Targeting the epigenome in malignant melanoma: Facts, challenges and therapeutic promises

Malignant melanoma is the most lethal type of skin cancer with high rates of mortality. Although current treatment options provide a short-clinical benefit, acquired-drug resistance highlights the low 5-year survival rate among patients with advanced stage of the disease. In parallel, the involvement of an aberrant epigenetic landscape, (e.g., alterations in DNA methylation patterns, histone modifications marks and expression of non-coding RNAs), in addition to the genetic background, has been also associated with the onset and progression of melanoma. In this review article, we report on current therapeutic options in melanoma treatment with a focus on distinct epigenetic alterations and how their reversal, by specific drug compounds, can restore a normal phenotype. In particular, we concentrate on how single and/or combinatorial therapeutic approaches have utilized epigenetic drug compounds in being effective against malignant melanoma. Finally, the role of deregulated epigenetic mechanisms in promoting drug resistance to targeted therapies and immune checkpoint inhibitors is presented leading to the development of newly synthesized and/or improved drug compounds capable of targeting the epigenome of malignant melanoma.

Rheumatoid nodules in thyroid gland parenchyma as an expression of rheumatoid arthritis: a case report

Background

The rheumatoid nodule is the most common extra-articular manifestation of rheumatoid arthritis. When present, it is readily identified in conventional hematoxylin and eosin sections.

Case presentation

We report a case with several rheumatoid nodules in a thyroid gland of a 33-year-old Greek woman with a 3-year history of rheumatoid arthritis treated with methotrexate, after having total thyroidectomy for hypothyroidism.

Conclusion

To the best of our knowledge, this is the first time that rheumatoid nodules have been encountered in the thyroid gland.

Prospective neoadjuvant analysis of PET imaging and mechanisms of resistance to Trastuzumab shows role of HIF1 and autophagy

Background:

Although Trastuzumab has improved survival of HER2+ breast cancer patients, resistance to the agent pre-exists or develops through the course of therapy. Here we show that a specific metabolism and autophagy-related cancer cell phenotype relates to resistance of HER2+ breast cancer to Trastuzumab and chemotherapy.

Methods:

Twenty-eight patients with locally advanced primary breast cancer were prospectively scheduled to received one cycle of Trastuzumab followed by a new biopsy on day 21, followed by taxol/Trastuzumab chemotherapy for four cycles before surgery. FDG PET/CT scan was used to monitor tumour response. Tissue samples were immunohistochemically analysed for metabolism and autophagy markers.

Results:

In pre-Trastuzumab biopsies, the LC3A+/HER2+ cell population was correlated with HIF1α expression (P=0.01), while GLUT1 and LC3B expression were correlated with Ki67 proliferation index (P=0.01 and P=0.01, respectively). FDG PET tumour dimensions before therapy were correlated with LC3B expression (P=0.005). Administration of Trastuzumab significantly reduced clinical and PET-detected tumour dimensions (P<0.01). An inverse association of tumour response with the percentage of cells expressing HIF1α at baseline was documented (P=0.01). Administration of Trastuzumab resulted in a decrease of the proliferation index (P=0.004), GLUT1 (P=0.04) and HER2 (P=0.01) expression. In contrast, the percentage of LC3A+/HER2+ cells was increased (P=0.01). High baseline HIF1α expression was the only parameter associated with poorer pathological response to preoperative chemotherapy (P=0.001).

Conclusions:

As the HER2+/LC3A+ phenotype, which often overexpresses HIF1α, is a major subpopulation increasing after therapy with Trastuzumab, LC3A- and HIF1α-targeting therapies should be investigated for the augmentation of anti-HER2 therapy efficacy.

Lactate dehydrogenase 5 isoenzyme overexpression defines resistance of prostate cancer to radiotherapy

Background:

Radiotherapy provides high-cure rates in prostate cancer. Despite its overall slow clinical growth, high proliferation rates documented in a subset of tumours relate to poor radiotherapy outcome. This study examines the role of anaerobic metabolism in prostate cancer growth and resistance to radiotherapy.

Methods:

Biopsy samples from 83 patients with prostate cancer undergoing radical hypofractionated and accelerated radiotherapy were analysed for MIB1 proliferation index and for lactate dehydrogenase isoenzyme LDH5, a marker of tumour anaerobic metabolism. Ninety-five surgical samples were in parallel analysed. Correlation with histopathological variables, PSA and radiotherapy outcome was assessed. Dose–response experiments were performed in PC3 and DU145 cancer cell lines.

Results:

High MIB1 index (noted in 25% of cases) was directly related to Gleason score (P<0.0001), T3-stage (P=0.0008) and PSA levels (P=0.03). High LDH5 (noted in 65% of cases) was directly related to MIB1 index (P<0.0001), Gleason score (P=0.02) and T3-stage (P=0.001). High Gleason score, MIB1, LDH5 and PSA levels were significantly related to poor BRFS (P=0.007, 0.01, 0.03 and 0.01, respectively). High Gleason score (P=0.04), LDH5 (P=0.01) and PSA levels (P=0.003) were significantly related to local recurrence. MIB1 and T-stage did not affect local control. Silencing of LDHA gene in both prostate cancer cell lines resulted in significant radiosensitisation.

Conclusions:

LDH5 overexpression is significantly linked to highly proliferating prostate carcinomas and with biochemical failure and local relapse following radiotherapy. Hypoxia and LDHA targeting agents may prove useful to overcome radioresistance in a subgroup of prostate carcinomas with anaerobic metabolic predilection.

Autophagy and hypoxia in colonic adenomas related to aggressive features

AIM

The study investigated whether autophagic activity and hypoxia parallel the adenoma-carcinoma sequence.

METHOD

The study comprised 120 tubular adenomas with high-grade dysplasia, including 22 with questionable evidence of invasion, 37 with definite stromal invasion and 29 with severely dysplastic adenoma, 10 traditional serrated adenomas and 22 classical tubular adenomas lacking aggressive features. The samples were stained immunohistochemically for autophagy (LC3A and Beclin-1) and hypoxia-inducible factor1-alpha (HIF1α) markers.

RESULTS

LC3A was detected as diffuse cytoplasmic staining and as dense "stone-like" structures (SLS) within cytoplasmic vacuoles. Beclin-1 reactivity was purely cytoplasmic, whereas that of HIF1α was both cytoplasmic and nuclear. SLS counts in noninvasive, nontransformed areas of tubular adenomas were consistently low (median SLS = 0.5; 200× magnification), whereas a progressive increase was noted from areas of equivocal invasion (median SLS = 1.3; 200× magnification) and intramucosal carcinoma (median SLS = 1.4; 200× magnification) to unequivocal invasive foci (median SLS = 2.1; 200× magnification) (P < 0.0001). A similar association was shown for Beclin-1 and HIF1α expression (P < 0.05). Traditional serrated adenomas yielded low SLS counts and weak HIF1α reactivity, but high cytoplasmic LC3A and Beclin-1 expression (P < 0.01).

CONCLUSION

A hypoxia-driven autophagy in adenomatous polyps, when particularly intense and localized, is commonly associated with early invasion or severely dysplastic adenoma.

Radiation damage and radioprotectants: new concepts in the era of molecular medicine

Exposure to ionising radiation results in mutagenesis and cell death, and the clinical manifestations depend on the dose and the involved body area. Reducing carcinogenesis in patients treated with radiotherapy, exposed to diagnostic radiation or who are in certain professional groups is mandatory. The prevention or treatment of early and late radiotherapy effects would improve quality of life and increase cancer curability by intensifying therapies. Experimental and clinical data have given rise to new concepts and a large pool of chemical and molecular agents that could be effective in the protection and treatment of radiation damage. To date, amifostine is the only drug recommended as an effective radioprotectant. This review identifies five distinct types of radiation damage (I, cellular depletion; II, reactive gene activation; III, tissue disorganisation; IV, stochastic effects; V, bystander effects) and classifies the radioprotective agents into five relevant categories (A, protectants against all types of radiation effects; B, death pathway modulators; C, blockers of inflammation, chemotaxis and autocrine/paracrine pathways; D, antimutagenic keepers of genomic integrity; E, agents that block bystander effects). The necessity of establishing and funding central committees that guide systematic clinical research into evaluating the novel agents revealed in the era of molecular medicine is stressed.

Long-term survival of a patient with multiple abdominal metastasis from endometrial carcinoma treated with multi-portal conformal re-irradiation and chemotherapy

A patient with recurrent endometrial cancer with multiple abdominal and pelvic tumoral masses was treated with re-irradiation combined with liposomal doxorubicin and oxaliplatin. A multiple field conformal technique was used to deliver a highly accelerated and hypofractionated scheme (15 fractions of 3.5 Gy, within 19 days). Complete response was confirmed four months after therapy. Four years later a lung metastasis appeared and was again treated with a similar course of therapy, once again resulting in a complete response. It is suggested that in the era of modern image-guided radiotherapy patients with endometrial cancer who have relapsed within or outside the loco-regional area, should be carefully assessed for an eventual gross tumor eradication using high-dose localized radiotherapy, leaving as the only target of chemotherapy the microscopic undetectable disease.

Angiogenesis and angiogenic factor expression in thyroid cancer

PURPOSE

Increased expression of angiogenic factors and high vascular density characterize tumors with increased invasive and metastatic capability. Anti-vascular endothelial growth factor (VEGF) therapies have shown an important potentiation of chemotherapy and radiotherapy in experimental and clinical studies. The purpose of this study was to investigate whether it could be possible to identify a subgroup of thyroid cancer patients with high angiogenic activity.

METHODS

Formalin-fixed paraffin-embedded tissues from 25 papillary and 18 follicular thyroid carcinomas were assessed immunohistochemically for angiogenic activity, i.e. vascular density (VD) and expression of VEGF and basic fibroblast growth factor (bFGF).

