A bone tumor caused by the spread of cancer of some distant organ or tissue, to any bone, is called as Bone Metastasis. It is also known as Bone Secondary, Skeletal Metastasis or simply as ‘Bone or Skeletal mets’. They are often multiple at presentation.
Cancer affecting the bone is of two distinct types:
Absolutely. In-fact‚ bone‚ along with lymph nodes‚ lung and liver‚ are the four commonest sites for metastasis of all cancers. Of these‚ it is the bone metastases that cause the maximum discomfort and disability to the patient. Most causes of cancer related pain is due to Bone Metastasis.
Cancer can spread to any bone in the entire body. However‚ they most commonly affect the axial skeleton (skull‚ spine‚ sacrum and ribs) and the proximal large bones (femur‚ humerus and pelvis). Metastasis is rare in the bones distal to the elbow and the knee.
Any patient with cancer is at a risk of developing Bone Metastasis. Even a person with a history of completely treated cancer and who is now apparently cancer free‚ runs the risk of developing Bone Metastasis‚ especially in the early years following the treatment. Certain cancers like those originating in lung‚ breast‚ prostate‚ thyroid and kidney show an increased tendency for Bone Metastasis.
Any patient with cancer is at a risk of developing Bone Metastasis. In-fact‚ even a person with a history of completely treated cancer‚ and who is apparently cancer free at present‚ also remains at a risk of developing metastasis in the future‚ which among other sites‚ could manifest in the bones. This risk is highest in the immediate years following the completion of treatment‚ and falls subsequently. Some cancers have a higher incidence of metastasizing to the bone as compared to others. Cancers that most often metastasize to bones are those from the lung‚ prostate‚ breast‚ thyroid and kidney.
In many cases‚ detection of Bone Metastasis may be the first indication of cancer in the body‚ i.e. to say‚ in many patients‚ Bone Metastasis may be found without a present or past history of cancer. These patients may realize that they have cancer‚ only after the detection of the Bone Metastasis. The primary source cancer may then be found on a thorough investigation of the patient. The biopsy of the bone lesion often gives strong clues about the possible source of the cancer‚ i.e. which organ/tissue the cancer has originated from. It is logical to conclude that any patient with a higher risk of cancer (e.g. smokers‚ tobacco users‚ etc.) also have a higher risk of Bone Metastasis‚ as Bone Metastasis is a consequence of cancer. Other than the increased risk of Bone Metastasis due to the particular type of cancer (e.g., lung, prostate‚ breast‚ thyroid and kidney cancers)‚ in a known case of cancer‚ some of the other risk factors for Bone Metastasis are‚ a larger disease‚ existing metastasis in other tissues (e.g. in lungs‚ liver‚ lymph nodes‚ etc.)‚ higher grade of disease‚ etc.
Bone Metastasis can cause a number of problems. Some of them are:
Bone Metastasis can cause a number of problems. The most important of them are:
There are several investigations which can help in the detection/diagnosis of Bone Metastases. Some of the important ones are as follows:
There are several investigations which can contribute in the detection/diagnosis of Bone Metastases. Some of the important ones are as follows:
Biopsy is a minor surgical procedure in which a small piece of the tumor tissue is sampled and sent for evaluation to a pathologist‚ who examines it under a microscope to establish its exact histological identity/name (diagnosis). The pathologist can find out whether it is Primary or Secondary Bone Cancer. In case of Secondary Bone Cancer‚ the pathologist can often identify the source of the cancer (i.e. in which distant organ‚ the cancer originated from)‚ which helps in localizing the primary source cancer and thus‚ in initiating effective treatment.
Biopsy is a minor surgical procedure where a small piece of the tumor tissue is sampled and sent to the laboratory for evaluation by a pathologist. The pathologist‚ after processing the tissue sample‚ examines thin slices of it under a microscope to identify whether it is cancerous tissue and if so, what type of cancer it is‚ i.e. its exact histological identity/name (diagnosis). The pathologist can find out whether it is Primary or Secondary Bone Cancer. In case of Secondary Bone Cancer, the pathologist can often identify the source of the cancer (i.e. in which distant organ‚ the cancer originated from)‚ which helps in localizing the primary source cancer‚ and thus in initiating effective treatment.
As a general rule‚ biopsy of any skeletal tumor should be planned and executed as for a primary malignant bone tumor. This is especially true when the bone lesion is solitary‚ i.e. when only one bone tumor is detected after a complete work-up of the patient. This is because, if it turns out to be a primary malignant bone tumor (Sarcoma)‚ the biopsy scar and track have to be included in the surgical excision (To know more about this‚ see the section on Malignant Bone Tumors.). A patient may present with bone tumor in various possible scenarios‚ e.g.:
The diagnostic and therapeutic approach to any patient with suspicious bone lesion/s depends on the consideration of these large numbers of variables and their complex interactions. It is quite possible that a biopsy is not needed in some situations. Thus‚ a decision for a biopsy‚ and when needed‚ the procedure itself‚ is best left to a surgeon with experience in bone tumor treatment. A badly done biopsy can affect the future treatment of the bone disease‚ especially if it turns out to be a primary malignant bone tumor.
Several biopsy techniques are available‚ including Fine Needle Aspiration Biopsy‚ Core Needle Biopsy‚ Incisional Biopsy‚ Excisional Biopsy‚ etc. Biopsy for bone tumors is generally done as a small open surgery (Open Biopsy)‚ or with the help of special biopsy needles (Core Needle Biopsy). Between the two‚ Core Needle Biopsy is generally the preferred method for doing a biopsy as it is a simple‚ reliable‚ minimally invasive‚ safe and quick procedure. The correct method for your situation is best decided by your doctor.
