Influence of thorax irradiation on the survival of mice with spontaneous or artificial lung metastases from a transplantable mammary adenocarcinoma

The effect of thorax irradiation on lung metastases, either occurring spontaneously from a primary mammary adenocarcinoma (M8013X) transplanted on the leg or artificially induced by intravenous injection of tumor cells was studied. Increasing the interval between the moment at which lung metastases are supposed to originate and the thorax irradiation resulted in a rapid decrease of the effectiveness of this treatment in preventing the development of lung metastases. Early treatment of the mice not only resulted in a considerable number of animals that were cured, but also in a significant decrease in the number of tumor localizations in the lung of those animals still developing metastases. Thorax irradiation performed later was much less effective; at autopsy the lung showed a large number of small metastases. Increasing the radiation dose led to an increased number of cures; however, an increased number of mice dying of lethal lung damage was also observed. Irradiation of the lungs of mice with 5 or 10 Gy, 24 hours, 7 days or 14 days prior to i.v. injection with tumor cells, did not significantly increase the number of mice with lung metastases. Immunological resistance against the tumor played a role in our experiments with both spontaneous and artificial lung metastases.     

Intravenous administration of BCG in advanced melanoma patients

From June 1975 to August 1977, 19 patients with distant metastases of malignant melanoma of the skin that were no longer responsive to chemotherapy were treated with BCG given intravenously. A single dose of lyophilized Pasteur BCG ranging from 2 X 10(7) to 3 X 10(8) viable units was given in 500 ml of saline infused in 5 to 6 h. Seven of the 16 evaluable patients benefited from treatment; 3 showed an objective regression of more than 50% of the original tumor volume, and 4 an arrest of tumor growth. The objective regressions lasted from 2 to 5 months, and 1 case had an arrest of tumor growth for 29 months. The regression rate was related to the BCG dosage: 2 X 10(8) viable units appears to be the dosage that gives severe but reversible toxicity and is able to induce objective regression. The most responsive lesions were skin and subcutaneous deposits (5 of 7) and lung metastases (1 of 4). Toxic effects seem to be related to the number of bacilli injected. In the group of 10 cases treated with less than 10(8) units, toxicity was modest: 4 patients had fever (up to 38.5 degrees C) that lasted a few days, and in 3 cases it was associated with shivering during the infusion period and weakness. One case only had vomiting and jaundice. Toxicity was severe in the 9 patients that were treated with a dosage higher than 10(8): patients had fever and weakness for at least 4 days and shivering during the infusion. Two had adrenal insufficiency and 7 had liver enlargement and jaundice with return to normality by day 21. In the whole series 8 patients had leucopenia and 5 thrombocytopenia for 2 to 3 days: only 1 patient required blood and platelet transfusion. No significant variations in immunoglobulin levels were observed. No variations of PPD or BCG skin tests were observed after treatment. Three patients expired; the first treated with 6 X 10(7) unit, had an intercurrent disease (autopsy showed a heart infarction); the second, treated with 1.8 X 10(8), showed a rapid growth of lung metastases and died 15 days after treatment; the death of the third patient was probably due to anaphylactic shock. All 3 patients had been previously treated with BCG, given by scarification or intranodular injection.     

Serum gamma-glutamyltransferase and alkaline phosphatase during experimental liver metastases. Detection of tumour-specific isoforms and factors affecting their serum levels

Tumour-specific isoenzymes and tumour markers in serum are potentially useful in the detection and monitoring of liver metastases. An experimental rat model was used in the search for such isoenzymes and to study factors affecting their serum levels. Splenic injection of CC531 colon carcinoma cells in syngeneic WagRij rats caused liver metastases after 3 weeks with concomitant and significant increases in serum levels of gamma-glutamyltransferase (GT) and alkaline phosphatase (ALP). The presence of tumour-specific isoforms of both enzymes, as well as increased amounts of the liver isoform of ALP, were demonstrated in serum. The serum levels of the tumour variants were clearly related to their elimination rates from the circulation. Thus, the slow clearance of the tumour ALP resulted in high serum levels of this isoform, compared with the more rapid elimination of tumour GT and its lower serum level. When using another colon carcinoma cell line (DHD/K12), metastatic to liver in BD IX rats, no increases in serum GT were detected. This was related to the rapid elimination from the circulation of the GT variant from the DHD/K12 metastatic tissue. The relatively high amount of the tumour ALP isoform detected in serum during growth of the CC531 liver metastases indicated that this isoform could be useful as a marker of tumour growth.     

