99mTc-sestamibi imaging in the assessment of toremifene as a modulator of multidrug resistance in patients with breast cancer

Multidrug resistance (MDR) due to expression of a membrane-associated permeability glycoprotein (P-glycoprotein [Pgp]) prevents successful cytotoxic chemotherapy for breast cancer. Identification of MDR would facilitate selection of chemotherapy regimens and MDR modulators. This study aimed to evaluate (99m)Tc-sestamibi imaging for predicting overexpression of Pgp in primary breast cancer and to measure the efficacy of toremifene, the MDR modulator, in vivo.

METHODS

Twenty patients with untreated breast cancer had (99m)Tc-sestamibi imaging 20 and 120 min after tracer injection before and after a 3-d course of toremifene (780 mg/d). Tumor samples were obtained during surgery for correlation of imaging and Pgp immunohistochemistry.

RESULTS

Sixteen of 20 tumors were visualized with sestamibi. Before toremifene, there was a significant inverse correlation (Spearman rank correlation coefficient [R(S)]) between staining intensity, based on the anti-Pgp monoclonal antibodies C494 and C219, and the tumor-to-background ratio (T/B) at 120 min (R(S) = -0.85; P < 0.001 and R(S) = -0.71; P < 0.001, respectively). However, the correlation between the T/B and immunohistochemistry at 20 min was significant only for C494 (R(S) = -0.57; P < 0.01). Similarly, before toremifene, there was an inverse correlation between staining intensity and the change in the T/B between 20 and 120 min (R(S) = -0.77; P < 0.001 and -0.75; P < 0.001 for C494 and C219). After toremifene, an inverse correlation between staining intensity and the T/B was seen only at 120 min and only with C494 (R(S) = -0.68; P < 0.01). However, the change in the T/B between 20 and 120 min correlated significantly with staining intensity for C494 and C219 (R(S) = -0.68; P < 0.01 and -0.7; P < 0.01 for C494 and C219, respectively). Toremifene did not significantly alter the overall T/B at either 20 or 120 min when data were compared before and after toremifene. Nevertheless, at 120 min, 8 of 8 tumors with low Pgp expression showed reduced uptake after toremifene, whereas 5 of 6 tumors with strong expression showed increased uptake (P < 0.003). Moreover, there was a significant correlation between the change in the T/B and staining intensity with C494 (R(S) = 0.59; P < 0.05) and C219 (R(S) = 0.56; P < 0.05) at 120 min but not at 20 min.

CONCLUSION

(99m)Tc-Sestamibi accumulation in breast cancer correlates with Pgp expression. Toremifene has a dual effect on this accumulation, increasing it through an inhibitory effect on Pgp while at the same time reducing it by a direct competition with sestamibi. The latter implies that in response to Pgp modulation the efflux of various agents may be affected differently.

Cytotoxic therapy of gastroenteropancreatic (GEP) tumors

Neuroendocrine gut and pancreatic tumors have provided a diagnostic and therapeutic challenge over the years. Although they are considered slow growing, when disseminated their prognosis is poor. Currently, the various therapeutic options available for patients with inoperable GEP tumors aim either to control symptoms engendered by bioactive mediators, released by tumor cells, or to achieve control of tumor proliferation. The interpretation of the efficacy of the cytotoxic therapy on GEP tumors is hampered by the small size of the studies performed and the inconsistence in tumor type, origin and degree of differentiation. Nevertheless, it is widely recognized that chemotherapy has some role in the management of Neuroendocrine Pancreatic Tumors (NPTs); while in Metastatic Carcinoid Tumors (MCTs) it has only a minimal effect.

