Negative p53/Positive p21 Immunostaining Is a Predictor of Favorable Response to Chemotherapy in Patients with Locally Advanced Bladder Cancer

The relationship between clinical response to DNA-damaging drugs and p53 and p21 status in patients with locally advanced transitional cell carcinoma (TCC) of the bladder was assessed. The response to intraarterial chemotherapy (IAC) comprising 100 mg/m² of cisplatin (CDDP) and 40 mg/m² of pirarubicin (THP) and the prognosis were assessed in 23 patients (the mean follow-up period was 19 months). The p 53 gene status of tumors was analyzed at exons 5–8 using polymerase chain reaction-single strand conformation polymorphism analysis in 19 patients, and paraffinembedded tumor sections were immunostained for p⁵³ and p²¹ in 23 patients. The overall objective response rate (incidence of good responders) was 70%. The negative p53 group ( n =17) showed a significantly higher objective response rate than the positive p53 group ( n =6) (82% vs. 33%; P =0.045). The p 53 gene status or p21 staining status was not significantly associated with responsiveness. When the p53 and p21 immunostaining results were combined, good responders were more accurately predicted than by p53 staining status alone; the negative p53/positive p21 group ( n =12) showed an objective response rate of 92%, which was significantly higher than that of the positive p53 and/or negative p21 group (45%, n =11) ( P =0.027). Cause-specific survival of the negative p53 group was significantly superior to that of the positive p53 group ( P =0.015). Negative p53/positive p21 immunostaining is a possible predictor of favorable chemotherapeutic response in patients with TCC of the bladder.     

Prognostic value of p53 and MIB-1 in transitional cell carcinoma of the urinary bladder with regional lymph node involvement

BACKGROUND: The effect of p53 protein expression and MIB-1 proliferative activity on survival and chemotherapeutic response in patients with lymph node (LN)-positive transitional cell carcinoma (TCC) of the urinary bladder remains unclear. The objective of this study was to assess the ability of these markers to predict disease-associated outcomes and response to chemotherapy in a cohort of patients with LN-positive TCC. METHODS: The authors examined the expression of p53 and MIB-1 in the LN metastases from 139 patients who underwent cystectomy for TCC at their institution. P53 and MIB-1 nuclear staining were quantified using an image-analysis system. Cox proportional hazards regression models were used to test associations of these markers with death from TCC, distant metastases, and local recurrence for all patients and in the subset of patients who were treated with adjuvant chemotherapy. RESULTS: The median p53 and MIB-1 indices were 45.2% and 30.3%, respectively. The median follow-up was 4.5 years (range, 0.1-10 years). There were no statistically significant associations noted between the p53 and MIB-1 indices and the outcomes studied. When the analysis was limited to patients who were treated with adjuvant chemotherapy (n = 37 patients), the p53 index was found to have no prognostic value; however, there was a significant association between MIB-1 and distant metastases (P = 0.049). When disease-specific survival rates were stratified according to p53 index and chemotherapy, patients exhibited a response to chemotherapy regardless of p53 index. CONCLUSIONS: p53 and MIB-1 were not found to be associated significantly with disease-related outcomes in patients with LN-positive TCC. Adjuvant chemotherapy appeared to be effective regardless of p53 status. MIB-1 may prove useful in predicting response to chemotherapy.     

Tumor mapping of regional immunostaining for p21, p53, and mdm2 in locally advanced bladder carcinoma

