Activated Akt as an indicator of prognosis in gastric cancer

The immunohistochemical expression of phosphorylated (activated) Akt (pAkt) in 50 advanced gastric carcinomas has been analyzed and the results correlated with age, sex, location in the stomach, histotype, stage, survival, mitotic and apoptotic index, some cell cycle regulators (cyclin D1, cyclin E, p34/cdc2, p27/kip1), and cell proliferation. There was a statistically significant direct correlation between pAkt expression (both cytoplasmatic and nuclear) and depth of infiltration of the tumor, number of infiltrated lymph nodes and p34/cdc2 expression, and between prevalently nuclear pAkt and cyclin D1 and cyclin E. Conversely, there was a significant inverse correlation between nuclear pAkt and apoptotic index and between cytoplasmatic and nuclear pAkt and patient survival. No correlation was found between pAkt and sex, age, tumor location, histotype, mitotic index, and cell proliferation. These findings suggest that pAkt may be considered an indicator of tumor progression and patient survival in gastric cancer.     

Expression of heart-type fatty acid-binding protein in human gastric carcinoma and its association with tumor aggressiveness, metastasis and poor prognosis.

OBJECTIVE: Fatty acid-binding proteins (FABPs) are involved in lipid metabolism by intracellular transport of long-chain fatty acids. Heart-type (H-) FABP has been reported to inhibit cell growth and induce cell differentiation, but to our knowledge the significance of H-FABP expression in human gastric carcinoma has not been elucidated. The aim of the current study was to examine the expression of H-FABP and its relation to clinicopathologic parameters and fatty acid synthase (FAS) status of gastric carcinoma, since gastric cancer shows increased expression of FAS. METHODS: Immunohistochemistry with anti-H-FABP antibody was performed in 669 gastric carcinomas and 60 tubular adenomas of the stomach. H-FABP-positive and H-FABP-negative carcinomas were analyzed for their clinicopathologic characteristics and FAS status. RESULTS: None of the adenomas expressed H-FABP, whereas 127 of 669 carcinomas (19.0%) were positive for the protein. H-FABP positivity was associated with the depth of invasion (p <0.0001), vascular invasion (p <0.0001), lymph node metastasis (p <0.0001), hepatic metastasis (p=0.0011), stage of the carcinoma (p <0.0001) and FAS status of the carcinoma (p=0.0476). A higher survival rate was noted in H-FABP-negative cases compared with H-FABP-positive cases (p=0.0004). CONCLUSIONS: A subset of human gastric carcinoma expresses H-FABP and its expression is associated with FAS status, disease progression, tumor aggressiveness and poor patient survival.     

Proximity ligation assays for isoform-specific Akt activation in breast cancer identify activated Akt1 as a driver of progression

The PI3K/Akt signal transduction pathway plays an important role in cancer progression and cell survival. Akt activation is associated with poor outcome in endocrine-treated breast cancer, whereas high levels of cytoplasmic Akt2 are associated with an improved overall survival. Proximity ligation assays (PLAs) were used to determine quantitative expression levels of isoform-specific activation (phosphorylation) of Akt1 and Akt2 in formalin-fixed, paraffin-embedded cell lines and breast cancer tumour tissues in situ. PLAs demonstrated a range of expression in breast cancer samples for total pAkt1 and pAkt2. High levels of pAkt1 were associated with reduced DRFS (HR: 1.45, 95% CI 1.14-1.83, p = 0.002) and OS (HR: 1.42, 95% CI 1.10-1.83, p = 0.007). When PLA results were combined, patients that had high levels of pAkt1 only had a significantly decreased DRFS (HR: 1.92, 95% CI 1.34-2.76, p = 0.005) and OS (HR: 1.94, 95% CI 1.32-2.86, p = 0.008) compared to other patients. Using PLAs to discriminate activation of Akt1 versus Akt2 suggests that Akt1 drives progression in early breast cancers. In cases where both Akt1/Akt2 are activated, Akt2 may act to reverse this effect. Using PLAs, we have measured activation of Akt1 and Akt2 proteins separately in situ in FFPE breast cancer samples.     

