Tumors of the kidney

When an ultrasound shows a renal lesion of cystic type, but with internal irregularities or suspicious septa, the first diagnostic thought should be that of a possible neoplasm. However, ultrasound alone is not enough to confirm the diagnosis; therefore, it is necessary to investigate further with second-level examinations.

The reference investigation is computed tomography (CT) of the abdomen with contrast medium. This examination allows for:

• Precisely define the size and position of the mass;

• Assess whether the tumor has spread beyond the kidney(extrarenal spread);

• Identify the possible presence of enlarged lymph nodes;

• Check for distant metastasis.

In some cases, when CT is not feasible (e.g., due to contrast medium allergy or other contraindications) or when the lesion is particularly complex, magnetic resonance imaging (MRI) may be used. The latter offers detailed images and is an excellent alternative for completing the assessment.

In the diagnostic pathway of renal cancer, percutaneous renal biopsy, performed under ultrasound or CT guidance, may be useful in selected cases.
This procedure, which involves harvesting a small fragment of tissue, is indicated especially when the renal mass has atypical features and does not allow a diagnosis to be made with certainty based on radiological images alone.
Histologic analysis of the specimen makes it possible to clarify the nature of the lesion and more precisely guide treatment choices.

Kidney tissue samples taken by biopsy are sent to the pathology laboratory where they undergo microscopic histologic examination. If the anatomo-pathologist detects tumor cells, he or she will ascertain whether or not it is a malignant tumor.

Indeed, renal masses can be subdivided anatomo-pathologically into benign and malignant tumors.

Benign renal tumors

The most common are:

• papillary adenoma
• fibroma or hamartoma
• angiomyolipoma
• oncocytoma

Malignant renal tumors

Renal cell carcinoma is divided into:

• non-papilliferous, so-called “clear cell”
• papilliferous
• chromophobe
• of the collecting ducts

Conservative surgery (partial nephrectomy)

Conservative surgery, or partial nephrectomy, is now considered the first choice for surgical treatment of localized stage T1 renal cell carcinoma. It is the gold standard especially in cases of small renal masses (tumors < 4 cm, stage T1a).

The goal of this approach is to remove the lesion while preserving as much healthy kidney tissue as possible to maintain good kidney function and reduce the risk of long-term complications.

Conservative surgery is:

• an absolute indication in patients with only one functioning kidney, with already reduced kidney function, or with tumors present in both kidneys;

• the preferred choice even in patients with healthy contralateral kidney, whenever the lesion is technically resectable. In some cases, even larger tumors (over 7 cm) can be successfully treated with this technique.

To precisely define the margins and extent of the mass, the surgeon can use intraoperative ultrasound, which provides real-time images during surgery. In addition, 3D CT image reconstruction technologies, integrated during robotic surgery, are available at the Candiolo Institute, allowing the resection to be planned and guided with very high precision.

Radical nephrectomy

Radical nephrectomy is a surgical procedure that involves the complete removal of the tumor-affected kidney, along with the fascia of Gerota lining it, the adjacent adrenal gland, and a section of the ureter, after tying off the renal artery.

The operation can be performed with different approaches:

• open-air, with a single incision;

• laparoscopic, through small incisions using thin instruments and a camera;

• robot-assisted, which uses robotic systems for greater precision.

Today, laparoscopic radical nephrectomy is the gold standard for patients with stage T1 renal tumors that are not candidates for conservative surgery (when partial removal of the kidney is not technically feasible due to site or growth pattern of the lesion) or stage T2. This approach offers the advantage of faster recovery and less postoperative discomfort, while maintaining the same effectiveness as traditional surgery.

Radiofrequency ablation (RFA) and cryoablation techniques represent minimally invasive options for the treatment of small renal masses. These procedures offer some important advantages, such as lower morbidity (i.e., they cause fewer complications, side effects, or treatment-related problems), the possibility of outpatient treatment in some cases, and the ability to operate even on patients with a high anesthesiological risk.

The main indications for these methods involve renal masses less than 4 cm in size, often incidentally discovered, and located in the cortical portion of the kidney. They are particularly useful in:

• Elderly patients or patients with multiple associated diseases (comorbidities);

• Patients with genetic predisposition to the development of multiple or successive cancers over time;

• Patients with renal tumors in both kidneys;

• patients with only one kidney and at high risk of needing chronic dialysis in case of surgical resection.

