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Biomedical subjects

Y Fong

Publications and source records attributed to Y Fong.

At least 73 records · Page 4Linked to original sources
PubMed2000

Recognition of intrabiliary hepatic metastases from colorectal adenocarcinoma.

Intrinsic involvement of bile ducts, by metastatic colorectal adenocarcinoma growing from within or invading the lumen of bile ducts, is not a well recognized pattern of tumor growth. Clinical, radiographic, operative, and histopathologic aspects of 15 patients with intrabiliary colorectal metastases were described. Fourteen patients were explored for possible hepatic resection. Two had jaundice, two radiographic evidence of an intrabiliary filling defect, 10 intraoperative evidence of intrabiliary tumor, and six microscopic evidence of intrabiliary tumor. Eleven patients underwent hepatic resection. Five of the resected patients developed hepatic recurrence. Four patients were explored for possible repeat resection. One had jaundice, one radiographic evidence of an intrabiliary filling defect, all had intraoperative evidence of intrabiliary tumor, and three microscopic evidence of intrabiliary tumor. Three patients underwent repeat hepatic resection. All patients with preoperative jaundice and radiographic evidence of an intrabiliary filling defect were unresectable. Overall, actuarial five-year survival is 33% for those patients resected versus 0% for those not resected. Intraoperative recognition of intrabiliary tumor at exploration for hepatic resection was more common than clinical, radiographic, or histopathologic recognition. More diligent examination of resected liver tissue by the surgeon and pathologist may increase identification of bile duct involvement and aid in achieving adequate tumor clearance.

Adenocarcinoma↗
PubMed2000

Percutaneous epididymal sperm aspiration in a man with congenital bilateral absence of the vas deferens undergoing an assisted reproduction program.

Surgical retrieval of spermatozoa for in-vitro fertilisation (IVF) programs for severely oligospermic men has been in use for several years now. In the recent 2 to 3 years, clinicians have begun to move towards non-surgical methods of retrieving sperm in certain selected groups of men. Percutaneous epididymal sperm aspiration (PESA) has had good results in terms of number of sperm obtained, as well as the fertilisation and pregnancy rates. The first reported use of such a technique in Singapore is described.

Adult↗
PubMed1999

Hepatic arterial infusion of chemotherapy after resection of hepatic metastases from colorectal cancer.

BACKGROUND: Two years after undergoing resection of liver metastases from colorectal cancer, about 65 percent of patients are alive and 25 percent are free of detectable disease. We tried to improve these outcomes by treating patients with hepatic arterial infusion of floxuridine plus systemic fluorouracil after liver resection. METHODS: We randomly assigned 156 patients at the time of resection of hepatic metastases from colorectal cancer to receive six cycles of hepatic arterial infusion with floxuridine and dexamethasone plus intravenous fluorouracil, with or without leucovorin, or six weeks of similar systemic therapy alone. Patients were stratified according to previous treatment and the number of liver metastases identified at operation. The study end points were overall survival, survival without recurrence of hepatic metastases, and survival without any metastases at two years. RESULTS: The actuarial rate of overall survival at two years was 86 percent in the group treated with local plus systemic chemotherapy and 72 percent in the group given systemic therapy alone (P=0.03). The median survival was 72.2 months in the combined-therapy group and 59.3 months in the monotherapy group, with a median follow-up of 62.7 months. After two years, the rates of survival free of hepatic recurrence were 90 percent in the monotherapy group and 60 percent in the monotherapy group (P<0.001), and the respective rates of progression-free survival were 57 percent and 42 percent (P=0.07). At two years, the risk ratio for death was 2.34 among patients treated with systemic therapy alone, as compared with patients who received combined therapy (95 percent confidence interval, 1.10 to 4.98; P=0.027), after adjustment for important variables. The rates of adverse effects of at least moderate severity were similar in the two groups, except for a higher frequency of diarrhea and hepatic effects in the combined-therapy group. CONCLUSIONS: For patients who undergo resection of liver metastases from colorectal cancer, postoperative treatment with a combination of hepatic arterial infusion of floxuridine and intravenous fluorouracil improves the outcome at two years.

