Bone tumors Dr. Mohammad Q. Hamdan
Overview �Bone tumors are abnormal growths of cells within the bone that may be: • noncancerous (benign) • or cancerous (malignant) � For most bone tumors the cause is unknown. �Possible causes include genetic defects passed down through families, radiation, and injury.
�A bone tumor may be primary: originating within the bone itself, �secondary, resulting from the spread (metastasis) of cancer elsewhere in the body, such as from the lung, breast, or prostate.
Benign bone tumors �occur more frequently than malignant bone tumors. �remain localized within the bone and do not metastasize to other tissues or organs � can enlarge in the bone or the surrounding tissue but not always. �benign bone tumors may cause fracture (pathological fracture) …. surgery. � Local recurrence depends on the type of benign bone tumor after surgery.
Benign tumors �named according to the cell type of origin: bone cells (osteoblasts) may produce osteomas �cartilage cells (chondroblasts) may produce chondromas �tumors arising from both bone and cartilage produce osteochondromas
�Osteochondromas are the most common benign bone tumors. �Other benign bone tumors include non-ossifying fibroma, unicameral (simple) bone cyst, giant cell tumor, enchondroma, and fibrous dysplasia
Malignant bone tumors �are classified as primary and secondary. �The most common types of primary bone cancer are multiple myeloma, chondrosarcoma, osteosarcoma, and Ewing's sarcoma. � Fibrosarcomas arise from connective tissue (muscle, ligament, or tendon) but may affect the bones of the jaw, arms, and legs.
Chondrosarcomas �are the second most common bone cancer in adults. �They arise from cartilage cells and develop in the legs, shoulders, arms, hips, pelvis, or ribs. �They may also arise from benign enchondromas and osteochondromas
Osteosarcomas �are bone-forming tumors that develop primarily at the ends of the bones in the growth plates of children and young adults (most cases occurring in teenagers) �affect the knee, hip, and shoulder, in that order.
Ewing's sarcoma �a rare malignant tumor of the bone �the second-most-common type of bone cancer in children, � develops most frequently in the middle (shaft) of long bones, and affects the hips, long bones in the upper and lower leg, pelvis, upper arm, and ribs.
�There are several other types of sarcoma, such as malignant giant cell tumors and chordoma. �These rare tumors occur most often in adults over the age of 30.
Secondary bone cancer �occurs when malignant cells from a primary cancer site, such as the kidney, lung, prostate, breast, or thyroid, metastasize to the bones; � although cancer is present in the bones, the malignant cells are those of the organ of origin. � (e. g. metastatic lung cancer). �Common sites of secondary bone cancer include the ribs, skull, pelvis, and vertebrae.
�These bone tumors may not be treated in the same way as primary bone tumors because they occur in the later stages of metastatic cancer of other organ systems. �Sometimes, when metastasis of the primary tumor involves bone and other organ systems, only palliative treatment is given.
Incidence and Prevalence �According to the American Cancer Society, an estimated 3, 010 new cases of malignant bone tumors were diagnosed in 2013 in the US, with an estimated 1, 440 deaths �According to the Multiple Myeloma Research Foundation, more than 56, 000 Americans are living with the disease. � MM is usually diagnosed between the ages of 50 and 70 and can involve any bone.
�Chondrosarcoma and osteosarcoma account for about 40% and 28% of primary bone cancers in adults, respectively. � In the US each year, 400 new cases of osteosarcoma are diagnosed � the incidence among blacks is 5. 2 cases per 1 million each year, and among whites it is 4. 6 cases per 1 million each year
�Fibrosarcoma and malignant fibrous histiocytoma account for 4% of primary bone cancers, �chordoma accounts for 10%. �Ewing's sarcoma of the bone accounts for 8% of cases of primary bone cancer with the incidence in whites about 9 times that in blacks. � Rare tumors, such as giant cell tumors, make up the remainder of primary bone cancers.
Causation and known risk factors �Primary malignant bone tumors are rare, and in most cases a direct cause is unknown. �Certain genetic risk factors may be associated with a propensity for the development of sarcomas. � Loss of tumor suppression mechanisms is also believed to increase risk
�Excessive exposure to radiation, especially at a young age may increase the risk of bone cancer, �combinations of radiation and chemotherapy for treating prior cancer may increase the risk of bone cancer. �Individuals who have had multiple benign tumors (osteochondromas), � who have been diagnosed with Paget's disease, � who have a long-term bone infection (osteomyelitis) may also be more likely to develop primary sarcomas.
Osteosarcomas �Men are more likely than women to develop osteosarcoma, �more teenagers than adults will be affected. �most commonly diagnosed in individuals between the ages of 10 and 30 and between the ages of 60 and 80; �they are rarely discovered in middle age �Gene mutations are present in a significant number of individuals with osteosarcoma.
Chondrosarcomas �unusual in those younger than 20 years of age; �there is increasing risk from age 20 to age 75, with most cases occurring in individuals between 40 and 70 years of age; �men and women are equally affected. �Chondrosarcomas may also arise from benign lesions (e. g. , enchondromas and osteochondromas) or in individuals with hereditary multiple exostosis or enchondromatosis
Fibrosarcomas �usually occur in middle-aged and elderly adults.
