Pulmonary function changes following helical tomotherapy in patients with inoperable, locally advanced non-small cell lung cancer.

PURPOSE: To evaluate alterations in pulmonary function indices after helical tomotherapy and explore potential associations with biologically corrected dosimetric parameters. PATIENTS AND METHODS: In 64 patients with inoperable locally advanced non-small cell lung cancer, pulmonary function tests before and within 6 months after radiotherapy were evaluated retrospectively. In the case of concurrent chemotherapy a total dose of 67.2 Gy was delivered, otherwise 70.5 Gy was provided. In 44 patients, late pulmonary function changes (≥6 months after radiotherapy) could also be assessed. RESULTS: In the entire patient group, there were significant declines in forced expiratory volume in 1s (FEV1) (average change -4.1% predicted; P = 0.007), in forced vital capacity (FVC) (-4.9% predicted; P = 0.002), total lung capacity (TLC) (-5.8% predicted; P = 0.0016) and DLCO (diffusing capacity of the lung for carbon monoxide corrected for hemoglobin level) (-8.6% predicted; P < 0.001) during the first 6 months. Corresponding FEV1, FVC, TLC and DLCO declines in the subgroup with late measurements (after 11.3 months on average) were -5.7, -7.4, -7.0, -9.8% predicted. A multivariate analysis including V5 Gy, V10 Gy, V20 Gy, V40 Gy, V60 Gy, mean lung dose (MLD), gross tumor volume (GTV) and planning target volume (PTV) as potential covariates showed that GTV was the most consistent contributor, being significant for ∆FEV1 (P = 0.003), ∆FVC (P = 0.003), ∆TLC (P = 0.001) and ∆DLCO (P = 0.01). V5 Gy or V10 Gy did not contribute to any of the lung function changes. CONCLUSIONS: The decline in pulmonary function indices after helical tomotherapy was of similar magnitude to that observed in studies reporting the effect of conformal radiotherapy on lung function. Diffusion capacity was the parameter showing the largest decrease following radiation therapy as compared to baseline and correlated with gross tumor volume. None of the alterations in pulmonary function tests were associated with the lung volume receiving low-dose radiation.

Stereotactic radiotherapy for oligometastatic cancer: a prognostic model for survival.

BACKGROUND: Stereotactic radiotherapy (SRT) is a safe and locally effective treatment for patients with inoperable oligometastases. The challenge remains identifying subsets of patients that benefit in terms of overall survival (OS). PATIENTS AND METHODS: Between 2005 and 2011, 309 patients with ≤5 metastases were treated by stereotactic body radiotherapy (n=209) and/or by intracranial single or fractionated stereotactic radiotherapy (n=107). We analyzed OS and carried out a risk factor analysis. RESULTS: The median survival of all patients was 24 months. The 3-, 4- and 5-year OS rates were 32%, 25% and 19%, respectively. The following four risk factors were independently associated with impaired OS: nonadenocarcinoma histology (P<0.01), intracranial metastases (P<0.01), synchronous oligometastatic disease (P<0.01) and male gender (P=0.02). Patients with 0, 1 and 2 risk factors displayed a median survival (95% CI) of 40 (24-63), 29 (23-35) and 23 (16-29) months, respectively, and are defined as patients with good prognosis. Patients with 3 and 4 risk factors had a median survival of 9 (6-11) and 4 (1-7) months only and are defined as bad prognostic patients. CONCLUSIONS: We identified subsets of oligometastatic cancer patients with good prognosis after SRT. These patients are candidates for inclusion in prospective randomized trials for defining the role of SRT in the management of oligometastases.

Phase II study of stereotactic body radiotherapy to primary tumor and metastatic locations in oligometastatic nonsmall-cell lung cancer patients.

