Section 4 -

Reporting cancer containing bladder specimens Antonio Lopez-Beltran Cordoba University Medical School Cordoba, Spain

An appropriate assessment of the specimens and reporting of pathological findings may assist urologists in the appropriate management of these patients [1, 2, 3, 4]. The most common bladder specimens are obtained from endoscopic biopsies and transurethral resections of the bladder (TURB), both of which sample subepithelial tissue of varying depth. Other specimens can be obtained from a cystectomy (partial/total), cystoprostatectomy, pelvic exanteration ("En Block" resection), and resection of diverticula. Surgical excision of a urachal carcinoma usually includes the bladder dome, urachus, and umbilicus. The pathology report should include clinically relevant information as well as provide clinically useful information derived from the macroscopic examination and microscopic evaluation. Appropriated reporting of bladder cancer should include information related to: 1) specimen type, 2) tumor site and size, 3) histologic type, 4) associated epithelial lesions, 5) histologic grade, 6) tumor configuration, 7) adequacy of material for determining T category (TURB specimens), 8) pathologic staging (pTNM, 2002), and 9) additional pathologic findings (see appendix). Histologic Tumor Type More than 95% of carcinomas of the urinary bladder are urothelial. Focal squamous and/or glandular differentiation may be present in the tumor (mixed differentiation), aspect that must be clearly reported. Pure squamous or adenocarcinomas may also arise in the bladder, as well as other unusual histologic variants of urothelial carcinoma [1, 2]. Histologic Grade Due to the different classification systems available and the need for a universally acceptable system, the World Health Organization (WHO) and the International Society of Urological Pathology (ISUP) proposed in 1998 a consensus classification known as the WHO/ISUP classification. This, has recently been recognized as the WHO 2004 histological classification of non-invasive papillary urothelial tumors (low and high grade tumors). Until the WHO 2004 system is clinically and prognostically validated, tumor grade according to both the WHO 2004 system and the previous WHO (1973) system should be used. Urothelial (transitional cell) papilloma (World Health Organization [WHO] / International Society of Urologic Pathology [ISUP], 1998), urothelial (transitional cell) papilloma, inverted type; and papillary urothelial (transitional cell) neoplasm, low malignant potential (WHO/ISUP 1998) are included as associated epithelial lesions. Grading of adenocarcinoma and squamous cell carcinoma is based on the degree of differentiation, that is G1(well differentiated), G2 (moderately differentiated) and G3 (poorly differentiated). [1, 2, 3] Tumor growth pattern The pattern of growth is an important prognostic parameter in bladder cancer. This should be reported as papillary, solid/nodule, flat, ulcerated or indeterminate. The recent proposal of a morphologic classification distinguishing three patterns of growth (nodular, trabecular, and infiltrative type) needs to be validated. Tumors with an infiltrative growth pattern are associated with worse prognosis in comparison with tumor displaying a non-infiltrative growth pattern. Tumor extent The definition of the tumor extent requires knowledge of the components of the organ and its relationship with the adjacent structures. For instance, the urinary bladder consists of three layers: Epithelium and sub-epithelial connective tissue (or lamina propria) Muscularis mucosae (present in 94% of bladders) Muscularis propria (or detrusor muscle) The peri-vesical fat (peritoneum covering the superior surface and upper part) The bladder is located extraperitoneally. The TNM Staging System, 2002 revision, for carcinomas of the urinary bladder of the American Joint Committee on Cancer (AJCC)/International Union Against Cancer (UICC) is recommended. Stage T1 substaging based on the relationship of tumor with the muscularis mucosae is not universally accepted even though evidence seems to support its clinical value [1, 2, 3, 4, 5]. Tumor size and multicentricity The pathology report has to include the size of the tumor and information on its multicentricity. Margins Tumor involving the resection margin on pathologic examination may be assumed to correspond to residual tumor in the patient and may be classified as macroscopic or microscopic according to the findings at the specimen margin(s). The resection margins status should be carefully specified. In particular: Statements about deep soft tissue margins should specify whether peritoneal surfaces are involved by tumor. In cases of urachal adenocarcinoma in which partial cystectomy with excision of the urachal tract and umbilicus is performed, the margins of the urachal tract, i.e., the soft tissue surrounding the urachus and the skin around the umbilical margin, should be specified. Intraoperative frozen-section in bladder tumors is mainly used to assess surgical margin status both in partial specimens and radical cystectomy specimens but remains controversial. [4] Venous/Lymphatic Vascular Invasion Urothelial carcinoma may invade blood vessels or lymphatic channels. In suspicious cases, blood vessels can be highlighted by immunohistochemical