Renal cell carcinoma – Wikipedia, the free encyclopedia

Renal cell carcinoma (RCC, also known as hypernephroma, Grawitz tumor, renal adenocarcinoma) is a kidney cancer that originates in the lining of the proximal convoluted tubule, a part of the very small tubes in the kidney that transport waste molecules from the blood to the urine. RCC is the most common type of kidney cancer in adults, responsible for approximately 90-95% of cases.[1] Initial treatment is most commonly either partial or complete removal of the affected kidney(s) and remains the mainstay of curative treatment.[2] Where the cancer has not metastasised (spread to other organs) or burrowed deeper into the tissues of the kidney the 5-year survival rate is 65-90%,[3] but this is lowered considerably when the cancer has spread. It is relatively resistant to radiation therapy and chemotherapy, although some cases respond to targeted therapies such as sunitinib, temsirolimus, bevacizumab, interferon alfa and sorafenib which have improved the outlook for RCC.[4]

The body is remarkably good at hiding the symptoms and as a result people with RCC often have advanced disease by the time it is discovered.[5] The initial symptoms of RCC often include: blood in the urine (occurring in 40% of affected persons at the time they first seek medical attention), flank pain (40%), a mass in the abdomen or flank (25%), weight loss (33%), fever (20%), high blood pressure (20%), night sweats and generally feeling unwell.[1] RCC is also associated with a number of paraneoplastic syndromes (PNS) which are conditions caused by either the hormones produced by the tumour or by the body's attack on the tumour and are present in about 20% of those with RCC.[1] These syndromes most commonly affect tissues which have not been invaded by the cancer.[1] The most common PNSs seen in people with RCC are: anaemia (due to an underproduction of the hormone, erythropoietin), high blood calcium levels, polycythaemia (the opposite to anaemia, due to an overproduction of erythropoietin), thrombocytosis (too many platelets in the blood, leading to an increased tendency for blood clots and bleeds) and secondary amyloidosis.[6] When RCC metastasises it most commonly spreads to the lymph nodes, lungs, liver, adrenal glands, brain or bones.[6]

Historically, medical practitioners expected a person to present with three findings. This classic triad[7] is 1: haematuria, which is when there is blood present in the urine, 2: flank pain, which is pain on the side of the body between the hip and ribs, and 3: an abdominal mass, similar to bloating but larger. It is now known that this classic triad of symptoms only occurs in 10-15% of cases, and is usually indicative that the renal cell carcinoma (RCC) in an advanced stage.[7] Today, RCC is often asymptomatic (meaning little to no symptoms) and is generally detected incidentally when a person is being examined for other ailments.[8]

Other signs and symptom may include haematuria;[7] loin pain;[7] abdominal mass;[8]malaise, which is a general feeling of feeling unwell;[8] weight loss and/or loss of appetite;[9]anaemia resulting from depression of erythropoietin;[7]erythrocytosis (increased production of red blood cells) due to increased erythropoietin secretion;[7]varicocele, which is seen in males as an enlargement of the tissue at the testicle (more often the left testicle)[8]hypertension (high blood pressure) resulting from secretion of renin by the tumour;[10]hypercalcemia, which is elevation of calcium levels in the blood;[11] sleep disturbance or night sweats;[9] recurrent fevers;[9] and chronic fatigue.[12]

The greatest risk factors for RCC are lifestyle-related; smoking, obesity and hypertension (high blood pressure) have been estimated to account for up to 50% of cases.[13] Occupational exposure to some chemicals such as asbestos, cadmium, lead, chlorinated solvents, petrochemicals and PAH (polycyclic aromatic hydrocarbon) has been examined by multiple studies with inconclusive results.[14][15][16] Another suspected risk factor is the long term use of non-steroidal anti-inflammatory drugs (NSAIDS).[17]

Finally, studies have found that women who have had a hysterectomy are at more than double the risk of developing RCC than those who have not.[18] The reason for this remains unclear.

Hereditary factors have a minor impact on individual susceptibility with immediate relatives of people with RCC having a two to fourfold increased risk of developing the condition.[19] Other genetically linked conditions also increase the risk of RCC, including hereditary papillary renal carcinoma, hereditary leiomyomatosis, Birt-Hogg-Dube syndrome, hyperparathyroidism-jaw tumor syndrome, familial papillary thyroid carcinoma, von Hippel-Lindau disease[20] and sickle cell disease.[21]

The most significant disease affecting risk however is not genetically linked patients with acquired cystic disease of the kidney requiring dialysis are 30 times greater more likely than the general population to develop RCC.[22]

The tumour arises from the cells of the proximal renal tubular epithelium.[1] It is considered an adenocarcinoma.[6] There are two subtypes: sporadic (that is, non-hereditary) and hereditary.[1] Both such subtypes are associated with mutations in the short-arm of chromosome 3, with the implicated genes being either tumour suppressor genes (VHL and TSC) or oncogenes (like c-Met).[1]

The first steps taken to diagnose this condition are consideration of the signs and symptoms, and a medical history (the detailed medical review of past health state) to evaluate any risk factors. Based on the symptoms presented, a range of biochemical tests (using blood and/or urine samples) may also be considered as part of the screening process to provide sufficient quantitative analysis of any differences in electrolytes, renal and liver function, and blood clotting times.[21] Upon physical examination, palpation of the abdomen may reveal the presence of a mass or an organ enlargement.[23]

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Renal cell carcinoma - Wikipedia, the free encyclopedia