The usefulness of the level of the muscularis mucosae in the staging of invasive transitional cell carcinoma of the urinary bladder

Abstract

The initial biopsy specimens from 50 patients with high-grade invasive transitional cell carcinoma of the urinary bladder were evaluated for depth of invasion. Stages were assigned according to the following system: T1A, invasion of connective tissue superficial to the level of the muscularis mucosae; T1B, invasion to the level of the muscularis mucosae; T1C, invasion through the level of the muscularis mucosae but superficial to the muscularis propria; and B, invasion into the muscularis propria. Follow-up from the Yale Tumor Registry at a median time of 4.6 years showed that tumors invasive to levels T1A and T1B had a 75% 5-year survival, but tumors invasive through the level of the muscularis mucosae but apparently superficial to the muscularis propria (level T1C) had an 11% 5-year survival, which was comparable with the survival of patients with tumors invasive of the muscularis propria. This study suggests the prognostic importance of assessing the depth of invasion in initial biopsy specimens, even when the specimens lack a muscularis propria.

Staging and reporting of urothelial carcinoma of the urinary bladder

“…Several studies have explored the utility of evaluating the spatial relationship of invasive tumor to the muscularis mucosae for subclassification of pT1 urothelial carcinomas. 16,[31][32][33][34][35][36][37] Muscularis mucosae consists of thin and wavy fascicles of smooth muscle frequently associated with large, thin-walled blood vessels ( Figure 9). Muscularis mucosae can be identified in 15-83% of biopsy specimens; 16,24,25,[31][32][33][34][35][36][38][39][40][41][42] however, 6% of radical cystectomy specimens do not have discernable muscularis mucosae.…”

Urothelial papillary (exophytic) neoplasms

“…Patients at risk for recurrence or progression can be identified by a variety of prognostic factors, including tumor grade, tumor stage, depth of invasion, presence of vascular or lymphatic invasion, the number and size of tumors, associated mucosal abnormalities, grade and stage of first recurrence, time to first recurrence, and numerous biological markers [18,29,34,47,52,112] The majority of stage pTa tumors are grade 1, whereas almost all stage pT1 cancers are grade 2 or 3 [26]. More than 60% of non-invasive tumors recur locally, and the remainder progress to invasion [24,40,50,52,54,64,80,103,112] Papillary tumors may have a pushing border with no desmoplastic stromal reaction and may abut the muscularis propria [1,12,66,115]. Some authors have combined pTa and pT1 cancer into a single category of "superficial" cancer, but this imprecise term was rejected by the WHO/ISUP 1998 consensus group, and we concur [33]; stratification by TNM stage is more appropriate and avoids misinterpretation.…”

Molecular Evolution and Intratumor Heterogeneity by Topographic Compartments in Muscle-Invasive Transitional Cell Carcinoma of the Urinary Bladder

“…The data show that the extent of lamina propria invasion is a clinically relevant prognostic factor for progression of pT1 TCC of the bladder (Smits et al, 1998;Younes et al, 1990). Tumors extending beyond the muscularis mucosa behave in a way similar to muscle-invasive TCC, especially if they are high-grade, reveal associated carcinoma in situ, or express nuclear TP53 (Hermann et al, 1998;Smits et al, 1998;Younes et al, 1990).…”