Spontaneous Regression Of Malignant Tumors Research Articles

MECHANISMS OF SPONTANEOUS REGRESSION OF MALIGNANT TUMORS IN INFLAMMATION

Annotation: The study of the mechanisms of spontaneous regression of malignant tumors is a topical issue of our century. Disclosure of the pathogenesis of regression will allow progress in the treatment of such diseases. The article discusses the mechanisms of regression of malignant tumors in inflammation, discloses the role of bacteria in this issue, and analyzes the possible mechanism of immunity sensitization in such diseases. The review of immune mechanisms was carried out on the basis of these articles, which studied the Coli toxin, BCG vaccine. The results showed the effectiveness of the use of these funds in the treatment of cancer patients. The possibilities of using bacteria for the transfer of drugs to the tumor area and their production of cytokines are also described. In addition, the correlation between the time of onset of inflammation and regression of tumor formation was analyzed. The main antitumor compounds and substances (IL-1, IL-12, TNF family, LIGHT and CCL21) were also noted, their effect on tumor cells and their role in the regression of malignant tumors was described. As a result, it was concluded that bacteria increase the ability of the immune system to recognize and attack tumor cells, however, the individual characteristics of the reactivity of the human immune system should be taken into account before such therapy.

A case of rectal tumor in which the shape altered with regression in short period

BackgroundHistological regression of solid tumors in adults receiving no treatment is rare. Specifically, spontaneous partial and complete regression of colorectal cancers account for less than 2% of such cases and those without metastasis are exceedingly rare.Case presentationA 60-year-old male underwent total colonoscopy following a positive fecal occult blood test at the referring hospital. A flat elevated lesion with central reddish depression, 10 mm in diameter, was detected in the lower rectum. Biopsy results from the referring hospital showed a well-differentiated adenocarcinoma and the patient was referred to our hospital for diagnosis and treatment. Preoperative colonoscopy was performed to determine the therapeutic strategy; however, we found only scar tissue and there were no endoscopic features to suggest malignancy. Biopsy from the scar revealed normal rectal mucosa and we performed diagnostic endoscopic submucosal resection with a ligation device (ESMR-L) one week later. The resected specimen showed a 1 mm well-differentiated adenocarcinoma with low-grade atypia and no lymphovascular invasion. The macroscopic type was 0-IIb, the depth of invasion was intramucosal, and the vertical and lateral margins were negative. There has been no evidence of recurrence for 18 months following treatment.ConclusionWe report a case of a rectal tumor showing regression over a short period without treatment. Spontaneous regression of malignant tumors is a rare and unexplained phenomenon. Further research and understanding of the mechanism holds the key for treatment and prevention of cancer in the future.

Small-cell Lung Cancer Exhibiting Spontaneous Regression

A 56-year-old woman was admitted to our hospital because a chest X-ray and thoracic computed tomography (CT) scan revealed a heterogeneous tumor in the middle mediastinum during a visit to a nearby clinic for a consultation regarding a persistent cough and body weight loss. However, the tumor spontaneously decreased on thoracic CT performed on admission. Subsequently, a biopsy of the tumor using video-assisted thoracoscopy was performed. The pathological findings disclosed the tumor to be small-cell lung cancer with infiltration of CD8-positive T-cells exhibiting spontaneous regression. Cell-mediated immunity, including CD8-positive T-cells, may have relevance to the spontaneous regression of malignant tumors.

Spontaneous regression of malignant tumors: Importance of the immune system and other factors (Review).

It has been established that malignant tumors as well as metastases, of almost all histological types, can regress spontaneously although certain histological types regress more frequently than others. Various causes thereof include apoptosis, the immune system and particular conditions of the tumor microenvironment. The action of the genome in the regression of tumors is not clear, but some data, apart from those of apoptosis, support its involvement. The hypothesis that the immune system exhibits variations in efficacy, even to a marked extent, in determining partial or total regression of tumors appears to be plausible. Such variable efficacy may be supported by blockage of growth and the proliferation of cancer cells at the level of the tumor microenvironment, the intervention of various factors such as inhibitors of metalloproteinases and angiogenesis, and the absence or scarcity of particular proteins. The consequence of such a blockage would be a relative increase in the number of natural killer cells and other elements involved in the immune system in relation to the number of circulating cancer cells in the blood. A relative increase in the number of elements of the immune system is more effective than an absolute increase, since an absolute increase is able to stimulate, as frequently occurs for feedback in biological equilibria, inhibitor receptors that reduce the efficacy of the same elements (mainly natural killer and CD8(+) T cells). Such an increase in the efficacy of the immune system can lead, at least in certain cases, to the so-called spontaneous regression of malignant tumors. Clinical practice has demonstrated that metastases are less frequent in patients with renal carcinoma undergoing hemodialysis compared with patients with renal carcinoma not on hemodialysis. This finding can be interpreted, in correlation with the blockage of cancer cells in tissues, as a consequence of a partial blockage of metastatic cancer cells at the level of the dialytic membrane, with a subsequent increase in the relative efficacy of the immune system.

