p53 mutation and protein accumulation during multistage human esophageal carcinogenesis.

Preinvasive lesions of squamous cell carcinoma are well defined morphologically and provide a model for multistage carcinogenesis. Since alterations in the p53 tumor suppressor gene occur frequently in invasive esophageal squamous cell carcinoma, we examined a set of preinvasive lesions to investigate the timing of p53 mutation. Surgically resected tissues from nine patients with esophageal squamous cell carcinoma contained precursor lesions which had not yet invaded normal tissues. Immunohistochemistry showed high levels of p53 protein in both preinvasive lesions and invasive carcinomas in six cases; sequence analysis of all invasive tumors identified p53 missense mutations in two cases. Preinvasive lesions from both tumors with mutations plus one wild-type tumor were microdissected and sequenced. In one patient there were different mutations in the invasive carcinoma (codon 282, CGGarg > TGGtrp) and a preinvasive lesion (codon 272, GTGval > T/GTGleu/val). In a second case, an invasive carcinoma had a mutation in codon 175 (CGCarg > CAChis), and adjacent preinvasive lesions contained a wild-type sequence. A carcinoma and preinvasive lesion from the third case contained high levels of protein and a wild-type DNA sequence. Therefore, p53 mutation may precede invasion in esophageal carcinogenesis, and multifocal esophageal neoplasms may arise from independent clones of transformed cells. The timing of p53 protein accumulation is favorable for an intermediate biomarker in multistage esophageal carcinogenesis.     

p53 mutations in childhood thyroid tumors from Belarus and in theyroid tumors without radiation history

Mutations in the p53 tumour-suppressor gene (exons 5–8) were investigated in 31 Belarussian childhood thyroid tumours (24 cases of papillary thyroid carcinoma, 3 benign tumours and 2 cases each of thyroiditis and goiter); 33 thyroid tumours from juveniles and adults without radiation exposures (25 carcinomas of various histological types, including 11 papillary carcinomas and 8 adenomas) and 6 tumours from adults (4 papillary carcinomas, 1 adenoma, 1 goiter) served as controls. The mutational spectrum of p53 differed greatly between the childhood thyroid carcinomas from Belarus and the control groups. In the control groups of 29 malignant thyroid tumours, 7 different mutations were detected on exons 5–8, none of which occurred among the 15 papillary carcinomas in this group. Five mutations were found in tissue samples of the 24 childhood papillary carcinomas, and they were all the same p53 point mutation (CGA |iO CGG) on codon 213 of exon 6. To determine whether this mutation is simply a polymorphism or whether it is specific to the tumour cells, laser-assisted microdissection was applied to collect various areas of tumorous and non-tumorous cells (10–20 cells per sample) from each paraffin-embedded tissue section of 8 of the papillary thyroid carcinomas. Using PCR-SSCP and sequence analysis on these cells, the very same p53 mutation on codon 213 was detected in various microdissected tumour samples of 2 cases, but it was not found in any microdissected non-tumorous sample. The exclusive occurrence of this p53 mutation in selective microdissected samples of tumour cells, even as homozygous mutation in 1 case, reflects a distinct tumour heterogeneity within papillary childhood thyroid carcinomas. Int. J. Cancer 73:802–807, 1997. © 1997 Wiley-Liss, Inc.     

Role of p53 gene mutations in human esophageal carcinogenesis: results from immunohistochemical and mutation analyses of carcinomas and nearby non-cancerous lesions

