Routine urethroscopic surveillance is of limited value after radical cystectomy: a single centre retrospective cohort analysis

PURPOSE

The incidence of urethral recurrence (UR) following radical cystectomy (RC) for transitional cell carcinoma (TCC) of the bladder varies between 1.5 and 6%. There is debate over the timing of urethrectomy for patients undergoing RC. We evaluated the requirement for a formal surveillance programme for UR in patients after RC.

METHODS

We retrospectively reviewed the outcomes of patients who underwent RC between 2006 and 2019. Females, non-TCC cases and patients with neo-bladder diversions were excluded. Histological prostatic urethral involvement at the time of RC was deemed high risk for UR. Carcinoma in-situ, multifocal tumours and bladder neck involvement were deemed intermediate risk and the absence of the above features was considered low risk.

RESULTS

417 patients underwent RC, 300 cases remained after exclusion criteria were applied. 42 patients were high-risk for UR, 102 patients were intermediate risk and 156 were low risk. Of the 300, 24 urethrectomy cases were recorded. Six cases of UR occurred. Of these, 5 presented with symptoms and only 1 case was detected by surveillance. Only 1 low-risk patient developed UR, 7 years post RC. Using our risk stratification, UR rates for high, intermediate and low-risk cohorts were 25%, 10.5% and 0.8%, respectively.

CONCLUSIONS

In our cohort, routine surveillance for all patients with annual urethroscopy was of limited value in detecting UR post RC. Staged Urethrectomy for high and intermediate-risk patients, and patient counselling in self-identification of recurrence symptoms for low-risk patients will improve the early detection of UR.

Abstract 782: Exploring the contribution of introgressed ancient DNA to prostate cancer racial disparity

Introduction: Prostate cancer is the most common cancer in men and there is racial disparity in prostate cancer incidence and mortality globally, with greater disease burden in men of African ancestry, followed by European ancestry and least in men of Asian ancestry. The etiology of prostate cancer is not fully understood, but includes genetic and environmental factors. Present day non-Africans are reported to have introgressed DNA from Neanderthal and Denisovan ancestors. Over 170 prostate cancer associated single nucleotide polymorphisms (SNPs) have been identified from several genome-wide association studies (GWAS), with SNPS on chromosomes 2, 8 and 22 reported as showing variation between African and non-African men with prostate cancer. We performed analysis of prostate cancer associated SNPs on chromosomes 2, 8 and 22 to determine if DNA introgression could explain the racial variation.

Methods: We obtained data on prostate cancer associated SNPs from the GWAS catalog (https://www.ebi.ac.uk/gwas) and from reports that were not included in the catalog. Using an Ancient Genome Browser provided by the Max Plank Institute (https://www.eva.mpg.de/genetics/genomeprojects/neandertal/index.html), we determined whether SNPs on chromosomes 2, 8 and 22 were present in African, Neanderthal or Denisovan genomes. Based on the results, we inferred that SNPs were introgressed if they were present in Neanderthal or Denisovan genomes but absent from African genomes.

Results: 49, 59 and 17 prostate cancer SNPs were reported in chromosomes 2, 8 and 22 respectively. 23/49 in ch2, 25/59 in ch8 and 9/17 in ch22 were present in Neanderthal and or Denisovan genomes. SNPs in ch2 (rs13403657, rs12621278) and ch8 (rs7825414) were present in Neanderthal or Denisovan genomes but absent in African genomes. These SNPs lie in regions that have previously been reported to harbor introgressed DNA.

Conclusion: Our analyses identified prostate cancer associated SNPs that are likely to have been introgressed into present day non-Africans by extinct Neanderthal and Denisovan ancestors. Phenotypic changes caused by introgressed DNA could be contributing to racial disparities in prostate cancer in present day humans.

Citation Format: Evi O. Useh, Suresh Venugopal, Chidi N. Molokwu. Exploring the contribution of introgressed ancient DNA to prostate cancer racial disparity [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 782.