The infiltration of experimentally induced lung metastases of colon carcinoma CC531 by adoptively transferred interleukin-2-activated natural killer cells in wag rats

The number of IL-2-activated natural killer (A-NK) cells reaching the tumor site in vivo may be crucial for their antitumor effect following adoptive immunotherapy. We investigated in a syngeneic rat model the infiltration of established lung metastases by adoptively transferred A-NK cells. The Wag rat colon carcinoma CC531 was injected via a tail vein to induce pulmonary metastases. Syngeneic A-NK cells were labeled with the fluorescent dye rhodamine (TRITC) and next injected via a tail vein in rats bearing day-12 lung tumors. The number of A-NK cells in tumor and in normal tissue per rat was counted in sections after administration of A-NK cells. At all time points tested, a significant linear relationship between the cross-section area of the tumor and the number of infiltrating cells was observed, but small tumor areas became fully infiltrated earlier than larger areas. At 24 hr after injection, approximately 10% of the injected cells were found in the tumor tissue and the average A-NK-cell-to-tumor-cell ratio was estimated to be 1:3. A-NK cells were found in the liver too, although the number of cells per mm² tissue was low compared with the pulmonary tumor tissue. Very low numbers of A-NK cells were found in kidney, adrenal gland, spleen, and blood. We conclude that, in this syngeneic rat model, adoptively transferred A-NK cells are able to find and specifically infiltrate pulmonary metastases in a time-dependent fashion.     

Liver metastasis of colon 26 cells implanted into the superior mesenteric vein in mice

The intraportal implantation of mouse transplantable colon adenocarcinoma 26 was investigated as an experimental liver metastasis model of colorectal cancer. CDF1 male mice (5 weeks old) were laparotomized under pentobarbital sodium anesthesia, and colon 26 tumor cells (1 X 10, 1 X 10(3), or 1 X 10(5) cells) were inoculated into the superior mesenteric vein. On day 21 after inoculation, mice inoculated with 1 X 10(3) tumor cells showed five to 12 colonies of liver metastasis (mean, 9.2 colonies; n = 6). The survival time was 27 to 36 days (median, 27 days; n = 5) in these mice. When mitomycin C (MMC) was administered into the superior mesenteric vein 15 min after the inoculation of tumor cells, the number of metastatic foci in the liver was strongly inhibited; 81.1% and 100% inhibitions were observed in the groups given 4 mg/kg and 6 mg/kg of MMC, respectively. The mouse colon 26 model seems to be one of the more useful experimental models for evaluating treatments for the prevention of liver metastases from colorectal cancer.     

Spleen migrating dendritic cells primed with CC531 colon cancer antigen and LPS – is it a method to compromise liver metastases?

The anti-tumor vaccination is burdened by low recruitment rate of intravenously administered in vitro primed DC in liver metastases and lack of supplying them continuously in large numbers. Therefore, it seemed rational to create a model of in vivo vaccination with specifically primed splenic DC and cytotoxic T lymphocytes being continuously supplied to the liver vascular bed. The question we raised was whether anti-tumor immunized splenic DC flowing to liver metastases could adhere to and be cytotoxic to tumor cells. We immunized rats with CC531 tumor cells and stimulated them with Escherichia coli LPS. Subsequently, spleen DC-enriched population was isolated, its activation by LPS, adherence to CC531 cells and cytotoxicity were measured. Spleen cells home to the liver reaching it via splenic vein. These cells can be retrieved by simple washout of liver sinusoids (liver sinusoidal washout cells – LSWC). Their adherence to and cytotoxicity against CC531 cells were evaluated. Moreover, in vitro adherence of splenic DC-enriched cells and LSWC to CC531 liver tumor sections was measured. We found that in vivo immunization of splenic population containing DC, NK cells and lymphocytes with CC531 cells and stimulation with LPS activated these cells but did not significantly increase the cytotoxicity against CC531 cells. There was also no increase in cytotoxicity of LSWC. Adhesion of splenic DC and LWSC to liver CC531 metastases on cryosections was higher than to the adjacent liver tissue. However, it was more expressed on tumor stromal than neoplastic cells. The level of splenic Treg cells down-regulating immune response was found only slightly increased after immunization. Taken together, in the model of in vivo immunization against CC531 cells, low level of spleen DC and spleen-derived LSWC cytotoxicity as well as adherence rate to tumor cells were observed. More effective methods of immunizing splenic DC overcoming the suppressive mechanisms should be looked for.     

