Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0677930 (primary tumor)
 20,210 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The progression of carcinoma in situ of the bladder to invasive bladder carcinoma has been shown to be essentially regulated by p53 overexpression. In another study, however, loss of heterozygosity of chromosome 9 has also been shown to be essential for progression to muscle invasive disease. Routine random biopsies for predicting prognosis and deciding on adjuvant intravesical therapy should be abandoned because of the results of a well-designed trial on 1745 patients. The aforementioned study showed that the recurrence and progression rates could be only slightly improved at a cost of more intravesical therapy if random biopsies were done routinely. The survival of patients undergoing radical cystectomy was shown to be strongly affected by the primary tumor stage even in those patients with positive nodes. Radical cystectomy and lymph node dissection alone could be beneficial in node-positive patients if the tumor was confined to the bladder. Neoadjuvant chemotherapy and bladder sparing could be recommended only on selected patients with significant reduction in tumor size after chemotherapy. The response to adjuvant chemotherapy could be prolonged if consolidation surgical intervention is performed on responders. With the help of new prognostic parameters obtained from molecular genetic analysis, the already increasing survival trends in bladder carcinomas will hopefully continue to improve in the near future.
 ...
PMID:Recent studies in bladder cancer. 765 32

Patients who initially develop an upper aerodigestive tract cancer have an increased risk of second primary cancers. We examined TP53 and RAS mutations and p53 protein in 21 tumors from 10 patients with upper aerodigestive tract cancer who developed a metachronous tumor, to assess the genetic changes that occur in multiple primary tumors from the same individual. Thirteen of 21 (62%) tumors were found to have mis-sense mutations of either TP53 or RAS. Six tumors had TP53 mutations in codons 5 to 8 and 10 tumors from 7 patients had mutations of codons 12 or 13 of K-RAS. Only one patient had concordance of a mutation in 2 tumors; this mutation occurred in K-RAS and was accompanied by discordance of TP53 mutation. Three patients had tumors discordant for both TP53 and RAS mutations. Smoking-related tumors had TP53 and RAS mutations which were transversions in 11 (9 G:C to T:A and 2 G:C to C:G) and transitions in 3 (2 G:C to A:T and 1 A:T to G:C). Tumors not associated with smoking contained only transitions (both G:C to A:T). p53 protein was detected by immunohistochemistry in 7 of 13 (54%) tumors and was concordant in the multiple tumors of 3 patients. Three of the 7 tumors staining for p53 also had TP53 mutations. Thus, genetic alterations are discordant in multiple primary cancers and the pattern of mutations is similar to that found in patients with a single primary tumor, supporting the concept that these cancers arise independently.
 ...
PMID:TP53 and RAS mutations in metachronous tumors from patients with cancer of the upper aerodigestive tract. 765 84

Elective cervical lymphadenectomy often is performed for laryngeal carcinoma to eliminate metastatic disease that escapes clinical and radiographic detection. We investigated characteristics of the primary tumor that might predict cervical lymph node status. We obtained archival tissue from 88 laryngectomies--65 with concurrent cervical lymphadenectomies. Of the 40 clinically negative necks that were dissected, 17% showed lymph node metastasis by pathologic examination. The primary tumors were examined immunohistochemically for expression of epidermal growth factor receptor (EGFR), p53, cathepsin D, proliferating cell nuclear antigen (PCNA), and Ki-67-specific antigen, and by flow cytometry for DNA ploidy-cell cycle analysis. Seventy-seven percent of the cases showed aberrant p53 staining, 99% expressed EGFR, 40% produced cathepsin D, 29% were aneuploid, and 54% had a moderate or high synthesis phase fraction (SPF). High grade, aneuploidy, and tumor vascular invasion independently predicted cervical node metastasis (p < .04 each). Supraglottic locale (p < .16) and a raggedly infiltrating invading margin (p < .13) were weakly associated with node positivity. Advanced clinical T status, the expression of EGFR, p53, and cathepsin D, the PCNA and Ki-67 indices, and SPF did not correlate with node metastasis. The presence of cervical node metastasis predicted poor disease-free (p < .005) and overall survival (p < .04). Advanced clinical T status correlated with brief overall survival (p < .02). Tumor site, histopathologic parameters, ploidy, SPF, PCNA and Ki-67 indices, and the expression of p53, EGFR, and cathepsin D did not affect survival. The presence of vascular invasion, high grade, and aneuploidy may help identify which patients would benefit from elective cervical lymphadenectomy. The correlation of cervical lymph node status and clinical T category with survival confirms the results of previous studies.
 ...
PMID:Cervical lymph node status and survival in laryngeal carcinoma: prognostic factors. 766 16

