Bone Cancer: What You Need to Know

Bone cancer is an abnormal growth of cells within the bones, characterised by uncontrolled and unregulated cell division. While it's a rare medical condition, it can have a profound impact on affected individuals. Given the seriousness of this disease, early detection and a comprehensive understanding of its nature are paramount for effective treatment and favourable outcomes. In this blog, we will delve deep into the types, causes, symptoms, and treatment options for bone cancer, shedding light on the various bone cancer stages and the importance of early diagnosis, starting with the most widely asked question.

Is Bone Cancer Curable?

Yes, bone cancer is curable if bone cancer causes or symptoms are detected earlier. It also depends on the stage and type of cancer. Talking of osteosarcoma, the commonest primary bone cancer, if detected in time (before the disease has spread to other parts of the body), the long-term survival rates are up to 65-70%. This means a good percentage of these patients can get rid of this disease if detected early.

Bone Cancer Symptoms

The patient with bone cancer usually has pain in the affected area, the knee being the most common site. The pain may be severe, cause the patient to limp, and even be there when the patient is not walking, e.g., at night. There may also be a swelling of the bone or even a fracture that happens without any significant injury. Because these symptoms are not exclusive to bone cancer, they may be mistakenly diagnosed as injury/infection or some other bone disease. Hence, a high index of suspicion is needed to pick up a cancer of bone early enough. 

Types of Bone Cancer

Bone cancer can be broadly categorised into two types: Primary bone cancer, which originates within the bone, and Secondary bone cancer, which starts in another organ and later metastasises to the bone. It's worth noting that secondary bone cancers are far more prevalent than primary bone cancers.

Primary Bone Cancer

The three predominant forms of primary bone cancer are Osteosarcoma, Ewing Sarcoma, and Chondrosarcoma.

• Osteosarcoma: The most common type of bone cancer arising from cells responsible for new bone tissue formation. Predominantly found in the extremities of large bones, such as the legs and arms, osteosarcoma is most frequently diagnosed in children and adolescents.
• Ewing Sarcoma: Named after the doctor who identified it, Ewing Sarcoma encompasses several tumour types originating from a common cell type. These tumours can manifest in bones or the surrounding soft tissues of the hips, ribs, shoulder blades, or legs.
• Chondrosarcoma: Originates in cartilage, the soft connective tissue facilitating movement between bones and joints. As the body adds calcium to some cartilage, it transforms into bone. Chondrosarcoma primarily affects the bones of the arms, legs, or pelvis and is more prevalent in adults than in younger individuals.

Secondary Bone Cancer

Secondary bone cancer, or metastatic bone cancer, typically originates from other parts of the body. When cancer cells migrate from their primary location to the bones, it's termed metastatic bone cancer. Several malignancies can metastasise to the bones, including:

• Breast cancer
• Prostate cancer
• Lung cancer

Bone Cancer Stages

The staging of bone cancer is crucial as it helps determine the extent of the disease and guides the treatment approach. The American Joint Committee on Cancer (AJCC), or the TNM system, is the most widely accepted staging system for bone cancer. This system evaluates three primary factors:

• T (Tumour): Indicates the size and extent of the primary tumour.
• N (Node): Denotes the absence or presence of cancer in nearby lymph nodes.
• M (Metastasis): Specifies if cancer has spread to other parts of the body.
• G (Grade): Represents how abnormal the cancer cells look under a microscope and suggests how quickly the cancer might grow and spread.

The stages of bone cancer are:

Stage 1: Cancer is localised to the bone. It can be further divided into:

• Stage 1A: The tumour is small (less than 8 cm) and might be low-grade or undetermined.
• Stage 1B: The tumour is larger than 8 cm or found in multiple places within the same bone.

Stage 2: Cancer remains within the bone but is high-grade.

• Stage 2A: The tumour is less than 8 cm.
• Stage 2B: The tumour is larger than 8 cm.

Stage 3: Multiple high-grade tumours are present within the same bone.

Stage 4: Cancer has metastasised to other parts of the body. It can be further categorised into:

• Stage 4A: Cancer has spread to the lungs.
• Stage 4B: Cancer has spread to lymph nodes or another organ outside the lungs.

Also, Read - Ever Heard of Sarcoma?

