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S D Finkelstein

Publications and source records attributed to S D Finkelstein.

At least 55 records · Page 3Linked to original sources

Immunohistochemical evaluation of erbB-2 and p53 protein expression in benign and atypical human meningiomas.

Meningiomas arise from the arachnoidal cells surrounding the brain and are one of the most common tumors of the central nervous system. These tumors are known to be hormonally modulated and may occur in association with breast carcinoma. Overexpression of the erbB-2 oncogene product and mutation of the tumor suppressor p53 gene are considered causal driving forces in the pathogenesis of adenocarcinomas of the breast. To determine whether abnormal expression of these genes also plays a role in the pathogenesis of meningiomas, we analyzed the expression of the erbB-2 and p53 proteins in 17 atypical and 35 typical meningioma tissue specimens by immunohistochemistry. The staining intensity was assigned a relative value of 0 to 5+, where 5+ denoted confluent immunoreactivity, 4+ to 1+ denoted varying degrees of focal positivity, and 0 denoted no evidence of staining. Levels of p53 and erbB-2 immunohistochemical staining were then correlated with tumor histology. For p53 immunoreactivity, typical meningiomas had a median staining score of 1.0, compared to 4.0 for atypical meningiomas (P < 0.0001, Mann-Whitney U test). For erbB-2 immunoreactivity, typical meningiomas had a median staining score of 5.0 compared to 1.0 for atypical meningiomas (P < 0.0001, Mann-Whitney U test). The inverse relationship between levels of erbB-2 and p53 immunoreactivity was found to be statistically significant (P < 0.0001, ANOVA). Expression of the erbB-2 protein was not associated with gene amplification or the presence of activating mutation in the transmembrane region of the protein. These findings may improve our understanding of the molecular events that occur in the neoplastic transformation of meningothelial cells. The patterns of erB-2 and p53 immunoreactivity may prove to be useful markers with which to identify potentially more malignant meningiomas.

Base Sequence↗

Prognostic value of TP53 and K-ras-2 mutational analysis in stage III carcinoma of the colon.

BACKGROUND: Genetic mutations involving oncogenes and tumor-suppressor genes occur in carcinogenesis, and may affect biologic behavior of neoplasms. In this study, we analyzed the prognostic value of mutational analysis in colon carcinoma. PATIENTS AND METHODS: Archival pathology specimens from 70 consecutive patients, resected for stage III colon carcinoma, were analyzed for point mutations by amplification and direct sequencing of exons from the K-ras-2 and the TP53 genes (topographic genotyping). Mutations were compared with adverse histopathologic features (poor differentiation, vascular and lymphatic invasion, mucin production) as prognostic markers. RESULTS: Five-year survival was 75% in patients with nonmutated lesions, significantly lower (21%) with TP53 mutations (P = 0.01), and intermediate with K-ras-2 only (45%) or both K-ras-2 and TP53 mutations (36%). A TP53 mutation carried the highest relative risk of death (2.39; 95% confidence interval, 1.29 to 4.42; P = 0.006). There was an additive effect on the risk of death between TP53 mutations and adverse histopathologic features. CONCLUSIONS: The information derived from mutational analysis is creating new prognostic variables that may play a role in the choice of therapy for colorectal carcinoma.

Aged↗

Comparative p53 mutational analysis of multiple primary cancers of the upper aerodigestive tract.

BACKGROUND: Tumors arising in the upper aerodigestive tract (UAT) are often associated with predisposing factors that place the patient at risk for development of multiple synchronous or metachronous tumors. The aim of this study was to evaluate p53 as a susceptibility gene in UAT malignancy. METHODS: Seventeen patients with 41 separate primary tumors involving esophagus (n = 15), larynx (n = 14), pharynx (n = 6), lung (n = 2), mouth (n = 2), and tongue (n = 2) were analyzed for the presence and specific genotype of p53 point mutation. Immunohistochemical staining of p53 and topographic genotyping consisting of polymerase chain reaction amplification and direct sequencing of p53 exons to 5 to 8 were performed. RESULTS: Eleven tumors were metachronous (6 months to 11 years), and 11 were synchronous. We found p53 point mutations in 19 (46.3%) of 41 tumors in exons 8 (n = 11), 7 (n = 4), 5 (n = 3), and 6 (n = 1). Tumors possessed either wild-type p53 or a single type of point mutation. Metastases displayed the identical genotype of its primary tumor in all cases. Most importantly, p53 genotype was found to be completely discordant between separate primary tumors for the same patient. CONCLUSIONS: Complete discordance in p53 genotype between separate primary UAT cancers strongly indicates that p53 is not functioning as a susceptibility gene in this setting.

