One of the most feared and common causes of mortality in the world is cancer, which has had a serious impact on people and is still an unsolved problem. Cancer is caused by a variety of reasons, including aberrant gene expression, epigenomic variables, environmental factors like pollution and ongoing radiation exposure, or cells evading cell cycle checkpoints. These factors result in uncontrolled growth and proliferation of cells, and in some cases, metastasis occurs, which is the spread of cancerous cells to other parts of the body (Mills et al., 2022). However, disruption of cellular signaling pathways and the linkage of long-term inflammation are also major factors that may contribute to the development of different malignancies (Nigam et al., 2023). TGF-β1, an inflammatory cytokine, has been linked to cancer development by influencing the function of cell cycle checkpoint proteins, and cell signalling pathways (Deb et al., 2025).

Statistics given by the American Cancer Society show that 20 % of deaths in 2018 were due to cancer. It is estimated to increase even more by the year 2030, affecting 26 million people worldwide and 17 million cancer deaths (Lou et al., 2021). Men show higher cancer mortality rates as compared to women. The most prevalent cancer types are ductal and lobular carcinoma, melanoma, colorectal cancer, bronchogenic carcinoma, urothelial carcinoma, endometrial cancer, leukemia, pancreatic cancer, and liver cancer (“Cancer Statistics,” 2020). There have been plenty of statistical reports proving that cancer is way more harmful disease than we think it is. The most alarming fact is that most cancers are diagnosed at late stages (Łukasiewicz and Fol, 2018).

The conventional therapies and other treatments are available for cancer that have some adverse effects, including cognitive thinking disabilities, blood clots in veins, fatigue, anemia, bruising and bleeding, loss of appetite, etc. Prolonged exposure of healthy cells to chemotherapeutic agents results in increased drug resistance in healthy cells as well, thus conventional chemotherapeutics can be non-specific (Mills et al., 2022, Patyar et al., 2010). To overcome these challenges, plant-derived compound-based anti-cancer research is being conducted in various cancers using both in vitro and in vivo cancer models (Debnath et al., 2024).

Besides the evaluation of the cancer therapy by using different prospects through small molecules(Yukta et al., 2024; J. Zhang et al., 2025) or supramolecular complexes (Bhattacharjee et al., 2024; Maity et al., 2025; Nath et al., 2025) or engineered immune cells(Jang and Park, 2025; D. Zhang et al., 2025), recently, bacterial species including Salmonella spp., Escherichia spp., Pseudomonas spp., Listeria spp., and Lactobacillus spp. based anti-cancer activities are also under investigation after the pioneering work of Dr. William B. Coley, which started in 1891 (McCarthy, 2006). Among all of the methods, using microbes is the most basic, effective, and sadly, forgotten strategy(Łukasiewicz and Fol, 2018). Recent studies and technological breakthroughs have demonstrated this. They can enter and stop the tumor cells' activity (Sieow et al., 2021). This review article is divided into three major sections, the first of which elaborates on conventional cancer therapy, and the second of which discusses how bacterial species-based cancer therapy has gained attention in cancer therapy due to its mechanism. The second section describes the mechanism of FDA-approved drugs and how they may cause toxicity, as well as how bacterial components-based cancer therapy works to overcome this. The final section explores current breakthroughs in cancer therapy based on several bacterial species.