Latest Therapy for Cancer

The current conventional treatment modalities in cancer therapy include surgery, chemotherapy and radiotherapy. Despite significant advances in these therapies, a major challenge which remains unaddressed is that these treatment options affect patient’s health-related quality of life in various ways. The lack of effective treatment modalities for many inoperable solid malignancies led to the search of new therapeutic options.   Immunotherapy with Dendritic cells (DCs) has emerged as a promising new therapeutic modality for the treatment of a wide variety of malignancies. Dendritic cells are the important gatekeepers of the human immune system, defending against invaders like bacteria, viruses and cancer. Dendritic cells are major players in the control of adaptive tolerance and immunity. DCs are potent APCs which are morphologically and phenotypically heterogeneous. These cells lack lineage (Lin) specific markers, express high levels of MHC class II molecules and costimulatory molecules such as CD80 and CD86, which are required for full T-cell activation. After capturing antigen in the tissues, DCs migrate via the afferent lymph or the blood stream to the T-dependent areas of lymphoid organs where they present the antigen to T-cell, thus initiating a cascade of immune events that provides immunity. Therefore, their specific generation and adoptive transfer into patients or their in vivo targeting is attractive for clinical applications against cancer.

The characteristic of tumor cells is that these have the ability to evade immune-surveillance and are believed to be inadequate to prime immune responses in host. Our immune system can fight cancer cells generally by mounting an immune response against tumour-specific antigens or against tumour associated antigens (TAA).Recently dendritic cell therapy (DCT) has emerged as an immunotherapy for the treatment of various cancers. It is based on the concept, that the body‘s own defense system can effectively distinguish and kill cancer cells by ex vivo modification and programming of DCs to attack residual cancer cells. It is a highly personalized treatment which educates patient's DCs to fight against their tumor burden. In this way DCT is a complementary and supportative approach to the existing conventional treatment modalities. For therapeutic purposes, autologous DCs have been isolated from human bone marrow, umbilical cord blood, or peripheral blood-derived monocytes, and have been tested as vaccines for cancer therapy. The treatment protocol involves collection of circulating WBC from the blood by a process known asLeukapheresis. The mononuclear cells so collected aseptically are cultured in specific culture media under strictly controlled conditions for generation of DC. The DCs are then sducated together with tumor tissue and maturation stimuli for 8 days. Once tumor antigen specific DCs are matured, the formulation would be ready for infusion into patients. During this education process the tumor cells are destroyed and several pieces of them (TAA) are displayed on the cell surface of DC. Injection of the DC is performed every 3 to 4 weeks for up to nine months and is generally well tolerated and is not associated with any adverse side effects. After infusion into the patients, TAAs expressed by DCs are recognized by other cellular effector cells particularly T cells that are then travelling through the body and destroy the tumor cells. In this way, DC cancer vaccines elicit a more potent active immunity in the patients in whom the immune surveillance has failed. Several approaches are being explored to explore the safety and efficacy of the DC-based vaccine as cellular adjuvants in cancer treatments. Ex vivo generated DCs loaded with tumor-specific antigens are capable of stimulating powerful antitumor immune responses, and over 200 clinical trials have been reported. These results pertaining to safety, tolerability and efficacy suggest the potential of dendritic cell vaccine as potent immune regulators in cancer immunotherapy.