The role of Ki67 proliferation assessment in predicting local control in bladder cancer patients treated by radical radiation therapy

PURPOSE

To assess whether tumour proliferation as measured by Ki67 immunostaining has any predictive value for local control in bladder cancer patients treated by radiotherapy.

PATIENTS AND METHODS

Fifty-five patients suffering from infiltrating bladder carcinoma recommended for radical radiotherapy (66 Gy/6-7 weeks) were included in this study. Paraffin-embedded pre-treatment tumour sections were stained with the Ki67 antibody. The percentage of Ki67-positive nuclei was correlated with established prognostic factors, local control and survival.

RESULTS

The Ki67 index was not related to local control in our patients when the median was selected as the cut-off value. Patients with tumours with a very low (<27%) Ki67 index had better local control at 5 years (69%) than patients with tumours with greater (>27%) Ki67 expression indices (31.5%) (P<0.05; log-rank test).

CONCLUSIONS

Ki67 immunostaining was a feasible method to estimate tumour proliferation. Patients with very low proliferating tumours seemed to achieve better local control after fractionated radiotherapy compared to other patients. Further studies are needed with a greater number of patients to accurately define the role of Ki67 expression in predicting tumour repopulation during fractionated radiotherapy.

KI67 proliferation index in tumors of the upper urinary tract as related to established prognostic factors and long-term survival

OBJECTIVE

Nephroureterectomy is the standard treatment for tumors of the renal pelvis and ureter. Conservative management or indication of adjuvant treatment in these neoplasms is based mainly in histological grade and stage. The aim of this study is to assess the relation of Ki67 index with other established prognostic factors and to define its predictive value for long term survival, which could be useful in selecting the best treatment for each individual case.

METHODS

81 patients with urothelial tumors of the renal pelvis and ureter, diagnosed and treated between 1975 and 1993, comprised the present study. Ki67 immunostaining was performed in paraffin-embedded tissue. A cut-off limit of 20% was chosen. Tumor location, histological grade, histological pattern, local (T), nodal (N), vascular and perineural invasion and stage (TNM) were assessed in relation to the proliferation index and as prognostic criteria for survival in both univariate and multivariate analysis.

RESULTS

The Ki67 proliferation index was found to be related to grade (p < 0.001), T (T0 vs T1-4; p < 0.01), N (p < 0.038), TNM categories (stage 0 vs I-IV; p < 0.048) and perineural invasion (p < 0.01). There was a marginal relation to vascular invasion (p < 0.11). Survival was better for the patients with low proliferating tumors (90%) than for high proliferating ones (67%) (p < 0.02). In the multivariate analysis only T stage was statistically significant (p < 0.01) but a highly suggestive trend was found for the Ki67 index (p < 0.07).

CONCLUSIONS

Tumor proliferation assessed by Ki67 immunostaining is related to the progression of the disease and proved to be of predictive value for long-term survival in tumors of the renal pelvis and ureter. The Ki67 index is able to detect high-risk patients that could not be cured by radical surgery alone, raising the need for some type of aduvant treatment in these cases. The treatment predictive effect observed in low grade-low stage cases suggests its possible utility in patients managed conservatively.

Overexpression of p53 in transitional cell carcinoma of the renal pelvis and ureter. Relation to tumor proliferation and survival

BACKGROUND

Clinical management of patients with tumors of the upper urinary tract is based mainly on histologic grade and stage of the tumors. In recent years, tumor proliferation has also proved to be an important factor in determining the prognosis of these and other transitional cell tumors. The aim of this study was to assess the role of p53 in regulating cell proliferation and tumor progression and to define its value in predicting the long term survival of patients with these tumors. Such information could be of use in selecting treatment in individual cases.

METHODS

Eighty-three patients with urothelial tumors of the renal pelvis and ureter diagnosed and treated between 1975 and 1993 were included in this study. p53 immunostaining was performed on paraffin embedded tissue. Tumor location, histologic grade, histologic pattern, tumor proliferation by Ki-67, local (T classification), lymph node (N classification), vascular and perineural invasion, and clinical stage (TNM) were assessed in relation to p53 overexpression (Mann-Whitney U test and analysis of variance comparisons) and as prognostic factors for survival in both univariate analysis (log rank test) and multivariate analysis (Cox proportional hazards model).