RESULTS

VD was significantly higher in follicular tumors (p=0.05). Tumors > 4 cm had a significantly higher VD (p=0.001). High VEGF expression was significantly related to high VD (p=0.05). There was no association of bFGF with histological characteristics.

CONCLUSIONS

Increased angiogenic activity is a common feature of thyroid carcinomas, particularly in follicular tumors and larger carcinomas. These results support the testing of anti-VEGF therapies in combination with radiotherapy and chemotherapy in advanced thyroid tumors.

Activated VEGFR2/KDR pathway in tumour cells and tumour associated vessels of colorectal cancer

BACKGROUND

Vascular endothelial cell growth factor (VEGF) acts by phosphorylating specific tyrosine kinase receptors on endothelial cell membrane promoting angiogenesis. The study of the activation status of VEGF receptors in human malignancies has recently become feasible by means of specific monoclonal antibodies recognising the phosphorylated form of these receptors.

MATERIALS AND METHODS

In the current study, we investigate the expression of the phosphorylated VEGFR2/KDR receptor in normal colon and colorectal adenocarcinomas in parallel with histopathological parameters, prognosis and the expression of the 'hypoxia inducible factor' HIF1alpha.

RESULTS

pVEGFR2/KDR was weakly expressed in the normal colon, but it was expressed strongly in the cytoplasm and nuclei of cancer cells and in the tumour associated vasculature, mainly at the invading tumour edge. pVEGFR2/KDR expression in cancer cells was significantly associated with a tumour diameter > 6 cm (P = 0.04), poor histological differentiation (P = 0.004) and with high CEF1alpha expression (P = 0.05). High pVEGFR2/KDR expressing vascular density was significantly related with a high VEGF and HIF1alpha expression in cancer cells (P = 0.02 and 0.03, respectively). This was also related significantly to high pVEGFR2/KDR expression in cancer cells. In multivariate analysis, the most significant predictors for death were lympho-vascular invasion (P < 0.001) followed by VEGF (P = 0.014), node status (P = 0.015), standard vascular density (P = 0.022) and necrosis (P = 0.032).

CONCLUSIONS

pVEGFR2 receptors are largely expressed in colon cancer cells and intratumoural vasculature. As VEGF targeting agents enter the clinical practice, the role of monoclonal antibodies recognising the phosphorylated form of VEGF receptors as predictors of response to targeted therapies should be sought in clinicopathological trials.

BNIP3 expression in endometrial cancer relates to active hypoxia inducible factor 1alpha pathway and prognosis

AIMS

BNIP3 is a pro-apoptotic mitochondrial protein induced under hypoxic stress, with the BNIP3 gene being under direct regulation of the hypoxia-inducible HIF-1alpha transcription factor. Induction of BNIP3 leads to caspase-independent necrosis-like cell death and an aggressive tumour phenotype. The role of BNIP3 in endometrial cancer was examined.

METHODS

The immunohistochemical patterns of BNIP3 expression in 72 early endometrial adenocarcinomas of the endometrioid cell type were studied. Correlation of BNIP3 with the hypoxia-inducible factor HIF-1alpha pathway and with prognosis was also examined.

RESULTS

BNIP3 was strongly and extensively expressed in the cytoplasm of cancer cells in 23/72 (31.9%) cases. This high BNIP3 reactivity was not related to histological grade, depth of myometrial invasion or steroid hormone receptor expression. There was, however, a significant association of BNIP3 reactivity with HIF-1alpha (p = 0.04), VEGF (p = 0.04) and, particularly, LDH-5 expression (p = 0.0001). Furthermore, high BNIP3 was associated with poor survival in both univariate (p = 0.05) and multivariate (p = 0.03) models.

CONCLUSION

BNIP3 seems to be an important hypoxia-regulated molecule involved in endometrial cancer pathology. Given that high BNIP3 reactivity, being linked with poor post-operative outcome, has been linked with a favourable response to cytotoxic therapy (as previously indicated in experimental studies), high BNIP3 expression may be an indicator for adjuvant chemoradiotherapy in stage I endometrial carcinomas.

Squamous cell nose and a synchronous in-situ vocal cord carcinoma: a case report

Reports indicate that the incidence of multiple primary tumours in head and neck cancers is high. However, most of these tumours are either metachronous primary or secondary tumours of the same histopathological type. The development of a synchronous primary squamous cell skin cancer of the nose and an in-situ vocal cord carcinoma is something unusual. We present the case of a patient with a primary neoplasm along the lateral side of the nose up to the bone of the pyramid, including the skin of the inner side of the nose and an infiltration of the inferior nasal concha on the right side, together with a small synchronous primary lesion of the left vocal cord. To the best of our knowledge the case described is the first in the English medical literature and we discuss the complete management of synchronous head and neck malignancies, emphasising the importance of panendoscopy in the prevention of pitfalls in diagnosis and the therapeutic procedure.

Hypoxia inducible factors 1alpha and 2alpha are associated with VEGF expression and angiogenesis in gallbladder carcinomas

AIMS

To investigate the significance of the hypoxia inducible factors HIF-1alpha and HIF-2alpha in gallbladder adenocarcinomas and their relation to angiogenesis and to the expression of VEGF, an angiogenic factor transcriptionally regulated by HIFalphas.

METHODS

HIF-1alpha and 2alpha expression was assessed immunohistochemically in 60 patients with early gallbladder adenocarcinomas, treated with surgery alone. In addition, the vascular density (VD) and the expression of the angiogenic factors VEGF and thymidine phosphorylase (TP) were examined. The results were correlated with clinico-pathological features and prognosis.

RESULTS

Overexpression of HIF-1alpha and 2alpha was significantly associated with increased tumor angiogenesis and VEGF expression, while HIF-2alpha was linked with upregulation of TP. None of these factors were associated with T-stage and tumor grade. Although HIFs did not relate significantly with prognosis, patients with HIF-1/2 expression who failed to switch-on VEGF or intratumoral angiogenesis had a favorable outcome.

CONCLUSION

Hypoxia inducible factors are upregulated in a large proportion of gallbladder adenocarcinomas, a feature strongly related to increased expression of VEGF and intensified angiogenesis.

Proliferating fibroblasts at the invading tumour edge of colorectal adenocarcinomas are associated with endogenous markers of hypoxia, acidity, and oxidative stress

BACKGROUND

Stroma frequently forms at sites of active tumour invasion, and may be important for tumour growth and progression. The term "stromatogenesis" is used to describe this unique process that involves host peritumorous fibroblasts and is very different to reactive fibrosis.

AIMS/METHODS

To investigate the activation status of host fibroblasts at the invading tumour edge, assessed as MIB1 proliferation index and thymidine phosphorylase (TP) expression. Results were related to vascular density and certain properties of invading cancer cells-MIB1 proliferation activity, TP expression, expression of endogenous markers of hypoxia (hypoxia inducible factor-1alpha; HIF1alpha) and acidity (lactate dehydrogenase-5; LDH5). Standard immunohistochemical techniques were applied to 150 colorectal adenocarcinomas.

RESULTS

Normal fibroblasts at the tumour edge had a median MIB1 index of 2%-significantly higher than normal submucosal fibroblasts (0.3%) and significantly lower than cancer cells (40%). Normal peritumorous fibroblasts with a proliferation rate above the median strongly expressed TP and were supported by an increased vascular network. Cancer cells close to these fibroblasts had a high MIB1 proliferative index, high HIF1alpha and LDH5 reactivity, and a clear trend to extramural extension. All associations were significant.

CONCLUSIONS

These results suggest that activated fibroblastic status at the invading tumour front sets the stage for stromatogenesis and new blood vessel formation, facilitating deep transmural invasion in colorectal adenocarcinomas. This complicity of peritumorous fibroblasts in the overall aggressiveness/invasive and metastatic ability of colorectal tumours, occurring within the framework of cancer-stromal cell interactions, is probably favoured by the altered microenvironmental conditions of hypoxia and acidity.

LYVE-1 immunohistochemical assessment of lymphangiogenesis in endometrial and lung cancer

AIMS/METHODS

Normal and malignant pulmonary and endometrial tissues were analysed for lymphatic vessels to assess the process of lymphangiogenesis and its role at these sites, using specific immunostaining for LYVE-1 and the panendothelial marker CD31.

RESULTS

Lymphatics were clearly demonstrated in some normal tissues (myometrium, bronchial submucosa, and intestinal submucosa), but not in others (endometrium and alveolar tissue). LYVE-1 positive lymphatic vessels were detected at the tumour periphery of endometrial and lung carcinomas, but not within the main tumour mass. Double staining for LYVE-1 and the MIB1 proliferation marker revealed a higher proliferation index in lymphatic endothelial cells at the invading front of endometrial carcinomas, compared with myometrial areas distal to the tumour. Lung and endometrial carcinomas did not have an intratumorous lymphatic network.

CONCLUSIONS

Although lymphangiogenesis may occur at the invading tumour front, incorporated lymphatics do not survive. Therefore, the dissemination of cancer cells through the lymphatics may occur by invasion of peripheral cancer cells into the adjacent normal lymphatics, or through shunts eventually produced at the invading tumour front as a consequence of active angiogenesis and lymphangiogenesis.

