WASHINGTON -- It started with flu-like symptoms that Michael Locher just couldn't shake. Then an egg-shaped lump ballooned on his jaw, and his doctor knew -- Locher was the latest victim in the nation's baffling rise in lymphoma.
Even as many other types of cancer have leveled off or even dropped, this mysterious immune-system cancer has been making a quiet but astounding rise; rates have nearly doubled since the 1970s.
Is diet to blame? Pesticides? Air pollution? Viruses? Obesity? Nobody knows.
Cancer experts are launching major studies worldwide to find what's behind this cancer's march.
But there is good news: Doctors are testing highly promising new immunotherapies for the worst type, non-Hodgkins lymphoma. They include a potent -- but still experimental -- "monoclonal antibody" called Bexxar that carries radiation straight to cancer cells to zap them without hurting healthy tissue.
"This is just amazing," said Locher, a New York City Transit Authority engineer whose tumors vanished last fall after he took Bexxar in a medical experiment.
"The results have looked very, very promising," says Dr. Wyndham Wilson of the National Cancer Institute. "What's even more exciting is that there are now a whole number of different monoclonal antibodies coming forward" to attack numerous varieties of lymphoma.
NCI scientists are also developing experimental vaccines customized to patients' cancers in hopes of preventing hidden lymphoma cells from staging a comeback after chemotherapy.
Some 62,300 Americans will be diagnosed this year with lymphoma, in which vital immune cells stored in the lymph system become malignant. More than 27,000 lymphoma patients will die this year.
It's a cancer that doesn't make many headlines -- lung, prostate, breast and colon cancer strike more often. Yet some 450,000 Americans are estimated to already be living with lymphoma, one of the few cancers still rising. Unlike many other cancers, doctors can offer no advice on preventing lymphoma and have no early-detection tests.
About 7,400 of the new cases will be the often curable Hodgkin's disease.
The rest are non-Hodgkin's lymphoma, a catchall term that encompasses some 30 cancer subtypes whose prognosis and treatment all differ. Some are so slow-growing that patients survive many years, cycling between therapy and remission and yet more therapy. Others are highly aggressive and rapidly fatal. Still others fall in between.
Non-Hodgkin's lymphoma is the type rising so dramatically, not just here but in most industrialized countries, said Dr. Marshall Lichtman of the Leukemia & Lymphoma Society.
The AIDS virus caused some of the increase. Lymphoma is much more common in people with weakened immune systems.
The list of other suspects is long but unproven: herbicides, pesticides, benzene-polluted air, the Epstein-Barr virus. One recent study suggests being overweight increases risk. A new theory that sunburns lower immune function has scientists considering a lymphoma link.
On the flip side, University of California at San Francisco scientists recently discovered people with bad allergies might be at lower risk. The theory is that allergies might indicate a vigorous immune system that can handle lymphoma.
"The immune perturbations that give you lymphoma are pretty complex. This is not going to be the equivalent of lung cancer and smoking -- it's going to be a little more subtle to tease out," cautions NCI epidemiologist Patricia Hartge.
The big news is in experimental immunotherapy -- genetically engineering cells called monoclonal antibodies that seek out cancer and trigger the immune system to attack it.
One, called Rituxan, already is sold, targeting lymphomas that carry an antigen called CD20. Now scientists are developing monoclonal antibodies to target CD30, CD22 and CD25 antigens -- and thus treat more types of lymphoma.
Bexxar is poised to become the first radiation-tagged monoclonal antibody, carrying radioactive iodine to zap lymphoma cells. Manufacturer Coulter Pharmaceutical Inc. will soon seek government approval for Bexxar to treat certain "low grade" lymphomas that relapse after chemotherapy; doctors now are studying to find out whether it works against other types.