BACKGROUND: The aim of this study was to elucidate the associations among immunostaining for p53, p21, and mdm2; their respective expression within each tumor; and the value of these variables for predicting treatment outcome after cystectomy for patients with locally advanced bladder carcinoma. METHODS: The hospital records from all 173 patients treated with cystectomy for locally advanced urothelial bladder carcinoma between 1967 and 1992 were retrospectively reviewed. Three consecutive sections from biopsies taken before any treatment were stained using the standard immunohistochemical technique for p53, p21, and mdm2, respectively. The cutoff limit was 20% or more for positive p53 expression and 10% or more for positive p21 and mdm2 expression. RESULTS: Positive immunostaining was observed for p53 in 98 tumors (57%), for p21 in 89 tumors (51%), and for mdm2 in only 16 tumors (9%). The only association found between immunostaining for the three antibodies was that most mdm2-positive tumors had positive p21 expression. Tumor mapping of regional immunostaining showed no association between immunostaining for p53 and p21. In a proportional hazards analysis, no association was found between the results of immunostaining for the three antibodies and treatment outcome. CONCLUSIONS: Positive or negative expression of p53, p21, or mdm2, or combinations of these, was not associated with cancer specific mortality after cystectomy for bladder carcinoma. There was no association between immunostaining for p21 and p53, whereas positive immunostaining for mdm2 was observed in a minority of the tumors. These results indicate that, in addition to p21, p53, and mdm2, there are other oncoproteins and tumor suppressor proteins along the p53 pathway that are involved in tumor development and progression.     

Relevance of p53, bcl-2 and Rb expression on resistance to cisplatin-based chemotherapy in advanced non-small cell lung cancer

PURPOSE: Tumors with p53 overexpression have been associated with enhanced resistance to cisplatin-based chemotherapy in a few and small studies involving non-small cell lung cancer. The relationships and interactions between p53, Rb and bcl-2 immunostaining, clinical parameters and response to cisplatin-based chemotherapy were evaluated in the present study. EXPERIMENTAL DESIGN: Histological specimens obtained by bronchial or fine-needle biopsy from patients who underwent cisplatin-based chemotherapy between 1992 and 1999 were evaluated by immunostaining. RESULTS: There were 102 patients, 88 men. Median age was 63 years; 47 had stage III and 55 stage IV disease. Forty-six tumor samples (45%) had positive immunostaining for p53, 61 (59%) had negative immunostaining for Rb and 8 (8%) had positive immunostaining for bcl-2. The response rate of the group with p53 positive immunostaining was 26% versus 57% of the p53 negative group (P=0.004). In multivariate analyses p53 positive immunostaining was identified as an independent predictive factor for resistance to cisplatin-based chemotherapy (P=0.006). CONCLUSIONS: Our study confirmed an association of p53 immunostaining and response rate of patients treated with cisplatin-based chemotherapy.     

Clinical significance of p53, MDM2 and bcl-2 expression in transitional cell carcinoma of the bladder

We investigated the prognostic and predictive relevance of p53, MDM2, and bcl-2 protein expression in patients with transitional cell carcinoma (TCC) of the bladder. The expression of p53, MDM2 and bcl-2 protein was studied by immunohistochemical methods in paraffin-embedded specimens from 119 patients whose clinicopathologic data confirmed TCC of the bladder. Multivariate analyses of prognostic factors were performed, and correlations with classical clinicopathologic parameters were examined. Sixty-one, 12, and 17% of cases were considered positive for expression of p53, MDM2 and bcl-2, respectively. p53 expression correlated with stage (p=0.0209), but not MDM2 and bcl-2 with any clinicopathologic parameters. In Cox's regression analysis, staging demonstrated a statistically worse prognosis (hazard ratio 1.636; p=0.0059) while bcl-2 (hazard ratio 0.179; p=0.0474) expression showed favorable prognosis in stage T2-4 invasive TCC of the bladder. Co-expression with p53/MDM2 (hazard ratio 0.367; p=0.0401) and p53/bcl-2 (hazard ratio 3.487; p=0.0111) overexpression were associated with favorable and unfavorable prognosis in stage T2-4 invasive TCC of the bladder, respectively. Our results indicate that staging is the most useful parameter to predict clinical outcome in patients with TCC of the bladder. Determinations of bcl-2 and co-expression p53/MDM2 and p53/bcl-2 may be useful for predicting tumor behavior and prognosis in stage T2-4 invasive type TCC of the bladder.     

