Extent Of Tumor Necrosis Research Articles

Transscleral thermotherapy with laser-induced and conductive heating in hamster Greene melanoma.

The purpose of this study was to investigate the cytotoxic effect of heat as induced by transscleral thermotherapy (TSTT), which may be of interest in the treatment of patients with choroidal melanoma. The aim of TSTT is to heat both the sclera and the tumor up to a cytotoxic temperature of about 60 degrees C. TSTT was performed in hamsters with subcutaneously implanted Greene melanoma covered by a specimen of human donor sclera of thickness 0.5, 0.7 or 0.9 mm. A newly developed applicator, which combines conductive episcleral heating at 60 degrees C with laser-induced heating, was used at laser powers ranging from 500 to 1500 mW delivered by an 810 nm diode laser, beam diameter 3 mm, and exposure time 1 min. Temperatures were measured at the scleral surface and at the sclera-tumor interface. The extent of tumor necrosis was examined by light microscopy and the sclera was examined by polarized light microscopy. Maximal depth of tumor necrosis without scleral damage was 4.4 (SD 1.5) mm. The temperature at the scleral surface after TSTT was 58.8 (SD 2.4) degrees C. The temperature at the sclera-tumor interface ranged from 56.4 (SD 3.7) degrees C at 500 mW to 65.3 (SD 4.4) degrees C at 1250 mW laser power. Structural changes to the scleral collagen started to develop at 1250 mW. TSTT with combined laser-induced and conductive heating caused cytotoxic temperatures in the tumor and the sclera, which were well tolerated by the scleral collagen.

Is tumor necrosis necessary to achieve a response in refractory tumors treated with intralesionally photoactivated talaporfin sodium (IPTS)?

8238 Background: Response to IPTS therapy, an investigational method proposed for treating refractory, bulky tumors, may differ from the typical necrosis pattern seen with radio-frequency ablation. To determine whether tumor necrosis is required to achieve a response to IPTS therapy, I performed the following analysis of the CT imaging findings from a Phase I safety study of IPTS. Methods: 21 patients with refractory, bulky tumors of varying histologic types were treated with IPTS by means of a light-emitting diode (LED) array placed percutaneously using CT guidance. The treatment zone was limited to a region within the tumor border. Contrast-enhanced CT studies were acquired on days 0, 7, 14, and 42. 19 of the 21 patients (90%) enrolled completed the study. Each tumor was assessed serially by measuring its longest dimension and by noting the extent of tumor necrosis as compared with the baseline measurement. Assessments were performed jointly by the principal investigator (PI) and a radiologist at each s...

Superiority of combined chemo-embolization and portal infusion with 5-fluorouracil over locoregional infusion concepts in Novikoff hepatoma-bearing rats

The aim of this study was to investigate experimentally whether there is a superior effect of the combination of hepatic artery chemo-embolization with portal vein infusion over either of the two treatment modalities alone. Novikoff hepatoma cells transplanted under the liver capsule of Sprague Dawley rats were used as a model. Tumor growth was assessed at 7 and 21 days after tumor inoculation. The prolamine solution Ethibloc was employed for embolization, and 5-fluorouracil was used as a chemotherapeutic agent for both infusion and chemo-embolization. All arterial treatment modalities were administered in a super-selective manner. There was no intolerable toxicity after dosages of 55 to 125 mg 5-fluorouracil/kg body weight. With regard to therapeutic efficacy the results show that embolization is an effective therapeutic means for inducing tumor necrosis in selected liver areas. As a consequence, the ranking of all treatment modalities was based on the combined evaluation of tumor size and extent of tumor necrosis. According to this evaluation, hepatic artery chemo-embolization was superior to the respective type of infusion (P<0.01). In addition, the combination of both modalities in the form of hepatic artery chemo-embolization and portal vein infusion was effective in destroying more than 97% of vital tumor tissue (P<0.01). These results suggest the need for a comparative clinical study.

Carbonic anhydrase IX expression, a novel surrogate marker of tumor hypoxia, is associated with a poor prognosis in non-small-cell lung cancer.

