Overexpression of p53 associated with tumor angiogenesis, tumor cell proliferation, and prognosis in gastric carcinoma

Mutations in the p53 gene seem to be the most common genetic change in human malignancies. Recently, it was reported that p53 mutation was significantly associated with prognosis in various cancers. In this study, we investigated the correlation between p53 overexpression and prognosis of gastric carcinoma using immunohistochemical staining with an anti-p53 antibody. Although there was no significant association between p53 status and various clinicopathologic factors, prognosis of patients with p53-positive tumors was significantly worse than of those with p53-negative: tumors. Both microvessel count (MVC; the mean number of microvessels in the five areas of highest vascular density at 200x magnification) and PCNA labeling index (PCNA LI; percentage of positive cells per more than 500 tumor cells) were significantly higher in p53-positive tumors than in p53-negative tumors. In summary, it is suggested that p53 overexpression is closely associated with tumor angiogenesis, tumor cell proliferation and prognosis of gastric carcinoma.     

P53 mutations in primary tumors and subsequent liver metastases are related to survival in patients with colorectal carcinoma who undergo liver resection

BACKGROUND: The appearance of p53 mutations in colorectal carcinoma was determined, independent of differentiation and tumor stage of the primary tumors, in relation to the survival of patients who were scheduled to undergo liver resection. METHODS: Tumor material was analyzed for p53 mutations in primary colorectal tumors and subsequent liver metastases from 41 consecutive patients who were scheduled to undergo surgical liver resection. DNA sequencing and immunohistochemical staining of p53 protein within tumor nuclei were performed. RESULTS: Primary tumors displayed p53 mutations within exons 5-9 in 41% of patients. No mutations were found in exons 4, 10, or 11. Forty-one percent of metastatic lesions had the same single mutation that was found in the primary tumor, whereas 11% of metastatic lesions had one additional mutation within exons 5-9; 22% had mutations only in their liver metastases, whereas corresponding primary tumors displayed wild-type p53. None of the patients had mutated p53 in their primary tumor and wild type in their metastases. Survival after undergoing liver resection was correlated negatively (P < 0.05-0.01) with Duke Stages A-D classification of the primary tumors, tumor differentiation, and radicality (> 0.7-0.8 mm) of resected liver metastases. CONCLUSIONS: The presence of p53 mutations in patients with metastatic lesions was related significantly (P < 0.003) to better survival after the patients underwent liver resection compared with patients with wild type p53 in their metastatic lesions. This finding was not related to covariates, such as Duke classification, tumor differentiation, type of liver metastasis, or metastatic radicality during resections. Explanations for this unexpected finding remain unclear, although the authors speculate that occult tumor cells with p53 mutations may be less responsive to growth factor(s) exposure during hepatic regeneration after resection.     

Comparative study of various biological parameters,including expression of survivin,between primary and metastatic human colonic adenocarcinomas

BACKGROUND: Hepatic metastasis of colorectal carcinomas is the most important factor in prognosis. We examined the level of apoptosis and proliferation, the expression of survivin, bcl-2, p53 and intratumoral microvessel density (IMVD) in paired tissue specimens of primary human colon tumors and hepatic metastases and determined the molecular biological changes of the tumor cells in liver metastasis. MATERIALS AND METHODS: We examined, immunohistochemically, the level of apoptosis and proliferation, the expression of survivin, bcl-2 p53 and intratumoral microvessel density in 37 paired tissue specimens of primary colon tumors and hepatic metastases. RESULTS: The mean apoptotic index (AI) was 0.60+/-0.45 for the primary colon tumors and 1.22+/-0.73 for the hepatic metastases. The mean proliferative index (PI) was 37.4+/-15.8 for the primary colon tumors and 29.4+/-14.1 for the hepatic metastases. Significantly higher AI and lower PI were observed in the hepatic metastases as compared to the primary colon tumor (p<0.0001 and p=0.0049, respectively). The mean-weighted survivin score was 4.32+/-2.78 for primary colon carcinomas, and 1.54+/-1.77 for the hepatic metastases. The mean-weighted bcl-2 score was 2.62+/-2.62 for the primary colon carcinomas and 0.81+/-1.56 for the hepatic metastases. There were significantly decreased scores of immunostaining for both survivin and bcl-2 in the hepatic metastases as compared to the primary carcinomas (p<0.0001 and p<0.0002, respectively). Nuclear accumulation of p53 was demonstrated in 25 cases (67.6%) of the primary carcinomas and 24.cases (64.9%) of the hepatic metastases, without significant differences. The IMVD was 89.9+/-37.5 for primary colon tumors, while it was 55.1+/-32.5 for hepatic metastases. A statistically significant decrease in the IMVD was observed in the hepatic metastases as compared to the primary colon tumors (p<0.0001). CONCLUSION: These data suggest that the tissue kinetics of colorectal carcinoma cells in hepatic metastases are biologically quite different from those of primary tumors, probably because of co-operative effects of both internal (AI, survivin, bcl-2) and external (IMVD) regulation factors.     

