Occurrence of cancer in immune deficiencies

Post-transplantation malignancies: here today, gone tomorrow?

From the early days of transplantation onwards, increased cancer development in transplant recipients, who require immunosuppression to avoid graft rejection, has been recognized. Registry data indicate that approximately 10-30% of deaths are attributed to post-transplant malignancy, with an upward trend in this incidence as more patients have been exposed to chronic lifelong immunosuppression. In this Review, the overall incidence and most frequent types of cancer encountered are summarized, along with information about which transplant recipients are at the greatest risk of malignancy. Reasons for why differences exist in susceptibility to cancer in this patient population are examined, and approaches that might improve our understanding of the options available for reducing the incidence of this adverse effect of immunosuppression are described. Whether anti-rejection drugs have been successful in diminishing overall immunosuppressive burden, and consequently show any promise for decreasing post-transplant malignancies is also discussed. The topic shifts to one class of conventional anti-rejection drugs, the mammalian target of rapamycin (mTOR) inhibitors, which paradoxically have both immunosuppressive and anti-neoplastic properties. The complex activities of mTOR are reviewed in order to provide context for how these seemingly opposing effects are possible, and the latest clinical data on use of mTOR inhibitors in the clinic are discussed. The current and future perspectives on how best to normalize these unacceptably high rates of post-transplantation malignancies are highlighted.

Acute myeloid leukemia appearing in two patients after prolonged continuous chlorambucil treatment for Wegener's granulomatosis

Two patients with Wegener's granulomatosis have been treated with chlorambucil and prednisolone continuosly for 3 and 5 years, respectively. This treatment was effective in controlling the disease, but bone marrow toxicity with severe pancytopenia developed in both cases. Both patients died from thrombocytopenia with haemorrhagic pericarditis. In one case, the diagnosis of acute myeloid leukaemia was established from the appearance of myeloblasts in the peripheral blood and from characteristic bone marrow morphology. In the other case this diagnosis was strongly suspected on the basis of the bone marrow morphology alone. It is proposed that this development of acute leukaemia in two patients with a primary non-neoplastic disease may result from a direct carcinogenic action of chlorambucil in humans.

Prevalence of anal HPV infection in solid-organ transplant patients prior to immunosuppression

Patients that undergo organ transplantation have a high risk of developing various malignancies, depending on the duration and magnitude of immunosuppressive therapy. Among others, a 10-fold increased relative risk has been reported for the development of anal cancer. There is a strong association between persistent infection with high-risk mucosal types of human papillomavirus (HPV) and anogenital neoplasia. In this study we analysed the prevalence of anal HPV infection in organ transplant patients before starting immunosuppressive therapy. In a university transplant unit, patients ( n=60, 40 male, 20 female) that were undergoing solid-organ transplantation (kidney, liver) for the first time were routinely screened for anal HPV infection. Anal swabs were obtained within 24 h after transplantation and analysed for the presence of mucosal-type HPV DNA by liquid DNA/RNA hybridization [hybrid capture (HC) 2 test]. Overall, some type of HPV DNA was detected in 14/60 (23.3%) patients; 9/60 (15%) were positive for high-risk HPV and 8/60 (13.4%) were positive for low-risk HPV, and 3/60 (5%) were positive for both types. Prevalence of HPV infection tended to be higher in patients that were receiving liver transplants than in those receiving kidney transplants (29.4% vs. 20.9%), but the difference did not reach statistical significance. In our series of organ transplant patients the prevalence of previous HPV infection (23.3%) before immunosuppressive therapy was started was higher than that found in previous epidemiological studies or in a control group. In particular, there was a high rate (15%) of infection with oncogenic HPV types. These findings have important implications on screening and surveillance policies in this patient group at risk of developing neoplasias, including anal cancer.

Autoapheresis and intraoperative blood salvage in oncologic surgery

Transfusion of predeposit or salvaged autologous blood has continued to grow since the 1980s. Issues such as the indications for use and cost effectiveness as well as the safety of autologous blood salvaged during cancer surgery have emerged and should be addressed. The concern for possible contamination of autologous RBC with cancer cells responsible for metastasis has limited the use of autologous salvaged blood in cancer patients. Nevertheless, clinical experience has been gained on the use of salvaged blood in patients with colorectal, gastric, renal, hepatic, breast, bladder and lung cancer. No evidence has been reported showing an increase in metastasis or a decrease in patient survival, in spite of the obvious demonstration that salvaged blood is contaminated with viable tumor cells which are not washed out of the RBC layer during intraoperative blood salvage (IOBS). However, a number of limitations have hampered the widespread use of IOBS in these patients and the technique is not well established. Increasing knowledge of the deleterious effects of allogeneic blood transfusion both in terms of the increased number of viral or bacterial infections and the down-regulation of the patient's immune system have recalled attention to IOBS and to the techniques such as filtration, which might reduce the risk of reinfusion of cancer cells, or totally eliminate the risks such as irradiation has been proposed by Hansen's group. This paper reviews the topic with some emphasis on our personal experience with gamma and X-ray irradiation of salvaged blood in a large reference hospital, where IOBS and filtration of salvaged blood were established for use in cancer patients in 1993 and 1996.

Etiology and pathogenesis of AIDS-related non--Hodgkin's lymphoma

The incidence of NHL is greatly increased in HIV-infected individuals. The vast majority are clinically aggressive B cell-derived neoplasms exhibiting BL, IBL, or LCL histology. Approximately 80% arise systemically (nodal and/or extranodal), and the remaining 20% arise as primary CNS lymphomas. A small proportion are body cavity-based lymphomas associated with KSHV infection. Possible factors contributing to lymphoma development include HIV-induced immunosuppression, chronic antigenic stimulation, and cytokine overproduction. These alterations are associated with the development of oligoclonal B-cell expansions. The appearance of NHL is characterized by the presence of a monoclonal B-cell population displaying a variety of genetic lesions, including EBV infection, c-myc gene rearrangement, bcl-6 gene rearrangement, ras gene mutations, and p53 mutations/deletions. The number and type of genetic lesions varies according to the anatomic site and histopathology. In the case of BL, virtually 100% exhibit c-myc gene rearrangements, two thirds display p53 gene mutations, one third contain EBV, and none exhibit bcl-6 gene rearrangements. In contrast, in the case of IBL, virtually 100% contain EBV, 25% display c-myc gene rearrangements, 20% display bcl-6 gene rearrangements, and very few exhibit p53 gene mutations. These findings suggest that more than one pathogenetic mechanism is operational in the development and progression of AIDS-related NHLs. Further work will be necessary to develop a complete understanding of the etiology and pathogenesis of NHL in the setting of HIV infection. AIDS-related NHL remains an important biologic model for investigating the development and progression of high-grade NHLs as well as NHLs that develop in immune-deficient hosts.

[Transfusion and cancer]

Relationship between blood transfusion and cancer is considered from five points of view: 1) The cancer patient as a blood donor. Cancer must remain a cause of exclusion from blood donation. 2) Autologous blood transfusion for cancer patients. Predeposited autologous blood transfusion is only possible for a small number of patients. Intraoperative blood salvage carries with it the risk of disseminating tumor cells. 3) History of blood transfusion and the risk of having a cancer: a) the persistence of immune alterations following blood transfusion for years might expose the patient to an increased risk of having a cancer; b) blood transfusion might carry immunosuppressive viruses, and hepatitis viruses are related to the risk of liver cancer. 4) Cancer recurrence and blood transfusion. Conclusion of most of the published studies is that blood transfusion is associated with an increased risk of recurrence of colorectal cancer. The only realistic randomized study would compare different transfusion strategies (allogenic, leukocyte poor allogenic and autologous blood transfusion) to determine which is the best for cancer patients. 5) Post-transfusion GVH in cancer patients. Some cases have recently been published. They all can be explained by a particular HLA compatibility between the recipient and one of the blood donors.

Brainstem glioma after radiation therapy for acute myeloblastic leukemia in a child with Down syndrome. Possible pathogenetic mechanisms

A 13-year-old boy with Down syndrome (DS) had a brainstem glioma confirmed at autopsy, 10 years after receiving prophylactic cranial irradiation for acute myeloblastic leukemia. There is no clear association of brain tumors with DS; despite a reported link between leukemia and glioma, a causal association with radiation therapy is more likely.

Methotrexate therapy in rheumatoid arthritis. A two year prospective follow-up

One hundred and thirty seven rheumatoid arthritis (RA) patients refractory to D-penicillamine and some of them (15%) refractory to other slow active drugs were treated with oral methotrexate (MTX) (10-15 mg weekly). After 12-24 months of treatment, 94 and 74 patients respectively showed a significant improvement as judged by duration of morning stiffness (p less than 0.0001), grip strength (p less than 0.0001), degree of joint swelling (p less than 0.01) and tenderness (p less than 0.0001) compared to pre-treatment values. This clinical improvement was also associated with a decrease of erythrocyte sedimentation rate (p less than 0.001), decrease of C-reactive protein (p less than 0.0001) and with improvement of anaemia (p less than 0.05). No changes were seen in rheumatoid factor titres. Seventy-four of the patients were followed for up to 24 months. Thirty-one of them (23%) had complete remission and 43 (31%) had an excellent response. Adverse drug reaction during MTX therapy included: elevated liver enzymes in 34 patients, mucosal ulcers in 21, nausea and vomiting in 8, diarrhoea in 4, leukopenia in 2, interstitial pneumonitis in one, intestinal bleeding in one and finally septic arthritis in another patient. The majority of these side effects were resolved without sequelae. However, 15 patients (11%) with adverse drug reactions had to discontinue the treatment. Forty-one of our patients who received a cumulative mean dose of MTX of 1550.5 +/- 235.5 mg underwent a percutaneous liver biopsy. Ten patients had normal tissue, 12 had minimal changes, 13 nonspecific changes and 6 patients had mild fibrosis.(ABSTRACT TRUNCATED AT 250 WORDS)

Transfusion history, T cell subsets and natural killer cytotoxicity in patients with colorectal cancer

Blood transfusions are associated with clinical phenomena which are attributable to immune suppression. Since suppression of immune function is associated with a high risk of spontaneous malignancies, we studied T cell subsets and natural killer (NK) cytotoxicity in colorectal cancer patients and correlated the results with patients' transfusion histories. Twelve percent (14) of the 115 patients had been transfused an average of 19 years previously. Recipients of blood transfusions had low levels of peripheral lymphocytes (p = 0.191), T cells (p = 0.015), helper cells (p = 0.016) and suppressor cells (p = 0.2651) compared to previously untransfused patients. NK cytotoxicity was also significantly reduced in transfusion recipients although NK cell numbers were comparable in both groups. These results support previous studies indicating that blood transfusions cause lifelong immune modulation in the recipient. Since blood transfusions have numerous beneficial effects and immune modulation is often beneficial, longitudinal studies are necessary to define the lifetime risks and benefits.

Primary central nervous system lymphoma

Primary lymphoma of the central nervous system (CNS), including reticulum cell sarcoma, microglioma, and histiocytic lymphoma, represents less than 1% of all primary brain tumors. In the last 10 years, this tumor has tripled in frequency in the nonimmunosuppressed population. By 1991, the tumor will be the most common neurological neoplasm by virtue of the increase in sporadic occurrence and in the acquired immunodeficiency syndrome (AIDS) population. Three percent of AIDS patients will develop this tumor either prior to AIDS diagnosis or during their subsequent course. In addition to acquired immunosuppression, patients with inherited disorders (such as Wiskott-Aldrich syndrome, severe combined immunodeficiency, and X-linked immunodeficiency) and other acquired disorders of the immune system are predisposed to the development of CNS lymphoma. Immunological studies have suggested a role for Epstein-Barr virus in the production of this tumor. Although subtypes exist, non-Hodgkin's lymphoma of the CNS most commonly consists of histiocytic cells or large immunoblastic cells bearing B cell surface markers in close proximity to the lateral and third ventricles. Sixty percent of these deposits are multiple, and subarachnoid invasion is seen in one-quarter of patients. Vitreous involvement of the eye occurring prior to and during the course of CNS lymphoma has been noted in up to 25% of patients. The involvement of multiple areas of the neuraxis, the eye, and multiple intracranial sites often occurs in the absence of obvious systemic lymphoma. Therapeutic trials of brain radiation therapy are associated with median survivals of less than 1 year. Uniform complete responses of intracranial deposits are recorded following chemotherapy with high-dose intravenous methotrexate, CHOP (cyclophosphamide, hydroxydaunomycin/doxorubicin, Oncovin (vincristine), and prednisone), high-dose cytosine arabinoside, and intra-arterial methotrexate with barrier modification.

Lethal skin cancers in hairy cell leukemia (two case reports)

2 patients with hairy cell leukemia (HCL) complicated by multiple cutaneous and other malignancies are described. The second malignancies behaved in a much more aggressive fashion than would be expected in an immunocompetent population, and were lethal in both patients. The literature regarding second malignancies in immune compromised patients, and in HCL in particular, is reviewed.

Diagnostic importance of immunological markers in lymphoma involving the central nervous system

In an elderly woman, lymphoma involved the central nervous system and unusual nonlymphoreticular sites. Cerebrospinal fluid cell surface marker studies revealed a clone of malignant B cells. Studies of peripheral blood demonstrated a systemic disturbance of immune regulation similar to Epstein-Barr virus infections and the acquired immunodeficiency syndrome.

Leukemogenesis related to chemotherapy of ovarian carcinoma: a review with three new case reports

A review of the literature of 68 case reports of acute leukemia following ovarian cancer is presented and 3 new cases are reported. Review of the literature revealed 34 patients received chemotherapy and radiotherapy, 32 patients received chemotherapy alone, 1 patient had only surgery, and the radiation status of the remaining patient is unclear. Chemotherapy usually consisted of alkylating agents often given in high dose and for long durations. The reported risk for developing acute leukemia after treatment of ovarian cancer ranges from 21 to 175 times that of the general population with a prevalence range in treated patients of 0.8 to 2.7%. The median interval from initiation of therapy to the development of leukemia is shortened from 54.2 to 41.1 months if radiation therapy is used in addition to chemotherapy. The patients typically exhibit a brief preleukemic phase and poor survival with death occurring 3 to 5 months after diagnosis of leukemia. Proposed mechanisms for leukemogenesis are presented.

Aggressive large cell lymphoma of the ileum after long-term cyclophosphamide therapy for breast carcinoma

A middle-aged woman was treated for breast carcinoma with postoperative adjuvant chest wall irradiation, followed four and seven years later with therapy to spinal ports for palliation of metastatic disease. For the next three and a half years, she received oral cyclophosphamide on a daily basis to a total of more than 110 g. Twelve years after diagnosis and five years after the start of chemotherapy, an aggressive, large cell lymphoma of the ileum developed, with poor response to conventional therapy. This may represent the first patient with breast carcinoma in whom a treatment-induced non-Hodgkin's lymphoma has developed.

Low dose oral methotrexate in rheumatoid arthritis: an uncontrolled trial and review of the literature

New therapeutic alternatives are needed for patients with progressive RA unresponsive to gold or D-penicillamine. Azathioprine and cyclophosphamide can be effective but have been linked with the development of lymphoreticular malignancies. In an effort to exploit a less toxic agent, we have been impressed by the results and minimal toxicity of low dose oral MTX. Extensive application of this regimen in psoriasis and psoriatic arthritis indicates that low dose MTX does not have an unusual risk for developing cancer. In addition, prior experience with other rheumatic disorders and preliminary studies on the mechanism of action suggest a potential value in RA. We present our initial retrospective results in 28 patients with refractory RA given low dose oral MTX over the past 2.5 yr. An apparent positive response was noted in 19 of these patients (67%) and is similar to the experience of other clinicians. At the same time, the toxicity has been low and, with one exception, amenable to dose modification. Methotrexate in various regimens is being increasingly employed in refractory RA. Issues concerning the pharmacology and potential toxicity are, therefore, important. These topics are reviewed with emphasis on low dose therapy and hepatotoxicity. Despite the encouraging preliminary results it is unclear whether MTX can prevent erosions or improve long-term function and quality of life in RA. There are still no controlled perspective studies comparing MTX to placebo or other immunosuppressive agents in RA. Although short-term toxicity is low, long-term toxicity, especially hepatic, is uncertain. As a result, a controlled, long-term prospective study is necessary.

No increase in second tumors after cytotoxic chemotherapy for gestational trophoblastic tumors

We investigated the incidence of second tumors after cytotoxic chemotherapy in 457 long-term survivors treated for choriocarcinoma or an invasive mole between 1958 and 1978. Treatment was given according to regular intermittent schedules and over a mean period of four months, with no maintenance. Methotrexate was given to all but two patients, and 261 (57 per cent) also received other cytotoxic drugs, most commonly dactinomycin, vincristine, cyclophosphamide, mercaptopurine, and 6-azauridine. After a mean period of 7.8 years since the beginning of treatment and a total of 3522 patient-years of risk, second neoplasms had developed in only two women (acute leukemia in one and carcinoma of the breast in the other). This figure is less than the number of cases of cancer that would have been expected (3.5) in this group and suggests that the use of methotrexate as chemotherapy for choriocarcinoma is not carcinogenic in the medium term.

Uveal melanomas presenting during pregnancy and the investigation of oestrogen receptors in melanomas

We observed a young woman who showed growth of a choroidal melanoma over the course of 2 pregnancies, with subsequent enucleation of the eye. This is the first such documented case. In addition 4 other women with uveal malignant melanomas presented during pregnancy. This observed number of pregnancies (5) was greater than the expected number (2.1) among women of childbearing age who underwent enucleation with subsequent analysis in our pathology laboratory. However, this difference was not statistically significant. Further, more females 44 years of age or younger underwent enucleation for malignant melanoma than men of comparable age. Evaluation of these cases led us to propose that there is a subset of patients whose ocular melanomas are hormonally responsive. We therefore analysed uveal melanoma and choroidal tissue from 7 patients, including one of the pregnant women, for the presence of oestrogen receptors. No specific oestrogen binding was found. The possibilities that other hormones are involved or an immunological mechanism is operative are discussed.

Late side effects of chemotherapy in ovarian carcinoma: a cytogenetic, hematologic, and statistical study

Late side effects of chemotherapy were studied in 51 women who had received at least 300 mg of melphalan for ovarian cancer and had survived for at least three years. Hematologic, statistical, and cytogenetic methods were employed. Six cases of iatrogenic leukemia were found. They appeared to represent a hematologic entity that is fairly difficult to recognize. The risk of iatrogenic leukemia in women who survived for three years or more after melphalan treatment was calculated to be 950 times greater than the leukemia risk in the total female population. The cytogenetic changes were studied with three methods focused on sister chromatid exchange, chromosome aberrations, and DNA damage. The sister chromatid exchange frequency showed a marked increase, but it was corrected within a few months. Chromosome aberrations expressed by chromosome rearrangements were increased in the peripheral lymphocytes and may persist for several years. The frequency of DNA stand breaks was decreased indicating the presence of DNA cross-links. Any of these types of genetic alteration could be the initiating event in carcinogenesis.

Cervical intraepithelial neoplasia in immunosuppressed women after renal transplantation

All 26 immunosuppressed renal transplant females attending the Renal Unit at the Western Infirmary, Glasgow were screened by cervical cytology and colposcopy for evidence of cervical neoplasia. Five patients (19.2%) were discovered to have cervical intraepithelial neoplasia, confirming the expected increase in this 'at risk' group. Regular cervical screening in these immunosuppressed women is recommended strongly.

Induced acute non-lymphocytic leukemia following long-term chemotherapy: a study of 20 cases

Twenty individuals developed acute non-lymphocytic leukemia (ANLL) following long-term chemotherapy for other disorders. The primary disorders included non-Hodgkin's lymphoma (five), Hodgkin's disease (five), carcinoma (four), multiple myeloma (three), chronic leukemia (two), and rheumatoid arthritis. Leukemia developed from 11-132 months (mean approximately 60 months) following institution of chemotherapy and all cases have occurred since 1974. Pre-leukemic cytopenias were present in 15 individuals. Fifteen of the 20 patients had chromosome analyses and 14 were abnormal. The leukemia was invariably refractory to chemotherapy with a median survival of only two months. Of the patients autopsied, only one individual had any evidence of the primary malignancy. This study illustrates the need for surveillance for secondary ANLL following long-term chemotherapy with/without radiotherapy. Duration of optimal chemotherapy for the primary disease must be determined by control trials and weighed against the risk of developing a secondary leukemia.

A new approach in the immunotherapy of carcinoma of the colon and rectum

Although the therapy of carcinoma of the colon and rectum has been investigated, little progress has been made in prolonging the survival in these patients. Specific active immunotherapy may provide the answer. Previous investigators have shown that colorectal cancer elicits an immune response and may be susceptible to immunologic manipulation. My laboratory has shown that a live vaccinia virus-augmented (vaccinia oncolysate) tumor cell vaccine is safe and may be worthwhile in the surgical adjuvant treatment of colorectal cancer. Nine patients with advanced cancer were treated. 0/9 showed adverse effect and 3/9 showed lack of progression of disease. Randomized prospective trials are now underway.

Selective immunodeficiency and malignant lymphoma of the central nervous system. Possible relationship to the Epstein-Barr virus

This report presents the findings of a study of a 17-year-old male with a selective immunodeficiency to the Epstein-Barr virus, who died of a malignant lymphoma following clinical infectious mononucleosis. Autopsy findings and immunohistochemical techniques demonstrated a malignant lymphoma with B-lymphocyte characteristics which primarily involved the central nervous system (CNS). The relationship of the Epstein-Barr virus to lymphoproliferation is discussed.

Suppression of phytohemagglutinin response by fungi from a "leukemia" house

Fungal isolates from the house of a husband and wife who both developed acute myelomonocytic leukemia were assayed for effects on the in vivo response to phytohemagglutinin in guinea pigs. Skin responses to intradermal phytohemagglutinin were measured following injections of sterile fungal extracts. Isolates of Penicillium canescens, Curvularia, Fusarium sambucinum, Fusarium equiseti and Trichoderma koningii from the leukemia-associated house depressed the responses to phytohemagglutinin, but none of the fungal isolates obtained from a nearby control house depressed responses to phytohemagglutinin. Such environmental agents may contribute to development of malignancy by suppression of immune responses.

Coexistence of leukemic reticuloendotheliosis and histiocytic lymphoma: a case report

A 65-year-old woman had pancytopenia, splenomegaly, and an inaspirable bone marrow. Diagnostic evaluation demonstrated that she had both leukemic reticuloendotheliosis (LRE), or hairy cell leukemia, and an additional lympho-reticular neoplasm, most likely a "histiocytic" lymphoma. The diagnosis of LRE was based on the histopathology of spleen tissue and of a bone marrow biopsy specimen. The diagnosis of diffuse "histiocytic" lymphoma was based on the histopathology of a splenic hilar and a mesenteric lymph node, tumor nodules in the kidney and spleen, and tissue from a mass obstructing a ureter. This is the first well-documented association of a second lympho-reticular neoplasm with LRE. Even relatively gently treatment of the "histiocytic" lymphoma resulted in fatal pancytopenia, illustrating the restricitons on therapy imposed by the marrow impairment due to the LRE.

Possible role of mumps virus in the etiology of ovarian cancer

Eighty-four ovarian cancer (OCa) patients and 84 controls with nonmalignant conditions matched by age and ethnic origin were interviewed with regard to clinical mumps history and their sera were tested for complement fixation (CF) mumps antibodies. OCa patients differed from the controls in the response to past mumps infection in two respects: 1) They appeared to be more likely to have developed subclinical mumps as evidenced by a lower rate of clinical mumps history in the presence of serological evidence of similar infection rates among those with positive and those with negative clinical mumps history. 2) They tended to present lower persistent mumps CF antibody titers. These results may be interpreted to indicate that an immunological incompetence enables the development of OCa possibly through a direct etiologic role of mumps virus.

Histiocytic lymphoma of the ileocecal region after chemotherapy for multiple myeloma

Histiocytic lymphoma of the ileocecal region developed in a patient with multiple myeloma following successful long-term alkylating agent therapy. Five and one-half years after the diagnosis of myeloma, while in remission on cyclophosphamide therapy, the patient experienced severe abdominal right lower quadrant pain due to a large cecal lymphoma. A right hemicolectomy was performed with relief of symptoms. However, 9 months later, while still asymptomatic, routine physical examination revealed a recurrent right lower quadrant tumor. Radiation therapy decreased the size of the mass, but five months later partial small bowel obstruction occurred because of recurrent lymphomatous infiltration. The patient died 7 years after the diagnosis of myeloma with extensive abdominal lymphoma. There was no evidence of recurrent myeloma after the initial remission on cyclophosphamide therapy. This patient adds to the growing literature of a second malignancy occurring after prolonged successful chemotherapy of a primary neoplasm.

The effect of levamisole on DMBA-induced carcinogenesis in the hamster cheek pouch

The effect of levamisole on DMBA-induced carcinogenesis in the cheek pouch of the hamster was studied. Findings indicate that levamisole modified the response of the pouch to DMBA at six weeks, while this effect was not maintained after 12 weeks of DMBA application.

