Spontaneous remission
Encyclopedia
Spontaneous healing, also called spontaneous remission or spontaneous regression, means an unexpected improvement or cure from a disease which usually is taking a different course. Both terms are mainly used for unexpected transient or final improvements in cancer. Spontaneous remissions concern cancers of the haematopoietic system (blood cancer, e.g. leukemia), while spontaneous regressions concern palpable tumors; however, both notions are often used interchangeably.

Definition

The spontaneous regression and remission from cancer
Cancer
Cancer , known medically as a malignant neoplasm, is a large group of different diseases, all involving unregulated cell growth. In cancer, cells divide and grow uncontrollably, forming malignant tumors, and invade nearby parts of the body. The cancer may also spread to more distant parts of the...

 was defined by Everson and Cole in their 1966 book ': "The partial or complete disappearance of a malignant tumour in the absence of all treatment, or in the presence of therapy which is considered inadequate to exert significant influence on neoplastic disease."

Frequency

It has long been assumed that spontaneous regressions, let alone cures, from cancer are rare phenomena, and that some forms of cancer are more prone to unexpected courses (melanoma
Melanoma
Melanoma is a malignant tumor of melanocytes. Melanocytes are cells that produce the dark pigment, melanin, which is responsible for the color of skin. They predominantly occur in skin, but are also found in other parts of the body, including the bowel and the eye...

, neuroblastoma
Neuroblastoma
Neuroblastoma is the most common extracranial solid cancer in childhood and the most common cancer in infancy, with an annual incidence of about 650 cases per year in the US , and 100 cases per year in the UK . Close to 50 percent of neuroblastoma cases occur in children younger than two years old...

, lymphoma
Lymphoma
Lymphoma is a cancer in the lymphatic cells of the immune system. Typically, lymphomas present as a solid tumor of lymphoid cells. Treatment might involve chemotherapy and in some cases radiotherapy and/or bone marrow transplantation, and can be curable depending on the histology, type, and stage...

) than others (carcinoma
Carcinoma
Carcinoma is the medical term for the most common type of cancer occurring in humans. Put simply, a carcinoma is a cancer that begins in a tissue that lines the inner or outer surfaces of the body, and that generally arises from cells originating in the endodermal or ectodermal germ layer during...

). Frequency was estimated to be about 1 in 100,000 cancers; however, in reality this ratio might be largely under- or overestimated. For one, not all cases of spontaneous regression can be apprehended, either because the case was not well documented or the physician was not willing or literate enough to publish, or simply because the patient did not show up in a clinic any more. On the other hand, for the past 100 years almost all cancer patients have been treated in one way or the other, such that the influence of treatment cannot always be excluded.

At least for small tumors the frequency of spontaneous regression most likely was drastically underrated. In a carefully designed study on mammography it was found that 22% of all breast cancer cases underwent spontaneous regression. Searching for 'cancer AND (spontaneous AND (regression OR remission))' in the database PubMed
PubMed
PubMed is a free database accessing primarily the MEDLINE database of references and abstracts on life sciences and biomedical topics. The United States National Library of Medicine at the National Institutes of Health maintains the database as part of the Entrez information retrieval system...

 retrieves about 10000 publications.

Cause

Everson and Cole offered as explanation for spontaneous regression from cancer: "In many of the collected cases ... it must be acknowledged that the factors or mechanisms responsible for spontaneous regression are obscure or unknown in the light of present knowledge. However, in some of the cases, available knowledge permits one to infer that hormonal influences probably were important. ... In other cases, the protocols strongly suggest that an immune mechanism was responsible". Challis and Stam in 1989, even more at a loss, survey "In summary, we are left to conclude that, although a great number of interesting and unusual cases continue to be published annually, there is still little conclusive data that explains the occurrence of spontaneous regression.".

In medical circles sometimes apoptosis
Apoptosis
Apoptosis is the process of programmed cell death that may occur in multicellular organisms. Biochemical events lead to characteristic cell changes and death. These changes include blebbing, cell shrinkage, nuclear fragmentation, chromatin condensation, and chromosomal DNA fragmentation...

 (programmed cell death) or angiogenesis
Angiogenesis
Angiogenesis is the physiological process involving the growth of new blood vessels from pre-existing vessels. Though there has been some debate over terminology, vasculogenesis is the term used for spontaneous blood-vessel formation, and intussusception is the term for the formation of new blood...

(growth of new blood vessels) is discussed as "cause" of spontaneous regression. But both mechanisms need appropriate biochemical triggers and can not be caused on their own. To the contrary, in many cancer cells apoptosis is defective, angiogenesis is activated, both caused by mutations in cancer cells; cancer exists because both mechanisms are malfunctioning.

A great number, if not a majority of spontaneous regressions from cancer occurred after a feverish infection,. If this coincidence in time would be a causal connection, it should as well precipitate as prophylactic effect, i.e. feverish infections should lower the risk to develop cancer later. This could be confirmed recently by collecting epidemiological studies.

Reviews

Rohdenburg (1918) summarizes 185 spontaneous regressions, Fauvet reports 202 cases between 1960–1964, Boyd reports 98 cases in 1966, Cole und Everson described 176 cases between 1900–1960, Challis summarizes 489 cases 1900–1987, Brendon O'Regan and Caryle Hirschberg (Hirshberg) published a book on the subject in 1993.Uwe Hoboh, in a meta-analysis, investigated about 1000 cases.

Further reading


External links

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