In order to characterize p53 alterations in esophageal cancer and to study their roles in carcinogenesis, we performed gene mutation and immunohistochemical analysis on 43 surgically resected human esophageal specimens, which contain squamous cell carcinoma (SCC) and adjacent non-cancerous lesions, from a high-incidence area of Linzhou in Henan, China. A newly developed immunohisto-selective sequencing (IHSS) method was used to enrich the p53 immunostain-positive cells for mutation analysis. p53 gene mutations were detected in 30 out of 43 (70%) SCC cases. Among 29 SCC cases that were stained positive for p53 protein, 25 (86%) were found to contain p53 mutations. In five cases of SCC with homogeneous p53 staining, the same mutation was observed in samples taken from four different positions of each tumor. In a well differentiated cancer nest, p53 mutation was detected in only the peripheral p53-positive cells. In tumor areas with heterogeneous p53 staining, either the area stained positive for p53 had an additional mutation to the negatively stained area or both areas lacked any detectable p53 mutation. In the p53-positive non-cancerous lesions adjacent to cancer, p53 mutations were detected in seven out of 16 (47%) samples with basal cell hyperplasia (BCH), eight out of 12 (67%) samples with dysplasia (DYS), and six out of seven (86%) samples with carcinoma in situ (CIS). All mutations found in lesions with DYS and CIS were the same as those in the nearby SCC. In seven cases of BCH containing mutations, only three had the same mutations as the nearby SCC. The results suggest that p53 mutation is an early event in esophageal carcinogenesis occurring in most of the DYS and CIS lesions, and cells with such mutations will progress to carcinoma, whereas the role of p53 mutations in BCH is less clear.     

Serial histologic evaluation of multiple primary squamous cell carcinomas of the esophagus

A review of data on 205 patients with esophageal squamous cell carcinoma who underwent subtotal esophagectomy revealed 30 cases (14.6%) and 32 lesions with multiple primary squamous cell carcinomas. The incidence of this multiplicity was 11.7% and 25.6% in those with and without preoperative irradiation treatment, respectively. Among the 32 second lesions, there were 17 intraepithelial carcinomas, eight restricted to the mucosa, five invading the submucosa, one invading down to the proper muscular layer, and one involving the entire thickness of the esophageal wall. These second lesions were in the relatively early stage. Moreover, incidence of the coexistence of intraepithelial carcinoma contiguous to the main lesion was 42.1% and 100.0% in those with multiple cancers, with and without preoperative irradiation, respectively. The values were 7.6% and 53.1% in patients with a solitary carcinoma, respectively. These findings show the close relationship between multiplicity and intraepithelial carcinoma contiguous to the main lesion, and support the concept of multicentric or field carcinogenesis of esophageal squamous cell carcinoma.     

An associated concomitant early multiple esophageal carcinoma and gastric carcinoma

Presented is the case of a 71-year-old female with an associated, concomitant early multiple esophageal carcinoma and a gastric carcinoma. An esophageal endoscopy revealed a reddish region in the upper and middle esophagus. This lesion, in part, remained unstained by lugol. Further, three lesions were observed at the upper and middle portions of the esophagus in a resected specimen, and the macroscopic diagnosis was 0-II c, These lesions were histologically diagnosed as being moderately differentiated squamous cell carcinomas, 5 x 15 mm, 2 x 5 mm, and, 3 x 5 mm in size. Furthermore, a lesion in the cardia was found superimposed on the esophageal cancer, and diagnosed as being an adenocarcinoma (II b), 10 x 15 mm in size. In the literature, reports of a concomitant association of an early esophageal carcinoma and a gastric carcinoma amount to 19 cases in Japan, our case being the twentieth case. In formatively, our case was found to display a multiple carcinoma in the esophagus.     

Genetic progression and divergence in superficial esophageal squamous cell carcinoma by loss of heterozygosity analysis

Esophageal squamous cell carcinoma (SCC) is one of the most common fatal carcinomas worldwide and has some of the most malignant characteristics among gastrointestinal tumors. Although a high frequency of loss of heterozygosity (LOH) for various genes has been observed in esophageal SCCs, these findings do not provide any information regarding the genetic pathways that may underlie the development and progression of this type of tumor. To clarify the temporal and topographic pathways in the genetic evolution of esophageal SCC, we microdissected multiple foci from superficial mucosal invasive foci of tumors. We then carried out LOH analyses of the microdissected neoplastic foci. Sixteen superficial esophageal SCCs were examined. Three to six carcinoma foci from each superficial esophageal SCC were individually microdissected. We used 12 oligonucleotide primer pairs specific for the microsatellite markers for which frequent LOH in esophageal SCC has been reported. All tumors exhibited LOH of at least three microsatellite loci. A frequent homogeneous LOH pattern was detected for TP53 (60%), D16S518 (43%) and D3S1234 (29%), suggesting that the loss of these alleles is an early event in the development of esophageal SCC. A heterogeneous LOH pattern was detected for D13S325 (87%), D10S559 (73%), D3S1568 (58%), D3S1234 (57%) and D3S1621 (56%), suggesting that the loss of these alleles is a late event in the development of esophageal SCC. All tumors showed the LOH pattern of single clonal neoplasms with genetic progression and divergence. In conclusion, by extensive sampling of SCC lesions with microdissection and LOH analysis of multiple chromosomal loci, we successfully demonstrated dynamic and successive accumulation of genetic alterations in early SCC.     