Predictive effect of p53 and p21 alteration on chemotherapy response and survival in locally advanced adenocarcinoma of the esophagus

BACKGROUND: Cell cycle regulating proteins (p53/p21) and proliferation index Ki-67 have been associated with prognosis and response to chemotherapy. The aim of this study was to determine the significance of these molecular markers on tumor response and prognostic effect in a group of esophageal cancer patients treated with neoadjuvant chemotherapy. PATIENTS AND METHODS: Immunohistochemical expression of p53/p21 and Ki-67 was examined in pre-treatment biopsy specimen of 30 patients, in phase II neoadjuvant studies for locally advanced adenocarcinoma of the esophagus, who underwent surgery. Seven patients (23%) had progressive disease. Resection was achieved in all responders (n=23; 77%) and histochemical expression of the above-mentioned proliferating markers was examined in pre-treatment and resection specimens after chemotherapy. RESULTS: Responders had a significantly better survival compared to non-responders (p=0.001). Expression of p53, p21 and high Ki-67 in pre-treatment specimens was 73% (22/30), 63% (19/30) and 30% (10/30), respectively and was not related to response to chemotherapy. However, alteration in expression of p53-positivity in the pre-treatment specimens to p53-negativity in the resection specimens and p21-negativity to p21-positivity in 6 of the 23 (26%) resected tumors was correlated with better response and survival (p=0.011). CONCLUSION: Data from this study showed that alteration of p53 and p21 expression rather than the initial expression seems to be related to chemotherapy response and overall survival in patients with esophageal adenocarcinoma.     

Expression of p53 in urothelial cell cultures from tumour-bearing and tumour-free patients.

An explant culture technique was used to culture normal urothelium from patients with muscle-invasive bladder cancer (transitional cell carcinoma, TCC) (n = 11) and from non-tumour-bearing patients (n = 60). Cell cultures were examined for expression of p53 using the monoclonal antibody p53-240. There was a statistically significant increase in p53 expression in normal urothelial cell cultures from patients with TCC (P < 0.0005). Normal urothelial cultures from patients with TCC also showed more rapid proliferation in vitro when compared with non-tumour-bearing patients (P < 0.0005). A subgroup of non-tumour-bearing patients (n = 14) showed > 5% of cells expressing p53. p53 expression in this subgroup was found to correlate with cell proliferation in vitro (r2 = 0.766). None of these urothelial specimens was observed to express p53 when paraffin-embedded preparations were stained with p53-D07 antibody prior to culture. The rate of cellular proliferation in this subgroup did not differ from that of normal urothelium from TCC patients. Twenty-two paraffin-embedded, muscle-invasive TCC specimens were also evaluated for p53 expression using p53-D07. The expression of p53 in these tumours did not differ from that observed in normal urothelial cell cultures from patients with TCC (P = 0.26). This study identifies an overexpression of p53 in normal urothelial cells from patients with TCC and in proliferating cultures from a significant subgroup of patients without malignant disease. Increased p53 expression in normal cultured urothelial cells from patients with bladder cancer implies a global change in the mechanisms controlling urothelial cell division. This may represent an early step in the pathway to carcinogenesis.     

Absence of p21 expression is associated with abnormal p53 in human breast carcinomas.

The p53 tumour-suppressor gene is important in the regulation of cell growth and apoptosis, and loss of functional wild-type activity may be associated with tumour formation and resistance to therapy. Differentiation of functionally normal wild-type protein from mutant or abnormal protein remains difficult using either immunohistochemical assays or mutational DNA sequencing. p21(WAF1/CIP1) (p21) is induced by wild type p53 and plays an important role in promoting cell cycle arrest. To test the hypothesis that p21 protein expression may act as a downstream marker of tumours from patients with locally advanced breast cancer before treatment with doxorubicin, pretreatment p53 status had been characterized in 63 tumours by p53 protein immunostaining and DNA mutational analysis. There was a significant association between immunostaining for p53 and the presence of p53 mutations (P = 0.01). Of 56 patients available for determination of p21, 31 (55%) expressed p21 protein. Twenty-eight out of 31 patients (90%) positive for p21 had low negative p53 protein expression, whereas only 3 of 13 patients (23%) with high p53 expressed p21 (P = 0.009). No association was seen between p21 protein expression and p53 mutations (P = 0.24). The combination of p53 and p21 immunostaining results improved the specificity of the immunostaining but at a cost of significant reduction in sensitivity. Immunohistochemical assessment of p21 protein expression is inversely associated with abnormal p53 protein in human breast cancer. The detection of p21 protein expression in combination with p53 protein expression did not improve the ability of immunohistochemistry (IHC) to differentiate between normal and mutant p53 protein.     

