Through smoking the gastrin secretions in stomach. Gastrin is secreted by antral G- cell and is involved in the stimulation of secretion of HCL from parietal cells into the gastric lumen. The acid then acts on the antrum which in turn reduces the release of gastrin and thus HCL. Smoking affects this negative feedback mechanism. This in turn increases the circulating gastrin levels. Acute smoking causes thus raises the amount of gastrin which as a tropic effect on the parietal cells which in turn increases the volume of acid in stomach. Smoking affects the mucosal region of stomach. It has the risk of developing lesions such as dysplasia, chronic atrophic gastritis and intestinal metaplasia in the gastric region which can later turn to be malignant. The carcinogens present in tobacco smoke either comes in direct contact or through blood circulation on gastric mucosa and impairs them.
Blood cancer begins in the bone marrow and affects the production and function of blood cells. Stem cells can be found in the bone marrow. These mature and develop and divide into the three types. These are red and white blood cells and platelets. When affected with this, there is interruption to the normal development of blood cells due to the uncontrolled growth of abnormal blood cells. These are cancerous blood cells. They prevent the blood from doing its normal job, which includes fighting off diseases etc. Leukemia is one type of blood cancer which occurs due to the abnormal growth of white blood cells. This inhibits the production of red blood cells and platelets. Lymphoma is another blood cancer that affects the lymphatic system. This affects the immune system. Myeloma is another blood cancer that targets plasma cells. Myeloma prevents normal antibody production and this increases the chances of infection and various diseases. Blood cancers are hereditary.