Adult↗

The role of p53 mutation and protein expression in primary and recurrent adenoid cystic carcinoma.

Adenoid cystic carcinoma (ACC) is a malignant tumor of salivary gland origin having a propensity for spread by direct extension or perineural invasion with frequent recurrences. Previous reports have shown that tumor behavior is not always predicted by histological pattern or stage. Little is known of the role of p53 tumor suppressor gene mutation and altered protein expression with respect to ACC pathobiology and recurrence. The authors analyzed a group of 14 ACC specimens (seven primary; seven recurrent) from 13 patients treated between 1987 to 1993. Formalin-fixed, paraffin-embedded specimens were reviewed and subjected to, immunohistochemistry (p53, DO-7, DAKO, Nutley, NJ; and WAF-I, Ab-1, Oncogene Sciences, Uniondale, NY) on 4-microm-thick histological sections as a prelude to p53 genotyping. In one case, sequential material representing primary and recurrent tumor was analyzed. Each tumor specimen was topographically genotyped for p53 point mutational change. Minute tissue samples were removed from unstained sections, polymerase chain reaction (PCR) amplified for p53 exons 5 to 8, and then underwent direct DNA sequencing. Six of seven primary ACCs were p53 immunostain negative. Four of seven recurrent (57%) ACCs were p53 immunopositive. These tumors showed varying degrees of p53 immunopositivity ranging from diffuse, intense staining of most tumor cells (n = 1) to interspersed, strongly positive cells mixed with predominantly p53 immunonegative cells (n = 4). All tumors were WAF-I immunostain negative. Two of the most immunopositive recurrent tumors each manifested a single type of p53 point mutation detected by p53 DNA genotyping (p53 exon 5:codon 175 and p53 exon 6:codon 199). In the case in which both primary and recurrent tumor was available, only the recurrent tumor contained point mutational damage. Negative immunostaining for p53 in primary ACC suggests that p53 mutation is not important in early events involving development of this tumor. In contrast, the frequent presence of p53-positive cells and the detection of point mutations in recurrent ACC suggests that p53 alterations are involved in later stages of tumor progression, important in the phenomenon of ACC recurrence.

Adult↗

Primary mediastinal and testicular seminomas: a comparison of K-ras-2 gene sequence and p53 immunoperoxidase analysis of 26 cases.

Primary mediastinal seminomas (MS) are rare tumors. Histologically, they are similar to their counterpart in the gonads. The survival rate has varied from 50% to 85% in different series. However, large series of these tumors primarily in the mediastinum are lacking. At the molecular level, a few reports document K-ras mutations in up to 40% of testicular seminomas (TS), localized predominantly to codon 12. Reports on TS p53 immunohistochemistry (IHC) range from negative to overexpression approaching 90% of cases, and by sequence analysis one small series showed a 23% mutation rate. To date, no analyses have been performed for either K-ras mutations or p53 immunohistochemical expression in primary MS. The authors studied 13 cases each of primary MS and TS from archival formalin-fixed, paraffin-embedded sections in which adequate tumor sampling and clinical history, including serological studies, and histological, histochemical, and IHC staining, were performed to confirm the diagnosis. p53 immunoperoxidase staining using citrate buffer/microwave antigen retrieval was performed. Topographic genotyping was performed on 5-microns-thick tissue sections up to 17 years old, in which the neoplastic cell population was sampled. Additionally, multiple sites within a given cases were sampled to determine clonality of the tumor cell population. Polymerase chain reaction and subsequent sequence analysis of the K-ras-2 exon-1 gene was used for mutation analysis. Focal weak staining with p53 IHC was observed in 4 of 13 (31%) MS and 10 of 13 (77%) TS cases, with all remaining cases being negative (P < .05). Only one MS case (8%) showed K-ras mutation (codon 13 GGC > GAC; glycine > aspartate), which is in contrast to 2 of the TS cases (15%), showing codon 12 mutations. All the remaining cases were wild type. Therefore, primary mediastinal seminomas appear to be different in their K-ras sequence and p53 immunostain profile from TS. Codon mutation type may be useful in determining primary versus metastatic origin of a mediastinal seminoma.

