Faculty Bibliography

The management of pulmonary metastases remains controversial. More information is available, however, on outcomes in larger series of patients undergoing metastasectomy as well as the indications for the procedure. The role of video-assisted thoracic surgery for the diagnosis and management of these patients is being scrutinized carefully. Isolated perfusion techniques for treating patients with unresectable pulmonary metastases have been applied in phase I and II trials at selected institutions. More data regarding clinical outcomes are necessary, however, before widespread adaptation of this experimental form of treatment is accepted as standard practice

Previous reports of the association of extensive debrisoquine metabolism, controlled by the cytochrome P450 CYP2D6, with increased lung cancer risk have been conflicting. We examined the hypothesis that genetic polymorphism at the CYP2D6 locus identifies individuals at increased risk for lung cancer in a case-control study of 98 incident Caucasian lung cancer patients and 110 age-, race-, and sex-matched controls conducted at the National Naval Medical Center, Bethesda, MD. Using germ line DNA, we identified inactivating mutations at the CYP2D6 locus (CYP2D6*3, CYP2D6*4, CYP2D6*5, and CYP2D6*6A), as well as those mutations that impair but do not abolish enzyme activity (CYP2D6*9 and CYP2D6*10A). Compared to subjects with homozygous inactivating mutations, no association with lung cancer was observed for those with homozygous or heterozygous functional alleles (odds ratios were 0.4 and 0.7, respectively). Furthermore, no excess risk was seen in any histological group or smoking category, and adjustment for smoking and sociodemographic characteristics did not alter the findings. Although the concept that genetic polymorphisms may contribute to differential lung cancer susceptibility is sound, these data do not support the role of CYP2D6 as a marker for elevated lung cancer risk

BACKGROUND: Hyperthermic, isolated pulmonary perfusion with tumor necrosis factor is a surgical procedure that isolates the pulmonary vasculature from the systemic circulation in patients with unresectable primary or metastatic disease confined to the chest. High drug levels are delivered to the perfused organ, avoiding systemic toxicity, and preventing loss of active drug through metabolism. METHODS: The pharmacokinetics of fentanyl are evaluated in three patients while the operative lung is hyperthermic, ventilated, and perfused with an asanguineous solution during nonpulsatile bypass. A loading dose of fentanyl, 1.5 microg/kg to 2.5 microg/kg, was given during the induction of anesthesia followed by a continuous infusion of 150 microg/hr. RESULTS: Results showed no difference in mean plasma fentanyl concentrations before, during, or after bypass and was consistent with clearance values previously reported in healthy adult surgical patients in the absence of an extracorporeal circuit. CONCLUSIONS: Adjustments in fentanyl dosing are not required before, during, or after hyperthermic, isolated pulmonary perfusion is established and a steady state of fentanyl is achieved

Metastasis is highly organized and organ selective, a process involving multiple sequential steps. It occurs through complex interactions between tumor cells and the host. The surviving metastatic cells have heterogeneous biologic and antigenic or immunogenic properties, and the metastatic cells take over the homeostatic mechanisms of the host. Investigations at the genetic level are necessary to make advances in the early diagnosis, treatment, and prevention of metastatic disease

OBJECTIVES: Our objective was to analyze the impact of preoperative and postresection solid tumor volumes on outcomes in 47 of 48 consecutive patients undergoing resection for malignant pleural mesothelioma who were treated prospectively and randomized to photodynamic therapy or no photodynamic therapy. METHODS: From July 1993 to June 1996, 48 patients with malignant pleural mesothelioma had cytoreductive debulking to 5 mm or less residual tumor by extrapleural pneumonectomy (n = 25) or pleurectomy/decortication (n = 23). Three-dimensional computed tomographic reconstructions of preresection and postresection solid tumor were prospectively performed and the disease was staged postoperatively according to the new International Mesothelioma Interest Group staging. RESULTS: Median survival for all patients is 14.4 months (extrapleural pneumonectomy, 11 months; pleurectomy/decortication, 22 months; p2 = 0.07). Median survival for preoperative volume less than 100 was 22 months versus 11 months if more than 100 cc, p2 = 0.03. Median survival for postoperative volume less than 9 cc was 25 months versus 9 months if more than 9 cc, p2 = 0.0002. Thirty-two of forty-seven (68%) had positive N1 or N2 nodes. Tumor volumes associated with negative nodes were significantly smaller (median 51 cc) than those with positive nodes (median 166 cc, p2 = 0.01). Progressively higher stage was associated with higher median preoperative volume: stage I, 4 cc; stage II, 94 cc; stage III, 143 cc; stage IV, 505 cc; p2 = 0.007 for stage I versus II versus III versus IV. Patients with preoperative tumor volumes greater than 52 cc had shorter progression-free intervals (8 months) than those 51 cc or less (11 months; p2 = 0.02). CONCLUSIONS: Preresection tumor volume is representative of T status in malignant pleural mesothelioma and can predict overall and progression-free survival, as well as postoperative stage. Large volumes are associated with nodal spread, and postresection residual tumor burden may predict outcome