Morphologic analysis of microvessels in colorectal tumors with respect to the formation of liver metastases.

BACKGROUND AND OBJECTIVES: Overexpression of VEGF and proliferation of microvessels are strongly related to liver metastases, however, morphologic analyses of microvessels in liver metastases have not been reported. The purpose of the present study was to examine the correlation between liver metastases and the diameters of microvessel lumens in the tumor tissue. METHODS: Fifty-nine patients with liver metastases from colorectal cancers and 112 patients who underwent curative colorectal resection and survived without any recurrence were reviewed. Microvessel density (MVD) and the diameters of the lumens of individual microvessels were assessed. RESULTS: There was a significant difference in terms of the mean MVD of primary tumors between patients with liver metastases and those without liver metastases. The numbers of patients with liver metastases who had microvessels 100-200 microm in diameter and microvessels more than 200 microm in diameter were significantly greater than patients without liver metastases. Microvessels with lumens more than 100 microm in diameter were not detected in the liver metastatic lesion. CONCLUSION: Large microvessels in the primary tumor favor intravasation of cancer cells.     

Mutations in the p53 suppressor gene do not correlate with C-k-ras oncogene mutations in colorectal-cancer

Mutations in the p53 tumor suppressor gene have been analyzed in 196 colorectal tumors previously analyzed for mutations at codons 12 and 13 of the c-K-ras and N-ras oncogenes by a combination of Single Strand Conformation Polymorphism (SSCP) and Cycle Sequencing (CS) using total cellular RNA. Mutations were detected in 3 of 21 adenomas, 84 of 149 primary carcinomas, and 11 of 18 hepatic metastases. Over half of the tumors were homozygous for the mutant p53 allele at the mRNA level. Although deletions were detected in 5 tumors, missense mutations were the most frequent. The spectrum of 63 point mutations was heterogeneous, with all possible nucleotide substitutions ocurring at least once. No correlation was found between the spectrum of p53 gene mutations and the age, sex, race of the cancer patients or the anatomical localization of the tumors, although mutations were significantly more frequent in tumors of the distal colon. Mutations in the p53 gene did not correlate with mutations in the c-K-ras gene, indicating that colorectal cancer can develop through pathways independent not only of the presence of mutations in any of these genes but also of their cooperation.     

Angiogenesis and p53 expression in the colorectal adenoma-carcinoma sequence

Angiogenesis, the formation of new vessels, is essential for tumor growth and metastasis. Mutations of p53 tumor suppressor gene are frequent and play an important role in colorectal oncogenesis. A role of p53 as an angiogenesis inhibitor has also been proposed. We evaluated angiogenesis and p53 expression in 16 hyperplastic polyps, 35 solitary tubular and tubulovillous adenomas, and 47 cases of sporadic colorectal carcinomas arising on the basis of preexisting adenomas, with standard immunohistochemical techniques. The mean microvessel density (MVD) in carcinomas was significantly higher compared with the respective adenomatous part of the same tumor (27.9 vs. 7; P=0.0001). Linear regression analysis of MVD between cancerous and adenomatous areas showed a significant correlation (P = 0.0001, r = 0.56), raising the possibility that carcinomas arising from better vascularized adenomas might show increased vascularity. The MVD was significantly higher in stage C compared with stage A cases (P=0.04). p53 positivity was detected in 26 of 47 cancerous (55%) and in 14 of 47 adenomatous areas (30%; P = 0.0002). All carcinomas arising from p53-positive adenomas were also p53 positive. p53 positivity associated with a higher MVD in adenomas (P = 0.02), but not in carcinomas (P = 0.78). We conclude that angiogenesis and p53 play a critical role in colorectal neoplasia, and the process of malignant transformation in tumors arising from highly angiogenic adenomas, particularly those carrying p53 mutations, is accelerated with rapid tumor progression from stage to stage, indicating a more aggressive tumor phenotype.     

