As a front-line clinician specializing in bone tumor, whenever I encounter parents with their children, I often get a plausible response in the face of the physician’s tireless explanation of the disease. In view of this, I would like to list some questions from patients’ families as follows.
1.Why do osteosarcoma patients need chemotherapy?
Osteosarcoma is the most common primary malignant bone tumor in children and adolescents. In the past, the clinical prognosis of patients with osteosarcoma was very poor, but with the use of adjuvant chemotherapy and neoadjuvant chemotherapy in osteosarcoma, the survival rate of patients with osteosarcoma has improved significantly. Currently, the 3-year disease-free survival rate of patients has increased to 60%-70%, the 5-year disease-free survival rate and 5-year survival rate are 57% and 66%, and the 10-year disease-free survival rate and 10-year survival rate are 52% and 57%. The above set of data indicates that osteosarcoma, as a group of systemic diseases, is often mainly manifested by the early detection of local masses and often combined with pulmonary metastases in the late stage, and the main purpose of chemotherapy is to control the primary tumor and possible distant micro-metastatic lesions. Liu Bin, Department of Bone Oncology, Affiliated Cancer Hospital of Guangxi Medical University
2.What is the difference between amputation and non-amputation for osteosarcoma patients?
Nowadays, limb preservation gradually starts to be accepted by people. By comparing the functional results after amputation and limb preservation, it is found that limb preservation can provide better functional recovery and does not reduce the survival rate of patients. Over the past two decades, patients have experienced significant improvements in quality of life and limb condition after treatment, with limb preservation rates greater than 90%. —- With the implementation of adjuvant chemotherapy, there is no difference in patient survival rate by comparing the survival time of patients with amputation and limb preservation, so the current mainstream is limb preservation, provided that there is no contraindication to limb preservation.
3.What are the objectives and principles of limb-sparing surgery for osteosarcoma?
Limb-sparing surgery for pediatric and adolescent patients has certain indications.
(1) The growth and development of the patient’s skeleton has basically matured, and the age should preferably exceed l5 years.
(2) Enneking surgical stages I and IIA are ideal; stage IIB patients with good response to chemotherapy may also be considered, but should be strictly controlled.
(3) Absence of major vascular nerve involvement, pathological fracture, local infection and diffuse skin infiltration.
(4) Able to remove the tumor completely outside the tumor, with adequate skin and soft tissue coverage.
(5) The preserved limb is expected to function better than a prosthesis after reconstruction.
(6) The local recurrence rate of limb preservation surgery will not be higher than amputation and the expected survival rate will not be lower than amputation
(7) The patient and his family have a strong desire to preserve the limb. San et al. reported 40 children with bone tumors, all younger than 10 years old (2-10 years old), with an average follow-up of 11.2 years (5-19 years), with a 90% limb preservation rate and excellent functional recovery in 80% of the children. This indicates that limb-preserving surgery can also be applied to patients with bone tumors in young children. Currently, age is no longer a contraindication to limb-sparing surgery. The choice of surgical plan should be designed specifically according to each individual’s condition.
4. Can patients with osteosarcoma combined with pathological fractures be operated?
With the help of neoadjuvant chemotherapy, patients with pathological fractures can also undergo surgery, and limb-sparing surgery does not increase the rate of local recurrence or death. Patients with pathologic fractures have a significantly higher rate of local recurrence and a significantly lower survival rate. However, limb-sparing surgery does not significantly increase the rate of local recurrence or decrease survival when patients with pathologic fractures are carefully screened preoperatively. This requires the operator to take into account the patient’s responsiveness to chemotherapy and the degree of fracture healing before limb-sparing surgery. —- Combined pathological fractures are not an absolute contraindication to limb-sparing.
5.What is the difference between adult and pediatric limb preservation for osteosarcoma patients?
Most malignant bone tumors in children are located in the epiphysis of the limb. In order to completely remove the tumor, the epiphysis and epiphyseal plate of the joint near the tumor are removed together, which will inevitably cause problems such as unequal limb length and unsatisfactory joint function recovery after surgery. Meanwhile, the use of neoadjuvant chemotherapy may inhibit the growth of the limb and affect the limb length. However, there are controversial views on this aspect. Some scholars believe that the epiphyseal growth of children during neoadjuvant chemotherapy is significantly retarded, but there is an accelerated growth period after the end of chemotherapy, so chemotherapy has little effect on the final limb length. Limb length inequality is an important problem facing limb-preserving reconstruction in children. Limb inequality, especially in the lower extremity, has a greater impact on pediatric patients with immature bones. If the expected length discrepancy is greater than 2 to 3 cm, the appropriate method of management is required. Although many methods are available to compensate for limb inequality, each method has its own drawbacks and shortcomings. futani et al. performed a retrospective analysis of 40 patients younger than 11 years of age to evaluate their function and complications. The children were reconstructed with either prosthetic or biological reconstruction methods. The results showed that limb preservation with implantable prosthesis or biological reconstruction resulted in better functional recovery, but a higher percentage of revision surgery and limb lengthening was required —- The main problem of limb preservation in children is the problem of limb inequality.
6.The main methods of limb preservation for children with osteosarcoma?
(1) Prosthetic reconstruction: including ordinary implantable artificial prosthesis, invasive lengthenable prosthesis, non-invasive lengthenable prosthesis limb preservation surgery.
(2) Allogeneic bone (joint) transplantation.
(3) autologous bone grafts: fibula grafts with vascular tips, inactivated replantation of autologous tumor bone.
(4) allogeneic bone composite graft: prosthetic composite graft, autologous bone composite graft
(5) metastatic bone growth.
(6) Rotational plication.
(7) joint fusion.
(8) Epiphyseal preservation —- The method of limb preservation varies from person to person and is problem-specific.
7.What are the complications of surgery after limb preservation in children with osteosarcoma?
(1) Fracture
Fracture is the most common complication, especially in the case of allogeneic bone graft. Most fractures occur 3 to 4 years after limb-sparing surgery.
Most fractures occur 3 to 4 years after limb-sparing surgery. With the vascularization and regeneration process, the density of the allograft bone gradually decreases and reaches the level of the autologous bone in the adjacent site. Fractures may occur with the process of hematologic reconstruction or may be associated with bone discontinuity at the surgical site. Fractures are more common in pediatric patients, probably because of the more extensive hematologic reconstruction in children. Fractures that occur after autologous bone graft reconstruction may result from normal stresses on the smaller autologous bone.
(2) Infection
Current treatments for bone tumors are accompanied by a high incidence of infection, with infection of orthopedic devices being the most common cause of amputation and poorer functional outcomes. Therefore, improvements in current treatment methods are needed to reduce the incidence and severity of infection.
(3) Local recurrence
Local recurrence may be indicative of a poorer prognosis for the patient. Local recurrence often occurs in the soft tissues adjacent to the surgical site and may also occur at the bone to prosthesis junction. Amputation is not always necessary for local recurrence, and extensive resection followed by radiation therapy is a more feasible approach as long as the extent of surgery is adequate.
(4) Loosening
Currently, large implantable prostheses are widely used after oncologic surgery to facilitate early recovery of patient activity. The survival of the prosthesis depends on the anatomical site, type of prosthesis and fixation pattern. Re-operation is frequently required due to the occurrence of aseptic loosening. However, secondary insertion of the prosthesis is often more difficult due to the poor condition of the remaining bone, and aseptic loosening tends to recur quickly.
(5) Other prevention and control measures
Bone and soft tissue defects resulting from limb preservation surgery sometimes require multiple surgeries to ensure soft tissue coverage and bone continuity. Postoperative complications need not be underestimated and should be closely observed after surgery