Adolescent↗

Lymphoepithelial carcinoma of the larynx and hypopharynx: study of eight cases with relationship to Epstein-Barr virus and p53 gene alterations, and review of the literature.

Eight cases of lymphoepithelial carcinoma (LEC) of the larynx and hypopharynx were evaluated for clinicopathologic features, and the presence of the Epstein-Barr virus (EBV) and p53 alterations. The seven men and one woman, all of non-Asian descent, averaged 64 years of age. Eighty-eight percent had histologically confirmed cervical lymph node metastasis at diagnosis. None had systemic disease. Seven of eight patients available for follow-up (mean, 17.7 months) were alive and free of disease, although one did develop recurrent tumor in the neck. Four tumors were composed, histologically, of pure LEC. Four others had foci of both LEC and conventional squamous cell carcinoma. All eight tumors exhibited alterations in p53 expression, but none was positive for EBV. Combining these 8 cases with the 15 previously published cases in the English literature indicate that LEC in this site is a rare, rather aggressive tumor, primarily of older adults (mean, 62 years) with a propensity for early cervical lymph node metastasis and eventual distant dissemination and death from disease in about one third of patients. Although p53 alterations are common and of no apparent prognostic significance, LEC at this site seems to have little, if any, relationship to the EBV in patients of non-Asian origin.

Aged↗

Increased expression of keratinocyte growth factor messenger RNA associated with inflammatory bowel disease.

BACKGROUND & AIMS: Alterations in intestinal epithelial cell function are common in inflammatory bowel disease (IBD). Keratinocyte growth factor (KGF) is an epithelial cell-specific mitogen. The aim of this study was to examine IBD tissue for altered KGF expression. METHODS: Expression levels of the KGF and KGF receptor transcripts were analyzed by ribonuclease protection assay. The cellular localization of each transcript was determined using in situ hybridization. RESULTS: KGF messenger RNA levels were increased in inflamed IBD tissue in comparison with control tissues. In normal tissue, KGF messenger RNA was localized to the mesenchymal cells at the tip of the villi in the small intestine and directly underlying the mature enterocytes in the colon, whereas in IBD it was present throughout the lamina propria, although distinct from the germinal centers. The topographic distribution of the KGF in situ hybridization signal in IBD was similar to that observed for T lymphocytes. In contrast, KGF receptor transcripts were localized to the cryptal region of the mucosal epithelium in both normal and IBD tissue, with no apparent differences in the level of expression. CONCLUSIONS: The increased expression of KGF in IBD suggests that it may be involved in mediating the altered regulatory functions of intestinal epithelial cells in this disease.

Colon↗

Pleomorphic (giant and spindle cell) carcinoma is genetically distinct from adenocarcinoma and squamous cell carcinoma by K-ras-2 and p53 analysis.

Pleomorphic carcinoma (PC) of lung is a poorly differentiated epithelial neoplasm predominantly composed of pleomorphic giant and/or spindle tumor cells. The WHO classification of lung cancer recognizes spindle cell carcinoma and giant cell carcinoma as separate neoplasms related to squamous cell carcinoma (SqC) and large cell carcinomas, respectively. Further, the presence of foci of SqC or adenocarcinoma (AdC) in, respectively, 10% and 45% of PC produces additional uncertainty as to the distinctive nature of this tumor type. In this study, the authors tested the hypothesis that PC is an entity separate from SqC or AdC by evaluating the mutational spectrum seen in these tumor types. This is performed by documenting and comparing mutation type and rate of K-ras-2 and p53 genes in PC, SqC, and AdC. Comparative DNA sequence and immunohistochemical analysis were performed on 22 PC, 42 SqC, and 97 AdC. Archival formalin-fixed, paraffin-embedded tissues formed the basis of the study. Immunohistochemical staining with p53 antibody (DO-7) revealed statistically significant differences in the intensity and frequency of staining of PC (weak, 86% of cases) versus SqC (strong, 52% of cases) and AdC (strong, 27% of cases) (P < .001). Topographic genotyping with subsequent polymerase chain reaction (PCR) and sequence analysis of K-ras-2 showed mutations in significantly fewer cases of PC (9%, 2 of 22 cases) than in AdC (36%, 35 of 97 cases) or SqC (0%, 0 of 42 cases) (P < .001). Pleomorphic carcinoma also showed significantly fewer p53 point mutations (14%, 3 of 22 cases) than did AdC (27%, 26 of 97 cases) of SqC (43%, 18 of 42 cases) (P < .01). Finally, the p53 mutations in PC were more common in exon 7, whereas those in SqC and AdC were more frequent in exon 8. These findings reveal significant differences in the pattern and frequency of genetic mutations between PC and pulmonary SqC and AdC and are in keeping with the separate histopathologic classification of these tumors.