�Ewing's sarcoma occurs primarily in children and teenagers, and is uncommon in adults over the age of 30; � 27% of cases occur before age 10, � 64% before age 30, �and only 9% over age 30. �most cases occur between 5 and 20 years of age. �Whites are at higher risk for this type of primary bone cancer, and it is rare in blacks and Asian Americans. � Almost all Ewing's sarcomas (95%) involve a translocation between chromosomes 11 and 12, creating an abnormal protein that predisposes the individual to abnormal cell growth (tumorigenesis)
Diagnosis �History: �Many benign bone tumors have no symptoms at all and may be found incidentally. �The most common symptom reported with malignant bone tumors is pain, especially pain that worsens with activity and at night. � Other symptoms : swelling, stiffness, tenderness, or a mass that can be felt at the tumor site � Bone fractures (pathological fractures), may have occurred.
�Individuals with Ewing's sarcoma often report constitutional symptoms such as malaise, fever, and weight loss. �Pallor and weight loss may also indicate poor general health stemming from underlying metastatic cancer in another organ.
Diagnosis �Physical exam: �swelling or a palpable soft-tissue mass �decreased mobility in an affected joint, �muscle wasting, �limping � Individuals with rare bone tumors may also present with an enlarged liver or spleen. � If metastatic cancer …. complete physical is usually performed to assess the presence of the tumor in another organ system.
�Tests: � Definitive diagnosis of bone tumors depends on obtaining a biopsy of the tumor tissue. � Percutaneous imaging-guided needle biopsy or bone marrow needle aspiration biopsy are able to accurately diagnose 90% of bone tumors
�Diagnostic imaging: � x-rays �size and shape of the tumor, �whether it is destroying bone or forming abnormal bone �periosteal reaction �Most bone tumors can be visualized on x-rays of the affected bone or joint.
�Magnetic resonance imaging (MRI) is especially useful to show details of normal versus cancerous tissue.
�preoperative tests may include: � a chest x-ray; �brain and pulmonary computed tomography (CT); MRI; �complete blood count (CBC), �coagulation tests, �a chemistry profile, including alkaline phosphatase and lactate dehydrogenase levels that correlate with survival of individuals with osteosarcoma and Ewing's sarcoma �a bone scan (scintigraphy) may be performed to evaluate whether a malignant tumor has metastasized to other areas of bone
Treatment �Some benign bone tumors may not require treatment, but will be assessed periodically to check for progress or regression. � Other benign bone tumors may require open or radical surgery (resection). � Some benign tumors are resected using a bonescraping procedure called curettage. � If structural bone is removed, reconstruction is performed using a combination of bone grafts and stabilization to prevent fracture.
�Most malignant bone sarcomas are treated with a combination of therapies, including surgery, chemotherapy, and radiation. �Chondrosarcomas treatment is primarily wide surgical excision.
�Advances in the treatment of most other types of malignant bone tumor include the use of pre- and postoperative multi-agent chemotherapy, � neo-adjuvant chemotherapy. � A response to chemotherapy that results in greater than 90% tumor cell or tissue death (necrosis) is considered a good response. �Ideally, individuals with a good response to chemotherapy are considered good candidates for limb-salvage surgery. � A poor response to chemotherapy may lead to amputation in up to 10% of cases �Surgery is followed by a course of postoperative chemotherapy.
�In many instances, adjuvant radiation is used in combination with chemotherapy for tumor control in the surrounding tissue. � Rehabilitation and physical therapy programs are often indicated after chemotherapy, radiation, or surgery.
�Treatment for metastatic malignant tumors depends upon the primary tissue or organ in which the original tumor developed
Prognosis �Most individuals with benign bone tumors are completely cured with treatment, �although a functional loss may occur depending on how much bone and soft tissue is removed to obtain a wide margin excision.
�The outcome for malignant tumors depends on the tumor grade, whether the tumor has invaded the center of the bone, and whether the cancerous cells have metastasized. �Low-grade malignant tumors have an excellent prognosis
� Individuals with low-grade osteosarcomas are frequently treated with surgery only and have a better survival rate than individuals with higher-grade osteosarcomas. � Most treatment failures are due to the presence of distant metastasis. �The 5 -year survival rate for high-grade osteosarcoma (with bone metastases) is under 25%. � The 5 -year survival rate for nonmetastatic (lowgrade) osteosarcoma is 60% to 70%.
chondrosarcoma �Individuals with low-grade, stage I tumors that have not metastasized have a 90% survival rate. �Individuals with chondrosarcomas that have spread to lymph nodes and other organs have a 5 -year survival rate of 29%. � The pelvis as a primary site of disease also carries a worse prognosis than peripheral sites because surgery may not be an option.
Ewing's sarcoma �The expected survival rate is 70% for nonmetastatic disease at the time of diagnosis �A less favorable long-term survival rate of lower than 25% is expected for individuals whose cancer has spread
Rehabilitation �Rehabilitation for individuals with bone tumors depends on: � the location of the tumor, �whether the tumor is benign or malignant, � and whether limb-salvage surgery or amputation is required.
�If surgery is required, rehabilitation may include therapy to regain range of motion, strength, and functional mobility following limb-sparing surgery, � or fitting of a prosthesis and movement retraining following amputation. �If the bone tumor affects a lower extremity, the physical therapist will also focus on gait training for proper ambulation (walking) at the appropriate time.
� Occupational therapy will help individuals arrange their homes and organize their lives in ways that support their physical and mental well-being, and will provide activities to relieve the boredom of inactivity.
�Supportive rehabilitation allows the individual to gain some control over the ordinary activities of life and to cope emotionally. �This may take the form of group vocational rehabilitation and may help with the individual's transition back into the workplace.
�Palliative rehabilitation allows individuals in advanced stages of the disease to achieve some level of physical comfort, and provides emotional support and assistance in day-to-day functioning