Methods for the treatment of bone metastases

Bone metastases often appear at the advanced stages of cancer. In countries with poorly developed medicine, such patients are often given up and switched to symptomatic treatment. However, doctors in Germany successfully treat bone metastases using external beam radiation therapy, radionuclide therapy, ablation, high-intensity focused ultrasound, and other methods. The Booking Health specialists talk about how bone metastases are treated abroad and what methods are used in developed countries.

Content

1. What types of cancer metastasize to the bones
2. Consequences of bone metastases
3. Surgical treatment
4. Ablation
5. Radiation therapy for bone metastases
6. HIFU therapy
7. Drug therapy
8. Radionuclide therapy
9. The life expectancy of patients with bone metastases

What types of cancer metastasize to the bones

About a third of all distant metastases are found in bones. In terms of the frequency of involvement in the tumor process, bone tissue ranks third: metastases often develop only in the lungs and liver.

Metastatic bone lesions may occur with any type of cancer. However, the vast majority of them are associated with breast, prostate, and lung cancer.

In breast cancer, bone metastases are detected in 75% of patients with stage 4. This tumor ranks first among all malignancies in terms of the frequency of bone metastases. In metastatic prostate cancer, the spine is affected in 90% of cases. Lung malignant neoplasms spread metastases to bones in 40% of patients.

In kidney cancer, the frequency of bone metastases is 33%, and in thyroid malignant neoplasms – 28%, and with aggressive types of tumors – up to 60%.

Bowel cancer with bone metastases and ovarian cancer with bone metastases are relatively rare. The frequency of bone metastases in these tumors does not exceed 10%.

Consequences of bone metastases

There are three types of bone metastases:

• Osteoblastic – with bone growth, an increase in its density, compression of adjacent structures
• Osteolytic – with bone destruction, increasing the risk of fractures
• Mixed – a combination of two options 

The main consequences of bone metastasis are as follows:

Pain. It torments a person constantly and periodically intensifies.

Bone fractures. They occur due to bone tissue demineralization.

Spinal cord compression. It occurs when metastases appear in the spine. Early symptoms are back or neck pain. Then there is numbness in the legs and abdomen, weakness in the legs, and urinary and fecal incontinence.

High blood calcium levels. Calcium is released from destroyed bones. As a result, the following symptoms develop constipation, muscle pain, drowsiness, thirst, and frequent urination. Renal failure progresses over time.

Surgical treatment

A single bone metastasis that causes pain and risk of complications can be removed surgically. This is the most effective treatment. With complete removal, local tumor recurrence is rare.

Bone resection with the subsequent endoprosthesis is the primary radical (i.e., eliminating metastases) surgery to treat metastatic bone lesions. It is widely used in developed countries. German doctors always prefer organ-preserving interventions, avoiding more uncomplicated but life-threatening mutilation surgery.

With metastatic lesions of the long bones or the pelvis, the surgeon removes a bone fragment from 8 to 25 cm long with the tumor. Since a defect is formed in this area, it is replaced with an "artificial bone." Doctors implant endoprostheses made of titanium alloys, which are not rejected by the body, do not cause inflammatory reactions, and gradually grow into their own bone, forming a single whole with it. Less commonly, an allograft (donor's bone) is used to replace the defect. As a result of such surgical procedures, the pain syndrome in the area of ​​the surgery completely disappears in 95% of patients; in 85% of them, there is a complete restoration of the function of the operated part of the body.

Other surgical procedures: 

• Osteoplasty – the injection of bone cement to fix the bone
• Osteosynthesis – the implantation of fixing structures to stabilize the bone, thereby preventing fracture
• Vertebroplasty – the procedure is used for vertebral fractures; this is a minimally invasive intervention for the injection of bone cement into the area of the damaged vertebra
• Extremity amputation surgery (joint removal) – mutilation surgery that is rarely used in developed countries for the surgical treatment of bone metastases

Osteoplasty, osteosynthesis, and vertebroplasty are not radical (curing) methods of treating cancer metastases in the bones. They only allow for preserving the function of the affected part of the body and avoiding fractures. But these surgical interventions are combined with other methods of treatment aimed at destroying cancer cells: for example, with radiotherapy, various ablation options, and radionuclide therapy.

Ablation

Ablation is a procedure for the destruction of a pathological focus. Its advantage is minimal invasiveness. Through a skin puncture, doctors insert a needle into the center of the tumor and heat it; as a result, the malignant cells die.

