FRIDAY, July 9 (HealthDay News) -- People with specific antibodies may develop both cancer and a certain type of scleroderma -- an incurable autoimmune disease -- at nearly the same time, new research finds. The finding, from a small study of 23 patients, hints at a possible link between cancer and autoimmune disorders.

Scleroderma is a condition that causes scar tissue to build up in the skin and in major organ systems. Some people with scleroderma seem also to be at increased risk for cancer.

"Our research adds more to the discussion about whether cancer and autoimmune diseases are related and whether cancer may be a trigger for scleroderma," study lead author Dr. Ami A. Shah, an assistant professor of medicine in the rheumatology division at the Johns Hopkins University School of Medicine, said in a university news release.

Shah and colleagues analyzed blood and tumor samples from 23 patients with both scleroderma and cancer. Patients with antibodies called anti-RNA polymerase I/III had the most closely related onset of cancer and scleroderma - both diseases developed within two years of one another.

Similar results appeared in another subset of patients, although they did not test positive for any known autoimmune antibodies. The researchers speculated that they may have immune markers in their blood that have not yet been discovered.

The study appears online in the journal Arthritis & Rheumatism.

The reasons for the apparent association between scleroderma and cancer aren't known, and it's not clear whether cancer could be causing scleroderma or vice versa, Shah said. Among the theories:

• An immune response generated by the body to fight a tumor may trigger the development of scleroderma.
• Organ damage from scleroderma could increase the risk of cancer.
• Immune-suppressing drugs used to treat scleroderma could lead to cancer.

A number of other autoimmune disorders also appear to have a possible connection to cancer and this research could have implications for those diseases as well, Shah said.

More information

The U.S. National Institute of Arthritis and Musculoskeletal and Skin Diseases has more about scleroderma.