Ask Dr. Gary: Rare fibrosis difficult to treat

Retroperitoneal fibrosis affects very few New Zealanders, but can teach us a lot about how the body's natural processes can go off track. I hadn't met anyone with it until recently but they're happy for me to discuss it in this column, as there might be others who could benefit from the knowledge.

Retroperitoneal fibrosis is thought to affect one in 500,000 people. It starts off in most people with back pain that comes in waves, but eventually becomes chronic. In many cases patients or their GPs try analgesics for what they assume is a bad back.

The pain can continue for weeks or months, but sooner or later they start having urinary problems, such as kidney infections or blood in the urine. They often end up in an emergency department, where they might get a CT scan to look for something common, such as a kidney stone. The scan shows a large mass in the back of the abdomen (called the retroperitoneum).

A cancer workup ensues and patients get scared as renal cancers often have a poor prognosis. Biopsies are performed using long needles under ultrasound or CT guidance, but results are often inconclusive, showing areas of scarring, but no cancer cells. The cancer hunt continues, sometimes with open biopsies done through large surgical incisions.

Eventually the diagnosis is made: retroperitoneal fibrosis. Patients are initially reassured they don't have cancer, but when they learn how little doctors know about retroperitoneal fibrosis, the worries begin again.

Retroperitoneal fibrosis can occur as a side effect of several different medicines, as a symptom of a cancer hiding somewhere else in the body, as a surgical complication, or as an autoimmune disease where the body attacks its own cells.

But usually, it seems to occur for no reason at all. Doctors call that''idiopathic''. The cancer associated types of retroperitoneal fibrosis typically cause death in six to 12 months. The other kinds might persist one's whole life and never kill the patient.

Every case is different and unpredictable. Retroperitoneal fibrosis is a process of indiscriminate scarring in the back of the abdomen, encroaching upon and eventually pinching off the patient's ureters.

Urine backs up into the kidneys, causing pain and infection, and eventually kidney failure. The fibrosis, or scarring, continues inexorably, squeezing the kidney, and encircling and compressing the aorta which supplies blood to

the gut, pelvis and legs. Patients can end up on dialysis, paralysed, or even dead. Or none of these things may happen as the fibrotic process can start and stop.

Treatment is in its infancy. Doctors typically throw high-dose steroids at the condition for months to suppress the body's immune system, or use immunotherapies borrowed from the world of rheumatoid arthritis and lupus to do the same.

They can physically stent open blocked ureters from the inside out, or stick tubes through the back into the kidneys to allow them to drain freely. Surgical debulking is sometimes necessary to cut scar tissue off important organs.

Breast cancer therapies such as tamoxifen have had some success. No one's exactly sure how how these things work in RF. But in many cases, they do work. By work I don't mean ''cure'',Imean ''suppress''. Whatever the therapy, patients often need lifelong monitoring with CT or MRI to confirm the disease is kept in check.

Even if successfully treated, patients are left waiting, wondering if that soreness they feel is their disease scarring away at their insides, or just a sore back.

If you know of anyone with retroperitoneal fibrosis, or a Kiwi support group, send me an email, and I'll forward it. It makes it easier to bear a disease knowing you're not the only one in the world with it.