BACKGROUND: Stereotactic body radiotherapy (SBRT) has emerged as a treatment modality in patients presenting with oligometastatic nonsmall-cell lung cancer (NSCLC). SBRT is used as a local consolidative treatment to metastatic disease sites. The majority of patients included in SBRT trials for oligometastatic NSCLC have controlled primary tumors and brain metastases. PATIENTS AND METHODS: Oligometastatic NSCLC patients with ≤5 metastatic lesions were included in a prospective phase II trial to evaluate efficacy and toxicity of SBRT to all disease sites, primary tumor and metastatic locations. SBRT to a dose of 50 Gy in 10 fractions was delivered. Positron emission tomography-computed tomography (PET-CT) was carried out at baseline and 3 months after SBRT to evaluate the metabolic response rate according to PET Response Criteria in Solid Tumors (PERCIST). The progression-free survival (PFS) and overall survival (OS) were calculated using Kaplan-Meier method from start of chemotherapy or radiotherapy. Side-effects were scored using the National Cancer Institute Common Terminology Criteria for Adverse Events (NCI CTCAE) version 3.0. RESULTS: Twenty-six patients received SBRT after induction chemotherapy (n = 17) or as a primary treatment (n = 9). Median follow-up was 16.4 months. Overall metabolic response rate was 60% with seven patients (30%) achieving a complete metabolic remission and 7 (30%) a partial metabolic response. Any acute grade 2 toxicity was observed in four patients (15%) and grade 3 pulmonary toxicity in two patients (8%). Median PFS and OS were 11.2 and 23 months. The 1-year PFS and 1-year OS rate were 45% and 67%, respectively. CONCLUSION: SBRT to all disease sites, primary tumor and metastatic locations, in oligometastatic NSCLC patients produced an acceptable median PFS of 11.2 months.

Retrospective analysis of linac-based radiosurgery for arteriovenous malformations and testing of the Flickinger formula in predicting radiation injury.

BACKGROUND AND PURPOSE: The aim of the study was to validate the use of linac-based radiosurgery in arteriovenous malformation (AVM) patients and to predict complications using an integrated logistic formula (ILF) in comparison with clinical outcomes. PATIENTS AND METHODS: The results of radiosurgery in 92 AVM patients were examined. All patients were treated with linac-based radiosurgery. Of these, 70 patients were followed for 12-45 months (median, 24 months) and were analyzed. The treated volume varied from 0.09 to 26.95 cm(³) (median, 2.3 cm(³)) and the median marginal dose was 20 Gy (range, 10.4-22). The median 12-Gy volume was 9.94 cm(³) (range, 0.74-60.09 cm(³)). Patients and lesion characteristics potentially affecting nidus obliteration and excellent outcome were evaluated by performing a log-rank test and univariate and multivariate analyses. The risk for radiation injury (RRI) was calculated with an integrated logistic formula. The predictive power of the RRI was assessed by calculating the area under the receiver operating characteristic (ROC) curve. RESULTS: Follow-up magnetic resonance (MR) angiography revealed complete AVM obliteration in 56 of 70 patients. The MR angiography confirmed an obliteration rate of 80%. The annual hemorrhage rate was 1.4% for the first 2 years after radiosurgery and 0% thereafter. The number of patients with an excellent outcome was 48 (68%). Factors associated with better obliteration were higher radiation dose to the lesion margins [12-Gy volume (V12) >10 cm(³)], small volume, and a Pollock-Flickinger score less than 1.49; those predicting excellent outcomes were V12<10 cm(³), small volume, and Pollock-Flickinger score less than 1.49, as determined by multivariate analyses. Factors associated with radiation injury were V12>10 cm(³ )(p=0.03) and volume greater than 2 cm(³) (p=0.001), as determined by a univariate analysis. The analyses showed an ROC of 0.66. CONCLUSION: These data suggest that linac-based radiosurgery is effective. In terms of obliteration, excellent outcomes, and especially radiation injury, V12 and volume should be considered. The Flickinger formula seems to be applicable to Novalis-treated patients, but long-term follow-up is necessary for definite conclusions.

Phase II study of helical tomotherapy for oligometastatic colorectal cancer.

