Vitamin D receptor expression as a predictive marker of biological behavior in human colorectal cancer.

To date, none of the potential biological markers in colorectal cancer attempts to link the epidemiological data with the molecular biology of the disease. In an attempt to link dietary and epidemiological factors and to obtain a better understanding of the molecular biology of colorectal cancer, we measured vitamin D receptor (VDR) expression in 75 human colorectal cancers as a potential predictive marker of the biological behavior of the disease. Our results showed that a high level of VDR expression was associated with a favorable prognosis. The results of the studies reinforce the potential role that VDR may play in the development of the pathogenesis of colorectal cancer. Larger studies looking exclusively at stage I and stage II disease will hopefully lead to the development of a sensitive hormonal marker that can be used to predict the biological behavior of colorectal cancer, identifying at-risk patients in need of adjuvant treatment.

Extended surgical resection in T4 gastric cancer.

BACKGROUND: Some physicians still consider invasion of adjacent organs by the carcinoma of stomach as a sign of incurable disease. METHODS: This retrospective study has been done with particular reference to 353 T4 gastric cancer patients who underwent combined gastrectomies with adjacent organs. RESULTS: Subtotal gastrectomy was performed in 237 (67.1%) patients and total gastrectomy was performed in 116 (32.9%) patients. Organs most commonly resected with the stomach were the transverse colon in 159 (45%) cases, the tail of pancreas and spleen in 150 (42.5%), the left lobe of liver in 101 (28.5%), and the head of pancreas in 37 (10.5%) patients. A total of 110 postoperative complications occurred in this subset of patients corresponding to a complication rate of 31.2%. A total of 48 postoperative deaths occurred in this subset of patients corresponding to a mortality rate of 13.6%. The 5-year survival rate for all patients who underwent combined gastrectomy with adjacent organs was 25%. Of the node-negative T4 gastric cancer resections, 37% survived 5 years whereas the T4 node-positive resections have only a 15% 5-year survival. CONCLUSIONS: Patients who present with T4 gastric cancer (about 20% of the patient population) will benefit from aggressive en bloc surgical resection and should not be considered unresectable.

Apoptosis induced by hyperthermia and verapamil in vitro in a human colon cancer cell line.

The aim of this study was to determine the mechanisms responsible for the growth inhibitory effect of hyperthermia and verapamil in human colon cancer cell line HT-29. Apoptotic cell death was verified by flow cytometry analysis. The effect of treatment with hyperthermia and verapamil on the expression of apoptosis-associated proteins including Bcl-2, p53, bax, and c-Myc was studied by Western blot analysis. Changes in intracellular calcium homeostasis was analysed by fluorescence microscopy. The combination of 42 degrees C hyperthermia and verapamil caused a significant delay of human colon cancer cell proliferation as a result of apoptosis. Administration of these agents alone did not cause any cell inhibitory effect. Our experiments have shown that HT-29 cells constitutively express apoptosis-promoting proteins, such as Bax and c-Myc, while they fail to produce Bcl-2. Therefore, we hypothesize that HT-29 cells must have Bcl-2 independent pathways to protect cells against death-inducing signals. Also, apoptosis of HT-29 cells produced by hyperthermia in the presence of verapamil is a p53-independent process. Verapamil, when it did not act as a calcium channel blocker or inhibitor of release from intracellular storages under hyperthermic conditions, accelerated the increase of [Ca2+]i in HT-29 cells which resulted in programmed cell death (apoptosis).

Carcinoma of the stomach following the Chernobyl nuclear accident.

Medical consequences of many nuclear accidents on humans are well studied, but the results pertaining to gastric cancer patients who were exposed to radiation as a result of the Chernobyl nuclear accident have not been analysed. In this study, the outcome of the surgical treatment of 68 gastric cancer patients who were exposed to radiation as a result of the Chernobyl nuclear accident was compared with that of 117 consecutive gastric cancer patients from uncontaminated areas of the Ukraine. Patients in the study group was significantly younger than that of the control group. Comparative analysis showed the same frequency of regional metastases (65.7% versus 71.1%, P > 0.05), but a smaller number of distant metastases (23.8% versus 38.1%, P < 0.05) in the study group. 41.2% of patients in the study group underwent total gastrectomy compared to 19.6% of patients in the control group (P = 0.002). Postoperative complications developed in 13.2% of patients in the study group, while postoperative mortality in the study group was 7.3% compared to 1.7% in the control group. A significant decrease in CD16 cells was noted in patients from the study group following the operative procedure. Young age, invasive tumours with smaller number of distant metastases, frequent necessity for total gastrectomy and combined operations with adjacent organs, a higher level of postoperative morbidity and mortality and low levels of natural killer cells (CD16+) with a tendency to decrease after surgery are characteristic of patients with carcinoma of the stomach affected by the Chernobyl accident.

