Endocrinological Study of the Dopaminergic Regulation of Prolactin Release in Metastatic Breast Cancer

Aims and Background

Prolactin (PRL) may be a growth factor for breast cancer. Abnormally high levels of PRL have been proven to be associated with a poor prognosis in metastatic breast cancer. However, most studies have been limited to the evaluation of basal levels of PRL rather than its response to the classical endocrine dynamic tests. This study was performed to analyse the dynamic secretion of PRL under stimulatory and inhibitory tests in metastatic breast cancer.

Methods

The study included 10 untreated metastatic breast cancer women, who were evaluated after the classical stimulatory and inhibitory tests for PRL secretion with the antidopaminergic agent Metoclopramide (10 mg iv as a bolus) and with L-dopa, respectively. Serum levels of PRL were measured by RIA before and at subsequent intervals after drug administration. PRL levels were considered to be elevated when they were higher than 25 ng/ml.

Results

Abnormally high basal levels of PRL were seen in 6/10 patients. L-dopa was unable to inhibit PRL secretion, whose mean concentrations paradoxically significantly increased in response to L-dopa, with values comparable to those observed after the classical stimulatory test with metoclopramide.

Conclusions

This study confirm the existence of hyperprolactinemia associated with metastatic breast cancer. In addition, by showing a paradoxical rise of PRL in response to L-dopa, which inhibits PRL secretion in physiological conditions, this study would suggest that breast cancer-related hyperprolactinemia may depend at least in part on endogenous disease-related neuroendocrine alterations.

Endocrine and Clinical Effects of an Lhrh Analogue in Pretreated Advanced Breast Cancer

Buserelin represents one of the main LHRH analogues. It appears to be effective in untreated metastatic breast cancer, whereas its activity in pretreated advanced patients remains to be established. To evaluate endocrine and clinical effects of buserelin in pretreated advanced mammary carcinoma, 14 postmenopausal women with metastatic breast cancer, which had been previously treated with hormones and/or chemotherapy, entered the study. Buserelin was subcutaneously injected at a daily dose of 1.5 mg for 7 days, then intranasally at a daily dose of 1.2 mg until progression. Before and after the 7 days of subcutaneous administration of the LHRH analogue, FSH, LH, estradiol, testosterone basal serum levels, and PRL response to TRH were examined. After the 7 days of buserelin subcutaneous injection, a significant decrease in FSH, LH and estradiol values was observed, whereas testosterone was not affected. PRL response to TRH did not change after buserelin subcutaneous treatment in 8 patients, it decreased in one and was completely abolished in the last 5 cases. All patients whose PRL response to TRH did not decrease had a progression within the first month of therapy, whereas only 1 of 6 patients whose PRL response to TRH was reduced or abolished following buserelin administration showed a progression. Among the other 5 cases, 2 minor responses and 3 stable diseases were achieved. These preliminary results suggest that buserelin has only a limited effectiveness in metastatic breast cancer patients who have been previously treated with hormones and/or chemotherapy, and that its activity in the control of tumor growth is associated with a reduction in PRL secretion.

Prolactin Response to Thyrotropin-Releasing Hormone in Early and Advanced Human Breast Cancer

While prolactin (PRL) has been shown to stimulate the development of mammary carcinoma in several animal species, its role in human breast cancer remains to be established. To further investigate PRL secretion in human breast cancer, its basal levels and response to thyrotropin-releasing hormone (TRH) were evaluated in 16 patients (6 with no metastases and 10 with metastatic locations). The control group consisted of 19 healthy women. High PRL basal concentrations were seen in 2 patients only; no significant differences were found between the other patients and the normal subjects. The PRL increase induced by TRH administration was significantly higher in patients than in controls. Finally a change in the hormonal secretion was found after chemotherapy in 3 of the 5 patients in whom PRL response to TRH was evaluated either before or 10-12 days after a cycle of intravenous CMF adjuvant chemotherapy. These results demonstrate the existence of an exaggerated response of PRL to TRH in patients with breast cancer, even in the presence of normal basal levels. Moreover, they would seem to suggest a possible influence of CMF on PRL response to TRH stimulation.