p53 in esophageal adenocarcinoma: a critical reassessment of mutation frequency and identification of 72Arg as the dominant allele

p53 alterations have been implicated in the progression of Barrett's esophagus to esophageal adenocarcinoma. However, the wide range of reported p53 alteration frequencies in esophageal adenocarcinoma makes using p53 as a marker of malignant transformation of Barrett's esophagus problematic. To determine the utility of p53 in Barrett's esophagus monitoring, the frequency of p53 alteration was critically reassessed using esophagectomy specimens of 40 cases of esophageal adenocarcinoma, including 10 with Barrett's esophagus and high-grade dysplasia, 8 with low-grade dysplasia and 7 with no dysplasia. DNA was extracted from tumor cells isolated by laser capture microdissection to maximize the assay sensitivity and mutations in exons 4-8 of p53 were determined by PCR direct sequencing. Mutations in p53 were identified in 75% (30/40) of the esophageal adenocarcinoma. p53 protein overexpression, detected by immunohistochemistry, was found in 58% (23/40) of the esophageal adenocarcinoma, 60% (6/10) of Barrett's esophagus with high-grade dysplasia, 12% (1/8) of Barrett's esophagus with low-grade dysplasia, and 0% of Barrett's esophagus without dysplasia. In addition to the mutations, a predominance of the 72Arg allele (89% homozygous) was found over the 72Pro allele in this series. p53 mutation frequency in this study was higher than reported in most of the literature and DNA sequencing detected more p53 alterations than immunohistochemical staining. However, p53 appeared to be a late marker in the neoplastic transformation, and no p53 change was found in approximately 25% of the adenocarcinoma. We concluded that p53 is insufficient as a single marker for Barrett's esophagus monitoring but may be useful as part of a panel due to its high specificity.     

High frequency and heterogeneous distribution of p53 mutations in aflatoxin B1-induced mouse lung tumors.

Inactivation of the p53 tumor suppressor gene is one of the most frequent genetic alterations observed in human lung cancers. However, p53 mutations are more rarely detected in chemically induced mouse lung tumors. In this study, 62 female AC3F1 (A/J x C3H/HeJ) mice were treated with aflatoxin B1 (AFB1; 150 mg/kg i.p. divided into 24 doses over 8 weeks). At 6-14 months after dosing, mice were killed, and tumors were collected. A total of 71 AFB1-induced lung tumors were examined for overexpression of p53 protein by immunohistochemical staining. Positive nuclear p53 staining was observed in 79% of the AFB1-induced tumors, but the pattern was highly heterogeneous. In approximately 73% of the positively stained tumors, fewer than 5% of cells demonstrated positive staining; in the other 27%, between 10% and 60% of the cells stained positively, with staining localized to the periphery of the tumors in many cases. Single-strand conformational polymorphism analysis of the evolutionarily conserved regions of the p53 gene (exons 5-8) from AFB1-induced whole lung tumor DNA revealed banding patterns consistent with point mutations in 20 of 76 (26%) tumors, with 85% of the mutations in exon 7 and 15% of the mutations in exon 6. Identification of point mutations could not be confirmed by direct sequence analysis because bands representing putative mutations appeared only weakly on autoradiograms. This was presumably due to the heterogeneous nature of the DNA analyzed. Single-strand conformational polymorphism analysis of DNA from laser capture microdissected cells of paraffin-embedded AFB1-induced tumor tissue sections stained for p53 produced banding patterns consistent with point mutations in 18 of 30 (60%) DNA samples. Direct sequencing of the microdissected samples revealed mutations at numerous different codons in exons 5, 6, and 7. Of 26 mutations found in microdissected regions from adenomas and carcinomas, 9 were G:C-->A:T transitions, 11 were A:T-->G:C transitions, and 5 were transversions (2 G:C-->T:A, 2 T:A-->A:T, and 1 A:T-->C:G), whereas 1 deletion mutation was identified. The concordance between immunostaining and molecular detection of p53 alterations was 72% when laser capture microdissection was used versus 17% based on whole tumor analysis. The high mutation frequency and heterogeneous staining pattern suggest that p53 mutations occur relatively late in AFB1-induced mouse lung tumorigenesis and emphasize the value of analyzing different staining regions from paraffin-embedded mouse lung tumors.     