Restoration of expression of MHC class I molecule in Walker 256 tumor in growth dynamics in Brattleboro rats

11 Establishing possible mechanisms influencing the growth and regression of malignant neoplasias is the key problem of modern experimental and clinical oncology. It is known that realization of these mecha� nisms includes both innate and adaptive immunity; natural killer cells (NK cells), macrophages, dendritic cells, various cytokines, and specific cytotoxic T cells. However, spontaneous regression of malignant tumors occurs very rarely, which is associated primarily with the “avoidance” of their recognition by the immune system. One of the causes of this phenomenon may be a low level of expression of the major histocompatibil� ity complex (MHC) class I antigens, which are required for presenting oncoantigens to cytotoxic T cells and/or disturbance of the regulatory mechanisms of their expression [1]. Our earlier study demonstrated complete regression of Walker 256 carcinosarcoma, a tumor that causes death of control WAG rats on day 25–27 after transplantation, in Brattleboro rats with genetically deficient synthesis of arginine–vasopressin (AVP) in the hypothalamus [2]. AVP deficiency is obviously a key condition that determines the regression of this tumor in Brattleboro rats. Apparently, the observed effect was not deter� mined by the rapid hormonal effect of AVP. According to published data, chronic systemic administration of AVP to Brattleboro rats normalizes the disturbed water–salt balance in them but has no effect on the increased activity of NK cells observed in these rats [3]. Since innate and adaptive immunity are related, it can be assumed that the enhancement of innate anti� tumor immunity in Brattleboro rats induces the devel� opment of specific immune reactions. This may be expressed as an increase in the efficiency of recogni� tion of transformed cells. The fact that a repeated transplantation of Walker 256 to Brattleboro rats did not result in tumor development allowed us to assume the involvement of adaptive immunity in the realiza� tion of this phenomenon.

自然退縮した進行下咽頭癌例

Spontaneous regression of any malignant tumor is a rare event, occurring in about 1 per 60, 000-100, 000 among the total number of cases of malignant tumor. We report a case of the spontaneous regression of the hypopharyngeal carcinoma with multiple pulmonary metastases.The patient was a 75-year-old man who complained of dysphagia. He was found to have squamous cell carcinoma of the hypopharynx with multiple pulmonary metastases. Since his airway was almost occluded by the tumor, tracheostomy was performed urgently. About two weeks later, while preparing for chemotherapy for the tumor, the primary tumor began to reduce without any treatment. Subsequently not only the primary tumor but also metastatic lesion continued to reduce spontaneously, and about four months later, they disappeared completely.It is thought that elucidation of the mechanisms of spontaneous regression of malignant tumors could possibly lead to a more effective therapy for cancer.

Spontaneous regression of hepatocellular carcinoma. A case study

A Chinese patient with documented hepatocellular carcinoma (HCC) satisfied the criteria of Everson and Cole for spontaneous regression of malignant tumors. Subsequently he survived a tumor-free period of at least 13 years. During the period of regression, shrinkage of liver coincided with a rise of SGOT to a level comparable to that reported for patients with liver cancer during hepatic arterial ligation and cytotoxic therapy. Postregression liver biopsy from the site of the previous tumor revealed relatively uninflamed HBsAg-positive tissue without dysplasia. The case provided the positive end of the survival spectrum in HCC, evidence that regression of HCC might occur by involution rather than maturation, and histologic data suggesting that regressed HCC might be replaced by surrounding tissue instead of leaving behind dysplasia.

Spontaneous regression of malignant tumors: Report of a twelve-year spontaneous complete regression of anextensive fibrosarcoma, with speculations about regression and dormancy

<h2>Summary</h2> <ul>o<li>1.Malignant tumors frequently show fluctuation in rate of growth. Some have periods of very slow and then rapid growth. Some are slow tometastasize or the metastases may be dormant for many years. There are a few proved cases of malignant tumors that have completely regressed without any therapy.</li><li>2.Most of the cases reported as "spontaneous cures" cannot be accepted when examinedcritically. To aid in the segregation of cases of complete spontaneous regression, a list of criteria is proposed.</li><li>3.A case is reported of a girl who had an extensive ftbrosarcoma when five months of age, received no treatment and is now entirely well at thirteen years of age.</li><li>4.A list of possible factors concerned in spontaneous regression of malignant tumors is presented.</li><li>5.The various theories which have been suggested to explain late recurrence and metastasis are discussed.</li><li>6.The variability of rate of growth of all types of malignant tumors must be considered when evaluating a particular type of therapy or inestimating the prognosis.</li></ul>

FEVER THERAPY OF MYCOSIS FUNGOIDES

Occasional cases of spontaneous regression of malignant tumors have been reported following attacks of acute infectious disease. In line with these observations, cases of mycosis fungoides, which disease in its later stage assumes the character of a malignant neoplasm, have been reported improved, indeed cured, following attacks of an acute febrile condition. From published reports1of spontaneous regression of neoplasms it appears that such regression has occurred following incomplete surgical removal of the tumor, during acute febrile processes and following the application of heat, frequently in connection with some profound alteration in the metabolic processes of the organism, such as cachexia, artificial menopause or the puerperium. Of these circumstances, acute systemic infection is pertinent to this presentation. The majority of cases of spontaneous regression of neoplasms following an acute infection have occurred after an attack of erysipelas.2Such regressions have also occurred after smallpox, pneumonia, malaria and acute