Causes and Risk Factors of Bone Cancer

Understanding the risk factors associated with bone cancer can help in early detection and prevention. While the exact cause of bone cancer remains unknown, several factors can increase an individual's susceptibility:

• Genetic Factors: Some individuals may inherit genetic mutations that increase their susceptibility to bone cancer. For instance, certain hereditary conditions, like Li-Fraumeni syndrome and hereditary retinoblastoma, have been linked to an elevated risk of bone cancer. These conditions arise from specific gene mutations that can enhance the likelihood of cancer development.
• Radiation Exposure: Prolonged exposure to high levels of ionising radiation, either from previous radiation treatments for other cancers or from certain occupational sources, can increase the risk of bone cancer. The risk is particularly heightened if the radiation is administered during childhood.
• Bone Disorders: Pre-existing conditions affecting the bones, such as benign bone tumours or chronic osteomyelitis (long-standing bone infections), might slightly elevate the risk of bone cancer. The transformation of these conditions to malignancy, though rare, is a possibility.
• Past Cancer or Cancer Treatments: Individuals who have had cancers or undergone specific cancer treatments, especially radiation therapy, may have a marginally elevated risk of developing bone cancer later in life.
• Chemical Exposures: Prolonged exposure to certain chemicals, like beryllium or vinyl chloride, has been suggested in some studies to increase bone cancer risk. However, these associations require further research for confirmation.
• Paget's Disease of Bone: This is a rare bone disorder characterised by abnormal bone remodelling. While not all individuals with Paget's disease will develop bone cancer, the condition does elevate the risk, especially for osteosarcoma.
• Trauma or Injury: While the link between bone injuries and bone cancer isn't firmly established, some studies suggest that trauma might play a role in the development of bone tumours in rare cases.
• Environmental Factors: Some studies have hinted at a potential link between exposure to specific chemicals or toxins and an increased risk of bone cancer. However, these associations require further research for validation.

It's crucial to note that while these factors can increase the risk, they don't necessarily cause bone cancer directly. Many people with these risk factors never develop bone cancer, while others without any apparent risk factors do. 

Also, Read - 9 Common Bone Sarcoma: Myths & Facts

Bone Cancer Diagnosis

Diagnosing bone cancer involves a series of tests and evaluations to confirm the presence of cancerous cells in the bone and determine the extent of their spread. Here's a detailed breakdown of the diagnostic process:

Medical History and Physical Examination

Initially, your doctor will gather information about your symptoms, any prior medical conditions, and potential risk factors. A physical examination will help identify any noticeable lumps or areas of tenderness.

Imaging Tests

These tests provide detailed images of the bones and surrounding tissues, aiding in the identification of tumours or abnormalities.

• X-rays: The primary tool for spotting tumours in the bone. Abnormal bone growth or changes can be evident in X-ray images.
• CT Scans: These provide cross-sectional images of the body and can help determine the tumour's size and location.
• MRI scans: Using magnetic fields, MRI scans produce detailed images of bones and soft tissues, helping to differentiate between benign and malignant tumours.
• PET scans: By detecting areas of high sugar consumption in the body, PET scans can identify cancerous cells, which typically consume more sugar than normal cells.
• Bone Scans: After injecting a radioactive substance, this scan identifies abnormalities in the bones.

Blood Tests

While blood tests alone can't diagnose bone cancer, they can provide insights. Elevated levels of certain enzymes might indicate the presence of bone tumours.

Biopsy

This is the definitive method for diagnosing bone cancer. A sample of tissue from the suspected area is extracted and examined under a microscope to identify cancerous cells.

• Core Needle Biopsy: Most commonly performed, this procedure uses a hollow needle to extract tissue samples. It's typically an outpatient procedure done under local anaesthesia.
• Incisional Biopsy: In certain cases, a small surgical procedure might be necessary to obtain a larger tissue sample. This is done under general anaesthesia.

At specialised centres such as the Musculoskeletal Oncology Department of Max Hospitals, the majority of biopsies are core needle biopsies and are done as an OPD procedure. A small percentage of cases, however, may require an incisional biopsy.  

Bone Cancer Prognosis

The prognosis for bone cancer patients varies based on several factors, including the cancer type, stage, and overall health of the patient. Early detection and treatment significantly improve the chances of a favourable outcome. However, it's essential to be aware of the potential long-term effects of treatments, which can impact various body systems. Regular medical check-ups post-treatment are crucial to monitor for any complications or recurrence. With advancements in treatment options and supportive care, many bone cancer patients lead fulfilling lives post-diagnosis.