Adenocarcinoma↗

Relationship of p53 gene alterations with tumor progression and recurrence in olfactory neuroblastoma.

Olfactory neuroblastoma (ONB) is a rare neuroectodermal tumor whose clinical course is not effectively predicted by initial stage or grade; p53 tumor suppressor gene alterations have not been determined concerning the ONB pathobiology and recurrence. We analyzed 18 formalin-fixed, paraffin-embedded ONB specimens (12 primary tumors and six recurrences or metastases) from 14 patients for p53 alterations using immunohistochemistry for p53 and WAF1 together with topographic genotyping (selection of minute tissue targets from unstained sections, PCR [polymerase chain reaction] amplification of exons 5-8 followed by direct DNA sequencing). Sequential material representing tumor recurrence or metastasis was available in four cases to compare genetic alterations over time in the same patient. None of the cases showed strong, diffuse p53 immunostaining. Focal weak to moderate intensity staining was evident in nine of 14 cases. Mutations in p53 were not detected in any of the cases, suggesting hyperexpression of p53 wild-type protein. Hyperexpression was further confirmed by correlation of WAF-1 and p53 immunopositivity. Importantly, in four cases with recurrence or metastasis, tumors manifested p53 wild-type hyperexpression. It appears that p53 point mutation does not play an important role in the initial development of ONB; however, p53 wild-type hyperexpression may occur in subsets of ONB likely to show local aggressive behavior and a tendency for recurrence. Wild-type p53 hyperexpression may be an important event in later stages of ONB growth and progression.

Adult↗

Analysis of p53, K-ras-2, and C-raf-1 in pulmonary neuroendocrine tumors. Correlation with histological subtype and clinical outcome.

Neuroendocrine tumors of lung, including typical carcinoid (TC), atypical carcinoid (AC), large cell neuroendocrine carcinoma (LCNEC), and small cell lung carcinoma (SCLC) constitute a spectrum of malignancies in which the pathologist at times has difficulty in discerning tumor subtype and aggressiveness in a reproducible fashion. Therefore, 59 primary neuroendocrine lung tumors including 10 TCs, 26 ACs, 15 LCNECs, and 8 SCLCs were selected from cases collected from 1976 to 1988 and immunostained for p53 protein. All of these tumors were also genotyped for specific point mutational damage affecting p53 (exons 5, 7, and 8; with ACs additionally sequenced for p53 exon 6); 13 tumors for K-ras-2 (exon 1); and 31 tumors for c-raf-1 (exon 15) growth-regulatory genes. Genotyping was performed on topographically selected, minute tumor samples removed from unstained formalin-fixed, paraffin-embedded tissue sections (topographic genotyping) using polymerase chain reaction and direct sequencing. The distribution of p53 immunohistochemical staining had four patterns: negative in TCs, one-half of ACs, 3 of 15 LCNECs, and 1 of 8 SCLCs; less than 10% but more than five tumor cells per 10 high power fields (focal) in a subset (7 of 26) of aggressive ACs; 10 to 49% of tumor cells (patchy) in a subset (6 of 26) of ACs with a higher grade of aggressiveness; and 50 to 100% of tumor cells (diffuse), exclusively seen in LCNECs (12 of 15) and SCLCs (7 of 8). Three patterns of immunohistochemical staining intensity of p53 protein were seen: negative, weak or mild, and moderate to marked. SCLCs and LCNECs accounted for cases of moderate to marked staining and were the only ones to have mutations in p53 exons 5, 7, or 8. No mutations were found in AC and TC, showing absent to weak staining and no staining, respectively. The difference in distribution and staining intensities between LCNEC and SCLC compared with AC and TC was statistically significant (P < 0.001). Patients having AC with patchy p53 immunostaining usually had survival limited to 3 years, whereas those having AC with focal p53 immunostaining subsequently developed metastatic or recurrence of AC disease (P < 0.05). The absence of point mutations in cases with patchy or focal immunostaining suggests increased expression of wild-type p53 tumor suppressor protein likely in response to growth deregulation in a more aggressive subtype of AC. A novel hypothesis is presented in regard to these findings. K-ras-2 and c-raf-1 gene sequence analysis showed no evidence of point mutational change in any of the tumors studied. The TC and AC categories are therefore genetically distinct from the higher grade neuroendocrine SCLC and LCNEC. Immunohistochemistry for p53 on AC lung tumors may be helpful to delineate cases at higher risk for aggressive behavior. Additionally, although LCNEC is categorized as a non-small-cell carcinoma, it is more akin genetically and immunohistochemically to SCLC.