Abstract PO-192: Exploring the contribution of introgressed ancient DNA to prostate cancer racial disparity

Introduction Prostate cancer is the most common cancer in men and there is racial disparity in prostate cancer incidence and mortality globally, with greater disease burden in men of African ancestry, followed by European ancestry and least in men of Asian ancestry. The etiology of prostate cancer is not fully understood but includes genetic and environmental factors. Present day non-Africans are reported to have introgressed DNA from Neanderthal and Denisovan ancestors. Over 170 prostate cancer associated single nucleotide polymorphisms (SNPs) have been identified from several genome-wide association studies (GWAS), with SNPS on chromosomes 2, 8 and 22 reported as showing variation between African and non-African men with prostate cancer. We performed analysis of prostate cancer associated SNPs on chromosomes 2, 8 and 22 to determine if DNA introgression could explain the racial variation. Methods We obtained data on prostate cancer associated SNPs from the GWAS catalog (https://www.ebi.ac.uk/gwas) and from reports that were not included in the catalog. Using an Ancient Genome Browser provided by the Max Plank Institute (https://www.eva.mpg.de/genetics/genome-projects/neandertal/index.html), we determined whether SNPs on chromosomes 2, 8 and 22 were present in African, Neanderthal or Denisovan genomes. Based on the results, we inferred that SNPs were introgressed if they were present in Neanderthal or Denisovan genomes but absent from African genomes. Results 49, 59 and 17 prostate cancer SNPs were reported in chromosomes 2, 8 and 22 respectively. 23/49 in ch2, 25/59 in c 8 and 9/17 in ch22 were present in in Neanderthal and or Denisovan genomes. SNPs in ch2 (rs13403657, rs12621278) and ch8 (rs7825414) were present in Neanderthal or Denisovan genomes but absent in African genomes. These SNPs lie in regions that have previously been reported to harbour introgressd DNA. Conclusion Our analyses identified prostate cancer associated SNPs that are likely to have been introgressed into present day non-Africans by extinct Neanderthal and Denisovan ancestors. Phenotypic changes caused by introgressed DNA could be contributing to racial disparities in prostate cancer in present day humans.

Citation Format: Evi O. Useh, Suresh Venugopal, Chidi N. Molokwu. Exploring the contribution of introgressed ancient DNA to prostate cancer racial disparity [abstract]. In: Proceedings of the AACR Virtual Conference: Thirteenth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2020 Oct 2-4. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(12 Suppl):Abstract nr PO-192.

Abstract 2301: Indications for systematic prostate biopsy in men with negative multi-parametric magnetic resonance imaging

Introduction: Multiparametric Magnetic Resonance Imaging (mpMRI) is a valuable tool in the prostate cancer diagnostic pathway, and MRI-influenced biopsy has been shown to be superior to systematic biopsy alone for detecting clinically significant prostate cancer (csPCa), defined as the presence of any Gleason ≥ 4. Negative predictive value of mpMRI for csPCa varies widely in published reports, with a median of approximately 88%. Counselling patients with negative mpMRI (PIRADS score <3)to decide whether or not to proceed with systematic biopsy or PSA monitoring could be challenging. Several studies have shown that a PSA density (PSAD) ≥ 0.15 is an indication for systematic biopsy. We analysed the clinical, radiological and pathological features of patients with negative mpMRI but csPca on systematic biopsy to identify other criteria that may inform the need for systematic biopsy when mpMRI is negative.

Methods: For 18 months between Nov 2017 and May 2019, all men on our prostate diagnostic pathway with negative mpMRI were offered systematic biopsy. The criteria for pre-biopsy mpMRI was any man suitable for radical surgery or radiotherapy, plus one or more of PSA ≥ 3, palpable lesion on digital rectal examination, or family history of PCa in a first degree relative (father or brother). mpMRI was performed with a 1.5-Tesla magnet and included T2, DWI and DCE sequences. Systematic biopsy was TRUS-guided, with 8-16 biopsy cores.