P53 expression in esophageal dysplasia - a possible biomarker for carcinogenesis of esophageal squamous-cell carcinoma

The tumor suppressor gene product p53 has been detected in a high percentage of esophageal squamous cell carcinoma. To evaluate the role of this protein in carcinogenesis, we examined the p53 overexpression both in esophageal dysplasia and in esophageal squamous cell carcinoma in the same patients. Using anti-p53 antibodies pAb1801 and CM-1, we analyzed immunohistochemically 36 dysplastic lesions from 36 patients with esophageal cancer. Nuclear p53 was detected in 14 of 36 dysplasias (39%). From mild to moderate to severe dysplasia, p53 positivity showed tendency to increase in number. Seventeen of the 36 squamous cell carcinomas showed p53 expression (47%). There was a significant concurrent p53 expression in esophageal dysplasia and its related squamous cell carcinoma (p=0.00345). These results indicate that p53 mutation is closely associated with the initiation of this cancer.     

Adenosquamous carcinoma of the esophagus. Clinicopathologic study of 18 cases

OBJECTIVES: Adenosquamous carcinoma (ASC) of the esophagus is an uncommon form of esophageal cancer. Despite isolated case reports on this tumor type, no large clinicopathologic series appears to have been studied at a single institution. METHODS: At our institution, 20 cases of ASC were diagnosed pathologically between 1970 and 2001 (20/2,056 total esophageal cancers; 1.0%). Excluding 2 patients who received preoperative radiation therapy, 18 were selected for review of their clinicopathologic features, including survival time, in comparison with those of patients with conventional squamous cell carcinomas (SCCs; n = 850) and adenocarcinomas (ACs; n = 40) of the esophagus. RESULTS: The location and macroscopic type of the ASCs were similar to those of the SCCs. ASC tumors were significantly smaller than SCC (p = 0.004) and AC (p = 0.012) tumors, and the depth of invasion of ASCs was significantly less than that of SCCs (p = 0.028). Lymphatic permeation and blood vessel invasion were seen in 14 (77.8%) and 7 (38.9%) of the 18 patients with ASCs, respectively, and intraepithelial carcinoma contiguous to the main lesion was evident in 10 cases (56.6%). The cumulative postoperative survival rates of patients with ASC at 3, 5 and 10 years were 71.5, 63.6 and 47.7%, respectively, the outcome being significantly better than for patients with either SCC (p = 0.027) or AC (p = 0.013). CONCLUSION: In the esophagus, ASCs have better prognosis than conventional SCCs or ACs, probably due to their smaller size and lower stage.     

p53 expression in squamous dysplasia associated with carcinoma of the oesophagus: evidence for field carcinogenesis

Squamous epithelial dysplasia is often observed multifocally in the cancerous oesophagus and is presumably considered to be a pre-cancerous lesion. A mutation of the p53 tumour suppressor gene is commonly identified in oesophageal cancer and dysplasia. p53 mutations can be anticipated immunohistochemically. In order to confirm the biological and clinical significance of p53 expressions in oesophageal field carcinogenesis, immunostaining for p53 in cancerous and multifocal precancerous lesions from resected human oesophagus was systematically investigated, while paying special attention to the contiguity of these lesions. Lesions expressing p53 were detected in 46.5% (20 of 43 lesions) of the invasive carcinoma, and in 51.0% (46 of 90 lesions) of the carcinoma in situ, and in 51.4% (92 of 179 lesions) of the dysplasia. Next, the p53 expression in dysplasia was compared with that in carcinoma for the same case. 37 of 39 (94.8%) dysplasias contiguous to p53-positive carcinomas also expressed p53 (P<0.0001). On the other hand, the isolated dysplasias without contiguity to p53-positive carcinomas, only expressed p53 protein in 44.0% (11 of 25 lesions). No significant correlations were found between the p53 staining and either the clinicopathological features or prognosis. Discordant p53 alterations, such as those seen in cancerous and isolated precancerous lesions, may thus demonstrate further evidence for a multicentric or field carcinogenesis of the human oesophagus.     