BACKGROUND: To evaluate the efficacy and toxicity of helical tomotherapy in the treatment of oligometastatic colorectal cancer (CRC) patients who were not amenable for metastasectomy and/or (further) systemic treatment. PATIENTS AND METHODS: CRC patients with five or less metastases were enrolled. No limitations concerning dimension or localization of the metastases were imposed. Patients were treated with intensity-modulated and image-guided radiotherapy using helical tomotherapy, delivering a total dose of 40 Gy in fractions of 4 Gy. Positron emission tomography-computed tomography (PET-CT) was carried out at baseline and 3 months after the initiation of radiotherapy to evaluate the metabolic response rate according to PET Response Criteria in Solid Tumors (PERCIST) version 1.0. Side-effects were scored using National Cancer Institute Common Terminology Criteria for Adverse Events (NCI-CTC AE) version 3.0. RESULTS: Twenty-three patients were enrolled. A total of 52 metastases were treated. One patient (4%) experienced grade 3 vomiting; two patients (9%) grade 2 diarrhea and dysphagia, respectively. Twenty-two patients were evaluated by post-treatment PET-CT. Five (23%) and seven patients (32%) achieved a complete and partial metabolic response, respectively, resulting in an overall metabolic response rate of 55%. The actuarial 1-year local control, progression-free survival, and overall survival were 54%, 25% and 86%, respectively. CONCLUSION: The use of helical tomotherapy in oligometastatic CRC patients resulted in a promising metabolic response rate of 55%.

An overview of volumetric imaging technologies and their quality assurance for IGRT.

Image-guided radiation therapy (IGRT) aims at frequent imaging in the treatment room during a course of radiotherapy, with decisions made on the basis of this information. The concept is not new, but recent developments and clinical implementations of IGRT drastically improved the quality of radiotherapy and broadened its possibilities as well as its indications. In general IGRT solutions can be classified in planar imaging, volumetric imaging using ionising radiation (kV- and MV- based CT) or non-radiographic techniques. This review will focus on volumetric imaging techniques applying ionising radiation with some comments on Quality Assurance (QA) specific for clinical implementation. By far the most important advantage of volumetric IGRT solutions is the ability to visualize soft tissue prior to treatment and defining the spatial relationship between target and organs at risk. A major challenge is imaging during treatment delivery. As some of these IGRT systems consist of peripheral equipment and others present fully integrated solutions, the QA requirements will differ considerably. It should be noted for instance that some systems correct for mechanical instabilities in the image reconstruction process whereas others aim at optimal mechanical stability, and the coincidence of imaging and treatment isocentre needs special attention. Some of the solutions that will be covered in detail are: (a) A dedicated CT-scanner inside the treatment room. (b) Peripheral systems mounted to the gantry of the treatment machine to acquire cone beam volumetric CT data (CBCT). Both kV-based solutions and MV-based solutions using EPIDs will be covered. (c) Integrated systems designed for both IGRT and treatment delivery. This overview will explain some of the technical features and clinical implementations of these technologies as well as providing an insight in the limitations and QA procedures required for each specific solution.

High dose irradiation after pleurectomy/decortication or biopsy for pleural mesothelioma treatment.

PURPOSE: The role played by radiation therapy after pleurectomy/decortication or surgical biopsy in malignant pleural mesothelioma is uncertain. We treated patients with accelerated hypofractionated radiotherapy using helical tomotherapy and intensity-modulated arc therapy in an attempt to keep lung toxicity to a minimum. The present study reports the feasibility and toxicity of this approach. MATERIAL AND METHODS: Between 2008 and 2012, 36 patients with malignant pleural mesothelioma underwent accelerated hypofractionated radiotherapy to the hemithorax after pleurectomy/decortication (19 patients) or biopsy (17 patients). The prescription dose was 25Gy in five fractions over 5 consecutive days. RESULTS: We observed three patients with G3 pneumonitis, five cases of grade 2 dyspnea and six cases of grade 2 cough. The median follow-up was 37 months (range: 3-54 months). The median overall survival for patients who underwent pleurectomy/decortication followed by radiotherapy was 21.6 months [95% confidence interval (95% CI): 15.5-24.1] compared to 19.4 months for patients not submitted to surgery. CONCLUSION: Treatment of intact lung with pleural intensity-modulated arc irradiation in malignant pleural mesothelioma patients with malignant pleural mesothelioma proved safe and feasible, with an acceptable rate of pneumonitis. Survival rates were encouraging for both biopsy-only and pleurectomy/decortication groups. We are currently conducting a phase II dose escalation trial in a similar patient setting to prospectively evaluate the impact of radiotherapy on toxicity, disease-free survival and overall survival.

Quantitative study of liver metastases from colon cancer in rats after treatment with cyclosporine A.