Reduced expression of the cell-cycle inhibitor p27Kip1 is associated with progression and lymph node metastasis of gastric carcinoma

AIMS: p27Kip1 (p27), a cyclin-dependent kinase inhibitor, plays an important role as inhibiting the progression of the cell cycle. Decreased expression of p27 is associated with high histological grade and aggressiveness of several human tumours. We aimed to evaluate the role of p27 in the progression and metastasis of gastric carcinoma. METHODS AND RESULTS: We analysed the expression of p27 in 67 primary gastric carcinomas and 31 lymph node metastases by immunohistochemistry. Reduced expression of p27 was found more frequently in advanced gastric cancer (40.9%) than in early gastric cancer (15.6%) (P < 0.001). Decreased p27 expression correlated with large tumour size, high histological grade, lymphatic invasion, advanced stage, deep invasion, lymph node metastasis and recurrence. The expression of p27 showed an inverse correlation with the Ki67 labelling index. There was a significant reduction of p27 expression in metastatic tumour cells in lymph nodes (mean positive cells: 3. 7%) when compared to the corresponding primary gastric carcinomas (mean positive cells: 8.1%) (P = 0.008). CONCLUSIONS: Alterations of p27 expression may play an important role in the progression and metastasis to lymph node of tumour cells in human gastric carcinoma.     

Decreased xanthine oxidoreductase is a predictor of poor prognosis in early-stage gastric cancer

BACKGROUND: Xanthine oxidoreductase (XOR) is a key enzyme in the degradation of DNA, RNA and high-energy phosphates. About half of the patients with breast cancer have a decrease in XOR expression. Patients with breast cancer with unfavourable prognosis are independently identified by the loss of XOR. AIM: To assess the clinical relevance of XOR expression in gastric cancer. METHODS: XOR levels were studied by immunohistochemistry in tissue microarray specimens of 337 patients with gastric cancer and the relation between XOR expression and a series of clinicopathological variables, as well as disease-specific survival, was assessed. RESULTS: XOR was moderately decreased in 41% and was undetectable in another 14% of the tumours compared with the corresponding normal tissue. Decreased XOR was associated with advanced stage, deep tumour penetration, diffusely spread tumour location, positive lymph node status, large tumour size, non-curative disease, cellular aneuploidy, high S-phase fraction and high cyclooxygenase-2 expression, but not with p53 expression or Borrmann classification. Down regulation of XOR was associated with unfavourable outcome, and the cumulative 5-year gastric cancer-specific survival in patients with strong XOR expression was 47%, compared with 22% in those with moderate to negative expression (p<0.001). This was also true in patients with stage I-II (p = 0.01) and lymph node-negative (p = 0.02) disease, as well as in patients with smaller (< or =5 cm) tumours (p = 0.02). CONCLUSION: XOR expression in gastric cancer may be a new marker for a more aggressive gastric cancer biology, similar to that previously reported for breast cancer.     

Clinicopathological correlations of mTOR and pAkt expression in non-small cell lung cancer

The Akt/mammalian target of rapamycin (mTOR) pathway is up-regulated in many human cancers, and agents targeting the mTOR pathway are in various stages of clinical development and application. Expression of pAkt and mTOR was studied by immunohistochemical analysis of 574 surgically resected non-small cell lung cancer (NSCLC) specimens on a tissue microarray. The results were correlated with clinicopathological features. Expression of mTOR showed a strong correlation with the expression of pAkt (p?相似文献   

High-level expression of fatty acid synthase in human prostate cancer tissues is linked to activation and nuclear localization of Akt/PKB

Many human epithelial cancers, particularly those with a poor prognosis, express high levels of fatty acid synthase (FAS), a key metabolic enzyme linked to the synthesis of membrane phospholipids in cancer cells. In view of the recent finding that in the human prostate cancer cell line LNCaP, overexpression of FAS can be largely attributed to constitutive activation of the phosphatidylinositol-3 (PI3) kinase/Akt kinase pathway, the activation status of the Akt pathway, and whether this activation coincides with increased FAS expression, was examined in clinical prostate cancer tissues. Using well-preserved frozen prostatic needle biopsies and a sensitive Envision detection technique, S473-phosphorylated Akt (pAkt) was found in 11/23 low-grade prostatic intraepithelial neoplasia (PIN) lesions, in all (36/36) high-grade PINs, and in all (86/86) invasive carcinomas. Non-neoplastic tissues were negative. Interestingly, in low-grade PINs and low-grade carcinomas, pAkt was mainly cytoplasmic or membrane-bound and was associated with moderate elevation of FAS expression. In 24/36 high-grade PINs and 82/88 invasive carcinomas, pAkt was found at least partly in the nucleus. Greater nuclear pAkt staining, and higher FAS expression, correlated with a higher Gleason score. In the light of previous findings that pAkt plays a causative role in the overexpression of FAS in cancer cells in culture, these data strongly suggest that high-level expression of FAS in prostate cancer tissues is linked to phosphorylation and nuclear accumulation of Akt.     