VEGF and bFGF expression and microvessel density of maxillary sinus squamous cell carcinoma in relation to p53 status, spontaneous apoptosis and prognosis

We have previously reported that p53 mutations, loss of bax expression or decreased spontaneous tumor apoptosis were associated with poorer prognoses in maxillary sinus squamous cell carcinoma (SCC)(Cancer 94: 1968-1980, 2002). In the present study, we analyzed tumor angiogenesis monitored by expression of vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF) and tumor microvessel density, in correlation with p53 status, spontaneous apoptosis or disease prognosis in the same group of 70 maxillary sinus SCC patients. Tumor biopsy specimens obtained prior to initiation of treatment were examined for expression of VEGF and bFGF and tumor microvessel density using immunohistological methods. Average vessel density (AVD) (range: 3-75; median: 25) and maximum vessel density (MVD) (range: 4-125; median: 53) were assessed by the number of microvessels stained with anti-CD31 mAb in tumor lesions. VEGF was expressed in 35 (50%) of 70 patients and bFGF was in 43 (61%). Patients with VEGF expression showed significantly higher levels of MVD than those without VEGF expression (57 vs. 38; P=0.019). The VEGF expression was observed more frequently in patients with p53 overexpression and/or mutation than in those with normal p53 status (P=0.048). The MVD inversely correlated with the apoptotic index (AI) defined as the number of single stranded (ss)-DNA-positive cells per 1000 tumor cells (r= -0.23; P=0.022). Patients with neck lymph node and/or distant metastases after surgery showed significantly higher levels of MVD than patients without any metastasis (64 vs. 42; P=0.048). Low histological effectiveness of radiochemotherapy correlated with bFGF expression (P=0.0059). To clarify actual prognostic factors for maxillary sinus SCC, we selected 57 patients treated uniformly with preoperative radiochemotherapy followed by maxillectomy. Kaplan-Meier analysis showed that survival was significantly worse in patients with high MVD (> or =80) than in those with low MVD (<80) (P=0.042). These data suggest that the VEGF expression in association with the p53 overexpression and/or mutations may cause increased microvascularity, decreased spontaneous apoptosis or metastases, while the bFGF expression may be associated with resistance to radiochemotherapy, thereby resulting in poorer prognoses in maxillary sinus SCC. VEGF and bFGF expression and tumor microvessel density in tumor lesions were analyzed in 70 patients with maxillary sinus squamous cell carcinoma. The VEGF expression dependent of p53 overexpression and/or mutations was associated with angiogenesis, decreased spontaneous tumor apoptosis and metastases, while the bFGF expression was associated with resistance to radiochemotherapy, resulting in poor prognosis.     

Association of p53 mutations,microvessel density and neoangiogenesis in pairs of colorectal cancers and corresponding liver metastases

