SEARCH

SEARCH BY CITATION

Keywords:

  • clinicopathological factors;
  • KAI1 expression;
  • pTa and pT1 urothelial bladder carcinoma;
  • recurrence

Abstract

  1. Top of page
  2. Abstract
  3. Introduction
  4. Methods
  5. Results
  6. Discussion
  7. Acknowledgments
  8. References

Objective:  To examine the expression of the KAI1 metastasis suppressor gene and to evaluate its relationship with tumor recurrence in primary pTa and pT1 urothelial bladder carcinoma.

Methods:  Samples were obtained from 87 patients after transurethral resection (TUR). Tumor stage and grade were reviewed in 33 patients with pTa and in 54 patients with pT1, with a mean follow-up time of 47.4 ± 30.1 months. The KAI1 protein immunohistochemical assay was performed. Prognosis was analyzed using the Kaplan–Meier method and Cox's proportional hazards model. Correlation between KAI1 expression and recurrence according to each clinicopathological factor was comparatively evaluated using the chi-squared test.

Results:  Decreased expression of KAI1 protein failed to reach statistical significance for stage (P = 0.25) or morphology of tumor stem (P = 0.19), but it was significantly related to tumor size (P = 0.016). The recurrence-free 5-year survival rates of the group with decreased KAI1 expression was 69.7%, which was significantly higher than the 22.2% for the KAI1-positive group (P < 0.0001). In univariate and multivariate analyses, decreased expression of KAI1 protein, stage pT1, tumor size >3 cm and sessile tumors were independent prognosis factors of recurrence. Despite the lower recurrence rate expected by considering only the clinicopathological factors, decreased KAI1 expression was able to identify the group with a high risk of recurrence.

Conclusions:  Downregulated KAI1 expression in bladder tumors tends to relate to stage and morphology of the tumor stem and was significantly correlated to tumor size. Decreased expression of KAI1 was associated with the degree of invasiveness and progression of the cancer and was an independent prognostic factor of recurrence in primary pTa and pT1 urothelial bladder carcinoma.


Introduction

  1. Top of page
  2. Abstract
  3. Introduction
  4. Methods
  5. Results
  6. Discussion
  7. Acknowledgments
  8. References

Bladder carcinoma is the second most common malignancy encountered by urologists; approximately 70–80% of patients with bladder carcinoma present with pTa and pT1 urothelial bladder carcinomas,1 which can be managed with transurethral resection (TUR) alone or with intravesical therapy. However, recurrence occurs in more than half of all cases of pTa and pT1 urothelial bladder carcinoma within 5 years after TUR, and the majority of patients who progress eventually succumb to their disease.2 Tumor recurrence is the most important problem in the treatment of pTa and pT1 urothelial bladder carcinoma. Different causes have been proposed to explain why tumor recurrence may appear, including the persistence of residual tumor due to incomplete resection, tumor may be present but not visible at the time of TUR, cancer cells from the primary tumor may have transplanted to other parts of the urothelium and/or it can be attributable to the continual insult of the carcinogenic process.3 Several recurrence risk factors have been reported, such as grade, stage, tumor morphology, tumor size and tumor number.4–6 Among these risk factors, the number of tumors and tumor size are considered the most important prognostic factors related to recurrence.7,8 Access to molecular biology analysis has permitted as to understand those factors involved in bladder cancer, such as chromosome 9,9 the p53 suppressor gene10 and Ki-67 antigen.11 Also, the detection of abnormal genes has become possible using clinicopathology. Recent studies have shown that multifocal bladder cancer and tumor recurrence have a monoclonal origin and suggest that tumor cells have either an intraepithelial spread or are transplanted directly to the bladder mucosa after TUR.12–15

The KAI1 metastasis suppressor gene has been examined in many cancers, including bladder carcinoma specimens and cell lines,16–20 and its expression has been related to tumor invasiveness, metastases, growth of metastatic tumors,21 cell motility and adhesion.22–24 It has been reported that decreased KAI1 expression appears at an early phase of tumor progression25–28 and is a predictor of recurrence in breast cancer and small cell lung cancer.20,29 Thus, whether examination of KAI1 gene expression could contribute to predicting the recurrence of cancer in primary pTa and pT1 bladder urothelial carcinoma is unknown. Using immunohistochemical staining, we examined KAI1 gene expression, evaluated the correlation between KAI1 expression and clinicopathological factors and also studied its effect on tumor recurrence.