PURPOSE: To determine the maximum-tolerated dose (MTD) and dose-limiting toxicities of paclitaxel with concurrent thoracic irradiation in patients with malignant pleural mesothelioma and locally advanced non-small-cell lung cancer (NSCLC) using a 120-hour continuous infusion regimen. A secondary objective was to assess the effect of paclitaxel on the cell cycle through serial tumor biopsies. PATIENTS AND METHODS: Paclitaxel was administered as a 120-hour (5-day) continuous infusion repeated every 3 weeks during the course of radiation therapy. The starting dose of paclitaxel was 90 mg/m2. Doses were escalated at 15-mg/m2 increments in successive cohorts of three patients. In NSCLC patients, radiation was delivered to the primary tumor and regional lymph nodes for a total tumor dose of 6,120 cGy. In mesothelioma patients, hemithoracic irradiation was delivered as the initial treatment field with a conedown to the tumor volume for a total dose of 5,760 to 6,300 cGy. Tumor biopsies were obtained, if possible, before and during paclitaxel treatment. RESULTS: Thirty patients were entered onto this study through three dose levels (from 90 mg/m2 to 120 mg/m2). The MTD was determined to be 105 mg/m2. The dose-limiting toxicity was grade 4 neutropenia (two patients). Grade 2 gastrointestinal (GI) toxicity (nausea and vomiting) was also observed at 120 mg/m2. Three of 30 patients developed a hypersensitivity reaction. Six patients had grade 2 lung injury manifested by a persistent cough that required antitussives. Five patients underwent tumor biopsies. None of the patients showed a significant block of cells in mitosis (G2/M) after paclitaxel infusion. CONCLUSION: The MTD of paclitaxel, when administered as a 120-hour continuous infusion with concurrent radiotherapy, was determined to be 105 mg/m2. The dose-limiting toxicity was neutropenia. Continuous infusion paclitaxel administered with large field irradiation of the lung is well tolerated and deserves continued evaluation

Various vaccination strategies were compared for their ability to elicit antigen-specific tumour immunity, using the SV40-BALB/c murine tumour system. Specifically, mice were injected with baculovirus-derived recombinant SV40 Tag (rTag), synthetic peptides corresponding to B cell epitopes on SV40 Tag or a plasmid DNA construct encoding the gene for SV40 Tag. In vivo tumour immunity was determined by a lethal tumour challenge with syngeneic SV40-transformed tumour cells. SV40 Tag-specific antibody titres were induced in mice immunized with rTag or Tag synthetic peptides. Partial tumour protection was observed in mice that were immunized with SV40 Tag peptides, where as complete tumour immunity was observed in mice immunized with rTag. Although protective tumour immunity was also observed in mice immunized with DNA, negligible levels of antibodies to SV40 Tag were detected. Examination of the cytotoxic T lymphocyte (CTL) activity in mice injected with the SV40 Tag-DNA construct revealed Tag-specific lysis of syngeneic SV40-transformed tumour cells. Conversely, little to no CTL activity was detected in mice immunized with rTag. However, antigen-specific antibodies from rTag immunized mice were capable of mediating antibody-dependent cell-mediated cytotoxicity against SV40-transformed cells. These data indicate that the immune mechanisms elicited for protection against SV40 induced tumours in mice appeared to be dependent on the vaccination strategy employed and included both humoral and cell-mediated immune responses

We have evaluated the effect of antisense IGF receptor transcripts on the proliferation and tumorigenicity in an SV40-induced, immunocompetent hamster mesothelioma model (H9A). Expression of IGF-1 and IGF-1 receptor (IGF-1 R) genes was identified from H9A RNA using RT-PCR and Northern blot analysis. H9A cells were electroporated with inducible expression vectors (under the transcriptional control of heat shock promotor HSP70) containing a cDNA fragment corresponding to bp 1-309 of IGF-1 R in the sense or antisense orientation to generate the respective clones A3 sense or B9 antisense. At 39 degrees C, the B9 antisense transfectants demonstrated significantly less proliferation than A3 sense transfectants (p2 < 0.02). At 34 degrees C, cell growth of A3 sense and B9 antisense transfected cells was not significantly different. The A3 sense clones resulted in greater numbers of tumours in vivo compared to the B9 antisense clone (p2 = 0.0001). The inhibitory effect of IGF-1R antisense transcripts on hamster mesothelioma demonstrated in this study by decreased growth and tumorigenicity in vitro and in vivo may have implications for the therapy of human mesothelioma

Simian virus 40 (SV40) is a DNA tumour virus which is highly oncogenic in hamsters. Only specific histologic types of tumours develop in hamsters injected with SV40, and these are influenced by the route of virus inoculation. When SV40 is injected systemically to expose most different cell types to the virus, the animals develop mesotheliomas, osteosarcomas, sarcomas, and lymphomas within six months. When the virus is injected subcutaneously, sarcomas at the site of injection develop. If hamsters are injected intracranially with SV40, they develop ependymomas. These same tumour types have been found to contain SV40

Pleural mesotheliomas and osteosarcomas develop in hamsters injected intracardially with SV40. Using primers specific for the RB-pocket binding domain of SV40 we analysed with the polymerase chain reaction frozen specimens from 48 human mesotheliomas and 145 human bone tumours. We found that 60% of human mesotheliomas and 33% of human bone tumours contained SV40-like DNA. Immunostaining, Western blot and RNA in situ hybridization experiments revealed SV40 Tag expression in human mesotheliomas. Osteosarcomas were not studied for Tag expression because not enough material was available. Finally, antibodies anti-Tag were detected in the sera collected from patients with mesothelioma. These data indicate that SV40, or a closely related virus, is/are present in human mesothelioma and osteosarcoma