p53 suppressor gene mutations are a well known step which occurs in the late stages of the complex tumourigenesis of colorectal cancer. A deregulation of p53 protein function may be associated with increased neovascularization and aggressive tumour growth. In vitro studies have shown that these genetic alterations cause a loss of wild-type p53-induced anti-angiogenetic control and could possibly induce expression of the neoangiogenic vascular endothelial growth factor (VEGF). Therefore, this in vivo study was performed to assess p53 mutations, i.e. hot spots in exons 4-9, in primary colorectal cancers and in corresponding liver metastases in order to test whether there is an association between p53 mutated tumours with increased microvessel density (MVD) and VEGF overexpression. Twenty-two tissue samples taken from primary colorectal cancers and the corresponding liver metastases were immediately snap-frozen in liquid nitrogen and fixed in formaldehyde. After DNA extraction exons 4-9 were amplified and directly sequenced. Cryostat sections were stained immunohistochemically using antibodies against VEGF, CD34, and p53 protein. A modified semiquantitative Weidner score and interactive computerized image analysis was used to assess MVD. Overexpression of immunohistochemically detected p53 protein was found in 7 of the 11 primary tumours and liver metastases (64%). Sequencing showed 3 out of 11 primary tumours (27%) and 5 out of 11 liver metastases (46%) to have p53 point or frameshift mutations; these samples tested immunohistochemically positive for p53 protein. Two p53 mutations in samples of liver metastases were not detectable in the corresponding primaries. We detected one frameshift mutation in exon 4 that has not yet been described in the literature. Tumour samples with p53 mutations and increased VEGF immunoreactivity were associated with higher MVD (p<0.01 and p<0.05, respectively). However, there was no association detected immunohistochemically between p53 and MVD as well as p53 mutations and VEGF overexpression. Our data demonstrate specific genetic alterations in the coding regions of p53 suppressor gene in both primary colorectal cancers and corresponding liver metastases, these alterations are associated with an increase in MVD, but not in VEGF overexpression. In addition, a novel frameshift mutation in both colorectal cancer and metastasis is described.     

Angiogenic interactions of vascular endothelial growth factor, of thymidine phosphorylase, and of p53 protein expression in locally advanced gastric cancer

The assessment of the angiogenic profile of tumors may become an important tool as a guide for the inclusion of novel drugs and molecular therapies into the standard chemoradiotherapy policy. Several studies have shown the prognostic importance of microvessel density (MVD) and of angiogenic factor expression in operable gastric cancer. In the present study we investigated, with immunohistochemistry the MVD, the expression of vascular endothelial growth factor (VEGF) and of thymidine phosphorylase (TP) expression, as well as the nuclear expression of p53 protein, in a series of patients with locally advanced inoperable gastric cancer. A strong association of VEGF with TP expression was noted (P = 0.005), and tumors coexpressing these factors had a statistically higher MVD (P = 0.0001). Nuclear p53 accumulation was also related to a high MVD (P = 0.004), and this was independent of VEGF or TP expression. Microvessel density showed a bell-shaped association with prognosis; cases with an intermediate MVD exhibit a favorable outcome (P < 0.05). A trend of nuclear TP expression to define a group of patients with poorer prognosis was noted (P = 0.06), while none of the remaining variables showed any significant association. The immunostaining results allowed the grouping of the angiogenic profile in four major categories: 1) highly vascularized tumors with VEGF and/or TP expression (about 36% of cases); 2) highly angiogenic tumors with p53 nuclear accumulation and low VEGF/TP expression (7% of cases); 3) poorly vascularized tumor with low VEGF/TP and negative nuclear p53 staining (32% of cases); 4) poorly vascularized tumors with TP expression (7% of cases). Specific therapies targeting hypoxia, VEGF, or TP expression as well as p53 gene therapy have entered clinical experimentation or are already available for clinical use. Using the suggested markers more than 80% of locally advanced gastric carcinomas can be grouped in different categories according to their angiogenic profile. Such a categorization may be useful for phase III trials on novel therapies targeting the major angiogenesis-related features studied here.     

p53、血管内皮生长因子在大肠癌组织中的表达与血管生成

目的　探讨p53、血管内皮生长因子 (VEGF)在大肠癌组织中的表达及其与血管生成的关系。方法　利用免疫组化SABC法 ,对 1 0 6例大肠癌组织及 2 0例正常大肠组织中的 p53、VEGF的表达及微血管密度 (MVD)进行研究。 结果　p53、VEGF的表达与肿瘤的分化程度及Dukes分期无明显相关性 (P >0 .0 5 )。p53表达阳性或VEGF表达阳性的大肠癌组织MVD明显高于p53表达阴性 (P <0 .0 1 )或VEGF表达阴性者 (P <0 .0 1 )。p53表达阳性的大肠癌组织中VEGF的表达阳性率显著高于 p53表达阴性者 (P <0 .0 1 )。结论　p53、VEGF在大肠癌的发生和发展中起着重要作用 ,可反映大肠癌的恶性程度和进展情况并作为预后的指标 ,p53作用的发挥是通过上调VEGF的表达水平来实现的     

The TP53 colorectal cancer international collaborative study on the prognostic and predictive significance of p53 mutation: influence of tumor site, type of mutation, and adjuvant treatment.