TNM staging of pancreatic carcinoma using helical CT.

OBJECTIVE: The purpose of this study was to determine the accuracy of helical CT scanning in predicting the stage of carcinoma of the exocrine pancreas using TNM staging guidelines and in predicting resectability of carcinoma of the exocrine pancreas. MATERIALS AND METHODS: Twenty-six patients with proven adenocarcinoma of the pancreas underwent uniphasic or biphasic helical CT scanning. Two observers unaware of the patient's surgical stage evaluated the CT examinations using the TNM system (with specific assessment and description of disease sites). In addition, the two observers rated confidence of nonresectability using a 5-point scale (ranging from 1, definitely resectable, to 5, definitely not resectable). Observer results and preoperative interpretations were compared with surgical findings. RESULTS: Nineteen of 26 patients had nonresectable disease. The combined observer scores showed correct determination of T stage in 77% of patients, of N stage in 58%, and of M stage in 79%. The overall accuracy in determining lack of resectability was 96% and 84% for the two observers. All errors in determining resectable versus nonresectable disease occurred when the observer was not maximally confident of his or her diagnosis. CONCLUSION: Helical CT is an effective screening technique for assessing T and M stages of pancreatic carcinoma. However, helical CT is poor at detecting regional lymph node involvement. In patients with equivocal T-stage findings (such as questionable venous involvement), other studies such as endoscopic sonography may be of value.

Primary non-Hodgkin's lymphoma of the stomach: three radical modalities of treatment in 75 patients.

BACKGROUND: Non-Hodgkin's lymphoma (NHL) remains a rare form of gastric malignancy, with a rising incidence. Approaches to treatment vary from surgery alone to conservative management. METHODS: To determine the optimal scheme of treatment, a randomized clinical trial was undertaken. Seventy-five patients were randomized into three groups: A-surgery alone (25), B-surgery followed by chemotherapy (29), and C-radiation therapy followed by surgery and chemotherapy (21). Forty-nine patients had stage IE and 26 had stage IIE disease. Chemotherapy (COP and COPP) consisted of 6 courses during a 1-year period, with the courses being 6 weeks apart. RESULTS: Subtotal gastrectomy was performed in 26 patients. Forty-nine patients underwent total gastrectomy. Postoperative complications occurred in 6 (8%) patients: 3 (12%) in group A, 2 (6.9%) in group B, and 1 (4.7%) in group C. Postoperative mortality occurred in 2 (8%) patients in group A (2.7% of all patients). An increase in hospital admissions number per year and decrease of mean age of patients with NHL of the stomach after the Chernobyl accident on April 26, 1986 was noted. CONCLUSIONS: Improved survival in gastric NHL was achieved by a combination of preoperative radiation with surgery and postoperative chemotherapy, presumptively through the management of local and systemic disease.

The effect of 1, 25-dihydroxyvitamin D3 on the growth of soft-tissue sarcoma cells as mediated by the vitamin D receptor.