Liver metastases were produced in syngeneic BD IX rats by intraportal injection of colon cancer cell aggregates. The cells originated from the DHD/K12 cell line, derived from a 1,2-dimethylhydrazine (CAS: 540-73-8)-induced colon adenocarcinoma in BD IX rats. The animals received either cyclosporine A (CSA) or the excipients alone (control) through daily gastric intubation during 6 weeks. Multiple and very large hepatic metastases were observed early in 100% of the CSA-treated rats. The mean tumor volume was approximately 2,000 times higher in the CSA-treated group than in the controls (P less than .01). Survival time in the CSA-treated group was shortened (P less than .01) by generalized metastatic disease. Easy production of metastasis from colon cancer in 100% of the animals and precise estimation of tumor volume may prove useful for future therapeutic studies of secondary hepatic disease.

Optimal control of set-up margins and internal margins for intra- and extracranial radiotherapy using stereoscopic kilovoltage imaging.

In this paper the clinical introduction of stereoscopic kV-imaging in combination with a 6 degrees-of-freedom (6 DOF) robotics system and breathing synchronized irradiation will be discussed in view of optimally reducing interfractional as well as intrafractional geometric uncertainties in conformal radiation therapy. Extracranial cases represent approximately 70% of the patient population on the NOVALIS treatment machine (BrainLAB A.G., Germany) at the AZ-VUB, which is largely due to the efficiency of the real-time positioning features of the kV-imaging system. The prostate case will be used as an example of those target volumes showing considerable changes in position from day-to-day, yet with negligible motion during the actual course of the treatment. As such it will be used to illustrate the on-line target localization using kV-imaging and 6 DOF patient adjustment with and without implanted radio-opaque markers prior to treatment. Small lung lesion will be used to illustrate the system's potential to synchronize the irradiation with breathing in coping with intrafractional organ motion.

Effect of anticancer agents on directional migration of malignant C3H mouse fibroblastic cells in vitro.

Invasion of malignant cells was considered as a target for therapy. The effect of various anticancer agents, which were known to permit or to prevent invasion in vitro, on the growth and on the directional migration of virally transformed malignant C3H mouse fibroblastic cells (MO4) was examined. The increase of the diameter of spheroidal aggregates of MO4 cells in individual shaker culture was used as an index of growth. The mean diameter of the circular area covered by cells migrating from an aggregate explanted on glass, the number of cells in the periphery of this area, the height of the central part of the aggregate, the microcinephotographic aspect of migrating cells, and the immunocytochemistry of the cytoplasmic microtubular complex were considered as indices of directional migration. Ionizing radiation (5,000 and 20,000 R), and 5-fluorouracil (0.1, 0.5, and 1 microgram/ml), known to permit invasion, inhibited growth but allowed directional migration. Nocodazole (0.1 and 1 microgram/ml), known to prevent invasion, interfered with both growth and directional migration. These observations showed that various agents which affected the growth of aggregates of MO4 cells had different effects on the directional migration of these cells; they suggested that proliferation and migration were unrelated cellular activities. The assay for directional migration of cells from a spheroidal aggregate explanted on glass is proposed for the screening of potential antiinvasive agents.

Modification of cell surface carbohydrates and invasive behavior by an alkyl lysophospholipid.

The effect of the alkyl lysophospholipid racemic-1-O-octadecyl-2-O-methyl glycero-3-phosphocholine on the expression of cell surface carbohydrates of four matched pairs of normal and malignant cells was studied using chromatographic techniques. After treatment with alkyl lysophospholipid, glycopeptides proteolytically derived from normal and malignant cells displayed a shift in the size distribution profiles obtained by gel filtration. These drug-induced changes in molecular weight distribution were expressed most strongly in untransformed cells and resembled the carbohydrate alterations found after their malignant transformation. Desialylation abolished the effect of alkyl lysophospholipid, thus suggesting an increased amount of sialic acid in the surface carbohydrates of drug-treated cells. Chromatography of glycopeptides on concanavalin A-Sepharose, Ricinus communis agglutinin I-agarose, and Bio-Gel P-4 columns excluded a higher degree of branching but suggested addition of extra terminal sialic acid residues as the major cause of the observed alterations. Alkyl lysophospholipid stimulated glycoprotein sialylation of normal cells to the level observed in malignant cells, thus inducing a "malignant-like" surface phenotype. The drug-induced carbohydrate changes in normal chick heart tissue prevented its being invaded by tumor cells when tested in an organotypic assay. The alkyl lysophospholipid thus appears to modulate in a nontoxic fashion the expression of surface molecules implicated in various cellular interactions including invasiveness.