Celecoxib inhibits growth of tumors in a syngeneic rat liver metastases model for colorectal cancer

INTRODUCTION: Nonsteroidal anti-inflammatory drugs (NSAIDs) have been shown to reduce the risk of colorectal cancer in cyclooxygenase-2 (COX-2) overexpressing colorectal cancers. The present study was designed to evaluate the inhibitory effects of the COX-2 inhibitor celecoxib on the growth of colorectal cancer liver metastases in a syngeneic rat model, CC531. MATERIALS AND METHODS: The effects of celecoxib on cell viability in vitro were evaluated by treatment of CC531 tumor cell cultures with celecoxib. In vivo, Wag/Rij rats were inoculated with CC531 tumor cells at two sites in the liver and treated with celecoxib starting one week before, or directly after tumor inoculation. Control rats were inoculated without treatment. Three weeks after tumor inoculation rats were sacrificed. Tumor size, immune cell infiltration, caspase-3 activity, PGE(2) and celecoxib levels were determined. RESULTS: CC531 tumors did not show COX-2 expression. Tumor growth was significantly inhibited by celecoxib treatment in a dose dependent manner. Immune cell infiltration was decreased after celecoxib treatment, indicating that the immune system was not involved in preventing tumor growth. Tumor caspase-3 levels were only significantly increased if treatment was started before tumor inoculation. Celecoxib serum concentration starting at 0.84 mug/ml significantly inhibited the outgrowth of CC531 liver tumors. In contrast, in vitro concentrations of celecoxib of at least 12 mug/ml were needed to affect tumor cell viability. CONCLUSION: These results suggest that the inhibitory effects of celecoxib on tumor growth are not by direct cytotoxicity, but by creating an unfavorable environment for tumor growth.     

Disrupted expression of CXCL5 in colorectal cancer is associated with rapid tumor formation in rats and poor prognosis in patients.

PURPOSE: We isolated a subline (CC531M) from the CC531S rat colon carcinoma cell line, which grows and metastasizes much more rapidly than CC531S. We found, using RNA expression profiling, that one of the major changes in the CC531M cell line was a 5.8-fold reduction of the chemokine CXCL5. The purpose of this study was to determine the effect of CXCL5 expression on colorectal tumor growth and metastasis. EXPERIMENTAL DESIGN: CC531 clones were generated with either knockdown or restored expression of CXCL5. These clones were inoculated in the liver of rats. In addition, in two independent cohorts of colorectal cancer patients, the level of CXCL5 expression was determined and associated to clinical variables. RESULTS: Knockdown of CXCL5 expression in CC531S resulted in rapid tumor growth and increased number of metastasis, whereas restored expression of CXCL5 in CC531M resulted in a return of the "mild" tumor growth pattern of the parental cell line CC531S. In vitro, no difference was found in proliferation rate between clones with either high or low expression of CXCL5, suggesting that environmental interactions directed by CXCL5 determine tumor outgrowth. Finally, the importance of our findings was established for patients with colorectal cancer. We found that low expression of CXCL5 was significantly associated with poor prognosis for colorectal cancer patients. CXCL5 showed a trend (P = 0.05) for a positive correlation with intratumoral CD8(+) T-cell infiltration, suggesting a possible explanation for the observed poorer prognosis. CONCLUSIONS: Our results show that CXCL5 is important in growth and development of colorectal cancer, implicating a future role in both cancer therapy and diagnosis.     