Angiogenesis and vascular survival ability in ovarian adenocarcinomas

This study was designed to investigate the prognostic relevance of ovarian tumour angiogenesis in terms of tumour angiogenic activity (TAA) and vascular survival ability (VSA), i.e. the ability of newly formed vessels to survive once incorporated into the main tumour mass. TAA was assessed at the edge of the invading tumour, while VSA was evaluated in inner tumour areas, always in comparison with the invading edge. A series of 46 ovarian grade-1 adenocarcinomas of the endometrioid and the serous cell type was assessed. Endothelial cells were revealed after using a standard immunohistochemical technique and the CD31 antibody. Vascular density was, in general, higher at the periphery of the tumour than in the inner tumour areas, although in both cases, a rich vascular supply was associated with a poor survival. By combining counts at the tumour edge versus inner tumour areas (edvin), four groups of tumour vascularity emerged: edvin type 1 (low TAA/low VSA), edvin type 2 (low TAA/high VSA), edvin type 3 (high TAA/low VSA) and edvin type 4 (high TAA/high VSA). Edvin type-4 tumours were related to the most unfavourable prognosis. It is concluded that VSA and TAA are complementary procedures in assessing ovarian tumour vasculature and, therefore, prognosis, and by combining the two parameters, a more precise impression of the state of vascularisation in the ovary is obtained, which may prove useful in designing anti-angiogenic therapies.

Tumour angiogenic activity and vascular survival ability in bladder carcinoma

BACKGROUND

Tumour angiogenic activity (TAA) is an important prognostic factor in many human tumours, including transitional cell carcinomas of the urinary bladder. The new tumour vessels are formed in the invading tumour front. This peripheral tumour area is internalised as soon as the growing tumour forms a new front.

AIMS

To investigate and compare TAA with the ability of the tumour vasculature to survive (VSA) in inner tumour areas.

METHODS

Fifty one cystectomy specimens with transitional cell carcinoma of the urinary bladder were studied. Sections were stained immunohistochemically for endothelial cells and proliferation activity, using the monoclonal antibodies CD31 and MIB-1, respectively. TAA was studied at the invading tumour edge-designated as the mean number of blood vessels in three "hot spots" at this site. VSA was assessed by comparing the vascular density in peripheral and inner tumour areas.

RESULTS

High TAA at the invading tumour edge significantly correlated with lymph node involvement, but not with patient survival. Extensive lymphocytic infiltration was more frequent in tumours with high TAA. VSA was significantly higher in tumours of high proliferation index, high histological grade, advanced T stage, and poor prognosis. However, there was no association with metastasis to regional lymph nodes.

CONCLUSION

VSA and TAA provide a more complete profile of the tumour vasculature and are associated with aggressive tumour behaviour in transitional cell carcinomas of the urinary bladder. The qualitative information provided by VSA may be important for the identification of angiogenic tumours with differential responses to various antiangiogenic treatments.

Vascular endothelial growth factor (VEGF) expression in operable gallbladder carcinomas

AIM

To investigate the angiogenic and prognostic role of vascular endothelial growth factor (VEGF) in operable gallbladder carcinomas.

METHODS

Sixty patients with early gallbladder carcinomas, treated with surgery alone, were investigated immunohistochemically for the expression of VEGF, thymidine phosphorylase (TP) and new blood vessel formation. The results were correlated with clinico-pathological features and prognosis.

RESULTS

An increased VEGF secretion in gallbladder carcinomas was significantly associated with increased angiogenesis but not with patients survival, although high angiogenesis did relate with poor prognosis. TP was also associated with angiogenesis, but only the combined VEGF/TP expression was associated with unfavourable survival. Histological grade was another independent factor of prognosis.

CONCLUSION

Both VEGF and TP expression are associated with high rate of angiogenesis, a factor directly associated with prognosis. The combined expression of these angiogenic factors confer a particularly poor post-operative outcome, speculature.

Lactate dehydrogenase-5 (LDH-5) overexpression in non-small-cell lung cancer tissues is linked to tumour hypoxia, angiogenic factor production and poor prognosis

Lactate dehydrogenase-5 (LDH-5) catalyses the reversible transformation of pyruvate to lactate, having a principal position in the anaerobic cellular metabolism. Induction of LDH-5 occurs during hypoxia and LDH-5 transcription is directly regulated by the hypoxia-inducible factor 1 (HIF1). Serum LDH levels have been correlated with poor prognosis and resistance to chemotherapy and radiotherapy in various neoplastic diseases. The expression, however, of LDH in tumours has never been investigated in the past. In the present study, we established an immunohistochemical method to evaluate the LDH-5 overexpression in tumours, using two novel antibodies raised against the rat muscle LDH-5 and the human LDH-5 (Abcam, UK). The subcellular patterns of expression in cancer cells were mixed nuclear and cytoplasmic. In direct contrast to cancer cells, stromal fibroblasts were reactive for LDH-5 only in a minority of cases. Serum LDH, although positively correlated with, does not reliably reflect the intratumoral LDH-5 status. Lactate dehydrogenase-5 overexpression was directly related to HIF1alpha and 2alpha, but not with the carbonic anhydrase 9 expression. Patients with tumours bearing high LDH-5 expression had a poor prognosis. Tumours with simultaneous LDH-5 and HIF1alpha (or HIF2alpha) overexpression, indicative of a functional HIF pathway, had a particularly aggressive behaviour. It is concluded that overexpression of LDH-5 is a common event in non-small-cell lung cancer, can be easily assessed in paraffin-embedded material and provides important prognostic information, particularly when combined with other endogenous markers of hypoxia and acidity.

Molecular analysis of local relapse in high-risk breast cancer patients: can radiotherapy fractionation and time factors make a difference?

Large primary breast tumours and extensive lymph node involvement are linked to a high rate of local recurrence after surgery. In 10-20% of such high-risk breast cancer patients, local relapse will occur despite postoperative radiotherapy. In the present study, we investigated whether molecular features, such as angiogenesis, cancer cell proliferation, steroid receptor expression, c-erbB-2 oncoprotein overexpression, p53 protein nuclear accumulation or bcl-2 antiapoptotic protein expression, can predict failure of local therapy. We further examined as to which subgroups of patients could benefit from altered fractionation schemes of radiotherapy. In univariate analysis, high intratumoural angiogenesis, c-erbB overexpression and mutant-p53 nuclear accumulation were significantly associated with increased relapse rate (P=0.0002, 0.009 and 0.05, respectively). In multivariate analysis, the microvessel density and the c-erbB-2 status were independent and significant factors related to local relapse (P=0.001, t-ratio 3.36 and P=0.02, t-ratio 2.26, respectively). Hypofractionated and accelerated radiotherapy supported with amifostine (HypoARC regimen) was significantly more effective than standard radiotherapy in cases with high cancer cell proliferation index, c-erbB-2 and p53 overexpression. High angiogenesis, however, was linked with local relapse regardless of the radiotherapy regimen.

Hypoxia inducible factor 1alpha and 2alpha overexpression in inflammatory bowel disease

AIMS

Hypoxia inducible factors 1alpha and 2alpha (HIF1alpha and HIF2alpha) are hypoxia regulated transcriptional factors, which control the expression of a variety of genes responsible for angiogenesis, glycolysis, and the inhibition of apoptosis. Because angiogenesis and tissue regeneration are integral components of the inflammatory process, this study was designed to investigate the role of HIFalpha molecules in inflammatory bowel disease.

METHODS

Surgical specimens from patients with active ulcerative colitis (UC) and Crohn's disease (CD) were assessed immunohistochemically for HIF1alpha and HIF2alpha reactivity, and the expression of these molecules was compared with the expression of the angiogenic factors thymidine phosphorylase (TP), vascular endothelial growth factor (VEGF), and VEGF-KDR activated vasculature. The vascular density of the lesions was also assessed using anti-CD31 immunostaining.

RESULTS

HIF1alpha was expressed focally (epithelial cells, stromal fibroblasts, and myocytes) in both UC and CD, whereas HIF2alpha was expressed focally in UC and diffusely in CD. TP expression was uniformly positive in both diseases. VEGF expression was absent in CD, and weakly positive in UC. The VEGF-KDR reactivity of the submucosal vasculature was only slightly increased in UC and CD compared with normal tissue. The inflammatory cells stained with HIF2alpha and TP in all cases, but the reactivity was generalised in CD and focal in UC. In both diseases, vascular density was significantly higher than that seen in normal tissue.

CONCLUSIONS

The discordant expression of HIF2alpha and VEGF in CD suggests an inherent deficiency of the intestine to respond to various stresses by the induction of VEGF. This finding should be investigated further.

Hypoxia inducible factor 1 alpha and 2 alpha expression is independent of anemia in patients with stage I endometrial cancer

OBJECTIVE

To investigate whether anemia, a putative factor counteracting the efficacy of radiotherapy, up-regulates the endogenous markers of intratumoral hypoxia, the hypoxia inducible factors HIF1 alpha and HIF2 alpha.

MATERIALS AND METHODS

Forty-two hysterectomy specimens harboring endometrial adenocarcinomas of the endometrioid cell type, stage I were investigated immunohistochemically for the expression of HIF1 alpha, HIF2 alpha and the down-stream inducible expression of vascular endothelial growth factor VEGF. The results were correlated with hemoglobin (Hb) levels.

RESULTS

There was no significant association between Hb levels and the expression of HIF1 alpha, HIF2 alpha or VEGF in our material.

CONCLUSION

Activation of hypoxia pathways is an intrinsic self-regulated process, independent of Hb levels in endometrial adenocarcinomas. Other factors such as microvessel density (MVD), vessel/tumor cell distance or genetic events may be important.

