The prognosis of malignant bone tumors is closely related to the early and late treatment, so attention should be paid to the detection of early cases and early diagnosis and treatment in order to improve the five-year survival rate. China has made great progress in the treatment of osteosarcoma and other malignant bone tumors by using comprehensive treatment methods. Nowadays, more than 90% of patients can keep their limbs and the 5-year survival rate of patients is more than 60%. At present, the treatment methods of malignant bone tumor mainly include surgery, radiotherapy, chemotherapy and immunotherapy.
(a) Surgery: Surgery is the most used and most important method among the comprehensive treatment methods. Surgery should strive for thoroughness to avoid recurrence, but should try to preserve limb function. For malignant tumors, life saving should be the main concern, and limb preservation should be considered only if the survival rate is not reduced.
The limb preservation methods currently available are.
Human artificial prosthesis replacement: most of the primary tumor patients are young, with high activity, high load and high functional requirements; more bone tissues are resected and large defects, which require higher design, material performance and fixation techniques of prosthesis; the principle of tumor surgery requires extensive soft tissue resection, which inevitably changes the stress and balance mechanism of joint and prosthesis and reduces the stability of prosthesis; due to the individuality of tumor patients, the stability of tumor prosthesis is reduced. Because of the individuality of tumor patients, the production of tumor prosthesis also needs to be individualized.
Autologous bone grafting with vascular tip: It is suitable for malignant tumor of lower femur, upper tibia and distal radius, and knee fusion and shoulder and wrist arthroplasty after extensive resection.
Allogeneic bone and hemiarthroplasty: The advantages are that the bone is widely available and convenient to use; it can restore the continuity and volume of the bone, reconstruct the joint structure, and provide the attachment site for soft tissue; the bone reconstruction can be used for life after completion. The main complications are deep infection, bone resorption, bone non-union, fracture, joint surface collapse, internal fixation loosening and breaking, advanced joint degeneration and collapse, and joint instability.
Human artificial joint – allograft bone composite implantation: allograft bone graft is the best effect of large segment bone stem graft, while allograft hemiarthroplasty has more rejection reactions and more complications than the former, in order to avoid the shortcomings of allograft hemiarthroplasty and retain the advantages of large segment bone stem graft, allograft bone and artificial prosthesis composite implantation can be used. It is suitable for the reconstruction of hip and knee joint function after extensive resection of malignant tumor in the upper and lower femur.
Tumor bone shell inactivation and reimplantation: The advantages are simple surgery and low cost. Microwave in situ inactivation can maintain the continuity and original shape of the bone stem, reduce the impact on the activity and biomechanical properties of the bone tissue, and facilitate the reconstruction of the bone. The inactivated tumor cells can be used as antigens to stimulate the immune system and enhance the immune function. The disadvantage is that there may be fracture, plate and screw breakage, bone non-healing and other complications, and poor joint movement. It is suitable for patients with junctional and malignant tumors in the extremities, pelvis or shoulder with less serious bone destruction and less obvious bone strength damage.
Joint fusion: The advantages are good stability, low cost, and durable preservation of the limb. The disadvantage is that it cannot be moved and the function is not good, which brings inconvenience to life. It is suitable for adults with malignant bone tumor of femur, tibia, humerus, ulna, radius and upper and lower ends.
(2) Radiation therapy: As adjuvant therapy, radiation therapy also plays an important role in the comprehensive treatment of tumor. According to the sensitivity to radiation, tumors can be classified as highly sensitive, moderately sensitive, and insensitive. However, sensitivity and insensitivity are relative, not absolute. In order to facilitate the selection of radiation therapy, bone tumors can be divided into the following cases.
1.For those who apply radiation therapy: eosinophilic granuloma of bone, bone hemangioma, aneurysmal bone cyst, etc. are highly sensitive and have significant efficacy with conventional radiation amount for 3-4 weeks; multiple myeloma, Ewing’s sarcoma, giant cell tumor of bone are effective with twice the conventional radiation amount for 5-6 weeks.
2, radiation therapy after surgery: vertebral body giant cell tumor surgery is not complete can be supplemented with radiation therapy, the effect is better. Chordoma, osteosarcoma, chondrosarcoma and osteofibrosarcoma are not sensitive, so they are generally treated with postoperative radiation therapy, and twice the amount of conventional radiation is used for 6-7 weeks to prevent recurrence.