PURPOSE: The aims of the TP53 Colorectal Cancer (CRC) International Collaborative Study were to evaluate the possible associations between specific TP53 mutations and tumor site, and to evaluate the prognostic and predictive significance of these mutations in different site, stage, and treatment subgroups. PATIENTS AND METHODS: A total of 3,583 CRC patients from 25 different research groups in 17 countries were recruited to the study. Patients were divided into three groups according to site of the primary tumor. TP53 mutational analyses spanned exons 4 to 8. RESULTS: TP53 mutations were found in 34% of the proximal colon tumors and in 45% of the distal colon and rectal tumors. They were associated with lymphatic invasion in proximal tumors. In distal colon tumors, deletions causing loss of amino acids were associated with worse survival. In proximal colon tumors, mutations in exon 5 showed a trend toward statistical significance (P < .05) when overall survival was considered. Dukes' C tumors with wild-type TP53 and those with mutated TP53 (proximal tumors) showed significantly better prognosis when treated with adjuvant chemotherapy. CONCLUSION: Analysis of TP53 mutations from a large cohort of CRC patients has identified tumor site, type of mutation, and adjuvant treatment as important factors in determining the prognostic significance of this genetic alteration.     

大肠癌原发灶和肝转移灶p53变异及蛋白表达

目的 了解Ｐ５３及其蛋白在大肠癌发生、转移过程中的动态变化。方法Ｐ５３基因外显子５－９以ＤＧＧＥ及自动ＤＮＡ序列分析来检测,Ｐ５３蛋白表达以免疫组化方法检测。结果 ３４例中２１例呈Ｐ５３变异,占６１．８％,其中５例仅在肝转移灶发现Ｐ５３变异,其余均为原发灶、转移灶生的变异。另有２例原发灶即有Ｐ５３变异者,在转移灶出现了新增加的变异。在３７处变异中,２７和为错义突变占７３．０％;６处为无义突变占１６     

The relationship of molecular markers of p53 function and angiogenesis to prognosis of stage I epithelial ovarian cancer.

PURPOSE: Multiple angiogenic factors may influence tumor progression and metastasis. Several are modified by the p53 gene. We sought to identify molecular markers for high-risk stage I epithelial ovarian cancers. EXPERIMENTAL DESIGN: Seventy-seven consecutive stage I epithelial ovarian cancers were evaluated for p53, CD31 microvessel density, thrombospondin-1, vascular endothelial growth factor (VEGF), p21 immunohistochemical staining, and p53 gene mutations. Molecular marker impact upon disease-specific survival, disease recurrence, and distant recurrence was evaluated with Cox regression. RESULTS: There were 12 deaths from disease. Twelve of the 77 tumors contained p53 mutations-10 missense and 3 null (one tumor had two mutations). Fesddration Internationale des Gynaecologistes et Obstetristes substage (IA/IB versus IC; P < 0.001) and VEGF staining (P = 0.02) were significant in bivariate models with relationship to disease-specific survival. Stage (P = 0.0004), grade (P = 0.008), histology (P = 0.0025), p53 dysfunction (positive stain and/or mutation; P = 0.048), and microvessel density (P = 0.04) were significant in bivariate models with relationship to time to recurrence. In multivariate analyses among stage IC patients, failure to receive chemotherapy and microvessel density were associated with disease-specific survival, time to recurrence, and time to distant recurrence with hazard ratios of 4.8 to 44.1. CONCLUSIONS: The p53-dependent molecular markers of angiogenesis are of limited utility in developing a clinical strategy for postoperative management of stage I ovarian carcinoma. Microvessel density impacts survival and metastasis for high-risk stage IC disease. Adjuvant chemotherapy is necessary, but not sufficient, for cure of high-risk stage I epithelial ovarian cancers.     