Expression of PRL-3 phosphatase in human gastric carcinomas: close correlation with invasion and metastasis.

OBJECTIVE: High expression of PRL-3, a protein tyrosine phosphatase, has been reported to be associated with metastasis of colorectal carcinoma. The aim of this study is to investigate the significance of PRL-3 expression in tumor progression and metastasis of gastric carcinoma. METHODS: The levels of PRL-3 mRNA expression in 8 gastric cancer cell lines were examined by RT-PCR. Ninety-four human gastric carcinomas and 54 matched lymph node metastases were employed in this study. The expression of PRL-3 was detected by immunohistochemistry and the relationship with clinicopathological parameters was analyzed. RESULTS: The expression of PRL-3 mRNA was clearly detected in 7 of 8 gastric cancer cell lines (87.5%) by RT-PCR. In tumor samples, PRL-3 expression was detected in 68% of primary gastric carcinoma (with nodal metastasis 81.5%, without nodal metastasis 50%; p = 0.004). The incidence of PRL-3 expression in lymph node metastasis was significantly higher than that in primary gastric cancers (p < 0.001). Moreover, PRL-3 expression was closely associated with lymphatic invasion (p = 0.002), extent of lymph node metastasis (p = 0.002) and tumor stage (p = 0.045). CONCLUSIONS: These results strongly suggest that PRL-3 expression may play a significant role in invasion and metastasis of gastric carcinoma. PRL-3 might be a novel molecular marker for aggressive gastric cancer.     

Nuclear beta catenin as a potential prognostic and diagnostic marker in patients with colorectal cancer from Hong Kong.

AIMS: To study the expression of nuclear beta catenin in patients with colorectal cancer, colorectal adenoma, and colorectal polyps to elucidate its role in carcinogenesis, and its potential for prognosis and diagnosis. METHODS: The expression of nuclear beta catenin was studied by immunohistochemistry using paraffin wax embedded specimens. Sixty specimens each of colorectal carcinoma, colorectal adenoma, colorectal polyp, and normal colorectal specimens were analysed. The potential for prognosis was assessed by correlating nuclear beta catenin expression in 60 and 75 patients with colorectal cancer with lymph node metastasis and survival, respectively. The diagnostic capacity was explored by comparing nuclear beta catenin expression in 60 patients with colorectal cancer with other cytokeratin 20 (CK20) positive adenocarcinomas, namely: 30 colonic mucinous adenocarcinomas, 30 gastric adenocarcinomas, 27 pancreatic adenocarcinomas, and 12 ovarian mucinous adenocarcinomas. RESULTS: Nuclear beta catenin expression was highly associated with progression of colorectal tissue from normal epithelial tissue, polyps, adenomas, to carcinomas (r = 0.875; p < 0.0001). Nineteen patients with colorectal adenoma who subsequently developed colorectal carcinoma had higher nuclear beta catenin expression than those with colorectal adenomas alone (p < 0.0001). Moreover, those patients with colorectal cancer and high nuclear beta catenin expression had a higher incidence of lymph node metastasis (chi(2) = 16.99; p < 0.005) and shorter overall survival (p < 0.0001). Finally, nuclear beta catenin expression in colorectal adenocarcinomas was significantly higher than in other CK20 positive adenocarcinomas. CONCLUSIONS: Nuclear beta catenin expression is a potential prognostic factor in patients with colorectal cancer, and together with CK20, it could be used to identify colorectal carcinoma in the Hong Kong population.     

The prognostic significance of COX-2 and survivin expression in ovarian cancer

We investigated the prognostic significance of cyclooxygenase-2 (COX-2) and survivin in ovarian carcinoma. Imprint smears were obtained from 100 ovarian carcinoma specimens and were studied immunocytochemically for the expression of COX-2 and survivin. The results were correlated with several clinicopathological parameters, including 5-year survival. Increased COX-2 staining pattern correlated with a non-mucinous histological type (p=0.008), increased stage (p<0.0001), high histological grade (p<0.0001), and reduced survival rates (p<0.00001). Survivin expression was strongly associated with increased stage (p<0.0001), increased histological grade (p<0.0001), and reduced survival (p<0.00001). Elevated survivin expression also correlated significantly with pre-menopausal status (p=0.033). In addition, COX-2 and survivin staining patterns correlated strongly with one another (p<0.0001). However, on multivariate analysis, an independent prognostic value was found only for tumor stage and grade. The findings of our study indicate that the increased expression of COX-2 and survivin in ovarian cancer is associated with one another and with several adverse clinicopathologic parameters, including reduced survival, thus suggesting a role of these molecules in disease progression. Further investigations of the exact prognostic and therapeutic implications of COX-2 and survivin expression are strongly warranted.     

