Secondary Analysis of RRx-001 on the Incidence of Related Toxicities in Patients Treated with Concomitant Chemoradiation for Locally Advanced Head and Neck Cancer

PURPOSE/OBJECTIVE(S)

The results of an open-labeled Phase 2a trial (PREVLAR) suggested that infusion of RRx-001 (bromonitrozidine), a nitrogen-containing NLRP3 inhibitor and Nrf2 activator, attenuated the course and severity of severe oral mucositis (SOM) associated CRT (cisplatin/IMRT) in cancers of the mouth or OPC without impeding tumor response.1 Given its mechanism of action and the shared biology of radiation injury pathogenesis among other exposed tissues, we investigated the potential halo effect of RRx-001 on other regimen-related toxicities.

MATERIALS/METHODS

PREVLAR was a multi-center, open-label randomized trial in which patients (n = 46) having locally advanced, histologically confirmed SCC of the OC or OPC were centrally randomized to one of four arms. Arms 1-3 received 2 weekly doses of RRx-001 (4 mg/dose) beginning 2 weeks before the start of CRT. Arm 2 (n = 11) received 2 additional RRx-001 infusions during weeks 2 and 5 and patients in Arm 3 (n = 13) received weekly RRx-001 for the first 6 weeks of CRT. 10 mg of dexamethasone was administered before RRx-001 infusions. Arm 4 (n = 10), the control, received CRT only. Adverse events (AEs) were assessed using CTCAE v5. All patients received standard regimens of IMRT (daily fractions of 2-2.2 Gy/minimum cumulative dose of 55 Gy) plus either weekly or tri-weekly cisplatin.

RESULTS

Consistent with the observation that RRx-001 was most efficacious in attenuating the course of SOM when administered only prior to CRT (Arm 1) or prior to CRT with additional dosing on weeks 2 and 5 (Arm 2), compared to Arm 3 or control, the same dosing schedule appeared to be impactful on signs and symptoms of radiation-associated damage with tissues such as salivary glands and skin (Table 1). In particular, compared to control patients, patients in Arms 1 and 2 had a lower incidence of dry mouth (none vs. 60%), dysphagia (none vs. 70%), salivary duct inflammation (none vs. 30%), candida infection (9.1% vs 40%), radiation associated skin injury (Arm 1 none, Arm 2 18.2%, control 70%) and weight loss (none vs. 50%) as examples.

CONCLUSION

In this small proof of concept trial, RRx-001 infusion resulted in a reduction of multiple, biologically-related, side effects associated with a standard chemoradiation regimen used to the treatment of head and neck cancers. KEVLAR, a larger Phase 2b trial is planned to begin enrollment in Q4 of 2023 at about thirty sites in North America.

Oral leukoplakia remains a challenging condition

Crispian Scully had many interests in the realm of oral diseases. But oral leukoplakia was one that piqued his curiosity when he was still an academic neophyte and remained a topic which he studied throughout his enormously productive career. It is easy to understand why. While the clinical manifestations of oral leukoplakia are common, we still do not fully understand why one version of the condition is benign, while another, similar in appearance, progresses to a malignancy. The diagnosis of oral leukoplakia is based on expert clinical and histopathological examamination. Management and treatment of leukoplakia remain challenging especially for large lesions and the proliferative subtype. This review aims to provide a general overview on leukoplakia, explore current challenges in its diagnosis and management and discuss the opportunities to better understand the condition.

On the pathogenesis of mTOR inhibitor-associated stomatitis (mIAS)-studies using an organotypic model of the oral mucosa

OBJECTIVE

mTOR inhibitor treatment of solid cancers is associated with mTOR inhibitor-associated stomatitis (mIAS) a common, significant, dose-limiting toxicity, with aphthous-like lesions. Our objective was to assess the utility of a new organotypic model in defining mIAS' pathogenesis.

MATERIALS AND METHODS

The effect of everolimus on organotypic human oral mucosa was studied. Sterile specimens were assessed 24 and 48 h after exposure to varying concentrations of everolimus. Morphologic changes and measures of apoptosis, proliferation, and levels of six Th1 and Th2 cytokines were studied.

RESULTS

Following a 24-h incubation, concentrations of 500 ng ml^-1 of everolimus resulted in histological changes consistent with epithelial injury, disorganization and pre- or early apoptosis, increased TUNEL-positive staining (P < 0.05) and reduced PCNA-positive staining cells (P < 0.001) and increased levels of IL-6 (P < 0.0001), IL-8 (P < 0.01), and IFN-γ (P < 0.09).

CONCLUSIONS

Everolimus elicited epithelial damage manifest by morphologic changes, increased apoptosis, and decreased proliferation with concurrent release of keratinocyte-derived pro-inflammatory cytokines in the absence of bacteria. The extent of the effect was concentration and time dependent. These results suggest that mIAS is likely initiated by direct epithelial injury, independent of the microbiome. Keratinocyte cytokine release could likely play a role in accelerating an inflammatory infiltrate.

A phase II study (ARCHER 1042) to evaluate prophylactic treatment of dacomitinib-induced dermatologic and gastrointestinal adverse events in advanced non-small-cell lung cancer

BACKGROUND

ARCHER 1042, a randomized phase II trial, explored the impact of prophylactic treatment on select dermatologic adverse events of interest (SDAEI), diarrhea, and mucositis associated with dacomitinib, an oral irreversible pan-human epidermal growth factor receptor (HER) inhibitor, in development for advanced non-small-cell lung cancer (NSCLC).