Concurrent administration of Docetaxel and Stealth liposomal doxorubicin with radiotherapy in non-small cell lung cancer : excellent tolerance using subcutaneous amifostine for cytoprotection

The substantial augmentation of the radiation sequelae during chemo-radiotherapy with novel drugs masks the real potential of such regimens. In this study we examined whether subcutaneous administration of amifostine can reduce the toxicity of a highly aggressive chemo-radiotherapy scheme with Stealth liposomal doxorubicin (Caelyx and Docetaxel (Taxotere in non-small cell lung cancer. Twenty-five patients with stage IIIb non-small cell lung cancer were recruited in a phase I/II dose escalation trial. The starting dose of Taxotere was 20 mg m(-2) week and of Caelyx was 15 mg m(-2) every two weeks, during conventionally fractionated radiotherapy (total dose of 64 Gy). The dose of Taxotere/Caelyx was, thereafter, increased to 20/25 (five patients) and 30/25 mg m(-2) (15 patients). Amifostine 500 mg was given subcutaneously before each radiotherapy fraction, while an i.v. amifostine dose of 1000 mg preceded the infusion of docetaxel. The 'in-field' radiation toxicity was low. Grade 3 esophagitis occurred in 9 out of 25 (36%) patients. Apart from a marked reduction of the lymphocyte counts, the regimen was deprived from any haematological toxicity higher than grade 1. No other systemic toxicity was noted. The CR and CR/PR rates in 15 patients treated at the highest dose level was 40% (6 out of 15) and 87% (13 out of 15) respectively. It is concluded that the subcutaneous administration of amifostine during high dose Taxotere/Caelyx chemo-radiotherapy is a simple and effective way to render this aggressive regimen perfectly well tolerated, by reducing the systemic and the 'in-field' toxicity to the levels expected from simple conventional radiotherapy. The impressive tolerance and the high CR rate obtained encourages the conduct of a relevant randomized trial to assess an eventual survival benefit in patients with non-small cell lung cancer.

Thymidine phosphorylase expression in normal, hyperplastic and neoplastic prostates: correlation with tumour associated macrophages, infiltrating lymphocytes, and angiogenesis

Thymidine phosphorylase is an angiogenic factor primarily expressed by cancer cells, stromal cells and tumour-associated macrophages in many human malignancies. These different types of thymidine phosphorylase-expressing cells, however, may have a distinct place in the angiogenic process, and this question was addressed in the present study. A series of 20 normal/hyperplastic prostate glands and 60 prostate carcinomas was investigated by immunohistochemistry, using specific antibodies for thymidine phosphorylase (P-GF.44C), tumour-associated macrophages (CD68), endothelium (CD31) and prostate specific antigen (ER-PR8). Thymidine phosphorylase expression by normal and hyperplastic epithelial or stromal cells occurred almost exclusively in the context of an intense lymphocytic infiltrate. High thymidine phosphorylase cancer cells and thymidine phosphorylase stromal cells expression was associated with high angiogenesis in prostate carcinomas, and this significant association was extended to include both tumour-associated macrophages and tumour-infiltrating lymphocytes. Thymidine phosphorylase expression and tumour-infiltrating lymphocytes were related inversely with prostate specific antigen reactivity. In conclusion, thymidine phosphorylase is a major angiogenic factor in prostate carcinomas and its up-regulation is likely to occur in the context of a host immune response.

Amifostine in clinical oncology: current use and future applications

Amifostine (Ethyol), an inorganic thiophosphate, is a selective broad-spectrum cytoprotector of normal tissues that provides cytoprotection against ionizing radiation and chemotherapeutic agents, thus preserving the efficacy of radiotherapy and chemotherapy. This review summarizes the preclinical data and clinical experience with amifostine, and provides insight into future clinical directions. Amifostine, an inactive pro-drug, is transformed to an active thiol after dephosphorylation by alkaline phosphatase found in the normal endothelium. The absence of alkaline phosphatase in the tumoral endothelium and stromal components, and the hypovascularity and acidity of the tumor environment, may explain its cytoprotective selectivity. The cytoprotective mechanism of amifostine is complicated, involving free radical scavenging, DNA protection and repair acceleration, and induction of cellular hypoxia. Intravenous administration of amifostine 740-900 mg/m(2) before chemotherapy and 250-350 mg/m(2) before each radiotherapy fraction are widely used regimens. The US Food and Drug Administration has approved the use of amifostine as a cytoprotector for cisplatin chemotherapy and for radiation-induced xerostomia. Ongoing trials are being conducted to determine the efficacy of amifostine in reducing radiation-induced mucositis and other toxicities. Novel schedules and routes of administration are under investigation, and may further simplify the use of amifostine and considerably broaden its applications.

Diminutive polyps of large bowel should be an early target for endoscopic treatment

BACKGROUND AND AIMS

Aim of the present study is to ascertain the importance of diminutive colorectal polyps and define the need for removal according to their characteristics and malignant potential.

PATIENTS AND METHODS

A total of 4,723 patients who underwent colonoscopy were evaluated and 624 patients with 826 polyps were recorded. There were 352 patients with 443 diminutive polyps, studied according to their distribution. Of these, 371 were removed, histologically examined and correlated to patient characteristics and occurrence of synchronous neoplasms.

RESULTS

Of the right colon polyps, 81/115 were diminutive, versus 362/711 of the left colon (p<0.0001). Adenomas were more common in patients over 50 years of age, (p<0.0001). In all colonic segments, diminutive adenomas prevailed over hyperplastic polyps, whereas the proportion of diminutive adenomas predominated in the right colon (p=0.0015). Adenomas were classified as tubular 39%, tubulovillous 55.7% and villous 5.3%. The degree of dysplasia was mild in 45.5%, moderate in 51% and severe in 3.5%. The prevalence of synchronous neoplasms was 37.4%. They were more frequently found in males over 50 years of age and in patients with diminutive adenomas compared to those with diminutive hyperplastic polyps (p=0.0078).

CONCLUSIONS

The majority of right colon polyps are diminutive. The proportion of diminutive adenomas is higher in patients over 50 years and in the right vs left colon. Diminutive polyps should be removed taking into account the high prevalence of adenomas with a villous component and their significant degree of dysplasia.

Prognostic role of angiogenesis in operable carcinoma of the gallbladder

The prognostic significance of intratumoral angiogenesis was investigated in 62 patients with stage I-III carcinomas of the gallbladder treated with simple cholecystectomy. Microvessel density (MVD) was assessed immunohistochemically, using the alkaline phosphatase/anti-alkaline phosphatase method and the monoclonal antibody CD31. The mean MVD was 30.5 vessels per x 200 optical field. Using the thirty-third and the sixty-sixth percentile, the patients were grouped into three MVD categories: low (MVD 9-18; 20 patients), medium (MVD 19-31; 20 patients), and high (MVD 32-86; 22 patients). A high MVD was more frequent in well-differentiated adenocarcinomas compared with moderately and poorly differentiated tumors (p = 0.04), but there was no statistically significant association between MVD and T stage, or patients' age or sex. Multivariate analysis, including MVD, T stage, and histologic grade, showed that MVD was a significant independent prognostic factor in carcinomas of the gallbladder (p = 0.001, t ratio 3.3). It is believed that the assessment of intratumoral angiogenesis in patients with operable gallbladder carcinomas may be useful in predicting prognosis and, perhaps, in decision making for postoperative adjuvant treatment.

Patterns of episialin/MUC1 expression in endometrial carcinomas and prognostic relevance

AIMS

To investigate episialin/MUC1 expression in the normal, hyperplastic and neoplastic endometrium, and relate patterns of tumour MUC1 reactivity with histopathological characteristics, oestrogen and progesterone receptor (ER and PR) status, bcl-2 and p53 oncoproteins and with clinical behaviour.

METHODS AND RESULTS

We studied 42 normally cycling endometria, 45 endometrial hyperplasias of various forms, and 111 endometrial carcinomas of endometrioid and non-endometrioid cell types with specific monoclonal antibodies employing standard immunohistochemical techniques. The follow-up period ranged from 34 to 182 months with a median of 86 months. Epithelial mucin episialin/MUC1 was consistently expressed in the normal endometrium, following a cyclical pattern: "apical membrane staining" in early and mid-proliferative endometrium; "purely cytoplasmic staining" in late proliferative endometrium; and "cytoplasmic staining with intraluminal secretions" in secretory endometrium. Immunostaining patterns in simple and complex hyperplasia were similar to late proliferative endometrium, while atypical hyperplasias and endometrial carcinomas either simulated patterns of proliferative endometrium or lacked MUC1 reactivity. Membranous MUC1 positivity was statistically more frequent in endometrioid carcinomas compared with carcinomas of non-endometrioid type (P = 0.006). Cytoplasmic MUC1 positivity was significantly associated with poor prognosis, while MUC1-negative carcinomas were associated with PR expression and an improved survival (P=0.04). There was no association of MUC1 patterns with bcl-2 and p53 immunoreactivity or with other histopathological variables.

CONCLUSIONS

Episialin/MUC1 is an integral component of the normal premenopausal endometrium and is probably hormonally regulated. It is frequently expressed in endometrial hyperplasias and carcinomas. The loss of MUC1 expression from endometrial carcinomas is associated with a favourable prognosis.

Towards a biological staging model for operable non-small cell lung cancer

Non-small cell lung cancer is the most common cause of cancer-related death in North America and Europe. Despite improvements in the diagnosis and treatment of the disease the prognosis remains poor, the overall 5-year survival being 4-14%. An increased understanding of the molecular biology of the disease may identify novel targets for drug development. We evaluated epidermal growth factor receptor (EGFR), HER-2/neu, matrix metalloproteinase (MMP)-2, MMP-9, p53 and bcl-2 expression and microvessel density (MVD) in patients who underwent surgery with curative intent in our department between 1991 and 1996. Co-expression of EGFR/MMP-9, MVD and bcl-2 were found to be independent prognostic variables, which allowed prediction of patient outcome independent of surgical stage. Other prognostic factors identified in our series were gender, surgical stage, platelet count, extent of necrosis, the hypoxia marker carbonic anhydrase-9 and beta-catenin. In collaboration with groups in Oxford and Greece, we were also able to establish the angiogenic growth factors vascular endothelial growth factor and platelet-derived endothelial growth factor as prognostic variables. The inter-relationships between these factors are currently being examined in an expanded patient series. Through this work we hope to be able to construct an integrated biological prognostic model which can be tested in prospective studies. This work has identified several potential targets for novel therapeutic agents currently in development.

