Cancer and infectious diseases share a complex relationship, where chronic infections can significantly increase the risk of certain cancers. For example, human papillomavirus (HPV) is a well-known cause of cervical cancer, while persistent infections with hepatitis B and C are associated with liver cancer development. These infections can trigger genetic changes that promote cancerous growth. Additionally, cancer treatments, particularly chemotherapy and immunotherapy, can weaken the immune system, leaving patients more vulnerable to new infections. Ongoing research aims to uncover the mechanisms by which infections contribute to cancer development and progression. The development of preventive vaccines, like the HPV vaccine, and therapies that boost the immune system are key areas of focus, offering new hope in reducing the cancer burden linked to infectious diseases.