Background: Conventional cancer therapies such as chemotherapy and
radiotherapy are often characterised by lack of tumor specificity, increased resistance
of tumors to drugs, failure to detect metastases and undesirable side effects. Several
years back, William Coley’s pioneering work on the use of bacteria opened up the
new field of cancer immunotherapy. The search for alternative and better strategies in
cancer treatment is an ongoing process.
Methods: Articles related to the therapeutic efficacies of different bacterial species
against cancer were searched in different scientific journals and databases. This review
summarizes the studies on the expediency of different bacterial species in cancer
treatment particularly the potential therapeutic efficiency of Mycobacteria.
Results: A strain of Mycobacterium bovis, i.e. Bacillus Calmette Guerin, is approved for the treatment
of bladder carcinoma. Also, treatment with Mycobacterium vaccae improves the quality of life of patients
suffering from some tumors. Recent studies have revealed the efficacy of Mycobacterium indicus
pranii in inducing a Th1 priming environment and reducing the in vivo tumor growth in several animal
Conclusions: The immunotherapeutic potential of different mycobacterial species warrant clinical investigations
for a wide range of tumors and may open up a new dimension in cancer therapy. Further
studies and technological innovations are likely to shed new light on host responses to tumors, provide a
promising regimen of cancer therapeutics and improve the quality of life of cancer patients.