Cancer
The Nature of Cancer
Lazy Cells Upset Traditional Ideas
Dr. William Woods, a neuroblastoma expert at the Aflac Cancer Center of Emory University in Atlanta, cited a powerful lesson: “The theory that one can pick up all cancers early and have the outcome good is not correct,” he said. “It certainly is not correct for neuroblastoma.”
But some are asking whether the neuroblastoma case is the exception or the rule. That is a conundrum that hinges on an emerging and startling view of the very nature of cancer.
Over the last few years, investigators have found more and more hints that cancer is not what they always thought it was. The traditional view was that cancerous cells looked aberrant under a microscope, grew in an uncontrolled fashion and, in most cases, killed.
Now, though, researchers understand that some cancers are indolent - so indolent, in fact, that they will never grow large enough in the patient’s lifetime to cause medical problems. Still others look like cancers under the microscope and have growth patterns in the lab that are typical of deadly tumors but can stop growing on their own and revert to normal tissue.
At the same time, there are more screening tests, and they are increasingly sensitive, finding cancers at earlier stages. That leaves doctors with a problem. The earlier they detect cells that look cancerous, the less certain they can be of how dangerous they are.
“The whole issue of diagnosis is based on visual criteria,” said Dr. Evan R. Farmer, a dermatologist, skin pathologist and the dean of Eastern Virginia Medical School. “But with cancer, you are talking about what happens biologically. If it metastasizes and kills the patient, then you know it’s
cancer. If it doesn’t metastasize, then you don’t know if it is or isn’t cancer.
“Maybe you didn’t wait long enough or maybe you treated it successfully or maybe it had the capacity to metastasize but you removed it or maybe it looked like cancer and you called it cancer. But in fact it didn’t have the ability to metastasize.”
Medical experts say they are agonizing over the screening questions.
“This is both an intellectual and an emotional debate,” said Dr. Isra Levy, a cancer specialist at the Canadian Medical Association, who participated in the study of neuroblastoma screening. “The issues are all legitimate issues, and they are very, very difficult. We are dealing in a world where certainty
is desirable, but it isn’t there.” Even the names given to some tumors hint at their ambiguous nature. There are “incidentalomas,” adrenal gland tumors of unknown significance that began turning up in increasing numbers when people had C.T. scans or M.R.I.’s for other conditions. Medical specialists do not know whether they should be removed or left alone, but they do know that lethal adrenalcancers are far too rare for many of those tiny tumors to be dangerous.
In cervical cancer, the most common abnormality found with Pap tests is called “atypical squamous cells of unknown significance.”
“The name tells you how much we know about its natural history,” Dr. Barnett Kramer, director of the Office of Disease Prevention at the National Institutes of Health, said. The condition’s significance is unclear, but to be safe, doctors remove the abnormal cells.
Experts may not even agree about whether a cell sample looks abnormal, as Dr. Farmer learned a few years ago. He and his colleagues asked expert pathologists to submit what they considered classic slides of skin tumors that were either malignant or not, examples that these specialists thought
were so clear that they could be used in a textbook. Dr. Farmer and his team sent the slides of cells from 37 patients to eight leading pathologists. Those experts had agreed to decide whether the tumors were cancerous or normal or whether the category was unclear.
They looked for a disordered growth pattern in the tumor tissue. They examined the individual cells, looking for irregular shapes and enlarged nuclei. In just 11 of the 37 tumors did all the experts come to the same conclusion about what they were seeing.
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Loretta drlanphier@oasisadvancedwellness.com