Methods

  1. Top of page
  2. Abstract
  3. Introduction
  4. Methods
  5. Results
  6. Discussion
  7. Acknowledgments
  8. References

Clinical characteristics of patients

Tumor specimens were obtained from 87 patients (72 males and 15 females) with primary pTa and pT1 bladder urothelial (transitional cell) carcinoma who were treated by TUR of the bladder tumor at Mie University Hospital. The mean age of patients was 64 ± 13 years (range 34–91 years). Patients were followed up for a mean of 47.4 ± 30.1 months (range 4–78 months). After TUR, five patients underwent intravesical Bacillus Calmette–Guérin (BCG) instillation treatment and 77 patients received intravesical anticancer drug (mitomycin C and cytosine arabinoside or adriamycin) treatment. Tumor stage and grade were reviewed and determined according to the General Rule for Clinical and Pathologic Studies on Bladder Cancer of the Japanese Urological Association and the Japanese Society of Pathology,30 which is based on the TNM classification31 and World Health Organization criteria.32 Recurrent time was calculated from the time of the initial TUR-bladder tumor (Bt) until the first tumor recurrence had been confirmed by cystoscopy. These patients did not show progress defined as the presence of muscle invasion, metastasis.33 The clinicopathological characteristics of the patients are given in Table 1.

Table 1.  Clinical characteristics of patients and association between decreased KAI1 expression and clinicopathological factors in primary pTa and pT1 urothelial bladder carcinomas
Prognostic factorsTotal (%)Expression of KAI1 (%)P-value
PositiveDecreased
Histology
 Grade 123 (26.4)16 (70) 7 (30) 0.78
 Grade 256 (64.4)33 (59)23 (41) 
 Grade 3 8 (9.2) 5 (62) 3 (38) 
Pathology
 Stage pTa33 (37.9)23 (70)10 (30)0.25
 Stage pT154 (62.1)31 (57)23 (43) 
Morphology
 Papillary75 (86.2)48 (64)27 (36)0.35
 Non-Papillary12 (13.8) 6 (50) 6 (50) 
 Pedunculated60 (69.0)40 (67)20 (33)0.19
 Sessile27 (31.0)14 (52)13 (48) 
Size (cm)
 <121 (24.1)15 (71) 6 (29) 0.016
 1–349 (56.3)33 (67)16 (33) 
 >312 (13.8) 6 (50) 6 (50) 
 Unidentified 5 (5.8) 0 5 (100) 
No. tumors
 146 (52.9)29 (63)17 (37)0.12
 2–425 (28.7)14 (56)11 (44) 
 >510 (11.5) 9 (90) 1 (10) 
 Unidentified 6 (6.9) 2 (33) 4 (67) 

Immunohistochemical assays

Immunohistochemical staining was performed using the streptavidin–biotin (SAB) method. Tissue sections were obtained from formalin-fixed, paraffin-embedded samples and mounted on aminopropyltriethoxysilane-coated glass slides (DAKO, Kyoto, Japan). Tissue sections (3 µm) were deparaffinized and rehydrated. Endogenous peroxide was blocked by exposure to 0.3% hydrogen peroxide for 15 min and washed twice with phosphate-buffered saline (PBS). Subsequently, sections were placed in citric acid buffer (10 mmol/L, pH 6.0), followed by heating in a microwave oven (500 W) for five successive periods of 3 min, necessary for antigen activation. After heating, sections were allowed to cool in citrate buffer for 20 min at room temperature and were washed four times with PBS. To prevent non-specific binding, sections were blocked with a super-block (ScyTek stain kit; ScyTek Laboratories, West Logan, UT, USA) for 8 min at room temperature and washed with PBS. Sections were incubated overnight at 4°C with polyclonal serum to KAI1 (C-16) from Santa Cruz Biotechnology (Santa Cruz, CA, USA; dilution 1 : 100), as described previously,19 and washed four times with PBS. Subsequently, samples were incubated with biotinylated link antibody (ScyTek stain kit; ScyTek Laboratories) for 20 min at room temperature and washed four times with PBS. Sections were incubated with streptavidin/horseradish peroxidase (HRP) label (ScyTek stain kit; ScyTek Laboratories) for 20 min at room temperature and washed four times with PBS. After the above reaction ended, the peroxidase reaction was performed using a solution of 3,3′-diaminobenzidine (ScyTek stain kit; ScyTek Laboratories) as the chromogen substrate for 5 min. Finally, slides were lightly counterstained with hematoxylin and then observed.

