Certain types of cancer get publicity whenever popular personalities succumb to them. Two examples are anal (Farrah Fawcett) and pancreatic (Patrick Swayze) cancer. However, few people see any information on the most obscure forms. Here are three of the rarest types of cancer.
Synovial Sarcoma
According to the National Cancer Institute, this disease is a cancer of the body’s muscle, fat, fibrous tissue, blood vessels and other supporting tissue. It also strikes the lining of joints like the knee and elbow.
Experts report that this rare cancer is a disease of young adults. Almost one third of patients are younger than 20 and are more likely to be male than female. The median age is 26.5. Researchers report no specific cause for synovial sarcoma but believe genetic factors are important.
Around half of synovial sarcomas occur in the legs, particularly in the knees. The arm is also a frequent site. Around half of individuals affected experience metastasized cancer that has spread to the lungs, bone marrow or lymph nodes.
Because this is a slow-growing cancer, patients might not initially notice any symptoms. Typical signs include swelling or a mass that’s either painful or tender. The tumor might press on nerves and cause numbness. The symptoms are sometimes erroneously linked to arthritis or bursitis.
Surgery is the most common treatment for synovial sarcoma, depending upon staging and each patient’s circumstances. When an initial surgery doesn’t yield cancer-free margins at the borders, the patient might need a second operation. Doctors also use radiation therapy aimed directly at the tumor as well as inserted radioactive material.
Gastrointestinal Stromal Tumors (GISTs)
GISTs are the products of a rare type of cancer that begins in interstitials cells of Cajal (ICCs). These are special cells located in the wall of the human gastrointestinal (GI) tract and are part of the body’s autonomic nervous system, eMedicine reports. The gut gets its cues to digest food via signals from ICCs. Between 50 and 70 percent of these tumors start in the stomach.
Only around 10 to 20 individuals out of a million develop GISTs per year. The tumors can occur anywhere in the GI tract. Men are more likely than women to develop this type of cancer, which typically occurs between 55 and 65. The overall survival rate varies widely, from 28 to 60 percent.
Large tumors can cause complications like bowel obstruction or perforation and GI hemorrhages. However, doctors detect many GISTs before any discernible symptoms. They believe the cause is hereditary for a minority of patients. No symptoms point specifically to the illness.
The only effective medical treatment for a GIST is chemotherapy using the medication imatinib myesylate. The only chance to cure this type of cancer is surgery to remove it. Sometimes doctors debulk large tumors before the patient starts chemotherapy.
Merkel Cell Carcinoma
This rare condition is a fast-growing skin cancer. It occurs either on or under the skin. Experts believe it starts in neuroendocrine cells known as Merkel cells, according to the National Cancer Institute.
Doctors diagnose only around 1,200 new cases in the United States every year. The average age of diagnosis is 69. The disease occurs more often in white patients than in those of other racial or ethnic backgrounds.
While the exact cause of Merkel Cell carcinoma remains elusive, experts have linked it to sun exposure plus suppression of the body’s immune system. The primary symptom is the appearance of a firm, painless lump that might look like a cyst that doesn’t move. It can be red, pink or blue-violet.
The most common treatment for this rare type of cancer is surgery that removes a large border around the tumor. As an alternative, some doctors use Mohs micrographic surgery to remove and study individual layers of tissue. Surgeons sometimes remove the patient’s lymph nodes and recommend radiation therapy to ward off recurrence. When the cancer is not accessible to radiation, the remaining option is chemotherapy.
The prognosis for this type of rare cancer depends largely on the initial stage of the disease and size of the tumor.
Sources:
National Cancer Institute synovial sarcoma section
eMedicine site
National Cancer Institute Merkel cell fact sheet
Reference:
- National Cancer Institute synovial sarcoma section
- eMedicine site
- National Cancer Institute Merkel cell fact sheet