3, palliative radiotherapy; torso osteogenic sarcoma that cannot be removed surgically can be treated with radiation therapy to control its growth. Bone metastases can also reduce pain and sometimes limit their growth after radiation therapy.
4.Radiation therapy is prohibited for benign tumors, except for the above-mentioned types of tumors that are suitable for radiation therapy.
In addition to deep x-ray machine, cobalt 60 alpha ray has strong penetrating power and light skin damage, so it is widely used in radiotherapy. In addition, radioisotope phosphorus 32 can be used in the treatment of multiple myeloma, iodine 131 can be used in the treatment of thyroid cancer bone metastases, and gold 198 can be used in the treatment of intrathoracic metastases.
(C) Chemotherapy: chemotherapy of malignant tumors has developed greatly in recent years and become an important part of comprehensive tumor treatment. Applicable chemotherapy for bone tumors include undifferentiated reticulocytic sarcoma, primary reticulocytic sarcoma of bone, multiple myeloma and part of bone metastases.
Frequently used chemotherapeutic agents are alkylating agents, antimetabolites, antimicrobials, alkaloids and hormones. Among alkylating agents, nitrogen mustard hydrochloride and nitrogen mustard oxide are effective in reticulocytic sarcoma, cyclophosphamide is effective in undifferentiated reticulocytic sarcoma, reticulocytic sarcoma and multiple myeloma, N-formyl lysosarcoma is effective in arginogenic cell tumor bone metastases and primary myeloma, and thiotepa is effective in ovarian or breast cancer bone metastases. Among the antimetabolites, 5-fluorouracil is effective for bone metastases from intestinal cancer, and uratan is effective for multiple myeloma. Among the antimicrobial agents, rennithromycin (actinomycin D) and orthomycin (erythromycin) are effective against reticulocytic sarcoma, undifferentiated reticulocytic sarcoma and rhabdomyosarcoma. Colchicine agent (contender 81) among alkaloids is effective against bone metastasis of breast cancer. Male hormones among hormonal drugs can be used for bone metastasis of breast cancer, female hormones can be used for bone metastasis of prostate cancer, and adrenocorticotropic hormones can be used for bone metastasis of multiple myeloma and breast cancer.
(iv) Immunotherapy: With the progress of treatment methods of surgery, chemotherapy and radiotherapy, the long-term survival rate of patients with malignant bone and soft tissue tumors has been improved, but some patients are still not immune to recurrence or metastasis. About more than 60% of patients with malignant bone and soft tissue tumors have microscopic metastases at the time of surgery, and surgery or even radical surgery can only address local tumors but not systemic metastases. Research shows that surgery, radiotherapy and chemotherapy can cure some tumor patients, not because they kill all tumor cells, but because when the tumor cell load is obviously reduced, the immune function of the body recovers and removes the tiny residual lesions or obviously inhibits the proliferation of residual tumor cells. This indicates that body immunity has important significance to tumor growth and transformation.
The greatest advantage of immunotherapy for tumor is that it targets tumor cells, even non-specific killer cells such as natural killer cells are still stronger than normal cells in killing tumor cells, which is especially valuable for patients whose immune function has been affected and still need radiotherapy or chemotherapy. However, because the mechanism of tumorigenesis is not yet fully understood, except for a small number of tumors that can easily stimulate the immune response of the body, most of them are difficult to stimulate the immune response of the body, which brings many difficulties to immunotherapy. After years of basic and clinical experimental research, tumor immunotherapy has made great progress and has shown attractive development prospects. However, because the process of tumor development is very complicated and there are many influencing factors, there are still many problems to be solved by in-depth research.
The main purpose of treatment for malignant bone tumors is to preserve the function of limbs and maintain the normal structure of bones and joints as much as possible on the basis of saving patients’ lives, that is, to minimize the impact on patients’ quality of life. As the development of artificial joint prosthesis and the combined application of radiation, chemotherapy, immunotherapy and other methods have provided important conditions for limb-preserving surgery, the choice of surgery that can completely remove the tumor while preserving or reconstructing the function of the limb has become the main development direction of surgical treatment of bone tumor. The use of artificial prosthesis for bone tumor treatment is one of the main limb preservation surgeries, and full understanding and correct selection of artificial prosthesis is the key to improve the efficacy and restore the function.