Results: Of 589 mpMRI scans in 573 men, 216 (37%) had negative mpMRI. Of these, 141 (65%) proceeded with systematic biopsy. Among the men that had biopsy, Gleason 3+3 was detected in 12 men (9%) and Gleason ≥ 4 in six (4%). Important pre-biopsy features in men with Gleason ≥ 4 were PSAD ≥ 0.15 (n=3), artefact on MRI from hip joint prosthesis (n=1), and family history (n=2). There were no unusual histological variants seen on the positive biopsy cores.

Conclusion: Most men with negative mpMRI can avoid prostate biopsy and be managed with PSA monitoring. Based on our experience, we recommend systematic biopsy in men with negative mpMRI who have PSAD ≥ 1.5, family history or any imaging artifact that may alter image interpretation.

Citation Format: Chidi N. Molokwu, Christos Gkikas, Harry Bardgett, Nicola Lee, Faisal Ali, Rohit Chahal, Rajindra Singh. Indications for systematic prostate biopsy in men with negative multi-parametric magnetic resonance imaging [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 2301.

Multidisciplinary team management of patients with urological cancer

Several specialist teams are involved in the management of patients with urological cancer. These specialists have been brought together as a multidisciplinary team to discuss, plan and deliver care to patients in an effective, patient-centred approach. This article discusses the benefits of this approach and ways in which multidisciplinary team working can be optimized.

Abstract 3920: Tumor volume as a predictor of lymph node metastases in prostate cancer

Introduction: Pelvic lymph node dissection (PLND) is recommended during radical prostatectomy (RP) in patients with high risk prostate cancer (PCa). Guidelines recommend extended PLND in patients who have >5% probability of lymph node involvement, calculated from pre-operative parameters. PLND increases procedure time and potential morbidity to patients. Tumour size has been reported to be predictive of biochemical recurrence after RP. We analysed the utility of several parameters including tumour size in predicting lymph node metastases in order to further refine the population who require PLND during RP.

Materials & Methods: We maintained a prospective database of Robotic Assisted Radical Prostatectomy (RARP) from July 2012 to August 2016 consisting of a cohort of 531 patients. Patients with >5% calculated probability of lymph node metastasis had PLND during RARP. We performed multiple linear regression using age, PSA, D’Amico risk score, ISUP prognostic group, clinical T-stage, radiological T-stage, tumour volume, tumour volume relative to prostate size (relative tumour volume), and number of nodes excised during PLND to determine if any of these parameters could predict the presence of lymph node metastases.

Results: Of the cohort of 531 patients, 154 had PLND during RARP. Of the PLND cohort, 15 (10%) had pN1 disease. Tumour volume (r2 0.044, p= 0.0098), relative tumour volume (r2 0.033, p=0.026) and number of lymph nodes excised (r2 0.046, p=0.0075) were independent predictors of pN1 disease. D’Amico risk score (r2 0.019, p=0.089) approached but did not reach statistical significance. Patients with pN1 disease all had primary tumours ≥6cc.

Conclusions: In our cohort of PLND patients, tumour volume was an independent risk factor for pN1 disease. With the increasing availability of multi-parametric MRI, tumour volume can be measured pre-operatively as an adjunct to PIRADS scoring. The role of tumour volume and relative tumour volume in predicting lymph node metastasis in conjunction with other pre-operative parameters requires further investigation. The use of tumour volume in determining the need for PLND in patients undergoing RP may help to further refine the population at highest risk for pN1 disease and avoid the additional morbidity of PLND in those at low risk. In addition, our findings support the recommendation of performing an extended PLND to maximise regional lymph node clearance.

Citation Format: Chidi N. Molokwu, Keith Yuen, Sanjay Addla, Rajindra Singh, Rohit Chahal. Tumor volume as a predictor of lymph node metastases in prostate cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 3920. doi:10.1158/1538-7445.AM2017-3920

A novel technique for repair of testicular rupture after blunt trauma

OBJECTIVE

To present a simple technique for the repair of a ruptured testis after blunt trauma when extruded but viable testicular tissue prevents closure of the testicular capsule during surgical exploration. Preservation of viable testicular tissue is important because the risk of impaired fertility and hormone function is minimized.