Correlation between Changes in Prolactin and Melatonin Serum Levels after Radical Mastectomy

Both prolactin (PRL) and melatonin (MLT) (the most important pineal hormone) have been shown to play a role in regulating breast cancer growth. The present study was carried out to investigate the relationship between PRL and MLT secretions in human breast cancer. Twenty-four women with breast cancer, at clinical stage T1-2 N0-2 M0, were evaluated before and after radical mastectomy. As controls, 14 women who underwent surgery for reasons other than neoplastic disease were included in the study. PRL and MLT serum levels were measured by RIA before and 15 days after surgery. There were no significant differences in mean PRL serum levels between patients and controls; mean MLT serum values were significantly higher in patients than in controls. In no control subject was PRL affected by surgery. In contrast, 13/24 breast cancer women showed high PRL levels after mastectomy; the PRL rise induced by surgery was significantly higher in patients without axillary node involvement. MLT was not affected by mastectomy in 13 patients, whereas it was enhanced in 5 women and decreased in the last 6 cases. No significant correlation was seen between PRL and MLT changes induced by mastectomy. The present study shows that radical mastectomy influences PRL and MLT secretions, however, its clinical significance remains to be established.

Correlation of Serum Interleukin-2 Levels, Soluble Interleukin-2 Receptors and T Lymphocyte Subsets in Cancer Patients

An interleukin-2 (IL-2) in vitro reduced production has been observed in most metastatic cancer patients. At present, however, there are no data on blood IL-2 levels in vivo, because of the too low sensitivity of previous biological and enzyme immunoassay methods. The recent development of a sensitive RIA method allowed us to start a preliminary investigation of IL-2 production in basal conditions in human solid tumors. The study included 42 cancer patients. Breast and lung cancer were the two commonest neoplasms. Serum levels of IL-2 and soluble IL-2 receptors (SIL-2R), and CD4/CD8 ratio were measured in each patient. The control group consisted of 58 healthy subjects. Mean serum levels of IL-2 were significantly lower in metastatic patients (n = 23) than in those without metastases (n = 19). Patients with low CD4/CD8 ratio (n = 16) had significantly lower mean values of IL-2 than those with normal ratio (n=26). Finally, mean IL-2 concentrations were significanty lower in patients with elevated levels of SIL-2R than in those with normal values. These results would suggest that metastatic dissemination is associated with a decreased IL-2 production in vivo, and that reduced IL-2 production is more frequent in patients with low CD4/CD8 ratio.

A Study of Thyroid Function in Cancer Cachexia

The mechanisms responsible for cancer cachexia have not yet been clarified. To further investigate the role played by the hypothalamic-pituitary-thyroid axis in cancer cachexia, we evaluated serum levels of T3, FT3, T4, FT4, TSH and TBG in a group of 26 cancer patients, 14 of whom showed cachexia, whereas the other 12 had a body weight within the normal range despite their advanced diseases. As controls, 58 healthy subjects and 11 patients with benign weight loss were included in the study. Low levels of both T3 and FT3 were observed in all patients with benign weight loss and in 9/12 advanced cancer patients who had no cancer cachexia. On the contrary, only 4/14 cachectic cancer patients presented decreased values of T3 and FT3. Moreover, the mean serum levels of T3 and FT3 in cachectic oncologic patients were significantly higher than those seen both in non-cachectic cancer patients and in patients with benign weight loss. Since T3 is the biologically active thyroid hormone, the lack of a decrease in its production might play a role in the pathogenesis of cancer cachexia.

Increased Level of Soluble Interleukin-2 Receptor in Advanced Solid Tumors: A Preliminary Study

Both activated normal and transformed lymphocytes produce not only cell-associated but also cell-free IL-2R. Evidence of high serum concentrations of IL-2R appears to serve as a tumor marker in patients with lymphomas On the contrary, the role of soluble IL-2R in solid neoplasms has still to be defined. This investigation was carried out to analyze soluble IL-2R production in human solid tumors. The study included 35 patients with solid tumors (12 without and 23 with metastases), 58 healthy subjects and 6 lymphoma patients. Among cancer patients, lung and breast carcinoma were the two most frequent neoplasms. In each subject or patient, serum levels of IL-2R were measured by using an enzyme immunoassay. Moreover, in 14/23 patients with metastatic solid tumors, lymphocyte subpopulations were also evaluated. Serum levels of IL-2R were significantly higher in the cancer patients than in the normal subjects. The patients with metastatic solid tumors showed significantly higher mean levels than those without metastases, and similar to those observed in the lymphoma patients. Finally, there was no correlation between serum levels of IL-2R and the T4/T8 ratio, which was reduced in 5/14 cancer patients. Further studies will be needed to establish if elevated concentrations of IL-2R in the serum can contribute to the immunoincompetence of patients with disseminated solid neoplasms.

