Prognostic Significance of Substaging according to the Depth of Lamina Propria Invasion in Primary T1 Transitional Cell Carcinoma of the Bladder

PURPOSE: To evaluate the prognostic significance of the depth of lamina propria invasion in primary T1 transitional cell carcinoma (TCC) of the bladder. MATERIALS AND METHODS: We retrospectively reviewed the medical records of 183 patients with primary T1 TCC of the bladder who had undergone transurethral resection (TUR) at our institution. Substaging was defined according to the depth of lamina propria invasion as follows: T1a, superficial invasion of lamina propria; T1b, invasion into the muscularis mucosa (MM); T1c, invasion beyond the MM but not to the muscularis propria. The prognostic significance of various clinicopathological variables for recurrence and progression was analyzed. RESULTS: Of the 183 patients, substaging was T1a in 119, T1b in 57, and T1c in 7 patients. The recurrence rate was 32.8% for T1a and 40.6% for T1b/c, but there was no significant difference between the two groups. The progression rate was significantly different between the two groups: 5.8% in T1a and 21.9% in T1b/c (p=0.003). The cancer-specific mortality rate was also significantly different: 4.2% in T1a and 14.0% in T1b/c (p=0.036). In the univariate analysis, microscopic tumor architecture was the only significant prognostic factor for recurrence. In the univariate and multivariate analysis concerning progression, depth of lamina propria invasion and concomitant carcinoma in situ were significant prognostic factors. CONCLUSIONS: Substaging according to the depth of lamina propria invasion in primary T1 TCC of the bladder was an independent prognostic factor for progression. This suggests that substaging would be helpful for guiding decisions about adjuvant therapies and follow-up strategies.

Significance of Invasion to the Muscularis Mucosae on the Progression of Superficial Bladder Cancer / 대한비뇨기과학회지

We tried to determine the significance of invasion to the muscularis mucosae on the progression and recurrence of the superficial bladder cancer. Muscularis mucosae was composed of the smooth muscle bundles around relatively large vessels and found in the lamina propria approximately midway between the surface mucosa and the true muscular layer, lying parallel to the mucosa. Between January 1984 and December 1993, 81 patients with diagnosed superficial bladder cancer showing lamina propria invasion (pTl) were treated by transurethral resection (TUR) at our hospital. The mean age was 59.4 years ( range, 31-86 years), the mean follow-up period was 35.3 months ( range, 13-120 months) and the male : female ratio was 69 : 12. We subclassified superficial bladder cancer showing lamina propria invasion into two groups with ( pT1b) or without ( pT1a) cancer invasion to the muscularis mucosae. The muscularis mucosae was identified in 58 (71.6%) of 81 cases. In the other cases ( 28.4% ), relatively large vessels were used as the landmark instead of the muscularis mucosae. Of 81 bladder cancers, 52 (64.2%) were diagnosed as pT1a and 29 (35.8%) as pTlb. The progression rate of pT1b cancer (41.4% ) was significantly higher than that of pT1a cancer (3.8% ) (p= 0.001). And the recurrence rate of pT1b cancer (55.2% ) was significantly higher than that of pT1a cancer ( 26.9 %)(p= 0.024). In conclusion, superficial bladder cancer invading to the muscularis mucosae has a high risk for disease progression after TUR. Careful follow-up examination and aggressive therapy should be recommended in patients with these tumors.