In each specimen, endothelial and lymphocyte cells in tumor stroma were used as internal positive controls27 and a normal serum at the same concentration of the primary antibody was used as a negative control. When staining intensity on the cell membrane and cytoplasm appeared to be similar to that of endothelial and lymphocyte cells, it was estimated to be strong positive (2+) or moderately positive (1+). When staining intensity appeared to be similar to the negative control, it was estimated to be negative (–), if staining intensity appeared to be between positive (1+) and negative (–), it was estimated to have a weaker staining (+/–).

The staining pattern of KAI1 expression was classified as: (i) moderate (or positive) when tumor cell membranes and cytoplasm showed uniform and moderate staining or when tumor tissue staining was not uniform in intensity but more than 50% of tumor cells were stained; (ii) decreased if 5–50% of tumor cells were stained; and (iii) negative if less than 5% of tumor cells were stained for KAI1 within the tumor tissue. As a staining contrast for the expression of KAI1 protein in pTa and pT1 urothelial bladder carcinoma, tissue sections from 17 cases with non-malignant ‘normal’ adjacent urothelial and from 32 patients who underwent cystectomy with muscle-invasive bladder cancers (stage pT2–4) were evaluated at the same time.

Statistical analysis

Correlation between KAI1 expression and clinicopathological factors (grade, stage, morphology, tumor size and number of tumors) and an association between decreased expression of KAI1 protein and tumor recurrence according to each clinicopathological factor were evaluated comparatively by the chi-squared test. The recurrence rate for decreased KAI1 expression and each clinicopathological factor was calculated based on the Kaplan–Meier method and log-rank test. To identify the risk factors for recurrence, we performed a multivariate analysis using Cox's proportion hazard model. These calculations were performed using StatView 5.0 software (SAS Institute, Cary, NC, USA) and P < 0.05 was considered statistically significant.

Results

  1. Top of page
  2. Abstract
  3. Introduction
  4. Methods
  5. Results
  6. Discussion
  7. Acknowledgments
  8. References

Expression of KAI1 protein and clinicopathological factors

Staining was moderate or strong and uniformly spread in all 17 cases of ‘normal’ adjacent urothelial tissue of the bladder (Fig. 1a). In pTa and pT1 bladder urothelial carcinoma, the staining intensity was lower than for normal epithelial cells and ranged from uniform intense to negative staining or exhibited a heterogeneous staining pattern that has been described previously.19 Fifty-four cases (62.1%) were classified as moderate expression (or positive; Fig. 1b) and 33 cases (37.9%) had decreased expression (Fig. 1c,d), including 29 cases with less than 50% of stained tumor cells and four cases with no staining within the tumor tissue. In multiple tumors, a total of 116 tumors were investigated and 41 tumors (35.3%) were recorded as having the poorest staining pattern, exhibiting most staining at the surface of the tumor, secondly at fragments or heterogeneously in fragments (Fig. 1c) and at the base of tumors; these different staining patterns were also seen in large tumors (size >3 cm). In invasive bladder cancers, only three cases (9.4%) were classified as moderately stained and expression of KAI1 protein was significantly lower (P < 0.0001) compared with the 62.1% found in pTa and pT1 tumors.

image

Figure 1. (a) The ‘normal’ adjacent urothelial tissue of bladder carcinoma exhibited a uniform, moderate to strong staining of cell membranes and cytoplasm (original magnification ×400). (b) Moderate (or positive) KAI1 expression. Tumor cells showed a uniform and moderately stained membrane and cytoplasm (original magnification ×400.) (c,d) Decreased (or negative) KAI1 expression. Cells exhibited a non-uniform or heterogeneous staining (original magnification ×400.)

Download figure to PowerPoint

The correlation between the expression of KAI1 protein and clinicopathological factors in pTa and pT1 urothelial bladder carcinoma is summarized in Table 1. There was no significant difference in the expression of KAI1 protein in relation to tumor grade; seven of 23 grade 1 tumors (30%), 23 of 56 grade 2 tumors (41%) and three of eight grade 3 tumors (38%) showed decreased expression of KAI1 protein. Decreased expression of KAI1 protein was more common in stage pT1 tumors (43%) compared with stage pTa (30%). However, this difference failed to reach statistical significance (P = 0.25). Decreased expression of KAI1 protein also showed a weak relationship with the morphology and number of tumors, but this correlation was not statistically significant (P > 0.05). Decreased ex-pression of KAI1 protein was significantly related to tumor size (P = 0.016).