A Study of the Pineal Hormone Melatonin as a Second Line Therapy in Metastatic Colorectal Cancer Resistant to Fluorouracil plus Folates

Since there is no effective second line chemotherapy in colorectal cancer resistant to fluorouracil, this study was carried out to evaluate the therapeutic activity of the pineal hormone melatonin, which has appeared to have antineoplastic activity in some experimental conditions, in patients with metastatic colorectal carcinoma who did not respond to fluorouracil. The study included 14 patients (8 men, 6 women; mean age 58 years). Melatonin was given intramuscularly at a daily dose of 20 mg at 3.00 p.m. for 2 months; after that, melatonin therapy was continued at 10 mg/day orally in responder patients, in those with stable disease and/or an evident improvement in PS. One patient had a minor response; 3 other patients had a stable disease, wehereas the other 10 cases progressed. An evident improvement in PS was seen in 5/14 (36 %) patients. These preliminary results show that melatonin does not have important antitumor activity in metastatic colorectal cancer patients resistant to fluorouracil. However, the pineal hormone could be usefully employed as supportive care to improve the quality of life in these patients for whom no standard treatment is yet available.

Melatonin Increase as Predictor for Tumor Objective Response to Chemotherapy in Advanced Cancer Patients

Clinical studies have demonstrated an altered pineal function in cancer patients. Owing to the documented antineoplastic activity of the pineal gland, these anomalies could have a prognostic significance. This study was carried out to monitor changes in blood levels of melatonin, the most important pineal hormone, in relation to the clinical response to chemotherapy in human neoplasms. The study included 42 cancer patients of both sexes (breast cancer, 10; lung cancer, 13; colon cancer, 11; soft tissue sarcoma, 4; testicular cancer, 1; Hodgkin's disease, 1; peritoneal mesothelioma, 2). Melatonin serum levels were measured by radioimmunoassay before and 28 days after each cycle of chemotherapy. The results showed that, irrespectively of the type of tumor and chemotherapeutic regimen, 12/16 patients (75%) whose melatonin markedly enhanced after chemotherapy had an objective regression. In contrast, 2/26 patients only (8%) whose melatonin did not enhance after chemotherapy had a clinical response. The percentage of objective responses was statistically significantly higher in patients with a chemotherapy-induced melatonin increase than in those with no melatonin increase (p < 0.001). This study seems to demonstrate that melatonin determination can be used as a predictor of the objective response to chemotherapy in cancer patients. Moreover, it suggests that the antineoplastic effect of cytotoxic drugs may require participation of the pineal gland.

Malignant Testicular Germ Cell Tumor in Father and Son: A Case Report

This is the eighteenth case of testicular tumor in a father and son reported in the literature. The father had a seminoma and the son an embryonal carcinoma. The trend favoring more malignant tumors occurring at younger ages in the sons is confirmed by this report.

The Pineal Gland and Breast Cancer: Serum Levels of Melatonin in Patients with Mammary Tumors and Their Relation to Clinical Characteristics

Several studies have suggested that the pineal gland hormone melatonin may influence the growth of breast cancer. The importance of melatonin blood concentrations in the clinical history of human breast cancer, however, has still to be defined. To further investigate this problem, we used a RIA method to assay serum levels of the pineal hormone in 74 untreated breast cancer patients, clinical stage T1–3 NO-2 MO, and in 46 age-matched healthy women as controls. Mean serum melatonin levels were significantly higher inpatients than in controls. Melatonin concentrations were highest in breast cancer patients with the best prognosis (i.e. estrogen receptor-positive/node-negative cases). Mean levels of melatonin were significantly higher in estrogen receptor-positive patients than in the negative ones. They were also higher in node-negative than in node-positive cases, and in progesterone receptor-positive patients than negative ones, but none of these differences was statistically significant. No difference was observed in relation to menopausal status and to tumor histotype. These results suggest that melatonin plays a role in the hormone-dependency of human breast cancer.

