Chapter 57 Osteogenic Sarcoma
PATHOPHYSIOLOGY
Osteogenic sarcoma, also known as osteosarcoma, is a tumor found in the diaphysis of a long bone (femur, radius, ulna, proximal humerus, or ilium). It also can affect the flat bones, which include the head, the pelvis, and the spine. The most common sites of occurrence are the femur and the knee, followed in order by the tibia, the humerus, the pelvis, the jaw, the fibula, and the ribs. The clinical course takes the following sequence: (1) the normal bone is destroyed and is replaced by tumor cells, which results in osteoid tissue and bone; (2) growth penetrates the cortex and extends beyond it (radiating spindles of bone are characteristic of this process); and (3) the tumor extends through the bone marrow cavity. Metastasis occurs through veins and involves the lungs first.
INCIDENCE
1. Osteogenic sarcoma is the most common bone tumor in children and accounts for 60% of malignant bone tumors in children under 15 years of age.
2. It occurs most commonly during the adolescent growth period and in young adulthood.
3. It is uncommon before age 10 years.
4. Age range of peak incidence is 10 to 15 years.
5. More males than females are affected.
6. Surgery and chemotherapy can extend the overall survival rates from 65% to 75%.
7. Two thirds of those with nonmetastatic osteogenic sarcoma will be long-term survivors after treatment with surgery and chemotherapy.
CLINICAL MANIFESTATIONS
Symptoms are gradual in onset. The child may have symptoms for 6 to 9 months before treatment is sought. Children often present with a history of a minor injury while participating in sports. The symptoms are as follows:
COMPLICATIONS
Complications of Amputation are the Following:
1. Reactive hyperemia—reddened skin, particularly at pressure points; subsides as keratoma layer forms
2. Contact dermatitis—most often caused by contact with prosthetic materials (e.g., polyester resins, chrome)
3. Infections—including fungal and pyogenic infections (e.g., furuncles)
4. Epidermal cysts—evident at points of friction at or near brim of socket; most often caused by ill-fitting prosthesis
5. Stump edema syndrome—consisting of worsening reactive hyperemia, which results in oozing and capillary rupture
7. Bony spurs—developing at corners or margins of amputation as a result of periosteal irritation
8. Neuroma—a nerve tissue tumor
9. Phantom limb—feelings of pain and sensation in the amputated limb
10. Stump scarring—caused by inguinal weight bearing and increased shearing force at stump-socket interface
LABORATORY AND DIAGNOSTIC TESTS
1. Serum alkaline phosphatase levels—confirms diagnosis; elevated because of osteoid production (see Appendix D, for normal range)
2. Tissue biopsy—reveals presence of malignant cells
3. Anteroposterior lateral radiographic studies—detect presence of soft tissue mass associated with destructive bone lesion, and calcification
4. Skeletal bone scan—detects presence of metastatic bone lesions
5. Computed tomography and magnetic resonance imaging—determines extent of disease and metastasis
MEDICAL AND SURGICAL MANAGEMENT
An important component of treatment of osteogenic sarcoma is surgery. Osteogenic sarcoma is resistant to radiation therapy; therefore, the most important prognostic factor is the ability of the physician to resect the tumor. Chemotherapy may be used before and after surgery. Type of surgery is determined by the age of the child and tumor size and location. It may be either an amputation or a limb salvage. Because of the availability of new chemotherapy regimens and complex reconstruction surgeries, amputation is no longer the surgery of choice. Minimally invasive surgery for diagnosis and treatment of solid tumor in children, such as osteogenic sarcoma, has become the preferred surgery. Both procedures are performed to excise the tumor and obtain a biopsy specimen for diagnosis. Following surgery, routine postoperative care is provided as described in the Nursing Interventions section in this chapter, in addition to monitoring complications following surgery as identified in the section on Complications.
Chemotherapy may be given before surgery in an attempt to promote the success of the surgery by first decreasing the tumor size. Preoperative tumor response to chemotherapy has been found to be very important in the prognosis of patients with nonmetastatic osteogenic sarcoma. Both intravenous and intraarterial chemotherapy may be given preoperatively.
