Objective To evaluate the potential of heat-killed Results SRL172 was eCective as an adjuvant to autologous whole tumour cell vaccination in the prevention Mycobacterium vaccae (SRL172) as a nonspecific immunostimulant and as an adjuvant to whole tumour cell of MAT-LyLu tumours and the survival benefit was equivalent to that provided when the adjuvant was vaccination in the rat model of prostate cancer. Materials and methods SRL172 was used as a vaccine live-attenuated BCG. SRL172 alone did not reduce tumour take or tumour growth in this model and in the prevention and treatment of subcutaneous tumours in rats. Prevention experiments were conduc-neither strategy was eCective in delaying the growth of established MAT-LyLu tumours. In the Lobund-ted using subcutaneous MAT-LyLu tumours in Copenhagen rats, comparing vaccination with Wistar rat vaccination with autologous whole tumour cells and SRL172 significantly delayed the growth of SRL172 alone, SRL172 plus autologous cells, and bacille Calmette-Guèrin (BCG) plus autologous cells established tumours. Conclusion Mycobacterium vaccae deserves further evalu-before tumour implantation. Treatment experiments were conducted using subcutaneous MAT-LyLu ation as an adjuvant to whole tumour cell vaccination in a phase I clinical trial in patients with prostate tumours in the Copenhagen rat and subcutaneous PAIII tumours in the Lobund-Wistar rat. Tumours cancer. Keywords Prostate cancer, immunotherapy, Myco-were induced by subcutaneous injection with tumour cells. Animals were then vaccinated with autologous bacterium vaccae, vaccine, rat model cells, autologous cells plus SRL172, or SRL172 alone. or by the co-injection of adjuvant [5]. In animal models