Decreased KAI1 expression and tumor recurrence

In the present study, the recurrence rate after TUR was 25.3, 36.8 and 40.2% for 1, 3 and 5 years, respectively. When recurrence factors were analyzed with KAI1 and clinicopathological factors, the recurrence-free survival rates at 5 years were significantly related to the expression of KAI1 protein (Fig. 2; P < 0.0001), stage, morphology of the tumor stem and tumor size (Table 2; P = 0.0158, P = 0.007 and P = 0.0001, respectively). Although there was a trend towards a higher recurrence rate in multiple tumors (two to four tumors), the difference was not statistically significant (P = 0.3234). Furthermore, in cases of more than five tumors, the recurrence-free survival rate at 5 years was lower (31.4%) than for cases with single tumors and, although the cause for this is uncertain, patients with multiple tumors also had lower KAI1 expression (10%; Table 1). The results of multivariate analysis concur with those of univariate analysis, namely that decreased KAI1 expression, stage pT1, sessile tumors and tumor size >3 cm are independent prognostic factors of tumor recurrence (Table 3; P = 0.0013, P = 0.031, P = 0.0026 and P = 0.014, respectively). Clinical material with a homogeneous tumor phenotype and consistent management are more relevant for testing new markers. We comparatively evaluated differences in expression of KAI1 protein between the recurrence and non-recurrence groups according to each clinicopathological factor. Despite the low recurrence risk in univariate analysis for low grade, stage pTa, papillary tumors, tumor diameter <3 cm and single tumors (Table 2), when decreased KAI1 expression was used, these factors also indicated an increased risk of recurrence (Table 4). These results show that decreased KAI1 expression can identify patients with a higher chance of recurrence among those considered phenotypically at a low risk of recurrence.

image

Figure 2. Kaplan–Meier method for determining tumor recurrence-free survival rates of pTa and pT1 urothelial bladder carcinoma patients with either decreased or positive KAI1 expression. (······), decreased KAI1 expression (n = 33); (––––), positive KAI1 expression (n = 54; P < 0.0001).

Download figure to PowerPoint

Table 2.  Five-year recurrence-free survival rates according to each clinicopathologic factors in primary pTa and pT1 urothelial bladder carcinomas
Prognostic factorsProbability of recurrence (%)P-value
1 year3 years5 yearsLog-rank test
Histology
 Grade 1 5 (21.7) 9 (39.1) 9 (39.1)NS
 Grade 215 (26.8)20 (35.7)22 (39.6) 
 Grade 3 2 (25.0) 3 (37.5) 4 (68.8) 
Pathology
 Stage pTa 5 (15.2) 8 (24.2) 8 (24.2)0.0158
 Stage pT117 (31.5)24 (44.4)27 (51.3) 
Morphology
 Papillary21 (28.0)28 (37.3)30 (40.3)NS
 Non-Papillary 1 (8.3) 4 (33.3)  5 (42.9) 
 Pedunculated14 (23.3)16 (26.7)18 (30.4)0.007
 Sessile 8 (29.6)16 (59.3)17 (63.3) 
Size (cm)
 <1 3 (14.3) 6 (28.6) 6 (28.6)0.0001
 1–311 (22.4)13 (26.5)15 (31.0) 
 >3 7 (58.3) 9 (75.0) 10 (87.5) 
 Unidentified 1 (20.0) 4 (80.0)  4 (80.0) 
No. tumors
 110 (21.7)14 (30.4)16 (35.2)NS
 2–4 7 (28.0)13 (52.0)13 (52.0) 
 >5 2 (20.0) 2 (20.0)  3 (31.4) 
 Unidentified 3 (50.0) 3 (50.0)  3 (50.0) 
Table 3.  Independent prognostic indicators for recurrence selected by multivariate analysis with Cox's proportional hazards regression test in primary pTa and pT1 urothelial bladder carcinomas
Prognostic factorsHazard rate95% CIP
  1. CI, confidence interval.

Stage (pT1 vs pTa)2.511.09–5.790.031
Size (>3 vs <1 cm)3.821.31–11.140.0143
Morphology (sessile vs pedunculate)3.531.55–8.040.0026
KAI1 expression (decreased vs positive)3.921.70–9.010.0013
Table 4.  Association between KAI1 expression and recurrence in subgroup according to each clinicopathologic factor and intravesical treatment in primary pTa and pT1 urothelial bladder carcinomas
Prognostic factorsExpression of KAI1 (–/+)χ2 test
RecurrenceNon-recurrenceRR (95% CI)P
  1. BCG, Bacillus Calmette–Guérin; MAC, mitomycin C, adriamycin and cytosine arabinoside; (–/+), decreased/positive expression of KAI1 protein; RR, relative risk; CI, confidence interval.