Absolute contraindications are the presence of uncorrectable coagulopathies and conditions of severe organic instability, such as septic pictures.

Importantly, the risk of recurrence after ablative treatment is higher than with conservative surgery, which may result in the need for further treatment. However, for some patients these techniques are an effective and less invasive option

In recent years, along with probe ablation techniques, active surveillance has become a viable alternative to surgery in selected patients. This strategy is particularly suitable for small renal masses smaller than 4 cm, which are now often diagnosed randomly, especially in elderly patients with several concomitant diseases. In these patients, surgery may carry significant risks, both in terms of mortality during surgery and postoperative complications. In addition, life expectancy may be less than the time the disease would take to evolve.

It should also be mentioned that a significant proportion of these small kidney lesions-up to 20 percent-turn out to be benign, i.e., noncancerous, after in-depth diagnostic investigations such as biopsy or surgery.

Active surveillance therefore involves close and regular monitoring of the renal mass, with periodic checks by imaging examinations, deferring any treatment to a later stage only if necessary.

Radical nephrectomy-that is, complete removal of the diseased kidney-is the only curative option when the tumor can be removed completely. However, in cases where the disease is advanced and metastases are present, nephrectomy no longer serves a curative purpose but can still play an important role.

In these situations, we talk about cytoreductive nephrectomy, which is an operation aimed at reducing the tumor mass as much as possible, even if it cannot be eliminated completely. This intervention can help improve the effectiveness of subsequent systemic therapies and control symptoms.

Cytoreductive nephrectomy is recommended when it is technically possible and the patient is fit for the procedure, always with the goal of ensuring the best possible quality of life.

In selected cases of metastatic renal cancer, surgery can be used to remove metastases, especially if they are few and located in accessible areas, such as the lungs or liver. This strategy, called metastasectomy, can help improve disease control and, in some patients, prolong survival.

The decision to surgically intervene on metastases is evaluated on a case-by-case basis, considering the amount, site of metastases, general status of the patient, and response to systemic therapies.

Metastasectomy is usually part of a multidisciplinary approach that includes medical therapies such as target therapy or immunotherapy.

Radiation therapy can be used in patients with brain or bone metastases that cannot be surgically removed. In these cases, radiation therapy helps to significantly reduce symptoms, improving quality of life.

The introduction of biologic drugs has revolutionized the treatment of metastatic renal cancer, offering new therapeutic options that have improved the management of the disease.

Today, treatment options for metastatic renal carcinoma include targeted therapies (target therapy) and immunotherapy. Target therapies act on specific molecular mechanisms underlying tumor growth, blocking tumor cell proliferation or disrupting the blood supply that feeds the tumor. Immunotherapy, on the other hand, helps the immune system recognize and fight cancer cells more effectively.

To ensure timely and direct support andreceive prompt answers to concerns and questions, a dedicated helpline is in place at the Candiolo Institute for all patients. Monday through Friday, from 8 a.m. to 5 p.m., you can contact the secretariat of the Oncology Day Hospital at 011.993.3775, reporting the need for urgent consultation.

The patient will be quickly put in touch with their medical specialist for clear answers and immediate support.

The cancer patient is a complex patient who requires multidisciplinary support for the management, not only of his or her pathology, but also of all associated situations.

At the Candiolo Institute, specialists from different disciplines are available at Candiolo for patients who need or request them to offer:

• • nutritional support

• • physiotherapy

• • pain therapy

• • Management of other coexisting conditions.

The Social Service Department of the Candiolo Institute offers information and orientation interviews aimed at patients and their families, to facilitate access to services in the area and to welfare and social security benefits provided by law (disability, benefits for aids and prostheses, work leave, etc.).

The service is available on Wednesdays and Fridays, from 9 a.m. to 1 p.m. Information is available by calling 011.993.3059.

The main goal of follow-up after surgical treatment of renal carcinoma is the early detection of any local recurrence or distant metastasis, so as to intervene early when the patient is still potentially curable.

In patients with metastatic disease, the follow-up program is individualized, whereas for those with localized disease who have received treatment with curative intent, there are standardized protocols. These take into account both the individual risk profile and the effectiveness of the treatment performed.

It is important to remember that in some specific situations, such as after radiofrequency treatments (RFA) or cryoablation, in large tumors (>7 cm) undergoing renal conservative surgery, or in case of positive surgical margins, the risk of local recurrence is higher. In these cases, follow-up will be intensified to ensure closer monitoring.