Selective loss of codon 72 proline p53 and frequent mutational inactivation of the retained arginine allele in colorectal cancer

According to recent reports, some cancer types exhibit nonrandom allele loss at codon 72 in exon 4 of the p53 gene [coding for proline (72Pro) or arginine (72Arg)]. To clarify this phenomenon for colorectal cancer and to find out if this preferential loss might have any functional significance, p53 loss of heterozygosity (LOH) and p53 mutations were investigated in a group of 61 colorectal cancers and 28 liver metastases, and were correlated with clinicopathologic factors. A comparison of a patient's blood codon 72 status with a healthy control group did not reveal an enhanced risk of developing colorectal tumors for one of the two isoforms. p53-LOH and p53 mutations were found in 62.2% and 39.4% of primary tumors, respectively, and in 57.9% and 25% of hepatic metastases, respectively. In 14 heterozygous cases showing exon 4-LOH, only the 72Pro allele was lost and the retained 72Arg was preferentially mutated. In general, p53 mutations were significantly associated with the 72Arg tumor status (P < .001). Distal tumors showed allelic losses of the p53 gene more commonly than proximal tumors (P = .054). The prevalence of 72Arg increased in frequency with higher Dukes stage (P = .056). We suggest that either the preferential loss of 72Pro or the mutation of the 72Arg in colorectal cancer and hepatic metastases is associated with malignant potential and might reflect carcinogenic exposure, particularly in the distal part of the large intestines.     

p53 Mutations and protein overexpression in primary colorectal cancer and its liver metastasis

Although there have already been many studiesreported about p53 statIJs on primary colorectal cancerand / or hepatic metastases,t'. 2] we have not found anyrepoft that compares p53 status between primary andmetastatic lesions in each patient on an individual level.34 patieflts with colorectal cancer and liver metastaseswere chosen for this study. P53 status in Primary and livermetastatic tllmor lesions of every individual wereinvestigated, in order to understand that p53 gene statusduring tumo…     

High incidence of protein-truncating mutations of the p53 gene in liver metastases of colorectal carcinomas

To clarify the significance of p53 mutations in liver metastasis of colorectal carcinogenesis, the characteristics of p53 mutations from 51 liver metastases and 76 primary invasive carcinomas without liver metastasis (Dukes' A, B and C) were compared. The frequency of tumors with p53 mutations was 61% (31 out of 51) in the liver metastases, and 51% (39 out of 76) in the primary carcinomas without liver metastasis. Approximately 90% of the informative cases having p53 mutation showed 17pLOH. Mutations detected within exons 4-10 of the p53 gene included missense, nonsense, frameshift, inframe deletion, and inframe insertion mutations. Out of the tumors with p53 mutations, we found that the percentage of tumors with protein-truncating mutations (nonsense and frameshift mutations) was extremely higher in liver metastases (16 out of 31, 52%) than in primary carcinomas without liver metastasis (5 out of 39, 13%) (P=0.0005). The present results suggest that protein-truncating mutations of the p53 gene are more relevant than missense mutations as one of the prognostic factors in liver metastasis of colorectal carcinomas.     

Characterization of p53 mutations in colorectal liver metastases and correlation with clinical parameters.

The presence and type of mutations of the p53 tumor suppressor gene were determined in 40 patients undergoing curative hepatic resection for metastatic colorectal carcinoma. This represents the largest series in the literature on the screening of p53 mutations for liver metastases. The analysis was performed in exons 5-9 by denaturing gradient gel electrophoresis followed by direct sequencing. Forty-five percent of tumors showed mutation in p53, and this was observed only in exons 5-8. Mutations at codon positions 167, 196, 204, 213, 245, 281, 282, 286, and 306; deletion of codon 251 and of the first nucleotide of codon 252; and Leu residue (CTC) insertion downstream codon 252 are reported for the first time in colorectal liver metastasis. Mutations at codon positions 163, 248, and 273 have been reported previously. Correlation of p53 status with clinical parameters showed that patients with mutated p53 had a statistically higher number of lesions when compared with patients with wild-type p53 (P<0.050). In particular, of patients with mutated p53, 41% had three or more metastases compared with 14% of patients with wild-type p53. Synchronous metastases were present in 70% of the patients with p53 mutations and in only 29% of patients with wild-type p53 (P<0.025). In addition, patients with p53 mutations are more likely to develop recurrence (73%) compared with patients with wild-type p53 (33%; P<0.001). Other factors considered, including preoperative carcinoembryonic antigen level, bilobar distribution, and size of the lesion(s), did not show significant correlation with p53 status. These results suggest that p53 status might be an important prognostic indicator to predict the pattern and likelihood of treatment failure after hepatic resection.     