Phase II study of pegylated liposomal doxorubicin (Caelyx) as induction chemotherapy for patients with squamous cell cancer of the head and neck

A phase II trial of pegylated liposomal doxorubicin (Caelyx) as induction chemotherapy was conducted in 20 patients with treatment-naïve squamous cell cancer of the head and neck (SCCHN). 10 patients received two cycles of Caelyx (40 mg/m(2)) every 3 weeks before starting radical radiotherapy (RT). Subsequently, consecutive groups of 3 patients received a third escalating dose of Caelyx (10, 15 and 20 mg/m(2)) 3 days before RT. 9 of 18 (50%, 95% confidence intervals (CI): 26-74%) evaluable patients responded to Caelyx, with 11 responses in 26 (42%, 95% CI: 24-62%) evaluable sites (three complete responses (12%), eight partial responses (31%)). There was no grade 3/4 haematological, mucosal or cardiac toxicity. Nausea and vomiting were minimal. There were no drug-related RT delays. Local RT-induced toxicity was not increased. Caelyx has significant activity against SCCHN and warrants further investigation in this disease. In view of its tumour targeting properties and activity at moderate doses, it may be useful in concomitant chemoradiotherapy strategies for SCCHN.

Gene therapy for prostate cancer: current status and future prospects

PURPOSE

Locally advanced, relapsed and metastatic prostate cancer has a dismal prognosis with conventional therapies offering no more than palliation. In recent years advances achieved in understanding the molecular biology of cancer have afforded clinicians and scientists the opportunity to develop a range of novel genetic therapies for this disease.

MATERIALS AND METHODS

We performed a detailed review of published reports of gene therapy for prostate cancer. Particular emphasis was placed on recent developments in the arena of nonviral (plasmid DNA, DNA coated gold particles, liposomes and polymer DNA complexes) and viral (adenovirus, retrovirus, adeno-associated virus, herpes virus and pox virus) vectors. Therapeutic strategies were categorized as corrective, cytoreductive and immunomodulatory gene therapy for the purpose of data analysis and comparison.

RESULTS

Locoregional administration of nonviral and viral vectors can yield impressive local gene expression and therapeutic effects but to our knowledge no efficient systemically delivered vector is available to date. Corrective gene therapy to restore normal patterns of tumor suppressor gene (p53, Rb, p21 and p16) expression or negate the effect of mutated tumor promoting oncogenes (ras, myc, erbB2 and bcl-2) have efficacy in animal models but this approach suffers from the fact that each cancer cell must be targeted. A wide variety of cytoreductive strategies are under development, including suicide, anti-angiogenic, radioisotopic and pro-apoptotic gene therapies. Each approach has strengths and weaknesses, and may best be suited for use in combination. Immunomodulatory gene therapy seeks to generate an effective local immune response that translates to systemic antitumor activity. Currently most studies involve immunostimulatory cytokine genes, such as granulocyte-macrophage colony-stimulating factor, or interleukin-2 or 12.

CONCLUSIONS

Various therapeutic genes have proved activity against prostate cancer in vitro and in vivo. However, the chief challenge facing clinical gene therapy strategies is the lack of efficient gene delivery by local and systemic routes. For the foreseeable future vector development may remain a major focus of ongoing research. Despite this caveat it is anticipated that gene therapy approaches may significantly contribute to the management of prostate cancer in the future.

The effect of irradiation on the biodistribution of radiolabeled pegylated liposomes

PURPOSE

The effect of total-body irradiation (TBI) on the biodistribution and pharmacokinetics of (111)In-DTPA-labeled pegylated liposomes (IDLPL) was evaluated in tumor-bearing nude mice as part of an ongoing effort to develop liposome-targeted radiosensitizers.

METHODS AND MATERIALS

Mice received TBI (2 Gy or 5 Gy) according to two protocols: (1) to test the effect of radiation delivered 30 min before liposome injection on the time course of IDLPL biodistribution to tumor and normal tissues over 96 h; (2) to test the effect of radiation at times ranging from 72 h to 1 h before liposome injection on tumor and normal tissue uptake of IDLPL at 24 h. Tumor and tissue/organ levels of liposome uptake were measured by dissection and quantitation in a gamma counter.

RESULTS

For most tissues (tumor, liver, kidney, lung, skin, heart, and central nervous system), irradiation did not alter IDLPL biodistribution. Splenic uptake appeared to be increased by TBI, but further analysis revealed that this effect was due to reduced splenic weight in irradiated mice. IDLPL uptake was increased in the small intestine, stomach, musculoskeletal system, female reproductive tract, and adrenal glands in irradiated mice.

