Efforts to explain spontaneous regression of cancer

Spontaneous regression of hepatocellular carcinoma: a systematic review

OBJECTIVE

To estimate the actual frequency of spontaneous regression of hepatocellular carcinoma.

METHODS

A systematic review of the literature published during 1978-2007 has been carried out to identify randomized clinical trials of hepatocellular carcinoma that included a control arm receiving either placebo or best supportive care, and in which patients were followed prospectively for tumor response using predefined criteria. Data extraction was conducted independently by two investigators. A meta-analysis to provide a global estimation of regressions in the control arms was performed using an empiric Bayesian random-effects model.

RESULTS

We identified 16 cases of regression (including minor and partial responses) in 10 phase III clinical trials. The rate of spontaneous objective partial regression among patients with hepatocellular carcinoma was 0.406% [95% confidence interval: 0.067-1.043%].

CONCLUSION

Although very infrequent, spontaneous regression is not an extraordinary event among patients with hepatocellular carcinoma. Therefore, individual responses to any given therapy should be assessed with caution and this fact may be considered at the time of calculating sample size of pilot clinical trials of new agents.

Spontaneous regression of pulmonary metastases from breast angiosarcoma

Spontaneous regression of cancer is a rare phenomenon. We present a rare case of pulmonary metastases in a 72-year-old woman with metastatic breast angiosarcoma. She was diagnosed with a breast angiosarcoma in 2005 and underwent a total mastectomy and postoperative radiotherapy. Unfortunately, a year later she was found to have multiple lung and scalp metastases but in a view of her poor general fitness, she was not a candidate for chemotherapy and was kept on regular followup. Despite the absence of any treatment, the followup chest X-ray showed a significant reduction in the number and size of lung nodules and her scalp lesions regressed completely. Seven months after the diagnosis of metastatic disease, the nodules in her scalp remain controlled.

Spontaneous regression of hepatocellular carcinoma is possible and might have implications for future therapies

Hepatocellular carcinoma is a potentially challenging cancer with very high mortality. Medical therapies are generally ineffective in achieving complete remission, especially for aggressive types or for advanced stage cancers. Spontaneous regression of these tumors is a rare and fascinating phenomenon. We describe such a patient with spontaneous regression of a large multi-focal hepatocellular carcinoma, and present a comprehensive review of the reported cases with a special emphasis on potential regression mechanisms.

Hyperthermia on immune regulation: a temperature's story

Over the last decade the linkage between hyperthermia, heat shock proteins and fever with the body's immune system has been well investigated. The immunomodulatory function of hyperthermia has been found to be quite sensitively regulated by temperature, as different levels of heating can bring different modulatory effect on different sensitive targets. Understanding these intrinsic mechanisms could bring new inspirations on the design of clinical trials combining local tumor hyperthermia with immunotherapy in cancer patients. This review will attempt to tell the story about the effect of temperature on immune regulation, with special emphasis on the clinical application of hyperthermia and the feasibility of combining it with immunotherapy in the clinic.

Bacterial targeted tumour therapy-dawn of a new era

Original observation of patients' spontaneous recovery from advanced tumours after an infection or a "fever" inspired extensive research. As a result, Coley's toxin for the therapy of sarcomas and live Bacillus Calmette-Guerin (BCG) for bladder cancer were born. In addition, three genera of anaerobic bacteria have been shown to specifically and preferentially target solid tumours and cause significant tumour lyses. Initial research had focused on determining the best tumour colonizing bacteria, and assessing the therapeutic efficacy of different strategies either as a single or combination treatment modalities. However, although clinical trials were carried out as early as the 1960s, lack of complete tumour lyses with injection of Clostridial spores had limited their further use. Recent progress in the field has highlighted the rapid development of new tools for genetic manipulation of Clostridia which have otherwise been a hurdle for a long time, such as plasmid transformation using electroporation that bore the problems of inefficiency, instability and plasmid loss. A new Clostridium strain, C. novyi-NT made apathogenic by genetic modification, is under clinical trials. New genetic engineering tools, such as the group II intron has shown promise for genetic manipulation of bacteria and forecast the dawn of a new era for a tumour-targeted bacterial vector system for gene therapy of solid tumours. In this review we will discuss the potential of genetically manipulated bacteria that will usher in the new era of bacterial therapy for solid tumours, and highlight strategies and tools used to improve the bacterial oncolytic capability.

Spontaneous regression of lung metastasis from osteosarcoma: a case report

A case of spontaneous regression of a pulmonary metastasis from high-grade osteosarcoma is reported. The metastasis developed 5 years after chemotherapy and amputation for a distal femur osteosarcoma. The sarcomatous nature of the lesion was histologically confirmed. No treatment was attempted owing to the patient's refusal. The patient was followed up every 3 months and a spontaneous regression of the lesion was documented. Seven years after the diagnosis of lung metastases, no pulmonary nodules or other signs of relapse are present.