Radiofrequency ablation is the most common option. Doctors insert a probe into the tissue of the neoplasm and destroy it. It is a minimally invasive procedure that does not cause significant trauma to the patient. Nonetheless, it is rarely used as the only treatment because it increases the risk of bone fracture. It is usually combined with osteoplasty, another minimally invasive procedure to strengthen the bone with cement. It can also be combined with osteosynthesis.

Microwave ablation is a more advanced technique that can remove larger metastases. It "burns" the surrounding anatomical structures less since the spread of heat does not depend on density, electrical conductivity, and other properties of tissues. The procedure takes less time – on average, 5 minutes. The tissues are heated to a higher temperature. The treatment method is similar: a probe is inserted into the tissue, which heats the tumor from the center to the periphery. By adjusting the exposure time, doctors can destroy metastases of various sizes.

Ablation is often combined with surgery. For example, the doctor can remove a piece of bone with a tumor and then destroy its soft tissue component using radiofrequency ablation.

Find specialized hospital & treatment

Radiation therapy for bone metastases

External beam radiotherapy for metastatic cancer is used for palliative purposes. This treatment method aims to relieve pain and improve the patient's quality of life. The method is effective to one or another degree in almost all patients. Six months after irradiation, 70% of treated patients still do not have severe pain, and 35% have no pain at all.

Additional effects of radiation therapy are as follows:

• Destruction of tumor foci
• Restraining their growth
• Restoration of the normal structure of bone tissue

As a rule, a long course of radiotherapy is not required. The entire course dose is given in 5-6 fractions. Thus, the treatment can be completed in 1 week, and its effect lasts for several months. The treatment of bone metastases abroad involves the use of the latest generation linear accelerators, which direct irradiation to the tumor very accurately. They allow for the safe destruction of bone metastases within a single session.

Local radiation therapy for metastatic cancer does not cure cancer. Nonetheless, it creates good conditions for the use of other methods of therapy, primarily systemic ones, which are aimed at achieving control of the tumor and increasing the patient's life expectancy.

HIFU therapy

HIFU has been approved in Europe for the treatment of bone metastases since 2015. It involves exposing the bones to high-intensity focused ultrasound. The method's main advantage is the absence of invasion since a needle does not need to be inserted into the bone. However, HIFU is used only as a second-line treatment, as an alternative to radiation therapy. It is not considered radical, as ultrasound only eliminates pain, shrinks the metastatic focus, and initiates bone repair. Therefore, HIFU must be combined with other treatments, usually systemic ones, which suppress the development of cancer cells.

The method is not used for bone metastases of the skull and spine. It is often used to suppress bone metastases in the pelvis, ribs, sternum, and shoulder girdle.

Benefits of HIFU therapy: 

• No radiation
• No limit on the number of procedures
• It can be used for any bone lesions: osteoblastic or osteolytic
• It doesn't matter if the patient has received radiotherapy before
• It can be combined with any other methods and can be carried out against the background of chemotherapy

According to some studies, the effectiveness of HIFU therapy in relieving pain reaches 100%. The effect develops within three days. It lasts more than three months, and this time is enough to achieve control of the tumor with the help of medications or other treatment methods.

Drug therapy

For the treatment of patients with bone metastases, not only local but also systemic treatment is essential. It is used primarily for general control of the tumor. The drugs suppress cancer cells in all organs and parts of the body at once. Doctors abroad use not only chemotherapy for bone metastases but also hormonal, targeted, and immunotherapy.

But systemic therapy doesn't work right away. Until a therapeutic result is achieved, complications such as bone fractures may develop. Bone strengthening with osteomodifying agents is required to prevent complications. These drugs include:

• Bisphosphonates
• RANK ligand inhibitors (monoclonal antibodies)

These drugs are given immediately after bone metastases are diagnosed, regardless of whether the patient has symptoms.

Bisphosphonates have been used in medical practice for over 50 years. This class of drugs inhibits bone resorption. They relieve pain, improve bone mineralization and reduce the risk of fractures. In the 21st century, three generations of bisphosphonates are used. They more selectively affect bone metastases, cause self-destruction of cancer cells and block the growth of tumor vessels.

New drugs include RANK ligand blockers. The RANK ligand is the main mediator in the vicious circle of bone destruction in patients with bone metastases. Monoclonal antibodies block this substance and thereby interrupt the progression of bone destruction. They also inhibit the growth of metastases.