Significant difference in p53 and p21 protein immunoreactivity in HPV 16 positive and HPV negative breast carcinomas

Human papillomavirus (HPV) 16 has previously been found in 19/41 breast carcinomas (46%) in women with a history of HPV 16 positive CIN III lesions. There was no significant difference in distribution of histological subtypes, mean or median tumour diameter or number of regional lymph node metastases in the HPV positive and HPV negative breast carcinoma groups. P53, p21 and c-erbB-2 proteins were analysed by immunohistochemistry in the HPV 16 positive and HPV negative breast carcinomas. There was a significant difference in p53 and p21 protein immunoreactivity between HPV 16 positive and HPV negative breast carcinomas (p=0.0091 and p=0.0040), with a significant less detectable p53 and p21 protein immunoreactivity in the HPV 16 positive cases. There was also a significant difference in the coexpression of p53/p21 between the HPV 16 positive and HPV 16 negative breast carcinomas (p=0.002). No significant difference in immunostaining for c-erbB-2 protein in the two groups was found (p=0.15), or for the coexpression of p53/c-erbB-2 (p=0.19). The significantly lower expression of p53 and p21 proteins in HPV 16 positive than in HPV 16 negative breast carcinomas supports the hypothesis of inactivation and degradation of wild-type p53 proteins by HPV 16 E6 and that p53 mutation is not necessary for transformation in the HPV 16 positive cases.     

MDM2和p53蛋白在膀胱癌中过度表达的意义

目的 观察膀胱癌中ＭＤＭ２和ｐ５３蛋白的表达状况及意义。方法 用免疫组化检测７０例原发性膀胱移行细胞癌（ＴＣＣ）中ＭＤＭ２和ｐ５３蛋白的过度表达情况。结果 ＭＤＭ２核免疫阳笥４４．２９％（３１／７０）,３２例（４５．７１％）ｐ５３核染色体阳性,两者共同阳性９例。ＭＤＭ２表达是膀胱癌的早期表现,ｐ５３蛋白与ＭＤＭ２相反,两者呈负相关。结论 ＭＤＭ２和ｐ５３蛋白是膀胱癌发生发展的两个早晚基因事件。     

Combined effects of p53, p21, and pRb expression in the progression of bladder transitional cell carcinoma.

PURPOSE: To determine the combined effects of p53, p21, and pRb alterations in predicting the progression of bladder transitional cell carcinoma. PATIENTS AND METHODS: p53, p21, and pRb expression was examined immunohistochemically on archival radical cystectomy samples from 164 patients with invasive or high-grade recurrent superficial transitional cell carcinoma (TCC; lymph node-negative, 117 patients; lymph node-positive, 47 patients). Median follow-up was 8.6 years. Based on percentage of nuclear reactivity, p53 was considered as wild-type (0% to 10%) or altered (>10%); p21 was scored as wild-type (>10%) or altered (<10%); and pRb status was considered wild-type (1% to 50%) or altered (0% or >50%). RESULTS: As individual determinants, the p53, p21, and pRb status were independent predictors of time to recurrence (P<.001, P<.001, and P<.001, respectively), and overall survival (P<.001, P=.002, and P=.001, respectively). By examining these determinants in combination, patients were categorized as group I (no alteration in any determinant, 47 patients), group II (any one determinant altered, 51 patients), group III (any two determinants altered, 42 patients), and group IV (all three determinants altered, 24 patients). The 5-year recurrence rates in these groups were 23%, 32%, 57%, and 93%, respectively (log-rank P<.001), and the 5-year survival rates were 70%, 58%, 33%, and 8%, respectively (log-rank P<.001). After stratifying by stage, the number of altered proteins remained significantly associated with time to recurrence and overall survival. CONCLUSION: This study suggests that alterations in p53, p21, and pRb act in cooperative or synergistic ways to promote bladder cancer progression. Examining these determinants in combination provides additional information above the use of a single determinant alone.     