staining for CD31 or CD34. This should be included in the report [3]. Urothelial carcinoma in situ (CIS) The evaluation of urothelium in patients who have superficial tumors is important because those patients who have associated CIS are at much higher risk of tumor recurrence and disease progression. [6] Additional information (immunohistochemical markers in the evaluation of bladder cancer) Several markers that characterize the appearance of a tumor have been considered to provide important information that may be predictive of disease recurrence. These include ki67-MIB1, CK20, or the expression of epidermal growth factor receptor or vascular endothelial growth factor in the surrounding tumor tissues. Markers that provide information concerning tumor progression include p53, pRb, p21Waf1, p27kip1, cadherins, bcl-2, and bax. Some of these are considered independent predictors while other are suggested adding to information provided by the histology of the specific lesion. Other markers have been proposed to provide information that may be predictive of response to treatment. These have included p53, pRb, p21Waf1, and MDR. Low E-cadherin expression and High DNA α-topoisomerasa II would identify invasive tumors with higher tendency to metastases and poor survival. However, information on markers predictive of therapy is limited mainly due to the need of strict standardization of methodology to make meaningful comparisons between different studies. Current evidence suggests that ki67-MIB1 may be the strongest candidate for a marker to predict recurrence and down-regulation of p27kip1 would be a marker of recurrence-free survival in high grade tumors, while p53 expression may be the strongest candidate to predict cancer progression, mainly in high grade urothelial carcinoma. [7, 8] Recent evidences suggest that G1-S modulators of the cell cycle such as Cyclin D1 and Cyclin D3 might be independent predictors of recurrence-free survival (Cyclin D1) and of stage progression-free and overall survival in stages TaT1 bladder cancer. [7, 8, 9] Concerning markers that may predict chemosensitivity, p53 might play a central role in susceptibility of bladder tumors against chemotherapy, since it has been postulated that p53 altered tumors are less able to initiate apoptosis and therefore resistant to chemotherapy treatment. Clinical data support this view. Obviously, these mechanisms need further intense investigation. Multidrug resistant genes (MDR) and its associated proteins represent another interesting group of markers of bladder tumors chemosensitivity but remain controversial. The presence of P-glycoprotein before chemotherapy did not predict the clinical outcome in patients with bladder cancer in some studies. The results suggest that intrinsic drug resistance in bladder cancer may be mediated primarily through P-glycoprotein; whereas acquired drug resistance may be associated with the combination of MDR associated protein and P-glycoprotein. Other immunohistochemical markers such Uroplakin III could be useful in establishing urothelial origin of a metastatic neoplasm. Cytoplasmic expression of Beta-catenin would indicate primary bladder adenocarcinoma since 81% of colorectal adenocarcinoma involving the bladder show nuclear staining. References Amin MB, Srigley JR, Grignon D, Reuter VR, Humphrey P, Cohen MB, Hammond MEH: For the members of the cancer committee, College of American Pathologists. Urinary Bladder, Ureter, and Renal Pelvis. Protocol Applies to all carcinomas of the urinary bladder, ureter, and renal pelvis, CAP approved, January 2005; available at: http://www.cap.org/apps/docs/cancer_protocols/2005/urbladder05_pw.pdf Lopez-Beltran A, Bassi P, Pavone-Macaluso M, Montironi R. Handling and pathology reporting of specimens with carcinoma of the urinary bladder, ureter, and renal pelvis. Eur Urol. 2004;45(3):257-66. Lapham RL, Grignon D, Ro JY. Pathologic prognostic parameters in bladder urothelial biopsy, transurethral resection, and cystectomy specimens. Sem Diagn Pathol 1997, 14:109-122 Algaba F, Arce Y, Lopez-Beltran A, Montironi R, Mikuz G, Bono AV. Intraoperative frozen section diagnosis in urological oncology. Eur Urol. 2005 ;47(2):129-36. Lopez-Beltran A, Cheng L. Stage pT1 bladder carcinoma: diagnostic criteria, pitfalls and prognostic significance. Pathology. 2003; 35:484-91. Lopez-Beltran A, Cheng L, Andersson L, et al. Preneoplastic non-papillary lesions and conditions of the urinary bladder :an update based on the Ancona international consultation. Virchows Arch 2002, 440:3-11 Lopez-Beltran A, Requena MJ, Luque RJ, Alvarez-Kindelan J, Quintero A, Blanca AM, Rodriguez ME, Siendones E, Montironi R. Cyclin D3 expression in primary Ta/T1 bladder cancer. J Pathol. 2006;209(1):106-13 Quintero A, Alvarez-Kindelan J, Luque RJ, Gonzalez-Campora R, Requena MJ, Montironi R and Lopez-Beltran A. Ki-67 MIB1 labelling index and the prognosis of primary TaT1 urothelial cell carcinoma of the bladder. J Clin Pathol. 2006 ;59(1):83-8 Lopez-Beltran A, Luque RJ, Alvarez-Kindelan J, Quintero A, Merlo F, Requena MJ, Montironi R. Prognostic factors in survival of patients with stage Ta and T1 bladder urothelial tumors: the role of G1-S modulators (p53, p21Waf1, p27Kip1, cyclin D1, and cyclin D3), proliferation index, and clinicopathologic parameters. Am J Clin Pathol. 2004;122(3):444-52