Interleukin-4 Blood Concentrations in Early and Metastatic Human Solid Neoplasms

Blood levels of the immunosuppressive cytokines IL-6 and IL-10 are often abnormally high in patients with advanced cancer. However, since IL-6 and IL-10 may be produced by macrophages and TH2 cells, the evidence of abnormally high values of IL-6 and/or IL-10 may reflect hyperactivation either of the macrophage system or of TH2 cell functions. In contrast, IL-4 is almost completely produced by the TH2 lymphocytes. Therefore, evaluation of IL-4 levels could help to differentiate macrophage from TH2 cell hyperactivation. This study was performed to investigate IL-4 serum levels in a group of cancer patients in relation to the stage of disease and to the secretion of other cytokines. The study included 50 patients, 28 of whom showed distant organ metastases. Lung cancer and gastrointestinal cancers were the most frequent neoplasms in our patients. The control group consisted of 60 healthy subjects. IL-4 was measured by the Elisa method. No patient showed high levels of IL-4. No significant differences were seen between controls and cancer patients, nor between metastatic and non-metastatic patients. In addition, no significant differences in IL-4 mean values were found between patients with normal or high levels of IL-6 and IL-10, or between patients with normal or low IL-2 concentrations. This preliminary study seems to exclude cancer-related abnormally high secretion of IL-4. Therefore, the high levels of IL-6 and/or IL-10 often occurring in advanced neoplastic disease would mainly depend on macrophage production.

Neuroimmunomodulation in Cancer Patients: Correlations between Melatonin and ß-Endorphin Blood Levels and T Helper/Suppressor Ratio

The pineal gland and opioid peptides play roles in the neuroendocrine control of immunity. Both neuroendocrine and immune dysfunctions have been observed in cancer but the importance of the altered secretion of neurohormones in the immunoincompetence of cancer patients has never been investigated. This study concomitantly evaluated neuroendocrine and immune functions in 40 patients with early or advanced neoplastic disease. In each patient, melatonin and β-endorphin blood levels and lymphocyte subtypes were determined on venous blood samples collected during the morning. Metastatic patients had lower melatonin levels and a lower T4/T8 ratio than patients without metastases but no significant correlation was found between melatonin and the T4/T8 ratio. β-endorphin levels appeared to be normal in all patients. These results suggest that melatonin and β-endorphin secretion have no role in determining immune dysfunctions in cancer.

Increased Blood Concentrations of Interleukin-12 are Associated with a Longer Survival in Untreatable Metastatic Solid Tumor Patients: Preliminary Observations

IL-2 and IL-12 are the main antitumor cytokines in humans. Endogenous IL-2 production is generally low in metastatic cancer patients. In contrast, preliminary data suggest a possible increased secretion of IL-12 in a subgroup of metastatic cancer patients, of which the prognostic significance is still to be established. This preliminary study was performed to investigate the survival time in relation to IL-12 blood levels in patients with untreatable metastatic solid tumors. The study included 40 patients (lung cancer: 16; gastrointestinal tumors: 24). Abnormally elevated serum levels of IL-12 were observed in 15/40 (37%) patients, without any apparent relation with tumor histotype. The 1-year survival rate was significantly higher in patients with elevated IL-12 baseline values than in those with normal concentrations (8/15 vs 3/25, p < 0.01). The results of this preliminary study, which need to be confirmed in a greater number of patients by monitoring the clinical course of the neoplastic disease, seem to suggest that abnormally high baseline serum levels of the antitumor cytokine IL-12 may have a favorable prognostic significance, as they appear to be associated with a longer survival time.