Akt activation and localisation correlate with tumour invasion and oncogene expression in thyroid cancer

Introduction: Akt activation is involved in the pathogenesis of inherited thyroid cancer in Cowden's syndrome and in sporadic thyroid cancers. In cell culture, Akt regulates thyroid cell growth and survival; but recent data suggest that Akt also regulates cell motility in non-thyroid cell lines. We therefore sought to evaluate the role of Akt in thyroid cancer progression.

Methods: We evaluated 46 thyroid cancer, 20 thyroid follicular adenoma, and adjacent normal tissues samples by immunohistochemistry for activated Akt (pAkt), Akt 1, 2, and 3, and p27 expression. Immunoblots were performed in 14 samples.

Results: Akt activation was identified in 10/10 follicular cancers, 26/26 papillary cancers, and 2/10 follicular variant of papillary cancers, but in only 4/66 normal tissue samples and 2/10 typical benign follicular adenomas. Immunoactive pAkt was greatest in regions of capsular invasion; and was localised to the nucleus in follicular cancers and the cytoplasm in papillary cancers, except for invasive regions of papillary cancers where it localised to both compartments. Immunoactive Akt 1, but not Akt 2 or Akt 3, correlated with pAkt localisation, and nuclear pAkt was associated with cytoplasmic expression of p27. In vitro studies using human thyroid cancer cells demonstrated that nuclear translocation of Akt 1 and pAkt were associated with cytoplasmic p27 and cell invasion and migration. Cell migration and the localisation of Akt 1, pAkt, and p27 were inhibited by PI3 kinase, but not MEK inhibition.

Discussion: These data suggest an important role for nuclear activation of Akt 1 in thyroid cancer progression.

     

E-cadherin和FOXO3a在胃癌组织和细胞中表达的关系

目的:探讨上皮钙黏素(E-cadherin)和叉头框蛋白O3a(FOXO3a)在胃癌组织和细胞中表达的关系及意义。方法:应用免疫组织化学法检测53例胃癌组织及对应癌旁组织中E-cadherin和FOXO3a的表达情况,分析两者的表达水平及与临床病理参数的关系。构建E-cadherin过表达的胃癌稳转细胞株AGS,免疫细胞化学法检测E-cadherin及FOXO3a蛋白表达,Western blot法检测细胞中E-cadherin、FOXO3a、Akt、Bcl-2和Bax的蛋白表达,CCK-8法检测细胞活力。结果:胃癌组织中E-cadherin和FOXO3a的阳性率较对应癌旁组织均显著降低(P0.05)。E-cadherin表达与胃癌分化程度和TNM分期显著相关(P0.05),与年龄、性别、肿瘤部位、T分期及淋巴结转移无显著相关。FOXO3a表达与胃癌分化程度显著相关(P0.05),与年龄、性别、部位、TNM分期、T期及淋巴结转移无显著相关。胃癌组织中E-cadherin与FOXO3a表达存在显著正相关(r=0.376,P=0.003)。E-cadherin过表达后,胃癌AGS细胞活力显著下降,细胞中FOXO3a和Bax表达显著升高,Akt表达显著下降。结论:E-cadherin与FOXO3a共同参与胃癌的发生发展,E-cadherin可能通过调节Akt/FOXO3a信号传导影响胃癌细胞活力。     

PKIB expression strongly correlated with phosphorylated Akt expression in breast cancers and also with triple-negative breast cancer subtype

