models. Results: There were 59 patients included in this study. There were significant reductions in anal sphincter and circumferential resection margin involvement in post-LCCRT MRI. Fair agreement was found between mrTRG and pTRG (κ=0.345). Sensitivity, specificity and accuracy of mrTRG 1-3 to predict good pathological response were 100%, 46.3% and 62.7%, respectively. On survival analysis, mrTRG 1-3 was not associated with improved overall survival and recurrence-free survival. Conclusions: While there is fair agreement in correlation between mrTRG and pTRG, MRI remains an objective, noninvasive assessment of tumour response. Further studies are required to improve the ability of mrTRG to predict good responders to LCCRT and evaluate its role as a prognostic marker for survival.

An approach to genetic testing in patients with metastatic castration-resistant prostate cancer in Singapore.

Introduction: There has been a rapid evolution in the treatment strategies for metastatic castration-resistant prostate cancer (mCRPC) following the identification of targetable mutations, making genetic testing essential for patient selection. Although several international guidelines recommend genetic testing for patients with mCRPC, there is a lack of locally endorsed clinical practice guidelines in Singapore. Method: A multidisciplinary specialist panel with representation from medical and radiation oncology, urology, pathology, interventional radiology, and medical genetics discussed the challenges associated with patient selection, genetic counselling and sample processing in mCRPC. Results: A clinical model for incorporating genetic testing into routine clinical practice in Singapore was formulated. Tumour testing with an assay that is able to detect both somatic and germline mutations should be utilised. The panel also recommended the "mainstreaming" approach for genetic counselling in which pre-test counselling is conducted by the managing clinician and post-test discussion with a genetic counsellor, to alleviate the bottlenecks at genetic counselling stage in Singapore. The need for training of clinicians to provide pre-test genetic counselling and educating the laboratory personnel for appropriate sample processing that facilitates downstream genetic testing was recognised. Molecular tumour boards and multidisciplinary discussions are recommended to guide therapeutic decisions in mCRPC. The panel also highlighted the issue of reimbursement for genetic testing to reduce patient-borne costs and increase the reach of genetic testing among this patient population. Conclusion: This article aims to provide strategic and implementable recommendations to overcome the challenges in genetic testing for patients with mCRPC in Singapore.

Clinicopathological features of non-conventional renal cell carcinoma histological subtypes: Learning points from a large contemporary series spanning over three decades.

PURPOSE: To perform a retrospective review of the clinicopathological features of patients with conventional and non-conventional renal cell carcinoma (cRCC and ncRCC). MATERIALS AND METHODS: A large prospectively maintained uro-oncological registry was accessed to extract clinicopathological data of patients diagnosed with renal tumors who subsequently underwent nephrectomy from 1990-2019. Demographics and operative parameters were extracted. Analyses of overall survival (OS) and cancer-specific survival (CSS) were performed using the Kaplan-Meier method. Cox proportional-hazards analysis was used to identify risk factors which influenced survival. RESULTS: There were a total of 1,686 consecutive nephrectomies which was retrieved, with 1,286 cRCC and 400 ncRCC. The commonest ncRCC subtypes were papillary (n=198, 11.7%), clear cell papillary (n=50, 3.0%) and chromophobe (n=49, 2.9%) RCC. Kaplan-Meier estimates of OS were higher in cRCC (0.74; 95% confidence interval [CI], 0.71-0.78) than ncRCC (hazard ratio, 1.47; 95% CI, 1.16-1.87). Among individual subtypes, chromophobe RCC had the highest 5-year OS (0.90; 95% CI, 0.79-1.0). Among ncRCC subtypes, acquired cystic RCC demonstrated the highest association with end-stage renal failure and hypertension, with the highest CSS. MiT family translocation RCC had the youngest mean age at presentation (45.6±12.8 y) and excellent CSS. Factors associated with increased OS in the entire cohort included shorter operative time, partial nephrectomy and lower tumor stages. CONCLUSIONS: This study provides a comprehensive contemporary overview of ncRCCs which are yet poorly characterized, in comparison to cRCCs. Data from this study would contribute towards tailored patient counseling and healthcare resource planning.

Priapism mimic: penile metastasis from hepatocellular carcinoma.

We describe the case of a metastatic penile tumour of hepatocellular origin treated with surgical resection.

Reducing the number of systematic biopsy cores in the era of MRI targeted biopsy-implications on clinically-significant prostate cancer detection and relevance to focal therapy planning.

