Further observations on the inhibition of tumor growth by Corynebacterium parvum with cyclophosphamide. I. Variation in administration of both agents

Evaluation of the worth of corynebacterium parvum in conjunction with chemotherapy as adjuvant treatment for primary breast cancer. Eight-year results from the National Surgical Adjuvant Breast and Bowel Project B-10

During the 1970s, information obtained from animal tumor models and from patients with a spectrum of solid tumors indicated the worth of a variety of immunostimulating agents. These findings provided a biological and clinical rationale for conducting randomized trials to evaluate the worth of those agents. Consequently, in May 1977 the National Surgical Adjuvant Breast and Bowel Project (NSABP) implemented a randomized trial to determine whether Corynebacterium parvum (C. parvum, CP) plus chemotherapy would be more effective than chemotherapy alone in prolonging the disease-free survival (DFS) and survival (S) of patients with primary operable breast cancer and positive axillary nodes. The results of that trial through 8 years of follow-up fail to indicate that treatment with CP used in conjunction with l-phenylalanine mustard (L-PAM) plus 5-fluorouracil (PF) results in a better DFS and S than that observed after chemotherapy alone. Use of the immunomodulator has instead resulted in a poorer, but not statistically significant, outcome. Despite adjustments made to account for any imbalance in distribution of prognostic factors between the two treatment groups and despite considering treatment compliance as a factor, the unfavorable outcome persisted. A high incidence of fever and chills was associated with the administration of CP. The administration of hydrocortisone before each CP treatment reduced the frequency of those and other systemic effects. The failure to demonstrate a benefit from CP is in keeping with the failure of other nonspecific stimulating agents to contribute to the creation of a new paradigm for the treatment of breast cancer.

The therapeutic effects of an immunopotentiator, PS-K, on 3-methylcholanthrene-induced autochthonous tumors in C57BL/6 mice in combination with the surgical removal of primary sites

We investigated the therapeutic effects of an immunopotentiator PS-K on recurrent or metastatic tumors observed after the surgical removal of MCA-induced primary tumors in autochthonous C57BL/6 mice and on the survival time of treated mice. The MST of mice treated with PS-K at various times (59.8-63.4 days) was prolonged as compared with that of mice treated by surgery alone (48.6 days). Local recurrence of tumors was found in 36 of 66 mice (54.6%) treated by surgery alone, whereas it was inhibited significantly (P less than 0.05) when treatment with PS-K was started 1 day after the surgery and occurred in 22 of 64 mice (34.4%) when PS-K was given for 5 days in 1 week, or in 22 of 66 mice (33.3%) when PS-K was administered twice a week for 7 weeks. The MSTs of mice with local recurrence were also found to be prolonged as compared with those of mice treated by surgery alone (54.8-67.5 days vs 49.8 days). The MSTs of mice without tumor recurrence were also prolonged significantly (P less than 0.05-0.001) by combinations of PS-K at various times, although most of the mice died of metastatic tumors even in the groups of mice where a combined treatment with PS-K had been administered. The above findings suggest that the administration of PS-K inhibits the growth of recurrent or metastatic tumor cells in autochthonous mice after the surgical removal of the primary tumors.

Cellular mechanisms underlying the adjuvant activity of Candida albicans in a mouse lymphoma model

Inactivated Candida albicans (CA) possesses strong anti-tumor activity when combined with cytoreductive chemotherapy in a mouse lymphoma model. In the present study, experiments were performed in order to elucidate the mechanism(s) underlying CA immunoadjuvant activity. In vivo chemotherapy studies proved that the synergistic anti-tumor effects were lost in athymic (nu/nu) mice and were also abrogated by radiations. In vitro tests did not suggest a major involvement of natural cytotoxic effectors such as macrophages and natural killer cells nor did CA effects appear to be mediated by induction of interferon. It was concluded that the immunoadjuvant activity of CA largely relies on host responses against tumor-associated transplantation antigens with no major involvement of natural resistance immune mechanisms.

Analysis of therapeutic effect in experimental chemoimmunotherapy for rat ascites tumor

The lyophilized, squalene-treated Nocardia rubra cell wall skeleton (N-CWS) was confirmed to produce tumoricidal peritoneal macrophages resulting in inhibition of tumor growth when injected locally into the syngeneic ascites fibrosarcoma, AMC 60 in ACI/N rats. Furthermore, N-CWS was found to augment therapeutic effect when administered repeatedly after a single local injection of mitomycin-C (MMC). To analyze the effects, various in vitro cytolysis assays were performed using N-CWS-activated peritoneal macrophages. When tumor target cells were exposed in vitro to MMC, the resulting cytolysis in the presence of N-CWS-activated macrophages was similar to cytolysis of intact target cells. On the other hand, when N-CWS-activated macrophages were exposed to MMC, the tumoricidal activity was lost significantly, depending on exposure to MMC. When tumor target cells and N-CWS-activated macrophages were simultaneously exposed to MMC, tumor-cell cytolysis was strikingly depressed. In the final experiment, combined injection of MMC and N-CWS into the ascites tumor resulted in remarkable increases not only in peritoneal exudate cell number, but also in in vitro tumoricidal activity of peritoneal macrophages as compared to those induced by either agent alone. In addition, the production of tumoricidal macrophages by IP injection of MMC alone was also noticeable, as described previously. These results possibly indicate the involvement of macrophage activation in induction of therapeutic effect in chemoimmunotherapy.