Evidence for involvement of B lymphocytes in the surveillance of lung metastasis in the rat

These studies examined the composition of lymphocytes within the lung after the introduction of tumor cells that metastasize to the lung in rats. i.v. delivery of MADB106 tumor cells into syngeneic Fischer 344 rats caused dose- and time-dependent development of lung tumors, with surface metastases evident 7 days after injection and markedly increased 11 days after injection. The total number of lymphocytes recovered from the lung was increased 11 days after injection but not 7 days after injection. When lymphocytes from the lung, spleen, and blood were subjected to fluorescence-activated cell sorting analysis, the most conspicuous change was an increase in the percentage of CD45RA+ cells (i.e., B lymphocytes in the rat) in the lung, with no changes seen in the percentage of natural killer (NKR-P1+), CD4+, or CD8+ cells in the lung. Analysis of the time course showed that B lymphocytes increased in the lung soon after i.v. tumor injection, with an initial peak seen 6 h after injection. Rapid influx of B lymphocytes into lung after i.v. tumor cell injection was also observed in another syngeneic tumor model, i.e., after injection of CC531 cells into WAG rats. To determine whether the influx of B lymphocytes into the lung might participate in tumor surveillance, a high dose of antibody (100 microg) to rat B lymphocytes was given to immunoneutralize these cells; this produced an increase in lung tumors in both models. Finally, Fischer 344 rats were given a s.c. injection of MADB106 tumor cells that made them resistant to lung tumors when given a later i.v. injection of these tumor cells. These animals were found to have an elevated level of B lymphocytes residing in the lung associated with the resistance to lung tumor. These findings suggest that early responses of B lymphocytes are important in protection against tumor development in two rat models of cancer.     

Prophylactic therapy for liver metastasis of gastrointestinal carcinomas using biological response modifiers (BRM): fundamental studies on the inhibition of experimental liver metastasis by intraportal administration of OK-432

For prophylactic therapy to inhibit hepatic metastatic recurrence after surgical treatment of gastro-intestinal carcinomas, the effects of OK-432, a biological response modifier (BRM), were examined with inoculation of tumor cells and administration of OK-432 via portal vein. Experiments with the inhibition of liver metastasis were performed as follows. The animals were divided into five groups. Group 1: 1.0 KE of OK-432 was given intraportally 5 minutes after injection of 5.0 X 10(6) tumor cells per rat via the portal vein. Group 2: Non-medicated group, only 5.0 X 10(6) tumor cells per rat were injected into portal vein, as the control for group 1. Group 3: 0.5 KE of OK-432 and 2.5 X 10(6) tumor cells per rat were used. Group 4: 1.0 KE of OK-432 and 2.5 X 10(6) tumor cells were used. Group 5: Non-medicated group, injected with 2.5 X 10(6) tumor cells as the control group for groups 3 and 4. Colonies of metastases in the liver of each group were examined by autopsy on the 30th day after treatment. Metastases were observed in 75% of group 1, 100% of group 2, 58.8% of group 3, 64.3% of group 4 and in 90% of group 5. For the investigation of the mechanisms to inhibit these liver metastases, 51Cr labeled AH60C tumor cells were injected into the portal vein, and the remained of radioactivity in rat liver was examined. The result showed that OK-432 injected into the portal vein did not directly kill the lodging tumor cells. To prove the morphological evidence of inhibition of hepatic metastasis, the changes of tumor cells were microscopically observed.(ABSTRACT TRUNCATED AT 250 WORDS)     

The site of injection of tumor cells in rats does not influence the subsequent distribution of metastases

Our goal was to examine the influence of circulatory anatomy on the development of metastases. We compared the dissemination of tumor cells to different tissues at different stages in both an orthotopic and a heterotopic model of colon cancer in the rat. We used DHD/K12-PROb cells and two groups of BD-IX rats: group O (orthotopic), in which tumors were implanted by intramural injection of the cecum; and group H (heterotopic), in which cells were injected subcutaneously into the thoracic wall. Animals were assigned randomly to one of nine subgroups of each group in terms of the time between the injection of cells and euthanasia (from the third to the twelfth week). The presence of lung or liver macrometastases was recorded and tumor DNA was detected in lung and liver samples from all animals. We found that lung metastases developed in rats in groups O and H, but no metastases were found in liver parenchymas. The rates of detection of tumor DNA in lung and in liver samples were similar in the two groups. Our results suggest that the site of inoculation of DHD/K12-PROb cells did not influence the pattern of development of metastases. This does not support the proposed role of the circulatory anatomy in the distribution of metastases.     

