When cancer spreads from the first site where it developed on the body to other areas of the body we say that the cancer has metastasized. Certain cancers tend to metastasize in certain ways. For instance, lung cancer, which is one of the most common cancers in America (making up 13% of all cancers diagnosed), has cells that tend to break away from the site of the original tumor and enter the bloodstream and lymph nodes, spreading to other parts of the lung, nearby organs such as the heart, or to the liver, kidneys, brain, and bones.

When secondary tumors form in the bones we call these tumors bone metastases. Since many lung cancers are not diagnosed until they have grown and spread to other parts of the lungs and/or body, metastases are common in lung cancer patients.

Doctors can attack the problem by targeting the primary cancer to shrink the tumor and prevent its spread. At the same time, doctors can use treatment options to attempt to shrink or remove metastasized tumors and thus ease symptoms such as bone pain. When lung cancer spreads to the bone it can cause severe pain and weak bones among other symptoms.

Relieving Symptoms
In order to relive symptoms of bone meatsases, doctors can use systemic (which target cancer all over the body) therapies such as chemotherapy or administer drugs known as bisphosphonates. Doctors may also try local therapies (which target specific areas of cancer, particularly those causing pain or other side effects) such as radiation and surgery. At the same time, doctors usually prescribe some type of pain-killing medication to control pain for patients experiencing discomfort.

Systemic Therapies
These types of therapies enter the bloodstream through an injection or a pill. Once in the bloodstream, they work on destroying cancerous cells wherever they exist in the body. Systemic therapies are therefore generally more effective than local therapies in killing cancerous cells in widespread areas of the body. When they succeed, bone metastases symptoms recede and may disappear entirely for a time, or forever.

 
• Chemotherapy - Patients with bone metastases may receive chemotherapy drugs by injection or by mouth. These drugs can be injected or taken orally, usually in “on-off” cycles over a period of weeks and months. Chemotherapy kills cancer cells, but also kills normal cells at the same time which can cause significant side effects. Chemotherapy can be very effective on some cancers and can help reduce the need for pain medications by reducing the size or spread of metastases.  
• Bisphosphonates - Once used to combat osteoporosis, these drugs are now gaining a reputation for being beneficial in treating bone metastases. Biophosphonates work to slow the activity of osteoclasts, thereby preventing excessive bone loss (reabsorption) and the associated elevation of blood calcium levels. In this process, they ease symptoms, including fracture due to weak, thinning bones, as well as the range of symptoms associated with hypercalcemia. Bisphosphonates may be taken by mouth or given intravenously. Intravenous use is most common, as these drugs are difficult for the digestive system to absorb. Bisphosphonates are proving to be very useful since patients experience few side effects (generally only minimal flu-like symptoms) and only for a short period of time. Lung cancer patients who take bisphosphonates most commonly take Zometa (zoledronic acid).

Local Therapies

Local therapies concentrate on a particular area of the body. The therapy may be concerned with destroying cancer in an area, slowing its growth, or reducing symptoms in the area.

 
• Radiation - High-energy rays or particles can be used to fight cancer by destroying cells or retarding their growth. Radiation is typically delivered by an external beam radiation machine, but some patients will receive what’s known as internal radiation (a small radioactive rod or pellet that is implanted near the cancer’s site) or radiopharmaceuticals (radioactive substances that are injected into a vein). In all of these cases, radiation destroys cancer cells or slows their growth with high-energy rays or particles, by destroying one or both of the DNA strands inside cells. When a cancer has metastasized to bones, radiation is used to relieve symptoms such as pain.  
• Surgery - Most surgeries performed in cases of bone metastases are meant to relieve symptoms such as pain and fractures. They are not intended to remove cancer entirely from the body. Doctors may wish to remove a tumor pressing painfully on a nerve or organ (or one which is pressing dangerously on the spinal cord). Doctors can also use surgery to strengthen weak bones, implanting small metal rods in very weak bones to reduce the chance of fracture or to help already-broken bones heal more successfully.

Pain-Killing Medications

Reducing or relieving pain is an important part of bone metastases treatment. Pain often results when a tumor pushes on bones, nerves, or other organs in the body. Other metastases cause pain in a process that is not fully understood by doctors. Generally as metastases grow and spread, the pain also increases.

Often, pain is controlled through the therapies listed above. If pain persists, doctors may recommend pain-killing drugs. The principal drug type used to treat bone metastases pain is non-steroidal anti-inflammatory agents (NSAIDs), which include aspirin, ibuprofen, naproxen, and prescription drugs. These drugs block the action of prostaglandins, which are the source of most pain in bone metastasis patients. Opioids (such as morphine) may also prove useful in pain management by attaching to receptors in the brain and disrupting or preventing the reception of pain messages in the brain.

The following types of medications are the ones typically used to control pain from bone metastases:

 
• Nonopioids: Acetaminophen and nonsteroidal anti-inflammatory drugs (NSAIDs), such as aspirin and ibuprofen are used to control mild pain.  
• Opioids: Prescription options include morphine, codeine, fentanyl, hydromorphone, and oxycodone.  
• Rapid-Onset Opioids: Rapid-onset opioids are used for those with chronic pain or for patients who have “breakthrough” pain that appears suddenly and needs quick control.  
• Steroids: Medications such as prednisone and dexamethasone can lessen pain which causes swelling.

Side Effects

Depending on the therapy or combination of therapies you receive, side effects vary. Some patients experience mild side effects (easy bruising, trouble sleeping) while others have more intense reactions (intense nausea, chronic constipation, loss of hair). Many side effects can be controlled by changing drugs, dosages, or treatment length. Other medications can help control or prevent side effects such as nausea and vomiting.