The effect of taking these drugs:

• Delayed first bone event by more than eight months
• Reduced risk of bone events by 17%
• Delayed progression of pain by two months
• Lower risk of switching from NSAIDs to narcotic analgesics
• Reduced risk of new bone metastases

Advantages of RANK ligand inhibitors over bisphosphonates:

• They do not damage the kidneys
• They do not accumulate in bones
• Good treatment tolerance (low toxicity)
• Convenient use: one subcutaneous injection every four weeks

The efficacy is equally high in patients with a history of bone events and in those who have not suffered from complications yet.

Find specialized hospital & treatment

Radionuclide therapy

Radionuclide therapy involves the injection of radioactive substances that accumulate in the bones and suppress metastatic foci with radiation. This is a systemic modification of radiotherapy. Its advantage is the affection of all bone metastases at once.

Radionuclide therapy has been used since the 80s of the twentieth century. However, the initial attempts caused a significant number of complications, primarily from the side of the bone marrow. The radiation penetrated the bone and suppressed the hematopoietic function and the production of blood cells. The result was severe anemia, bleeding, and immunodeficiency.

In the past 20 years, radiopharmaceuticals have become more sparing and effective. They provide:

• Selective accumulation in metastatic foci
• Rapid elimination from healthy tissues
• The high energy of radiation allows destroying of metastases quickly
• The minimum path length of particles so as not to damage the bone marrow

For metastatic prostate cancer, doctors in Germany often use Radium-233. It attacks bone metastases with short alpha radiation that spreads only 0.1 mm. It does not penetrate the tubular bones and does not have a pronounced effect on the bone marrow.

Many other radionuclides are used to suppress metastases: 153Sm, 89Sr, 32P, 186Re, 188Re, 117mSn, 177Lu.

The life expectancy of patients with bone metastases

The prognosis for patients with metastatic bone lesions differs depending on the aggressiveness of cancer, the presence of other metastases, and the quality of cancer treatment.

For breast cancer with bone metastases, combination therapy usually works well. Doctors target not only metastatic foci but also treat the disease with systemic methods. They use chemotherapy, hormonal, targeted, and immunotherapy. Therefore, in developed countries, even after detecting bone metastases, the three-year survival rate of patients reaches 51.7%, and the five-year survival rate is 31.4% (Z. Wang et al.). Moreover, these data were obtained on patients treated from 2011 to 2016. Since then, much has changed for the better; new treatment methods have appeared. Medical oncology is evolving, and the treatment outcomes for patients who start therapy today will be much better.

Doctors get good results in the surgical treatment of metastases in the pelvic bones. The overall five-year survival rate of such patients is 33% (R. Tillman et al., 2019). Only 10% of them need repeated surgery.

In the case of lung cancer with bone metastases, the prognosis is worse, but even in these patients, good results can be achieved with a quality selection of hospitals for treatment. In this category of patients, chemotherapy alone is often used. But in this case, the median survival is only six months. Suppose doctors managed to remove the primary tumor and all metastatic foci by surgery. In that case, the five-year survival rate of such patients reaches 10-25%, depending on the number and location of metastases. The best prognosis is achieved in patients whose tumor has not spread to the pleura.

Modern methods of treating bone metastases help relieve pain, prevent fractures, improve quality of life, and create conditions for other systemic cancer therapy conditions. Even stage 4 cancer with bone metastases is not a death sentence if you receive treatment in one of the best hospitals in the world. Although the disease is rarely completely cured, many patients can live 5-7 years or more after detecting metastatic foci.

To receive the best results, you can undergo bone metastases treatment in Germany. The latest techniques are used in this country, including modern options for irradiation, radionuclide methods, modern types of surgical procedures, ablation of neoplasms, and systemic therapy. With the help of the Booking Health service, you can compare the cost of treatment in different hospitals and book treatment at a favorable price. Our experts will help you decide on the choice of a medical center and organize your trip.

Contact Booking Health

Choose treatment abroad and you will for sure get the best results!

Authors: 

The article was edited by medical experts, board certified doctors Dr. Nadezhda Ivanisova and Dr. Vadim Zhiliuk. For the treatment of the conditions referred to in the article, you must consult a doctor; the information in the article is not intended for self-medication!

Sources:

National Library of Medicine

American Cancer Society

National Cancer Institute

Read:

Why Booking Health - questions and answers 

How to make right decision when choosing the clinic and specialist

7 reasons to trust to the rating of clinics on the Booking Health portal

Booking Health quality standards