Combined p21 and p53 overexpression predict improved survival in muscle-invasive bladder cancer treated by radical radiotherapy

Purpose: The prognostic value of p21 and p53 expression was evaluated for patients with muscle-invasive bladder cancer treated by radical radiotherapy.

Methods and Materials: Sixty-eight paraffin-embedded sections from surgically resected tumors taken prior to irradiation were immunostained for p21 and p53.

Results: Nuclear staining for p21 and p53 was demonstrated in 32/68 (47%) and 46/68 (68%) tumors, respectively. There was no correlation between p21 and p53 immunopositivity in this group (r = 0.067, p = 0.56). Patients were stratified into four distinct groups depending on staining for p21 and p53: p21+p53+, p21+p53−, p21−p53+, and p21−p53−. Patients with p21+p53+ tumors had the best prognosis with a 3-year survival of 82% compared to 12% for p21−p53+ tumors (p = 0.0031), 29% for p21+p53− tumors (p = 0.0108); and 45% for p21−p53− tumors (p = 0.0375). The p21+p53+ group also demonstrated significantly improved survival when a combined analysis was performed of p21−p53+, p21−p53−, and p21+p53− tumors (3-year SURVIVAL = 30%, p = 0.0062). In a multivariate model, p21+p53+ tumors (p = 0.0108, relative risk [RR] = 5.18) and complete/partial response (p = 0.0019, RR = 3.76) were the only independent predictors of improved survival.

Conclusions: With muscle-invasive bladder tumors treated by radical radiotherapy, stratification for p21 and p53 identifies distinct prognostic groups, with p21+p53+ tumors being associated with the best survival and p21−p53+ the worst.     

Combined p21WAF1/CIP1 and p53 overexpression predict improved survival in muscle-invasive bladder cancer treated by radical radiotherapy

Purpose: The prognostic value of p21 and p53 expression was evaluated for patients with muscle-invasive bladder cancer treated by radical radiotherapy.Methods and Materials: Sixty-eight paraffin-embedded sections from surgically resected tumors taken prior to irradiation were immunostained for p21 and p53.Results: Nuclear staining for p21 and p53 was demonstrated in 32/68 (47%) and 46/68 (68%) tumors, respectively. There was no correlation between p21 and p53 immunopositivity in this group (r = 0.067, p = 0.56). Patients were stratified into four distinct groups depending on staining for p21 and p53: p21+p53+, p21+p53−, p21−p53+, and p21−p53−. Patients with p21+p53+ tumors had the best prognosis with a 3-year survival of 82% compared to 12% for p21−p53+ tumors (p = 0.0031), 29% for p21+p53− tumors (p = 0.0108); and 45% for p21−p53− tumors (p = 0.0375). The p21+p53+ group also demonstrated significantly improved survival when a combined analysis was performed of p21−p53+, p21−p53−, and p21+p53− tumors (3-year survival = 30%, p = 0.0062). In a multivariate model, p21+p53+ tumors (p = 0.0108, relative risk [RR] = 5.18) and complete/partial response (p = 0.0019, RR = 3.76) were the only independent predictors of improved survival.Conclusions: With muscle-invasive bladder tumors treated by radical radiotherapy, stratification for p21 and p53 identifies distinct prognostic groups, with p21+p53+ tumors being associated with the best survival and p21−p53+ the worst.     

