The concept that the immune system can recognize and destroy nascent transformed cells was originally embodied in the cancer immunosurveillance hypothesis of Burnet and Thomas. This hypothesis was abandoned shortly afterwards because of the absence of strong experimental evidence supporting the concept. New data, however, clearly show the existence of cancer immunosurveillance and also indicate that it may function as a component of a more general process of cancer immunoediting. This process is responsible for both eliminating tumors and sculpting the immunogenic phenotypes of tumors that eventually form in immunocompetent hosts. In this review, we will summarize the historical and experimental basis of cancer immunoediting and discuss its dual roles in promoting host protection against cancer and facilitating tumor escape from immune destruction.

Cancer immunoediting: from immunosurveillance to tumor escape.

Pathology and genetics of tumours of the urinary system and male genital organs

After a century of controversy, the notion that the immune system regulates cancer development is experiencing a new resurgence. An overwhelming amount of data from animal models--together with compelling data from human patients--indicate that a functional cancer immunosurveillance process indeed exists that acts as an extrinsic tumor suppressor. However, it has also become clear that the immune system can facilitate tumor progression, at least in part, by sculpting the immunogenic phenotype of tumors as they develop. The recognition that immunity plays a dual role in the complex interactions between tumors and the host prompted a refinement of the cancer immunosurveillance hypothesis into one termed "cancer immunoediting." In this review, we summarize the history of the cancer immunosurveillance controversy and discuss its resolution and evolution into the three Es of cancer immunoediting--elimination, equilibrium, and escape.

The three Es of cancer immunoediting.

Stress-induced immunological reactions to exercise have stimulated much research into stress immunology and neuroimmunology. It is suggested that exercise can be employed as a model of temporary immunosuppression that occurs after severe physical stress. The exercise-stress model can be easily manipulated experimentally and allows for the study of interactions between the nervous, the endocrine, and the immune systems. This review focuses on mechanisms underlying exercise-induced immune changes such as neuroendocrinological factors including catecholamines, growth hormone, cortisol, β-endorphin, and sex steroids. The contribution of a metabolic link between skeletal muscles and the lymphoid system is also reviewed. The mechanisms of exercise-associated muscle damage and the initiation of the inflammatory cytokine cascade are discussed. Given that exercise modulates the immune system in healthy individuals, considerations of the clinical ramifications of exercise in the prevention of diseases for which the...

Exercise and the Immune System: Regulation, Integration, and Adaptation

Skin cancers are the most common tumors in patients who have received organ transplants. This review discusses the epidemiology, pathogenesis, and management of squamous-cell and basal-cell carcinomas, cancers of the anogenital region, Kaposi's sarcoma, melanoma, neuroendocrine skin carcinoma, and cutaneous manifestations of lymphoma in transplant recipients.

Skin cancers after organ transplantation.

The theory that cancer may arise under conditions of reduced immune capacity is supported by observations of humans with immune deficiencies such as occur following organ transplants. However, no study on humans has been done in which the reference population was the same as that in which the cancer cases arose and in which there was a sufficiently long period of follow-up. Information on 5,692 Nordic recipients of renal transplants in 1964-1982 was linked with the national cancer registries (1964-1986) and population registries. Person-years at risk were calculated from the date of first transplantation until death or the end of the study period and were multiplied by the appropriate age- and calender-specific incidence rates to obtain the expected numbers of cancers. Standardized incidence ratios (SIR) were calculated after stratification by a number of recorded variables. Altogether, 32,392 person-years were accrued, and 471 cancers occurred, yielding overall SIR of 4.6 (95% CI, 4.0 to 5.2) for males and 4.5 (95% CI, 4.0 to 5.2) for females. Significant overall 2- to 5-fold excess risks in both sexes were seen for cancers of the colon, larynx, lung and bladder, and in men also for cancers of the prostate and testis. Notably high risks, 10-fold to 30-fold above expectation, were associated with cancers of the lip, skin (non-melanoma), kidney and endocrine glands, also with non-Hodgkin's lymphoma, and in women also with cancers of the cervix and vulva-vagina. Among a number of donor and recipient variables studied, including tissue types and compatibility (ABO, HLA, DR), age below 45 years at the time of transplantation was the most important determinant for increased risk at most sites. Kidney transplantation increases the risk of cancer in the short and in the long term, consistent with the theory that an impaired immune system allows carcinogenic factors to act. The tumor risk is small in comparison with the benefits of transplants, but patients should be followed up for signs of cancer.

Cancer risk after renal transplantation in the Nordic countries, 1964-1986.