Activation of inducible nitric oxide synthase results in nitric oxide-mediated radiosensitization of hypoxic EMT-6 tumor cells.

EMT-6 cells treated for 16 h with 1-10 units/ml IFN-gamma showed a gradual activation of inducible nitric oxide synthase (iNOS) in Western and Northern blots, a simultaneous raise in NO output, and an increase in hypoxic cell radiosensitivity almost to the level of aerobic cells. Both the NO signal and radiosensitization were counteracted by the NO scavenger oxyhemoglobin, by the specific iNOS inhibitor aminoguanidine, and by the L-arginine analogue N(G)-monomethyl-L-arginine. Collectively, these data demonstrate that IFN-gamma can radiosensitize EMT-6 cells through iNOS induction and that NO is the effector molecule responsible for radiosensitization. Compared with the spontaneous NO releaser (2)-1-[N-(3-ammoniopropyl)-N-(n-propyl)amino)diazen-1-ium -1,2-diolate], the iNOS-generated NO signal appeared to be 10 times lower yet resulting in the same enhancement ratio of 2.4. Direct stimulation of NO synthesis in tumor cells through the L-arginine/iNOS pathway represents a novel approach to exploit the radiosensitizing properties of NO.

Antiinvasive activity of estramustine on malignant MO4 mouse cells and on DU-145 human prostate carcinoma cells in vitro.

Estramustine (EM) is a conjugate of estradiol and nor-nitrogen mustard (nor-HN2), which is effective in the treatment of prostate cancer. We have compared the effect of EM with that of the known microtubule inhibitor vinblastine (VLB) on the following functions of malignant MO4 mouse cells and of DU-145 human prostate cancer cells in vitro: directional migration, invasion; and the organization and the assembly/disassembly equilibrium of microtubule complexes. The circular area covered by cells migrating from an aggregate explanted on a solid substrate was taken as an index of directional migration. Invasion was studied through confrontation of MO4 or DU-145 cells with fragments of embryonic chick heart in organ culture. Microtubules were investigated immunocytochemically and through immunodetection on protein blots. VLB and EM inhibited directional migration and invasion of MO4 and DU-145 cells in a dose-dependent manner; equimolar combinations of estradiol plus nor-nitrogen mustard did not mimic these effects. At anti-invasive concentrations VLB led to partial disassembly of microtubule complexes, whereas EM resulted in an abnormal pattern of microtubule complexes without alteration of the overall assembly/disassembly equilibrium. Combined treatment with VLB and EM resulted in an enhanced VLB effect, namely complete disassembly. In all tests DU-145 cells were more sensitive to both VLB and EM than were MO4 cells, and the effects were less reversible. The present experiments showed that EM shares an anti-invasive activity with other microtubule inhibitors.

Antiinvasive effect of racemic 1-O-octadecyl-2-O-methylglycero-3-phosphocholine on MO4 mouse fibrosarcoma cells in vitro.

Alkyl-lysophospholipids have been shown to possess antitumoral activity in animal and in human tumors. Among them, racemic 1-O-octadecyl-2-O-methylglycero-3-phosphocholine (ET-18-OCH3) had an antimetastatic effect in experimental tumors. We investigated the effect of ET-18-OCH3 on invasion of MO4 mouse fibrosarcoma cells and on cellular activities possibly related to invasion in vitro. Ten micrograms of ET-18-OCH3 per ml permitted growth of MO4 cells to about 75% of controls and slightly reduced trypan blue exclusion. Directional migration inferred from the area covered by MO4 cells that had migrated from an aggregate on glass was not affected. Reassembly of microtubules after treatment with 1 microgram of Nocodazole per ml occurred normally in presence of ET-18-OCH3. Invasion was completely inhibited when MO4 cell aggregates were confronted with precultured fragments of embryonic chick cardiac muscle or with fresh embryonic chick lung fragments in culture on gyratory shaker in fluid medium with 10 micrograms of ET-18-OCH3 per ml. These experiments showed that ET-18-OCH3, in contrast with microtubule inhibitors, interfered with invasion of MO4 cells in vitro at concentrations that permitted growth and directional migration of MO4 cells. Fluorescence polarization studies with the lipophylic probe diphenylhexatriene indicated that the antiinvasive effect of ET-18-OCH3 was accompanied by an overall increase of membrane fluidity. We tentatively concluded that alterations of the MO4 cellular membranes are responsible for the antiinvasive effect of ET-18-OCH3.