Carcinoid Tumor↗

Peritoneal silicosis.

A 73-year-old man with a clinical diagnosis of pulmonary silicosis (long-standing exposure to silica, pulmonary infiltrates, and flu-like symptoms) presented to the emergency room with fever, acute biliary colic, and cholelithiasis. The patient had a 2-year status postchemotherapy with complete remission of hepatic and splenic malignant lymphoma. At laparotomy we found studding of the undersurface of the diaphragm with multiple small dark nodules. Owing to the patient's history of previously treated abdominal malignant lymphoma, the lesions were grossly interpreted as abdominal lymphomatosis. The microscopic appearance of the lesions suggested silicotic nodules, which were confirmed by digital scanning electron microscopy and roentgenographic microanalysis performed on formalin-fixed, paraffin-embedded tissue. This is an unusual extrapulmonary pattern of peritoneal seeding in silicosis.

Aged↗

Multicentric primary adenocarcinomas of the midgut: the first case report.

Multicentric adenocarcinomas of the midgut have not been described; even multiple adenocarcinomas limited to the small intestine are extremely uncommon, with only 14 cases reported in the literature. We report a case of multicentric synchronous involvement of the entire midgut with adenocarcinoma in a 52-yr-old Polish woman who had more than 30 lesions extending from duodenum to mid-transverse colon. There was no family history of cancer. Preoperative evaluation and intraoperative exploration were negative for primary malignancy of the lungs, breasts, ovaries, pancreas, and other parts of the gastrointestinal tract. Results of histopathological examination, immunohistochemical staining, and ras mutational analysis of the lesions uniformly support the diagnosis of multicentric poorly differentiated adenocarcinoma. The cause for this unusual presentation is unknown, although sporadic genetic alteration(s) of oncogene(s) might have been the precipitating event.

Adenocarcinoma↗

K-ras-2 and p53 genotyping of intestinal-type adenocarcinoma of the nasal cavity and paranasal sinuses.

Intestinal-type adenocarcinoma (ITAC) of the nasal cavity and paranasal sinuses is an uncommon neoplasm manifesting a variety of histologic growth patterns, most of which are reminiscent of colorectal adenocarcinoma. To determine whether this morphologic resemblance is mirrored in equivalent genetic alterations, a series of ITAC was genotyped using archival, formalin-fixed tissues for point mutational damage in K-ras-2 oncogene and p53 tumor suppressor gene, forms of DNA damage frequently found in colorectal adenocarcinoma. In contrast to colorectal adenocarcinoma, which demonstrates K-ras-2 mutation in about 50% of cases, ITAC showed no evidence of K-ras-2 mutation. p53 mutations were present in 18% of ITAC (2 of 11) compared to more than 75% incidence of p53 mutation seen in colorectal adenocarcinoma. Fifty-eight percent of ITAC demonstrated scattered positive p53 immunohistochemical nuclear staining, but no mutations were identified in exon-5 through exon-8 by genotyping. There was no specific p53 alterations with respect to histologic subtype of ITAC. Although ITAC and colorectal adenocarcinoma are histologically similar, there are important differences at the genetic level based on expression of K-ras-2 and p53 abnormalities.

Adenocarcinoma↗

alpha-Interferon retreatment of patients with chronic hepatitis C.