BACKGROUND: Soft-tissue sarcomas, malignant neoplasms originating from mesenchymal tissue, are rare but highly aggressive tumors. Present modes of therapy are associated with high rates of recurrence. 1, 25-Dihydroxyvitamin D3, the active metabolite of vitamin D, serves as a potent antiproliferative agent in human cancer cells. METHODS: In this study, six soft-tissue sarcoma cell lines were analyzed for vitamin D receptor (VDR) expression, which was then correlated with the degree of growth inhibition in response to 1, 25-dihydroxyvitamin D3. These cell lines included rhabdomyosarcoma (HS729, A204), fibrosarcoma (HS913t), synovial sarcoma (SW982), liposarcoma (SW872), and leiomyosarcoma (SKLMS-1). The level of VDR messenger RNA (mRNA) expression was determined using a ribonuclease protection assay, and functional receptor content was determined by using a ligand-binding assay. Growth studies, including [3H]thymidine uptake and growth curves, were performed on two of the six cell lines that expressed the highest and lowest receptor levels. RESULTS: Ribonuclease protection and ligand-binding assays demonstrated variable levels of VDR, with HS729 showing high expression and A204 showing no expression. In HS729, [3H]thymidine uptake was significantly decreased at 10(-7) M (33%) and 10(-6) M (40%) 1, 25-dihydroxyvitamin D3. Growth curve studies showed significant growth inhibition of 55% at 10(-6) M. A204 cells showed no growth inhibition upon treatment with 1, 25-dihydroxyvitamin D3. CONCLUSION: This study demonstrates the existence of VDR in soft-tissue sarcoma cells and suggests a correlation between the level of VDR in cells and the degree of growth inhibition caused by 1, 25-dihydroxyvitamin D3 which may potentially serve as an alternative form of therapy for soft-tissue sarcomas.

Postoperative complications requiring relaparotomies after 700 gastretomies performed for gastric cancer.

BACKGROUND: Prevention of fatal postoperative complications and improved management of patients with complications are important means of increased survival in gastric cancer patients. PATIENTS AND METHODS: A study of 700 patients undergoing gastrectomy was performed to examine factors that contributed to a high rate of postoperative complications. RESULTS: Of 700 patients undergoing gastrectomy for adenocarcinoma, 40 (5.7%) underwent reexploration because of serious complications. The frequency of the relaparotomies varied from 2.1% and 4.4% after regular subtotal and total gastrectomies, respectively, to 20% and 30.4% after palliative and conventional total gastrectomies, respectively. The complications that required reexploration most frequently were anastomotic leakage and incompetence of sutures (11, 27.5%), intra-abdominal abscesses (8, 20%), and pancreatic necrosis (7, 17.5%). A combination of preventive measures allowed the attainment of low rates of esophagojejunal anastomotic leakage (0.8%). CONCLUSION: We believe that the decision to perform an urgent reexploration, based on clinical findings, should generally be made by a group of experienced surgeons (not only the primary surgeon). Timely relaparotomy prevented death in 37.5% of the patients with serious acute postoperative complications.

Vitamin D receptor and growth inhibition by 1,25-dihydroxyvitamin D3 in human malignant melanoma cell lines.

The expression of vitamin D receptors (VDR) and growth inhibition induced by 1,25-dihydroxyvitamin D3 have been noted in certain human malignant melanoma cell lines. In this study, widely disparate levels of VDR mRNA expression were demonstrated in a panel of eight human malignant melanoma cell lines. Quantitation of receptor level by ligand binding assay showed a similar pattern. Proliferation and growth curve analysis was performed in two cell lines: RPMI 7951 (high VDR) and SK-MEL-28 (low VDR). Significant growth inhibition was noted in RPMI 7951 cells at 10(-9) M 1,25-dihydroxyvitamin D3. SK-MEL-28 cells, which express much lower levels of VDR, did not show any growth inhibition except at extremely high concentrations of 1,25-dihydroxyvitamin D3, namely 10(-5) M. These findings suggest a receptor-mediated mechanism of growth inhibition for 1,25-dihydroxyvitamin D3 and a role for this hormone in the growth of malignant melanoma cells.

Modulation of vitamin D receptor and estrogen receptor by 1,25(OH)2-vitamin D3 in T-47D human breast cancer cells.