To evaluate carbonic anhydrase (CA) IX as a surrogate marker of hypoxia and investigate the prognostic significance of different patterns of expression in non-small-cell lung cancer (NSCLC). Standard immunohistochemical techniques were used to study CA IX expression in 175 resected NSCLC tumors. CA IX expression was determined by Western blotting in A549 cell lines grown under normoxic and hypoxic conditions. Measurements from microvessels to CA IX positivity were obtained. CA IX immunostaining was detected in 81.8% of patients. Membranous (m) (P =.005), cytoplasmic (c) (P =.018), and stromal (P <.001) CA IX expression correlated with the extent of tumor necrosis (TN). The mean distance from vascular endothelium to the start of tumor cell positivity was 90 micro m, which equates to an oxygen pressure of 5.77 mmHg. The distance to blood vessels from individual tumor cells or tumor cell clusters was greater if they expressed mCA IX than if they did not (P <.001). Hypoxic exposure of A549 cells for 16 hours enhanced CA IX expression in the nuclear and cytosolic extracts. Perinuclear (p) CA IX (P =.035) was associated with a poor prognosis. In multivariate analysis, pCA IX (P =.004), stage (P =.001), platelet count (P =.011), sex (P =.027), and TN (P =.035) were independent poor prognostic factors. These results add weight to the contention that mCA IX is a marker of tumor cell hypoxia. The absence of CA IX staining close to microvessels suggests that these vessels are functionally active. pCA IX expression is representative of an aggressive phenotype.

MR-imaging changes of musculoskeletal soft-tissue sarcomas associated with neoadjuvant chemotherapy and hyperthermia

Purpose: To evaluate early changes in musculoskeletal soft-tissue sarcomas under neoadjuvant chemotherapy combined with regional hyperthermia (RHT). Patients and methods: Nineteen consecutive patients with high-grade soft-tissue sarcomas of the musculoskeletal system were treated with neoadjuvant chemotherapy combined with RHT. Patients were imaged, using a high field MR-scanner, before onset of therapy, immediately after one and after four cycles of therapy. The images were evaluated for volume reduction and development of tumour necrosis. In addition, side effects such as surrounding soft-tissue oedema, bleeding and muscle or bone marrow necrosis were analysed. Results: Tumour volume reduction was significant after the completion of neoadjuvant therapy (mean 49%, range 5-91%; ( p < 0.001). Extent of tumour necrosis was also significantly different before (mean 22%) and after therapy (mean 58%, p < 0.001). Three patients showed strong tumour necrosis already after one cycle of treatment. Tumour volume reduction was not associated with the extent of pre-existing necrosis or necrosis development. The extent of tumour volume before start of therapy did not affect volume reduction or necrosis induction after therapy. Reduction of tumour oedema was significant after therapy ( p < 0.001). No side effects were observed during thermochemotherapy. Conclusion: Neoadjuvant chemotherapy combined with RHT resulted in significant tumour volume reduction and induction of tumour necrosis, which can be detected early and monitored closely with MRI.

Percutaneous radiofrequency thermal ablation of hepatocellular carcinoma: a safe and effective bridge to liver transplantation.

The incidence of hepatocellular carcinoma (HCC) is increasing in the United States. Although liver transplantation is an effective means of treating selected patients, pretransplantation tumor progression may preclude some patients from undergoing transplantation. The aim of this study is to determine the safety and efficacy of percutaneous radiofrequency thermal ablation (RFA) in 33 consecutive patients with nonresectable HCC and advanced cirrhosis. Mean subject age was 57.2 +/- 10.6 years, mean Child-Turcotte-Pugh score was 7.0 +/- 1.4, and mean maximal tumor diameter was 3.6 +/- 1.1 cm. Using contrast-enhanced computed tomography and magnetic resonance imaging, 22 patients (66%) had a complete radiological response at 3 months post-RFA, whereas 11 patients (33%) had an incomplete radiological response. During follow-up, 18 patients (54%) experienced tumor progression and 9 subjects underwent repeated ablation for either residual disease or tumor progression. The overall actuarial patient survival rate of the 33 patients was 58% at 2 years, whereas the transplantation-free patient survival rate was 34% at 2 years. Fifteen of 23 transplant candidates were successfully bridged to liver transplantation after a mean post-RFA follow-up of 7.9 +/- 6.7 months. The extent of tumor necrosis in the explant varied, but no subjects had evidence of tumor seeding on post-RFA imaging, at liver transplantation, or in the explant. The 3-year actuarial posttransplantation patient survival rate was 85%. Two patients have developed posttransplantation recurrence, and both had microscopic vascular invasion in their explants. In summary, our data show that RFA is a safe and effective treatment modality for patients with advanced cirrhosis and nonresectable HCC. Although the ability of RFA to prevent or delay tumor progression requires further prospective study, its favorable safety profile and promising efficacy make it an attractive treatment option for liver transplant candidates with nonresectable HCC.