Adenocarcinoma↗
PubMed1999

Two distinct regions of deletion on chromosome 13q in primary nasopharyngeal carcinoma.

Nasopharyngeal carcinoma (NPC) is rare in most parts of the world, but prevalent in Southern China. Although this disease poses a serious health problem in our population, the genetic alterations that lead to the development of NPC have yet to be defined. In a comparative genomic hybridization (CGH) study on NPC by our group, loss of the long arm of chromosome 13 has been identified as a frequent event. To investigate further the involvement of this genetic alteration in NPC tumorigenesis, we examined 31 primary NPC tumours by LOH analysis with a panel of 13 microsatellite polymorphic markers distributed along the long arm of chromosome 13. It was found that 19/31 tumours (60%) showed LOH for markers on chromosome 13q. The highest frequency of LOH was found at loci D13S133 (53.6%) on 13q14.3 and D13S796 (38.5%) on 13q32-34. Two distinct smallest deletion regions were delineated: the first region between D13S133 and D13S119 at 13q14.3-22, and the second region between D13S317 and D13S285 at 13q31-34. Our findings show that LOH of 13q is a common event in NPC and that at least 2 putative tumour-suppressor loci may be present on 13q. Mapping of the critical regions of these loci suggests that some candidate tumour-suppressor genes on 13q, other than Rb and BRCA2, may be involved in the development of NPC.

BRCA2 Protein↗
PubMed1999

A mammalian severin replaces gelsolin in transformed epithelial cells.

A persisting paradox in cytoskeletal regulation of cell motility is the loss of the actin filament fragmenting protein, gelsolin, in transformed epithelial cells that have gained the ability to migrate. Either actin filament severing does not occur during motility of carcinoma cells or a novel fragmentation protein is expressed during transformation. Using an antibody specific for severin, the Mr 40,000 actin filament severing protein from Dictyostelium discoideum amoebae, we have identified a mammalian form of severin in murine LL/2 carcinoma cells lacking gelsolin. Mammalian severin (M-severin) isolated from LL/2-derived Lewis lung carcinoma tumors severed F-actin in a calcium-dependent manner, mimicking the function of Dictyostelium severin. M-severin preferentially localized to the cleavage furrow of dividing LL/2 cells and to the actin-rich cortex of migratory LL/2 cells, known sites of active actin cytoskeleton rearrangement. The mammalian severing protein was fully expressed in transformed LL/2 epithelial cells but went undetected in normal mouse muscle, liver, spleen, or kidney. Normal mouse lung tissue contained minute amounts of M-severin, attributed to motile cells in pulmonary connective tissue. In striking contrast to M-severin, gelsolin was highly expressed in normal lung but disappeared in transformed LL/2 carcinoma cells. Based on prior observations of a functional role for actin filament fragmentation in cell migration, the simultaneous induction of M-severin and loss of gelsolin during epithelial transformation suggests that replacement of gelsolin by M-severin may function to achieve actin filament rearrangements necessary for active cell migration in invasive or metastatic carcinoma. Induction of M-severin in an invasive tumor was directly observed in human colon adenocarcinoma by cytoimmunohistochemistry with antibodies directed against severin isolated from both Dictyostelium amoebae and Lewis lung carcinoma cells. Because normal colon epithelium from the same patient did not express M-severin, it may serve as a sensitive marker for detection and staging of epithelial tumors.

Adenocarcinoma↗
PubMed1999

Evaluation of chest computed tomography in the staging of patients with potentially resectable liver metastases from colorectal carcinoma.