The angiogenic "vascular endothelial growth factor/flk-1(KDR) receptor" pathway in patients with endometrial carcinoma: prognostic and therapeutic implications

BACKGROUND

Vascular endothelial growth factor (VEGF) is an important endothelial cell mitogen associated with increased angiogenesis and aggressive tumor behavior. Its stimulating effect on endothelial cells basically is dependent on the presence of specific VEGF receptors, such as the flk-1(KDR) receptor. This study investigates the roles of VEGF and of a functionally intact angiogenic pathway, "VEGF/flk-1(KDR)," in patients with endometrial carcinoma and their significance in prognosis and therapy.

METHODS

A series of 121 endometrial carcinomas were studied. The expression of VEGF by endometrial tumor cells was assessed using the monoclonal antibody (MoAb) VG1. VEGF/KDR complexes on tumor endothelium or activated microvessel density (aMVD) were identified using the MoAb 11B5. In addition, the standard microvessel density (sMVD) was assessed with anti-CD31. In all tumors, the alkaline phosphatase/antialkaline phosphatase technique was employed. A Fisher exact test or an unpaired, two-tailed t test was used for testing correlations between categoric tumor variables, whereas a log-rank test was used to determine statistical differences between life tables. A Cox proportional hazards model was used to assess the effect of tumor variables on overall survival.

RESULTS

Cytoplasmic VEGF expression in > 50% of tumor cells was associated significantly with aMVD (P < 0.0001) and with sMVD (P < 0.003). In univariate survival analysis, VEGF (P = 0.0002), aMVD (P = 0.001), and sMVD (P = 0.0009) were significant prognostic variables. Equally important were the histologic parameters tumor type (P = 0.03), tumor grade (P = 0.003), and disease stage (P < 0.0001). In multivariate analysis, disease stage was the most important independent prognostic factor (P < 0.0001), followed by VEGF/KDR (P < 0.01), and VEGF (P < 0.04). Furthermore, VEGF and VEGF/KDR were the only independent prognostic variables for patients with Stage I endometrioid adenocarcinoma.

CONCLUSIONS

sMVD and the angiogenic factor VEGF are important indicators of a poor prognosis in patients with endometrial carcinoma. VEGF/KDR complexes define a subgroup of patients with endometrial carcinoma with an even worse prognosis.

Squamous cell head and neck cancer: evidence of angiogenic regeneration during radiotherapy

BACKGROUND AND PURPOSE

Intra-tumoural neoangiogenesis is an essential process for tumour progression. Although intensification of angiogenic pathways during cytotoxic therapy has been reported by a few experimental studies, the role of angiogenesis in response to radiotherapy is unclear. We recently reported an adverse effect of intense angiogenesis in the radiotherapy outcome of squamous cell head and neck cancer (SCHNC). In the present study we investigated the radiotherapy-induced changes in the microvessel density (MVD) and in the expression of the angiogenic factor thymidine phosphorylase (TP) in SCHNC.

PATIENTS AND METHODS

Twenty-four patients with SCHNC underwent a biopsy of the primary lesion immediately before and after delivery of 20Gy of conventionally fractionated radiotherapy. The MVD and the expression of TP was assessed with immunohistochemistry.

RESULTS

The irradiated samples were composed of cancer cell islets or bands, immersed within avascular degenerated tissue. In tumours that did not reach complete response after the end of radiotherapy, these viable cancer tissue areas had a significantly higher MVD (p=0.006) and increased percentage of cancer cells with nuclear TP expression (p=0.0004) than the MVD and the TP expression noted in specimens before radiotherapy. TP expression in these islets was directly related to the MVD (p=0.004, r=0.56).

CONCLUSION

The present study supports the idea that intensified angiogenic growth (angiogenic regeneration) during radiotherapy is associated with failure of radiotherapy.

The role of 99m Tc-sestamibi scintimammography and colour Doppler ultrasonography in the evaluation of breast lesions

In the present study we evaluated comparatively the diagnostic value of mammography, of 99mTc-sestamibi scintimammography (sestamibi-SC) and of colour Doppler ultrasonography (CD-US) in 116 breast lesions. Diagnosis was based on histopathological examination. Overall, out of 86 malignant tumours, 80 (93%) and 75 (87%) had a positive sestamibi-SC and positive CD-US, respectively. Out of 30 benign lesions, 25 (83%) and 26 (87%) had a negative sestamibi-SC and negative CD-US respectively. The true positive results were similar in palpable and in non-palpable lesions for both methods. Out of 19 non-palpable malignant tumours, mammography confirmed malignancy in only one case (5%), which was significantly lower than the results obtained by sestamibi-SC (89%; Px0.0001) and by CD-US (74%; P=0.0001). In palpable malignant tumours, by using mamography, true positive results were obtained in 54/67 (80.5%) patients, which was significantly lower than the results obtained by sestamibi-SC (94%; P=0.03) and marginally different to the results obtained by CD-US (91%; P=0.13). It is concluded that sestamibi-SC and CD-US are useful tools in clarifying the nature of breast lesions in cases with doubtful mammography. The clinical value of these diagnostic procedures in guiding subsequent therapeutic interventions requires further investigation.

Expression of hypoxia-inducible carbonic anhydrase-9 relates to angiogenic pathways and independently to poor outcome in non-small cell lung cancer

Carbonic anhydrase-9 (CA9), a transmembrane enzyme with an extracellular active site, is involved in the reversible metabolism of the carbon dioxide to carbonic acid. Up-regulation of CA by hypoxia and the hypoxia-inducible factor (HIF) pathway has been recently postulated (Wykoff et al. Cancer Res., 60: 7075-7083, 2000). In the present study we examined the expression of this enzyme in non-small cell lung cancer. Of 107 cases analyzed, 39 (36.4%) had strong membrane/cytoplasmic expression of CA9 and were grouped as positive. The staining was confined around areas of necrosis, and a significant association of CA9 expression with the extent of necrosis was noted (P = 0.004). Nevertheless, 38 of 74 cases with focal or extensive necrosis did not express CA9. CA9 expression was more frequent in the squamous cell histology (P = 0.001) and with advanced T stage (P = 0.009). A significant coexpression of CA9 with platelet-derived endothelial cell growth factor and basic fibroblast growth factor receptor expression was noted. Double staining of CA9 with anti-CD31 monoclonal antibody revealed an overall higher microvessel density in the areas expressing CA9 than in negative areas (P = 0.0005). Thirty-one of 38 CA9-positive cases were positive for HIF1a/HIF2a, but HIF positivity was a more common event (68 of 107) and their patterns of expression were diffuse (not confined in the necrotic areas). A direct association of CA9 expression with epidermal growth factor receptor, c-erbB-2, and MUC1 expression was also noted (P < 0.04). Survival analysis showed that CA9 expression is related to poor prognosis. CA9 expression in tumors with low vascularization defined a prognosis similar to the one of patients with highly angiogenic tumors. Multivariate analysis revealed that CA9 expression is a significant prognostic factor independent of angiogenesis. We conclude that CA9 is an important molecule in non-small cell lung cancer, the up-regulation of which occurs in highly hypoxic/necrotic regions of the tumors. The expression of CA9 is linked to the expression of a constellation of proteins involved in angiogenesis, apoptosis inhibition, and cell-cell adhesion disruption, which explains the strong association of CA9 with poor outcome.

Hypoxia-regulated carbonic anhydrase-9 (CA9) relates to poor vascularization and resistance of squamous cell head and neck cancer to chemoradiotherapy

PURPOSE

Carbonic anhydrases are proteins involved in the catalytic hydration of carbon dioxide to carbonic acid. Recent studies show that carbonic anhydrase 9 (CA9) is up-regulated by hypoxia and that its immunohistochemical tissue distribution follows the distribution of the radiosensitizer pimonidazole (C. C. Wykoff et al., Cancer Res. 60: 7075-7083, 2001). Therefore, CA9 expression may show hypoxia levels of clinical importance.

EXPERIMENTAL DESIGN

We assessed the expression of CA9 and the microvessel density (MVD; CD31-positive) in 75 locally advanced squamous cell head and neck cancers treated with concurrent chemoradiotherapy with carboplatin.

RESULTS

Strong membrane/cytoplasmic CA9 expression, noted in 20/75 (26.6%) tumors, mainly occurred in tumors with very poor vascularization (expression in 63% versus 14%; P < 0.0001), was located around areas of focal necrosis, and was related to poor complete response rate (40% versus 70%; P = 0.02). These observations suggested that CA9 might be a marker of clinically important hypoxia. Combining the CA9 staining and the tumor angiogenicity (MVD), we identified three groups of patients: (a) hypoxic tumors; (b) euoxic highly angiogenic tumors; and (c) euoxic non-highly angiogenic tumors. Groups (a) and (b) had a very poor local relapse-free survival (P < 0.0001).

CONCLUSIONS

Stratification of patients undergoing radical radiotherapy using the CA9/MVD model may be useful for the individualization of therapeutic strategies combining antiangiogenesis and hypoxia targeting with radiotherapy.

