Kidney cancer: symptoms, signs, treatment, stages, the prognosis
Malignant tumors can rightly be considered the scourge of modern mankind. The incidence of different types is growing steadily, and the mortality rate is still high, despite the successes of scientists in the development of modern and effective ways of dealing with the disease. If these kinds of tumors, as cancer of the stomach, lung, breast or prostate are fairly common and familiar to many people, then kidney cancer heard not every one of us, since this type of neoplasia is relatively rare.
Kidney cancer though not referred to frequently occurring malignant tumors of the person, however, in recent years there has been an increase in the number of patients with this type of tumor. Registered in the world annually about 250 thousand new cases of the disease.
The prognosis of kidney cancer is relatively favorable, provided to detect tumors at an early stage, yet mortality remains high, reaching 40%.
In men, the disease ranks eighth among all detected tumors and women – eleventh, while the risk of disease among the male population is higher by about two times.
Among patients prevail elderly people aged 60 – 70 years. Perhaps this is due to the increase in risk of cancer overall in this age category.
Until now, scientists could not reliably determine the exact factors leading to the development of kidney tumors, but despite this, they were able to achieve good results in the treatment of cancer.
Causes of kidney cancer
Today, we know a great number of carcinogens, their adverse effect is proven, so the majority of tumours are accurately known. We all know that Smoking is with high probability leads to lung cancer, UV light to melanoma, human papilloma virus triggers cervical cancer, but what causes kidney cancer? To accurately answer this question scientists have been unable.
Despite numerous studies, to reliably determine the carcinogenic factors for cancer of the kidney is not yet possible, however, assumes the role of some external causes and pathological conditions of the possibility of development of malignant neoplasms.
Among the risk factors of kidney cancer include:
- Gender and age;
- Arterial hypertension;
- Diabetes mellitus;
- The presence of other renal disease;
- Professional factors;
As mentioned above, kidney cancer is diagnosed much more often in men than in women. The reason for this difference is not entirely clear, but perhaps the role of higher probability of harmful production factors and the prevalence of Smoking among the male population.
Older age also largely contributes to the risk of tumor development, not only due to the long contact time of unfavorable external factors and the emergence of comorbidities, but also due to the accumulation of spontaneous genetic mutations, one of which can give rise to cancer cells.
Excess weight increases the probability of kidney cancer by about 20%. The exact mechanism of its effect remains unclear, but assumed the role of hormonal changes, the accumulation of large amounts of estrogen (female hormone) in fatty tissue that have a carcinogenic effect.
In hypertensive patients the likelihood of developing cancer is higher by 15-20%. Possible negative impact is not hypertension per se, but a long and systematic receiving of antihypertensive drugs.
Smoking is considered one of the most powerful carcinogens. The risk of kidney cancer in smokers is approximately one and a half times higher than in non-smokers, and refusal of the addiction, reduces the risk of tumors.
Harmful conditions of work, involving contact with oil, dyes and pollutants produced in the manufacture of rubber, paper, textiles may also cause of kidney cancer.
The medication may cause cancer. Thus, the systematic use of diuretics, the risk of a malignant tumor is increased by about a third. It is believed that some analgesics, antibiotics, and other drugs, the metabolites of which are excreted in the urine from the body, also increase the risk of cancer.
Among the diseases of the kidneys, which contribute to the development of cancer, we can distinguish chronic renal failure in terminal stage. Perhaps this is due to atrophy and sclerosis (proliferation of connective tissue), leading to hypoxia and cell damage. Such frequent changes, as the presence of stones in the kidney, single cysts on the background of violations of urodynamics does not promote the growth of malignant tumors.
The question of the influence of diabetes continues to be discussed. According to various surveys, the kidney cancer patients with diabetes more common, but because such patients in most cases have hypertension with obesity, to establish the degree of influence of each of these diseases in isolation is difficult.
It has been suggested that diet plays an important role in carcinogenesis. Eating large amounts of animal fats, fried meat increases risk of cancer in General and kidney cancer in particular, due to the ingestion of various kinds of carcinogenic substances, which act not only on the mucosa of the gastrointestinal tract, but, filtering the urine, can cause damage to the tubular epithelium of the kidneys.
