Detection of micrometastases in pelvic lymph nodes in patients undergoing radical cystectomy for locally invasive bladder cancer by real-time reverse transcriptase-PCR for cytokeratin 19 and uroplakin II.
OBJECTIVE
The objective of this study was to clarify the significance of micrometastases in pelvic lymph nodes in patients who underwent radical cystectomy for bladder cancer.


METHODS
We included 40 patients with locally invasive bladder cancer who underwent radical cystectomy and pelvic lymphadenectomy. Expression of cytokeratin 19 (CK19), uroplakin II (UP II), and glyceraldehyde-3-phosphate dehydrogenase (GAPDH) in 760 lymph nodes were assessed by a fully quantitative real-time reverse transcription-PCR (RT-PCR) assay. The quantification value of CK19 or UP II mRNA was described as each value relative to GAPDH mRNA. In this study, we regarded specimen in which either CK19 or UP II mRNA was positive as "presence of micrometastasis."


RESULTS
Routine pathologic examinations detected tumor cells in 29 lymph nodes from six patients. Real-time RT-PCR identified positive expression of CK19 and UP II mRNAs in 49 lymph nodes from 10 patients and 98 lymph nodes from 16 patients, respectively. Of 633 lymph nodes from 34 patients with no pathologic evidence of nodal involvement, 13 nodes from five patients and 58 nodes from 10 patients were diagnosed as positive for CK19 and UP II mRNAs expression, respectively, by real-time RT-PCR. Presence of micrometastases was significantly associated with other conventional prognostic variables, including pathologic stage and microvascular invasion. Disease recurrence was occurred in eight patients, among whom four patients were negative for lymph node metastasis by routine pathologic examination and diagnosed as having micrometastasis by real-time RT-PCR assay. Furthermore, cause-specific survival rate in patients without micrometastasis was significantly higher than that in those with micrometastasis, irrespective of the presence of pathologic-positive nodes.


CONCLUSIONS
Approximately 30% of locally invasive bladder cancer shed cancer cells to pelvic lymph nodes, and disease recurrence after radical cystectomy could be explained, at least in part, by micrometastases in pelvic lymph nodes.
Kurahashi
Toshifumi
T
Department of Urology, Kobe University School of Medicine, Kobe, Japan.
Hara
Isao
I
Oka
Nobutoshi
N
Kamidono
Sadao
S
Eto
Hiroshi
H
Miyake
Hideaki
H
D015653:Cystectomy; D005260:Female; D020869:Gene Expression Profiling; D006801:Humans; D007633:Keratins / Q000032:analysis / Q000096:biosynthesis*; D008207:Lymphatic Metastasis; D008297:Male; D008565:Membrane Proteins / Q000032:analysis / Q000096:biosynthesis*; D009361:Neoplasm Invasiveness; D009364:Neoplasm Recurrence, Local; D010388:Pelvis; D011379:Prognosis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D001749:Urinary Bladder Neoplasms / Q000235:genetics / Q000473:pathology* / Q000601:surgery*; D060170:Uroplakin II
D008565:Membrane Proteins; C554658:UPK2 protein, human; D060170:Uroplakin II; D007633:Keratins