Cadmium, mercury, and lead concentrations were determined in deep-frozen kidney cortex biopsies taken from 36 living, healthy Swedish kidney donors (18 males and 18 females), who were 30-71 (mean 53) years of age. Information about occupation, smoking, the presence of dental amalgam, and fish consumption could be obtained for 27 of the donors. The samples (median dry weight 0.74 mg) were analyzed using inductively coupled plasma mass spectrometry, and the results were transformed to wet-weight concentrations. The median kidney Cd was 17 micrograms/g (95% confidence interval, 14-23 micrograms/g), which was similar in males and females. In 10 active smokers, the median kidney Cd was 24 micrograms/g, and in 12 who never smoked, it was 17 micrograms/g. The median kidney Hg was 0.29 micrograms/g, with higher levels in females (median 0.54 micrograms/g) than in males (median 0.16 micrograms/g). Subjects with amalgam fillings had higher kidney Hg (median 0.47 micrograms/g, n = 20) than those without dental amalgam (median 0.15 micrograms;g/g, n = 6), but kidney Hg was below the detection limit in some samples. Nearly half of the samples had kidney Pb below the detection limit. The median kidney Pb was estimated as 0. 14 micrograms/g. This is the first study of heavy metals in kidney cortex of living, healthy subjects, and the results are relatively similar to those of a few previous autopsy studies, indicating that results from autopsy cases are not seriously biased in relation to kidney metal concentrations in the general population. Cd concentrations in those who never smoked were relatively high, indicating considerable Cd intake from the diet in Sweden. The effect of dental amalgam on kidney Hg was as expected, although the reason for the difference in Hg levels between males and females is unclear.

Cadmium, mercury, and lead in kidney cortex of the general Swedish population: a study of biopsies from living kidney donors.

Among 129 renal transplant patients with 3-16 years of posttransplant observation time, and residents in a low ultraviolet radiation area, 25 (19.4%) had premalignant or malignant skin lesions, a 3-fold increase over a control population collected randomly. Thirteen (10.1%) had skin cancer, a 7-fold increase. Nine patients had multiple lesions; none had metastatic disease. Multiple regression analysis revealed age, outdoor occupation, and transplantation/immunosuppression to be equally significant risk factors for skin malignancy. Transplant patients should be educated and periodically examined for early detection of skin malignancies.

Premalignant and malignant skin lesions in renal transplant patients.

The results of kidney transplantation in juvenile-onset diabetic patients were compared to those of an age-matched control group of non-diabetic patients, all of whom were transplanted with kidneys from living related donors during the period 1977-1982, and managed by the use of conventional immunosuppression. The 5-year actuarial patient and graft survival rates did not differ significantly between the groups: 79% and 68% in diabetic patients and 88% and 72% in non-diabetic patients, respectively. The graft function was stable in both diabetic and non-diabetic patients. Early surgical complications in both groups were few. Peripheral vascular insufficiency leading to amputation occurred only in diabetic patients, while hyperparathyroidism was recorded only in non-diabetic recipients. Primary cytomegalovirus infections were more common in diabetic patients. Providing good graft function was achieved, heart complications were a minor problem in both patient groups. However, cardiovascular complications were a leading cause of death in patients whose graft failed. The initial hospital stay was, on average, one week longer in diabetic patients, but the accumulated hospital stay in the three years following transplant was twice as long (1 month per year) in the diabetic group as in the non-diabetic. Rehabilitation during the last six months of follow-up was good in both groups and about 60% of diabetic and 90% of non-diabetic patients were working full- or part-time. Thus, the prospects for survival and rehabilitation were similar in diabetic and non-diabetic patients in the 5 years following transplant, but at a higher price in diabetes.

Morbidity and mortality in diabetic and non-diabetic recipients of living related donor kidneys.

Renal transplant biopsies were obtained from 16 patients with systemic lupus erythematosus 6 months to 11 years post-transplant. Eight biopsies were taken on clinical grounds while eight were elective. Histopathological findings suggesting recurrent lupus nephritis were found in seven biopsies, five of which were taken on clinical indication. By light-microscopy, five graft biopsies showed proliferative glomerulopathy and two glomerulosclerosis. Immunofluorescence was positive for IgM and C3 in a finely granular pattern in all biopsies, for C1q in three, but for IgG in only two. Electron-dense deposits were found in all seven biopsies with predominantly subendothelial location. All but one patient had clinical signs of renal involvement, but only three had extrarenal symptoms and three had serological signs of active SLE. Upon increased immunosuppressive therapy, renal and serological signs improved but one graft was later lost due to recurrent SLE nephritis.

I. Blohmé

Papers

Cancer risk after renal transplantation in the Nordic countries, 1964-1986.

Cadmium, mercury, and lead in kidney cortex of the general Swedish population: a study of biopsies from living kidney donors.

Premalignant and malignant skin lesions in renal transplant patients.

Morbidity and mortality in diabetic and non-diabetic recipients of living related donor kidneys.

Recurrence of SLE in transplanted kidneys: a follow-up transplant biopsy study