Merkel cell carcinoma: critical review with guidelines for multidisciplinary management

Merkel cell carcinoma (MCC) is a relatively rare cutaneous malignancy that occurs predominantly in the older white population. The incidence of MCC appears to have tripled during the past 20 years; an increase that is likely to continue because of the growing number of older Americans. The pathogenesis of MCC remains largely unknown. However, ultraviolet radiation and immunosuppression are likely to play a significant pathogenetic role. Many questions currently remain unanswered regarding the biologic behavior and optimal treatment of MCC. Large, prospective, randomized studies are not available and are unlikely to be performed because of the rarity of the disease. The objective of this review was to provide a comprehensive reference for MCC based on a critical evaluation of the current data. The authors investigated the importance of sentinel lymph node biopsy as a staging tool for MCC to assess the status of the regional lymph node basin and to determine the need for additional therapy to the lymph node basin. In an attempt to standardize prospective data collection with the intention to define prognostic indicators, the authors also present histopathologic profiles for primary MCC and sentinel lymph nodes. The controversies regarding the appropriate surgical approach to primary MCC, the use of adjuvant radiation therapy, and the effectiveness of adjuvant chemotherapy were examined critically. Finally, the authors have provided treatment guidelines based on the available evidence and their multidisciplinary experience.

Spontaneous regression of colorectal cancer: a review of cases from 1900 to 2005

INTRODUCTION

Spontaneous regression of cancer is an exceptional but well-documented biological event. Further understanding of this phenomenon and harnessing of the mechanisms involved will have significant preventative and therapeutic implications.

DISCUSSION

In this review, the literature of spontaneous regression of colon or rectal cancer is reviewed from 1965 to 2005 to update reviews by Everson et al., Boyd and Challis et al. By adding to these, the author reports the entire series of colorectal cancer, which underwent documented spontaneous regression from 1900 to 2005. The demographic and pathologic characteristics, the details of regression and the outcome of reported cases are presented and discussed. Special emphasis is placed on identifying possible causes hypothesized by authors for occurrence of regression. Possible mechanisms operating to affect these regressions are also discussed.

A case of spontaneous regression of small cell lung cancer with progression of paraneoplastic sensory neuropathy

We report here a rare case of small cell lung cancer (SCLC) accompanied by a partial spontaneous regression with a progression of paraneoplastic sensory neuropathy (PSN). A 55-year-old woman was admitted to our hospital with dry cough and progressive numbness in the distal extremities over 1 month. She was diagnosed as small cell lung cancer associated with paraneoplastic sensory neuropathy. About 1 month later, partial spontaneous regression of tumor with a progression of paraneoplastic sensory neuropathy was observed. A complete response was achieved through chemotherapy and concurrent radiotherapy. As the tumor size decreased, her neurological symptoms improved. A short interval between onset of PSN and the start of therapy may be essential for successful treatment for not only SCLC but also PSN.

Spontaneous regression of hepatocellular carcinoma

We report four patients with hepatocellular carcinoma (all men, with liver cirrhosis and hepatitis C virus infections) who showed spontaneous regression of the tumor. When the spontaneous regression occurred all of the patients were over age 67 years. They showed a rapid increase of serum alpha-fetoprotein levels just before the spontaneous regression of hepatocellular carcinoma. In all the patients, the alpha-fetoprotein level decreased to within normal limits and the tumor was partially to completely reduced in size. One patient revealed regression after bleeding of esophageal varices and blood transfusion. Another showed spontaneous regression after taking several complementary and alternative medicines. However, the mechanisms underlying this intriguing phenomenon remain unknown.

Ultrasonography and Fine-needle Aspiration Cytology in the Preoperative Evaluation of Melanoma Patients Eligible for Sentinel Node Biopsy

BACKGROUND

Ultrasonography with fine-needle aspiration cytology (FNAC) has proven to be a valuable diagnostic tool in the preoperative workup of patients with breast cancer or penile cancer eligible for sentinel lymph node biopsy. The aim of this study was to evaluate the use of this technique in the initial assessment of patients with primary cutaneous melanoma.

METHODS

A total of 107 patients with cutaneous melanoma eligible for sentinel node biopsy with clinically negative nodes were studied prospectively. Patients underwent ultrasonography of potentially involved basins and FNAC in case of a suspicious lymph node. The sentinel node procedure was omitted in patients with tumour-positive lymph nodes in lieu of lymph node dissection.

RESULTS

Ultrasonography with FNAC correctly identified disease preoperatively in two of the 107 patients (2%). Thirteen of the 22 patients (59%) with a suspicious node on ultrasonographic imaging but a tumour-negative fine-needle aspirate were shown to have involved nodes. Of the 85 patients with ultrasonographically normal nodes, 25 (29%) were shown to have metastases. Of the total of 43 involved basins, 16 contained metastases > 2 mm and 25 < or = 2 mm.