BACKGROUND: Chest computed tomography (CT) often is used to rule out lung metastases in patients with potentially resectable liver metastases from colorectal carcinoma. In the current study the authors evaluated whether CT of the chest was necessary in patients with a negative chest radiograph. METHODS: The authors performed a retrospective analysis of 202 patients with negative initial chest X-rays who were undergoing evaluation for potentially resectable liver metastases from colorectal carcinoma. Patients with highly suspicious pulmonary lesions on the initial chest CT scan underwent a thoracoscopy and biopsy. All patients were monitored for the development of pulmonary metastases. RESULTS: Sixty patients (30%) had a positive initial chest CT scan. Two patients were found to have metastases by comparison with prior CT scans. Seventeen patients had highly suspicious lesions that were biopsied, but only 2 were found to have pulmonary metastases; the other lesions were benign. An additional 13 of these 60 patients developed lung metastases during follow-up, 6 of whom were diagnosed in retrospect. Of the 142 patients with a negative initial CT scan, 33 (23%) developed pulmonary metastases. The rate of pulmonary metastases in both groups was not significantly different, regardless of whether the CT scans were positive or negative. CONCLUSIONS: During routine preoperative workup for liver resection, the majority of lesions appearing on chest CT scans of patients with negative chest radiographs were not malignant. The positive yield of CT-guided workup was only 10 of 202 patients (5%). Based on this review the authors question the use of chest CT scans in this setting.

Adult↗
PubMed1999

Selective infection and cytolysis of human head and neck squamous cell carcinoma with sparing of normal mucosa by a cytotoxic herpes simplex virus type 1 (G207).

This study evaluates inhibition of human squamous cell carcinomas (SCCs) by a replication-competent multimutated herpes simplex virus type 1 (G207). Infectivity and cytotoxicity of the G207 virus were evaluated in vitro in seven human SCC cell lines. In vivo effects of the G207 virus on human tumor xenografts in an athymic rat model were then investigated by injecting established tumors with 1 x 10(7) virus particles and monitoring tumor growth. In addition, oral cavity tumors in immunocompetent hamster were infected with the G207 virus by selective intraarterial perfusion and the tumor response was monitored. In vitro studies demonstrated infection rates, measured 24 hr after exposure, exceeding 40% at an MOI of 2 in five of seven human SCC cell lines. Cytotoxic effects, as measured by percent cell death on day 5, exceeded 90% in five of seven SCC cell lines. In vivo inhibition of tumor growth in an athymic rat model was seen (p < 0.005) and in two of the cell lines a complete clinical response was seen in 12 of 14 tumors. In the hamster model, selective intraarterial perfusion with G207 virus showed selective infection of the tumor cells, with sparing of the adjacent normal mucosa, which leading to significant suppression of tumor growth (p < 0.005). The G207 virus displayed efficient and selective cytotoxicity and tumor growth inhibition against human SCC and may prove useful as a therapeutic agent for head and neck SCC.

Animals↗
PubMed1999

Specific interaction of Tat with the human but not rodent P-TEFb complex mediates the species-specific Tat activation of HIV-1 transcription.

Tat stimulation of HIV-1 transcriptional elongation is species-specific and is believed to require a specific cellular cofactor present in many human and primate cells but not in nonpermissive rodent cells. Human P-TEFb, composed of Cdk9 and cyclin T1, is a general transcription elongation factor that phosphorylates the C-terminal domain of RNA polymerase II. Previous studies have also implicated P-TEFb as a Tat-specific cellular cofactor and, in particular, human cyclin T1 as responsible for the species-specific Tat activation. To obtain functional evidence in support of these hypotheses, we generated and examined the activities of human-rodent "hybrid" P-TEFb complexes. We found that P-TEFb complexes containing human cyclin T1 complexed with either human or rodent Cdk9 supported Tat transactivation and interacted with the Tat activation domain and the HIV-1 TAR RNA element to form TAR loop-dependent ribonucleoprotein complexes. Although a stable complex containing rodent cyclin T1 and human Cdk9 was capable of phosphorylating CTD and mediating basal HIV-1 elongation, it failed to interact with Tat and to mediate Tat transactivation, indicating that the abilities of P-TEFb to support basal elongation and Tat activation can be separated. Together, our data indicated that the specific interaction of human P-TEFb with Tat/TAR, mostly through cyclin T1, is crucial for P-TEFb to mediate a Tat-specific and species-restricted activation of HIV-1 transcription. Amino acid residues unique to human Cdk9 also contributed partially to the formation of the P-TEFb-Tat-TAR complex. Moreover, the cyclin box of cyclin T1 and its immediate flanking region are largely responsible for the specific P-TEFb-Tat interaction.