1,25(OH)2-Vitamin D3 inhibits breast cancer cell proliferation through interaction with the vitamin D receptor (VDR). Regulation of VDR is under the influence of several factors which include the functional ligand for this receptor (1,25(OH)2-vitamin D3) as well as heterologous steroid hormones. We evaluated the nature of homologous regulation in T-47D human breast cancer cells with a radiolabelled ligand binding assay and a ribonuclease protection assay for VDR. Significant VDR up-regulation, as measured by hormone binding assays, occurred with pre-incubations with 10(-9)M through 10(-6)M 1,25(OH)2-vitamin D3 (P < 0.05). A 7-fold VDR up-regulation with 10(-8)M 1,25(OH)2-vitamin D3 occurred at 4 h treatment and was not associated with an increase in VDR mRNA expression on ribonuclease protection assay. This supports the hypothesis that up-regulation of VDR is probably the result of ligand-induced stabilization of pre-existing receptor. All-trans-retinoic acid, the progesterone analog R-5020, and prednisone were found to induce heterologous up-regulation of the VDR. We then determined with ligand binding assays whether 1,25(OH)2-vitamin D3 could influence receptor levels for another hormone in a manner analogous to the heterologous regulation of VDR. Regulation of estrogen receptor (ER) by 1,25(OH)2-vitamin D3 was studied in T-47D and MDA-MB-231 breast cancer cells. Incubation of T-47D cells, which are ER (+), with 10(-8)M 1,25(OH)2-vitamin D3 did not result in up-regulation of ER. Yet estrogen binding was significantly up-regulated in a cell line that is ER(-), MDA-MB-231. The increased estrogen binding was associated with a shift in binding affinity and ribonuclease protection assay showed absence of ER mRNA in these cells, suggesting an up-regulation of estrogen binding proteins and not of the ER itself.

The antiproliferative effect of vitamin D analogs on MCF-7 human breast cancer cells.

We analyzed the antiproliferative effect of 1,25-dihydroxyvitamin D3 and four vitamin D analogs on MCF-7, a human breast cancer cell line known to express the vitamin D receptor. Growth curve studies and [3H]thymidine incorporation assays were used to assess the antiproliferative effect of 1,25-dihydroxyvitamin D3 (vitamin D), Ro 23-7553, Ro 24-5531, Ro 25-5317, and Ro 24-5583. Growth of MCF-7 cells was significantly inhibited by 1,25-dihydroxyvitamin D3 and all four analogs at 10(-8) M (P < 0.05). MCF-7 cells treated with analog had significantly less [3H]thymidine incorporation than cells treated with 1,25-dihydroxyvitamin D3 (P < 0.05). The affinity of the analogs for the vitamin D receptor was similar to that of 1,25-dihydroxyvitamin D3. These results demonstrate that analogs of 1,25-dihydroxyvitamin D3 are potent antiproliferative agents on human breast cancer cells and that this activity is likely mediated through the vitamin D receptor.

The effect of extracellular calcium on colonocytes: evidence for differential responsiveness based upon degree of cell differentiation.

Calcium supplementation decreases the incidence of colon cancer in animal models and may prevent colon cancer in man. Potential mechanisms include binding of mitogens and direct effects of calcium on colonic epithelial cells. In this study, the effects of extracellular calcium on epithelial cell growth and differentiation were studied in three colon carcinoma and two colonic adenoma cell lines. The characteristics studied included morphology, cell cycle kinetics, [Ca2+]IC (intracellular calcium concentration), proliferation, and expression of differentiation markers such as carcinoembryonic antigen (CEA) and alkaline phosphatase (AP). Sodium butyrate (NaB) and 1,25-dihydroxyvitamin D3 were used as controls in the latter three assays as these two agents are known differentiating agents. Alteration of [Ca+2]EC (extracellular calcium concentration) did not affect carcinoembryonic antigen (CEA) or alkaline phosphatase (AP) expression. NaB enhanced the expression of AP three-fold and CEA five-fold. This effect was augmented by increasing [Ca2+]EC. The exposure of cells to 1,25-(OH)2-Vitamin D3 increased CEA but not AP. [Ca2+]IC increased in response to 1,25-(OH)2-vitamin D3 and NaB but not with variation in [Ca2+]EC. Increased [Ca2+]EC inhibited proliferation of well-differentiated cells, but had no effect on poorly-differentiated cells. Morphological studies showed that extracellular calcium was necessary for normal cell-cell interactions. These studies have demonstrated direct effects of calcium on colonic epithelial cells which may contribute to the protective effects of dietary calcium against colon cancer. Loss of responsiveness to the antiproliferative effects of [Ca2+]EC with de-differentiation suggests that calcium supplementation may be most beneficial prior to the development of neoplastic changes in colonic epithelium.

Radical treatment of locally recurrent gastric cancer.