CONCLUSION

These findings suggest that concomitant administration of liposomal radiosensitizers during radical radiotherapy is likely to be safe. However, caution should be exercised in situations in which significant volumes of small intestine or hemopoietic tissue will be irradiated.

The development of monoclonal antibody therapy in leukemias

Conventional cytotoxic management of leukemia has less than optimal results, while it is associated with life-threatening toxic effects due to lack of specificity for hematopoietic cells. Therefore, novel therapeutic strategies with monoclonal antibodies (MAbs) are being explored for delivering chemotherapy or radiation directly to malignant cells. Recently, anti-CD33 antibodies have been engineered to target malignant myeloid and immature normal cells and have been used to deliver cytotoxic agents or radiation to leukemic cells. 131I-labeled anti-CD45 antibodies are used in combination with conventional chemotherapy in leukemic patients receiving marrow transplantation. Additionally, the emergence of Rituximab (against CD20) and Campath-1H (against CD52) for chronic lymphocytic leukemia (CLL) has provided encouraging clinical results for the prognosis of this disease. In conclusion, there has been ongoing research indicating that the approach of patients with leukemia through the application of MAbs might be safer and more effective than current treatment. Considering the preliminary data, MAb therapy appears to be a new, promising weapon in the oncologist's armentarium.

Balanced branching in transcription termination

The theory of stochastic transcription termination based on free-energy competition [von Hippel, P. H. & Yager, T. D. (1992) Science 255, 809-812 and von Hippel, P. H. & Yager, T. D. (1991) Proc. Natl. Acad. Sci. USA 88, 2307-2311] requires two or more reaction rates to be delicately balanced over a wide range of physical conditions. A large body of work on glasses and large molecules suggests that this balancing should be impossible in such a large system in the absence of a new organizing principle of matter. We review the experimental literature of termination and find no evidence for such a principle, but do find many troubling inconsistencies, most notably, anomalous memory effects. These effects suggest that termination has a deterministic component and may conceivably not be stochastic at all. We find that a key experiment by Wilson and von Hippel [Wilson, K. S. & von Hippel, P. H. (1994) J. Mol. Biol. 244, 36-51] thought to demonstrate stochastic termination was an incorrectly analyzed regulatory effect of Mg(2+) binding.

Phase I-II study of pegylated liposomal cisplatin (SPI-077) in patients with inoperable head and neck cancer

BACKGROUND

Concomitant chemoradiotherapy (CCRT) for squamous cancers of the head and neck (SCCHN) improves survival but increases toxicity. Pegylated liposomes localise to solid cancers and may deliver radiosensitizing agents preferentially to tumour tissue, potentially improving the therapeutic ratio of CCRT.

PATIENTS AND METHODS

A phase I-II trial of pegylated liposome encapsulated cisplatin (SPI-077) was conducted in 18 patients with treatment-naive locally advanced, inoperable SCCHN. The first 10 patients received 2 cycles of 200 mg/m2, and the next 8 received 260 mg/m2, every 3 weeks before commencing radical radiotherapy (RT).

RESULTS

Only 2 of 18 (11%) patients had partial responses to SPI-077 with 2 responses in 29 (6.9%) evaluable sites. SPI-077 was tolerated well with no haematological, renal, hepatic or neurological toxicities. Nausea and vomiting were minimal. There were no drug-related delays in the delivery of RT. RT-induced mucosal and cutaneous toxicity were not significantly increased.

CONCLUSIONS

SPI-077 is essentially inactive against SCCHN and, in its present formulation, does not merit further evaluation as induction chemotherapy or as part of a CCRT approach.

Single-fraction irradiation has no effect on uptake of radiolabeled pegylated liposomes in a tumor xenograft model

PURPOSE

These studies were performed with the intention of examining the effect of single-fraction doses of radiotherapy (RT) on the tumor deposition of radiolabeled pegylated liposomes in an animal xenograft tumor model.