Activation of the Complement System during Immunotherapy of Cancer with Interleukin-2: A Possible Explanation of the Capillary Leak Syndrome

The capillary leak syndrome, responsible for fluid loss into the interstitial space, represents one of the major cardiovascular toxicities of IL-2 during the immunotherapy of cancer. The mechanisms involved in the increased vascular permeability have still to be better understood. The present study was carried out to investigate the role of the complement system in mediating the IL-2 vascular toxicity. The study was performed in metastatic renal cancer patients, treated with IL-2 through a 24-hour i.v. infusion at a daily dose of 3 × 106 U/m2 for 5 consecutive days, corresponding to one IL-2 course. Six IL-2 courses were evaluated. C3 and C4 were measured daily during IL-2 infusion, and 2 and 5 days after its interruption. IL-2 administration induced a significant decrease in both C3 and C4 mean levels, which became within the normal range 5 days after the end of IL-2 infusion. These results show that IL-2 administration may directly activate the complement system through the classical pathway, which might play a role in determining the increased vascular permeability.

Acute Effects of Various Chemotherapeutic Combinations on Hypophyseal and Pineal Hormone Secretions in Cancer Patients

It is known that prolonged therapy with cytotoxic drugs may affect the endocrine system. The present study was carried out to establish whether administration of chemotherapeutic drugs acutely influences hypophyseal and pineal activities. Nineteen patients affected by solid tumors were included in the study, 5 of whom were treated with CMF, 4 with FEC, 4 with CEV, and 6 with CDDP. Cytotoxic drugs were intravenously administered. Venous blood samples were collected at zero time and at 30, 60, 120 and 180 min after drug administration. On a separate occasion, venous blood samples were drawn during a saline infusion only. In each sample FSH, LH, GH, PRL, TSH, Cortisol, melatonin and β-endorphin were determined by the RIA method. The only significant changes observed in this study were a rise in PRL and a decrease in β-endorphin after CDDP administration. Melatonin was enhanced after CDDP and CMF, and Cortisol decreased after CMF and FEC, but their variations were not statistically significant with respect to those seen during saline infusion.

Prolactin Secretion in Testicular Cancer Patients

The role of prolactin (PRL) in testicular function and in its disorders is still obscure. To draw some preliminary conclusions on the relation between the PRL and testis cancer, we assessed the PRL response to thyrotropin-releasing hormone (THR) in 15 patients with testicular cancer (8 seminoma; 6 nonseminoma; 1 leydigioma), and in 11 healthy male subjects as controls. The results showed that 5/15 cancer patients gave no PRL response to TRH; 4 of them had a nonseminoma and the fifth a seminomatous testis carcinoma. Patients with nonseminoma had significantly lower mean peak values of PRL after TRH than controls or patients with seminoma. The biological significance of the altered PRL response to TRH in testicular carcinoma has still to be established.

Blood Levels of IGF-I in Non-Small Cell Lung Cancer: Relation to Clinical Data

Recent observations have demonstrated that somatomedins, mainly insulin-like growth factor-I (IGF-I), are growth factors for non-small cell lung cancer (NSCLC). On the basis of this evidence, a study was started to evaluate serum levels of IGF-I in a group of untreated NSCLC patients. The study included 46 patients, 25 of whom had an operable tumor, while the other 21 showed distant organ metastases. IGF-I and GH serum levels were measured by RIA in each patient; moreover, in operable patients, hormonal detections were made either before, or 7 days after surgery. The control group comprised 38 age-matched healthy subjects. Mean serum levels of IGF-I were significantly higher in cancer patients with respect to controls, while no difference was seen in mean GH values. Moreover, patients with metastases showed significantly higher levels of IGF-I than the patients without. Within the operable group, patients with lung adenocarcinoma had higher levels of IGF-I than those with epidermoid cell carcinoma, but this difference was not significant. Finally, no significant difference in IGF-I mean values was seen before and after surgical removal of tumors. This preliminary study shows that NSCLC patients may present abnormally high levels of IGF-I. Because of the stimulating role of IGF-I on NSCLC growth, this evidence could play a role in the clinical course of neoplastic lung disease.

