Pathophysiology: Neoplasia and Renal System School of Nursing

1. Cancer Staging Cancer staging describes the severity of a person’s cancer based on the person’s initial tumor, and whether or not the cancer has metastasized (American Cancer Society, 2012, www.cancer.org). Knowledge of the stage is very important in that is can be used to explain prognosis to the patient, and can be used by the doctor and the patient to plan treatment. Staging of cancer is based on knowledge of the way in which cancer progresses in the body. Malignant cells grow and reproduce without any control or order, and they do not die when they should. In most cases the cancer cells will form a mass called a tumor. As the tumor grows it can invade tissues and organs that are close to it. The malignant cells can also break away from the tumor and enter the bloodstream (Lemone, 2004, p. 284). There are five common elements considered in most staging systems: site of the primary tumor, tumor size and number, lymph node involvement, cell type, and the presence or absence of metastasis. A common staging system is called TNM, which stands for Tumor, lymph Nodes, and Metastasis. When staging a number is added to each letter to indicate the size of the primary tumor and the extent of the cancer spread. (Lemone, 2004, p. 284) Infection, immunity and inflammation in cancer patients are all interrelated. They form what could be a triangle with arrows in all directions. Infections cause inflammation, and these inflammatory states lead to environments that foster genomic lesions and tumor initiation. Some types of cancer can damage the immune system, however it is most often the cancer treatment that causes short or long term damage to the immune system. When the body has a decrease in effectiveness of it’s immune system, a patient is more susceptible to an infection, which then again would cause inflammation (American Cancer Society, 2012, http://www.cancer.org). 2. Childhood Cancers There are 12 major types of childhood cancers. Leukemias and cancers of the brain make up about half of newly diagnosed cancers. Hodgkin disease is a cancer of the lymphoid system. While Hodgkin disease has been seen in infants and very young children, it is most common in the teenage years. The exact cause of Hodgkin disease is unknown but epidemiologic studies suggest that there are common factors that may increase the likelihood that a person will develop Hodgkin disease (American Cancer Society, 2012, www.cancer.org). Hodgkin lymphoma is a germinal center, B-cell malignant disorder that affects the reticuloendothelial and lymphatic systems. Disease extension is predictable, is contagious, and can affect other organs and systems. Organs that are predominantly affected include the lungs, bone, bone marrow, liver parenchyma, and, rarely, the central nervous system. Three factors may contribute to the development of Hodgkin disease: viruses, genetics and immune system deficiencies. Although no virus directly causes the disease, the Epstein Barr virus is seen in the tumor tissue 20-30% of patients. Studies have also reported an increased risk of disease in close relatives of patients with Hodgkin disease, especially in siblings. Finally, people with compromised immune systems may be more likely to develop Hodgkin disease. These deficiencies can be environmental, acquired, or could occur in people infected with HIV (Huether, 2008, p. 528-529). Retinoblastoma is a cancer of the eye that affects the retina.. It is the most common primary eye cancer of childhood. In order for retinoblastoma to occur there must be a mutation of the tumor suppressor gene Rb1. A mutation here prevents the Rb1 from making the functional proteins and interferes with its ability to regulate cell division. As a result a neuroblastic tumor develops. RbI mutations are inherited in an autosomal dominant pattern, which means that a single copy of the mutated gene, in each cell, can significantly increase cancer risk. In the majority, these mutations are spontaneous, while in the rest it is hereditary. Children can also have a mutation on the Rb1 gene that does not affect every cell of the body. These children will develop unilateral retinoblastoma (Huether, 2008, p. 232). 