Health and Prostate

Traditional Endpoints Clinical trials in oncology have traditionally used the end-points of tumor response and survival (median survival time) to determine the efficacy of a given treatment. Several problems arise when attempting to evaluate prostate cancer responses by these criteria. First, patients with bidimensionally measurable tumor masses in whom response or progression can be accurately assessed account for only 20% of patients with prostate cancer. The majority of patients have bone metastases that are difficult to quantitate accurately. These osseous lesions may exhibit a delayed treatment response and likely represent a biologically different disease than soft tissue metastases. Second, very active agents used in large randomized studies are required to demonstrate a small benefit in both androgen-dependent and androgen-independent disease. Third, survival figures have been difficult to interpret because many patients receive treatment with a series of therapies over a prolonged time interval as a result of relapses and disease progression. It is then difficult to attribute a survival Read more [...]

Manipulation of the immune system to eradicate cancer is an attractive approach in that, in contrast to chemotherapeutic approaches, normal host cells are theoretically spared in the process while the immune system specifically targets the malignant cells. Although the immune system can recognize very small differences between cells and orchestrate cytotoxic responses against these foreign cells, the tumor antigens on cancer cells, unlike the antigens on bacteria or viruses, are not very immunogenic. Current approaches in immunotherapy of cancer have therefore focused on enhancing endogenous immunity or by genetically altering the system at some point in order to affect cell kill. Biologic Response Modifiers The interferons (interferons) are biologic response modifiers with antiproliferative, immunomodulatory, and differentiative effects whose mechanisms of action with respect to tumor cell kill remain unclear. Studies have demonstrated the ability of the interferons (alpha or gamma) to enhance the expression of tumor-associated antigens by either increasing the number of positive cells or by Read more [...]