Understanding Osteosarcoma: Symptoms Causes and Treatments

Author: Han Xiuxin, Tianjin Medical University Cancer Hospital

Understanding Osteosarcoma: Symptoms, Causes, and Treatments

I. Understanding the 'King of Bone Cancers in Adolescents' - Osteosarcoma

When we hear the word 'cancer,' we often think first of lung cancer, breast cancer, thyroid cancer, stomach cancer, and so on. However, in the skeletal system, there exists a highly malignant tumor that particularly affects children and adolescents, known as the 'king of adolescent bone cancers,' which is osteosarcoma. Understanding its characteristics is key to early detection, early diagnosis, and early treatment, which are crucial in overcoming this 'king of bone cancer.'

What is osteosarcoma?

Osteosarcoma, as its name suggests, is a malignant tumor that originates from the bone itself and is capable of producing immature bone tissue. It is most commonly found in adolescents aged 10 to 20, with an annual incidence rate of about 2 to 3 cases per million people. Although it represents a small percentage of all human malignant tumors (approximately 0.2%), it constitutes 11.7% of primary bone tumors, making it the most common primary malignant bone tumor in children and adolescents.

III. Clinical Characteristics of Osteosarcoma

The most typical characteristics of osteosarcoma are pain and local swelling. Initially, the pain may be intermittent but gradually worsens, transforming into persistent severe pain, especially noticeable at night. This pain is often confused with growing pains, which can lead to a delay in diagnosis. The tumors commonly occur in areas of active growth, such as the distal femur (near the knee joint), proximal tibia, and proximal humerus. High-risk populations include not only adolescents but also those with hereditary syndromes, such as Li-Fraumeni syndrome characterized by TP53 gene mutations and individuals with a history of retinoblastoma, who face a higher risk of developing the disease. Additionally, it is also relatively common as a secondary malignant bone tumor following radiation therapy.

IV. Prevention and Screening of Osteosarcoma: The Key is to Be Aware of Early Signals

Currently, there are no specific preventive measures or screening methods for osteosarcoma. Therefore, it is crucial to remain vigilant and recognize early symptoms. If you or your child experience any of the following, please seek medical attention promptly: persistent and progressively worsening bone pain of unknown origin, especially pain that occurs at night; the presence of a painless or painful mass or swelling near the joint ends, which may involve increased local skin temperature and even visible varicose veins; recurrent pain or swelling in the same area that does not relieve with rest and is not related to sports injuries. If any of these symptoms appear, it is vital to visit a specialized center for bone tumor treatment as soon as possible. Doctors will conduct a detailed medical interview, physical examination, and employ imaging studies (such as X-rays, CT scans, MRI, etc.) for preliminary evaluation.

Diagnosis and Treatment of Osteosarcoma: Integrated Therapy is the Core Weapon

The diagnosis and treatment of osteosarcoma is a systematic process that emphasizes 'integrated diagnosis and treatment,' meaning collaboration among a multidisciplinary team.

V. Accurate Diagnosis

Imaging examinations include X-rays, enhanced CT scans, and enhanced MRI of the lesion site, which are used to assess the extent of the tumor and its relationship with surrounding blood vessels and nerves. A chest CT is essential, as the lungs are the most common site for osteosarcoma metastasis. Whole-body bone scans or PET/CT scans help to identify lesions in other regions.

Pathological biopsy: This is the definitive 'gold standard' for diagnosis. Typically, image-guided puncture biopsy is prioritized to obtain tissue for pathological analysis. The design of the biopsy pathway is crucial, as it must ensure that the puncture tract is removed during subsequent surgery to prevent tumor dissemination.

VI. Comprehensive Treatment

The treatment of osteosarcoma has evolved from the past practice of simple amputation surgery to a comprehensive model primarily involving neoadjuvant chemotherapy, surgery, and adjuvant chemotherapy. This integrated approach has significantly increased both the cure rate and limb preservation rate.

Chemotherapy: It is the cornerstone of treatment. It is usually administered before surgery (neoadjuvant chemotherapy) with the aim of shrinking the tumor, destroying potential microscopic metastases, creating better conditions for limb-sparing surgery, and assessing the tumor's sensitivity to medication. Commonly used chemotherapy drugs include doxorubicin, cisplatin, high-dose methotrexate, and ifosfamide. Post-surgery, adjuvant chemotherapy is completed based on the effectiveness of the chemotherapy (assessed through the rate of tumor necrosis).

Surgery: The goal is to completely remove the tumor. Nowadays, about 90%-95% of patients with limb osteosarcoma can undergo limb-salvage treatment, which means that after tumor resection, limb function can be restored using artificial prostheses, allograft bone, or reimplantation of deactivated tumor segments. Amputation is only considered when the tumor invades important blood vessels and nerves, chemotherapy is ineffective, or achieving a safe margin for limb salvage is not possible. For tumors located in special areas such as the pelvis and spine, the surgical challenges are greater; however, with the aid of technologies like 3D printing and computer navigation, precise resection and reconstruction can still be achieved.

Radiation therapy: Osteosarcoma is not sensitive to conventional radiation therapy. However, for cases where complete surgical resection is not possible or when surgical margins are positive, particularly for tumors located in the pelvis, spine, or other areas, radiation therapy can serve as an important adjunct treatment. Precision radiation techniques such as proton or heavy ion therapy have shown certain advantages.

Targeted and Immunotherapy: For recurrent or refractory osteosarcoma, targeted drugs (such as Anlotinib, Regorafenib, Apatinib, etc.) offer new options for patients. Immunotherapies, including immune checkpoint inhibitors, are also being explored and may provide hope for some patients.

Treatment prognosis: Prognosis is related to multiple factors, including whether the tumor has metastasized at the time of initial diagnosis, the tumor's response to chemotherapy, and whether surgery can achieve safe surgical margins, among others.

VII. Rehabilitation and Follow-up of Osteosarcoma: A Bridge to Returning to Normal Life

The end of treatment does not mean the end of care; systematic rehabilitation follow-up is key to ensuring long-term quality of life. Functional rehabilitation: Postoperative recovery should be conducted in phases. In the early stage, the focus is on promoting wound healing and preventing complications; in the intermediate stage, the goal is to gradually restore joint mobility and muscle strength; in the later stage, the aim is to further improve physical fitness, with the ultimate goal of allowing patients to return to normal life and learning. For patients who have undergone lower limb surgery, gait training and balance training are particularly important. Regular follow-ups: After treatment, it is essential to strictly adhere to the follow-up plan, typically involving a review every three months for the first two years, then every four months in the third year, gradually extending the intervals afterward. Follow-up assessments include physical examinations, imaging studies of the surgical site (such as ultrasound and MRI/CT), and chest CT, aimed at early detection of local recurrence or distant metastasis.

VIII. Psychological Support Therapy

Suffering from osteosarcoma is a tremendous psychological challenge, especially for adolescent patients and their families. Positive psychological intervention and social support are crucial in helping patients build confidence, successfully complete their treatment, and reintegrate into society.

In summary, although osteosarcoma is highly malignant, it is not an incurable disease. In facing it, we need to have a scientific understanding: be vigilant about unexplained bone pain and masses, and seek medical attention early; trust in a professional multidisciplinary team specialized in bone tumors and undergo standardized integrated treatment; and place importance on systematic rehabilitation and long-term follow-up after treatment. Through the collaboration between doctors and patients, it is entirely possible to overcome this 'king of adolescent bone cancers' and restart a wonderful life.