A trial of imidazole carboxamide and corynebacterium parvum in disseminated melanoma: clinical and immunologic results

Nonspecific immunotherapy with monthly intramuscular (IM) injections of Corynebacterium parvum has been investigated in patients with disseminated melanoma. Forty-nine patients were randomized to receive either imidazole carboxamide (DTIC) alone or DTIC plus C parvum. A 24% overall objective response rate was observed, with no significant difference between the response rate or survival of the two treatment groups. Immunologic studies revealed no significant difference between the two groups. One patient undergoing chemoimmunotherapy demonstrated profound pancytopenia which responded to cessation of therapy, but toxic reactions were otherwise minimal. No advantage was obtained by adding IM injected C parvum to standard chemotherapy in the treatment of disseminated melanoma.

Harmful effects of i.v. Corynebacterium Parvum given at the same time as cyclophosphamide in patients with squamous-cell carcinoma of the bronchus

The effects are reported of a combination therapy of i.v. C. parvum and cyclophosphamide on the survival time and immune responses of patients with inoperable squamous-cell carcinoma of the bronchus. The immune status of the patients was evaluated by determining the antibody response to C. parvum, the E and EAC rosettes, the PHA response of blood lymphocytes, the skin-test reactivity to Candida and PPD, the response to DNCB and the chemotaxis and NBT-dye reduction capacity of neutrophil leucocytes. The survival time of patients treated with the combination therapy was found to be significantly shorter than that of untreated patients and of those receiving cyclophosphamide only. Severe side effects were observed after C. parvum infusions, with no decrease on repeated administration. The effect of C. parvum on the different immune parameters of cyclophosphamide-treated patients was negligible, though there was a normal antibody response to C. parvum.

Cytostatic effects of activated macrophages on tumor target cells: inhibition of cytotoxic action of ARA-C

Studies carried out to explore further the cytotoxic effects of activated macrophages from mice treated with Corynebacterium parvum revealed that their effect on the EMT-6 line of tumor target cells was limited solely to cytostasis with no evidence of a cytocidal effect. In additional studies, the cytostatic effects of activated macrophages markedly reduced the cytotoxic effects of the chemotherapeutic agent cytosine arabinoside on EMT-6 target cells.

A trial of 5-fluorouracil and Corynebacterium parvum in advanced colorectal carcinoma

This study has confirmed that patients who have advanced colorectal carcinoma have impaired responsiveness to delayed-hypersensitivity skin testing, and also have elevated levels of serum IgM. Serial observations of delayed-hypersensitivity skin tests, total lymphocyte counts, T-lymphocyte counts, B-lymphocyte counts, and serum immunoglobulin levels failed to reveal any consistent pattern of responses in patients treated with either chemotherapy alone or chemoimmunotherapy. In 33 patients chosen at random to receive either 5-FU alone or 5-FU in combination with intramuscularly administered C. parvum, there was no evidence of objective response or influence on survival. Intramuscularly administered C. parvum, in the dose and schedule used, produced no evident immunologic or therapeutic effect.

Further observations on the inhibition of tumor growth by C. parvum with cyclophosphamide. VII. Effect of treatment prior to primary tumor removal on the growth of distant tumor

The present investigations were directed toward determining whether primary tumor manipulation prior to its removal is advantageous for the control of metastases and survival. Studies were carried out to ascertain whether 1) there is justification for delaying surgical removal of a primary tumor to permit preoperative administration of cyclophosphamide (CY) and/or C. parvum (CP) and 2) there is an advantage to administering the immunotherapy directly into a primary tumor. After operation, in all investigations, systemic CP and CY was used. Despite the putative similarity of animals, tumors and treatment regimens there was marked variation in response of tumors to therapy. No benefit was derived from administering preoperative immunotherapy alone. When operation was delayed to employ systemic immuno-chemotherapy, a slight improvement in the control of distant tumor was noted. The employment of preoperative intratumor immunotherapy led to a greater prolongation of survival and more inhibition of distant tumor growth than did immediate primary tumor removal or the use of preoperative systemic immunotherapy. The results suggest that there may be an advantage to delaying removal of a primary tumor so that it may be employed in therapeutic strategies directed toward control of metastatic disease.

Effect of immunochemotherapy on lymphocyte response of patients with gastrointestinal cancer

Patients with gastrointestinal cancer were treated with 5-fluorouracil (5-FU) in combination with a streptococcal preparation, OK-432, or without OK-432 before operation, and lymphocyte response to PHA was examined. Oral administration of 5-FU with or without intramuscular injection of OK-432 did not affect the response. However, treatment with cytostatic drugs in combination with OK-432 markedly augmented the lymphocyte response to PHA, but the cytotoxic activity of lymphocytes was not elevated.

Toxicity manifestations following intravenous Corynebacterium parvum administration to patients with ovarian and cervical carcinoma

Manifestations of clinical toxicity were evaluated following 341 courses of intravenous Corynebacterium parvum adjuvant immunotherapy in patients with ovarian and cervical carcinoma. Most patients exhibited symptoms of minor toxicity, which decreased in intensity as subsequent courses of therapy were administered. Temperature elevations to 38.5 degrees C. were the most objectively measured signs of toxicity but temperature elevations greater than 38.5 degrees C. occurred following only 20.5 per cent of the infusions. Blood pressure alterations were not a serious problem and no serious central nervous system or renal toxicity was noted. The minor side effects should not preclude the use of C. parvum as an immunopotentiating agent if it is shown to be beneficial in the treatment of human malignant disease.

Analysis of synergy between cyclophosphamide therapy and immunity against a mouse tumour

C3H/He and CBA/T6T6 mice which share the H2(k) haplotype were compared for their capacity to survive challenges with the C3H-derived fibrosarcoma BP8. It was found:(1) The tumour grows at the same rate with the same median survival time in matched groups of non-immunized mice from both strains after i.p. injection of tumour cells.(2) Cyclophosphamide (Cyclo) at 10 mg/kg will cure CBA mice which have received i.p. injections of 10(7) BP8, but this dose, and more intensive treatment with this drug, fails to cure C3H mice.(3) Injecting (125)IUdR-labelled tumour cells and counting (125)I loss by whole-mouse counting shows that the cytotoxic effect of Cyclo against BP8 is similar in the 2 mouse strains.(4) Cyclo itself does not cure CBA mice, for viable tumour cells are recoverable from the peritoneal cavity 10 days after CBA mice have received 10(7) BP8 followed by 10 mg/kg Cyclo.(5) CBA mice cured of BP8 ascites by Cyclo treatment will reject further i.p. inocula of BP8.(6) The strength of immunity induced by irradiated BP8 cells was directly related to the length of exposure to this antigen. An important aspect of Cyclo treatment is that it prolongs the period during which immunity may develop.(7) Immunization of CBA mice with heavily irradiated BP8, with or without Cyclo, failed to show that Cyclo depressed the capacity of CBA mice to develop cytotoxic immunity. There was some indication that animals immunized with irradiated cells plus drug did better than those with irradiated cells alone.(8) A single injection of irradiated BP8 cells into CBA mice induced weak cytotoxic immunity, as assessed by destruction of a subsequent challenge with BP8, but these mice died from tumour more rapidly than non-immunized controls. It is suggested from these data that immunological enhancement may not always be due to blocking of cytotoxic immunity.

Chemoimmunotherapy in disseminated melanoma and colorectal carcinoma

Non-specific immunotherapy with monthly intramuscular injection of Corynebacterium parvum has been investigated by randomized clinical trials in patients with advanced cancer. Thirty-six patients with disseminated melanoma were treated with either imidazole carboxamide (DTIC) alone or DTIC plus C.parvum. A 19% objective response rate was observed. The mean survival time was similar for both groups. Thirty-three patients with disseminated colorectal cancer were treated with either 5-fluorouracil (5FU) alone or 5FU plus C.parvum. No objective responses were observed. The mean survival time was similar for both groups. No advantage has been demonstrated in either tumour group by adding C.parvum to standard chemotherapy.

Observations following Corynebacterium parvum administration to patients with advanced malignancy. a phase I study

There has been increasing interest regarding the use of Corynebacterium parvum (CP) with other modalities in the management of primary cancer. Due to the paucity of specific information available relative to CP toxicity, a Phase I study was carried out in patients with advanced disease. The purpose of the investigation was not to evaluate the effect of CP on tumor growth. from 273 injections of CP in 40 patients it was observed that following intravenous (i.v.) infusion of CP: a) a febrile response and chills of considerable severity occured in almost all patients and did not appreciably diminish in intensity following repetitive administrations; b) nausea, vomiting, headache, and confusion were not infrequent; c) a "flu-like" syndrome lasting 24 to 48 hours occurred following almost all courses of CP; d) blood pressure elevations occurred on occasion and were related to the severity of other-side-effects; hyper- or hypo- tension was not a problem; e) ther were no anaphalactic reactions. Pretreatment with a single administration of 100 mg of hydrocortisone prior to CP infusion markedly and in some instances dramatically diminished the toxicity and made acceptable the use of i.v. CP on an outpatient basis. The use of i.v. CP in patients with cerebral metasteses may be hazardous. Subcutaneously administered CP resulted in a significant number of undesirable local reactions. Evaluation of delayed cutaneous hypersensitivity response, immunoglobulins, complement, and E- and EAC-rosette-forming cells during CP administration failed to demonstrate significant change from injection values. Results were similar whether hydrocortisone pretreatment was or was not employed. From the standpoint of toxicity it now seems appropriate to use i.v. CP, particularly following pretreatment with hydrocortisone, in a controlled clinical trial to evaluate its therapeutic effectiveness in the management of primary cancer.