CONCLUSIONS

In our hands, the sensitivity and specificity of preoperative ultrasonography to detect lymph node involvement in patients with melanoma are 34% and 87%, respectively. In combination with FNAC, this is 4.7% and 100%, respectively. This yield is insufficient for this technique to be used as a routine diagnostic tool in the selection of patients eligible for sentinel node biopsy.

Spontaneous remission of small cell lung cancer: A case report and review in the literature

Spontaneous remission (SR) of cancer, especially of lung tumor, is a rare biological event. Only seven cases in which small cell lung cancer (SCLC) regressed spontaneously had been previously reported. We report here a rare case of complete SR of SCLC in an 86-year-old man. Paraneoplastic sensory neuronopathy (PSN) is a rare syndrome, which is associated with malignancy such as SCLC and starts with dysesthetic pain and numbness in the distal extremities, then spreading all four limbs and trunk causing severe sensory ataxia. In the previous reports, SR of SCLC is suggested to result from surgical trauma or PSN, which may be able to enhance anti-tumoral immunity. Our report is the case of SR of SCLC, without any therapies nor any invasive examinations. Although the reason of SR of SCLC in the present case is unknown, PSN could be one of the diagnosis by exclusion.

A case of spontaneous regression of hepatocellular carcinoma with multiple lung metastases

Spontaneous regression of hepatocellular carcinoma (HCC) is a rare phenomenon. We present herein the case of a patient with hepatocellular carcinoma with multiple lung metastases in whom malignancy spontaneously regressed after taking Pheliinus linteus Mycelium. A 79-year-old man consulted our hospital complaining of epigastric discomfort. Abdominal MRI and CT revealed a 3 cm diameter tumor in the liver, and chest CT showed numerous nodular lesions. The levels of alpha-fetoprotein (AFP) and protein induced by vitamin K deficiency or antagonist-II (PIVKA-II) were very high. We diagnosed HCC with multiple lung metastases, and no therapy was performed. Independently he took exact from Phellinus linteus Mycelium for one month, and 6 months later the tumors appeared to be in complete regression. The mechanism underlying this intriguing phenomenon remains unknown.

Spontaneous regression of cerebellar astrocytoma after subtotal resection

CASE REPORT

The authors report a child in whom residual cerebellar astrocytoma after surgical resection was documented on serial computed tomography scans to undergo gradual complete regression spontaneously over a period of 11 years. In this case, the time course of regression has been well documented.

CONCLUSION

The time course of regression may provide clues as to the underlying cause of this phenomenon.

From the archives of the AFIP: pilocytic astrocytoma: radiologic-pathologic correlation

Pilocytic astrocytoma is the most common pediatric central nervous system glial neoplasm and the most common pediatric cerebellar tumor. This tumor has a noteworthy benign biologic behavior that translates into an extremely high survival rate-94% at 10 years-that is by far the best of any glial tumor. Most patients present in the first 2 decades, and clinical symptoms and signs are usually of several months duration and directly related to the specific location of the tumor. The cerebellum, optic nerve and chiasm, and hypothalamic region are the most common locations, but the tumor can also be found in the cerebral hemisphere, ventricles, and spinal cord. Surgical resection is the treatment of choice for all tumors, except for those involving the optic pathway and hypothalamic region, which may be treated with radiation therapy and chemotherapy. Cross-sectional imaging often demonstrates a classic appearance: a cystic mass with an enhancing mural nodule. Less common appearances are quite nonspecific. Surrounding vasogenic edema is rarely present, and this feature provides a valuable clue to the correct diagnosis. Accurate interpretation of imaging studies plays an essential role in directing treatment of these tumors, particularly when they arise in the optic pathway of patients with neurofibromatosis type 1. Disseminated disease and recurrence are extremely rare.

Regression of hepatocellular carcinoma during vitamin K administration

An 85-year-old man with HCV infection and diabetes mellitus was diagnosed as having hepatocellular carcinoma (HCC, 13 cm in diameter) based on high serum alpha-fetoprotein (AFP), AFP-L3, and des-γ-carboxy prothrombin levels as well as typical enhancement pattern on contrast-enhanced CT. The patient did not receive any interventional treatments because of advanced age and the advanced stage of HCC. He chose to take vitamin K, which was reported to suppress the growth of HCC in vitro. Three months after starting vitamin K, all three tumor markers were normalized and HCC was markedly regressed, showing no enhancement in the early arterial phase on CT. Here we present the report describing the regression of HCC during the administration of vitamin K.