Reduced blood flow and oxygenation in SA-1 tumours after electrochemotherapy with cisplatin.

Electrochemotherapy is an antitumour treatment that utilises locally delivered electric pulses to increase cytotoxicity of chemotherapeutic drugs. Besides increased drug delivery, application of electric pulses affects tumour blood flow. The aim of this study was to determine tumour blood flow modifying effects of electrochemotherapy with cisplatin, its effects on tumour oxygenation and to determine their relation to antitumour effectiveness. Electrochemotherapy of SA-1 subcutaneous tumours was performed by application of electric pulses to the tumours, following administration of cisplatin. Tumour blood flow modifying effects of electrochemotherapy were determined by measurement of tumour perfusion using the Patent blue staining technique, determination of tumour blood volume, and microvascular permeability using contrast enhanced magnetic resonance imaging, and tumour oxygenation using electron paramagnetic resonance oximetry. Antitumour effectiveness was determined by tumour growth delay and the extent of tumour necrosis and apoptosis. Tumour treatment by electrochemotherapy induced 9.4 days tumour growth delay. Tumour blood flow was reduced instantaneously and persisted for several days. This reduction in tumour blood flow was reflected in reduced tumour oxygenation. The maximal reduction in partial oxygen pressure (pO2) levels was observed at 2 h after the treatment, with steady recovery to the pretreatment level within 48 h. The reduced tumour blood flow and oxygenation correlated well with the extent of tumour necrosis and tumour cells apoptosis induced by electrochemotherapy with cisplatin. Therefore, the data indicate that antitumour effectiveness of electrochemotherapy is not only due to increased cytotoxicity of cisplatin due to electroporation of tumour cells, but also due to anti-vascular effect of electrochemotherapy, which resulted in reduced tumour blood flow and oxygenation.British Journal of Cancer (2002) 87, 1047–1054. doi:10.1038/sj.bjc.6600606 www.bjcancer.com© 2002 Cancer Research UK

Predictive value of histologic tumor necrosis after radiation

Postsurgical evaluation of histologic changes of tumors after preoperative chemotherapy and/or radiotherapy has been a routine clinical practice of pathologists and oncologists. There appears to be secure evidence that the extent of tumor necrosis vs. viable tumor cells postchemotherapy is a clinically useful predictor of outcome. The significance of histologic tumor necrosis after radiotherapy, however, has not been clearly established and deserves further investigation. We investigated the correlation between histological extent of tumor necrosis, survival of tumor transplants, and radiation doses in an experimental model using three human tumor xenografts. Three human tumor cell lines were investigated: STS-26, SCC-21, and HGL-21. Tumors were grown subcutaneously in athymic nude mice and received external beam radiation of different doses. Tumors were excised 2 weeks postirradiation. One-half of the tumor was divided into 1-mm(3) fragments and transplanted to naive mice. The other half was examined for histologic tumor necrosis. Transplant survival was strongly correlated with radiation dose, TCD(p) (radiation dose that results in local tumor control in proportion, p, to irradiated tumors). In contrast, there was no clear association between transplant survival rate and the extent of tumor necrosis. The experimental model demonstrated a strong inverse correlation between radiation doses and tumor transplant survival. Histologic tumor necrosis did not correlate well with radiation doses or transplant survival rates. Despite common practices in histologic examination of tumors posttherapy, clinical interpretations and implications of histologic tumor necrosis after radiotherapy should be considered with caution.

Correlation of MTS1/p16 and nm23 mRNA expression with survival in patients with peripheral synovial sarcoma

Background and Objectives Tumor supressor gene MTS1/p16 (cyclin-dependent kinase-4 inhibitor) and a putative tumor metastasis supressor gene nm23 (nucleoside diphosphate A kinase) have been identified in a variety of human tumors but have not been well studied in mesenchymal neoplasms. Methods Expression of nm23 and MTS1 mRNA was determined by quantitative analysis from paraffin-embedded tumor tissue. The series comprised 31 patients with localized primary synovial sarcoma of soft tissues who were followed for a median of 83 months. Results Neither MTS1 nor nm23 expression levels correlated with the patient's age or sex, tumor type, depth, size, mitotic rate, or extent of tumor necrosis. In addition, there was no correlation between MTS1 and nm23 levels. Patients' survival was not related to sex, age, tumor type, location, mitotic rate, or MTS1 mRNA level. The only factors that correlated with poor survival in multivariate analysis were the presence of extensive tumor necrosis (> 15%) and higher levels of nm23 mRNA. Conclusions Our results suggest that increased expression level of nm23 mRNA may be implicated in the mechanism of tumor progression and is associated with poor survival in patients with synovial sarcoma. J. Surg. Oncol. 2001;76:83–88. © 2001 Wiley-Liss, Inc.