RESULTS

Overexpression of p53 was related to tumor proliferation as assessed by Ki-67 (P < 0.01), T classification (Ta vs. T1-4; P < 0.01), N classification (P < 0.054), and TNM staging (Stage 0 vs. I-IV; P < 0.01). There was also a statistically significant relation to vascular (P < 0.002) and perineural invasion (P < 0.04). Fifteen-year actuarial survival for the whole group was 75%. Patients having tumors with low p53 overexpression (< 30% of stained nuclei) had a better survival rate (88%) than those having tumors with high (> 30%) p53 overexpression (65%) (P < 0.02), and this effect reached statistical significance with high grade (P < 0.02) and infiltrating tumors (P < 0.04). Patients with low p53 and Ki-67 expression had a 15-year survival rate of 100%; in contrast, patients with overexpression of both markers had a 15-year survival rate of 61% (P < 0.003). In a multivariate analysis, only T classification (P < 0.001) and p53-Ki-67 expression (P < 0.026) were statistically significant.

CONCLUSIONS

Overexpression of p53 is related to increased tumor proliferation and disease progression and is of value in determining the long term survival of patients with tumors of the renal pelvis and ureter. p53 immunostaining can be used to distinguish low risk patients in the theoretically unfavorable high grade, high stage group, and when used together with Ki-67 index, it is a predictive factor for survival.

Overexpression of p53 in transitional cell carcinoma of the renal pelvis and ureter. Relation to tumor proliferation and survival

BACKGROUND

Clinical management of patients with tumors of the upper urinary tract is based mainly on histologic grade and stage of the tumors. In recent years, tumor proliferation has also proved to be an important factor in determining the prognosis of these and other transitional cell tumors. The aim of this study was to assess the role of p53 in regulating cell proliferation and tumor progression and to define its value in predicting the long term survival of patients with these tumors. Such information could be of use in selecting treatment in individual cases.

METHODS

Eighty-three patients with urothelial tumors of the renal pelvis and ureter diagnosed and treated between 1975 and 1993 were included in this study. p53 immunostaining was performed on paraffin embedded tissue. Tumor location, histologic grade, histologic pattern, tumor proliferation by Ki-67, local (T classification), lymph node (N classification), vascular and perineural invasion, and clinical stage (TNM) were assessed in relation to p53 overexpression (Mann-Whitney U test and analysis of variance comparisons) and as prognostic factors for survival in both univariate analysis (log rank test) and multivariate analysis (Cox proportional hazards model).

RESULTS

Overexpression of p53 was related to tumor proliferation as assessed by Ki-67 (P < 0.01), T classification (Ta vs. T1-4; P < 0.01), N classification (P < 0.054), and TNM staging (Stage 0 vs. I-IV; P < 0.01). There was also a statistically significant relation to vascular (P < 0.002) and perineural invasion (P < 0.04). Fifteen-year actuarial survival for the whole group was 75%. Patients having tumors with low p53 overexpression (< 30% of stained nuclei) had a better survival rate (88%) than those having tumors with high (> 30%) p53 overexpression (65%) (P < 0.02), and this effect reached statistical significance with high grade (P < 0.02) and infiltrating tumors (P < 0.04). Patients with low p53 and Ki-67 expression had a 15-year survival rate of 100%; in contrast, patients with overexpression of both markers had a 15-year survival rate of 61% (P < 0.003). In a multivariate analysis, only T classification (P < 0.001) and p53-Ki-67 expression (P < 0.026) were statistically significant.

CONCLUSIONS

Overexpression of p53 is related to increased tumor proliferation and disease progression and is of value in determining the long term survival of patients with tumors of the renal pelvis and ureter. p53 immunostaining can be used to distinguish low risk patients in the theoretically unfavorable high grade, high stage group, and when used together with Ki-67 index, it is a predictive factor for survival.