3. Acute Renal Failure v. Chronic Kidney Disease Renal, or kidney failure occurs when kidneys fail to adequately remove waste products from the blood. Renal failure results when approximately three fourths of the nephrons of both kidneys cease to function. The two forms of renal failure are acute renal failure (ARF) and chronic kidney disease (CKD). Acute renal failure results from an abrupt decline in renal function, and is usually caused by an ischemic or toxic attack to the kidneys, and is seen within hours or days of the assault. Chronic kidney disease occurs over a period of months or years and it may not present any complications until very little kidney function remains. ARF is often reversible; in most cases CKD is not. (Huether, 2008, p. 799-802). Symptoms of decreased kidney function like electrolyte or fluid imbalances are more likely to occur with ARF. Electrolyte imbalances are seen with serum increases in creatinine, blood urea nitrogen, potassium, phosphate, or with a decrease in calcium. Both ARF and CKD will manifest a urine specific gravity below 1.020, a decrease in GFR, a decrease in platelets, and an increase in eosinophils (Huether, 2008, p. 801). There are three stages of acute renal failure: initiation, maintenance and recovery. Initiation is the time from the actual injury to the actual cell death. Maintenance phase is characterized by further damage to the kidney, and is when the electrolyte imbalances will occur. In the recovery phase, whatever harmed the kidneys has been removed but there is scarring and tissue edema. In phase the kidneys will slowly return to adequate function again (Lemone, 2004, p. 762-764). There are five phases of chronic kidney disease. They are described in terms of the severity (slight, mild, moderate, severe) of the kidney damage and are measured by the glomerular filtration rate (GFR). Chronic kidney disease would occur in people whose GFR is less than 90, progressing through worsening symptoms as the GFR falls. End stage kidney disease, or kidney failure would occur when the GFR is below 15. (Huether, 2008, p. 804). 4. Glomerulonephritis v. Nephrotic Syndrome Glomerulonephritis and nephrotic syndrome are diseases although similar are actually very different as well. Glomerulonephritis and nephrotic syndrome are both kidney disorders in which result from damage to the glomeruli, small blood vessels in the kidneys. When working properly the glomeruli filter waste and excess water from the blood and send it to the bladder as urine (National Kidney Foundation, 2012, http://www.kidney.org/). In glomerulonephritis, inflammation causes damage to the glomerular capillaries and reduces the size of the capillary lumen. The inflammation is usually caused by an infection, such as streptococcal bacteria or tuberculosis, which triggers antibodies to react to fight them off. The antibodies combine with bacterial antigens to form immune complexes, which then become trapped in the glomerulus and activate an inflammatory response in the glomerular basement membrane. This immune response causes damage to the glomerular capillaries and reduces their size. The inflammation prevents filtering of urine, resulting in an accumulation of waste in the blood stream. This leads to a decrease in GFR. The decrease in GFR will lead to renal insufficiency, sodium and fluid retention, which can then lead to edema and oliguria. Glomerulonephritis occurs most frequently in young school age children usually after an infection (Lemone, 2004, p. 747) In nephrotic syndrome, some insult causes damage to the gloemeruler basement that causes increased permeability. This damage causes increased permeability and a loss of substances that would normally prevent proteins from crossing the membrane. This allows protein (in the form of albumin) to leave the blood and be excreted in the urine. Hypoalbuminemia reduces the plasma oncotic pressure and causes a shift of fluid into interstitial spaces, thereby decreasing renal blood flow. Reabsorption of Na occurs which leads to edema. Nephrotic syndrome is seen mostly in toddlers or preschool age children. Nephrotic syndrome generally results from another disorder that damages the kidneys including hepatitis, diabetes, lupus and certain cancers (Lemone, 2004, p. 748).

References American Cancer Society, (2012), Cancer and Inflammation, Retrieved from http://www.cancer.org/Cancer/CancerCauses/OtherCarcinogens/InfectiousAgents/InfectiousAgentsandCancer/infectious-agents-and-cancer-intro American Cancer Society. (2012). Hodgkin Disease. Retrieved from http://www.cancer.org/cancer/hodgkindisease/index American Cancer Society, (2012), Retinoblastoma, Retrieved from http://www.cancer.org/cancer/retinoblastoma/index Huether, S.E & McCance, K.L. (2008). Understanding Pathophysiology. St. Louis, MO: Mosby, Inc. Lemone, P. & Burke, K. (2004). Medical Surgical Nursing : Critical Thinking in Client Care. Upper Saddle River, NJ : Pearson Education, Inc. National Kidney Foundation, (2012), Kidney Diseases. Retrieved from http://www.kidney.org/kidneydisease/.