METHODS AND MATERIALS

Human KB head-and-neck xenograft tumors were established in female nude mice. The effect of single fraction tumor RT doses (5, 10, 15, and 20 Gy) on the tumor uptake of intravenously administered (111)In-DTPA-labeled pegylated liposomes (IDLPL) was examined using two protocols: (1) to test the effect of RT delivered 30 min before liposome injection on the time course of tumor uptake over a 96-h period; (2) to test the effect of RT at times ranging from 72-h to 1-h before liposome injection on the levels of liposome uptake at 24 h. Tumor and normal tissue/organ (blood, liver, spleen, lung, and kidney) liposome uptake was determined by dissection and quantitation in a gamma counter.

RESULTS

There was no demonstrable effect of RT on tumor uptake of IDLPL (p > 0.1 for all comparisons). Reassuringly, neither was there an effect of RT on the pharmacokinetics and biodistribution of radiolabeled liposomes to normal tissues.

CONCLUSIONS

Single fraction doses of RT appear to have no effect on tumor or normal tissue biodistribution and pharmacokinetics of radiolabeled pegylated liposomes in this animal model.

Effective targeting of solid tumors in patients with locally advanced cancers by radiolabeled pegylated liposomes

The biodistribution and pharmacokinetics of (111)In-DTPA-labeled pegylated liposomes (IDLPL) were studied in 17 patients with locally advanced cancers. The patients received 65-107 MBq of IDLPL, and nuclear medicine whole body gamma camera imaging was used to study liposome biodistribution. The t(1/2beta) of IDLPL was 76.1 h. Positive tumor images were obtained in 15 of 17 studies (4 of 5 breast, 5 of 5 head and neck, 3 of 4 bronchus, 2 of 2 glioma, and 1 of 1 cervix cancer). The levels of tumor liposome uptake estimated from regions of interest on gamma camera images were approximately 0.5-3.5% of the injected dose at 72 h. The greatest levels of uptake were seen in the patients with head and neck cancers [33.0 +/- 15.8% ID/kg (percentage of injected dose/kg)]. The uptake in the lung tumors was at an intermediate level (18.3 +/- 5.7% ID/kg), and the breast cancers showed relatively low levels of uptake (5.3 +/- 2.6% ID/kg). These liposome uptake values mirrored the estimated tumor volumes of the various tumor types (36.2 +/- 18.0 cm3 for squamous cell cancer of the head and neck, 114.5 +/- 42.0 cm3 for lung tumors, and 234.7 +/- 101.4 cm3 for breast tumors). In addition, significant localization of the liposomes was seen in the tissues of the reticuloendothelial system (liver, spleen, and bone marrow). One patient with extensive mucocutaneous AIDS-related Kaposi sarcoma was also studied according to a modified protocol, and prominent deposition of the radiolabeled liposomes was demonstrated in these lesions. An additional two patients with resectable head and neck cancer received 26 MBq of IDLPL 48 h before undergoing surgical excision of their tumors. Samples of the tumor, adjacent normal mucosa, muscle, fat, skin, and salivary tissue were obtained at operation. The levels of tumor uptake were 8.8 and 15.9% ID/kg, respectively, with tumor uptake exceeding that in normal mucosa by a mean ratio of 2.3:1, in skin by 3.6:1, in salivary gland by 5.6:1, in muscle by 8.3:1, and in fat by 10.8:1. These data strongly support the development of pegylated liposomal agents for the treatment of solid tumors, particularly those of the head and neck.

Pegylated liposome-encapsulated doxorubicin and cisplatin enhance the effect of radiotherapy in a tumor xenograft model