Correlation of MTS1/p16 and nm23 mRNA expression with survival in patients with peripheral synovial sarcoma.

Tumor suppressor gene MTS1/p16 (cyclin-dependent kinase-4 inhibitor) and a putative tumor metastasis suppressor gene nm23 (nucleoside diphosphate A kinase) have been identified in a variety of human tumors but have not been well studied in mesenchymal neoplasms. Expression of nm23 and MTS1 mRNA was determined by quantitative analysis from paraffin-embedded tumor tissue. The series comprised 31 patients with localized primary synovial sarcoma of soft tissues who were followed for a median of 83 months. Neither MTS1 nor nm23 expression levels correlated with the patient's age or sex, tumor type, depth, size, mitotic rate, or extent of tumor necrosis. In addition, there was no correlation between MTS1 and nm23 levels. Patients' survival was not related to sex, age, tumor type, location, mitotic rate, or MTS1 mRNA level. The only factors that correlated with poor survival in multivariate analysis were the presence of extensive tumor necrosis (> 15%) and higher levels of nm23 mRNA. Our results suggest that increased expression level of nm23 mRNA may be implicated in the mechanism of tumor progression and is associated with poor survival in patients with synovial sarcoma.

Electrolytic Treatment of Colorectal Liver Tumour Deposits in a Rat Model: A Technique with Potential for Patients with Unresectable Liver Tumours

Background/Aims: Patients with unresectable malignant liver tumours have a poor prognosis. A technique is needed which improves long-term survival. Previous studies in the rat have shown that electrolysis is a safe, predictable and reproducible method for creating areas of necrosis in the normal rat liver. This study examined the effects of electrolysis on colorectal liver ‘metastases’ in the rat. Methods: Tumours of colorectal origin were implanted into the livers of Wistar-WAG rats. Two weeks after implantation the tumours were treated with electrolysis. A direct current generator, connected to 2 platinum intrahepatic electrodes was used to examine the effects of various electrode configurations on the extent of tumour necrosis. Results: Significant (p<0.001) tumour ablation was achieved with all electrode configurations. Tumour necrosis was more complete (p<0.05) with the electrodes positioned on either side of the tumour than with both electrodes placed in the centre of the tumour. Liver enzymes (AST and ALT) were significantly (p<0.001) elevated after treatment, but returned towards normal by 2 days. Conclusions: This study has shown that colorectal liver ‘metastasis’ can be ablated by electrolysis in a rat model. Two separate mechanisms of tumour ablation were observed: With the electrodes directly in or adjacent to the tumour, necrosis resulted from the action of cytotoxic electrode products, whereas by positioning the electrodes proximal to the tumour, necrosis was induced by a ‘secondary’ ischaemic effect. The findings confirm the view that electrolysis has great potential for treating patients with unresectable malignant liver tumours.

CHEMOEMBOLIZATION-INDUCED TUMOR NECROSIS: CORRELATION OF MRI, PATHOLOGY AND CLINICAL OUTCOME IN CIRRHOTICS WITH HEPATOCELLULAR CARCINOMA.