In situ cancer vaccination with a replication-conditional HSV for the treatment of liver metastasis of colon cancer

In this study, we investigated the therapeutic efficacy of a replication-conditional mutant HSV, G207, for the treatment of liver metastasis of colon carcinoma. Three liver metastasis models in syngeneic BALB/c mice were developed: (i) splenic injection, (ii) splenic and subcutaneous (s.c.) injection, and (iii) orthotopic implantation of CT26 colon carcinoma. In the splenic injection model, G207 was injected into the established splenic tumor on day 7. In the splenic and s.c. injection model, G207 were injected into the established s.c. tumor on days 5 and 8. In the orthotopic implantation model, a piece of CT26 tumor tissue was transplanted onto the wall of the cecum and G207 was injected in the established cecum tumor on day 7. On day 21 or 28, animals were sacrificed and liver metastases were evaluated. In all three models in immunocompetent mice, liver metastases were significantly reduced by intratumoral inoculation with G207 compared to the control. In athymic mice, however, there was no significant therapeutic effect of intratumoral inoculation with G207 on liver metastases. Tumor-specific cytotoxic T-lymphocyte responses were induced in mice treated with G207 in the orthotopic implantation model. These results suggest that intratumoral inoculation of G207, as an in situ cancer vaccine, can be an effective approach against liver metastasis of colon cancer and the efficacy involves tumor-specific T-cell responses.     

Characterization of the tumorigenic and metastatic potential of a poorly differentiated human colon cancer cell line

We characterized the tumorigenic and metastatic potential of a poorly differentiated, non-CEA-producing colon cancer cell line, MIP-101, after injection at different sites in athymic mice. After subcutaneous and intrasplenic injection tumor grew locally in 100 and 50%, respectively, but no metastases were found, even after intravenous injection. Intraperitoneal implantation, however, resulted in a high tumor take (10/10) and subsequent liver colonization (8/10 mice). Exogenous CEA prior to intrasplenic injection induced metastasis in 7/8 mice (in 2 mice to the liver and in 5 mice to the lung). Intrasplenic injection of CX-1, a good CEA producer, resulted in hepatic metastases in 100% of the animals. These data suggest a direct or indirect role of CEA in the metastatic process. We conclude that MIP-101 has a high tumorigenic and invasive potential but a low metastatic proclivity, except when grown in the peritoneum, and that pretreatment of tumor-bearing animals with CEA affects the metastatic proclivity.     

Experimental cancer chemotherapy using A liver metastatic model of human colon cancer transplanted into the spleen of severe combined immunodeficient mice

We have developed a liver metastatic model of human colon cancer using severe combined immunodeficient (SCID) mice. Liver metastases were observed in all the SCID mice on day 28 after intrasplenic injection with 5 × 10⁶ dissociated tumor cells of COL-2-JCK, a human colon cancer strain serially transplanted in nude mice. When this model was applied for chemotherapeutic experiments, 5-fluorouracil (5-FU) demonstrated significant antitumor effects in preventing liver metastases, whereas the efficacy of 5-FU was limited in the currently used sc-ip chemosensitivity assay in nude mice. When the human LDH-5 isozyme was evaluated in the homogenized metastatic liver tissue of SCID mice, a good correlation was obtained between the liver tumor weights and LDH-5 isozyme, suggesting that it could be a promising quantitative indicator for metastases. This model would be useful for further studies on the treatment of liver metastases of colon cancer. © 1993 Wiley-Liss, Inc.     