Concomitant chemotherapy and radiotherapy (CCRT) has recently been shown to improve treatment outcome in a range of solid tumors. Pegylated liposomes have the potential to target drugs directly to tumors and may increase the efficacy and reduce the toxicity of CCRT by selectively delivering radiosensitizing agents to tumor, as opposed to normal, tissues. In these studies, we have assessed CCRT using pegylated liposome encapsulated doxorubicin (PLED) and pegylated liposome encapsulated cisplatin (PLEC) against KB head and neck cancer xenograft tumors in nude mice. The addition of low-dose (2 mg/kg) PLED (P < 0.001) and PLEC (P < 0.001) significantly increased the effect of 4.5 Gy, but not 9 Gy, single-fraction radiotherapy (SFRT). Both PLED and PLEC were significantly more effective than their unencapsulated counterparts in increasing the effect of SFRT. In addition, PLED (P < 0.001) and PLEC (P < 0.05) significantly increased the effect of fractionated radiotherapy (9 Gy in 3 fractions) in two different dosing schedules (2 mg/kg single dose or three sequential doses of 0.67 mg/kg). Unencapsulated diethylenetriaminepentaacetic acid and pegylated liposomal diethylenetriaminepentaacetic acid were used as controls to test the effect of the liposome vehicle and showed no interaction with 4.5 Gy or 9 Gy SFRT (P > 0.1). CCRT was well-tolerated, with no evidence of increased local or systemic toxicity, as compared with radiotherapy alone. This study is the first to demonstrate the value of pegylated liposomes as vehicles for the delivery of radiosensitizing drugs in CCRT strategies.

Cancer gene therapy: developments to 2000

Cancer, at the molecular level, continues to be more thoroughly understood. With this understanding comes the opportunity for innovative therapeutic intervention. Gene therapy remains an attractive concept to treat cancer. However, a number of gene therapy clinical trials have now been reported and it is clear that barriers remain before gene therapy gains widespread clinical application. This article outlines current directions and novel developments in the field of cancer gene therapy, which attempt to overcome these obstacles.

The role of E-cadherin-catenin complex: more than an intercellular glue?

It is now widely recognized that alterations in the adhesion properties of neoplastic cells may play a pivotal role in the development and progression of the malignant phenotype in a range of tumor types. The cadherins and catenins, being the prime mediators of cell-cell adhesion, are intimately involved in the control of morphological differentiation and cellular proliferation; loss of their intercellular function allows malignant cells to escape from their site of origin, degrade the extracellular matrix, acquire a more motile and invasive phenotype, and, finally, invade and metastasize. In addition to participating in tumor invasiveness and metastasis, the E-cadherin-catenin complex is fundamental for the establishment and maintenance of multicellular organisms and regulates or significantly contributes to a variety of functions, including signal transduction, cell growth, differentiation, site-specific gene expression, morphogenesis, immunologic function, cell motility, wound healing, and inflammation. We reviewed the role of the E-cadherin-catenin complex in tumor development and presented the potential clinical applications of these molecules.

Transcriptional control: an essential component of cancer gene therapy strategies?

The therapeutic index of cancer gene therapy approaches will, at least in part, be dictated by the spatial and temporal control of expression of the therapeutic transgenes. Strategies which allow precise control of gene transcription are likely to play a crucial role in the future pre-clinical and clinical development of gene therapy. In this review, we discuss these issues as they relate to tissue and tumor specific promoters. In addition, the exciting opportunities offered by the development of regulated gene expression systems using small molecules, radiation and heat are reviewed. It is realistic to expect that the future offers the prospect of amalgamating elements of a number of these different systems in a co-ordinated gene delivery approach with the potential to increase the efficacy and reduce the toxicity of treatment.

Influence of tumour size on uptake of(111)ln-DTPA-labelled pegylated liposomes in a human tumour xenograft model

The relationship between tumour size and uptake of(111)In-DTPA-labelled pegylated liposomes has been examined in a human head and neck cancer xenograft model in nude mice. The mean tumour uptake of(111)In-labelled pegylated liposomes at 24 hours was 7.2 +/- 6.6% ID/g. Liposome uptake for tumours < 0.1 g, 0.1-1.0 g and > 1.0 g was 15.1 +/- 10.8, 5.9 +/- 2.2 and 3.0 +/- 1.3% ID/g, respectively. An inverse correlation between tumour weight and liposome uptake was observed by both Spearman's rank correlation test (r(s)= - 0.573, P< 0.001) and Pearson's correlation coefficient (r(s)= - 0.555, P< 0.001). For 18 tumours with macroscopic central necrosis, the ratio of uptake in the tumour rim relative to the necrotic tumour core was 11.2 +/- 6.4. Measurement of tumour vascular volume for tumours of various sizes revealed an inverse correlation between tumour weight and tumour vascular volume (Spearman's rank correlation test, r(s)= - 0.598, P< 0.001), consistent with poor or heterogeneous vascularization of larger tumours. These data have important implications for the clinical application of pegylated liposome targeted strategies for solid cancers which are discussed in detail.