Clear cell hepatocellular carcinoma with spontaneous regression of primary and metastatic lesions

The prognosis of advanced hepatocellular carcinoma (HCC) tends to be poor. Spontaneous regression of this lesion is extremely rare. In this report, we describe a case of HCC which spontaneously regressed along with a metastatic lesion of the chest wall. A huge HCC in the right lobe, the largest diameter of which was about 15 x 12 cm, developed in a 72-year-old man. He and his family refused further treatment. Three months after the diagnosis, metastasis to the chest wall was detected. We prescribed a painkiller for him in order to alleviate chest pain. Fourteen months after the diagnosis, the tumor size of the primary lesion was downsized to 3 x 4 cm in diameter. A biopsy taken from the chest wall proved to be clear cell HCC (CHCC). Since then, the metastatic lesion has also disappeared. Here, we report this unusual histologically proven CHCC with literature reviews.

Regression of hepatocellular carcinoma spontaneous or herbal medicine related?

Hepatocellular carcinoma is one of the most common causes of death from cancer in Taiwan. Treatments for this disease include surgical resection, transcatheter arterial embolization, chemoembolization and systemic chemotherapy. Without treatment, the prognosis of hepatocellular carcinoma is poor, and mortality continues to be significant even in patients with small tumors detected during follow-up. For patients in Taiwan with advanced hepatocellular carcinoma, traditional herbal medicine is frequently used. However, neither the overall prevalence of this therapy nor its efficacy has been studied systematically. Spontaneous regression of cancer, although rare, may occur, but the mechanism leading to regression is still far from understood. Here, we report a case of hepatocellular carcinoma with complete regression after taking herbal medicine. We cannot be certain how significant the herbal preparation was in the regression of the hepatocellular carcinoma, but the regression of the tumor provides us a reason and hope for further research.

Fever therapy revisited

The phenomenon of spontaneous regression and remission from cancer has been observed by many physicians and was described in hundreds of publications. However, suggestive clues on cause or trigger are sparse and not substantiated by much experimental evidence. In this review, literature is surveyed and summarised and possible causes are discussed. At least in a larger fraction of cases a hefty feverish infection is linked with spontaneous regression in time and is investigated as putative trigger. Epidemiological and immunological evidence is put into perspective. An online forum to discuss the possible application of fever therapy in the future can be accessed at http://bioinfo.tg.fh-giessen.d e/fever-and-cancer.

Spontaneous regression of a large hepatocellular carcinoma with skull metastasis

Spontaneous regression of hepatocellular carcinoma (HCC) is a rare phenomenon. This case of a 65-year-old Korean man with HCC and metastatic frontal bone mass that regressed after radiotherapy for frontal bone mass without any other therapeutic modalities is described. The clinical diagnosis of HCC was made because of the presence of a liver mass on abdominal computed tomography (CT) scan, high serum alpha-fetoprotein value and tissue diagnosis on frontal bone biopsy. The patient refused any other recommended treatments, but accepted the radiation therapy due to a painful frontal bone mass, and ingested mushroom called Phellinus linteus for one and a half years. Ten months after radiation therapy, he experienced a reduction in size of the frontal bone mass and improvement of lesions in the liver, sternum and ribs. The patient is alive and in good condition without any symptoms or tumor aggravation in August 2002. It was concluded that a rare case of spontaneous regression of HCC had occurred.

Complete spontaneous remission of non-small-cell lung cancer: a case report

Spontaneous remission (SR) of cancer is a rare event, particularly in lung cancer. We report the case of a 68-year-old man, who came to our attention with a diagnosis of poorly differentiated pulmonary adenocarcinoma and, in absence of any active therapy, underwent a durable complete SR. Our case supports the rare occurrence of SR in non-small-cell lung cancer (NSCLC).

Recurrence of hepatocellular carcinoma with rapid growth after spontaneous regression

We report an 80-year-old man who presented with sponta- neous regression of hepatocellular carcinoma (HCC). He complained of sudden right flank pain and low-grade fever. The level of protein induced by vitamin K antagonist (PIVKA)-II was 1137 mAU/mL. A computed tomography scan in November 2000 demonstrated a low-density mass located in liver S4 with marginal enhancement and a cystic mass of 68 mm × 55 mm in liver S6, with slightly high density content and without marginal enhancement. Angiography revealed that the tumor in S4 with a size of 25 mm × 20 mm was a typical hypervascular HCC, and transarterial chemoembolization was performed. However, the tumor in S6 was hypovascular and atypical of HCC, and thus no therapy was given. In December 2000, the cystic mass regressed spontaneously to 57 mm × 44 mm, and aspiration cytology revealed bloody fluid, and the mass was diagnosed cytologically as class I. The tumor in S4 was treated successfully with a 5 mm margin of safety around it. The PIVKA-II level normalized in February 2001. In July 2001, the tumor regressed further but presented with an enhanced area at the posterior margin. In November 2001, the enhanced area extended, and a biopsy revealed well-differentiated HCC, although the previous tumor in S4 disappeared. Angiography demonstrated two tumor stains, one was in S6, which was previously hypovascular, and the other was in S8. Subsequently, the PIVKA-II level started to rise with the doubling time of 2-3 wk, and the tumor grew rapidly despite repeated transarterial embolization with gel foam. In February 2003, the patient died of bleeding into the peritoneal cavity from the tumor that occupied almost the entire right lobe. Considering the acute onset of the symptoms, we speculate that local ischemia possibly due to rapid tumor growth, resulted in intratumoral bleeding and/or hemorrhagic necrosis, and finally spontaneous regression of the initial tumor in S6.