BACKGROUND: The optimal number of systematic biopsy cores in the era of multi-parametric MRI targeted biopsy remains unclear, especially on its impact of focal therapy planning. Our objective is to investigate the impact of reducing the number of systematic cores on prostate cancer detection in the era of MRI-US fusion targeted biopsy and as well as its relevance in template planning for focal therapy. MATERIALS AND METHODS: A retrospective analysis of 398 consecutive men who underwent both systematic saturation (~24 cores) and MRI-US fusion targeted biopsy was performed. Four reduced-core systematic biopsy strategies (two-thirds, half, one-third and one-quarter systematic cores) were modelled and the detection rates of clinically-significant prostate cancer (csPCa defined as grade group ≥2) were compared to that of a full systematic biopsy using McNemar's test. Focal therapy treatment plans were made based on positive cores on combined (targeted and systematic) biopsy and the various reduced-cores strategies to compare the proportion who had a change in treatment plan. RESULTS: csPCa was detected in 42% (168/398) of this patient cohort. Non-targeted systematic saturation biopsy had a 21% (83/398) csPCa detection rate. Our four strategies reduced the mean number of non-targeted systematic cores from 21.8 to 14.5, 10.9, 7.3 and 5.4 cores and their csPCa detection rates were significantly decreased to 16%, 13%, 9% and 8% respectively (all p < 0.05). Compared to the reduced-core strategies, a full systematic saturation biopsy resulted in change to the focal therapy treatment plan in 12% (2/3 cores), 19% (1/2 cores), 24% (1/3 cores) and 29% (1/4 cores) of the time (p = 0.0434). CONCLUSIONS: Reducing the number of systematic biopsies when performing an MRI-targeted biopsy leads to reduced detection of csPCa and alter the treatment plans for focal therapy, possibly limiting its oncological efficacy.

NEAR trial: A single-arm phase II trial of neoadjuvant apalutamide monotherapy and radical prostatectomy in intermediate- and high-risk prostate cancer.

OBJECTIVE: Treatment efficacy of androgen deprivation therapy with radical prostatectomy for intermediate- to high-risk prostate cancer is less well-studied. The NEAR trial is a single-arm, phase II investigation of neoadjuvant apalutamide monotherapy and radical prostatectomy (RP) in the treatment of D'Amico intermediate- and high-risk prostate cancer (NCT03124433). MATERIALS AND METHODS: Patients with histologically-proven, D'Amico intermediate- to high-risk prostate adenocarcinoma received apalutamide 240 mg once-daily for 12 weeks followed by RP + /-lymphadenectomy. Primary outcome was pathological complete response (pCR) rate. Secondary outcomes included rate of biochemical response (defined by PSA < 0.03 ng/mL at week 24 from starting apalutamide without subsequent PSA relapse), treatment-related adverse events, and RP complication rates. Correlative biomarker analyses were performed to examine for molecular predictors of treatment responses. RESULTS: From 2017 to 2019, 30 patients were recruited, of which 20 and 10 were high and intermediate risk, respectively; 25 completed treatment as per-protocol. We did not observe any pCR on trial; median reduction of cancer burden was 41.7% (IQR: 33.3%-60.0%). 18 out of 25 patients were classified as having a biochemical response (4 did not achieve PSA of <0.03 ng/mL at week 24 and 3 developed PSA relapse subsequently). Dry skin (N = 16; 53.3%), fatigue (N = 10; 33.3%) and skin rash (N = 9; 30.0%) were the most common adverse events, and there was no major peri-operative complication. We observed an association between tumours of low androgen receptor activity and PAM50 basal status with biochemical non-responders, albeit these molecular phenotypes were not associated with pathological response. CONCLUSIONS: A 12-week course of neoadjuvant apalutamide prior to RP did not meet the primary endpoint of pCR in this trial. Tumours with low androgen receptor activity or of the PAM50 basal subtype may have a reduced response to apalutamide.

Cytomegalovirus-associated pseudomembranous colitis in a kidney transplant recipient.

Pseudomembranous colitis (PMC) is classically associated with Clostridium difficile infection. We report a rare case of cytomegalovirus (CMV)-associated PMC in a 52-year-old female patient who had undergone kidney transplantation more than 20 years ago and was on low dose prednisolone and ciclosporin. She presented with an acute history of fever, lethargy, vomiting and diarrhoea on admission. Computed tomography of the abdomen showed extensive colitis, and colonoscopy revealed extensive pseudomembrane formation. Multiple tests for Clostridium difficile and other common microbiological causes of colitis were negative. CMV DNAemia and colonic biopsies confirmed the diagnosis of CMV colitis. The patient responded to prompt CMV treatment, as demonstrated by clinical, endoscopic, and histological response. While CMV is a common pathogen in the solid organ transplant population that is familiar to most transplant physicians, it may present atypically as PMC. Here, we review the literature on CMV-associated PMC and its relevance to solid organ transplant recipients. To our knowledge, this is the first reported case of CMV-associated PMC in a kidney transplant recipient.

Defining prostate cancer size and treatment margin for focal therapy: does intralesional heterogeneity impact the performance of multiparametric MRI?