Accelerated radiotherapy, carbogen, and nicotinamide in glioblastoma multiforme: report of European Organization for Research and Treatment of Cancer trial 22933.

PURPOSE: A three-step phase I/II trial associating accelerated radiotherapy with carbogen (step 1, ARCO), with nicotinamide (step 2, ARN), or with both (step 3, ARCON) was conducted, the aim of which was to overcome the effects of proliferation and hypoxia as potential causes of tumor radioresistance in glioblastoma multiforme. PATIENTS AND METHODS: Radiotherapy consisted of 60 Gy delivered over 4 weeks in 1.5-Gy fractions twice daily, 5 days a week. Carbogen breathing was started 5 minutes before each fraction and continued until the end of each treatment session. Nicotinamide was given daily as a single oral dose of 85 mg/kg. RESULTS: A total of 115 patients with a median age of 55 years were registered. Of 107 eligible patients, 23 were registered in step 1, 28 in step 2, and 56 in step 3. The planned treatment was administered without any interruption in 72% of patients (86% in ARCO but 68% in ARN and ARCON). The incidence and severity of acute skin and mucous membrane toxicity were higher in patients who received nicotinamide (ie, the ARN and ARCON groups). Grade 1 to 2 gastrointestinal toxicity was observed in 44% of patients in the ARN group and 32% of patients in the ARCON group, but only in 8% of patients in the ARCO group. Eight percent of evaluated patients presented with abnormal liver test results at treatment completion. The dose of corticosteroids had to be increased in 44% of patients. Late neurologic side effects were similar in all treatment steps and were observed mostly in patients with disease progression. Median survival times for patients treated with ARCO, ARN, and ARCON were 10.1, 9.7, and 11.1 months, respectively. CONCLUSION: Feasibility of ARCO treatment was good but that of ARN and ARCON was only fair. This probably reflected the higher acute toxicity rate, particularly gastrointestinal, for patients receiving nicotinamide. The dose of corticosteroids had to be increased frequently during treatment, suggesting a higher than expected acute neurologic toxicity. Overall survival was similar in the three treatment steps and not different when compared with results of other series that used radiotherapy alone.

Invasiveness and tumorigenicity of MO4 mouse fibrosarcoma cells pretreated with microtubule inhibitors.

MO4 cell aggregates with a diameter of 0.3 mm produced invasive fibrosarcomas after s.c. implantation into the pinna of syngeneic mice. Histology of pinnae fixed 10 min to 5 days after implantation of an aggregate suggested that the tumour was produced by the cells that invaded during the first day, and that the cells remaining in the aggregate were eliminated by the reaction of the host. Before implantation we have pretreated MO4 cell aggregates with 1 microgram/ml of the microtubule inhibitors Nocodazole (ND) and vincristine (VCR), known to inhibit both proliferation and invasion, and with 1 microgram/ml 5-fluorouracil (5-FU), known to inhibit proliferation but not invasion. Tumorigenicity was significantly reduced after treatment with ND or VCR, as compared to treatment with 5-FU or to controls. Histology of pinnae fixed 10 min to 3 days after implantation showed absence or scarceness of invasive MO4 cells after pretreatment with ND or VCR, in contrast with controls or with aggregates pretreated with 5-FU. The effect of ND, VCR and 5-FU on the growth of aggregates in culture on gyrotory shaker was reversible within 1 and 2 days respectively. After treatment with ND or VCR slight alterations in the function of the cytoplasmic microtubule complex remained visible during 3 days in cells migrating from an aggregate explanted on glass. Confrontation of pretreated aggregates with fragments of embryonic chick cardiac muscle in three-dimensional culture indicated that the anti-invasive effect of ND or VCR was reversible in vitro. We concluded that a delay of invasiveness caused by pretreatment with ND or VCR provided the host with the opportunity to eliminate MO4 cells implanted s.c. into the pinna.

