Brain Cancer
Brain cancers are a rare and common type of cancer of the brain. In Europe, it is one of the 13 most frequent types of cancer, according to data published in European Medicine. The World Health Organization states that more than 25,000 people around the world die each year from this type of cancer. Approximately 5% of all new brain cancers are meningiomas (non- malignant tumors), and 1.4% are gliomas, which form their symptoms within the cerebrum.
The main types of Brain cancers
Meningioma: These are low-grade tumor, which usually present themselves before the patient starts treatment. They usually spread through nerve pathways that transmit messages between the brain and the body. This makes them very difficult to find and treat. It may even be possible for they to metastasize to other parts of the body. Meningitis: Malignancy spreads with nerve fibres and leads to a loss of sensation. Tumors may also grow into vital centers on the nervous system or even affect blood vessels and organs. Gliomas: According to WHO classification, gliomas are low- grade tumors, which can be found in the cerebrum or subarachines, and are often localized into the cerebellum. Other forms of “gliomatosis” include pleocytomas, astrocytic sarcomas (astrocytic ependymomas), secondary tumours from other malignancies (e.g., lymphoma, leukemia, etc.), or lymphomas originating from an immunological background (e.g., leukaemia or sarcoidosis). Metastatic tumours: Some tumours grow and cause serious problems from there. Tumors can expand in the bone and have the potential to infiltrate the blood with metastasis, or metastasize to lymph nodes and the central nervous system
What we should look out for
Tumors growing directly into the normal brain structures like nerve paths and the cerebellum are called solid tumours, whereas tumours that grow to other parts of the body (such as osteomyelosarcomas) may also be referred to as soft tumours. Solid tumours can move freely within the skull and are less likely to remain localized.
Tumors with fast growth, rapid enlargement, and a tendency to invade the cerebrum and/or bone are classified as primary tumour types, while tumours that keep the size constant over time, regardless of their location, are secondary tumour types. A patient with a glioma can either show a single area of growth (either fixed or growing, depending on the tumour) or a multiple mass (either fixed or expanding, depending on where and how the tumour grows). Primary tumours are easier to diagnose than secondary tumours by standard diagnostic procedures and are often treated early and effectively. Secondary tumour types require early diagnosis and proper therapy. Tumors with low growth rate are best treated less aggressively compared with tumours with fast growth and high growth rate.
Mesothelioma
Mesothelioma is a rare, rapidly developing disease, which arises in the lining between the internal lining and connective tissue, which consists of epithelial cells (mucosal and supporting), muscle-like cells (myoid, smooth muscle), and immune cells. Mesothelioma usually occurs as a result of injury from exposure to environmental chemicals in the diet (especially to animal feed), or exposure of these chemicals to food via contact with our skin. There are some cases of mesothelioma arising from infections such as measles, rubella, cytomegalovirus, H1N1, etc. It can be associated with any kind of malignancy, including brain tumours. The risk factors of this disease are age, sex, genetic susceptibility, and exposure to certain chemical substances of the environment. The course of the disease varies considerably in each individual, but generally follows a cyclical pattern. Most commonly, patients develop multiple tumours in the abdomen. With the current understanding of genetics and the epidemiology of this disease, treatments have improved substantially. Currently, two drugs to treat this disease are available: imatinib (TK inhibitors) and exogenous interleukin-2 (IL-2) by injection (injection therapy). If necessary, immunotherapy can be used as well. Imatinib can be used to treat patients who have been diagnosed with tumour progression, but not those with stable tumour progression as at the moment. Exogenous IL-2 can also be used as an adjuvant therapy, though it must be administered in a way that does not lead to systemic toxicity.
Clinical features of mesothelioma
In both adults and children, mesothelioma is the most prevalent malignancy of the brain. It accounts for only 2–5 percent of all brain cancers and less than 10% of newly diagnosed malignancies (World Health Organisation: 8). Although mesothelioma has no known therapeutic target, its prevalence increases as new pathophysiological processes are identified. Several mechanisms may contribute to this phenomenon, including immune effects through cytokines and activation of signalling receptors, stimulation of growth pathways, involvement with inflammatory processes, and resistance to radiation and chemotherapy.