The role of genetic mutations in relation to renal cell cancer are actively studied by scientists of different countries, however, an accurate marker of development of neoplasia to date not been established. Despite this, the presence of such patients among close relatives (especially siblings) is considered a risk factor for the disease.
As you can see, most of these potential causes of cancer are of a General nature, having a negative impact on the whole body, but still need to take them into account and as a probable carcinogenic factors in relation to risk of tumours of the kidneys.
Varieties and sources of growth of malignant tumors of the kidney
As you know, the kidneys are paired organs located in the retroperitoneal space of the lumbar region. The main functions are: urine formation and removal of different metabolites and toxic products that enter from outside (drugs, for example), maintenance of normal blood pressure, secretion of hormones, and is also involved in hematopoiesis.
Microscopically the kidney is constructed from a variety of vascular glomeruli at the exit of blood plasma from which the formation of the so-called primary urine. In the system of tubules, starting from the cavity of the glomerular capsule primary urine is released from glucose, trace elements and other necessary body components, and the formation of a secondary urine containing only products of nitrogen metabolism and water subject to removal. So the urine gets into the renal calyx, then the pelvis, the urethra moves into the bladder and removed from the body.
Source of kidney cancer may be the epithelium of the convoluted tubules, collecting duct (renal cell cancer) or lining of the cups and pelvis, transitional epithelium presents, so here cancer is called transitional cell.
Classification of kidney cancer involves the allocation of different histological types based on the presence of features of the microscopic structure of the tumor. Medical oncologists widely used is the TNM system, where T characterizes the features of the primary tumor, N – the nature of the changes in regional lymph nodes, and M indicates the presence or absence of distant metastases.
Morphological variants of kidney cancer:
- Clear cell kidney cancer;
- Chromophilic (papillary cancer);
- Cancer collecting duct.
Over 90% of all diagnosed epithelial renal tumors is clear cell variant, which is sometimes called gipernefroidnyi kidney cancer. This kind of cancer grows as a node, pushing the surrounding tissue and sometimes reaching considerable size. In the early stages of development the tumor is a kind of capsule, its bounding from the surrounding tissue, which growth disappears. The presence of such boundaries distinguish this species from other cancer histological variants exhibiting still in the early stages of its development the tendency to infiltrative growth, penetrating and damaging the kidney parenchyma.
In addition to the TNM system and histological classification, it was proposed that the allocation of stages of kidney cancer (Robson, 1969), which is popular among physicians in the United States. According to this classification:
Metastasis of kidney cancer occur by lymphogenous and hematogenous. Upon confirmation of the diagnosis of malignant tumors of the kidney about a quarter of patients already have metastases, and the most frequent localization – the lungs, bones, liver, lymph nodes, etc.
Metastatic process and for tumors in the kidney have some peculiarities, namely, the possibility of regression of metastases and stabilization of growth of the primary node with the cessation of tumor dissemination in the absence of treatment. This feature can be traced almost a third of patients and should be considered in the presence of high-risk surgical treatment or assignment of chemotherapy due to concomitant severe pathology, since it is proved that those patients without intensive treatment can live longer.
Symptoms of kidney cancer
Like many other tumors, kidney cancer in the early stages may be asymptomatic or give a mild non-specific signs.
The growth of the tumor node and damage to the parenchyma of the organ, there are quite typical symptoms of kidney cancer:
- Hematuria – presence of blood clots in the urine;
- Palpable education in the abdominal cavity;
Hematuria is manifested by the presence of blood clots in the urine, may appear suddenly and just as suddenly disappear for a while, but later resumed. Its presence is associated with hemorrhage and collapse of the tumor tissue and with damage to the renal parenchyma. With a significant amount of blood loss patients suffer severe anemia and blockage of the ureter with a clot can lead to impaired emptying of the pelvis, the accumulation of urine symptoms of renal colic. Hematuria is one of the most typical signs of kidney cancer.