Tumour angiogenesis and response to radiotherapy

The important role of angiogenesis as a predictive factor of response to cytotoxic and radiation therapy has been recently raised. Poor tumour oxygenation is a well recognised feature related to radio-resistance. Since the vascular density is linked to the availability of oxygen and drugs to the tumoural stroma, poor density should be a potent marker of reduced blood perfusion and, therefore, hypoxia and low drug intratumoural concentration. On the other hand, high vascular density and angiogenic ability of cancer is not synonymous with high blood flow since the geometry of the vascular/epithelial component distribution, vascular collapse due to increased interstitial blood pressure, or non-functional vasculature due to an immature structure of the vessels may not allow the establishment of an adequate blood flow, which results in tissue hypoxia. Moreover, activation of angiogenic pathways confer a cancer cell proliferation/apoptosis advantage and trigger an angiogenic regeneration process during fractionated radiotherapy or between the courses of chemotherapy, resulting in rapid tumour re-growth and failure of radiotherapy due to reasons independent of hypoxia and blood flow. The present study reviews the literature on angiogenesis and radiotherapy and suggests a classification of tumours according to their angiogenic ability, which could become a useful tool for the identification of sub-groups of patients that could benefit from specific radiotherapy schedules or combination regimens with cytotoxic and anti-angiogenic compounds.

Relation of hypoxia inducible factor 1 alpha and 2 alpha in operable non-small cell lung cancer to angiogenic/molecular profile of tumours and survival

Hypoxia inducible factors HIF1alpha and HIF2alpha are important proteins involved in the regulation of the transcription of a variety of genes related to erythropoiesis, glycolysis and angiogenesis. Hypoxic stimulation results in rapid increase of the HIF1alpha and 2alpha protein levels, as a consequence of a redox-sensitive stabilization. The HIFalphas enter the nucleus, heterodimerize with the HIF1beta protein, and bind to DNA at the hypoxia response elements (HREs) of target genes. In this study we evaluated the immunohistochemical expression of these proteins in 108 tissue samples from non-small-cell lung cancer (NSCLC) and in normal lung tissues. Both proteins showed a mixed cytoplasmic/nuclear pattern of expression in cancer cells, tumoural vessels and tumour-infiltrating macrophages, as well as in areas of metaplasia, while normal lung components showed negative or very weak cytoplasmic staining. Positive HIF1alpha and HIF2alpha expression was noted in 68/108 (62%) and in 54/108 (50%) of cases respectively. Correlation analysis of HIF2alpha expression with HIF1alpha expression showed a significant association (P< 0.0001, r = 0.44). A strong association of the expression of both proteins with the angiogenic factors VEGF (P< 0.004), PD-ECGF (P< 0.003) and bFGF (P< 0.04) was noted. HIF1alpha correlated with the expression of bek-bFGF receptor expression (P = 0.01), while HIF2alpha was associated with intense VEGF/KDR-activated vascularization (P = 0.002). HIF2alpha protein was less frequently expressed in cases with a medium microvessel density (MVD); a high rate of expression was noted in cases with both low and high MVD (P = 0.006). Analysis of overall survival showed that HIF2alpha expression was related to poor outcome (P = 0.008), even in the group of patients with low MVD (P = 0.009). HIF1alpha expression was marginally associated with poor prognosis (P = 0.08). In multivariate analysis HIF2alpha expression was an independent prognostic indicator (P = 0.006, t-ratio 2.7). We conclude that HIF1alpha and HIF2alpha overexpression is a common event in NSCLC, which is related to the up-regulation of various angiogenic factors and with poor prognosis. Targeting the HIF pathway may prove of importance in the treatment of NSCLC.

Tumor specific activation of the VEGF/KDR angiogenic pathway in a subset of locally advanced squamous cell head and neck carcinomas

Vascular endothelial growth factor (VEGF) and its receptors, Flt-1 and flk-1(KDR), constitute an important angiogenic pathway which, under hypoxic conditions, is up-regulated in many solid tumours. We used the monoclonal antibody 11B5, specific for recognizing VEGF expression and the 'VEGF/flk-1(KDR) complex' on tumour endothelium, to assess free VEGF protein expression and VEGF/receptor activated microvessel density (aMVD) in a series of 104 inoperable locally advanced squamous cell carcinomas of the head and neck, treated with chemo-radiotherapy. High VEGF expression in cancer cells was strongly associated with high VEGF/receptor expression in the vasculature. The high VEGF expression and the aMVD were not associated with the standard microvessel density (sMVD), as assessed with the monoclonal antibody anti-CD31 and, were not detected in normal tissue. An increased sMVD, however, was significantly related with the expression thymidine phosphorylase (TP), and also with the nuclear accumulation of the oncoprotein p53, but neither p53 nor TP was associated with VEGF expression by cancer cells or VEGF/receptor complex aMVD. In 35% of cancer cases examined, more than 20% of the microvessels assessed with anti-CD31 also expressed the VEGF/KDR complex. The vasculature of the normal head and neck mucosa did not express the VEGF/KDR complex. There was no association between VEGF expression or VEGF/receptor complex aMVD and response to chemo-radiotherapy or patient's survival. It is concluded that activation of the angiogenic pathway VEGF/flk-1(KDR) is tumor specific in a subgroup of locally advanced squamous cell carcinomas of the head and neck. Selective destruction of this type of vasculature, using immunoconjugates directed against the VEGF/receptor complex, may prove therapeutically useful for patients with a high tumoral VEGF/flk-1(KDR) activated microvessel fraction.

High dose daily amifostine and hypofractionated intensively accelerated radiotherapy for locally advanced breast cancer. A phase I/II study and report on early and late sequellae

Intrinsic radioresistance, tumor hypoxia and ability of cancer cells to undergo rapid repopulation during radiotherapy are associated with failure of radiotherapy. Tumors with low alpha/beta-ratio values or hypoxic tumors unable to undergo re-oxygenation, are unlikely to be eradicated with standard radiotherapy. Although the therapeutic efficacy of accelerated regimens based on low-dose per fraction may be high since they minimize the adverse role of rapid tumor repopulation, the cellular compartment with low alpha/beta-ratio values (i.e. hypoxic cells) remains a limiting factor. Accelerated hypofractionation, which may be more effective in such tumors, cannot be safely applied unless normal tissues are protected. In the present study we assessed the feasibility of hypofractionated and accelerated radiotherapy supported by cytoprotection (HypoARC) with high dose daily amifostine. Fifteen breast cancer patients with locally advanced disease entered radiation-dose escalation protocoL Twelve consecutive fractions of 3.5-4Gy (5 fractions/week) were given to the breast/chest wall, supraclavicular and axillary area, within 17 days. A high dose of amifostine, at 1,000 mg flat dose, was given 20 minutes before each radiotherapy fraction. Amifostine administration was well- tolerated with minor side-effects (vomiting in 6 out of 15 and hypotention in 2 out of 15 patients). Radiation induced acute skin toxicity was negligible (grade 3 in 1 out of 15 patients). Ten out of 15 patients survived more than 12 months and 7 out of 15 more than 18 months following HypoARC. None of these patients showed any signs of late sequellae, such as lung and myoskeletal fibrosis, or brachial plexopathy. Complete and partial responses were obtained in 11 out of 15 (73%) and in 4 out of 15 (27%) patients, respectively. High dose daily amifostine during hypofractionated radiotherapy is feasible. HypoARC regimen is well-tolerated, effective and has minimal acute and late toxicity to normal breast, chest and axillary tissues.

Tumor angiogenesis is associated with MUC1 overexpression and loss of prostate-specific antigen expression in prostate cancer

The biological potential of prostate cancer is highly variable and cannot be satisfactorily predicted by histopathological criteria alone. Therefore, additional and more precise information is desirable. Although angiogenesis has been suggested as being of prognostic importance in many human cancers, and MUC1, also known as episialin, was thought to be responsible for the development of metastasis, the role of these parameters in prostate cancer remains unclear. The aim of this study was to investigate whether angiogenesis, assessed as microvessel density (MVD), was correlated with the expression of prostate tumor MUC1 and prostate-specific antigen (PSA) or with histopathological grade at diagnosis, and to determine whether any of these factors might provide additional information with regard to prostate tumor biology. Paraffin-embedded material from 60 patients with prostate carcinoma was examined immunohistochemically, using the monoclonal antibody CD31 to determine MVD, and the monoclonal antibodies CCE831 and ER-PR8 to assess MUC1 and PSA expression, respectively. The tumors were categorized according to the Gleason grading system. MUC1 overexpression was significantly related to a high intratumoral angiogenesis (P = 0.02). By contrast, a high PSA expression by prostate cancer cells was associated with low MVD (P = 0.03). No correlation was found between MUC1 and PSA expression. Usually, high-grade tumors were not PSA-expressive and tended to display increased angiogenesis. These differences, however, were not of statistical significance. Similarly, there was no statistically significant association between histological grade and MUC1 expression or angiogenesis. It is suggested that PSA may have a direct suppressive effect on new blood vessel formation in prostate cancer, whereas the expression of MUC1 in this tumor may be connected with an angiogenic phenotype. Additional studies are obviously needed to clarify the precise role of these proteins in prostate cancer.

Angiogenesis and apoptosis-related protein (p53, bcl-2, and bax) expression versus response of gastric adenocarcinomas to paclitaxel and carboplatin chemotherapy

The role of angiogenesis and apoptosis-related proteins in defining response to chemotherapy is poorly understood. We examined the microvessel density (MVD) and the expression of p53, bcl-2, and bax proteins in a series of 28 locally advanced gastric adenocarcinomas, treated with paclitaxel and carboplatin. A strong cytoplasmic reactivity in more than 10% of cancer cells was recorded in 25% of cases for p53 protein, and in 14% and 64% of cases for bcl-2 and bax proteins, respectively. Microvessel density was assigned in three categories: low (<35), medium (35-60), and high (>60). Tumors of medium MVD showed a significantly higher response rate compared with those of high or low MVD (p = 0.01 and 0.001, respectively), and prognosis was significantly better in this group of patients with medium MVD tumors (p < 0.02). Loss of bax protein expression was somewhat more frequent in tumors resistant to chemotherapy, but this difference was not of statistical significance. Nuclear p53 reactivity was associated with higher MVD (p = 0.02). The expression of p53 and bcl-2 did not influence the outcome of treatment. The present study suggests that although apoptosis-related proteins may have a role in defining response to taxanes, parameters related to tumors' vasculature, such as drug availability or angiogenic tissue regeneration, may be equally important.

