Known medically as a malignant neoplasm, cancer is a broad group of various diseases, all involving unregulated cell growth. In cancer, cells divide and grow uncontrollably, forming malignant tumors, which invade to nearby parts of the body. A tumor is an abnormal mass of tissue and is a classic sign of inflammation. There are dozens of different types of tumors. Their names usually reflect the kind of tissue they arise in, and may also tell you something about their shape or how they grow. Diagnosis depends on the type and location of the tumor. Tumor marker tests and imaging may be used; some tumors can be seen (for example, tumors on the exterior of the skin) or felt (palpated with the hands). Although the causes of various cancers are still unknown but for some cancers, their causes may include drinking excess alcohol, obesity, viruses, radiation, chemicals such as benzene, genetic problems, excessive exposure to sunlight and even environmental toxins like aflatoxins and some poisonous mushrooms.
Not all tumors are cancerous. Benign tumors do not grow uncontrollably, do not invade neighboring tissues, and do not spread throughout the blood. Treatment is also specific to the location and type of the tumor. Benign tumors can sometimes simply be ignored, or they may be reduced in size or removed entirely via surgery. However, malignant tumors or simply cancer may also spread to more distant parts of the body through the lymphatic system or bloodstream. For cancerous tumors, options include chemotherapy, radiation, and surgery.
Although cancers can be cured to some extent but the latest researches have shown that the lymphatic system plays a role in the spreading of the tumor and by using patient’s own immune system the tumors escape detection. The antigens which are present on the surface of the tumor cells help them to become recognizable to the immune system of the host. In spite of this cancer vaccines today do not have much success in curing tumors because these tumors evade their detection by the immune cells through various mechanisms which are still a mystery. However, it can be said the lymph vessels which surround a tumor prevent the attack of immune cells (T-cells) by either deleting them or making them exhausted functionally till the time they manage to reach their destination. Hence, if the efficacy of the existing cancer vaccines is to be augmented then it is necessary that the lymph vessels which surround the tumor should be targeted first.