Regulators of the cell cycle such as cyclin E play an important part in neoplasia. The cyclin E protein forms a partnership with a specific protein kinase. This complex phosphorylates key substrates to initiate DNA synthesis. Cyclin-dependent kinase inhibitors (CKIs) are able to suppress the activity of cyclin E. Various substances (including proteins produced by oncogenic viruses) affect cyclin E directly or indirectly through an interaction with CKIs. These interactions are important in elucidating the mechanisms of neoplasia. They may also provide prognostic information in a wide range of common cancers. Cyclin E may even be a target for treatment of cancers in the future. (+info)
Rhabdomyosarcoma: an overview.
Rhabdomyosarcoma (RMS) is a malignant tumor of mesenchymal origin thought to arise from cells committed to a skeletal muscle lineage. With approximately 250 cases diagnosed yearly in the United States, it is the third most common extracranial solid tumor of childhood after Wilms' tumor and neuroblastoma. Important epidemiologic, biologic, and therapeutic differences have been elucidated within the RMS family. Common sites of primary disease include the head and neck region, genitourinary tract, and extremities. A site-based tumor-nodes-metastasis staging system is being incorporated into use for assessing prognosis and assigning therapy in conjunction with the traditional surgicopathologic clinical grouping system. The development of intensive multimodality treatment protocols tested in large-scale international trials has resulted in significant improvements in outcome, especially for patients with local or locally extensive disease for whom a 60%-70% disease-free survival can be expected. Despite aggressive approaches incorporating surgery, dose-intensive combination chemotherapy, and radiation therapy, the outcome for patients with metastatic disease remains poor. Future challenges include the development of less toxic therapy for patients with localized disease and new approaches for patients with metastatic disease. (+info)
Outcome of postchemotherapy surgery after treatment with methotrexate, vinblastine, doxorubicin, and cisplatin in patients with unresectable or metastatic transitional cell carcinoma.
PURPOSE: The role of postchemotherapy surgery for patients with metastatic transitional cell carcinoma (TCC) is controversial. We retrospectively analyzed our experience with patients who underwent postchemotherapy surgery after methotrexate, vinblastine, doxorubicin, and cisplatin (M-VAC) chemotherapy to assess an impact on long-term survival. PATIENTS AND METHODS: This report is based on the retrospective analysis of 203 patients with unresectable primary tumors or metastatic TCC, previously reported in five trials of M-VAC chemotherapy. Fifty patients underwent postchemotherapy surgery for suspected or known residual disease. Characteristics of patients selected for surgery, results of surgery, and the impact of surgery on survival were assessed. RESULTS: In 17 patients, no viable tumor was found at postchemotherapy surgery, pathologically confirming a complete response to chemotherapy. Three patients had unresectable residual TCC. In 30 patients, residual, viable TCC was completely resected, which resulted in a complete response to chemotherapy plus surgery. Ten (33%) of these 30 patients remained alive at 5 years, similar to results observed for patients who attained a complete response to chemotherapy alone (41%). Analysis by baseline extent of disease suggested that patients with unresectable primary tumors or with metastases restricted to lymph node sites were most likely to survive for 5 years. CONCLUSION: Postchemotherapy surgical resection of residual cancer may result in 5-year disease-free survival in some patients who would otherwise succumb to disease. Optimal candidates include patients whose prechemotherapy sites of disease are restricted to the primary or lymph node sites and who have a major response to chemotherapy. (+info)
Pathways of O-glycan biosynthesis in cancer cells.
Glycoproteins with O-glycosidically linked carbohydrate chains of complex structures and functions are found in secretions and on the cell surfaces of cancer cells. The structures of O-glycans are often unusual or abnormal in cancer, and greatly contribute to the phenotype and biology of cancer cells. Some of the mechanisms of changes in O-glycosylation pathways have been determined in cancer model systems. However, O-glycan biosynthesis is a complex process that is still poorly understood. The glycosyltransferases and sulfotransferases that synthesize O-glycans appear to exist as families of related enzymes of which individual members are expressed in a tissue- and growth-specific fashion. Studies of their regulation in cancer may reveal the connection between cancerous transformation and glycosylation which may help to understand and control the abnormal biology of tumor cells. Cancer diagnosis may be based on the appearance of certain glycosylated epitopes, and therapeutic avenues have been designed to attack cancer cells via their glycans. (+info)
Critical evaluation of lymphocyte functions in urological cancer patients.