Palpable education in the abdominal cavity on the left or right side it is possible to detect in the later stages of the disease, especially in thin patients. When the tumor is of considerable size (sometimes vaginal cancer reach the size of a head of an adult) it may palpation through the abdominal wall. It is worth considering that the absence of tumor masses in the presence of other characteristic symptoms do not rule out the possibility of a malignant tumor.
When large amounts of the cancer node, increased lymph nodes affected by metastases, and their compression of the inferior Vena cava have these signs of kidney cancer as swelling of the legs, varicose veins of the spermatic cord and abdominal wall, thrombosis of deep veins of the legs and inferior Vena cava.
Pain syndrome is associated with compression of surrounding tissues, neurovascular bundles, the germination of the tumor mass of renal parenchyma. Most often, patients complain of dull aching pain in the abdomen and lumbar region. Over time the severity of the pain increases and they become permanent. At the closure of the ureter by blood clot, hemorrhage in tumor tissue or the rupture of a cancerous node, you may experience a sharp and very intense pain of renal colic.
Other characteristic manifestations of the disease can mention high blood pressure (secondary hypertension) that is associated with damage to vasculature or release in the blood vasopressor agents renin.
During the secretion of tumor tissue of biologically active substances, there are various metabolic disorders (hypercalcemia, hypoglycemia, fever, etc.). Some patients in the absence of liver metastases finds changes in its parenchyma, up to necrosis, which is manifested by changes in laboratory parameters (increased alkaline phosphatase, bilirubin, decrease the amount of albumin in the blood).
In the presence of metastasis in the bones appear symptoms such as pain and pathological fractures; shortness of breath and hemoptysis occur when lung damage, jaundice – when liver metastases, as progressive neurologic abnormalities are the result of a lesion of the brain. These symptoms indicate a neglect of the process and determines a very poor prognosis.
3 and 4 the stage of the disease distinctly common symptoms – weight loss, weakness, loss of appetite, anemia, prolonged fever. These symptoms add up to a picture of the so-called cancer cachexia, occurs when intoxication by metabolic products of the tumor, the decay and necrosis of tumor sites, while damage to surrounding tissues and organs.
Any clinical features of cancer of the left kidney compared to the right-sided localization of the disease does not show, however, metastasis may differ. So, with the defeat of the right kidney lymphogenic metastases are discovered primarily in the lymph nodes of the region of the portal vein, whereas left-sided cancer is characterized by metastasis to para-aortic (aortic) lymph nodes.
It is worth noting that the children described typical symptoms of kidney cancer practically does not occur, and to suspect the presence of the disease is possible by the presence of tumor masses or suspicions arise when examining about other diseases.
How to detect a tumor?
Diagnosis of kidney tumors in most cases does not cause significant difficulties, but because in the early stages of the disease may be asymptomatic, often detected the tumor is already in advanced stages.
Turning the patient to the doctor, the last to find out the nature of the complaints, the time of their appearance, the presence of any other diseases of the urinary system, as well as propellerom abdomen and lumbar region, measure blood pressure.
The main instrumental diagnostic methods believe:
- Ultrasound examination;
- Computed tomography (CT);
- Intravenous urography;
- A bone scintigraphy, x-ray of lungs at suspicion on presence of metastases.
Ultrasonography is the most accessible and cheapest method of diagnosis that allows to detect space-occupying lesions in the kidney parenchyma and to differentiate them from cysts. The method is harmless and can be used as a screening. The disadvantage of ultrasound is a low informative value in persons with excess body weight.
CT can be considered the main and the most informative method of diagnosis, but its accuracy reaches 95%. CT can be supplemented with intravenous contrast, which increases the diagnostic value of the study.
Excretory urography involves the intravenous administration of contrast material with subsequent x-ray evaluation of the sizes, contours of the kidneys, the condition of the Cup-pelvis-plating system, ureters etc the Method is good because it allows you to assess changes in both the kidneys.
In the presence of the contraindications for urography, patients with chronic renal failure, thrombosis of the inferior Vena cava shows the MRI.