Mutations in TP53 are a prognostic factor in colorectal hepatic metastases undergoing surgical resection

The aim of this study was to analyze the prognostic value of TP53 mutations in a consecutive series of patients with hepatic metastases (HMs) from colorectal cancer undergoing surgical resection. Ninety-one patients with liver metastases from colorectal carcinoma were included. Mutational analysis of TP53, exons 4-10, was performed by single-strand conformation polymorphism and sequencing. P53 and P21 protein immunostaining was assessed. Multivariate Cox models were adjusted for gender, number of metastasis, resection margin, presence of TP53 mutations and chemotherapy treatment. Forty-six of 91 (50.05%) metastases showed mutations in TP53, observed mainly in exons 5-8, although 14.3% (n = 13) were located in exons 9 and 10. Forty percent (n = 22) were protein-truncating mutations. TP53 status associated with multiple (> or =3) metastases (65.6%, P = 0.033), advanced primary tumor Dukes' stage (P = 0.011) and younger age (<57 years old, P = 0.03). Presence of mutation associated with poor prognosis in univariate (P = 0.017) and multivariate Cox model [hazard ratio (HR) = 1.80, 95% confidence interval (CI) = 1.07-3.06, P = 0.028]. Prognostic value was maintained in patients undergoing radical resection (R0 series, n = 79, P = 0.014). Mutation associated with a worse outcome in chemotherapy-treated patients (HR = 2.54, 95% CI = 1.12-5.75, P = 0.026). The combination of > or =3 metastases and TP53 mutation identified a subset of patients with very poor prognosis (P = 0.009). P53 and P21 protein immunostaining did not show correlation with survival. TP53 mutational status seems to be an important prognostic factor in patients undergoing surgical resection of colorectal cancer HMs.     

Somatic TP53 mutations are relatively rare among adrenocortical cancers with the frequent 17p13 loss of heterozygosity.

PURPOSE: Allelic losses [loss of heterozygosity (LOH)] at the 17p13 locus are frequent (85%) in adrenocortical cancers. The tumor suppressor gene TP53 is located at 17p13. The aim of the study was to determine the frequency of TP53 somatic inactivating mutations in adrenocortical tumors with 17p13 LOH and their clinico-biological correlations. EXPERIMENTAL DESIGN: TP53 somatic mutations, intragenic LOH (VNTR1 marker), and p53 overexpression were studied in 36 adrenocortical tumors with 17p13 LOH determined by Southern blot. RESULTS: TP53 mutations were detected in 33% of the tumors, and VNTR1 LOH was present in 44% of the cases and did not always correlate with the presence of a TP53 mutation. Only the TP53-mutant tumors exhibit a strong nuclear immunoreactivity. TP53-mutant tumors were significantly larger than wild-type TP53 tumors (median tumor weight: 640 versus 185 g; P=0.02), were associated with a more advanced stage of tumor progression (MacFarlane stage IV; P=0.01), and had a shorter disease-free survival (P=0.03). CONCLUSIONS: The finding that only a minority of adrenocortical tumors with 17p13 LOH had either a VNTR1 LOH or a TP53 mutation indicates that TP53 might not be the only or major tumor suppressor gene at 17p13 involved in adrenocortical cancer progression. We suggest that a genetic instability of the 17p13 region, occurring early in adrenocortical cancer development, involves various genes located in this region. TP53 might be only one of them, and its alteration by the occurrence of inactivating mutation is associated with the development of more aggressive tumors.