Nuclear expression of human apurinic/apyrimidinic endonuclease (HAP1/Ref-1) in head-and-neck cancer is associated with resistance to chemoradiotherapy and poor outcome

PURPOSE

HAP1/Ref-1 endonuclease is involved in the repair of DNA strand breaks and in the activation of DNA binding of several transcription factors. HAP1 is also a potent activator of wild type p53. It therefore has multiple possible roles in the response of human cancer to radiotherapy and chemotherapy.

METHODS AND MATERIALS

The nuclear expression of HAP1 and p53 proteins was studied by immunohistochemistry in paraffin-embedded material from 95 patients with locally advanced squamous cell head-and-neck cancer (HNC) treated with radical radiotherapy (38 cases with induction platinum-based chemotherapy and 57 with concurrent platinum chemoradiotherapy).

RESULTS

HAP1 was present in the nuclei of normal epithelium and stromal cells. Loss of HAP1 nuclear expression was frequently noted in cancer cells. Tumors with high HAP1 nuclear expression (% of positive cells > mean; mean = 11%) were of good differentiation (p = 0.06) and presented frequently with advanced nodal disease (p = 0.01). High nuclear HAP1 expression was significantly associated with poor complete response rate (p = 0.00001), shorter local relapse-free interval (p < 0.0001), and poorer survival (p < 0.0008). HAP1 nuclear reactivity was inversely associated with p53 nuclear accumulation (p = 0.003). The inverse correlation between HAP1 expression and prognosis was independent of p53 status.

CONCLUSION

HAP1 nuclear expression in HNC is inversely associated with p53 nuclear accumulation and directly related to resistance to chemoradiotherapy and poor survival. Further clinical investigation is required to confirm these findings.

The angiogenic pathway "vascular endothelial growth factor/flk-1(KDR)-receptor" in rheumatoid arthritis and osteoarthritis

Active angiogenesis, together with an up-regulation of angiogenic factors, is evident in the synovium of both rheumatoid arthritis (RA) and osteoarthritis (OA). The present study assessed, by immunohistochemistry, the microvessel density in the synovium of these arthritides and in normal controls, in relation to the expression of the angiogenic factors vascular endothelial growth factor (VEGF) and platelet-derived endothelial cell growth factor (PD-ECGF) and the apoptosis-related proteins bcl-2 and p53. More importantly, using the novel 11B5 MAb, the activated "VEGF/flk-1(KDR)-receptor" microvessel density was assessed. VEGF expression in fibroblasts was diffuse in both RA and OA. Diffuse PD-ECGF expression of fibroblasts was noted in all cases of RA, while fibroblast reactivity was focal in the OA material. The standard microvessel density (sMVD), as assessed with the anti-CD31 monoclonal antibody (MAb), was higher in RA (64+/-12) and in OA (65+/-16) than in normal tissues (52+/-8; p=0.008 and 0.0004, respectively). The activated microvessel density (aMVD), assessed with the 11B5 MAb, was significantly higher in RA (29+/-10) than in OA (17+/-4; p<0.0001) and than in normal tissues (14+/-2; p<0.0001). The "activation ratio" (aMVD/sMVD) was statistically higher in RA (0.46+/-0.17) than in OA and normal synovial tissues, the latter two having a similar ratio (0.28+/-0.08 and 0.26+/-0.03, respectively). Cytoplasmic bcl-2 expression was frequent in the synovial cells of OA, but rare in RA. Nuclear p53 protein accumulation was never observed. It is suggested that the angiogenic pathway VEGF/flk-1(KDR) may play an important role in the pathogenesis of RA and OA. Thus, failure of VEGF/flk-1(KDR) activation, in the presence of increased VEGF expression, may indicate a synovium with an impaired capacity to establish a viable vasculature, consistent with the degenerative nature of OA. On the other hand, the activated angiogenesis in RA shows a functional, still pathologically up-regulated VEGF/flk-1(KDR) pathway. Whether restoration of an impaired VEGF/flk-1(KDR) pathway in OA, or inhibition of this in RA, would prove of therapeutic importance requires further investigation.

Angiogenic interactions of vascular endothelial growth factor, of thymidine phosphorylase, and of p53 protein expression in locally advanced gastric cancer

The assessment of the angiogenic profile of tumors may become an important tool as a guide for the inclusion of novel drugs and molecular therapies into the standard chemoradiotherapy policy. Several studies have shown the prognostic importance of microvessel density (MVD) and of angiogenic factor expression in operable gastric cancer. In the present study we investigated, with immunohistochemistry the MVD, the expression of vascular endothelial growth factor (VEGF) and of thymidine phosphorylase (TP) expression, as well as the nuclear expression of p53 protein, in a series of patients with locally advanced inoperable gastric cancer. A strong association of VEGF with TP expression was noted (P = 0.005), and tumors coexpressing these factors had a statistically higher MVD (P = 0.0001). Nuclear p53 accumulation was also related to a high MVD (P = 0.004), and this was independent of VEGF or TP expression. Microvessel density showed a bell-shaped association with prognosis; cases with an intermediate MVD exhibit a favorable outcome (P < 0.05). A trend of nuclear TP expression to define a group of patients with poorer prognosis was noted (P = 0.06), while none of the remaining variables showed any significant association. The immunostaining results allowed the grouping of the angiogenic profile in four major categories: 1) highly vascularized tumors with VEGF and/or TP expression (about 36% of cases); 2) highly angiogenic tumors with p53 nuclear accumulation and low VEGF/TP expression (7% of cases); 3) poorly vascularized tumor with low VEGF/TP and negative nuclear p53 staining (32% of cases); 4) poorly vascularized tumors with TP expression (7% of cases). Specific therapies targeting hypoxia, VEGF, or TP expression as well as p53 gene therapy have entered clinical experimentation or are already available for clinical use. Using the suggested markers more than 80% of locally advanced gastric carcinomas can be grouped in different categories according to their angiogenic profile. Such a categorization may be useful for phase III trials on novel therapies targeting the major angiogenesis-related features studied here.

Hypoxia inducible factor (HIF-1a and HIF-2a) expression in early esophageal cancer and response to photodynamic therapy and radiotherapy

Hypoxia inducible factor 1a and 2a (HIF-1a and HIF-2a) are key proteins regulating cellular response to hypoxia. Because the efficacy of photodynamic therapy (PDT) is dependent on the presence of oxygen, the assessment of HIF-1a and HIF-2a expression may be of value in predicting clinical response to PDT. Using recently produced MoAbs, we examined the expression of HIF1a and HIF2a in a series of 37 early-stage esophageal cancers treated with PDT and with additional radiotherapy in case of incomplete response after PDT. Strong expression of the HIF1a and of HIF2a proteins in all optical fields examined was noted in 51% and in 13% of cases, respectively. High expression was associated with a low complete response (CR) rate and with the absence of bcl-2 protein expression. On the contrary, bcl-2 expression was associated with a high CR rate. Combined analysis of HIF1a and bcl-2 protein expression revealed that of 16 cases with high HIF1a expression and the absence of bcl-2 reactivity, only 1 (7%) responded completely to PDT (P = 0.007). Bivariate analysis showed that HIF1a expression was independently related to response to PDT (P = 0.04; t ratio = 2.8), whereas bcl-2 approached significance (P = 0.07; t-ratio = 1.8). The final response to radiotherapy was high (70%) and independent of the HIF and bcl-2 status, which may be a result of reoxygenation after cellular depletion mediated by PDT. The present study suggests that assessment of HIF and of bcl-2 expression are important predictors of in vivo sensitivity to PDT. Modulation of PDT response with bioreductive drugs and/or drugs targeting bcl-2 (i.e., taxanes) may prove of significant therapeutic importance in a subgroup of patients with high HIF expression.

Mean platelet volume: a useful marker of inflammatory bowel disease activity

OBJECTIVES

We investigated whether the mean platelet volume would be a useful marker in the evaluation of inflammatory bowel disease activity.

METHODS

Complete blood count, C-reactive protein, erythrocyte sedimentation rate, serum thrombopoietin and erythropoietin, plasma beta-thromboglobulin, and platelet factor 4 were measured in 93 patients with ulcerative colitis, 66 patients with Crohn's disease, and 38 healthy blood donors. Disease activity was assessed by the Clinical Colitis Activity Index in patients with ulcerative colitis and by the Crohn's Disease Activity Index in patients with Crohn's disease.

RESULTS

Mean platelet count was increased in patients with active compared to inactive ulcerative colitis (p < 0.05), and in patients with active compared to inactive Crohn's disease (p = 0.0002) or healthy controls (p < 0.0001). On the other hand, mean platelet volume was significantly decreased in patients with active compared to inactive ulcerative colitis (p = 0.02) or healthy controls (p < 0.0001), and in patients with active compared to inactive Crohn's disease (p = 0.0005) or healthy controls (p < 0.0001). Mean platelet volume was inversely correlated with the white blood cell count (r = -0.17, p = 0.02), C-reactive protein (r = -0.46, p = 0.009) and erythrocyte sedimentation rate (r = -0.28, p = 0.008). No significant correlations were found between mean platelet volume and serum thrombopoietin or erythropoietin levels; however, a strong negative correlation between mean platelet volume and beta-thromboglobulin (r = -0.34, p < 0.0001) and platelet factor 4 (r = -0.30, p = 0.0002) was observed.