Identification of the genetic alterations that occur in tumors is an important approach to understanding tumorigenesis. We have used comparative genomic hybridization (CGH), a novel molecular cytogenetic method, to identify the gross DNA copy number changes that commonly occur in small cell lung cancer (SCLC). We analyzed ten SCLC tumors (seven primary tumors and three metastases) from eight patients. We found frequent increases in DNA copy number on chromosome arms 5p, 8q, 3q, and Xq and frequent decreases in copy number on chromosome arms 3p, 17p, 5q, 8p, 13q, and 4p. The increase in copy number at 8q24 (MYC) and decreases at 17p13 (TP53), 13q14 (RB), and 3p have previously been identified in SCLC with other methods. Many of the other regions in which we detected common copy number changes have not been reported to be regions of common alteration in SCLC tumors. Comparison of copy number changes between a primary tumor and a metastasis from the same patient showed that they were more closely related to each other than to any of the other tumors. The results of direct CGH analysis of SCLC tumors reported here confirm the existence of copy number changes that we identified previously by using cell lines.
 ...
PMID:Identification of novel regions of altered DNA copy number in small cell lung tumors. 766 37

The issue of whether multifocal breast cancer represents intramammary spread from a single primary tumor or multiple synchronous tumors remains unresolved. We have used a series of immunocytochemical markers, B72.3, DF3, c-erbB-2, SP-1, CEA, and p53, to attempt to answer this question. Of 24 cases with separate discrete synchronous tumors in the same breast, 10 were histologically and immunocytochemically identical, five were histologically similar but immunocytochemically different, two were histologically different but immunocytochemically identical, and in seven cases the tumors were different both histologically and immunocytochemically. In seven of the 24 cases lymph nodes containing metastatic tumor were also available; in each instance, the immunoreactivity of the metastasis was similar to one or other of the tumors in the breast. This study indicates that multifocal breast cancer may result from either intramammary spread from a single primary tumor or multiple synchronous primary tumors.
 ...
PMID:Mechanisms of multifocal breast cancer: an immunocytochemical study. 767 96

We have analysed 78 head and neck carcinomas (50 node metastases and 28 primary tumors including 13 matched specimens) in 65 patients for p53 alterations. Mutations were found in 54 (69%) tumors. Of the 53 mutations within exons, 40 (76%) were missense, five (9%) nonsense and eight (15%) microdeletions or microinsertions. Twenty-five (47%) mutations were transitions mostly G-->A (40%) and 20 (38%) were transversions, mostly G-->T (25%), thus confirming the role of tobacco carcinogens in the induction of these mutations. The incidence of mutations was not different in primary tumors (68%) and node metastases (70%) indicating that this gene alteration was not related to the metastatic dissemination. For eight patients, mutations were observed in matched primary tumors and metastases, indicating clonal dissemination of tumor cells in most of these carcinomas. There was a good correlation between mutations and protein overexpression (Fisher's exact test P < 10(-4). Immunostaining was also observed in basal cells from normal epithelium and in early lesions adjacent to the primary tumor in 11/15 (73%) specimens irrespective of the presence of mutation in the corresponding tumors. These data confirm that p53 overexpression is an early event in the multistep process of epithelial cell carcinogenesis. Loss of heterozygosity for the TP53 locus was detected in 54% of tumors but no association was found with mutation (Fisher's exact test P = 0.14). No mdm-2 amplification was detected in any tumors. No correlation was found between mutation and clinical parameters, the 5-year survival rates were not different (log rank test P = 0.39) in patients with and without mutation. In conclusion, we have shown that p53 gene mutations and deletions and protein overexpression are frequent in the most aggressive head and neck carcinomas but are not associated with disease progression. The presence of protein in normal mucosa and in non-invasive lesions may constitute a biomarker for early stages of carcinogenesis.
 ...
PMID:High incidence of p53 alterations (mutation, deletion, overexpression) in head and neck primary tumors and metastases; absence of correlation with clinical outcome. Frequent protein overexpression in normal epithelium and in early non-invasive lesions. 770 Jun 47