The role of the immune system in the control of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is common, and current therapies may not be suitable for the majority of patients with advanced disease. Cases of spontaneous regression suggest that immune mechanisms are important in the control of HCC. Experiments in animal models have shown that tolerance to HCC associated antigens can be overcome and using a number of different techniques researchers have been able to prevent the growth of implanted tumours. The most promising of these techniques is based on the use of dendritic cells, which are able to process and present antigens to activate naive T cells and, when loaded with tumour antigens, can stimulate a specific and durable anti-tumour response. The success of animal studies has led to interest in the clinical applicability of HCC immunotherapy. Non-specific adoptive immunotherapy has been successful in preventing disease recurrence after resection and cellular vaccines based on dendritic cells are now entering clinical trials. The use of dendritic-cell vaccination raises exciting possibilities of preventing the formation of HCC in high-risk individuals such as those with cirrhosis.

Spontaneous regression in small cell esophageal carcinoma

Spontaneous regression or remission of cancers has been defined as the disappearance of the malignancies without any treatment or with obviously inadequate treatment. Spontaneous regression is rare, while any case with a small cell carcinoma in the esophagus was not found in the literature. We experienced a 73-year-old man with small-cell carcinoma in the thoracic esophagus whom underwent esophagectomy with lymphadenectomy. A pathological examination of the resected specimens found metastasis from the small cell carcinoma in the mediastinal lymph nodes, but no malignant cells in the esophageal lesion--an ulcer scar from which the biopsy specimen was taken to be a small-cell carcinoma. This may be the first case report that spontaneous regression in a small-cell carcinoma in the esophagus was found by esophagectomy and pathological examination.

Spontaneous regression of advanced cancer: identification of a unique genetically determined, age-dependent trait in mice

We have established and studied a colony of mice with a unique trait of host resistance to both ascites and solid cancers induced by transplantable cells. One dramatic manifestation of this trait is age-dependent spontaneous regression of advanced cancers. This powerful resistance segregates as a single-locus dominant trait, is independent of tumor burden, and is effective against cell lines from multiple types of cancer. During spontaneous regression or immediately after exposure, cancer cells provoke a massive infiltration of host leukocytes, which form aggregates and rosettes with tumor cells. The cytolytic destruction of cancer cells by innate leukocytes is rapid and specific without apparent damage to normal cells. The mice are healthy and cancer-free and have a normal life span. These observations suggest a previously unrecognized mechanism of immune surveillance, which may have potential for therapy or prevention of cancer.

Antitumor activity of Virulizin, a novel biological response modifier (BRM) in a panel of human pancreatic cancer and melanoma xenografts

PURPOSE

To define the anticancer efficacy of Virulizin in vivo as a single agent or in combination with conventional drugs in human pancreatic tumor and melanoma xenografts.

METHODS

The therapeutic effect of Virulizin was evaluated in a series of human tumor xenografts in athymic nude mice.

RESULTS

Virulizin had a high level of antitumor activity against all the pancreatic tumors (BxPC-3, SU 86.86. and Mia-PaCa-2) and melanomas (C8161 and A2058), as indicated by suppression of tumor growth with an optimal T/C value of <or=40% when administered as a single agent. No significant changes in Virulizin antitumor activity were observed when different schedules (3 days/week vs 7 days/week) or routes of administration (i.p. vs i.m.) were used. In combination therapy, Virulizin significantly enhanced the antitumor activity of gemcitabine and 5-fluorouracil against pancreatic tumors and of dacarbazine against metastatic melanomas, as reflected by a further decrease in tumor growth as compared to tumors in animals treated with the conventional drugs alone.

CONCLUSION

These studies suggest that Virulizin effectively inhibits the growth of solid human pancreatic tumors and melanomas in the xenograft model.

Increased apoptosis in infiltrating mononuclear cells of colorectal cancer: a mechanism for tumor escape

CONTEXT

Disturbance in apoptosis has been proposed as one of the mechanisms involved in the immune response targeting tumor outgrowth. How colorectal cancer cells escape from attack by the immune system is not yet fully understood.

OBJECTIVE

To investigate apoptotic molecules associated with colorectal cancer counterattack.