Endocrine Effects of Human Recombinant Interleukin-3 in Cancer Patients

It is known that several cytokines can exert hormonal effects. At present, no data are available about the possible influence of IL-3 on the endocrine system. In order to investigate the endocrine effects of IL-3 in humans, we have evaluated serum levels of Cortisol, β-endorphin, GH, PRL, FSH, LH, TSH and melatonin in response to intravenous injection of IL-3 at a dose of 1 mcg/kg b.w. at 6.00 p.m. The study was performed in 5 non-small cell lung cancer patients. GH increased significantly in response to IL-3. PRL showed a progressive decrease after IL-3 injection, but its variations were not statistically significant. All other hormones, including Cortisol, were not affected by IL-3. This preliminary study shows that IL-3 may exert endocrine effects in humans, which would seem at variance with previously reported results on most other cytokines.

Changes in Circulating Dendritic Cells and IL-12 in Relation to the Angiogenic Factor VEGF during IL-2 Immunotherapy of Metastatic Renal Cell Cancer

Angiogenesis and immunosuppression are the main biological mechanisms responsible for cancer progression. Moreover, recent observations suggesting a negative influence of angiogenesis on anticancer immunity have shown that some angiogenic factors, such as VEGF, may induce immunosuppression. In addition, the evidence of abnormally high blood levels of VEGF has been proven to be associated with resistance to IL-2 immunotherapy. The present study was performed to establish a possible relation ship between the efficacy of IL-2 cancer immunotherapy and changes in circulating levels of VEGF, IL-12, mature and immature dendritic cells (DC). The study included 25 metastatic renal cell cancer patients who underwent subcutaneus low-dose IL-2 immunotherapy (6 MIU/day for 6 days/week for 4 weeks). Immature and mature DCs were identified as CD123+ and CD11c+ cells, respectively. The clinical response consisted of partial response (PR) in five, stable disease (SD) in 11 and progressive disease (PD) in the remaining nine patients. The mean IL-12 levels observed during IL-2 immunotherapy were significantly higher in patients with PR or SD than in those with PD, whereas the mean VEGF concentrations were significantly higher in patients who had PD than in those with PR or SD. Finally, a significant increase in the mean number of circulating mature DCs occurred only in patients with PR or SD, whereas no significant change was seen in patients with PD. By contrast, no significant change was observed in the mean number of immature DCs. This study shows that the efficacy of IL-2 immunotherapy is associated with a significant increase in circulating mature DCs and IL-12, without any concomitant increase in VEGF concentrations. Further studies will be required to better define the relationship between activation of anticancer immunity and control of angiogenesis-related mechanisms.

Chemotherapy and Angiogenesis in Advanced Cancer: Vascular Endothelial Growth Factor (VEGF) Decline as Predictor of Disease Control during Taxol Therapy in Metastatic Breast Cancer

Angiogenesis is essential for tumor growth. Since vascular endothelial growth factor (VEGF) represents the main angiogenic factor, the control of VEGF secretion could constitute the most important mechanism to achieve the inhibition of angiogenesis-related processes. High blood concentrations have been proven to correlate with poor prognosis in advanced cancer. In experimental conditions, chemotherapeutic agents such as taxol appeared to inhibit VEGF-induced angiogenesis, while at present there are no data about the influence of chemotherapy on VEGF secretion in cancer patients. This preliminary study was performed to evaluate the effect of taxol therapy on VEGF secretion in advanced cancer patients in relation to the clinical response. The study included 14 patients with metastatic breast cancer who were treated with taxol monochemotherapy (175 mg/m2 i.v. every 21 days for three cycles). Serum levels of VEGF were measured by ELISA in blood samples collected before therapy and at 21-day intervals. The clinical response consisted of partial response (PR) in three and stable disease (SD) in six patients, whereas the other five patients had progressive disease (PD). Abnormally high pre-treatment levels of VEGF were seen in 8/14 patients. VEGF mean values significantly decreased during taxol therapy in patients with PR or SD, whereas no decline was observed in patients with PD. Moreover, the percent of normalization or decline greater than 50% in VEGF levels was significantly higher in patients with PR or SD than in those with PD (5/9 vs. 0/5). This preliminary study would suggest that the efficacy of taxol therapy in metastatic breast cancer - at least in terms of disease stabilization - may be associated with a decrease in VEGF blood levels followed by potential inhibition of cancer-related neovascularization.

