Urothelial carcinoma of the bladder with seminal vesicle invasion: prognostic significance

Urothelial Carcinoma: Update on Staging and Reporting, and Pathologic Changes Following Neoadjuvant Chemotherapies

Staging and reporting of cancers of the urinary tract have undergone major changes in the past decade to meet the needs for improved patient management. Substantial progress has been made. There, however, remain issues that require further clarity, including the substaging of pT1 tumors, grading and reporting of tumors with grade heterogeneity, and following NAC. Multi-institutional collaborative studies with prospective data will further inform the accurate diagnosis, staging, and reporting of these tumors, and in conjunction with genomic data will ultimately contribute to precision and personalized patient management.

Staging of bladder cancer

Urothelial carcinoma of the urinary bladder is a heterogeneous disease with multiple possible treatment modalities and a wide spectrum of clinical outcome. Treatment decisions and prognostic expectations hinge on accurate and precise staging, and the recently published American Joint Committee on Cancer (AJCC) Staging Manual, 8th edition, should be the basis for staging of urinary bladder tumours. It is unfortunate that the International Union Against Cancer (UICC) 8th edition failed to incorporate new data which is considered in the AJCC 8th edition. Thus, the AJCC 8th edition is the focus of this review. Several critical changes and clarifications are made by the AJCC 8th edition relative to the 7th edition. Although the most obvious changes in the 8th edition are in the N (i.e. perivesical lymph node involvement now classified as N1) and M (i.e. M1 is subdivided into M1a and M1b) categories, several points are clarified in the T category (e.g. substaging of pT1 should be attempted). Further optimisation, however, is required. No particular method of substaging pT1 is formally recommended. In this review, these modifications are discussed, as well as points, which require further study and optimisation.

Contemporary Grading and Staging of Urothelial Neoplasms of the Urinary Bladder: New Concepts and Approaches to Challenging Scenarios

Grading and staging of urothelial neoplasm are the most crucial factors in risk stratification and management; both necessitate optimal accuracy and consistency. Several updates and recommendations have been provided though recent publications of the 4th edition of the World Health Organization classification, the 8th edition of the American Joint Committee on Cancer staging system, and the International Consultation on Urological Diseases-European Association of Urology updates on bladder cancer. Updates and recent studies have provided better insights into and approaches to the challenging scenarios in grading and staging of urothelial neoplasm; however, there remain aspects that need further investigation and refinement.

Challenges in Pathologic Staging of Bladder Cancer: Proposals for Fresh Approaches of Assessing Pathologic Stage in Light of Recent Studies and Observations Pertaining to Bladder Histoanatomic Variances

The paradigm of pathologic stage (pT) categorization in bladder cancer remains the depth of invasion into the different histologic layers of the bladder wall. However, the approaches to assigning pT stage category toward an enhanced outcome stratification have been marked by challenges and innovations, due in part to our growing appreciation of the surprisingly perplexing bladder histoanatomy. Upstaging of pT1 tumors after radical cystectomy is substantial and underscores the potential value of pT1 substaging in transurethral resection (TUR) specimens. The 2017 American Joint Committee on Cancer tumor-node-metastasis system recommends pT1 substaging but recognizes the need to optimize the approach. Over the years, the cut-off for microinvasion has been significantly lowered to 0.5 mm and is now a promising scheme for pT1 (micrometric) substaging. Unlike the micrometric approach, histoanatomic substaging using muscularis mucosae (MM) and vascular plexus as landmarks is less feasible in TUR specimens and inconsistent in stratifying the outcome of pT1 tumors. The lamina propria possesses inherent variations in depth, MM, and vascular plexus dispositions that should be factored in future pT1 substaging proposals. Histoanatomic variations among the bladder regions also occur, and studies suggest that trigone and bladder neck cancers may have more adverse outcomes. The muscularis propria (MP), besides being the essential histologic landmark for assigning pT2 stage category, is also considered a surrogate for the adequacy of TUR, furthering the importance of identifying its presence in TUR specimens. MP, however, may be mimicked by hyperplastic or isolated MP-like MM muscle bundles in the lamina propria with overstaging implications, and caution should be exercised in distinguishing these 2 muscle types morphologically and immunohistochemically. Presence of additional superficial MP unique from the detrusor muscle proper may also complicate staging at the trigone and ureter insertion sites. With regard to the depth of MP invasion, large and multicenter studies have reaffirmed the prognostic significance of pT2a/b subcategories. It is revealed that there are at least 3 ways used to demarcate the irregular MP to perivesical soft tissue junction, and use of a common criterion indicates improvement in pT2b/pT3a staging reproducibility. Although studies have shown significantly poorer outcome in pT3b compared with pT3a tumors, this designation has a substantial reliance on the prosector's gross assessment of perivesical soft tissue invasion which if performed incorrectly may lead to staging inaccuracy of pT3 tumors. The 8th edition of the American Joint Committee on Cancer has updated the staging schema for bladder cancers with concomitant prostatic stromal invasion and cancers within bladder diverticula. Because of 2 possible pT designations, prostatic stromal invasion in TUR specimens should not be automatically staged as either pT4a or pT2 (urethral). Recent data support that bladder cancer invading into the seminal vesicle has comparable outcome to pT4b tumors. Interestingly, several studies in pT4a tumors, which are staged based on sex-specific organs, have shown poorer outcome in females than males after radical cystectomy, and while there are possibly several reasons, they may also include anatomic factors. Despite the progress has been made, work remains to be done to inform future bladder cancer pT category definitions and their reproducibility in application and prognostication.

