Immunotherapy of Cancer

Immunotherapy of Cancer

Immunotherapy of cancer can be considered as the following two broad groups:

i.               Antigen-nonspecific treatment

ii.               Antigen-specific treatment

◗ Antigen-nonspecific treatment

This includes treatment with various nonspecific immune modulators.

·           Bacillus Calmette–Guérin (BCG) vaccine has been shown to possess antitumor activity. The vaccine when injected directly into certain solid tumors may cause regression of tumor. Antitumor effect of tumor is believed to be due to activation of macrophages and NK cells. The BCG therapy has been reported to be beneficial in treatment of bladder cancer, malignant melanomas, stage I lung cancer, and cer-tain leukemias.

·           Corynebacterium parvum also possesses antitumor activities.Its antitumor effect is due to its ability to stimulate macro-phages and B cells. It shows a synergistic effect when used in conjunction with cyclophosphamide. It is found to be useful in treatment of metastatic breast cancer and various types of lung cancer.

·           Other nonspecific immune modulators include (i) dinitro-chlorobenzene (DNCB), evaluated in squamous and basal carcinoma, (ii) levamisole for stimulating cell-mediated immunity and macrophage function, (iii) interferon to stim-ulate NK cell function, (iv) cytokine IL-2 to stimulate killing of cancer cells by cytotoxic T cells, (v) NK cells, and mac-rophages, thymic hormones to restore T cell function, and (vi) tuftsin to stimulate phagocytic cells.

◗ Antigen-specific treatment

Antigen-specific treatment includes (a) vaccination with tumor antigen, (b) treatment with transfer factor, (c) treatment with immune RNA, (d) treatment with monoclonal antibodies raised against tumor-associated antigens (TAAs) given alone or in conjunction with cytotoxic drug, and (e) modification of tumor antigenicity by treatment with neuraminidase.