Infrequent p53 mutations in arsenic-related skin lesions

Oral arsenic exposure increases the risk for a variety of benign and malignant skin lesions, but the molecular mechanism of the carcinogenic effect is poorly understood. Arsenic-related squamous cell carcinomas of the skin can develop either de novo or progress from Bowen's disease lesions. Arsenic-related basal cell carcinomas develop usually in non-sun-exposed areas and are multiple. Because p53 tumor suppressor protein is a protective cellular molecule against environmental carcinogens and mutations in the p53 gene are frequent in nonmelanoma skin cancers, we studied p53 in 23 premalignant or malignant skin lesions from seven patients with a history of arsenic medication. The eighth patient studied (with six lesions) had a long standing exposure to UV radiation. Accumulation of the p53 protein was detected (with a monoclonal DO-7 antibody) in 78% of the lesions from cases with arsenic exposure. Two of the six (30%) arsenic-related premalignant lesions and in addition one UV related carcinoma in situ lesion were clearly and repeatedly positive when p53 exons 5 to 8 were screened by a nonradioactive single-strand conformation polymorphism (SSCP) analysis. Only one of the arsenic-related lesions was confirmed by sequencing to have a mutation (a CC to TT double transition). No indications of mutations were found among the 18 basal cell carcinoma or two squamous cell carcinoma lesions studied. Our results suggest that the frequent accumulation of p53 protein in arsenic-related skin lesions is not due to p53 mutations. which may not be a prerequisite in the development of arsenic-induced skin cancers.     

食管鳞状细胞癌中nm23-H1和p53蛋白表达及其相互关系

目的:探讨食管鳞癌组织中p53和nm23-H1蛋白的表达与癌组织分化浸润转移的关系,以及探讨两者之间的相关性,并进一步分析癌组织中p53和nm23-H1蛋白表达对食管癌患者的预后意义。方法:采用免疫组织化学(S-P法)方法对100例人食管鳞癌组织中的p53和nm23-H1蛋白的表达情况进行检测。结果:100例食管鳞癌组织中,nm23-H1阳性表达者70例(阳性率为70%),p53阳性表达者64例(阳性率为64%)。nm23-H1蛋白表达与食管癌淋巴结转移有关(P<0.025),与食管鳞状细胞癌的分化程度、肿瘤部位、浸润深度、病变长度以及患者性别、年龄无关(P>0.05)。p53蛋白表达与食管鳞状细胞癌的分化程度、浸润深度有关(P<0.05),与食管癌淋巴结转移、肿瘤部位、病变长度、患者性别、年龄无关(P>0.05)。高分化鳞癌组织中p53明显低表达(29.2%);低分化鳞状细胞癌组织中p53表达明显增高(71.4%)。食管外膜受累者p53表达较高(56%);仅发生食管粘膜和(或)粘膜下浸润组的癌组织中未发现有p53蛋白的表达。食管癌组织中nm23-H1蛋白低(高)表达与p53高(低)表达之间有明显相关性(P<0.01)。nm23-H1和p53蛋白表达亦与食管癌的TNM分期密切相关(P<0.05)。食管癌TNM分期越晚,其癌组织中nm23-H1蛋白表达越低,p53蛋白表达越高。结论:nm23-H1基因低表达与p53基因高表达可能在食管鳞状细胞癌浸润转移过程中发挥重要作用。nm23-H1可以作为食管鳞状细胞癌患者预后的基因标记,其蛋白表达产物的检测可以用于患者预后的判断,并为患者治疗方案的制定提供参考。     

Histopathologic findings of minute foci of squamous cell carcinoma in the human esophagus