To assess the functional state of the kidneys used radioisotope scanning. The study itself does not give accurate data about the tumor, but allows you to determine kidney function, which is important in the choice of tactics of surgical treatment subsequently.
In addition to these studies, the physician must prescribe the total analysis of blood determination of hemoglobin, erythrocytes, erythrocyte sedimentation rate, and urinalysis for hematuria and the presence of other impurities.
The most accurate method of diagnosis of kidney cancer is needle biopsy under ultrasound control, allows you to take a fragment of tumor tissue for histological analysis. However, in some cases with contraindications, the surgeon first removes the entire tumor, and then is subjected to histological examination.
It is important to remember that going to the doctor allows, usually in a timely manner to establish the diagnosis of cancer and to select an effective treatment strategy.
Treatment of kidney cancer
Treatment of kidney cancer involves the use of the basic approaches to oncological care to patients – surgery, radiation and chemotherapy, and other modern techniques (targeted therapy, radiofrequency ablation).
Time begun treatment in the first stage of the disease allows to achieve 90% patient survival and to avoid possible recurrence and metastasis.
Surgical treatment remains the most effective way of dealing with the disease. Removal of the kidney for cancer is performed with large tumor size and gives good results in patients in the first stage of the disease. For the relatively small size of tumors perhaps the use of breast conserving surgery is resection. It is especially important to preserve at least part of the body in patients having only one kidney.
At small sizes the cancer node is possible to use radiofrequency ablation and cryotherapy, which allows to save the affected kidney.
In advanced cases, for large tumors, surgical treatment can be a component of palliative therapy to reduce pain syndrome.
Before surgery nephrectomy in some cases is carried out of arterial embolization to reduce blood flow in the kidney and thus the sizes of the tumor node.
Active surgical tactics often used in relation to metastasis, if appropriate. Such an approach could provide, if not a cure, the transfer of the disease into a chronic but controllable form.
Chemotherapy for kidney cancer have not found a proper application, as these tumors are practically not sensitive to anticancer drugs. This is due to the fact that the cells of the renal tubules, from which the majority of malignant tumors, is produced by a protein causing multi-drug resistance.
Radiation therapy is often used as a palliative method to reduce pain and improve the health of the patient, but the tumor itself is not very sensitive to such influences.
A special place in the treatment of kidney cancer belongs to the so-called targeted therapy. This modern and highly effective method of treatment was developed in the early XXI century and has been used successfully in many patients. This group of drugs is very expensive, but they are in most countries allocated free of charge, and patients and their families should know.
Malignant tumors are formed by specific proteins and growth factors that promote uncontrolled proliferation and growth of cancer cells, the development of a dense network of blood vessels, and metastasize. Targeted therapy directed at these proteins, and this prevents the growth of cancer. Among the drugs in this group have been successfully used sunitinib, sorafenib, temsirolimus, and others.
The negative side of the use of targeted therapy are side effects such as poor tolerability, and fairly quickly the emerging resistance of tumor cells. In this context, targeted therapy often used in composition of combined treatment with other antitumor agents.
Approximately 30-50% of patients after surgical treatment you may experience a relapse, which is a fairly serious complication, because such tumors are prone to aggressive growth and metastasis. The only way to deal with recurrence is surgical removal in combination with the immunotherapy interferon, however, treatment continues to be debated.
The forecast in the case of kidney cancer is determined by the stage of the disease. In the early stages of the tumor, timely treatment allows to achieve good results, while in advanced cases, the presence of extensive metastasis patients do not live more than a year.
Prognosis after removal of cancer remains often disappointing, and the survival rate is not more than 70%, with about half of the patients have a high risk of local recurrence, often very malignant in its course.
The majority of patients after radical treatment of kidney cancer established a disability group that is associated with the loss of authority and possible violation of their traditional way of life and disability in the future.
Because the exact cause of cancer is still unclear, to prevent it you should try to avoid, at least, possible adverse factors. A healthy way of life, normalization of body weight and blood pressure, absence of abuse of drugs, observance of safety measures when working with hazardous substances will help to maintain health and reduce the likelihood of cancer.