METHODS

A 25-year-old male sustained a ruptured right testis confirmed by ultrasound. Testicular exploration was performed and hematoma evacuated. Extruded but viable testicular tissue was identified and preserved. The free edges of parietal tunica vaginalis was used to create a "neocapsule" around the testis and extruded tissue.

RESULTS

There were no postoperative complications. Follow-up Doppler ultrasound scan at 3 months showed a viable testis with no atrophic changes.

CONCLUSIONS

This technique avoids the loss of extruded but viable testicular tissue and may reduce the risk of impaired fertility and hormone function, without compromising the goals of scrotal exploration.

Outcomes of scrotal exploration for acute scrotal pain suspicious of testicular torsion: a consecutive case series of 173 patients

OBJECTIVE

• To determine the surgical outcome of all scrotal explorations performed on patients presenting with acute scrotal pain suspicious of testicular torsion.

PATIENTS AND METHODS

• Data was collected prospectively from a consecutive case series of patients of all ages who had scrotal exploration for acute testicular pain from 1998 to 2008. • The main outcome measures were pathology found during scrotal exploration, relationship between patient age and cause of scrotal pain, orchidectomy rate and the association between testicular torsion and cold weather.

RESULTS

• Data for 173 patients out of 179 was available for analysis. • The median age of the patients was 14 (0-92) years. 51% (n = 89) had testicular torsion, 24% (n = 42) had torsion of testicular appendages, 9% (n = 16) had epididymo-orchitis, and other pathology made up 5%. • No obvious pathology was seen in 10% (n = 17). • Patients with Torsion of Appendages were significantly younger than other patients with scrotal pain (P < 0.0001). • Age was not useful in discriminating between patients with Testicular Torsion from other patients with scrotal pain. 9% (n = 16) of all patients required an orchidectomy. • Frequency of Testicular Torsion was higher during the colder half of the year (n = 0.02).

CONCLUSIONS

• Testicular torsion was the most common finding at surgical exploration, followed by torsion of testicular appendages. • Age had limited value in diagnosing the cause of acute scrotal pain. • Testicular torsion was associated with cold weather. • Our findings support the practice of surgical exploration for acute scrotal pain suspicious of testicular torsion in patients of any age.

Androgen regulates ADAMTS15 gene expression in prostate cancer cells

Prostate cancer is a major cause of mortality, largely as a consequence of metastases and transformation to androgen-independent growth. Metalloproteinases are implicated in cancer progression. A disintegrin and metalloproteinase with thrombospondin motifs (ADAMTS) are expressed in prostate cancer cells, with ADAMTS-1 and ADAMTS-15 being the most abundant. ADAMTS-15 but not ADAMTS-1 expression was downregulated by androgen in LNCaP prostate cancer cells, possibly through androgen response elements associated with the gene. ADAMTS-15 expression is predictive for survival in breast cancer, and the situation may be similar in prostate cancer, as androgen independence is usually due to aberrant signaling through its receptor.

Biodeterioration potentials of fungal isolates from vegetable oils

The biodeterioration potentials of fungi isolated from vegetable oils were investigated. Growth of pure cultures of some mould species (Aspergillus flavus, Aspergillus niger, Aspergillus sp., Penicillium sp. and Fusarium sp.) and a mixed yeast culture (Saccharomyces sp., Candida sp. and Hansenula sp.) were monitored using six vegetable oils as substrates. Mould growth resulted in an increase in mycelial dry weight (g/100 ml) of the cultures in all the oils. Yeast growth in the oils caused decrease in pH, increase in optical density and increase in total viable count (TVC) in all the oils. Gas chromatographic analysis of the heptane extracts of the oils revealed that inoculated and uninoculated oil samples displayed similar chromatograms. Yeast growth in the oils also resulted in loss of some fatty acid components as well as biosyntheses of new ones.