Concomitant seminal vesicle invasion in pT4a urothelial carcinoma of the bladder with contiguous prostatic infiltration is an adverse prognosticator for cancer-specific survival after radical cystectomy

PURPOSE

To evaluate the prognostic value of concomitant seminal vesicle invasion (cSVI) in patients with urothelial carcinoma of the bladder (UCB) and contiguous prostatic stromal infiltration in a large cystectomy series.

METHODS

A total of 385 patients with UCB and contiguous prostatic infiltration comprised our study. Patients were divided in two groups according to cSVI. Median follow-up was 36 months (interquartile range 11-74); the primary end point was cancer-specific mortality. The prognostic impact of cSVI was evaluated using multivariable Cox regression analysis. The predictive accuracy was assessed by a receiver operating characteristic analysis.

RESULTS

A total of 229 patients (59.5 %) without cSVI comprised group A, and 156 patients (40.5 %) with cSVI comprised group B. Positive lymph nodes (63 vs. 44 %, p < 0.001) and positive surgical margins (34 % vs. 14 %, p < 0.001) were more common in patients with cSVI. The 5- and 10-year cancer-specific survival rates were 41 % and 32 % (group A) and 21 and 17 % (group B) (p < 0.001). In multivariable analysis, pathological nodal stage (hazard ratio [HR] 2.19, p < 0.001), soft tissue surgical margin (HR 1.57, p = 0.010), clinical tumor stage (HR 1.46, p = 0.010), adjuvant chemotherapy (HR 0.40, p < 0.001), and cSVI (HR 1.69, p < 0.001) independently impacted cancer-specific mortality. The c-indices of the multivariable models with and without inclusion of cSVI were 0.658 (95 % confidence interval 0.60-0.71) and 0.635 (95 % confidence interval 0.58-0.69), respectively, resulting in a predictive accuracy gain of 2.3 % (p = 0.002).

CONCLUSIONS

In patients with UCB and prostatic stromal invasion, cSVI adversely affected cancer-specific survival compared to patients without cSVI. The inclusion of cSVI significantly improved the predictive accuracy of our multivariable model regarding survival.

Clinicopathologic characteristics and overall survival in patients with bladder cancer involving the gastrointestinal tract

Involvement of the gastrointestinal (GI) tract by bladder cancer is rare and documented in only a few case reports with no prognostic information available. The aim of this study was to clinicopathologically characterize patients with pathologically proven bladder cancer in the GI tract. We reviewed pathology reports from cystectomy patients at our institution from 2006 to 2011, identifying those with GI involvement at or after cystectomy. Overall survival (OS) was analyzed using Kaplan-Meier curves and Cox proportional hazard regression models. Twelve patients had surgical pathology specimens with GI involvement (anus, rectum, colon, and small bowel) at (n = 11) or within 4 months (n = 1) of cystectomy. These patients were noted to be pathologically staged inconsistently. GI involvement was a negative predictor of survival, with a 1.5-year OS of 25 versus 62 % without GI involvement (P < 0.001), similar to our pT4 patients (OS 26 %). In node-negative patients, there was a significantly worse 1.5-year OS with GI involvement compared to those without tumor in the GI tract (P = 0.005). We provide the first case series of patients with bladder cancer in the GI tract. GI involvement is a strong negative predictor of survival and behaves comparable to pT4 patients. However, we recommend that pathologists adhere to the current pT staging guidelines, in which GI involvement is not a criterion, until further research is conducted illustrating if and how it should be incorporated.