Animals↗
PubMed1999

Association of preoperative biliary stenting with increased postoperative infectious complications in proximal cholangiocarcinoma.

BACKGROUND: The indications for preoperative biliary stenting in patients with obstructive jaundice are controversial. We evaluated the effect of preoperative biliary stenting on bacterobilia and infectious complications following surgical treatment of proximal cholangiocarcinoma. DESIGN: A retrospective review was performed of all patients undergoing surgical treatment of proximal cholangiocarcinoma. SETTING: A metropolitan cancer surgery service. PATIENTS AND METHODS: Seventy-one patients underwent palliative biliary bypass or curative resection of proximal cholangiocarcinoma from March 1, 1991, to April 1, 1997, and were entered into a prospective database. Forty-one patients underwent preoperative biliary intubation and stent placement. We analyzed patient, nutritional, laboratory, and operating room factors. Statistical evaluation was performed using Student t test and chi2 analysis. MAIN OUTCOME MEASURE: Data were recorded for a history of cholangitis, operative time, amount of blood loss, incidence of intraoperative bacterobilia, proportion of patients with postoperative infectious and noninfectious complications, and length of hospital stay. RESULTS: All patients (n = 14) with a history of preoperative cholangitis had been subjected to previous endoscopic retrograde cholangiopancreatography and/or percutaneous transhepatic biliary drainage. Groups were equivalent for risk for comorbidity, proportion undergoing curative vs palliative procedures, time spent in the operating room, and amount of blood loss. Patients with stents had a significantly lower bilirubin level (P = .005). Patients with stents had a significantly increased risk for bacterobilia (P = .001) and infectious complications (P = .03). Bacterobilia was present in 11 (100%) of 11 patients undergoing endoscopic stenting and in 15 (65%) of 23 patients undergoing percutaneous stenting. There was no increased risk for noninfectious complications, length of hospital stay, or mortality in patients with stents. In 10 (59%) of 17 patients with postoperative infectious complications and positive findings of intraoperative bile culture, the organism was synonymous. CONCLUSIONS: Preoperative biliary stenting in proximal cholangiocarcinoma increases the incidence of contaminated bile and postoperative infectious complications. Endoscopic stents frequently do not relieve jaundice in high biliary obstruction and are rarely indicated, especially in light of their high contamination rate.

Aged↗
PubMed1999

Comparison of magnetic resonance and endoscopic retrograde cholangiopancreatography in malignant pancreaticobiliary obstruction.

HYPOTHESIS: We hypothesize that magnetic resonance cholangiopancreatography (MRCP) is comparable to endoscopic retrograde cholangiopancreatographic (ERCP) as a diagnostic tool in patients with malignant biliary obstruction. DESIGN: Eighteen patients with suspected pancreaticobiliary malignancy were evaluated by ERCP and MRCP in 8 months (March 1, 1996, to October 31, 1996). Magnetic resonance cholangiopancreatography was performed with a 1.5-T scanner using 4-mm slices. Images were obtained in a 14- to 28-second breath-hold. Images from MRCP were retrospectively evaluated by a radiologist for image quality, ductal dilation, level of obstruction, and overall diagnostic impression. Images from ERCP were retrospectively evaluated by a biliary endoscopist (L.H.S.) and served as the standard for calculating sensitivity, specificity, and positive predictive values. In addition, intraoperative findings were compared with MRCP results in all patients explored. RESULTS: Diagnostic-quality MR images were obtained in 18 patients (100%). Diagnostic-quality endoscopic images were obtained in 16 (89%) of 18 attempted biliary cannulations and 11 (78%) of 14 attempted pancreatic cannulations. Magnetic resonance CP accurately delineated the level of extrahepatic biliary ductal obstruction in 13 (87%) of 15 patients. More important, MRCP provided valuable staging information in most patients. Findings from MRCP correlated with operative findings (size and location of tumor and mesenteric vascular involvement) in 8 (80%) of 10 patients who underwent surgery, while failing in 2 patients (20%) with carcinomatosis. CONCLUSIONS: Magnetic resonance CP is a sensitive study for detecting the presence and level of biliary ductal obstruction in patients with cancer. The results are comparable to those of ERCP; however, MRCP provides additional data regarding extent of disease that is not available from ERCP alone.

