But most cancers, such as colorectal, lung, prostate, breast, lymphoma, leukemia, glioma, kidney and pancreas cancers are not caused by infections. Researchers are trying to invent effective therapeutic vaccines employing cytotoxic T cells, in conjunction with different cytokines and different adjuvants, trigger the antigen presentation along with MHC- I which could activate CD8+ T cells to specifically attack cancer cells. Several therapeutic cancer vaccine candidates have shown some promise in clinical trials, but yet to be approved.

Several types of cancer treatment vaccines are being studied with a few reaching late
stage clinical trials, including tumor cell vaccines, antigen vaccines, dendritic cell vaccines and DNA vaccines.

How far non-specific immune boosts are successful?
Non-specific boosts do not target a certain cell or antigen but they stimulate the immune system against cancer cells. The following immune boosters are prominently used to treat cancer.

Interleukins
Interleukins are a group of cytokines that act as chemical signals between white blood cells. Interleukin-2 (IL-2) helps immune system cells to grow and divide more quickly. IL-2 is so far approved to treat advanced kidney cancer and metastatic melanoma either as a single drug or in combination with chemotherapy or with other cytokines such as interferon-alfa. It is also being studied for use as an adjuvant along with some vaccines.
Other interleukins, such as IL-7, IL-12, and IL-21 are now being studied for use against cancer too, both as adjuvants and as stand-alone agents.

Interferons
IFN-alfa is a cytokine used to treat cancer. It boosts the ability of certain immune cells to attack cancer cells. It may also slow the growth of cancer cells directly as well as the blood vessels that tumors need to grow. The FDA has approved IFN-alfa for use against various cancers.