Histology
 Grade 1 5/42/12 7.5 (1.0–55.0) 0.036
 Grade 216/67/2710.3 (2.9–36.0) 0.0001
 Grade 3 2/21/3 3.0 (0.2–59.9) 0.47
Pathology
 Stage pTa 6/24/2115.8 (2.3–107.9) 0.0016
 Stage pT117/106/21 6.0 (1.8–19.7) 0.0025
Morphology
 Papillary20/107/3810.9 (3.6–32.9)<0.0001
 Non-Papillary 3/23/4 2.0 (0.2–20.6) 0.56
 Pedunculated11/79/33 5.8 (1.7–19.1) 0.0028
 Sessile12/51/921.6 (2.1–218.6) 0.0023
Size (cm)
 <1 3/33/12 4.0 (0.5–30.8) 0.17
 1–310/55/2911.6 (2.8–48.6) 0.0003
 >3 6/40/2 0.12
 Unidentified 4/01/0
No. tumors
 111/56/24 8.8 (2.2–35.2) 0.001
 2–4 8/53/9 4.8 (0.9–26.8) 0.07
 >5 1/20/7 0.11
 Unidentified 3/01/2 0.08
Intravesical
 MAC18/109/40 8.0 (2.8–23.1)<0.0001
 BCG 2/11/1 2.0 (0.1–78.3) 0.71
 Non-treatment 3/10/1 0.17

Discussion

  1. Top of page
  2. Abstract
  3. Introduction
  4. Methods
  5. Results
  6. Discussion
  7. Acknowledgments
  8. References

The KAI1 gene encodes a protein consisting of 267 amino acids and belonging to a structurally distinct family of leukocyte surface glycoproteins, being a member of the transmembrane 4 superfamily (TM4SF). The KAI1 gene was isolated from human chromosome 11p11.2 and was shown to suppress metastasis when introduced into rat AT6.1 prostate cancer cells.16 Decreased expression of this gene may be involved in the malignant progression of prostate and other cancers.16 Downregulation of the KAI1 gene during progression of cancer does not commonly involve either mutation or allelic loss of the KAI1 gene17 and is not associated with methylation of the promoter or p53 regulation.34 Although the mechanisms of action of the KAI1 protein have not been fully elucidated, some clues are emerging and it seems that, like cell surface glycoproteins, the KAI1 protein may play an important role in signal transduction.35

In the present study, KAI1 expression was examined using immunohistochemistry.29,36 Because in the present study patients in both the recurrence and non-recurrence groups had the same type of urothelial carcinoma (transitional cell) and treatment was consistent with the stage of the disease, we were able to analyze the data comparatively. Because KAI1 is a member of the TM4SF, positive staining for the protein should be observed essentially at the cell membrane. However, in formalin-fixed, paraffin-embedded samples, the modification of which appears to be substantially altered in the presence of the human T-cell leukemia virus type 1 (HTLV-1) genome, immunoreactivity for KAI1 that could have prognostic value is observed, exhibiting specific cytoplasmic localization of the protein in the cells.37 In the normal papilla of Vater, esophageal tissue or primary tumor,18,38KAI1 immunoreactivity was also demonstrated in the cytoplasm and at the cell membranes. In the present study, we used a rabbit polyclonal antibody, with epitope mapping at the C-terminus of metastasis suppressor protein (KAI1) of human origin, and found that KAI1 was expressed abundantly in normal urothelial tissue, but was downregulated in pTa and pT1 urothelial bladder carcinoma and further downregulated in muscle-invasive bladder cancers (stage pT2–4). Staining of carcinoma cells was weaker than of normal epithelial cells. We considered decreased KAI1 protein expression to occur when a non-uniform staining pattern was observed and the proportion of stained cells was less than 50% within the tumor tissue. The non-uniform staining pattern correlates with loss of KAI1 expression.25,39 In advanced bladder carcinoma, an abnormal or heterogeneous immunostaining pattern was defined as negative staining and was significantly related to tumor stage and grade.19 In the present study, these poorest staining patterns were exhibited most at the tumor surface, second at fragments or heterogeneously in fragments and at the base of the tumors. These different staining patterns were also seen at the top more than at base of large tumors, suggesting that cell desquamation maybe more pronounced in pTa and pT1 urothelial bladder carcinoma. Although the malignant activity of pTa and pT1 urothelial bladder carcinoma was lower than the muscle-invasive bladder cancers, decreased expression of KAI1 also showed a tendency to relate to clinicopathological factors, including grade and stage, and was significantly related to tumor size. This level of KAI1 expression has been described previously.40 Our results suggest that this evaluation is a reasonable approach for examining the expression of the KAI1 metastasis suppressor gene in pTa and pT1 urothelial bladder carcinoma.