Pegylated liposome-encapsulated doxorubicin and cisplatin in the treatment of head and neck xenograft tumours

PURPOSE

To evaluate the in vitro and in vivo activity of unencapsulated doxorubicin (DOX) and cisplatin (CDDP) and their pegylated liposome encapsulated counterparts (PLED and PLEC) in a subcutaneous model of human squamous cell cancer of the head and neck.

METHODS

In vitro cytotoxicity was determined by means of the sulphorhodamine B assay and in vivo activity was assessed in terms of tumour growth delay following single intravenous doses of the various agents. Treatment-related toxicity was evaluated by means of serial weight measurement.

RESULTS

The IC(50) values for DOX (12.1-fold) and CDDP (21.5-fold) were lower than for their liposome-encapsulated counterparts. When the two unencapsulated agents were compared, the IC(50) value for DOX was 16-fold lower than that for CDDP. In the in vivo studies, liposomes containing DTPA (PLEDTPA) exerted no effect on KB xenograft tumours when compared to untreated controls (P > 0.1). PLED was significantly more effective than DOX at doses of 2 mg/kg, 4 mg/kg and 8 mg/kg (P < 0.001 for all comparisons). At the 8 mg/kg dose, 7/13 animals treated with PLED were free of disease at 60 days, compared to 0/12 treated with DOX. PLEC displayed superior activity in comparison to CDDP at the 4 mg/kg dose level (P < 0.001), although at doses of 2 mg/kg and 10 mg/kg this comparison only reached borderline statistical significance (0.1 > P > 0.05). The highest dose level of 20 mg/kg was fatal to all animals in the CDDP group but well-tolerated by the animals in the PLEC group. On the basis of serial weight measurements, both PLED and PLEC were shown to be tolerated better than DOX and CDDP.

CONCLUSION

Both PLED and PLEC were shown to exert significant activity against head and neck xenograft tumours, with PLED showing particular efficacy.

Biodistribution and pharmacokinetics of 111In-DTPA-labelled pegylated liposomes in a human tumour xenograft model: implications for novel targeting strategies

The biodistribution and pharmacokinetics of 111In-DTPA-labelled pegylated liposomes in tumour-bearing nude mice was studied to examine possible applications of pegylated liposome-targeted anti-cancer therapies. Nude mice received an intravenous injection of 100 microl of 111In-DTPA-labelled pegylated liposomes, containing 0.37-0.74 MBq of activity. The t1/2alpha and t1/2beta of 111In-DTPA-labelled pegylated liposomes were 1.1 and 10.3 h, respectively. Tumour uptake was maximal at 24 h at 5.5 +/- 3.0% ID g(-1). Significant reticuloendothelial system uptake was demonstrated with 19.3 +/- 2.8 and 18.8 +/- 4.2% ID g(-1) at 24 h in the liver and spleen, respectively. Other sites of appreciable deposition were the kidney, skin, female reproductive tract and to a lesser extent the gastrointestinal tract. There was no indication of cumulative deposition of pegylated liposomes in the lung, central nervous system, musculoskeletal system, heart or adrenal glands. In contrast, the t1/2alpha and t1/2beta of unencapsulated 111In-DTPA were 5 min and 1.1 h, respectively, with no evidence of accumulation in tumour or normal tissues. Incubation of 111In-DTPA-labelled pegylated liposomes in human serum for up to 10 days confirmed that they are very stable, with only minor leakage of their contents. The potential applications of pegylated liposomes in the arena of targeted therapy of solid cancers are discussed.