345 Purpose: We set out to determine how well MRI estimates of chemoembolization (CE) - induced tumor necrosis correlate with explant pathology and whether either is a predictor of outcome following OLT and chemo for the treatment of hepatocellular carcinoma (HCC). Methods: MRI is performed in all OLT candidates to estimate liver volume, to detect mass lesions, and to assess portal vein patency. Patients with known HCC undergo CE, OLT, and chemo. Biopsy for diagnosis of HCC was not performed routinely. Following each CE an MRI was done to determine percent necrosis of the targeted tumor(s), change in tumor size, and to check for additional lesions. Following OLT the explanted livers were examined and CE-induced tumor necrosis was quantified. Results: 360 OLT's were performed in 342 patients. CE was performed prior to OLT on 23 patients with known HCC. Three patients were excluded from analysis: two died of sepsis within 30 days of OLT and one patient had persistent disease after OLT. 16/20 patients are alive (median follow-up = 19 months). Six patients had recurrent HCC. MRI and pathologic data were complete for 13 patients with a total of 17 lesions. Pathologically nine tumors demonstrated >80% necrosis. Four tumors showed no necrosis and four demonstrated 20%, 30%, 70%, and 70% necrosis. In addition to necrosis it was noted that chemoembolized tumors were surrounded by a thick fibrous capsule. Estimates of tumor necrosis by MRI were within 10% of their pathologic assessment in 13/17 (76%) lesions. Percent necrosis by MRI and pathology in the 4 lesions that showed poor correlation were, respectively, 31% vs. 100%, 29% vs. 90%, 27% vs. 70%, and 87% vs. 70%. Cumulative adriamycin doses during CE of < 50 mg were used to treat 12 lesions whose mean necrosis was 14% whereas CE doses of >50 mg were used for 23 lesions whose mean necrosis was 74% (p<0.05). The number of CE treatments (1 vs. multiple) and the interval from CE to OLT (within 1 month vs. > 1 month prior to OLT) was not correlated with percent necrosis. There was no correlation between necrosis and clinical outcome. The six patients whose disease recurred had a mean tumor necrosis in 11 lesions of 44%. The fourteen patients who remain disease-free had a mean tumor necrosis in 24 lesions of 58%. Conclusions: The timing and frequency of CE did not have an impact on the degree of tumor necrosis but adriamycin doses > 50 mg administered during CE resulted in significantly more tumor necrosis than doses < 50 mg. MRI estimates of tumor necrosis compared very well with actual necrosis as determined by pathologic examination. There was no correlation between extent of tumor necrosis and recurrence rates. The presence of the fibrous capsule may be critical since the beneficial effect of CE in the treatment of HCC does not correlate with the degree of tumor necrosis induced by CE.

Cytolysis following chemoembolization for hepatocellular carcinoma.

Lipiodolized chemoembolization of hepatocellular carcinoma (HCC) can induce fever and cytolysis, defined as an increase in serum levels of liver transaminases, which is frequently assumed to result from tumour necrosis. This study aimed to assess the causes of this syndrome, reviewing preoperative data, intraoperative findings, tumour necrosis and the status of non-tumorous liver. A retrospective study was undertaken of 29 patients treated by neoadjuvant lipiodolized chemoembolization before surgical resection of HCC. Tumour necrosis was assessed in the resected specimen and scored in four stages: absent, 50 per cent or less, more than 50 per cent, and complete. The status of non-tumorous liver parenchyma was classified as either fibrotic or cirrhotic. Cytolysis occurred following chemoembolization in 16 patients and was associated with fever in 11. Postchemoembolization cytolysis with or without fever was more likely to develop in patients with minor fibrotic changes than in those with cirrhosis (14 of 21 with fibrosis versus two of four with cirrhosis, P < 0.05). In contrast, the extent of tumour necrosis did not correlate with the occurrence of symptoms. These results suggest that fever and cytolysis following chemoembolization of HCC are an indication not of tumour necrosis but of injury to the non-tumorous liver.

Photosensitizing effects of m-tetrahydroxyphenylchlorin on human tumor xenografts: correlation with sensitizer uptake, tumor doubling time and tumor histology.

The photodynamic effects of m-tetrahydroxyphenylchlorin (mTHPC) were assessed on human malignant mesothelioma, squamous cell carcinoma and adenocarcinoma xenografts grown in nude mice and were correlated with mTHPC uptake, histology and doubling time of the tumors. Non-thermal laser light was delivered to the tumor as surface radiation 4 days after intraperitoneal administration of 0.1 and 0.3 mg mTHPC/kg body weight, respectively. The extent of tumor necrosis was measured by histomorphometry. The mTHPC concentration in non-irradiated tumors was assessed by high-performance liquid chromatography (HPLC). The tumors were graded according to their doubling time and their vascular architecture as assessed by histology. The 0.1 mg/kg dose of mTHPC resulted in an equal uptake for all 3 tumor types but revealed a larger extent of photosensitized necrosis for adenocarcinoma, which displayed a delicate tumor stroma with numerous small capillary vessels, than for mesothelioma and squamous cell carcinoma, which were both poor in stroma and vessels. The 0.3 mg/kg dose of mTHPC resulted in a 2-fold higher tumor uptake for all 3 tumor types and in a larger extent of necrosis for mesothelioma and squamous cell carcinoma, but not for adenocarcinoma xenografts, compared with the lower drug dose. Our results demonstrate that different tumor xenografts respond differently to mTHPC-PDT for a given drug-light condition. In this setting, the photosensitizing effect was more closely related to the vascular architecture of the tumors than to the sensitizer uptake and doubling time of the different tumors

Role of ultrasonography for monitoring tumor necrosis after chemotherapy.