Identification of gene expression patterns in superficial and invasive bladder cancer gives us a better understanding of those genes related to encoding proteins involved in cell proliferation, oncogenes and growth factors, cell adhesion, immunology, transcription, proteinases and ribosomes.41 Recurrence of pTa and pT1 urothelial bladder carcinoma is a complex process in which many genes and steps participate and is related to invasiveness, spread, transplant, adhesion and the proliferation ability of neoplastic cells. The function of the KAI1 gene is closely correlated to the invasive and reimplantation characteristics of tumor cells in the bladder wall and/or the spreading of tumor cells via expansion within the urothelium, which was thought to be the main cause of the recurrence of pTa and pT1 urothelial bladder carcinoma.12–15 Univariate and multivariate analysis of results of the present study demonstrated that decreased KAI1 expression is significantly related to the recurrence of tumors and that it is also an independent prognostic factor of recurrence in pTa and pT1 urothelial bladder carcinoma.

Recurrent tumors have a similar biological potential as the original tumor and behave in a similar manner.14 To prevent tumor recurrence, it is important to recognize various biological factors and clinicopathological characteristics in each individual case. Previously, we examined the correlation between the tumor repressor gene p53, Ki-67 antigen, c-erbB-2 oncoprotein and tumor recurrence in pTa and pT1 urothelial bladder carcinoma. When all these factors became negative, the tumor recurrence rate was significantly low, combinational analysis of two factors resulting in a larger significance than analysis of a single factor, but there was no significant correlation between decreased expression of KAI1 protein and each of these factors. In the present study, subgroup analysis according to each clinicopathological factor showed that patients with decreased KAI1 expression have a high relative risk of recurrence, even for patients with a low grade, stage pTa, papillae, tumor diameter 1–3 cm and single tumor, which are supposed to indicate a lower recurrence rate. Intravesical treatment, especially BCG instillation, is able to prevent the recurrence of some tumors, but when decreased expression of KAI1 protein is detected, the follow-up regimen should be evaluated. Although the clinical material available for subgroup analysis is small, tumors were phenotypically similar and the treatment consistent with the characteristics of the tumors, which makes the results more relevant for testing new markers. Thus, analysis of the KAI1 protein can be useful for medical practice, because decreased KAI1 expression occurs during the progression of cancer, when the biological behavior of the tumor changes from low risk to high risk, permitting the identification of those patients in whom the cancer is likely to recur.

In conclusion, decreased expression of KAI1 protein was related to stage and morphology of the tumor stem and was significantly correlated with tumor size. Decreased KAI1 expression was associated with the degree of invasiveness and progression of cancer and was an independent prognostic factor for tumor recurrence in primary pTa and pT1 urothelial bladder carcinoma. Additional larger studies are needed to corroborate the validity of these observations and the role of this metastasis suppress gene in the evaluation of primary pTa and pT1 urothelial bladder carcinoma.

Acknowledgments

  1. Top of page
  2. Abstract
  3. Introduction
  4. Methods
  5. Results
  6. Discussion
  7. Acknowledgments
  8. References

We thank Professor Taizou Shiraishi (Department of Pathology, Faculty of Medicine, Mie University) for advice on histopathological diagnoses and immunostaining.