Loss of p21Waf1 expression is a strong predictor of reduced survival in primary superficial bladder cancers.

p21Waf1 is a downstream effector of p53 and belongs to the Cip1/Kip1 family of cyclin-dependent kinase inhibitors. Thus, it is a potential tumor suppressor gene and likely plays an important role in tumor development. Moreover, reduced expression of p21Waf1 has been reported to have prognostic value in several human malignancies. In this study, we evaluated the prognostic value of p21Waf1 in bladder cancer compared with other clinicopathological features and with p27Kip1 and p53 expression. A total of 96 superficial (pTa-1) human bladder carcinomas were immunohistochemically stained for p21Waf1 protein expression. Positive p21Waf1 staining (> or =5% positive nuclei) was observed in 68 of the 96 (71%) tumors. p21Waf1 expression was neither associated with tumor stage (P = 0.9) nor with tumor grade (P = 0.18) but was significantly associated with both p53 protein expression (> or =20% positive nuclei; P = 0.007) and with p53 gene mutations (P = 0.017). A significant correlation was also observed between positivity for p21Waf1 and high (>50% positive cells) p27Kip1 expression (P = 0.04). With regard to prognosis, patients whose tumors showed absence of p21Waf1 staining displayed a significantly shorter overall survival (P = 0.01 by log-rank test). However, p21Waf1 expression did not correlate with disease-free survival (P = 0.15 by log-rank test). On a multivariate analysis that also included p53 and p27Kip1 expression, negative p21Waf1 staining was an independent predictor of reduced overall survival (P = 0.004; relative risk, 5.32), stronger than age and tumor stage. These data indicate that expression of p21Waf1 protein strongly correlates with survival and might represent a useful prognostic marker in primary superficial bladder carcinomas.     

p53 and p21 Expression levels predict organ preservation and survival in invasive bladder carcinoma treated with a combined-modality approach

BACKGROUND: The purpose of the current study was to evaluate the expression levels of p53, p21 and pRB as predictors of for long-term organ preservation and survival in patients with bladder carcinoma who were treated with bladder-sparing intent using a combined-modality approach. METHODS: Tumor samples from 82 consecutive patients with localized invasive bladder carcinoma treated on 3 different bladder-sparing studies were examined for p53, p21, and pRB expression by immunohistochemical methods. Treatment consisted of transurethral resection, platinum-based neoadjuvant chemotherapy, and, according to response, either radiotherapy or radical cystectomy. The median follow-up duration was 55 months. RESULTS: Positive immunoreactivity for p53, p21, and pRB was observed in 47%, 52%, and 67% of patients, respectively. Positive p53 immunoreactivity and positive p21 immunoreactivity were independent predictors of decreased survival with bladder preservation (P = 0.02 and P = 0.02, respectively) and disease-free survival (DFS; P = 0.005 and P = 0.009, respectively) in a multivariate analysis adjusting for clinical stage, ureteral obstruction, and age. Regarding overall survival (OS), p53 overexpression was associated with poor outcome (P = 0.03), whereas the association of poor outcome with p21 expression did not reach statistical significance (P = 0.07). No association between pRB immunoreactivity and outcome was found. When the combined expression of p53 and p21 was assessed, the positive expression of both markers was a strong and unfavorable prognostic factor for survival with bladder preservation (P = 0.006), DFS (P = 0.003), and OS (P = 0.02). CONCLUSIONS: Expression levels of p53 and p21, especially when simultaneously assessed, exhibit independent predictive value for long-term bladder preservation and survival in patients with bladder carcinoma treated with combined-modality therapy. These determinations could be useful in the selection of candidates for bladder-preserving treatment.     

Prognostic factors in transitional cell cancer of the bladder: an emerging role for Bcl-2 and p53.