OBJECTIVES: To evaluate the impact of intralesional heterogeneity on the performance of multiparametric magnetic resonance imaging (mpMRI) in determining cancer extent and treatment margins for focal therapy (FT) of prostate cancer. PATIENTS AND METHODS: We identified men who underwent primary radical prostatectomy for organ- confined prostate cancer over a 3-year period. Cancer foci on whole-mount histology were marked out, coding low-grade (LG; Gleason 3) and high-grade (HG; Gleason 4-5) components separately. Measurements of entire tumours were grouped according to intralesional proportion of HG cancer: 0%, <50% and ≥50%; the readings were corrected for specimen shrinkage and correlated with matching lesions on mpMRI. Separate measurements were also taken of HG cancer components only, and correlated against entire lesions on mpMRI. Size discrepancies were used to derive the optimal tumour size and treatment margins for FT. RESULTS: There were 122 MRI-detected cancer lesions in 70 men. The mean linear specimen shrinkage was 8.4%. The overall correlation between histology and MRI dimensions was r = 0.79 (P < 0.001). Size correlation was superior for tumours with high burden (≥50%) compared to low burden (<50%) of HG cancer (r = 0.84 vs r = 0.63; P = 0.007). Size underestimation by mpMRI was more likely for larger tumours (51% for >12 mm vs 26% for ≤12 mm) and those containing HG cancer (44%, vs 20% for LG only). Size discrepancy analysis suggests an optimal tumour size of ≤12 mm and treatment margins of 5-6 mm for FT. For tumours ≤12 mm in diameter, applying 5- and 6-mm treatment margins would achieve 98.6% and 100% complete tumour ablation, respectively. For tumours of all sizes, using the same margins would ablate >95% of the HG cancer components. CONCLUSIONS: Multiparametric MRI performance in estimating prostate cancer size, and consequently the treatment margin for FT, is impacted by tumour size and the intralesional heterogeneity of cancer grades.

Prostatic ductal adenocarcinoma variant predicts worse pathological and oncological outcomes: Insight from over 1000 consecutive patients from a large prospective uro-oncology registry.

OBJECTIVE: To evaluate if prostatic ductal adenocarcinoma (PDA) independently predicts poorer pathological and oncological outcomes after radical prostatectomy (RP). METHODS AND MATERIALS: Utilizing a large prospective uro-oncology registry, clinicopathological parameters of 1027 consecutive patients who underwent RP (2008-2017) were recorded. Oncological outcomes were determined by failure to achieve unrecordable PSA postoperatively and biochemical failure (BCF). RESULTS: PDA was present in 79 (7.7%) patients, whereas 948 (92.3%) patients had conventional prostatic acinar adenocarcinoma (PAA). Patients with PDA were older (mean 64.4 vs. 62.8-years old; p = .045), had higher PSA at diagnosis (mean 12.53 vs. 10.80 ng/ml; p = .034), and a higher percentage of positive biopsy cores (mean 39.34 vs. 30.53%; p = .006). Compared to PAA, PDA exhibited a more aggressive tumor biology: (1) Grade groups 4 or 5 (26.6 vs. 9.4%, p < .001), (2) tumor multifocality (89.9 vs. 83.6%; p = .049), and (3) tumor size (mean 2.97 vs. 2.00 cm; p < .001). On multivariate analysis, PDA was independently associated with locally advanced disease (p = .002, hazard ratio [HR]: 2.786, 95% confidence interval [CI]: 1.473-5.263), with a trend towards positive surgical margins (p = .055) and nodal involvement (p = .061). Translating the poorer pathological features to oncological outcomes, presence of PDA independently predicted less likelihood of achieving unrecordable PSA (p = .019, HR: 2.368, 95% CI: 1.152-4.868, and higher BCF (p = .028, HR: 1.918, 95% CI: 1.074-3.423). Subgroup analysis demonstrated that a higher ductal component greater than 15% proportionally predicted worse oncological outcomes, with a shorter time to BCF of 14.3 months compared to 19.8 months in patients with ductal component lesser than 15% (p = .040, HR: 2.660, 95% CI: 1.046-6.757). CONCLUSION: PDA is independently associated with adverse pathological and oncological outcomes after RP. A higher proportion of PDA supports a higher BCF rate with a shorter time interval. An aggressive extirpative approach with close monitoring of postoperative serum PSA levels is warranted for these patients.

The optimal management of variant histology in muscle invasive bladder cancer.

Bladder cancer is a heterogenous disease that is associated with tangible mortality in muscle invasive disease. The WHO 2016 classification of urothelial tumours reflects the contemporary approach towards histological variants in bladder cancer, including variants of urothelial carcinoma (UC) and non-urothelial variants. This review focuses on variant histology in UC, and discusses the importance of accurate histological diagnosis, and subsequent risk stratification and therapeutic decision making based on proper variant recognition. Most urothelial variants are associated with poorer outcomes compared to conventional UC, although some perform reasonably better. However, high quality evidence detailing optimal treatment and survival outcomes are still lacking in literature, due to the rarity of these cases.