Pegylated liposomes have potential as vehicles for intratumoral and subcutaneous drug delivery

The potential value of intratumoral or s.c. injections of pegylated liposomes as locoregionally targeted therapy of tumors and their draining lymph nodes was assessed in nude mice as part of an ongoing program aimed at developing pegylated liposomal radiosensitizers for the treatment of head and neck cancers. Animals received (111)In-labeled diethylenetriaminepentaacetic acid (DTPA), either encapsulated in pegylated liposomes (IDLPL) or in the unencapsulated form ((111)In-DTPA), as intratumoral or s.c. injections, and the local retention, locoregional nodal drainage, and systemic biodistribution were measured. After intratumoral injections, IDLPL were effectively retained in the tumor with an area under the curve (AUC) between 1 and 96 h of 2,574.4% injected dose per gram hours (%ID/g x h). The corresponding value for (111)In-DTPA was 204.4%ID/g x h. Accumulation of IDLPL was seen in ipsilateral lymph nodes. The maximal ipsilateral:contralateral node ratios were 8:1 (2.2 versus 0.27%ID/g) for inguinal nodes at 24 h and 19:1 (2.5 versus 0.13%ID/g) for axillary nodes at 48 h. Unencapsulated (111)In-DTPA showed no evidence of accumulation in locoregional nodes. After s.c. injection, IDLPL were cleared slowly from the injection site with an AUC between 1 and 192 h of 24,051.1%ID/g x h. Unencapsulated (111)In-DTPA was cleared rapidly with an AUC between 1 and 192 h of 46.4%ID/g x h. Again, significant levels of IDLPL were detected in the ipsilateral locoregional nodes, with ipsilateral:contralateral ratios of 121:1 (57.9 versus 0.48%ID/g) at 24 h (inguinal nodes) and 17:1 (5.2 versus 0.3%ID/g) at 72 h (axillary nodes). There was no retention of unencapsulated (111)In-DTPA in the draining nodes. Locoregional administration of pegylated liposomal radiosensitizers may be a useful approach for targeted therapy of head and neck tumors and their nodal metastases.

Role of adhesion molecules in bladder cancer: an important part of the jigsaw

There is a growing body of evidence suggesting that alterations in the adhesion properties of neoplastic cells may play a pivotal role in the development and progression of bladder cancer. Loss of intercellular adhesion and the desquamation of cells from the underlying lamina propria allows malignant cells to escape from their site of origin, degrade the extracellular matrix, acquire a more motile and invasive phenotype, and finally invade and metastasize. In addition to participating in tumor invasiveness and metastasis, adhesion molecules regulate or significantly contribute to a variety of functions, including signal transduction, cell growth, differentiation, site-specific gene expression, morphogenesis, immunologic function, cell motility, wound healing, and inflammation. To date, a diverse system of transmembrane glycoproteins have been identified that mediate the cell-cell and the cell-extracellular matrix adhesion. The main families of adhesion molecules are the cadherins, integrins, members of the immunoglobulin superfamily, and selectins. We review the recent data regarding the role of selected adhesion molecules in the pathogenesis of bladder cancer and their clinical exploitation as biomarkers of this malignant disease.

Beta human chorionic gonadotropin concentrations in serum of patients with pancreatic adenocarcinoma

BACKGROUND

Human chorionic gonadotropin (hCG) is normally produced and secreted by trophoblastic cells during pregnancy and from gestational trophoblastic neoplasms. It is also detected in ovarian, stomach, and colon adenocarcinomas, as well as in squamous cell carcinoma of the oesophagus. Recently, interest in its role in the pathogenesis of tumours has been enlivened after the presence of beta hCG in the cell membrane of several malignant cells was shown in vitro.

AIMS

To investigate the circulating concentrations of beta hCG in patients with exocrine pancreatic adenocarcinoma and to examine its potential prognostic value.

PATIENTS

Thirty six patients with exocrine pancreatic adenocarcinoma, 12 patients with chronic pancreatitis, and 21 healthy volunteers were studied.

METHODS

beta hCG serum concentrations were detected by the application of a radioimmunoassay technique.

RESULTS

Fifteen of 36 patients with pancreatic adenocarcinoma and only one patient with chronic pancreatitis had detectable plasma concentrations of beta hCG (p < 0.01). The patients with circulating serum titres of beta hCG had a worse outcome compared with the group of beta hCG negative patients: the difference was statistically significant (p = 0.01).

CONCLUSION

More than 40% of pancreatic exocrine tumours produce beta hCG and its production is correlated with an adverse effect on outcome.