Ultrasonography for monitoring the response of malignant liver lesions to regional therapy offers several advantages. The instrument is easy to transport and can be used in intensive care units, so it is the procedure of choice within the first few days after invasive techniques, such as isolated liver perfusion, to demonstrate tumor response. Changes in size or in the sonomorphological pattern of liver lesions early after therapy indicate a therapeutic response. There are no data available on the sensitivity of ultrasonography for differentiating the necrotic and viable parts of the tumor. If information on the extent of tumor necrosis is crucial for decisions on further treatment of a patient, ultrasonography should be complemented with other techniques, such as fine-needle puncture or imaging techniques such as computed tomography, nuclear magnetic resonance, and single photon emission computed tomography. The contribution of more recent developments in ultrasonography, such as color Doppler analysis of intratumoral blood flow or three-dimensional ultrasonography, for monitoring tumor necrosis remains to be evaluated.

Hepatoblastoma: The Indiana Experience with Preoperative Chemotherapy for Inoperable Tumors; Clinicopathological Considerations

Analysis of the prognostic importance of various clinicopathological parameters in 17 hepatoblastomas (HBs) confirmed the utility of preoperative chemotherapy to convert inoperable to resectable tumors. There was no significant survival advantage for patients who underwent initial tumor resection compared with those resected following chemotherapy, although complete resection, with or without prior chemotherapy, was critical for cure. Young age was associated with better survival but did not correlate with histologic subtype or clinical stage. A relationship between low initial alpha-fetoprotein (AFP) level and tumor resectability was noted, perhaps related to tumor size, but tumor location was of greater importance than size in determining resectability. Neither the mean proportions of fetal and embryonal epithelium, nor their mitotic activity, nor the presence of vascular invasion in the prechemotherapy biopsy specimens was predictive of outcome, but the low mitotic activity of the fetal component correlated with ultimate resectability. On the other hand, although complete resection was necessary for survival, histologic examination of postchemotherapy specimens had additional predictive value; the presence of vascular invasion, the amount of viable mesenchyme, the extent of tumor necrosis, the proportion of embryonal epithelium, and the mitotic activity of the epithelial component in postchemotherapy resection specimens were each predictive of outcome. Although the presence of osteoid was not predictive, both the proportion of HBs that contained osteoid and the extent of mature mesenchymal tissues within individual HBs were increased by chemotherapy, suggesting that maturation of previously immature clones had been induced. We conclude that although complete resectability remains the fundamental goal of therapy, evaluation of the clinicopathologic characteristics that we have found to be predictive of outcome may permit tailoring of therapeutic regimens to individual patients; those whose tumors are deemed likely to respond well may require less toxic preoperative chemotherapy, and those deemed likely to progress in spite of complete resection may be considered for more aggressive postoperative regimens.

Enhanced apoptosis predicts shortened survival in non-small cell lung carcinoma

This study was undertaken to determine the extent of apoptosis in lung carcinoma and to evaluate it as a prognostic marker. A series of 75 lung carcinomas (47 squamous cell carcinomas, 24 adenocarcinomas, 3 small cell carcinomas, and 1 large cell carcinoma) was analyzed for the extent of apoptosis by using the 3' end-labeling method of DNA in tissue sections. Apoptosis was correlated with the rate of cell proliferation, the immunohistochemically detectable p53 and bcl-2, the extent of tumor necrosis, and the survival data. The end-labeling method allowed a precise evaluation of the extent of apoptosis. In tumor tissue, the number of apoptotic bodies was roughly 2-fold greater than the number of apoptotic cells, whereas in nonneoplastic control tissues, the ratio was 1:1. The apoptotic indexes (percentages of apoptotic cells and bodies among tumor cells) were slightly higher in adenocarcinoma than in squamous cell carcinoma. There was no association between the extent of apoptosis and the expression of proliferating cell nuclear antigen or p53. On the other hand, tumor necrosis correlated significantly with proliferating cell nuclear antigen and p53 positivity (P = 0.00025 and 0.00087, respectively). Surprisingly, the extent of apoptosis was also found to be independent of the expression of bcl-2. Patients with apoptotic indexes greater than 1.5% had significantly shorter survival time than patients with apoptotic indexes equal to 1.50% or less (P < 0.01 by log rank). Aberrant p53 positivity also predicted a poor prognosis (P < 0.002 by log rank). By multivariate analysis, enhanced apoptosis showed a 1.9-fold risk (P = 0.04), and p53 positivity showed a 2.3-fold risk (P = 0.005) for a shortened survival. We conclude that both enhanced apoptosis and p53 positivity are independent prognostic markers in non-small cell lung carcinoma, predicting shortened survival time of the patients.