Adult↗
PubMed1999

In vivo interleukin-2 gene therapy of established tumors with herpes simplex amplicon vectors.

In vivo cytokine gene transfer may greatly simplify autologous tumor vaccine production. Herpes simplex viral amplicon vectors (HSV) are efficient gene-transfer vehicles and may overcome many limitations of prior gene-transfer methods. The interleukin-2 (IL-2) and beta-galactosidase genes (lac) were inserted into an HSV amplicon vector and tested in a subcutaneous squamous cell carcinoma of lung origin to determine the efficiency of in vivo gene transfer and the utility of such a direct gene transfer approach in cancer therapy. Gene transfer and expression were assessed by histochemical staining and enzyme-linked immunosorbent assay (ELISA). Growth of injected tumors as well as non-injected tumors remote from the site of injection was assessed. Assessment of lymphocytic infiltrates into tumors was performed by immunohistochemistry. Survival was recorded. Direct in vivo injection of established tumors with a HSVi12 resulted in efficient gene transfer and production of IL-2 in the injected tumor but not at tumors remote from the sites of injection. There was a significant suppression of growth of the tumors injected with HSVi12 (P<0.01) when compared with tumors injected with HSV without i12. Of note, growth of tumors remote from sites of HSVi12 injection was also retarded and treatment was associated with a significant (P<0.05) improvement in survival. Direct intratumoral administration of HSV amplicon vectors can result in efficient transfer of cytokine genes and have antitumor efficacy. HSV vectors are therefore potentially useful agents in such in vivo gene-therapy strategies and simplify cytokine antitumor gene-therapy strategies.

Animals↗
PubMed1999

Extended left hepatectomy.

Extended left hepatectomy (resection of Couinaud segments II, III, IV, V, and VIII of the liver) has only slowly been appreciated as a viable resectional technique for large, strategically placed, left-sided and central hepatic lesions that extend to involve the right anterior sectoral portal pedicular structures. We report on the preoperative, intraoperative, and postoperative findings of 51 patients undergoing extended left hepatectomy at Memorial Sloan-Kettering from 1992 to 1998. Median age was 58 years (range 1-85), with 28 males and 23 females. Altogether 34 patients had metastatic hepatic malignancies, 14 had primary hepatic malignancies, and 3 had benign hepatic lesions. Median postoperative length of stay was 10 days (range 6-52). Postoperative morbidity and mortality were 53% and 8%, respectively. Multivariate analysis of multiple preoperative variables disclosed that only the largest hepatic lesion of >8 cm (p = 0.033) was an independent predictor of a positive microscopic margin or tumor within one high power field. No preoperative, intraoperative, or postoperative variables were independent predictors of postoperative morbidity or mortality. Utilization of extended left hepatectomy allows resection of critically positioned hepatic lesions previously thought unresectable. It can be performed relatively safely, although it is not without somewhat increased postoperative morbidity and mortality compared to lesser anatomic hepatic resections. Patient selection, as dictated by factors associated with adequate tumor clearance (tumor size and proximity to the right sectoral portal pedicular structures), may be important for determining appropriate candidates for this aggressive resectional technique.

Adolescent↗
PubMed1999

Estimates of sperm sex chromosome disomy and diploidy rates in a 47,XXY/46,XY mosaic Klinefelter patient.