To examine the histogenesis and progression of esophageal squamous cell carcinoma, 76 cases of a primary squamous cell carcinoma were reviewed retrospectively, and 16 lesions of squamous cell carcinoma of the esophagus less than 1.0 cm in diameter were studied histopathologically. None of the patients had received radiation therapy preoperatively. Among 16 foci, 13 were intraepithelial carcinomas, and three were restricted to within the mucosa. In two patients with a solitary, minute cancer, there were no associated areas of dysplasia. In 11 patients with multiple primary minute foci, seven contained 14 areas of dysplasia in the esophagus. There was no continuity between the minute foci of carcinoma and areas of dysplasia. These findings are interpreted to mean that dysplasia is a "subcancerous" lesion rather than a "precancerous" one and that various degrees of lesions such as dysplasia and carcinoma occur multicentrically in the same esophagus. The sequence of dysplasia to carcinoma must be examined using the techniques of molecular biology.     

p53和nm23-H1蛋白表达与食管癌浸润转移的关系

Objective To study the relationship between expression of p53 and nm23-H1 and differentiation, invasiveness and metastasis in human esophageal carcinoma, and the correlation between expression of p53 and nm23-H1. Methods Expression of p53 and nm23-H1 in 50 patients with squamous cell carcinoma of esophagus was detected by using immuno-histochemical S-P methods. Results 35 cases (70%) and 32 cases (64%) of esophageal squamous cell carcinoma were positive for nm23-H1 protein and p53 protein, respectively. The expression of nm23-H1 was related to lymphatic metastasis (P<0.025), but not related to tumor differentiation, invasiveness, tumor location, tumor length, patient's gender and age (P>0.05). The lymphatic metastasis location positive group had a very lower expression of nm23-H1 and the negative rate was 70.8%, but the negative group had a higher expression and the positive rate was 65.4%. The expression of p53 was related to tumor differentiation and invasiveness (P<0.05), but not related to lymphatic metastasis, tumor location, tumor length, patient's gender and age(P>0.05). Among the three groups, the high differentiation group had the lowest expression of p53 and the positive rate was 29.2%, but the low differentiation group had the highest positive rate (71.4%). As for tumor invasiveness, the group of outer membrane of esophagus infiltrated had the highest p53 protein positive rate (56%), but in the group, of mucous or submucous layer infiltrated p53 protien was not detectable. The low expression of nm23-H1 and the high expression of p53 were also correlated. The expression of nm23-H1 and p53 were both correlated with TNM stage of esophageal carcinoma (P<0.05). The better esophageal carcinomas differentiated, the lower nm23-H1 expressed and higher p53 expressed. Conclusion Low expression of nm23-H1 and high expression of p53 play an important role in the progression of squamous cell carcinoma of esophagus. Nm23-H1 might beta gene markef in the prophecy of patients' prognosis and benefit tumor treatment clinically.     

Carcinoma of the esophagus with adenoid cystic differentiation

Adenoid cystic carcinoma of the esophagus is a relatively rare lesion which characteristically exhibits a clinically aggressive behavior. In spite of this aggressive nature, it is most often referred to as a counterpart of the more common adenoid cystic carcinoma of salivary gland origin, a comparatively indolent tumor. In this report, the clinical and pathologic findings in a series of six cases of esophageal adenoid cystic carcinomas are contrasted with those of typical salivary gland lesions, and also compared to similar tumors exhibiting "adenoid cystic" differentiation arising in other extrasalivary gland sites. It is concluded that the esophageal tumors, as well as certain similar lesions arising in other extrasalivary gland sites, represent a class of poorly differentiated basaloid neoplasms distinct both clinically and morphologically from the common adenoid cystic carcinoma of salivary gland origin.     

The prognostic impact of O6-Methylguanine-DNA Methyltransferase (MGMT) promotor hypermethylation in esophageal adenocarcinoma