Locally recurrent gastric cancer develops in 45 per cent of resected patients. This study assessed the impact of an aggressive search for recurrence after radical operations and the use of reoperative and adjuvant therapy in this setting. From 1983 to 1990, 75 patients were explored for regionally recurrent gastric cancer. Resection was possible in 40 (53.5%), and palliative bypass was possible in 19 (25.3%); exploration only was performed in 16 (21.4%). Among resectable patients, gastrectomy was performed in 22 (55%) and gastrectomy with adjacent organ resection in 18 (45%) with an overall operative mortality of 15% (6 patients). Mean duration of life after bypass was 3.1 months; after exploration 4.5 months. Fifteen (40.6%) were not candidates for radiation or chemotherapy, 13 (31.2%) received preoperative radiotherapy (20 Gy), and 12 (28.2%) received postoperative systemic chemotherapy. Two-year survival after radical treatment was as follows: surgery alone 20%; radiotherapy and surgery 31.3%; surgery and chemotherapy 66.4%. These preliminary results indicate that re-excision benefits selected patients with recurrent gastric cancer. Patients receiving radiotherapy and chemotherapy tended toward improved survival.

Preoperative superselective intraarterial chemotherapy in the combined treatment of gastric-carcinoma.

146 patients were included in this prospective, randomized study: 50 patients were treated with surgery alone (S), 49 patients received pre-operative intravenous (systemic) chemotherapy (IVCH) and 47 patients received pre-operative superselective intra-arterial chemotherapy (IACH). Left gastric and right gastroepiploic arteries were catheterized for IACH. After IACH a measurable tumor response was registered in 87.1% of the patients; in 61.6% no residual tumor was found in the resected stomach. IVCH produced no survival benefit compared to surgery alone. IACH plus S improved 3-year survival relative to surgery alone (89.3+/-2.1% vs 35.5+/-4.9%; p<0.01). Projected 5-year survival in the IACH+S group is 78.1% vs. 30.1% with surgery alone (p<0.01). IACH provided substantial survival benefit when used as a component of combined modality gastric cancer treatment.

The effect of hyperthermia and verapamil on primary and metastatic colon adenocarcinoma cell-lines - inhibition of proliferation, cell-cycle distribution and onset of apoptosis.

Administration of the combination of hyperthermia and verapamil significantly decreased proliferation of HT-29 and SW-620 cells while hyperthermia or verapamil alone did not cause such growth inhibition. DNA histograms showed no significant changes in the cell cycle distribution of either cell line after hyperthermia treatment. After the administration of verapamil, a significant increase in both cell lines of the G(2)-M fraction was seen at 6, 20, and 30 hours in comparison to control with a concomitant decrease in G(1) phase population. The combination of hyperthermia and verapamil resulted in an accumulation of cells in G(2)-M phase with subsequent release from the arrest and appearence the cells showing fragmentation of chromatin into nucleosomal oligomers, the hallmark of programmed cell death (apoptosis).

Growth-inhibition of human-melanoma cells by vitamin-d analogs.

The antiproliferative activity of 1,25(OH)(2)-vitamin D-3, and four vitamin D analogs was assessed in RPMI-7951, a human melanoma cell line which expresses the vitamin D receptor. Proliferation assays consisted of a [H-3]-thymidine incorporation assay, and a 6-day growth study. The affinity of vitamin D analogs for vitamin D receptor relative to 125(OH)(2)-vitamin D-3 was determined with a hydroxyapatite-based competitive binding assay. For the proliferation assays, cells were treated with 10(-8) M 1,25(OH)(2)-vitamin D-3, 1,25(OH)(2)-16-ene-23-yne-vitamin D-3 (Ro 23-7553), 1,25(OH)(2)-16-ene-23-yne-26,27-hexafluoro-vitamin D-3 (Ro 24-5531), 1,25(OH),-16,23Z-diene-26,27-hexafluoro-vitamin D-3 (Ro 25-5317), and 1 alpha-fluoro-25(OH)- 16-ene-23-yne-hexafluoro-vitamin D-3 (Ro 24-5583). 1,25(OH)(2)-vitamin D-3 and the four analogs all significantly inhibited melanoma cell growth (P<0.05). Competitive binding of the vitamin D analogs to vitamin D receptor ranged from 51% to 72% that of 1,25(OH)(2)-vitamin D-3, suggesting a receptor-mediated response. These results demonstrate that analogs of 1,25(OH)(2)-vitamin D-3 are potent antiproliferative agents in human melanoma cells in vitro.