A 47,XXY/46,XY male was investigated for the incidence of aneuploidy in sperm sex chromosomes using a three-colour X/Y/18 fluorescence in situ hybridisation (FISH) protocol. A total of 1701 sperm nuclei were analysed. The ratio of X-bearing to Y-bearing sperm did not differ from the expected 1:1 ratio although there were more 23,Y sperm than 23,X sperm (844 vs 795). There was a significantly increased proportion of disomy XY and XX sperm compared with normal controls (0.41% vs 0.10%, P < 0.001 and 0.29% vs 0.04%, P < 0.01). However, the incidence of YY sperm was similar to the controls (0.06% vs 0.02%). The diploidy rate was also significantly increased (1.7% vs 0.13%, P < 0.0001), as was disomy 18 (0.71% vs 0.09%) and 25,XXY (0.47% vs 0%). The results support the hypothesis that some 47,XXY cells are able to undergo meiosis and produce mature spermatozoa. Patients with mosaic Klinefelter syndrome with severe oligozoospermia have significantly elevated incidences of disomy XY and XX sperm and may be at a slightly increased risk of producing 47,XXX and 47,XXY offspring. Additionally, they may be at risk of producing offspring with autosomal trisomies. Hence, patients with Klinefelter mosaicism scheduled for intracytoplasmic sperm injection intervention should first undergo FISH analysis of their sperm to determine their risk.

Adult↗
PubMed1999

Utility of 18F-FDG positron emission tomography scanning on selection of patients for resection of hepatic colorectal metastases.

BACKGROUND: Hepatectomy represents a standard and potentially curative therapy for hepatic colorectal metastases. However, up to two thirds of patients explored for resection are found to have unsuspected disease, which precludes resection. METHODS: In order to determine if 18F-FDG positron emission tomography (PET) scanning may prevent unnecessary surgery, a group of 40 patients being considered for hepatic resection but at high risk for unresectable disease by clinical criteria were subjected to whole body 18F-FDG-PET scanning. Effect on clinical outcome was evaluated. In addition, PET findings in the 25 patients who underwent resection of hepatic metastases were directly compared with the resected specimen to determine the sensitivity of 18F-FDG PET scanning in the liver. RESULTS: Findings on 18F-FDG-PET scanning influenced the clinical management in 16 patients (40%) and directly altered management in 9 cases (23%). Six patients were spared laparotomy, and 3 others had PET-directed surgery that found extrahepatic tumor and spared the patient unwarranted liver resection. In 3 cases PET missed peritoneal metastases found on laparotomy. In these cases all missed tumors were less than 1 cm in size. Out of 52 resected hepatic lesions, 18F-FDG-PET detected 37. Within the liver, sensitivity of detection was also related to size. Only 25% of hepatic lesions smaller than 1 cm were detected by PET, while 85% of lesions larger than 1 cm were detected. CONCLUSIONS: FDG-PET is best for detecting extrahepatic disease. There are few false positives, and surgeons should carefully evaluate and biopsy extrahepatic positive sites. This test should be used for patients at high risk for extrahepatic disease and should be evaluated prospectively for all patients under consideration for liver resection.

Adult↗
PubMed1999

Analysis of the sex chromosome constitution of sperm in men with a 47, XYY mosaic karyotype by fluorescence in situ hybridization.

OBJECTIVE: To determine the incidence of sex chromosome aneuploidy in the sperm of two men with a 47,XYY/46,XY karyotype. DESIGN: Case report. SETTING: Infertility clinic in a teaching hospital. PATIENT(S): One patient with near normal semen parameters whose wife had a history of miscarriages and one patient with primary infertility and severe oligoasthenozoospermia. INTERVENTION(S): Cytogenetic analysis of peripheral lymphocytes and three-color X/Y/18 fluorescence in situ hybridization analysis of sperm. MAIN OUTCOME MEASURE(S): Analysis of sex chromosome disomy and diploidy rates in sperm. RESULT(S): Both patients had a 47,XYY/46,XY karyotype. The hyperdiploidy rate of patient 1 was 19% and that of patient 2 was 90%. The incidence of disomy XY was significantly elevated in both patients compared with the controls (0.23% and 1.02%, respectively, versus 0.10%). The incidence of disomy YY (0.44% versus 0.10%) was increased only in patient 2, as was the incidence of disomy 18 (0.49% versus 0.09%) and the rate of diploidy (0.83% versus 0.13%). The rate of 24,XX sperm in both patients was not different from that in the controls. CONCLUSION(S): Patients with a 47,XYY mosaic karyotype may be at risk of producing offspring with a hyperdiploid sex constitution. These patients should have their sperm investigated by fluorescence in situ hybridization to determine their particular risks before they undergo intracytoplasmic sperm injection.