DESIGN AND SETTING

Tissue samples of colon from 12 patients with colorectal cancer were collected and analyzed by immunostaining. In addition to tumorous tissues, corresponding nontumorous specimens of colon were obtained as controls.

MAIN OUTCOME MEASURES

We examined the expression of Bcl-2, Bcl-xl, Bax, caspase-3, and inducible nitric oxide synthase in infiltrating mononuclear cells of colorectal cancer tissues and also in colorectal cancer tissues. The TUNEL assay was used to detect in situ apoptosis.

RESULTS

Apoptosis was barely detectable in specimens of colorectal cancer, which was consistent with an increase in Bcl-2 level and a decrease in caspase-3 level. In contrast, infiltrating mononuclear cells of tumorous tissues showed a marked increase in apoptosis compared with those of nontumorous tissues. The increased apoptosis might have resulted from an imbalance of antiapoptotic and proapoptotic molecules, as reflected by reduction of Bcl-2 level and elevation of Bax level. The elevated caspase-3 levels found in this study could be a downstream effector of the Bcl-2 and Bax apoptotic pathways. A significant increase in inducible nitric oxide synthase observed in the infiltrating mononuclear cells might contribute to immunosuppression seen in colorectal cancer.

CONCLUSION

It is tempting to speculate that aberrant expression of apoptotic molecules and inducible nitric oxide synthase in infiltrating mononuclear cells provides the underlying mechanism through which colorectal cancer cells escape attack by the immune system and subsequently grow without control.

Spontaneous regression of neoplasms: new possibilities for immunotherapy

In mammalian cells, neoplastic transformation is directly associated with the expression of oncogenes, loss or simple inactivation of the function of tumour suppressor genes and the production of certain growth factors. Genes for suppression of the development of the neoplastic cellular immunophenotype, as well as inhibitory growth factors, have regulatory functions within the normal processes of cell division and differentiation. Telomerase (a ribonucleoprotein polymerase) activation is frequently detected in various neoplasms. Telomerase activation is regarded as essential for cell immortalisation and its inhibition may result in spontaneous regression of neoplasms. This phenomenon of neoplasms occurs when the malignant tissue mass partially or completely disappears without any treatment or as a result of a therapy considered inadequate to influence systemic neoplastic growth. This definition makes it clear that the term 'spontaneous regression' applies to neoplasms in which the overall malignant disease is not necessarily cured and to cases where the regression may not be complete or permanent. A number of possible mechanisms of spontaneous regression are reviewed, with the understanding that no single mechanism can completely account for this phenomenon. The application of the newest immunological, molecular biological and genetic insights for more individualised and adequate antineoplastic immunotherapy (alternative biotherapy) is also discussed.

Spontaneous regression of stage IV clear cell carcinoma of the endometrium in a patient with essential thrombocytosis

OBJECTIVE

The aim of this study was to document a case of advanced stage clear cell carcinoma of the endometrium which underwent spontaneous regression (SR) and comment on the possible contribution of the patient's thrombocytosis.

CASE REPORT

A 73-year-old woman with essential thrombocytosis presented with vaginal bleeding. Imaging demonstrated a complex uterine mass, a 4-cm infrarenal mass, and a 5-cm subumbilical mass. Biopsy of the subumbilical mass revealed adenocarcinoma, and endometrial curettage revealed extensively necrotic clear cell endometrial carcinoma. At hysterectomy 5 weeks later, the infrarenal and subumbilical masses were not identified. The endometrial tumor was almost completely necrotic. She received no adjuvant therapy and remains disease-free 6 years later. Interestingly, her platelet-lowering agent (hydroxyurea) was discontinued shortly before, and her platelet count was significantly elevated at the time of her presentation with endometrial carcinoma.

CONCLUSION

This report documents a rare case of SR of advanced endometrial carcinoma, and we speculate that increased circulating platelets were a major contributing factor.

Spontaneous regression of a germinoma in the pineal body after placement of a ventriculoperitoneal shunt

The authors report a case in which a germinoma in the pineal body displayed spontaneous regression after placement of a ventriculoperitoneal (VP) shunt. Spontaneous regression of malignant tumors is extremely rare, occurring in only one of 60,000 to 100,000 patients. Although in rare cases spontaneous regression is known to occur in patients with testicular seminomas, only one case of spontaneous regression of a primary pineal germinoma has so far been reported. In the present case a 17-year-old man presented with headache. A tumor in the pineal body and acute hydrocephalus were revealed by head computerized tomography (CT) and magnetic resonance (MR) imaging, and VP shunt placement was performed. Computerized tomography scanning of the head was performed four times during a 2-week period following the operation, and the patient was temporarily discharged to return to school. At the time of discharge, CT scanning demonstrated no change in the size of the tumor. Two months later, the patient was readmitted to the hospital to undergo surgery. At that time, head MR imaging revealed regression of the tumor. The pathological diagnosis of the lesion was germinoma. The patient underwent three courses of chemotherapy, during which carboplatin and etoposide were administered, in addition to a 24-Gy dose of radiotherapy. No manifestations of nerve impairment were noticed, and the patient was observed on an outpatient basis. The authors think that the factors involved in tumor regression included the effects of the VP shunt, the effects of radiation absorbed during head CT scanning, and the role of the patient's own immune response. However, no conclusion has been reached concerning the actual cause.

