[897] Using Cytokeratin Expression Pattern To Evaluate Differentiation in Urothelial Carcinoma of the Upper Urinary Tract

Joseph Heitzman, Bogdan Czerniak, Charles C Guo. UT MD Anderson Cancer Center, Houston, TX

Background: Normal urothelium consists of three cell types: basal, intermediate, and umbrella cells. Studies have found that each urothelial cell type exhibits a distinct pattern of cytokeratin (CK) expression. Limited information is available for the CK expression pattern in urothelial carcinoma of the upper urinary tract (UC-UTT) and its association with clinicopathologic features.
Design: We identified 101 cases of UC-UUT and 14 cases of squamous cell carcinoma (SqCC) of the bladder (for comparison) from our pathology files. Tissue microarrays (TMAs) were constructed using three 0.4-mm cores from each case. Immunohistochemical analysis for CK5/6, CK20, and CK14 were performed on the TMA slides. Clinicopathologic information was collected from the patients' medical records.
Results: CK expression patterns were obtained in 92 cases of UC-UUT and 13 cases of SqCC. On the basis of CK expression pattern, UC-UUT were divided into four groups as follows: basal (CK5+/CK14+/CK20-), intermediate (CK5+/CK14-/CK20-), umbrella (CK5-/CK14-/CK20+), and unclassified type (Table 1). Basal type UC had higher tumor grade and stage and more frequent metastasis than umbrella type UC. The expression of CK14, a basal cell marker, was more frequent in UC-UUT with higher tumor grade and stage. In contrast, all SqCC (n=13) showed the basal type pattern (CK5+/CK14+/CK20-).

Table 1 Patterns of CK exrpession in UC-UUT
Cell type UmbrellaIntermediateBasalUnclassifiedCK14+CK14-
No. cases 392411181973
GradeLow16 (41)*6 (25)1 (9)4 (22)4 (21)23 (32)
 High23 (59)18 (75)10 (91)14 (78)15 (79)50 (68)
StagepTa/Tis11 (28)6 (25)03 (17)3 (16)17 (23)
 pT19 (23)4 (17)1 (9)1 (6)2 (11)13 (18)
 pT29 (23)4 (17)3 (27)4 (22)5 (26)15 (21)
 pT37 (18)8 (33)2 (18)8 (44)7 (37)21 (29)
 pT43 (8)2 (8)2 (18)2 (11)2 (11)7 (10)
Metastasis 16 (41)10 (42)6 (55)14 (78)10 (53)36 (49)
* The numbers in parenthesis represent the percentage of the number of cases

Conclusions: The differentiation of UC-UUT can be evaluated according to the pattern of CK expression. Our limited study suggests that the basal type UC may be associated with higher grade and stage and more frequent metastasis than the umbrella type UC. The expression of CK14 appears to be more frequent in the UC-UUTs of higher grade and stage. Furthermore, SqCC shares the same CK expression pattern with the basal type UC, suggesting a close relationship between them. Although the findings are promising for classifying UC differentiating subtype, they need to be further studied in a large cohort of patients.
Category: Genitourinary (including renal tumors)

Wednesday, March 6, 2013 9:30 AM

Poster Session V # 159, Wednesday Morning


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