THE FORGOTTEN CANCER – SARCOMA.
By Dr.Sadiya Khan, Intern, Bangalore.
“Cancer is an expansionist disease; it invades through tissues, sets up colonies in hostile landscapes, seeking “sanctuary” in one organ and then immigrating to another. It lives desperately, inventively, fiercely, territorially, cannily, and defensively—at times, as if teaching us how to survive. To confront cancer is to encounter a parallel species, one perhaps more adapted to survival than even we are.” – The Emperor of All Maladies by Siddhartha Mukherjee.
July marks Sarcoma Awareness Month. Symbolised by the yellow ribbon, Sarcomas are a rare and heterogenous group of malignant tumours of mesenchymal origin. They can develop in the bones and soft tissues like fat,muscles, nerves, blood vessels, and fibrous tissues. Sarcomas can affect people of all ages.
There are 2 major types of sarcomas :
- Bone sarcomas- usually found in children. Osteosarcoma is the most common type of primary bone cancer.
Other types of bone tumors include:
- Clear cell chondrosarcoma
- Classic osteosarcoma
- Ewing’s sarcoma
- Giant cell tumor of bone
- Intraosseous osteosarcoma
- Malignant fibrous histiocytoma (MFH)
- Mesenchymal chondrosarcoma
- Periosteal osteosarcoma
- Small cell osteosarcoma
- Soft tissue sarcomas- most commonly found in the arms, legs, chest or abdomen. In children, rhabdomyosarcoma is the most common subtype of soft tissue sarcomas. The various subtypes of soft tissue sarcomas are:
- Undifferentiated pleomorphic sarcoma
- Synovial sarcoma
- Clear cell sarcoma
- Gastrointestinal stromal tumour
The etiology of most sarcomas remains unknown. Most of the times, sarcomas occur sporadically and can be due to various genetic and environmental factors. Environmental factors that have been associated with soft tissue sarcomas include radiation therapy and exposure to certain chemicals including vinyl chloride, arsenic, and thorium dioxide. Long standing lymphoedema is also a risk factor for certain subtypes of sarcoma.
Soft tissue sarcomas occur with greater frequency in people or families that have rare genetic cancer-predisposing syndromes such as hereditary retinoblastoma, Li-Fraumeni syndrome, neurofibromatosis type I, familial adenomatous polyposis (FAP), tuberous sclerosis. These disorders are associated with specific genes that are shown to increase the risk of specific forms of cancer.
Sarcomas can present as a painless lump or a swelling. Some soft tissue sarcomas can present with symproms when they grow and press on neighbouring structures.
Bone sarcomas can commonly present as pain/ swelling in an arm or leg, fever, limited range of motion in a joint and fractures with no apparent cause.
Diagnosis of sarcomas is often delayed due to the lack of awareness of signs and symptoms among the public and limited experience of the healthcare professionals. Delay may allow the development of advanced disease, which is not amenable to curative surgical resection. The five-year overall survival for soft tissue and bone sarcomas remains poor at around 50–60%.
About 20% of sarcomas can be treated by surgery and an additional 30% can be treated by surgery with chemotherapy/radiation. Treatment depends on the grade of the tumor and degree of metastasis. However,sarcomas can be resistant hence, the need for breakthroughs in research on new and more effective therapeutic approaches to save the lives of countess children and adults.
Sarcoma awareness month aims to increase awareness about this forgotten cancer among the public and health care professionals in order to aid timely diagnosis. All the medical students and graduates must be equipped to detect and investigate suspicious soft tissue and bony masses before it is too late. Medical curriculums should be designed to sensitise students to the ordeals faced by patients suffering from rare conditions and importance of cancer research. Governments must also work on increase funding for research and reduce disparities in access to treatment.