A person comes down with a terrible disease. The doctors give up all hope. Then, suddenly, the disease is gone. It's a great soap opera plot, but it can actually happen in real life. The question is, how?
Spontaneous remission, also known as spontaneous healing, is downplayed by the medical community. This is not due to some evil conspiracy. It's true that some doctors don't believe in the phenomenon — at least not when it comes to certain diseases — but most just try to discourage people from clinging to false hope, and, more urgently, from clinging to false cures. The internet being what it is, sites promote everything from ginseng to positive thinking as ways to bring about "spontaneous" remission. While few of these treatments do any physical harm, siphoning off money and energy from sick people is something to be frowned on.
Some professionals aren't fond of the word "spontaneous." They believe there has to be a mechanism behind this regression, especially since some cancers seem to go into regression more readily than others. Five types of cancer, renal cell carcinoma, leukemia and lymphoma, neuroblastoma, carcinoma of breast and melanoma, are relatively prone to seemingly causeless remission. Other types of cancer, like pancreatic cancer, only rarely go into spontaneous remission, and the few cases that have been reported may have involved patients who were simply misdiagnosed.
Finally, "spontaneous remission" is the popular term, but a more accurate term is "spontaneous regression." While some cancers go away, never to return, it's more common for cancer patients to spontaneously improve for a while, only to have the cancer come back and progress along its usual course. Even a temporary regression can give a patient extra years of life, or at the very least a dramatic improvement in the quality of their life. All oncologists hope for their patients to get well. They just don't count on it happening suddenly and without treatment.
Doctors are trying to get rid of the "spontaneous" part of spontaneous remission. This isn't because they have a driving need to disprove the miraculous. What they want is to turn the miraculous into the mundane. If there is some kind of mechanism that can be used to fight back cancer, finding and recreating that mechanism in every patient would save countless lives. Oncology is a science that's heavy on painful procedures like chemotherapy and surgery. Finding a method of treatment that's so subtle patients don't even notice it would in and of itself be giant leap forward in terms of care.
For now, the term "spontaneous" has to stay. No one knows what causes remission or regression. Many people have made guesses. One study lists the extensive ideas:
The prevalent hypotheses regarding mechanisms leading to spontaneous regression include the immunological response in the host as the most important factor. Other mechanisms causing spontaneous regression include increased apoptosis and necrosis, epigenetic modifications, hormonal responses, role of oncogenes and tumoral suppressors, cytokines and growth factors, and psychological mechanisms.
That leaves a lot of wiggle room.
There are a few solid correlations. One confirmed case of pancreatic cancer went into a brief but noticeable regression after an infection left a patient with a high fever. "Febrile infection" has been found to coincide with regression and remission in a number of other cancer cases. Some publications suggest revisiting controlled fevers as a method of bringing on an immune response that could battle cancer.
There are some studies that suggest spontaneous remission and regression happen more often than the literature suggests. Existing surveys acknowledge that there are probably a lot of cases out there that haven't been reported because the physician assumed misdiagnosis, didn't want to write the case up, or because the patient felt better and stopped treatment.
A couple of studies have shown that spontaneous remission might be happening in a significant percentage of cases. One study followed people with one or several solar keratoses for 12 months and noted that a third of them underwent spontaneous remission. A solar keratosis isn't cancer; it's a callus-like growth on the skin, caused by sun damage. While not dangerous on its own, a solar keratosis is relatively likely to turn cancerous. The fact that it can heal, seemingly without cause, gives us reason to believe that other kinds of growths can heal spontaneously as well.
The most dramatic study dealing with spontaneous regression, was completed in 2001. From 1996 to 2001, researchers invited women, aged 50 to 64, to regular breast cancer screenings. It would be unethical to form a control group by asking other women to hold off on such medical screenings, so there was no simultaneous group of women not getting screened. Instead, at the beginning of the study, the researchers asked women of the same age group who hadn't been screened for the previous six years to come in for a free screening. The cumulative amount of cancer in women who came in for regular screenings was higher than the cumulative amount of cancer in women who only got screened at the end of six years. The researchers found that "the cumulative incidence of invasive breast cancer remained 22% higher in the [regularly] screened group." Either regular screening caused breast cancer, or a large percentage of invasive breast cancers simply regressed without treatment.
It's an eerie thought, the idea that anyone could have cancer without ever knowing it. But it's also encouraging. Spontaneous remission could pave the way for very non-spontaneous treatment.
Images: National Cancer Institute.