Adult↗
PubMed1999

Particle embolization of hepatic neuroendocrine metastases for control of pain and hormonal symptoms.

PURPOSE: To evaluate treatment outcome with respect to the indication for treatment in patients with neuroendocrine tumors metastatic to the liver undergoing hepatic artery embolization with polyvinyl alcohol (PVA) particles. MATERIALS AND METHODS: Charts and radiographs were reviewed of 35 patients undergoing 63 separate sessions of embolotherapy between January 1993 and July 1997. Patient demographics, tumor type, indication for embolization, and complications were recorded. Symptomatic and morphologic responses to therapy were noted, as well as duration of response. RESULTS: Fourteen men and 21 women underwent embolization of 21 carcinoid and 14 islet cell tumors metastatic to the liver. These patients underwent 63 separate episodes of embolotherapy. Of 48 episodes that could be evaluated, response to treatment was noted following 46 episodes (96%). The duration of response was longest in patients treated for hormonal symptoms with (17.5 months) or without (16 months) pain, and was shortest (6.2 months) when the indication was pain alone. Complications occurred after 11 of the 63 embolizations (17%), including four (6%) deaths. Cumulative 5-year survival following embolotherapy was 54%. CONCLUSION: Hepatic artery embolization with PVA particles is beneficial for patients with neuroendocrine tumors metastatic to the liver and may be used for control of pain as well as hormonal symptoms. This therapy should be used cautiously when more than 75% of the hepatic parenchyma is replaced by tumor.

Adenoma, Islet Cell↗
PubMed1999

Liver resection for metastatic colorectal cancer: assessing the risk of occult irresectable disease.

BACKGROUND: Liver resection is standard therapy for selected patients with metastatic colorectal cancer. Extrahepatic metastases and inability to remove all hepatic disease usually preclude curative resection and are the most common contraindications. This study analyzes irresectability in patients considered to have resectable disease taken to operation for potentially curative hepatic resection. We describe preoperative factors associated with irresectability and propose a preoperative scoring system that identifies patients at particularly high risk for occult irresectable disease. STUDY DESIGN: Patients considered to have resectable hepatic colorectal metastases were identified from a prospective database. Intraoperative findings that precluded liver resection were recorded. Demographic data, characteristics of the primary tumor, and characteristics of the hepatic metastases were recorded and analyzed. RESULTS: From April 1992 through July 1997, 416 patients were explored with the intention of performing a potentially curative liver resection; 329 (79%) were resected. Eighty-seven patients (21%) had apparently resectable tumors on preoperative imaging but irresectable disease at laparotomy. Forty-four patients (51%) had irresectable disease limited to the liver; 32 had extensive bilobar disease not appreciated before surgery, and 12 were not resected for technical or other reasons unrelated to disease extent. Forty-three patients (49%) had extrahepatic disease, 31 of whom had resectable hepatic tumors. Of the several preoperative factors analyzed, only the estimated number of hepatic tumors was an independent predictor of irresectable findings at operation. This held true for patients with extrahepatic metastases and those with extensive hepatic disease. From these data, we devised a preoperative scoring system that estimates the probability of finding occult irresectable disease. Resectability ranged from 95% in patients with a score of 0 (solitary, unilobar) to 62% in those with a score of 3 (multiple, bilobar; p = 0.0001). The predictive value of this scoring system was then validated by applying it prospectively to an additional group of 118 patients taken to surgery for resection; the results were similar. CONCLUSIONS: Standard preoperative investigations predicted resectability in 79% of patients with hepatic colorectal metastases. Unresectable disease limited to the liver and extrahepatic disease were seen with nearly equal frequency. The majority of patients with extrahepatic metastases had resectable hepatic disease (31 of 43, 72%). A preoperative scoring system is proposed that identifies patients at high risk for unrecognized irresectable disease and may help focus the use of additional diagnostic modalities such as laparoscopy and positron emission tomography (PET).

Colorectal Neoplasms↗