Role of the host tissue in the anti-invasive activity of the alkyllysophospholipid, ET-18-OCH3, in vitro.

The alkyllysophospholipid, racemic-l-O-octadecyl-2-O-methylglycero-3- phosphocholine (ET-18-OCH3) was previously shown to inhibit invasion of malignant cells into precultured heart fragments (PHF) in vitro. In particular, pretreatment of PHF with 10 micrograms ET-18-OCH3 for 48 h was sufficient to induce in the host tissue resistance towards invasion by mouse MO4 cells. Resistance was obvious when MO4 cells were confronted either immediately (the pretreatment experiment) or after withdrawal of the drug 7 days prior to confrontation (the reversibility experiment). In the present study, the survival of PHF cells in the pretreatment and reversibility experiments was similar to that of untreated PHF cells as determined by the 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyltetrazolium bromide (MTT) test and by the PHF explantation test. The effective anti-invasive concentration was 6 micrograms/ml in the pretreatment experiment while 3 micrograms/ml was sufficient to inhibit invasion in the reversibility experiment. Induction of resistance towards invasion in pretreated PHF was shown to occur not only with MO4 cells but also with mouse LLC-H61 Lewis lung carcinoma and mouse BW-O-Li1 T-lymphoma cells. The increase in molecular weight of N-linked cell surface glycosylpeptides (N-GP) of PHF was apparent in the pretreatment experiment and was enhanced in the reversibility experiment. This effect was completely abolished in cells obtained from pretreated PHF which were converted into a cell suspension and further cultured as a monolayer on tissue culture plastic without drug for 7 days. The results reported here provide additional evidence for the causal involvement of N-GP of the PHF host tissue in the anti-invasive activity of ET-18-OCH3 in vitro.

An image analysis system for the quantification of invasion in vitro.

We have tested the value of a computer-assisted image analysis program for the quantitative study of invasion in vitro using experiments that were previously described semi-quantitatively. Mouse fibrosarcoma cell (MO4) aggregates were confronted with precultured fragments of embryonic chick heart in organ culture. Confronting pairs were fixed after 1, 2, 3 and 4 days, and processed for paraffin sectioning and immunostaining with an antiserum against chick heart. The image analysis system allowed separate quantification of two aspects of invasion, namely, occupation of the heart tissue by MO4 cells and degeneration of the invaded heart tissue. Complex combination of occupation and invasion added a qualitative aspect of invasion that has not been described previously and that revealed qualitative differences in invasion under various circumstances.

Is adjuvant treatment with vinblastine effective in reducing the occurrence of distant metastasis in limited squamous cell lung cancer? A randomized study.

In order to study the usefulness of treatment with vinblastine (VLB) in the prevention of cancer metastasis in squamous cell lung cancer, 50 patients with locoregional disease were randomized to receive either locoregional RT alone (group A) or a weekly intravenous bolus injection of VLB (6 mg/m2) concurrently with and after locoregional radiotherapy (RT) (55 Gy in 6 weeks) until the appearance of metastases (group B). Neither the incidence of death with metastases, metastasis-free survival (MFS) nor overall survival (S) were significantly affected by treatment with the drug. However, due to the limited number of patients in each group, the power of the statistical test was such to allow only the detection of differences in MFS and S to or more than 80 per cent at the P = 0.05 level. Local tumor response was significantly superior in group B (P less than 0.05). Acute toxicity (dysphagia, myelosuppression) during RT was significantly worse in group B. During long-term therapy with VLB, mild polyneuropathy developed in the majority of patients in group B. Furthermore, seven patients discontinued treatment with VLB during maintenance due to compliance (4) and excessive neurotoxicity (3). This treatment schedule with VLB is not recommended for patients with locoregional squamous cell lung cancer as significant toxicity is present during and after RT and significant increase in MFS and S is lacking. Because of an apparent increase in local response, the combination of VLB and RT merits further investigation in those tumors where local tumor control is crucial.