To evaluate the effect of a second cycle of alpha-IFN treatment on patients who have not responded to a first cycle or responded and relapsed, 37 patients, 25 men and 12 women, mean age 41 yr, were retreated with alpha-interferon (IFN). Seven patients responded to the first cycle of treatment, and 30 did not. Five patients who had not responded to the second cycle received a third one. All patients received twice the dose of the first cycle unless they experienced side effects during the first cycle. Thus, nine patients received 9 mU/w, nine received 15 mU/w, and 19 received 30 mU/w for 6 months. Complete response was defined as nondetectable hepatic hepatitis C virus (HCV)-RNA at the end of therapy; sustained response was defined as normal ALT levels with negative serum HCV-RNA at > 6 months after cessation of therapy. Of the 30 nonresponders to the first cycle, eight responded to the second, but only four (13%) had a sustained response. Six of the seven responders to the first cycle responded to the second cycle, but only three had a sustained response (3/7, 43%) (p = NS). Although 33 and 21% (p = NS) of those who were treated with 15 mU/w and 30 mU/w, respectively, showed a sustained response, none of those treated with 9 mU/w had a sustained response (p = NS). Although age or sex of the patients studied had no effect on the response rate, liver histology was an important factor because only noncirrhotics showed a long term response (47 vs 0%; p < 0.02). There was no difference in response rate between patients with chronic active hepatitis and chronic persistent hepatitis. In conclusion, noncirrhotic patients who have not responded or responded and relapsed to a 6-month course of alpha-INF (3-5 mU three times per week) should try a second course at a dose of 15 mU/w. Retreatment may induce complete and long lasting response in 13% of the initial nonresponders and 43% of the initial responders. A second course of alpha-IFN in nonresponding cirrhotics appears ineffective in clearing the virus at the doses used.

Adult↗

Pattern of mutant p53 expression in human astrocytomas suggests the existence of alternate pathways of tumorigenesis.

BACKGROUND: Clinical observations suggest that malignant astrocytomas may arise from well-differentiated, low-grade tumors that have undergone anaplastic progression or may develop de novo. Mutations that alter the function of the p53 gene product are thought to play a critical role in astrocytoma tumorigenesis. The authors studied the pattern of mutant p53 expression in astrocytomas to define its role in the formation of malignant tumors by these different pathways. METHODS: Tissues from 44 astrocytomas corresponding to Grades I-IV of the World Health Organization (WHO) classification were analyzed for the presence of mutations in exons 5, 7, and 8 of the p53 gene using single strand conformation polymorphism (SSCP) and sequence analysis of DNA amplified by the polymerase chain reaction. Immunostaining for mutant p53 proteins was performed on tissues fixed in formaldehyde solution and embedded in paraffin; the tissues were from these 44 astrocytomas and another 103 astrocytomas obtained from archival material. RESULTS: Tumors with mutant p53 genes were reliably identified by immunostaining for mutant p53 proteins. A higher percentage of astrocytomas of histologic Grades II-IV stained positively for p53 than were identified by mutational analysis. The average ages of patients with Grade III/IV astrocytomas with prominent (> 10%) p53 staining and those with sparse (< 10%) or no p53 staining were 44.5, 64.3, and 67.9 years, respectively (P < 0.0001). CONCLUSIONS: The pattern of mutant p53 expression is consistent with a role in driving the progression of low-grade astrocytomas to more malignant tumors. These results provide a genetic basis for the clinical observation that malignant astrocytomas resulting from anaplastic progression occur in a younger patient population than do malignant astrocytomas arising de novo.

Adult↗

K-ras-2 topographic genotyping of pancreatic adenocarcinoma.

OBJECTIVE: To determine the frequency distribution of K-ras-2 point mutation genotypes in pancreatic adenocarcinoma and to evaluate the effectiveness of K-ras-2 genotyping as a means to predict localized disease and potential long-term survival. DESIGN: Topographic genotyping from archival formalin-fixed, paraffin-embedded large- and biopsy-sized tissue specimens as well as cytologic fluid using polymerase chain reaction products and direct sequencing together with clinicopathologic and statistical analysis. SETTING: Tertiary care medical center with molecular diagnostics pathology laboratory. PATIENTS: Patients treated between 1988 and 1993 at Rhode Island Hospital, Providence, yielding 55 primary and 56 metastatic specimens of pancreatic adenocarcinoma. RESULTS: Each primary pancreatic adenocarcinoma was found to contain one of eight specific genotypes that was maintained in all metastatic deposits of that individual tumor. Primary adenocarcinomas confined to the pancreatic bed at diagnosis were predominantly of a normal genotype (56% [14/25]). Pancreatic adenocarcinomas progressing to distant hematogenous metastasis were almost exclusively mutated (88% [7/8]; P < .005). Patients undergoing pancreatic resection (Whipple's operation) and having a normal K-ras-2-genotype (58% [11/19]) had a significantly longer survival (21.3 months) than similar patients with mutated tumors (8.2 months). CONCLUSIONS: The findings support the feasibility of K-ras-2 topographic genotyping to identify potentially indolent disease and suggest a potentially useful role in the preoperative evaluation of pancreatic adenocarcinoma.

Adenocarcinoma↗