Core Needle Biopsy in skilled hands‚ offers significant advantages over Open Biopsy and therefore‚ it is the preferred method for obtaining tumor tissue samples.
The goal of a biopsy procedure is to obtain a sample of tumor tissue so that it can be studied by the pathologist to identify the exact nature of the disease and establish its identity (diagnosis)‚ as treatment of any tumor depends on its diagnosis. Generally‚ it is possible to obtain a larger quantity of tissue sample (which makes it easier for the pathologist to process and study the material) through an Open Biopsy. However‚ the material obtained by Core Needle Biopsy‚ in most cases‚ is adequate for a skilled pathologist. In many other ways‚ the advantages and benefits offered by a CNB are superior to that of an OB.
As mentioned in the above paragraph; CNB is a simple, reliable, minimally-invasive, safe and quick procedure. To see a table comparing CNB with OB, see the section on Malignant Bone Tumors. This table makes it quite obvious that Core Needle Biopsy in skilled hands, offers significant advantages over Open Biopsy and therefore, it is the preferred method for obtaining tumor tissue samples. Nevertheless, there may be some situations where an open biopsy procedure could be the more suitable option.
Bone Metastasis is different from Primary Bone Cancer. The treatment strategy‚ treatment options‚ treatment goals‚ prognosis‚ etc. are different for Primary and Secondary Bone Cancers. Moreover‚ the behavior of the Bone Metastases and their response to treatment depends on, which cancer caused the metastasis. Metastatic cancer is named by associating it with the identity of the primary source cancer. Although the local treatment for Bone Metastases may be similar‚ their specific systemic treatment depends on knowing the primary cancer causing the metastasis. It is therefore‚ important to identify the primary source cancer responsible for the metastasis.
Bone Metastasis is different from Primary Bone Cancer. Unlike Primary Bone Cancer‚ where the cancer arises from the bone tissue itself‚ in Secondary Bone Cancer‚ the tumor forms in the bone following an implantation of cancer cells from a cancer of some distant organ/tissue that has reached the bone through the circulatory system. It is important to understand that the tissue of the metastatic focus in the bone is identical to the tissue of the primary cancer. This means that a lung cancer which has spread to the bone‚ under the pathologist’s microscope‚ looks similar to the lung cancer from which it has originated. This resemblance does not end with just the appearance; they resemble each other physiologically too, and therefore‚ in their nature and behavior. Metastatic cancer is named by associating it with the identity of the primary source cancer. The bone cancer in the above example is called as ‘Bone Metastasis of lung cancer’. The treatment strategy‚ treatment options‚ treatment goals‚ prognosis‚ etc. are different for Primary and Secondary Bone Cancers. Moreover‚ the behavior of the Bone Metastases and their response to treatment depends on‚ which cancer caused the metastasis. Although the local treatment for Bone Metastases may be similar‚ their specific systemic treatment depends on knowing the primary cancer that caused the metastasis. It is therefore‚ important to identify the primary source cancer responsible for the metastasis.
Bone Metastasis basically means that the patient has some cancer in the body which has spread to the bone. So‚ there is no concept like curing a Bone Metastasis‚ as it represents just one part of the cancer affecting the person. However‚ it can be treated. This can offer serious benefits in terms of survival and quality of life. The outcome of treatment depends on various factors like the type of cancer‚ the number of metastasis‚ etc.
Bone Metastasis basically means that the patient has some cancer in the body which has spread to the bone. So‚ there is no concept like curing a Bone Metastasis‚ as it represents just one part of the cancer affecting the person. However‚ it can be treated. This treatment forms a part of the treatment of the primary cancer which has spread to the bone. The goal of treatment of Bone Metastases is to arrest their growth and to prevent any complications due to them‚ alleviate any symptoms caused by them‚ or treat any complications that might have occurred. This can offer serious benefits in terms of survival and quality of life. Effective treatment may add years to the life of some patients‚ and rare cases have been reported of patients being cured of their cancer‚ despite having Bone Metastasis. The outcome of treatment depends on various factors like the type of cancer‚ the number of metastasis‚ etc.
The most important treatment for any metastasis is the effective treatment of the primary cancer with systemic medication‚ which may be in the form of chemotherapy‚ hormone therapy‚ systemic radiotherapy‚ etc. In addition to the cancer treatment‚ there are a variety of treatment options available for specific treatment of the Bone Metastasis. Targeted treatment of specific Bone Metastasis is usually done only when they are symptomatic‚ have caused complications‚ or show signs suggestive of an impending complication. This may involve the use of radiotherapy‚ surgery‚ radiofrequency ablation‚ etc. Often more than one treatment modality may be employed.
The most important treatment for any metastasis is the effective treatment of the primary cancer with systemic medication (medication which is injected or ingested and therefore reaches all the tissues of the body through the blood).This may be in the form of chemotherapy‚ hormone therapy in hormone sensitive cancers (e.g. breast cancer‚ prostate cancer‚ etc.)‚ systemic radiotherapy in cancers where it is useful (e.g. radio-iodine treatment in thyroid cancer)‚ etc. In addition to the cancer treatment‚ there are a variety of treatment options available for specific treatment of the Bone Metastasis. Local treatment of Bone Metastasis is usually done only when they are symptomatic‚ have caused complications‚ or show signs suggestive of an impending complication. Often more than one treatment modality may be employed. The following are some of the important treatment modalities that are useful in the management of Bone Metastasis.
There are, however‚ a few situations where surgery is the best way to treat Bone Metastasis: