Immunity to malignant disease in man

A Century of Radiation Therapy and Adaptive Immunity

The coming of age for immunotherapy (IT) as a genuine treatment option for cancer patients through the development of new and effective agents, in particular immune checkpoint inhibitors, has led to a huge renaissance of an old idea, namely to harness the power of the immune system to that of radiation therapy (RT). It is not an overstatement to say that the combination of RT with IT has provided a new conceptual platform that has re-energized the field of radiation oncology as a whole. One only has to look at the immense rise in sessions at professional conferences and in grant applications dealing with this topic to see its emergence as a force, while the number of published reviews on the topic is staggering. At the time of writing, over 97 clinical trials have been registered using checkpoint inhibitors with RT to treat almost 7,000 patients, driven in part by strong competition between pharmaceutical products eager to find their market niche. Yet, for the most part, this enthusiasm is based on relatively limited recent data, and on the clinical success of immune checkpoint inhibitors as single agents. A few preclinical studies on RT-IT combinations have added real value to our understanding of these complex interactions, but many assumptions remain. It seems therefore appropriate to go back in time and pull together what actually has been a long history of investigations into radiation and the immune system (Figure 1) in an effort to provide context for this interesting combination of cancer therapies.

Magnesium (and trace substance) deficiencies in the pathogenesis of cancer

Except for a few experimental models of magnesium (Mg)-deficiency-induced neoplasms, less attention has been paid in the past quarter century in the Western world to this macromineral than to the trace elements; e.g., selenium (Se) and zinc (Zn), and to vitamins, deficiencies of which are each considered probable factors in oncogenesis. Although early epidemiologic studies showed an inverse correlation between the amount of Mg in soil and water and the incidence of (gastric) cancer, and several animal studies supported the premise that Mg has a prophylactic effect against induction of cancer, other studies showed that Mg supplementation increased the growth of established experimental tumors. Thus, enthusiasm for this approach subsided. The early epidemiologic findings have since been confirmed, and there have been studies demonstrating the importance of Mg in maintaining immunocompetence, and others indicating that immunodeficiencies increase susceptibility to the development of cancer. Evidence has now accrued that indicates that Mg deficiency increases susceptibility to chemical oncogens. The abnormal metabolism of tryptophan (yielding a carcinogenic metabolite) that indicates functional or absolute pyridoxine deficiency is an indirect clue to Mg deficiency. Vitamin B6-activated enzymes require Mg as a cofactor. However, the early warnings against the use of Mg as part of an antineoplastic program against established cancer were justified, since rapidly metabolizing cells (such as cancers) are dependent on Mg.There are similarities between experiences with Mg and with Se and Zn. All three are required for normal metabolism; Se also protects against free radicals in the environment. Mg and Zn have increased established tumor growth, and their depletion has been applied to antineoplastic programs, with risks comparable to those of using antimetabolic agents.

Lymphocytic infiltrates in primary glioblastomas and recidivous gliomas. Incidence, fate, and relevance to prognosis in 228 operated cases

The correlation existing in several human malignancies between lymphocytic infiltration and prolonged survival prompted this study. Two hundred selected patients who were operated on for glioblastoma were reviewed to investigate the incidence of the lymphocytic infiltration in the histological slides and its possible relevance to a better clinical course. The group that exhibited a definite lymphocytic infiltration (Group A, 11.5%) had a significantly longer preoperative history and postoperative survival (p less than 0.01) than the other two groups that presented slight or no infiltration (Group B, 23%, and Group C, 65%, respectively). In addition, biopsies of 28 recidivous gliomas were reviewed to study the fate of this lymphocytic infiltration in relation to time and therapy, such as irradiation and steroids which are known to depress the immune response. The authors found that severe lymphocytic infiltration is a rare immunobiological reaction which significantly improves the prognosis of a malignant brain tumor and seems not to be influenced by time, local x-ray therapy, or steroids.

Does cyclophosphamide induce bladder cancer?

An increasing incidence of bladder neoplasms temporally associated with chemotherapy, usually cyclophosphamide, is being reported. These secondary primary bladder malignancies are characteristically found in two groups of patients: those with lymphoproliferative or myeloproliferative tumors, and those with immunosuppression after organ transplantation. A case of adenocarcinoma of the bladder associated with malignant lymphoma is reported, and the known cases of second primary bladder malignancies after cyclophosphamide therapy as reported in the literature are reviewed. Studies relating to the enhanced occurrence of second primary cancers in lymphoproliferative disorders are presented. The recognized urologic toxicities of cyclophosphamide, including cytopathologic changes in animals and humans, are discussed. The observed association between immunosuppression and second primary malignancies is explored, as supported by studies on congenital immunodeficiency in humans, viral oncogenesis in experimental animals, and neoplasia after organ transplantation. Possible mechanisms of carcinogenesis associated with cyclophosphamide are reviewed, including suppression of humoral and cell-mediated immune defense mechanisms, direct carcinogenesis, or cocarcinogenesis. A plea is made for the orderly reporting and careful documentation of bladder tumors in patients receiving cyclophosphamide. It is suggested that prospective studies in these patients and in patients receiving cyclophosphamide for nonmalignant disorders would be of value in assessing the culpability of cyclophosphamide as a carcinogen.

Lymphocytic infiltration in long-survival glioblastomas: possible host's resistance

A series of 200 patients operated on at the Rome University Neurosurgical Clinic for primary glioblastoma is analyzed. Eight of these patients (4%) survived for over four years. The histological preparations showed more or less heavy perivascular lymphocytic infiltration in six of these cases. Since such infiltrations in malignant tumours of other organs are recognized as having an immune function, expressing the host's resistance to his tumour, the longer survival of the cases considered may well denote an immune defensive mechanism.

Malignant melanoma of the head and neck in children. Review of the literature and report of a case

Perusal of the literature revealed that until 1970, 13 children with malignant melanoma of the head and neck had been reported. This group includes two cases of melanoma that developed in a giant cell nevus, as well as one case of congenital melanoma. The biologic features of prepubertal melanoma appear basically analogous to those of the adult variety. Malignant melanoma of the auricle is described in a 2 1/2-year-old child. Surgical therapy was given, and BCG vaccination was used as an adjuvant. The patient is alive and free of signs of the disease 2 1/2 years following the operation. This appears to be the third reported case of malignant melanoma of the external ear in a child.

Immunocompetence and spontaneous regression of metastatic renal cell carcinoma

Spontaneous remission of pulmonary metastases from renal cell carcinoma was correlated with a positive response to dinitrochlorobenzene (DNCB). When first seen, the patient was DNCB negative and a chest radiograph showed nodular densities in the right lung and left midlung. Six months after sensitization, the patient had a positive response to DNCB and no evidence of lung metastases. Three mo later, the patient developed brain metastases although X-ray examination showed no pulmonary nodules. A diminished response to DNCB noted over the next several months and chest X ray verified the return of pulmonary metastases.

Tumour immunology and the gut

This review set out to answer several questions related to tumour immunology and the gut. It is evident that in patients with gastrointestinal cancer there is a general depression of the immune response and this seems to be correlated with the stage of the disease. Paradoxically a specific immune response against definable tumour antigens can be demonstrated, both cellular and humoral mechanisms being involved although the complexities of this paradox require further analysis. Immunotherapy has been employed in gastrointestinal tumours in a sporadic way. The results suggest that gastrointestinal neoplasms may respond at least as well as other tumours. A firm conclusion awaits the results of controlled trials in which the bulk of the tumour has been effectively dealt with by other means or where combined immunochemotherapy is being used.

Immunotherapy of malignant disease in man

At present active specific immunotherapy should only be attempted where a tumour is shown to be antigenic and immunogenic, patients are immunocompetent, large numbers of tumour cells can be stored and minimal residual disease can be achieved without heavy immunosuppression. Acute myeloblastic leukaema (AML) satisfies such criteria reasonable well and evidence is presented that treatment with BCG and irradiated allogeneic AML cells is of value in this disease. It is suggested that there is insufficient evidence at present to justify embarking on similar regimes in most of the malignant lymphomas.

The role of circulating antibody in the control of metastases

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Depression of immune responsiveness in breast and large-bowel tumours as measured by heterophile antibody activity

Decrease in heterophile antibody activity to cow, pig, and sheep red blood-cells was found in groups of patients with large-bowel and breast tumours irrespective of the extent and spread of the tumour or the length of known history. The significance of these observations is discussed in the light of known cancer-surveillance mechanisms. The findings may reflect decreased host immunological resistance to these tumours even in the early stage of their development, and the measurement of heterophile antibody activity may provide a useful and uncomplicated screening test.

Glioblastoma multiforme: a controlled trial to assess the value of specific active immunotherapy in patients treated by radical surgery and radiotherapy

The results are reported of a randomized prospective clinical trial carried out to assess the value of specific active immunotherapy using irradiated autologous tumour cells in patients with glioblastoma multiforme treated by radical surgery and post-operative irradiation. The results in 62 patients show no statistically significant difference in survival between the group receiving adjuvant autologous tumour cells and those treated with surgery and radiotherapy alone. All 27 patients receiving tumour cells were dead at 30 months, whereas 7 of the 35 controls were alive at this time. The results were considered sufficiently discouraging to abandon the trial at this stage on the grounds that there was sufficient evidence in this study that the administration of irradiated autologous cells was of no benefit to patients with high grade astrocytomata.

The significance of lymphocytic infiltration in neuroblastoma

A study of the significance of lymphocytic infiltration was made in a retrospective series of 23 primary neuroblastomata. The degree of lymphocytic infiltration was estimated and scored in 5 categories. Non-parametric rank order statistical methods were used to establish quantitative correlations, particularly with the duration of survival. A significant positive correlation was found both in infancy and childhood. It was found, unexpectedly, that the presence of metastases did not invalidate the correlation between lymphocyte score and survival.

Transience of immune responses to tumour antigens in man

By examining serial serum samples from patients undergoing surgical removal of malignant tumours an increased incidence of tumour-specific antibodies has been detected. Antibody responses to tumour neoantigens seem to be transient, and this is held to account for the rarity of detections where a single sample of serum is examined.

Oestrogen as a reticuloendothelial stimulant in patients with cancer

Stimulation of reticuloendothelial activity may benefit patients with cancer. Oestrogenic compounds are known to stimulate reticuloendothelial phagocytic activity in animals and a similar effect is demonstrated in patients.The depression of reticuloendothelial phagocytic activity which follows radiotheraphy in the treatment of cancer can be prevented by the simultaneous administration of stilboestrol. Possibly this could be associated with a more favourable response to therapy, and a controlled trial is needed to establish this.

Immunological factors in cysts of the jaws

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Host resistance and survival in carcinoma of breast: a study of 104 cases of medullary carcinoma in a series of 1,411 cases of breast cancer followed for 20 years

This paper deals with a special type of mammary carcinoma, generally of high-grade malignancy, which carries a remarkably good prognosis-the so-called "medullary carcinoma of the breast with lymphoid infiltrate." Probably the increased lymphoid tissue seen in these tumours is concerned with cell-mediated and humoral immunological reactions and reflects a strong host-defence mechanism which is responsible for the remarkably high survival rates following radical treatment. Since the evidence for host resistance to malignant disease is based largely on animal data, the opportunity to study a group of patients followed for 20 years, in whom this type of defence reaction appears to exist, is of considerable clinical interest.Among 1,411 cases of breast cancer there were 104 with medullary carcinoma (7.4%), for which the corrected 5- to 20-year survival rates have been calculated. After 20 years 74% of cases with operable medullary tumours were alive, compared with 14% of cases with similar stage non-medullary cancer. In the presence of histologically proved axillary metastases the 20-year survival rate was 61% for medullary cases, compared with only 13% for other types of breast cancer.In 30 cases of medullary cancer in which the axilla was free, the corrected 20-year survival rate was 95% following a combination of radical operation and radiotherapy. No evidence could be found that axillary dissection or postoperative irradiation is harmful to women with operable highly malignant breast cancer in whom a well-marked host resistance is thought to be present. A combination of radical mastectomy and postoperative irradiation appears to be the most effective treatment for such cases. The present grounds for rejecting a radical approach to treatment of breast cancer, based on current immunological considerations, are regarded as being quite inadequate.

Precancerous conditions of the oral mucosa. A computer-aided study

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