Treatments for Bone Cancer

Bone cancer treatment depends on the type of bone cancer. Every patient is evaluated in detail by a multidisciplinary team consisting of orthopaedic/musculoskeletal oncologists, paediatric/ adult medical oncologists, radiation oncologists, radiologists, pathologists, and other specialities. A treatment plan is thus made on day one and started as soon as possible after the initial evaluation. Here's a quick overview of potential treatment options for bone cancer:

Surgery

The primary method for treating localised bone cancers.

• Limb-Saving Surgery: This procedure aims to preserve as much of the affected limb as possible. The cancerous bone segment is removed and replaced with a metal implant or bone graft.
• Amputation: In cases where the tumour is extensive or involves critical blood vessels and nerves, removing the entire limb might be necessary. Prosthetic limbs can be fitted afterwards.

Radiation Therapy

Radiation therapy involves using high-energy X-rays to target and kill cancer cells. It's often used in conjunction with surgery, especially when the tumour is challenging to remove entirely.

Chemotherapy

This systemic treatment uses drugs to kill cancer cells or halt their growth. Depending on the cancer type and stage, chemotherapy might be administered before or after surgery.

Targeted Therapy

A newer form of treatment, targeted therapies specifically attack cancer cells based on their unique characteristics, minimising damage to healthy cells.

Regular Monitoring

Even after successful treatment, regular check-ups are crucial to monitor for any signs of recurrence and manage potential side effects of treatment.

Also, Read - Advances in orthopaedic oncology – Bone tumors can be treated without open surgery

Mitigating the Risk of Bone Cancer

Preventing bone cancer is challenging due to the limited understanding of its exact causes. However, awareness of risk factors and early detection can play a pivotal role in managing the disease. Here are some recommendations:

• Genetic Testing: For individuals with a family history of bone cancer or related genetic syndromes, genetic counselling and testing can provide valuable information about potential risks.
• Limiting Radiation Exposure: While radiation therapy is essential for treating certain cancers, it's crucial to minimise unnecessary exposure to ionising radiation.
• Regular Check-ups: Regular medical check-ups can help in the early detection of bone abnormalities or tumours, increasing the chances of successful treatment.
• Healthy Lifestyle: While there's no direct link between lifestyle factors and bone cancer, maintaining a healthy lifestyle, including a balanced diet and regular exercise, can boost overall health and reduce the risk of various diseases.

Does Surgery for Bone Cancer Mean Limb Amputation? 

No. Nowadays, at leading centres such as Max Hospitals, where these patients are routinely treated, up to 90% of patients undergo “limb salvage surgery”, where the tumour is completely removed while at the same time saving the form and function of the limb.  Amputation is required in only a small percentage of patients. You can also read about bone marrow cancer.

When to See a Doctor?

Bone pain can arise from a myriad of causes, ranging from benign conditions such as minor injuries or arthritis to more serious concerns like bone cancer. If you or someone you know experiences persistent or worsening bone pain, especially if it's accompanied by other symptoms like swelling, fatigue, or unexplained weight loss, it's essential to consult a medical professional promptly.

Specific signs that warrant immediate medical attention include:

• Pain that intensifies at night or disrupts sleep.
• Pain that persists even when at rest or not moving the affected limb.
• A noticeable lump or mass on a bone or in the surrounding tissue.
• Any pain or discomfort that doesn't improve with over-the-counter pain relievers or persists for more than a few weeks.
• Unexplained fractures or breaks from minor falls or injuries.

Early detection and diagnosis are paramount in managing bone cancer effectively. Therefore, any persistent or unusual bone symptoms should be evaluated by a healthcare provider to rule out serious conditions and ensure timely and appropriate treatment.

What Questions to Ask the Healthcare Expert? 

Being well-informed is crucial when dealing with a bone cancer diagnosis. Here are some pertinent questions to ask your healthcare provider:

1. What is the specific type and stage of my bone cancer?
2. What are the treatment options available for my diagnosis?
3. What are the potential side effects of the recommended treatments?
4. How will the treatment impact my daily life and long-term health?
5. Are there any clinical trials or experimental treatments available?
6. What is the prognosis, and what factors influence it?
7. How often will I need follow-up appointments post-treatment?
8. Are there any support groups or resources you recommend for bone cancer patients?