Treatment of liver metastases from colon carcinoma with autologous tumor vaccine expressing granulocyte-macrophage colony-stimulating factor

BACKGROUND AND OBJECTIVES: In preclinical studies, tumor cells genetically altered to secrete granulocyte-macrophage colony-stimulating factor (GM-CSF) can generate systemic antitumor immunity. Clinically relevant immunotherapeutic approaches for the treatment of colorectal cancer should address efficacy within the liver, a common site of metastatic disease. We investigated the effect of irradiated colon cancer cells engineered to produce GM-CSF on protecting from and treating established liver metastases. METHODS: Using a model of liver metastasis by intrahepatic injection of CT-26 murine colon carcinoma cells in syngeneic BALB/c mice, GM-CSF-producing irradiated cells were given as an intradermal vaccine either 14 days prior to hepatic challenge or in animals with early established tumor (days 5 and 10). The presence of tumor, tumor volume, and survival were endpoint determinants. RESULTS: Animals receiving GM-CSF-producing vaccination demonstrated significant protection from subsequent hepatic challenge of viable tumor cells, even at the highest challenge doses. In animals with early established tumors, a significant response was seen with prolongation in survival. CONCLUSIONS: We conclude that GM-CSF autologous tumor vaccination was effective for the treatment of hepatic colorectal metastases in this murine model. These findings provide support for immunotherapeutic approaches for metastatic liver cancer.     

Inhibitory effect of somatostatin analogue RC-160 on the growth of hepatic metastases of colon cancer in rats: a study with magnetic resonance imaging.

The effect of somatostatin analogue RC-160 on the growth of hepatic metastases of colon cancer was investigated in rats using magnetic resonance imaging. Experimental liver metastatic tumors were established in syngeneic BDIX rats after intrasplenic injection of DHD/K12 colon adenocarcinoma cells. Each rat with implanted liver tumors received s.c. injections of somatostatin analogue RC-160 (50 micrograms/kg) or the vehicle (control) twice a day for 4 weeks, starting 3 weeks after tumor inoculation. During the treatment with RC-160, the growth of liver tumors was studied quantitatively by measuring liver tumor volumes in vivo with magnetic resonance imaging at intervals of 7 days. Chronic administration of RC-160 inhibited the growth of hepatic metastases of colon cancer in rats. Significant inhibition of liver tumor growth in RC-160-treated rats was observed throughout the treatment. The final liver tumor volume in the treated rats was decreased by 56.1% as compared to the controls. The treatment with RC-160 reduced the percentage increase in liver tumor volume from 1575 +/- 674% (mean +/- SEM) for the control to 1034 +/- 727% in the treated group. The tumor volume doubling time in treated rats was 3.7 days longer than the controls. The liver tumor growth delay time was 15.1 days. At the end of the treatment, the incidence of ascites and the weights of tumorous livers were also decreased by RC-160 treatment. Administration of RC-160 prolonged the median survival time by 13 days in treated rats. In cell cultures, significant inhibitory effects of somatostatin-14 and RC-160 on the growth of DHD/K12 colon cancer cells were determined by MTT assay and [3H]-thymidine incorporation assay, indicating direct effects of these peptides on the growth of colon cancer cells in vitro. These data suggest that administration of RC-160 could inhibit the growth of colon cancer and their hepatic metastases in rats. Somatostatin analogue RC-160 might be considered as a potential new agent for the treatment of patients with hepatic metastases of colorectal cancers.     

A study of the effect of papaverine in neuroblastoma using the experimental C1300 murine system

The effect of papaverine on transplantable C1300 murine neuroblastoma model was evaluated. Subcutaneous inoculation of A/J mice with 10(6) C1300 cells resulted in predictable tumor growth and animal death in 36 +/- 5 days. In 33% of control animals, lung and liver metastases were observed. Subcutaneous injections of papaverine prior to tumor inoculation and during the tumor growth failed to show any detectable effect on local growth of the tumor. Benign transformation of the primary tumor was not observed. However, papaverine injection 21 days after tumor inoculation was associated with only 9% incidence of metastatic development. Papaverine treatment, when started one day prior to tumor inoculation or 10 days after tumor implant, resulted in complete prevention of all detectable metastatic growth, while having no apparent effect on local tumor growth. Further study of papaverine effect in the neuroblastoma murine model is indicated.     