Vascular Endothelial Growth Factor (VEGF) Serum Levels during Cancer Immunotherapy with IL-2: Preliminary Considerations

Neoangiogenesis has been proven to play a fundamental role in promoting cancer spread, and vascular endothelial growth factor (VEGF) is known to represent one of the most important angiogenic factors. The present study was planned to investigate changes in VEGF secretion in cancer patients undergoing immunotherapy with IL-2, with the aim of establishing whether VEGF variations play a role in mediating the IL-2-induced control of neoplastic diseases. The study involved 14 metastatic renal cell cancer patients treated with IL-2 immunotherapy (6 million IU/day subcutaneously for 6 days/week for 4 weeks). The clinical response consisted of partial response (PR) in 3, stable disease (SD) in 6 and progressive disease (PD) in the remaining 5 patients. VEGF serum levels were measured by an enzyme immunoassay designed to determine both bound and unbound VEGF. No significant changes in VEGF mean levels occurred during IL-2 therapy. Moreover, neither in patients with PR or SD nor in those with PD did the mean serum levels of VEGF change significantly in response to IL-2. This preliminary study seems to exclude that changes in the angiogenic factor VEGF may play a role in mediating the therapeutic efficacy of IL-2 cancer immunotherapy. However, since the method of measurement used in our study was designed to detect the total amount of VEGF, it cannot be excluded that changes in the free fraction of the molecule may occur during IL-2 cancer immunotherapy.

Dehydroepiandrosterone Sulfate (DHEAS) Secretion in Early and Advanced Solid Neoplasms: Selective Deficiency in Metastatic Disease

Several endogenous hormones have been proven to stimulate cancer growth, whereas at present very few hormones are known to display oncostatic activity. The most widely investigated antitumor hormone is the pineal indole melatonin (MLT), and cancer progression has been shown to be associated with a decline in MLT secretion. Recently, another hormone, the adrenal steroid dehydroepiandrosterone-sulfate (DHEAS), has appeared to exert antitumor effects similar to those previously described for MLT In addition, experimental studies suggest a diminished DHEAS production with neoplastic progression. This preliminary study was performed to evaluate the daily secretion of DHEAS in a group of early and advanced cancer patients. The study included 70 patients with solid tumors (gastrointestinal tract tumors: 28; breast cancer: 24; non-small cell lung cancer: 18), 28 without and 42 with distant metastases. The serum levels of DHEAS were measured by RIA in blood samples collected in the morning. The control group consisted of 100 age- and sex-matched healthy subjects. No significant difference in mean serum levels of DHEAS was observed between controls and non-metastatic patients. In contrast, metastatic patients, irrespectively of tumor histotype, showed significantly lower mean levels of DHEAS with respect to either controls or non-metastatic patients. Moreover, metastatic patients with visceral locations showed significantly lower values of DHEAS than those with bone or soft-tissue metastases. This preliminary study would suggest there to be a deficiency in the daily DHEA secretion in patients with disseminated cancer. Further studies evaluating circadian DHEAS secretion in relation to that of the pineal hormone MLT will be required to better define the biological significance of the advanced cancer-related decline in endogenous DHEAS production.

Circulating Immature and Mature Dendritic Cells in Relation to Lymphocyte Subsets in Patients with Gastrointestinal Tract Cancer

Cancer-related deficiency in circulating dendritic cells (DC), whose important anticancer role is well established, has been proven to be associated with lymphocytopenia. This study was performed to evaluate which lymphocyte subset is most markedly related to the failure of the DC system. The study included 30 patients with gastrointestinal tract cancer, 10 of whom had distant organ metastases. Immature and mature DCs were measured by FACS and monoclonal antibodies against CD123 and CD11c antigens, respectively. Low levels of immature and mature DCs were observed in 63% and 43% of patients, respectively. Patients with low levels of circulating mature DCs had significantly lower values of T lymphocytes, T helper lymphocytes and NK cells than those with normal mature DC levels. In contrast, no significant difference was seen between patients with normal or abnormally low values of immature DCs. Conversely, patients with a decreased number of T lymphocytes, T helper lymphocytes and NK cells showed significantly lower values of circulating mature DCs than those with lymphocyte subsets within the normal range, whereas no difference was seen in immature DC amounts. This study suggests that only mature DC deficiency may be associated with important lymphocyte subset alterations in cancer patients, whereas deficiency in immature DCs does not seem to be related to other immune cell disorders.