Tumour-to-tumour metastases: prostate carcinoma metastasising to a renal oncocytoma.

This is a case report of prostate carcinoma metastasising to a renal oncocytoma. The report demonstrates the unusual presentation of metastases from a common cancer to a common benign tumour, and reviews the rare phenomenon of tumour-to-tumour metastases.

Meta-analysis: sacral nerve stimulation versus conservative therapy in the treatment of faecal incontinence.

AIM: Sacral nerve stimulation (SNS) has recently been used in the management of faecal incontinence (FI). This study compared SNS to conservative management with regards to functional and quality of life outcomes. METHODS: Meta-analysis of studies published between 1995 and 2008 on SNS for FI was performed. Outcomes evaluated were functional, physiological and quality of life. A random-effects model was used and sensitivity analyses performed. Subgroup analyses were performed on age and sphincter status. RESULTS: Thirty-four studies were included, reporting on 944 patients undergoing peripheral nerve evaluation; 665 underwent permanent SNS. Weekly incontinence episodes (weighted mean difference [WMD] -6.83; 95% confidence intervals [CI] -8.05, -5.60; p < 0.001) and incontinence scores (WMD -10.57; 95% CI -11.89, -9.24; p < 0.001) were significantly reduced with SNS; ability to defer defecation (WMD 7.99 min; 95% CI 5.93, 10.05; p < 0.001) was increased. Most SF-36 and FIQL domains improved following SNS, and mean anal pressures increased significantly (p < 0.001). Results remained consistent on sensitivity analysis. The under-56 years age group showed smaller functional but greater physiological and quality of life improvements. Results were similar between sphincter intact and impaired subgroups. The complication rate was 15% for permanent SNS, with 3% resulting in permanent explantation. CONCLUSION: SNS results in significant improvements in objective and subjective measures for faecally incontinent patients.

Differential expression of p53 and p504s in hyperplastic polyp, sessile serrated adenoma and traditional serrated adenoma.

AIMS: Known collectively as serrated polyps, hyperplastic polyps (HP), sessile serrated adenomas (SSA/SSP) and traditional serrated adenoma (TSA) may represent a spectrum of increasing malignant potential with characteristic immunological markers. There is increasing evidence that HP, SSA/SSP and TSA are biologically different and are likely to represent a spectrum along the serrated polyp pathway. Although there is general consensus about the diagnostic features of serrated polyps, the morphological differences between the categories are often subtle. This study compares the expression of p53 and P504S among serrated polyps. Sixty seven randomly selected biopsies (n = 59) and resection specimens (n = 8) histologically diagnosed for SSA/SSP, TSA and HP (19, 30 and 18 specimens, respectively) were obtained. METHODS AND RESULTS: There was a significant difference in p53 (P < 0.001) and P504S (P < 0.001) immunopositivity and distribution among the serrated polyps. In particular, there is diffuse expression p53 and P504S in TSA compared to HP and SSA/SSP where p53 and P504S expression was more frequently confined to the lower 1/3 of the crypts. In addition, percentage of cells expressing p53 and p504S expression was higher in TSA than those of HP and SSA/SSP. CONCLUSION: Immunostains, p53 and P504S, may be useful adjuncts to morphological diagnosis of serrated polyps.

Bone marrow trephine morphology and immunohistochemical findings in chronic myelomonocytic leukaemia.

Chronic myelomonocytic leukaemia (CMML) is a clonal disorder with myelodysplastic/myeloproliferative features. Its diagnosis is based on the presence of peripheral blood monocytosis and bone marrow aspirate findings, according to World Health Organization criteria. However, bone marrow trephine biopsy (BMTB) features characteristic of CMML have not been adequately investigated. We studied BMTB in 20 cases of CMML-1 and three cases of CMML-2 and compared with ten cases of polycythaemia vera, ten cases of chronic myeloid leukaemia (chronic phase) and ten cases of florid myeloid hyperplasia (MH). Furthermore, we evaluated the use of CD34, CD117 and CD68 (PGM-1) antibodies in diagnosis and subtyping of CMML and in differentiating from other categories. Hypercellularity, high myeloid:erythroid ratio, increased proportion of 'myelo/monocytic' cells often seen as clusters and/or nodules, absence of eosinophilia, and presence of abnormal localisation of immature precursors (ALIP) and dysmegakaryopoiesis can aid in the diagnosis of CMML in BMTB. CD68 (PGM-1) positive cells amounted to 20.7 +/- 6.1% cells among CMML trephines. The proportion of CD34(+) cells among cases of CMML-1 was /=10% cells in two of three cases and 5% in the other case. Morphological and immunohistochemical features of BMTB samples are extremely helpful in the diagnosis of CMML.