Kidney cancer is one of the most subtle and dangerous tumors that
exist; sometimes the first signs of onset are represented by the presence of a
weight on the left testicle or the presence of blood in the urine or with a pain
that seems a trivial low back pain. We try to understand how to prevent it and
what are the signs to fear. It is generally difficult to find a person with
kidney cancer in the clinic, while it is easier to identify other kidney lesions,
e.g. kidney lithiasis, hydronephrosis, of simple acquired kidney cysts. If,
however, the patient presents haematuria, pain in the lumbar lodge, fever or if
other relatives have been affected by kidney cancer in the family, then it is
necessary to investigate, starting with an abdominal ultrasound.
The kidney tumor affects 8500 people / year in Italy, especially with a 40-year age, with a peak of around 60; it represents about 2-3 percent of all malignant tumors and occurs in the male sex twice as often compared to the female sex, with an incidence of about 16 cases per 100,000 men and about 7 cases per 100,000 women, It is more frequent in urban areas compared to rural areas. In recent decades there has been an increase in new cases of renal tumors, probably due to the improvement of diagnostic means of investigation, which, on the other hand, allow an early identification of the neoplasm and a greater timeliness in the surgical intervention.
The risk factors are:
- cigarette smoke, so abolishing smoking reduces the risk from 16 to 28%
- chronic exposure to some metals: lead, cadmium
- congenital factors such as polycystic kidney; patients with cystic kidney
disease, for example those already undergoing dialysis for a long time, have a
30-fold higher risk of developing the tumor.
- Other renal diseases called into question appear to be tuberous sclerosis
- exposure to drugs and contrast agent, phenacetin and torotrast
- inheritance: First-degree relatives of patients with renal cell carcinoma have
a 4-fold higher risk of developing this tumor compared to the general population.
Exists
- a similar chromosomal alteration in von Hippel-Lindau syndrome (VHL)
characterized by a high incidence of renal cell carcinomas.
- obesity
- diet rich in meat while those diets rich in fiber and vegetables prevent this
cancer.
The classic symptoms of this tumor are represented by three very clear aspects:
hematuria (blood loss with urine), low back pain that is mistaken for low back
pain (sic!) And palpable mass. But it may also be that the disease begins in a
subtle way with problems related to fertility, such as the appearance of
varicocele with the dilation of the spermatic veins or with complex pictures of
fever, secondary anemia, hypercalcemia, with the framework of the so-called "paraneoplastic
syndrome". Renal cell carcinoma can spread directly to nearby tissues and organs,
both lymphatically and by blood. The most frequent sites of metastasis are lymph
nodes, lungs in 55% of cases, liver, bone, kidney versus lateral (11%)
contralateral, brain, spleen, large intestine and skin.
To describe the kidney tumor, its location and extension, as well as the
involvement of other structures or organs, the classification based on the TNM
system or that of Robson, modified, is used.
There is also a classification by gravity stage:
stage I: cancer is limited to the kidney;
stage II: cancer is spread to the adipose tissue surrounding the kidney but has
not passed the capsule that encloses the organ;
stage III: cancer has spread through the main vessels carrying clean blood out
of the kidney or to the lymph nodes around the organ;
stage IV: cancer has spread to nearby organs (intestines, pancreas) or has given
distant metastases (to the lungs, to the brain).
It is implemented with the following instrumental and laboratory investigations.
We begin to suspect it when the so-called "renal group" is altered, that is when
the azotemia, creatinine, sodemia, potassium, calcemia, LDH, creatinine
clearance. they have changed. At this point, after the visit, we proceed with
less invasive investigations such as ultrasound, which is able to discriminate a
solid mass (suspected for neoplasm) from a cystic mass and can be investigated
with the Computed Tomography (Tac), which results fundamental to evaluate the
presence of small masses, and that allows to evaluate the extent of the disease.
Other investigations used for a correct staging of the disease and to evaluate
whether or not distant metastases exist are radiographs of the thorax, bone
Scintigraphy, Urography (radiography of the apparatus
urinary visualized through the administration of contrast medium) and finally
the Magnetic Resonance (Rmn), if associated with the Tac, can provide
three-dimensional images of the neoplastic mass in order to an optimal surgical
planning. Lastly, the agobiopsia tac or echo guided lesions is indicated, a
technique at risk for the possibility of spreading the disease (!!).
The most common type of kidney cancer in adults is the adenocarcinoma that
originates from the cells that line the internal tubules of the organ: it is
found in 90 percent of cases and in a small percentage (2 percent) it can also
be bilateral, ie manifest in both kidneys.
Of this type there are three variants:
the clear cell variant (25 percent),
granulose cells (15 percent)
to sarcomatous cells (10 percent);
mixed forms of these three types.
sarcomas in their various forms, these very rare forms (liposarcomas,
leiomyosarcomas, rhabdomyosarcomas, angiosarcomas, fibrosarcomas) that originate
from different tissues (from the capsule or from the structures surrounding the
kidney).
nefroblastoma or Wilms tumor, of children that may nevertheless also occur in
adults./
It is radical surgery, ie the elimination of the diseased kidney, the most used
solution in case of cancer limited to the organ and to a single kidney. In cases
of bilateral disease the two kidneys will not be removed, but only the diseased
part of the organ will be removed. The kidney tumor that has already given rise
to metastases is treated with chemotherapy even if the results are only partial:
the drugs that have proved most active are vinblastine, CCNU and ifosfamide.
Results and hopes are placed in immunotherapy, ie in cures that activate the
immune system of the patient against cancer: there are experiences and studies
that use interferon alpha, interleukin 2 and LAK cells with different results.
Experimental vaccines are also being studied alongside these therapies
These are treatments aimed at inhibiting angiogenesis, ie the development of blood vessels from which the tumor masses nourishes. Among the targeted molecular therapies currently at an advanced stage of development are: sorafenib, sunitinib and bevacizumab. Sorafenib: is an oral compound able to exert both an effect against angiogenesis and a direct effect on the growth of the tumor cell. To verify the efficacy of sorafenib, following phase II studies that yielded very promising results, the largest phase III study in advanced kidney cancer was planned and implemented. From a non-definitive analysis of this study, in which 903 patients were enrolled (half of whom were treated with the drug and half were treated with placebo), it was found that sorafenib doubled the time from disease progression. The latest results (not yet definitive) indicate that patients treated with sorafenib have a median survival of 19.3 months while the median survival of patients treated with placebo alone was 14.3 months. In all the studies conducted to date with sorafenib, a disease stabilization was found in about 80% of the Sunitinib: it is an oral compound able to exert both an effect against angiogenesis and a direct effect on growth of the tumor cell. Sunitinib was evaluated in two non-comparative phase II studies (ie, without comparison with other drugs or with placebo) conducted on a total of 168 patients with metastatic renal cell carcinoma after treatment with immunotherapies. The overall analysis indicated that 61.3% of patients achieved more or less evident reductions in tumor mass while 29.1% did not have progression of the disease. 50% of patients remained progression free of the disease for a period of 8.2 months. Bevacizumab: is a monoclonal antibody administered by injection that binds and neutralizes the circulating VEGF (one of the growth factors responsible for angiogenesis), is currently being studied in other types of tumors including metastatic renal cell carcinoma. Patients treated with bevacizumab had a prolongation of time to disease progression compared to the group of patients treated with placebo.