References

  1. Top of page
  2. Abstract
  3. Introduction
  4. Methods
  5. Results
  6. Discussion
  7. Acknowledgments
  8. References
  • 1
    De Vere White RW, Stapp E. Predicting prognosis in patients with superficial bladder cancer. Oncology 1998; 12: 171723.
  • 2
    Herr HW. Natural history of superficial bladder tumors: 10- to 20-year follow-up of treated patients. World J. Urol. 1997; 15: 848.
  • 3
    Okajima E, Hirao K. Anti-cancer drug intravesical treatment to superficial bladder tumor. In: Yoshida O (ed.). Developing with New Bladder Tumor Treatment. Kanehara, Tokyo, 1993; 105111(in Japanese).
  • 4
    Takashi M, Murase T, Mitsuya H et al. Statistical analysis of recurrence factors in superficial bladder cancer: Estimation with Cox's proportional hazards model. Jpn. J. Urol. 1987; 78: 3949 (in Japanese).
  • 5
    Kobashi K. Statistical analysis of recurrent factors in superficial bladder cancer: Natural history of superficial bladder cancer. Jpn. J. Urol. 1993; 84: 118896 (in Japanese).
  • 6
    Allard P, Bernard P, Frader Y, Tetu B. The early clinical course of primary Ta and T1 bladder cancer: A proposed prognostic index. Br. J. Urol. 1998; 81: 6928.
  • 7
    Brausi M, Collette L, Kurth K et al. Variability in the recurrence rate at first follow-up cystoscopy after TUR in stage Ta T1 transitional cell carcinoma of the bladder: A combined analysis of seven EORTC studies. Eur. Urol. 2002; 41: 52331.
  • 8
    Millan-Rodriguez F, Chechile-Toniolo G, Salvador-Bayarri J, Palou J, Vicente-Rodriguez J. Multivariate analysis of the prognostic factors of primary superficial bladder cancer. J. Urol. 2000; 163: 738.
  • 9
    Simoneau M, LaRue H, Aboulkassim TO, Meyer F, Moore L, Fradet Y. Chromosome 9 deletions and recurrence of superficial bladder cancer: Identification of four regions of prognostic interest. Oncogene 2000; 19: 631723.
  • 10
    Krause FS, Feil G, Bichler KH. Immunohistochemical examinations (Ki67, p53, nm23) and DNA cytophotometry in bladder cancer. Anticancer Res. 2000; 20: 50238.
  • 11
    Oosterhuis JW, Schapers RF, Janssen-Heijnen ML, Smeets AW, Pauwels RP. MIB-1 as a proliferative marker in transitional cell carcinoma of the bladder. Cancer 2000; 88: 2598605.
  • 12
    Simon R, Eltze E, Schafer KL et al. Cytogenetic analysis of multifocal bladder cancer supports a monoclonal origin and intraepithelial spread of tumor cells. Cancer Res. 2001; 61: 35562.
  • 13
    Van Tilborg AA, De Vries A, De Bont M, Groenfeld LE, Van Der Kwast TH, Zwarthoff EC. Molecular evolution of multiple recurrent cancers of the bladder. Hum. Mol. Genet. 2000; 9: 297380.
  • 14
    Dalbagni G, Ren ZP, Herr H, Cordon-Cardo C, Reuter V. Genetic alterations in TP53 in recurrent urothelial cancer. A longitudinal study. Clin. Cancer Res. 2001; 7: 2797801.
  • 15
    Hartmann A, Rosner U, Schlake G et al. Clonality and genetic divergence in multifocal low-grade superficial urothelial carcinoma as determined by chromosome 9 and p53 deletion analysis. Lab. Invest. 2000; 80: 70918.
  • 16
    Dong JT, Lamb PW, Rinker-Schaeffer CW et al. KAI1, a metastasis suppressor gene for prostate cancer on human chromosome 11p11.2. Science 1995; 268: 8846.
  • 17
    Dong JT, Suzuki H, Pin SS et al. Down-regulation of the KAI1 metastasis suppressor gene during the progression of human prostatic cancer infrequently involves gene mutation or allelic loss. Cancer Res. 1996; 56: 438790.
  • 18
    Friess H, Guo XZ, Tempia-Caliera AA et al. Differential expression of metastasis-associated genes in papilla of Vater and pancreatic cancer correlates with disease stage. J. Clin. Oncol. 2001; 19: 242232.
  • 19
    Ow K, Delprado W, Fisher R et al. Relationship between expression of the KAI1 metastasis suppressor and other markers of advanced bladder cancer. J. Pathol. 2000; 191: 3947.
  • 20
    Huang CI, Kohno N, Ogawa E, Adachi M, Taki T, Miyake M. Correlation of reduction in MRP-1/CD9 and KAI1/CD82 expression with recurrences in breast cancer patients. Am. J. Pathol. 1998; 153: 97383.