The cAMP-dependent protein kinase inhibitor-?? (PKIB) is presumed to be one of the regulatory factors controlling the cAMP-dependent protein kinase A signaling pathway. The aim of this study was to investigate the frequency and patterns of PKIB overexpression in human breast cancer. We also examined the relationship between PKIB and phosphorylated Akt (pAkt) expression in the tumors. Using immunohistochemical techniques, we examined the expression of PKIB, ER, PR, HER2, and pAkt in 148 primary human breast carcinomas. We then analyzed the relationships between PKIB expression and that of pAkt, ER, PR, and HER2, as well as between PKIB expression and various clinicopathological characteristics. We assessed 64 and 27 cases, respectively, as positive for either PKIB or pAkt expression; 20 cases were positive for both PKIB and pAkt. We observed a significant positive correlation between the expression of PKIB and that of pAkt (P = 0.006). We showed by immunohistochemical analyses that PKIB expression was positively correlated with triplenegative breast cancers (P = 0.0004). These findings provide evidence for PKIB overexpression associated with pAkt expression. Furthermore, PKIB expression was strongly correlated with triple-negative breast cancer, suggesting that PKIB expression might contribute to the tumor behavior and development of breast cancer.     

Slug is overexpressed in gastric carcinomas and may act synergistically with SIP1 and Snail in the down-regulation of E-cadherin

Epithelial-mesenchymal transition (EMT) involving down-regulation of E-cadherin is known to play an important role in tumour progression. The aim of our study was to investigate the mRNA expression of two EMT regulators-Slug and E12/E47-in primary human gastric carcinomas and to compare this with the expression of E-cadherin and other EMT regulators (Snail, Twist, and SIP1). We studied a series of 59 gastric carcinomas by real-time quantitative RT-PCR in formalin-fixed and paraffin-embedded tissues. Thirty-four cases (58%) showed Slug up-regulation in the tumour; reduced or negative expression of E-cadherin was present in 24 of these (71%, p<0.0001). Twenty-one cases (36%) showed E12/E47 up-regulation that was not significantly associated with E-cadherin down-regulation (p=0.5734). Slug up-regulation accompanied by E-cadherin down-regulation correlated with the presence of distant metastases (p=0.0029) and with advanced pTNM stages (p=0.0424). A statistically significant association was found between Slug up-regulation and the expression of SIP1 in intestinal (p=0.0014) and Snail in diffuse (p=0.0067) carcinomas. We present the first study integrating the analysis of several EMT regulators in primary gastric carcinomas and conclude that Slug up-regulation is associated with E-cadherin down-regulation in diffuse and intestinal-type gastric carcinoma, and that this effect could be complemented by the presence of other EMT regulators.     

Limited value of KAI1/CD82 protein expression as a prognostic marker in human gastric cancer

The cell surface glycoprotein KAI1/CD82 suppresses tumor growth and metastasis in animal models. This study aimed to evaluate the prognostic relevance of KAI1/CD82 protein expression in human gastric cancer. Primary gastric carcinomas (n=271) with a mean clinical follow-up time of 48 months were immunostained using the monoclonal anti-KAI1/CD82 antibody G2. Staining was evaluated as negative versus positive for statistical analysis. KAI1/CD82 immunoreactivity was absent in 103/271 (38%) cases. There was a trend towards KAI1/CD82 negativity in poorly differentiated cases (p=0.0679). Moreover, KAI1/CD82-negative carcinomas were associated with a higher pT status (p=0.0222), metastatic lymph node involvement (p=0.0018) and a higher clinical tumor stage (p=0.0050). The median overall survival times of KAI1/CD82-negative and KAI1/CD82-positive gastric carcinomas were 20 and 37 months, respectively (p=0.2305). These results are in line with the proposed function of KAI1/CD82 as a suppressor of tumor growth and metastasis. However, these data suggest that KAI1/CD82, as detected by immunohistochemistry, is of limited value as a prognostic marker for gastric cancer in routine histological workup.     

Clinicopathological significance and survival influence of p53 protein expression in gastric carcinoma

AIMS: Mutations in the gene coding for p53 protein are among the most frequent genetic alterations observed in human cancers. The relevance and biological significance of p53 expression in gastric carcinoma are far from being fully established. The aim of our study was to evaluate the influence of p53 detected by immunohistochemistry in the clinicopathological behaviour of a series of gastric carcinoma cases. METHODS AND RESULTS: Samples from 163 patients treated by gastric resection for gastric carcinoma between 1988 and 1995 were used. Surgical specimens were evaluated for the presence of p53 protein detected by immunohistochemistry with a monoclonal antibody. Cases were classified as positive or negative for p53. Several clinicopathological parameters and c-erb B-2 expression were analysed in the same series and compared with the expression of p53. Cumulative survival was evaluated using univariate analysis and Cox model regression. p53 expression was identified in 41 carcinomas (25.2%) and was significantly associated with venous invasion (P = 0.049), lymph node metastases (P = 0.01) and c-erb B-2 expression (P = 0.003). All the parameters except gender, tumour size and Laurén's classification influenced survival on univariate analysis. p53 expression correlated with overall survival (P = 0.006) and survival in the subgroup of patients with intestinal type carcinoma (P = 0.04). In the subgroup of patients with carcinomas not expressing c-erb B-2, p53 expression significantly influenced cumulative survival (P = 0.02). CONCLUSIONS: p53 expression is associated with the aggressive biological behaviour of gastric carcinomas and is related to cumulative survival.     