Genes, pollutants and human diseases

The use of traditional Western concepts of disease (i.e. the ‘germ’ theory) has guided the use of scientific knowledge and technologies in the Control of acute infectious diseases (Gori & Peters, 1975; Trosko & Chang, 1978c). The intervention of all sorts of technologies has prolonged the life expectancy, allowing more people to reach the limit of what appears to be a rather fixed life-span (Hayflick, 1976). At the same time, human beings have used technologies to alter out dependence on the natural enviroment We intervene on many levels to minimize threats to our dependence on natural forces for food (e.g. agricultural technology, food additives), for water (e.g. wells or dams), for health (e.g. instituting sanitary measures or using drugs), for protection against the elements (e.g. wearing clothes, building homes with heaters and air conditioners) and for pleasure (e.g. snowmobiles, etc.). It is now extremely clear that much of the ‘effluents of our technological affluence’ can be harmful to living systems.

Ovarian carcinoma terminating in acute nonlymphocytic leukemia following alkylating agent therapy

Rapidly fatal acute myelogenous leukemia (AML) occurred in a woman with advanced (Stage III) ovarian carcinoma who was treated with thiotepa for 30 months. This patient was 1 of 10 long term survivors and represented less than 2% of patients with advanced ovarian carcinoma with regional metastases who received long term chemotherapy during the period 1947-1975. Acute leukemia developed 44 months after initial diagnosis and was preceded by a 10 month period of pancytopenia following cessation of thiotepa. The leukemia did not respond to treatment and the patient expired 3 weeks after its onset. At autopsy, leukemic infiltration of organs was seen, but there was no evidence of carcinoma. A review of the literature suggests that the development of AML reported in ovarian cancer patients is related to alkylating agent therapy.

Acute leukemia after chemotherapy (melphalan)

During the years 1966-1973 474 patients with ovarian carcinoma were treated with melphalan. Of these, 48 patients received at least 300 mg melphalan and survived at least 3 years; four cases of acute leukemia were found among these 48 patients. All cases belonged to a group of 12 cases receiving 800 mg melphalan or more.

Familial occurrence of colon and uterine carcinoma and of lymphoproliferative malignancies: clinical description

Carcinoma of the colon occurred in four generations of a family, including two of three siblings of one generation and eight of 19 members of the next generation. In addition, uterine cancer or lymphoproliferative malignancies were found in two family members. Of 41 members of the fourth generation, two were found to have colon cancer and one had malignant lymphoma. Clinical features were similar to those patients with "cancer family syndrome." Although a precise genetic mechanism is uncertain, it appeared to be transmitted as an autosomal dominant character.

Induction of hapten-specific cell-mediated immunity in rhesus monkeys treated with adsorbent purified antilymphocyte antibody

Rhesus monkeys were treated with sufficient amounts of rabbit antilymphocyte sera and immunoadsorbent purified antilymphocyte antibody to retain full-thickness skin grafts 23 and 29 days respectively. During this immunosuppressed period hapten-specific cell-mediated immunity was induced in six of seven rhesus monkeys immunized with p-azophenylarsono-N-acetyltyrosine (R-tyr) in complete Freund's adjuvant. These observations suggest that in rhesus monkeys different populations of T cells may be responsible for cutaneous sensitization to antigen and rejection of skin grafts.

Adenocarcinoma of the small bowel in association with regional enteritis. Four new cases

Four cases of carcinoma of the small bowel following chronic regional enteritis are presented. Search of the medical literature revealed 31 other cases reported up to the present. We must entertain the possibility that chronic regional enteritis may predispose to the development of cancer of the small bowel.

Morphological observations of immunobiology of laryngeal cancer. Evaluation of the defensive activity of immunocompetent cells present in tumour stroma

A series of 104 patients with squamous cell carcinoma of the larynx was studied with regard to tumour-host interaction. Prognostic evaluation was based upon histologic grading and morphological evidence of host immune response, judged by the presence and degree of lymphocyte and plasma cell infiltration in tumour stroma. Histologic grade and lymphoplasma-cellular infiltration do correlate with the 5-year survival. The immune response, however, seems to be a favourable prognostic sign only for well differentiated tumours; in our series, all poorly differentiated neoplasms showed minimal or no cellular response. The survival rate increases with the increasing intensity of cellular response within each class of tumour cell differentiation. Small lymphocytes are the basic elements of cell-mediated immune response. After tumour antigenic stimulation they change into immunoblasts which in turn would produce "committed" lymphocytes which would recognize and destroy tumour cells.