  • 21
    Yang X, Wei LL, Tang C, Slack R, Mueller S, Lippman ME. Overexpression of KAI1 suppresses in vitro invasiveness and in vivo metastasis in breast cancer cells. Cancer Res. 2001; 61: 52848.
  • 22
    Takaoka A, Hinoda Y, Satoh S et al. Suppression of invasive properties of colon cancer cells by a metastasis suppressor KAI1 gene. Oncogene 1998; 16: 144353.
  • 23
    Takaoka A, Hinoda Y, Sato S et al. Reduced invasive and metastatic potentials of kai1-transfected melanoma cells. Jpn. J. Cancer Res. 1998; 89: 397404.
  • 24
    Jackson P, Kingsley EA, Russell PJ. Inverse correlation between KAI1 mRNA levels and invasive behaviour in bladder cancer cell lines. Cancer Lett. 2000; 156: 917.
  • 25
    Uchida S, Shimada Y, Watanabe G et al. Motility-related protein (MRP-1/CD9) and KAI1/CD82 expression inversely correlate with lymph node metastasis in oesophageal squamous cell carcinoma. Br. J. Cancer 1999; 79: 116873.
  • 26
    Lombardi DP, Geradts J, Foley JF, Chiao C, Lamb PW, Barrett JC. Loss of KAI1 expression in the progression of colorectal cancer. Cancer Res. 1999; 59: 572431.
  • 27
    Liu FS, Chen JT, Dong JT et al. KAI1 metastasis suppressor gene is frequently down-regulated in cervical carcinoma. Am. J. Pathol. 2001; 159: 162934.
  • 28
    Liu FS, Dong JT, Chen JT, Hsieh YT, Ho ES, Hung MJ. Frequent down-regulation and lack of mutation of the KAI1 metastasis suppressor gene in epithelial ovarian carcinoma. Gynecol. Oncol. 2000; 78: 1015.
  • 29
    Higashiyama M, Kodama K, Yokouchi H et al. KAI1/CD82 expression in nonsmall cell lung carcinoma is a novel, favourable prognostic factor. Cancer 1998; 83: 46674.
  • 30
    Japanese Urological Association and the Japanese Society of Pathology. General Rule for Clinical and Pathological Studies on Bladder Cancer. Kanehara, Tokyo, 2001.
  • 31
    Sobin LH, Wittekind C. TNM Classification of Malignant Tumors. Wiley-Liss, New York, 1997.
  • 32
    Mostofi FK, Davis CJ, Sesterhenn IA. Histological typing of urinary bladder tumors. In: World Health Organization International Histological Classification of Tumor, 2nd edn. Springer, New York, 1999.
  • 33
    Pfister C, Moore L, Allard P et al. Predictive value of cell cycle markers p53, MDM2, p21, and Ki-67 in superficial bladder tumor recurrence. Clin. Cancer Res. 1999; 5: 407984.
  • 34
    Uzawa K, Ono K, Suzuki H et al. High prevalence of decreased expression of KAI1 metastasis suppressor in human oral carcinogenesis. Clin. Cancer Res. 2000; 28: 82835.
  • 35
    Wright MD, Tomlinson MG. The ins and outs of the transmembrane 4 superfamily. Immunol. Today 1994; 15: 58894.
  • 36
    Geradts J, Maynard R, Birrer MJ et al. Frequent loss of KAI1 expression in squamous and lymphoid neoplasms: An immunohistochemical study of archival tissues. Am. J. Pathol. 1999; 154: 166571.
  • 37
    Fukudome K, Furuse M, Imai T et al. Identification of membrane antigen C33 recognized by monoclonal antibodies inhibitory to human T-cell leukemia virus type 1 (HTLV-1)-induced syncytium formation: Altered glycosylation o f C33 antigen in HTLV-1-positive T cells. J. Virol. 1992; 66: 1394401.
  • 38
    Miyazaki T, Kato H, Shitara Y et al. Mutation and expression of the metastasis suppressor gene KAI1 in esophageal squamous cell carcinoma. Cancer 2000; 89: 95562.
  • 39
    Shinohara T, Miki T, Nishimura N et al. Nuclear factor-kappaB-dependent expression of metastasis suppressor KAI1/CD82 gene in lung cancer cell lines expressing mutant p53. Cancer Res. 2001; 61: 6738.
  • 40
    Yu Y, Yang JL, Markovic B et al. Loss of KAI1 messenger RNA expression in both high-grade and invasive human bladder cancers. Clin. Cancer Res. 1997; 3: 10459.
  • 41
    Thykjaer T, Workman C, Kruhoffer M et al. Identification of gene expression patterns in superficial and invasive human bladder cancer. Cancer Res. 2001; 61: 24929.