Spontaneous regression of hepatocellular carcinoma and review of literature

A 68-year-old man presented with multiple hepatocellular carcinoma, which was considered to be unresectable at the first admission in January 1994. Pathological diagnosis was made by biopsy of the one lesion among them. From January 1994 to December 1997, 10 transarterial chemoembolizations and six percutaneous ethanol injection therapies were performed on the tumours in the cirrhotic liver. In February 1998 the tumour situated in the right lobe began to increase in size. The maximum tumour diameter was 6.3 cm measured by computed tomography (CT). In the beginning of May 1998 moderate ascites was present and mild hepatic encephalopathy was noticed. The patient was in the terminal stage of hepatocellular carcinoma and no further treatment was possible at that time. However, serum alpha-fetoprotein and protein induced by vitamin K absence or antagonist II dramatically decreased in June 1998. The CT scan also showed that the tumour had completely regressed without specific treatment. In February 1999 a new biopsy-proven hepatocellular carcinoma, 2 cm in diameter, developed in the lateral segment of the liver. It was well treated by percutaneous ethanol injection therapy. The patient was alive in good condition without any symptoms or tumour recurrence in June 1999. It was concluded that a rare case of spontaneous regression of hepatocellular carcinoma had occurred.

Spontaneous regression of hepatocellular carcinoma--a case report

Spontaneous regression of cancer is a rare phenomenon seldom described in patients with hepatocellular carcinoma. A 54-year-old Korean woman suffered from cytologically-proved advanced hepatocellular carcinoma, for which she received no treatment. Papanicolaou's smears revealed high cellularity. Many clusters of polygonal cells showed long, thick anastomosing cords covered by flattened endothelial cells. The polygonal cells showed small hepatocytoid appearance, characterized by increased nuclear/cytoplasmic ratio. She remained in good clinical condition and, at 4 years of follow-up, the hepatocellular carcinoma could not be visualized radiologically. To date, only 14 case reports of apparently spontaneous regression of hepatocellular carcinoma have been published in the English literature. The mechanisms underlying this intriguing phenomenon remain unknown.

Immunomodulation therapy in colorectal carcinoma

There has been much progress in the understanding of the relationship between the immune system and colorectal cancer. This has led to the use of immunomodulatory therapy in the adjuvant and palliative treatment of the condition. Although attempts at the use of non-specific immunomodulation with agents such as levamisole, cimetidine, alpha interferon and Bacillus Calmette-Guerin (BCG) have not produced significant clinical benefits when tested in randomized trials in both the adjuvant setting and for metastatic disease, promising results are being obtained with more specific therapy. Edrecolomab [corrected], a murine monoclonal antibody targeting the 17-1A antigen on malignant colorectal cells has produced a reduction in relapse and mortality rates when used as adjuvant treatment following surgery for Dukes' C colon cancer. Active specific therapy with autologous tumour vaccine administered with BCG has produced similar benefits in Dukes' B cancer. Both 3H1 anti-idiotypic antibody against carcinoembryonic antigen and 105AD7 antibody to gp72 glycoprotein have demonstrated in-vitro and in-vivo immune activation against tumour. Non-randomized studies postulate prolongation of survival using these antibodies in advanced disease. These agents are all currently being tested in randomized studies powered to detect meaningful survival differences and clinical benefit. Immune therapy offers the potential of low toxicity therapy in colorectal cancer and may have a role as an adjunct to conventional chemotherapy.

[Not Available]

Oncologists have been reluctant a long time to accept the existence of spontaneous remissions in cancer disease. The considerable number of patients whose cancer-disease has regressed without (adequate) treatment should have allayed these doubts. Such remissions could serve as a kind of natural experiments that may lead to greater insights in the biology of tumours and to more efficient therapeutic strategies. In the moment the discussion deals with the explanation of spontaneous remissions by the existing biological or psychosomatic theories. Whereas the fact of spontaneous remissions was denied on the one hand some people claim the occurrence of such remissions for themselves without justification. In order to obtain an epidemiological register of these cases it would be necessary to document all patients in question in a standardised manner. Such a set of data should include psychosocial variable as well since the psychosomatic approach seems to be even more in danger of speculations that resemble closely the causal attributions of the patients.