Mesothelioma accounts for approximately 5% of all cancers of the central nervous system (8) and 15% of all cancers found in adults (9). About 80 percent of all diagnoses in the U.S., 80 percent worldwide, and about 50 percent in Latin America are made via the biologic tumour markers found in tumour specimens (World Health Organisation: 13). Of the 100 most frequent clinical malignancies of childhood, 55% are caused by congenital mutations of genes associated with the receptor tyrosine kinase (RTK) and 44% by tumours associated with RTKs are monogenic (World Health Organisation: 14). However, the main causes of malignancies in adulthood remain unknown. In adult males, non-monogenesis (i.e., both hereditary and acquired) accounts for nearly 90% of malignancies, and monogenesis accounts for all remaining cancers (World Health Organisation: 14; 11).
The median age at which a person gets diagnosed with mesothelioma is 65 years old (World Health Organisation: 12). Males more than females have similar tumour rates, though women have significantly higher incidence than did males. Male sex has not been associated with differences in survival among different subtypes. Patients with mesothelioma generally have smaller tumours
Prevention
Mesothelioma is associated with various environmental agents and can be influenced by many genes. Since its pathophysiology remains unclear, prevention strategies are being developed based on the biological changes observed when tumour development occurs or during treatments. Two such methods are immunodetection and detection of circulating cytokines (such as cytokines that bind chemokines).
The use of radiopharmaceuticals and radionuclides in the field of medicine can offer a new strategy to detect tumour lesions in a subject without the need for invasive tumour imaging. As radiopharmaceuticals that emit radioisotopes (such as 18F-labelled palginic acid) have proved effective in the detection of tumour deposits in the brain (Lambrecht et al. 2007), the use of functional magnetic resonance scanning (fMRI) and functional near-infrared spectroscopy (fNIRS) could offer new possibilities for the clinical detection of tumour deposits. The combination of fMRI with tomosynthesis (injection of positron emission tomography (PET)) could provide additional imaging modalities for the detection of tumour deposits within the CNS. To date, however, fMRI and PET could not be used as effective methods for the detection of tumour deposits within the brain.
Immunosuppressive drugs are currently being tested to reduce the occurrence of tumour deposits in the brain. One such agent is rituximab, which binds the CD47 receptor on the surface of T cells, thereby inhibiting the interaction of the CD47 complex with signalling proteins (such as transcriptional factor receptor phosphodiesterase-protein (cCR PEP)), reducing the recruitment of T cells to sites of tumour deposits and reducing their activity. Another immunoactive agent is imatinib, which acts as a potent anti-angiogenic and tyrosine kinase inhibitor (TKI) and inhibitors of cepidine small molecule receptor (CSR)-binding proteins (CSRBP). Both of these drugs have the potential to act as anti-angiogenesis agents (World Health Organisation: 13).
However, although each approach might prove beneficial, there is currently no clear evidence to support the efficacy or safety of these approaches specifically, and the benefits of using immunosuppressive agents in terms of reducing the adverse effects of immunotherapy have yet to be proven.
Other than vaccines and radiation therapy, treatments include surgery, radiopharmaceuticals, targeted therapies, cytotherapy, chemotherapy, anti-angiogenesis drugs, targeted radiosurgery, etc. Surgery is preferred over other forms of treatment since a tumour has the possibility to metastasize to other parts of the body, and radiopharmaceuticals might not help in avoiding tumour progression. Radionuclides are thought to be limited in that they cannot reach tumour deposits deep inside the brain, and thus they cannot be used completely.
Another major problem to be considered is that most patients with mesothelioma are older adults. Many of them are young adults who may not be able to undergo a complete transition from the initial stage of tumour growth and therefore do not respond well to treatments. Radiation therapy (such as stereotactic body
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