Bone cancer is a serious condition that affects the bones in the body. Here are some key points about bone cancer:

1. Types:
- Primary bone cancer: Originates in the bone
- Secondary bone cancer: Spreads to the bone from other parts of the body

2. Common primary bone cancers:
- Osteosarcoma
- Chondrosarcoma
- Ewing sarcoma

3. Symptoms:
- Bone pain, especially at night
- Swelling and tenderness near the affected area
- Weakened bones, leading to fractures
- Fatigue
- Unexplained weight loss

4. Risk factors:
- Previous radiation therapy
- Certain genetic conditions
- Paget's disease of bone
- Certain bone disorders

5. Diagnosis:
- Physical examination
- Imaging tests (X-rays, CT scans, MRI, bone scans)
- Biopsy

6. Treatment options:
- Surgery
- Chemotherapy
- Radiation therapy
- Targeted therapy
- Immunotherapy

7. Prognosis:
- Varies depending on the type, stage, and location of the cancer
- Early detection and treatment can improve outcomes