Aberrations of the p53 gene in 26 surgical specimens of human epithelial ovarian carcinomas were examined by single-strand conformation polymorphism (SSCP) analysis of polymerase chain reaction (PCR) products. Seven (27%) of the tumors demonstrated a SSCP band shift in exons 4 to 9 of the gene, including 5 in the region encompassing exons 5 and 6, 1 in exon 7, and 1 in the region encompassing exons 8 and 9. Mutations were clustered in exon 5 in highly conserved regions of the p53 gene. All of the abnormal DNA fragments have been further characterized by direct DNA sequencing. These include five missense mutations (five transitions), a one-base-pair deletion introducing, by frameshift, a stop codon further downstream, and a two-base-pair insertion introducing a stop codon downstream by frameshift. Most mutations were base substitutions, and were clustered in exon 5 (71%), especially codons 175 and 179. The aberrations of the p53 gene were only found in tumors of FIGO stages III and IV. Histologic grading was also reviewed with respect to p53 aberrations. The aberrations were absent in well-differentiated carcinomas. The more undifferentiated the primary tumor, the more frequent p53 mutation (P < 0.05). Our results indicated that the aberrations of the p53 gene were common in epithelial ovarian cancers and p53 aberration may occur late during ovarian cancer evolution.
 ...
PMID:Aberrations of the p53 tumor suppressor gene in human epithelial ovarian carcinoma. 772 34

Mutations in the p53 tumor suppressor gene play an important role in the development of many common human malignancies. In nasopharyngeal carcinomas (NPC), p53 gene mutations were not detected in primary tumors, with one exception for a primary tumor displaying a p53 mutation at codon 280, whereas p53 mutations were identified in some metastatic and nude mouse-passaged NPC specimens. In the present report, 41 NPC primary tumors of the undifferentiated carcinoma nasopharyngeal type (UCNT; 21 from Hong Kong and 20 from Guangxi, southeastern China) were studied. Four point mutations that result in amino acid substitutions were identified by PCR amplification of exons 2-9 and direct DNA sequencing, combined with PCR-single-strand conformation polymorphism analysis. The 4 mutations detected were clustered within the DNA stretch from codon 175 to 177. Our data, taken together with those of others, suggest that mutation in p53 may occur in NPC at various points during tumorigenesis. Alternative mechanisms of p53 inactivation in NPC are also possible.
 ...
PMID:Mutations clustered in exon 5 of the p53 gene in primary nasopharyngeal carcinomas from southeastern Asia. 772 41

We have used culture conditions which simulate the microenvironment of breast tumors for the isolation and propagation of primary breast tumor cells in vitro. In this monolayer setup, the mixture of cells dissociated from primary breast tumors is subjected to self-created gradients of oxygen and nutrients as well as metabolic waste and extracellular pH. The tumor populations isolated under these novel conditions have displayed phenotypic properties characteristic of breast carcinomas, including homogeneous expression of cytokeratin 19, and increased mitochondrial retention of the cationic dye rhodamine 123. Nonmalignant cultures from reduction mammoplasty were unable to survive these conditions. One tumor population which reached passage 10 was aneuploid for chromosomes 15 and 17, and displayed a p53 mutation in exon 8. These studies strongly suggest that the culture conditions described here can suppress the growth of normal breast cells, thereby allowing selective isolation of some populations of slow-growing primary tumor cells in vitro.
 ...
PMID:Selective cell culture of primary breast carcinoma. 778 Sep 60

Our previous study revealed that mutations of the p53 gene were detected by cDNA sequencing in one of four (25%) primary gastric tumors and in five of six (83%) gastric cancer cell lines. It was of interest that all five cell lines established from metastatic lesions had p53 gene mutations, while the single cell line established from a primary tumor lacked an abnormality. Thus, the current study was initiated to determine the frequency of p53 mutations in 10 pairs of samples from primary gastric carcinomas and their lymph node metastases, in addition to morphologically normal gastric mucosa. In addition, we correlated the findings with other relevant molecular markers including the metastasis associated nm23-H1 gene and loss of heterozygosity (LOH) using multiple polymorphic markers for chromosome 17p and sequencing the entire open reading frame (ORF) of the p53 gene. Five of ten (50%) patients were constitutionally heterozygous for one or more 17p and/or p53 probes (pYNZ 22, BamHI RFLP; pMct35.1, Mspl RFLP; php53cl, Bg/II RFLP), while none had LOH at the 17p and/or p53. A Bg/II RFLP for analysis of possible nm23-H1 somatic allelic deletion revealed no LOH out of four informative cases. One paired sample demonstrated the substitution of valine for isoleucine at codon 41 (GTT to ATT) in both primary gastric tumor and metastasis. Another metastatic sample demonstrated the substitution of proline for threonine at codon 278 (CCT to C/ACT) in addition to a non-mutated codon, while only the wild-type p53 sequence was present in the paired primary gastric tumor tissue.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:Comparison of p53 gene mutations in paired primary and metastatic gastric tumor tissues. 790 5


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>