One hundred three patients with varying stages of urological cancer (bladder, prostate, kidney) were investigated with regard to the following lymphocyte functions. T-cells were assessed numerically (E rosettes), their blastogenic response to phytohemagglutinin (pHA) was determined, and their cytotoxic potential against heterologous target cells in short-term presence of PHA (e.i., PHA-dependent cellular cytotoxocity) was evaluated. Similarly, B cells were numerically assessed (EA rosettes), and their function was evaluated by antibody-dependent cellular cytotoxicity against antibody-coated deterologous target cells. The data on cancer patients, divided on the basis of extent of disease and prior radiation therapy, were compared to those of normal young and age-matched controls. Our investigations emphasize the importance of the following factors: (a) comparison of data with age-matched controls, since several lymphocyte functions appear to change with age; (b) use of multiple controls to compensate for the inherent variability found in certain tests; (c) minimized contamination by nonlymphoid cells in the purified cell preparation; and (d) the influence of certain treatment regimens (radiation, chemotherapy, etc.) on the results. Radiotherapy significantly depressed T-cell number with a depression of PHA blastogenic responses as well as PHA-dependent cellular cytotoxicity. When all of these conditions were taken into account, the urological cancer patients as a group were found to have a lower proportional value of E rosettes (T-cells) and a reduced PHA blastogenic responsiveness. Certain cancer patients displayed an elevated PHA-dependent cellular cytotoxicity as compared to age-matched controls, which may indicate the presence of activated cells in the presence of tumors. With this identification of a group of cancer patients with markedly depressed E rosette values and PHA responsiveness, it will now be possible to follow them clinically in comparison with a group of cancer patients with normal T-cell functions. (+info)
Correlations among cutaneous reactivity to DNCB, PHA-induced lymphocyte blastogenesis and peripheral blood E rosettes.
Comparisons of the results obtained in a study of fifty-two patients with genitourinary malignancies using three assays to monitor the thymus-dependent immune system (delayed cutaneous hypersensitivity to DNCB, PHA-induced lymphocyte blastogenesis, and peripheral blood E rosette-forming lymphocyte counts) yielded statistically significant positive correlations between the DNCB and PHA assays in twenty-one of twenty-eight instances, the DNCB and E rosette assays in thirteen of sixteen instances, the PHA and E rosette assays in twenty-eight of thirty-six instances, and among the DNCB, PHA and E rosette assays in ten of fourteen instances. The results suggest that both PHA-stimulated lymphocyte blastogenesis and peripheral blood E rosette-forming lymphocyte levels provide meaningful in vitro correlates of cell-mediated immunity. (+info)
Intestinal failure after surgery for complicated radiation enteritis.
Between 1983 and 1997, a total of 16 patients were referred to a tertiary Intestinal Failure Unit (IFU) following surgery elsewhere for complications of radiation enteritis. Eleven were female with a mean age of 43 years (range 21-71 years) and the most common primary site of malignancy was genitourinary (n = 13). Patients had undergone an average of two laparotomies (range 1-7 laparotomies) for complications of radiation enteritis prior to transfer to the IFU. On admission, the principal problem in eight patients was persisting intestinal fistulation, four patients had continuing intestinal obstruction and four had the short bowel syndrome after extensive intestinal resection. Only one patient had evidence of residual malignancy; this patient with short bowel syndrome was allowed home without invasive therapy. Of the remaining 15 patients, 12 required an abdominal surgical procedure, while three were discharged without further surgery after training for home parenteral nutrition (HPN). Following abdominal surgery, five patients died in hospital, but the remaining seven patients went home alive--including two further patients on HPN. Overall, of the 15 patients referred with intestinal failure after surgery for complications of radiation enteritis and actively treated, one-third died in hospital and a further third required institution of HPN before being able to be discharged home. (+info)
Incidence of cancer after prophylaxis with warfarin against recurrent venous thromboembolism. Duration of Anticoagulation Trial.
BACKGROUND: The length of time after an episode of venous thromboembolism during which the risk of newly diagnosed cancer is increased is not known, and whether vitamin K antagonists have an antineoplastic effect is controversial. METHODS: In a prospective, randomized study of the duration of oral anticoagulation (six weeks or six months) after a first episode of venous thromboembolism, patients were questioned annually about any newly diagnosed cancer. After a mean follow-up of 8.1 years, we used the Swedish Cancer Registry to identify all diagnoses of cancer and causes of death in the study population. The observed numbers of cases of cancer were compared with expected numbers based on national incidence rates, and the standardized incidence ratios were calculated. RESULTS: A first cancer was diagnosed in 111 of 854 patients (13.0 percent) during follow-up. The standardized incidence ratio for newly diagnosed cancer was 3.4 (95 percent confidence interval, 2.2 to 4.6) during the first year after the thromboembolic event and remained between 1.3 and 2.2 for the following five years. Cancer was diagnosed in 66 of 419 patients (15.8 percent) who were treated for six weeks with oral anticoagulants, as compared with 45 of 435 patients (10.3 percent) who were treated for six months (odds ratio, 1.6; 95 percent confidence interval, 1.1 to 2.4). The difference was mainly due to the occurrence of new urogenital cancers, of which there were 28 cases in the six-week group (6.7 percent) and 12 cases in the six-month group (2.8 percent) (odds ratio, 2.5; 95 percent confidence interval, 1.3 to 5.0). The difference in the incidence of cancer between the treatment groups became evident only after two years of follow-up, and it remained significant after adjustment for sex, age, and whether the thromboembolism was idiopathic or nonidiopathic. Older age at the time of the venous thrombosis and an idiopathic thromboembolism were also independent risk factors for a diagnosis of cancer. No difference in the incidence of cancer-related deaths was detected. CONCLUSIONS: The risk of newly diagnosed cancer after a first episode of venous thromboembolism is elevated during at least the following two years. Subsequently, the risk seems to be lower among patients treated with oral anticoagulants for six months than among those treated for six weeks. (+info)