BACKGROUND AND PURPOSE: In a recent study on patients with transitional cell cancer of the bladder treated with curative radiotherapy following TUR-T, we demonstrated that a low apoptotic index and p53 positivity were associated with poor local control. The purpose of this study was to assess the prognostic significance of additional markers implicated in regulation of cell cycle and apoptosis. PATIENTS AND METHODS: Bcl-2, Bax and p21 positivity were detected immunohistochemically on paraffin-embedded pre-treatment biopsies from 83 patients with invasive transitional cell cancer (TCC) of the bladder, treated with radiotherapy. In addition, markers determined in an earlier analysis, i.e.: p53, apoptotic index, cyclin D1, retinoblastoma protein and Ki-67 were included in the multivariate analysis. A stepwise proportional hazard analysis was performed, adjusting for classic prognostic factors (T-stage, grade, multifocality and macroscopic completeness of the TUR). Positivity was defined as >10% of tumor cells staining positive for Bcl-2, Bax and p21, and >20% for p53. RESULTS: Bcl-2 positivity was found in 63%, Bax was positive in 52% and p21 in 55% of cases. In the PH analysis Bcl-2 positivity was found to be related to poor local control (36 vs. 72% at 3 years; P=0.003), as well as to shorter disease-specific survival (74 vs. 94% at 3 years; P=0.017). Evidence for an adverse effect of p53 positivity was also found (local control: 32 vs. 69% at 3 years;P=0.037, disease-specific survival: 76 vs. 92% at 3 years; P=0.043). In an additional PH analysis, we found poor local control rates for bladder cancers with combined Bcl-2 and p53 positivity (17 vs. 65% at 3 years; P=0.0017), and lower disease specific survival (60 vs. 92%; P=0.0024), disease-free survival (7 vs.35%, P=0.0023) and overall survival (39 vs. 80%; P=0.0018). CONCLUSION: This study provides evidence for a poor outcome in patients treated with radiotherapy for TCC of the bladder expressing both Bcl-2 and p53. This relationship was found for local control and disease-free, disease-specific and overall survival.     

Increased expression levels of p53 correlate with good response to cisplatin-based chemotherapy in non-small cell lung cancer

In order to determine whether expression of the tumor suppressor gene p53 in non-small cell lung cancer (NSCLC) correlates with chemotherapeutic response, resected tumors from 18 patients with recurrent lung cancer who had undergone complete resection and received chemotherapy after the initial tumor recurrence were subjected to p53 immunostaining. Histological examination of the resected tumors revealed 11 adenocarcinomas, 6 squamous cell carcinomas and one adenosquamous cell carcinoma. Group 1 was 50% (n=9) p53-immunopositive. All patients received cisplatin-based chemotherapy after recurrence. No patient in group 1 achieved response to chemotherapy whereas 2 and 3 in group 2 achieved complete and partial responses, respectively. The chemotherapy response rate of group 2 (56%) was significantly higher than that of group 1 (0%, p=0.009). The times to reoccurrence after tumor resection of group 2 was significantly better than that of group 1 (log-rank p=0.019, Wilcoxon p=0.042), and survival after chemotherapy of group 2 was also significantly better than that of group 1 (log-rank p=0.023, Wilcoxon p=0.034). It is suggested that high p53 expression levels in tumors correlate with both good response to cisplatin-based chemotherapy and good survival of patients with advanced NSCLC.     

An immunohistochemical study of p21 and p53 expression in primary node-positive breast carcinoma.

AIMS: p21, an inhibitor of cyclin-dependent kinase, is involved in the p53 pathway of growth control. Its expression has been linked to cellular differentiation. It has been implicated in p53-mediated growth arrest following DNA damage and in terminally differentiated cells. This study analysed p21 and p53 expression, in a series of node-positive patients with breast carcinoma and examined histopathological parameters of the tumour and the prognostic implications of p21 and p53 expression. METHODS: One hundred and five consecutive patients with node-positive disease and at least 3 years follow-up were identified. Sections were stained for p53 and p21 using monoclonal antibodies. Results were expressed as percentage positive cells, and over 20% considered positive for p53 and over 10% considered for p21. RESULTS: p21 was overexpressed (>10% of cells positive) in 65% of patients and p53 was overexpressed (>20% of cells positive in 68%. The mean (SEM) level of p21 staining was 5.7(0.8)% and was 54.9(4.0)% for p53. There was no correlation between p21 and p53 expression (r=0.071 P=0.5). There were no significant differences in demographic criteria between patients that were p21 positive or negative and p53 positive or negative. There were no significant differences in tumour type, grade or stage between the groups. p21 expression did not have prognostic significance; however, p53 positivity was associated with a worse prognosis, which remained when controlled for stage. CONCLUSIONS: This study demonstrated p21 overexpression in 65% of patients with node-positive breast carcinoma. Levels did not correlate with p53 status and unlike p53 failed to have prognostic significance. Copyright Harcourt Publishers Limited.