Expression of P-glycoprotein in high-grade osteosarcomas in relation to clinical outcome.

Increased levels of P-glycoprotein occur in some osteosarcomas. In this study we determined the relation between P-glycoprotein status and outcome in patients with high-grade osteosarcoma. P-glycoprotein status was determined immunohistochemically in specimens of osteosarcoma of the extremities (stage II) from 92 patients who were treated with surgery and chemotherapy. The P-glycoprotein status was analyzed in relation to the length of event-free survival. The presence of increased levels of P-glycoprotein in the osteosarcoma was significantly associated with a decreased probability of remaining event-free after diagnosis (P = 0.002). In a multivariate analysis, P-glycoprotein status (P = 0.001) and the extent of tumor necrosis after preoperative chemotherapy (P = 0.04) were independent predictors of clinical outcome. The risk of adverse events was increased substantially (rate ratio, 3.37; 95 percent confidence interval, 1.60 to 7.10) among patients with increased levels of P-glycoprotein in tumor cells, as compared with patients who did not have increased levels of P-glycoprotein in tumor cells. In patients with high-grade osteosarcoma treated with surgery and chemotherapy, the presence of increased levels of P-glycoprotein in tumor cells is associated with a significantly increased risk of adverse events and is independent of the extent of necrosis after preoperative chemotherapy.

Aluminium phthalocyanine mediated photodynamic therapy in experimental malignant glioma

The efficacy of aluminium tetrasulfonated phthalocyanine (AISPc) as a photosensitizer for photodynamic therapy (PDT) was investigated in the C6 glioma model in Wistar rats. The depth and extent of tumour necrosis was dependent on both the dosage of intravenously (IV) administered AISPc, and the dose and time post-sensitization of 675 nm light administration. There was no effect on tumour or normal brain if the sensitizer dose was less than 0.5 mg/kg. Selective necrosis of tumour was evident 6 hours post-sensitization at an AISPc dose up to 1 mg/kg and light doses up to 200 J/cm 2. Necrosis occurred in normal brain at higher doses of light and sensitizer. There was no photosensitizer effect in animals treated 24 hours post AISPc administration. The ability of AISPc to act as a selective photosensitizer causing photonecrosis provides a basis for the generation of modified AISPc species as future agents in the PDT of brain tumours, especially as these sensitizers absorb light at a higher wavelength than those that are currently available.

LEVELS OF P53 ANTIGEN IN THE SERUM OF NONSMALL CELL LUNG-CANCER PATIENTS CORRELATE WITH POSITIVE P53 IMMUNOHISTOCHEMISTRY ON TUMOR SECTIONS, TUMOR NECROSIS AND NODAL INVOLVEMENT

We examined 50 non-small cell lung cancers and the matching serum from the same patients for the levels of p53 antigen. Histological sections of the tumor specimens were stained with anti-p53 specific antibodies, and the sera were tested by ELISA. We observed a correlation between the expression of the p53 protein in the tumors and the presence of circulating p53 antigen, using either a wild type-(P=0.024) or a mutant specific (P=0.007) ELISA test. The p53 serum levels were also significantly associated (P=0.019) with the extent of tumor necrosis, suggesting that circulating p53 may be derived by shedding from dead tumor cells. The levels of mutant p53 detected in the serum were significantly higher in patients with lymph node involvement (P=0.012) and with late-staged disease. (P=0.05). No association was found with tumor size and extent. Testing for serum levels of mutant p53 could provide additional prognostic information and could be used as as novel molecular diagnostic tool in the management of non-small cell lung cancer.