Promotor hypermethylation is a common event in human cancer. O6-Methylguanine-DNA Methyltransferase (MGMT) is a gene involved in DNA repair, which is methylated in a variety of cancer types. In colorectal cancer and lung cancer, hypermethylation of MGMT has been correlated with p53 mutation. In the present study, 132 samples of esophageal adenocarcinoma and 58 samples of normal esophageal tissue were investigated for MGMT hypermethylation status by methylation-specific real-time PCR and results were correlated to clinicopathological parameters, patient's survival, p53 mutation and expression of p53 protein and MGMT protein. In the carcinomas, hypermethylation of MGMT was found in 63.6% of cases and loss of MGMT protein expression in 48.5% of cases. Furthermore, MGMT hypermethylation was found in 5.7% of normal esophageal smooth muscle tissue, in 20.0% of esophageal squamous epithelium and in 61.5% of nonneoplastic Barrett's mucosa. In the carcinomas, hypermethylation of the MGMT gene was correlated with loss MGMT protein expression (p < 0.0001) and with high tumor differentiation (p = 0.0079). In contrast, no correlation between MGMT hypermethylation, Lauren's classification, WHO classification, tumor size, gender, age, pT category and pN category, and p53 status was found. Neither MGMT hypermethylation nor loss of MGMT protein expression was correlated with patient's survival. In conclusion, MGMT hypermethylation in esophageal adenocarcinoma is a frequent event that is associated with loss of MGMT protein expression but not with patient's outcome.     

Clinicopathologic characteristics of superficial spreading type squamous cell carcinoma of the esophagus

Intraepithelial carcinoma concomitant with the main tumor is a conspicuous feature in squamous cell carcinoma (SCC) of the esophagus. The aim of the current study was to clarify the clinicopathologic features of superficial spreading type SCC of the esophagus. Ninety-seven patients with esophageal squamous cell carcinoma, whose main carcinoma is invading the mucosa or submucosa, were investigated in the current study. The clinicopathologic features were compared between 13 cases demonstrating a superficial spreading type carcinoma in which the spreading size of the tumor was 5 cm or more in length and 84 cases with the size less than 5 cm. Although no significant difference was observed regarding lymphatic invasion, venous invasion, intramural metastasis and lymph node metastasis, the survival rate of patients with superficial spreading type carcinoma was much better than that of patients with ordinary superficial carcinoma of the esophagus. Coexistence of superficial spreading type carcinoma may be correlated with a favorable prognosis of patients with superficial esophageal SCC.     

Phase I/II adenoviral p53 gene therapy for chemoradiation resistant advanced esophageal squamous cell carcinoma

We investigated the feasibility, safety, biological activity and therapeutic efficacy of adenovirus-mediated p53 gene transfer in patients with chemoradiation resistant advanced esophageal carcinoma. Eligible patients were not surgical candidates and had measurable, advanced squamous cell carcinoma of the esophagus that was resistant to chemoradiation therapy. On a 28-day cycle, intratumoral injections of Ad5CMV-p53 (INGN 201; ADVEXIN) were administered on days 1 and 3 at four dose levels (10 x 10(11) particles to 25 x 10(11) particles) and treated for up to five cycles. Ten patients received a total of 26 cycles with no dose-limiting toxicity. Administration of multiple courses was feasible and well-tolerated. Local tumor responses revealed stable disease in nine cases and progressive disease in one case. The overall responses were stable in six and progressive in four cases. Using polymerase chain reaction (PCR) analyses, gene transfer and p53 specific transgene expression were detected in tumor biopsy tissue from all patients. mRNA levels of p53, p21 and MDM2 increased in all but one case. Three patients showed absence of disease upon repeat biopsies. Substantial improvement in swallowing was observed in one patient with stenotic lesions. Intratumoral injection of Ad5CMV-p53 is safe, feasible and biologically active when administered in multiple doses to patients with esophageal cancer. Observations from this study indicate that this treatment results in local antitumor effects in chemoradiation resistant esophageal squamous cell carcinoma.     

p53功能失活在食管鳞癌中的表达及意义

目的：建立一种评价肿瘤生物学特性的新方法--p53功能失活检测法，并探讨p53功能失活与食管鳞癌TNM分期(tumor,nodes,metastasis staging）和组织学分级的关系。方法：采用p53功能测定法对45例新鲜食管鳞癌组织和正常食管组织进行p53功能检测（p53基因突变检测作为对照），将检测结果与患者的TNM分开期和组织学分级进行统计学分析。结果：p53功能失活率为64%，明显高于p53基因突变率49%。p53功能失活和食管鳞癌的TNM分期有关，分期越高，p53功能失活率越高；p53功能失活和食管鳞癌的组织学分级有关，分级越高，p53功能失活率越高。结论：p53功能失活有望成为一种评价食管鳞癌生物学特性的新指标；p53功能失活与食管鳞癌的TNM分期和组织学分级有关。