Everything you need to know about bone cancer and how to treat it

Cancer can affect any part of the body including the bones, a rigid framework that protects soft organs and supports the body resulting in weakening of bone strength and flexibility. Bone cancers affect the normal movement of the organ and can result in pain, lumps or swellings and in rare cases can result in fractures as well. It is important to understand the signs of bone cancer to detect it in the early stage.
Bone cancer, though rare, is triggered when the cells in any bone turn cancerous. It mostly affects the pelvic bones or the long bones of the limbs. When left untreated, they tend to spread to other organs, including the lungs and liver.
While some bone cancers are often hereditary or due to exposure to radiation, the exact causes of bone cancer remain unknown in most patients.

Primary and Secondary Bone Cancers
Bone tumors or cancers may originate anywhere on any bone, be it in the hard outer layer or the Cortical part, the soft spongy part or the trabecular part. Bone cancer often destroys the healthy tissues, leaving the bone weakened and brittle.
If diagnosed as cancerous, it is classified as a primary bone cancer or a secondary bone cancer. While a primary bone cancer begins in the bone, the secondary bone cancer originates in other parts and spreads into the bone. The secondary bone cancer mainly originates in the breast, thyroid glands, prostate glands, lungs and kidneys.
There are several types of bone cancers.
●                The most common primary bone cancer is osteosarcoma. It’s mostly seen from the ages of 10 years and 30 years. It begins in the bone-forming cells and is commonly found in the long bones in the limbs. But, it can begin in any bone, rarely originating in the soft tissues.
●                Ewing’s Sarcoma is commonly seen beginning in the leg bones and the pelvic area. But, it can occur in any bone in the body. In some rare cases, Ewing sarcoma begins in the tissues around the chest, limbs, abdomen, as well as in other parts.
 
This is often seen in children and teenagers but can occur among other age groups as well.
 
●                A rare cancer found in the cartilage cells is the chondrosarcoma. It is rarely seen in people below the age of 20 years, and the risk rises as people age. This type of cancer is mostly found in the pelvic bones, shoulders, and hip bones. It can also occur in the spine bones. Since the chondrosarcomas tend to grow slowly, it is difficult to identify symptoms at the outset, thus difficult to treat.
●                A cancer that starts in the soft tissues such as the ligaments, tendons, fat, and muscle is the high grade undifferentiated pleomorphic sarcoma of the bone. It often occurs in the elderly and middle-aged adults and is rare in children.
●                A cancer that occurs in the soft tissues around the bone is the fibrosarcoma. It usually arises in the soft tissues around the bone and bones in the legs, arms and jaw.
 
Giant cell tumor of the bone and chordoma
●                Though not considered a primary bone tumor, the Multiple Myeloma that's mostly associated with bone lesions, arises from the plasma cells in the bone marrow.
 
Identifying Bone Cancer’s Symptoms
Local bony pain or swelling can be a sign of bone cancer and if it has spread to the lungs, it can cause breathlessness and cough.
Tests to detect bone cancers
Physicians initially conduct history and physical examination and may ask for one or a few of the tests, namely X-Ray, CT scans, MRIs, bone scans, PET-CT Scans and Biopsy with Immunohistochemistry.
Staging and Grading: It depends on the extent of the tumor, both locally and systemically. They are determined by Imaging Modalities while grading denotes the aggressiveness of the cancer determined histologically.
Treatment of Bone Cancer
Just as other cancers, the treatment options depend on the type and stage of cancer, and the overall health. It is best to let the consulting oncologist guide in understanding the health condition and the favored treatment.
With surgery, the tumor can be removed along with some tissue around the tumor. The lost bones are replaced with bone from other parts or with plastic or metal. In some cases, a long bone may need surgery and sometimes, amputation, though this is rare.
During chemotherapy, combinations of medicines are administered intravenously. It is either administered after the surgery to destroy the micro metastatic cells shed from the tumor, to reduce the chances of recurrence. It is also given prior to surgery to reduce the bulk of the tumor.
Recently, Targeted Therapy and Immunotherapy have changed the treatment landscape. In Radiation Therapy, high-powered energy beams are used to kill the cancer cells in surgically inoperable cases and sometimes, after the surgery.
It is important to ensure the symptoms are under control and they should consult clinical experts at the earliest to avoid any deterioration of health.

Authored by:
Dr. Sarat Chandra Pingali, Surgical Oncology, HCG Cancer Hospital, Vijayawada