Chemoembolization of the lung improves tumor control in a rat model.

PURPOSE: The novel method of organ-specific drug application we present here is unilateral chemoembolization of the lung by injecting the pulmonary artery with degradable starch microspheres and cytotoxic drugs to improve tumor control in lung metastases. EXPERIMENTAL DESIGN: In a solitary metastasis rat model (CC531 adenocarcinoma), we studied the clinical and histological tumor response as well as subacute toxicity of the lung. Fourteen days after tumor induction, animals were randomized into five groups. Groups I and II served as controls. Group III received carboplatin i.v. (45 mg/kg). Isolated lung perfusion with buffered starch solution and carboplatin (15 mg/kg) was installed in group IV. Chemoembolization with carboplatin (15 mg/kg) was performed in group V. RESULTS: Seven days later, the difference in the tumor volume before and after treatment was +422 mm(3) (+/-226) in group I, +697 mm(3) (+/-423) in group II, +70 mm(3) (+/-31) in group III, -8 mm(3) (+/-17) in group IV, and -17 mm(3) (+/-16) in group V (P < 0.05 groups IV and V versus groups I, II, and III). No pleural spread was observed in groups IV and V. Histologically, the area of tumor necrosis was largest in group IV. Mild alveolar cell hyperplasia, pulmonary edema, and hemorrhage without subacute fibrotic changes were noted in all groups. CONCLUSION: This is the first study to perform chemoembolization of the lung. Compared with i.v. therapy, chemoembolization was more effective without serious toxicity. Its efficacy was comparable with that of isolated lung perfusion but less stressful for a possible clinical application.     

An orthotopic mouse model of remetastasis of human colon cancer liver metastasis.

Whether liver metastases from colon cancer are capable of metastasizing to other sites is an important question in surgical oncology. To answer this question, we have developed a highly metastatic orthotopic transplant model of a liver metastasis from a human colon cancer patient in nude mice that targets the liver and lymph nodes. The metastatic human tumor was transplanted in athymic nude mice by surgical orthotopic implantation (SOI) of a liver metastasis from a colon cancer patient. The human colon tumor was then subsequently implanted in the colon by SOI or, in an additional series of nude mice, in the liver by surgical hepatic implantation (SHI). The mice were then explored over time for lymph node involvement beginning 10 days after implantation. After SOI, 100% of the animals had liver metastasis within 10 days, and subsequently, 19 days after SOI, all lymph nodes draining the liver were involved with metastasis without any retroperitoneal or lung tissue involvement. After SHI, all sites of lymphatic drainage of the liver, including portal, celiac, and mediastinal lymph nodes, were massively involved by metastasis in 100% of the animals as early as 10 days after tumor implantation on the liver. The results of this study demonstrate that liver metastases from colon cancer are capable of remetastasizing to other sites. This study thus suggests that in colon cancer patients with liver metastasis, mediastinal, celiac, and portal lymph node metastases originate from the liver metastasis and not, as previously thought, from primary colon cancer.     

Hepatocellular carcinoma with tumor thrombus in the portal and hepatic veins treated successfully with hepatectomy and chemotherapy--a case report

A 39-year-old woman was admitted to our hospital because of advanced hepatocellular carcinoma. She had good liver function with clinical Stage I. Abdominal ultrasonographic study and CT scan revealed a huge tumor of 12 cm in diameter in the left lobe of the liver, with tumor thrombi in the portal and hepatic veins. A chest CT scan demonstrated multiple bilateral lung metastases from 5 to 10 mm in size. An extended left hemihepatectomy with extirpation of the portal and hepatic venous tumor thrombi was performed. On postoperative day 7, low-dose cisplatin (10 mg/day-5 days/week) and 5-fluorouracil (250 mg/day-continuous for 7 days/week) were administered intravenously. Four weeks after chemotherapy, CT scan revealed no recurrence in the liver and no change in the lung metastases. The patient is now being treated on an outpatient basis with no change in the metastatic tumors.