乳腺癌Akt的表达及其临床意义

目的 本研究试图分析乳腺癌Akt的表达状况,并了解与其它有关生物学标记物的关系,为乳腺癌的治疗探索新的方法提供初步的理论基础.方法 采用免疫组化EnVision两步法检测110例有随访资料的浸润性乳腺癌中pAkt和Akt的表达情况.结果 乳腺癌pAkt和Akt2的阳性定位于肿瘤细胞的胞质或胞核.其pAkt和Akt2的阳性率分别为50%(55/110)和35.5%(39/110).Akt2阳性的患者死亡率高于阴性患者,而pAkt阳性患者的淋巴结转移率及死亡率均高于阴性患者,差异具有统计学显著意义(P<0.01).pAkt和Akt2均与患者的c-erbB-2的阳性表达率呈正相关.但二者与乳腺癌的癌基因p53、凋亡相关基因bcl-2、ER及PR的表达和肿瘤的组织学分级及患者年龄均无相关性.结论 Akt的表达与c-erbB-2的过表达以及与患者较差的预后具有统计学意义的显著关联性,提示Akt的表达情况可能作为评估乳腺癌患者预后的参考指标之一;也表明尤其当患者出现对内分泌治疗抵抗时,摧毁PKB/Akt这一细胞内信号转导途径是否将更有利于乳腺癌的治疗值得进一步的研究.     

p21WAF1 expression in invasive breast cancer and its association with p53, AP-2, cell proliferation,and prognosis

AIMS: To evaluate the expression and prognostic relevance of p21(WAF1) in breast cancer and to investigate its association with p53, activator protein 2 (AP-2), and cell proliferation (as assessed by Ki-67 expression). METHODS: p21(WAF1) expression was analysed immunohistochemically in a large prospective, consecutive series of 420 patients with breast cancer diagnosed and treated between 1990 and 1995 at Kuopio University Hospital, Kuopio, Finland. Inter-relations between p21(WAF1) expression and p53, AP-2, and Ki-67 were evaluated. The expression of p21(WAF1) was also compared with clinicopathological parameters and the patients' survival. RESULTS: In general, nuclear p21(WAF1) expression was low in carcinomas (median, 2.5%; range, 0-70%). Expression was lowest in lobular carcinomas (chi(2) = 7.4; p = 0.025). p21(WAF1) positive tumours were more often p53 positive (chi(2) = 4.2; p = 0.041) but expression of p21(WAF1) did not correlate with AP-2 expression or Ki-67 in the whole patient group. In addition, the combined expression of p21 and p53 was not associated with AP-2 expression. High nuclear p21(WAF1) positivity (n = 160; 38%) was associated with poor differentiation (chi(2) = 8.1; p = 0.017). In the univariate analyses, p21(WAF1) expression had no prognostic value for predicting breast cancer related survival (BCRS) or recurrence free survival (RFS) in the whole patient group or in the subgroups investigated. However, in postmenopausal patients with lymph node metastases, and oestrogen receptor (ER) and/or progesterone receptor (PR) positive tumours, high p21(WAF1) expression predicted response to adjuvant hormonal treatment with antioestrogens. In the univariate analysis, the significant factors for predicting BCRS were Ki-67 expression, stage, lymph node status, histological grade, ER and PR status, and those for RFS were Ki-67 expression, stage, and lymph node status. In the multivariate analysis, the independent predictors of shorter BCRS were high cell proliferation activity measured by Ki-67 expression (p < 0.001), advanced stage (p < 0.001), and poor differentiation (p = 0.048). Shorter RFS was independently predicted by high cell proliferative activity (p < 0.001) and advanced stage (p < 0.001). CONCLUSIONS: The regulation of p21(WAF1) seems to occur independently of p53 or AP-2 and analysing p21(WAF1) expression provided no prognostic information for patients with breast cancer.