Natural adjuvants: endogenous activators of dendritic cells

Dendritic cells, the most potent antigen-presenting cells, need to be activated before they can function to initiate an immune response. We report here that, in the absence of any foreign substances, dendritic cells can be activated by endogenous signals received from cells that are stressed, virally infected or killed necrotically, but not by healthy cells or those dying apoptotically. Injected in vivo with an antigen, the endogenous activating substances can function as natural adjuvants to stimulate a primary immune response, and they may represent the natural initiators of transplant rejection, spontaneous tumor rejection, and some forms of autoimmunity.

Hepatocellular carcinoma with spontaneous regression of multiple lung metastases

Spontaneously regressed lung metastasis of hepatocellular carcinoma (HCC) in a 82-year-old Japanese man with liver cirrhosis was recorded. Multiple nodular lesions of both lungs, up to 1 cm across, were shown on chest X-ray when the clinical diagnosis of HCC was made because of the presence of a liver mass on abdominal computed tomography (CT) scan and high serum alpha-fetoprotein (AFP) value. The lung lesions which were regarded clinically as metastasis of HCC decreased in number and size 7 months later, and subsequently disappeared a further 7 months radiographically. However, the liver mass revealed no reduction on abdominal CT, despite normalization of the serum AFP value, and the patient died 7 months after the disappearance of the lung lesions. The patient refused biopsy for the liver mass and anticancerous treatment during the course of the disease. At autopsy, the liver mass, 13 cm in diameter, histologically featured moderately differentiated HCC. Only one metastasis, 0.5 cm across, was obvious in the left lower lung lobe. In addition, there were 14 minute lesions in both lungs, up to 0.2 cm across, including three with complete necrosis and 11 with histocytic reaction and fibrosis. The necrotic tissue was filled with large ghostly cells that appeared to be debris from a neoplastic tissue, regardless of no viable tumor cells among them. The clinical and autopsy findings highly suggested that the patient developed spontaneous regression of multiple lung metastases of HCC and subsequently left the very small lesions as the vestige. Thus, the histology of these lesions may exhibit a process of the regression as the sequence of events, i.e., a transition from necrosis of the metastatic HCC to its fibrosis. Presence of an effective factor(s) in relation to the regression was unclarified. There has been no reported cases with regression of the only metastasis of HCC in the literature to date.

Spontaneous regression of pulmonary metastases demonstrated by CT

Two cases of disappearing or spontaneous regression of pulmonary metastases on CT are presented. In both cases, cytological proof was obtained by radiologically guided fine needle aspiration. The lesions subsequently regressed on follow-up CT studies without recognized systemic treatment.

Merkel cell carcinoma with partial spontaneous regression: an immunohistochemical, ultrastructural, and TUNEL labeling study

We report a case of Merkel cell carcinoma that partially regressed after biopsy. A 76-year-old woman presented with an 1 month history of a rapidly enlarging nodule on her left cheek. After biopsy, the nodule reduced to almost half the size and was excised 1 month later. The excised specimen showed a dense cluster of lymphocytes and fibrosis around the tumor nests. In addition, lymphocytes showed apposition with tumor cells. An immunohistologically dense, even infiltration of CD4+ and CD8+ cells was found around the tumor nests, and more CD8+ cells than CD4+ cells were seen in the tumor nests. By electron microscopy (EM), apoptosis of tumor cells and lymphocytes was observed. Many apoptotic cells were also detected by in situ nick end-labeling (TUNEL) of DNA-breaks, especially in the marginal area of tumor nests surrounded by dense lymphocytic infiltrates. It seems likely that T-cell immunity, which induces apoptosis of tumor cells, may have been involved in tumor regression.

Complete spontaneous remission in a patient with metastatic non-small-cell lung cancer. Case report, review of the literature, and discussion of possible biological pathways involved

Spontaneous remission of cancer (SR) is defined as a complete or partial, temporary or permanent disappearance of all or at least some relevant parameters of a soundly diagnosed malignant disease without any medical treatment or with treatment that is considered inadequate to produce the resulting regression. We report the case of a 61-year-old man who presented with extensive metatastic disease five months after pneumonectomy for poorly differentiated large cell and polymorphic lung cancer. A vast metastatic tumour mass of the abdominal wall was confirmed histolologically and there was clinical and radiographic evidence of liver and lung metastases. Eight months later, the patient was operated on for a hernia, which had developed in the inguinal biopsy scar and the surgeon confirmed complete clinical SR of the abdominal wall metastases. Again five months later there was no longer any radiologic evidence of liver and lung metastases. Complete remission has persisted more than five years. Histology of the primary and of the abdominal metastases were reviewed by several independent pathologists. SR is an extremly rare event in lung cancer. This is the first documented case of clinically evident visceral metastases of a bronchiogenic adenocarcinoma developing after complete resection of the primary and then showing complete SR. The epidemiology of SR is reviewed and possible mechanisms involved in SR are discussed.