CONCLUSIONS

Mean platelet volume is significantly reduced in active inflammatory bowel disease and is negatively correlated with the known inflammatory bowel disease activity markers and the platelet activation products. We propose that mean platelet volume provides a useful marker of activity in inflammatory bowel disease.

Clinical and experimental evidence of Bcl-2 involvement in the response to photodynamic therapy

PURPOSE

The role of apoptosis related proteins in the response of human malignancies to photodynamic therapy (PDT) is under investigation. The aim of the study was to examine the role of p53 and of bcl-2 protein expression in the response to PDT.

MATERIALS AND METHODS

Paraffin-embedded material from 37 patients with early esophageal cancer treated with PDT (argon dye laser after intravenous injection of hematoporphyrine derivative) was studied immunohistochemically for p53 protein nuclear accumulation and bcl-2 cytoplasmic expression. Patients with residual disease after two rounds of PDT received definitive radiotherapy. In a subsequent in vitro study, W138 human lung fibroblasts and W138-SV-40 virus transformed were assessed for their sensitivity to PDT. The constitutive bcl-2 overexpression of the transformed cells vs. normal cells (assessed with RT-PCR) was 16-fold.

RESULTS

Positive bcl-2 and p53 expression was noted in 10 out of 36 (27%) and 14 out of 36 (39%) patients, respectively. Seven out of 11 tumors (63%) with bcl-2 expression responded completely to PDT vs. 6 out of 26 (23%) of cases with no bcl-2 expression (p = 0.02). No association of p53, T-stage and of histology grade with response to PDT or PDT/RT was noted. The sensitivity to PDT of transformed human fibroblasts compared to normal ones was 4 times more at a fluence of 4.3 J/cm2 (4% vs. 1% cell kill) as well as at a fluence of 5.4 J/cm2 (8% vs. 2% cell kill).

CONCLUSION

Bcl-2 protein expression is associated with favorable response to PDT and can be used as a predictor of cancer response to PDT. This finding can be explained by experimental studies showing that PDT induces selective degradation of the bcl-2 protein, leading to apoptosis by decreasing the bcl-2/bax ratio. Studies on PDT combination with agents targeting bcl-2 (i.e. taxanes) are on going to eventually assess a super-additive effect.

Bax protein expression in colorectal cancer: association with p53, bcl-2 and patterns of relapse

This study evaluated the frequency and the prognostic significance of bax, bcl-2 and p53 proteins in stage B and C adenocarcinomas of the colon and rectum. Paraffin-embedded specimens from 268 patients with colorectal adenocarcinomas, treated with surgery, were assessed; of these 160 cases were Duke's stage B and 108 cases were Duke's stage C disease. Adjuvant chemotherapy was given to all stage C and to 108 out of 160 stage B cancer patients, while those having rectal malignancy also received pelvic radiotherapy. Duke's stage B patients were treated either with surgery alone or with surgery and radiotherapy. The follow-up period at the time of analysis ranged from 12-72 months (median 32 months). Immunohistochemical expression of bax, bcl-2 and mutant p53 proteins was detected with a frequency of 42%, 37% and 48%, respectively. However, the expression was strong only in 17% of tumours, on average. A strong bcl-2 expression was significantly associated with a strong bax expression (p < 0.0001) and with absence of p53 nuclear accumulation (p < 0.005). There was, however, no correlation between bax and p53 proteins. Furthermore, bcl-2 expression was significantly more frequent in grade I and 2 adenocarcinomas compared to grade 3 disease (p = 0.01). In stage B (but not C) adenocarcinomas, bax expression was directly associated with higher risk of local relapse (p = 0.04). By contrast, cases with p53 nuclear accumulation, when they had received adjuvant radiotherapy, were significantly associated with a lower incidence of local relapse (p = 0.01), but a higher rate of distant metastasis (p = 0.06). Multivariate analysis for disease free and overall survival showed that bax expression and high Duke's stage were independent prognostic parameters associated with an unfavourable outcome (p = 0.009 and p = 0.0001, respectively). It was concluded that the immunohistochemical expression of bax is a marker of poor prognosis and of a higher risk of local relapse in patients with colorectal adenocarcinomas. p53 nuclear accumulation is associated with a better local control, following radiotherapy and with a metastatic phenotype. The development of novel monoclonal antibodies recognising specifically the mutated versus the wild type form of proteins would apparently improve the prognostic and predictive value of the immunohistochemically detected apoptotic proteins.

'Invading edge vs. inner' (edvin) patterns of vascularization: an interplay between angiogenic and vascular survival factors defines the clinical behaviour of non-small cell lung cancer

Neo-angiogenesis during neoplastic growth involves endothelial mitogenic and migration stimuli produced by cancer or tumour stromal cells. Although this active angiogenesis takes place in the tumour periphery, the process of vessel growth and survival in inner areas and its clinical role remain largely unexplored. The present study compared the microvessel score (MS) as well as the single endothelial cell score (ECS) in the invading edge and in inner areas of non-small cell lung carcinomas (NSCLCs). Three different patterns of vascular growth were distinguished: the edvin (edge vs. inner) type 1, where a low MS was observed in both peripheral and inner tumour areas; the edvin type 2, where a high MS was noted in the invading front but a low MS in inner areas; and the edvin type 3, where both peripheral and inner tumour areas had a high MS. The ECS was high in the invading edge in edvin type 2 and 3 cases and was sharply decreased in both types in inner areas, suggesting that endothelial cell migration is unlikely to contribute to the angiogenic process in areas away from the tumour front. Expression of the vascular endothelial growth factor (VEGF) and of thymidine phosphorylase (TP) was associated with a high MS in the invading edge. VEGF was associated with a high MS in inner areas (edvin 3), while TP expression was associated with edvin type 2, showing that VEGF (and not TP) contributes to the preservation of the inner vasculature. Both edvin type 2 and 3 cases showed an increased incidence of node metastasis, but edvin type 3 cases had a poorer prognosis, even in the N1-stage group. The present study suggests that tumour factors regulating angiogenesis and vascular survival are not identical. A possible method is reported to quantify these two parameters by comparing the MS in the invading edge and inner areas (edvin types). This observation may contribute to the evaluation of the effectiveness of different therapeutic approaches, namely vascular targeting vs. anti-angiogenesis.

Elevated thrombopoietin serum levels in patients with inflammatory bowel disease

OBJECTIVES

Elevated platelet count is a well recognized marker of inflammatory bowel disease (IBD) activity. Thrombopoietin (TPO) is a critical cytokine in the physiological regulation of thrombopoiesis. The aim of this study was to investigate the serum levels of endogenous TPO in patients with IBD, the relationship between platelet counts and TPO levels, and the correlation of TPO with the clinical characteristics of the patients.

METHODS

TPO levels in 40 patients with Crohn's disease (CD), 63 patients with ulcerative colitis (UC), and in 42 healthy blood donors were assessed by ELISA. Platelet and white blood cell counts as well as C-reactive protein, and erythrocyte sedimentation rate were measured.

RESULTS

TPO levels were significantly elevated in patients with CD (mean 124.3 +/- SD 58.0 pg/ml, p < 0.0001) and in patients with UC (mean 152.2 +/- SD 142.3 pg/ml, p < 0.0001), compared to controls (mean 53.4 +/- SD 45.7 pg/ml). TPO levels remained significantly elevated in remission (mean 144.7 +/- SD 131.1 pg/ml, p < 0.0001 compared to controls). Platelets were significantly elevated only in active CD, being normal in inactive disease as well as in all patients with UC. There was no significant correlation between TPO levels and various clinical characteristics of patients with IBD. No significant correlation was found between TPO levels and either platelet counts or white blood cell counts, erythrocyte sedimentation rate, and C-reactive protein.

CONCLUSIONS

TPO levels are increased in IBD, irrespective of disease activity, platelet counts, and clinical characteristics of the patients. These observations indicate that TPO, apart from being a platelet producer, might have additional functions, probably related to the procoagulant state of IBD.

High intratumoural accumulation of stealth liposomal doxorubicin (Caelyx) in glioblastomas and in metastatic brain tumours

The blood-brain barrier is a major obstacle for the chemotherapeutic drugs to effectively reach primary or secondary brain tumours. Stealth liposomal drugs are highly accumulated in tumoural tissues. In the present study we investigated the relative accumulation of(99m)Tc-DTPA radiolabelled stealth liposomal doxorubicin (Caelyx) in 10 patients with metastatic brain tumours and five patients with brain glioblastoma undergoing radiotherapy. Patients with metastatic brain lesions were treated with 10 consecutive fractions of radiotherapy (whole brain, 3 Gy/fraction, day 1-12) followed by a booster dose of 9 Gy (3 Gy/fraction, day 21-23). Caelyx, at a dose of 25 mg mg(-2)was given on day 1 and on day 21. Radiolabelled Caelyx accumulation was 13-19 times higher in the glioblastomas and 7-13 times higher in the metastatic lesions, as compared to the normal brain. The drug accumulation in the tumoural areas was 40-60% of the accumulation in the bone marrow of the skull bones. The normal brain radioactivity was <4% of the bone marrow, confirming an important shielding effect of the blood-brain barrier in the normal but not in the tumoural tissue. Four of 10 patients with metastatic lesions showed a complete response in CT-scan performed 2 months following therapy. There was no severe toxicity related to radiotherapy or to chemotherapy noted. It is concluded that stealth liposomal drugs selectively overcome the blood-brain barrier in the tumoural areas. The clinical importance of this observation is now under investigation.