PATIENTS AND METHODS

Patients with advanced NSCLC treated with dacomitinib were enrolled in two cohorts. Cohort I patients were randomized 1:1 to receive oral doxycycline or placebo (4 weeks). Cohort II patients received oral VSL#3 probiotic plus topical alclometasone. Primary end points for Cohorts I and II were incidence of all grade and grade ≥2 SDAEI in the first 8 weeks of treatment and quality of life (QoL) assessed by the Skindex-16 survey. Additional primary end points for Cohort II were incidence of all grade and grade ≥2 diarrhea and mucositis in the first 8 weeks of treatment; QoL regarding diarrhea and mucositis incidence was assessed by the modified-Oral Mucositis Daily Questionnaire.

RESULTS

Cohort I randomized 114 evaluable patients: 56 in the doxycycline arm, 58 in the placebo arm. Cohort II enrolled 59 evaluable patients. Doxycycline significantly reduced the incidence of grade ≥2 SDAEI by 50% (P = 0.016) compared with placebo. The incidence of all grade SDAEI was lower with doxycycline than with placebo but did not reach statistical significance. Doxycycline was associated with less deterioration in QoL compared with placebo. Alclometasone was associated with less deterioration in QoL compared with placebo but did not statistically significantly reduce the incidence of all grade or grade ≥2 SDAEI. VSL#3 did not reduce the incidence of all grade or grade ≥2 diarrhea and did not impact mucositis scores.

CONCLUSIONS

Doxycycline was effective as a prophylactic treatment for dacomitinib-induced grade ≥2 SDAEI. Both doxycycline and alclometasone reduced the negative impact in patient-reported dermatologic AEs. The probiotic was not effective for preventing diarrhea or mucositis.

Attenuation of radiation- and chemoradiation-induced mucositis using gamma-D-glutamyl-L-tryptophan (SCV-07)

OBJECTIVE

To evaluate the efficacy of a novel immunomodulating peptide (SCV-07) in attenuating the course of radiation-induced mucositis in an established animal model of oral mucositis (OM).

MATERIAL AND METHODS

In three separate experiments, golden Syrian hamsters received either an acute radiation challenge to the buccal mucosa of eight fractionated doses of 7.5 Gy of radiation over a 2-week-period, or a combination of acute radiation and cisplatin. In each experiment, animals were treated with varying doses or schedules of SCV-07 or placebo. OM was scored in a blinded fashion using digital images obtained during the experimental period.

RESULTS

We found that SCV-07 reduced the severity and duration of both acute and fractionated radiation-induced OM. Similarly, when radiation and chemotherapy were used to induce OM, treatment with SCV-07 significantly reduced the duration of ulcerative OM. The therapeutic benefit was dependent on both dose and schedule of administration.

CONCLUSION

Taken together, we found SCV-07 was able to modify the duration and severity of oral mucositis and was dependent on schedule and dose.

Effect of a mouth rinse formulation with human trefoil factor 1-secreting Lactococcus lactis in experimental oral mucositis in hamsters

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Background: Oral mucositis (OM) is a painful and dose-limiting toxicity of cancer chemotherapy and irradiation, characterized by breakdown of the oral mucosa. Trefoil factors (TFFs) are involved in protecting and healing mucosal tissue, and might thus represent a pharmacological tool for treatment of OM. Local delivery of recombinant TFFs at the oral mucosa by living, genetically modified Lactococcus (L.) lactis bacteria (ActoBiotics) seems a promising, safe and cost-effective clinical approach for the prevention and attenuation of oral mucositis. Methods: An environmentally contained Lactococcus lactis strain (AG013), engineered to express human (h)TFF1, was formulated for topical administration in the form of a mouth rinse. Efficacy of AG013 was assessed in a clinically relevant hamster model of acute, radiation-induced OM. The dosing regimen was 1.3 x 109 CFU/dose, once (qd) or three rinses (tid) daily, from day 0 (=day of radiation) to day 18. OM was scored from day 6 to day 28 using the WHO grading scale, and compared to the score of placebo-treated hamsters. The viability and survival of live L. lactis and the pharmacokinetics of the hTFF1 secreted were studied in healthy and OM hamsters. Results: Topical application of AG013 to the oral mucosa significantly reduced the severity and course of radiation-induced OM. In the AG013-treated groups, the number of animals days with ulcerative mucositis (grade 3 or higher) was significantly reduced to 27.5% and 30.8% (qd and tid respectively; P < 0.001), compared to 45.8 % in the placebo-treated group. Based on the observed survival and weight changes, AG013 appeared to be well-tolerated. Pharmacokinetic studies demonstrated that both living L. lactis and the hTFF1 secreted could be recovered from the administration site, for maximum 24 hours post-dosing, without systemic exposure. Conclusions: Oral administration of AG013 is safe and effective in reducing the severity and the course of OM in the hamster model, and therefore supports proof-of-concept for a mouth rinse formulation of AG013 to treat OM patients.

[Table: see text]

Network analyses to define chemotherapy toxicity clusters in patients with colorectal cancer (CRC)

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Background: CRC patients undergoing CT are likely to experience multiple concurrent toxicities. Rather than appearing singularly, the hypothesis that certain toxicities occur in clusters may suggest a common pathobiology. We used Markov networks (MN), a probabilistic graphical born at the confluence of statistics and artificial intelligence describing the dependency among set of variables, to identify clusters of CT-induced toxicities, to examine how clusters are connected to each other, and how single toxicities are related to a specific cluster. Methods: Using a standardized data collection tool, we retrospectively reviewed electronic medical charts of 300 consecutive CRC pts receiving FOLFOX, FOLFIRI or 5-FU to record baseline demographic and clinical information. Toxicities were recorded using NCI-CTC criteria during the first cycle of CT. Following the standard Bayesian approach, the MN clustering the CT-induced toxicities was learned from the data as the network with the highest posterior probability given the data. Results: The network, in which associations between toxicities are represented as links, identified five strongly-related symptom clusters: a constitutional cluster involving fatigue, anorexia, and weight loss; a gastrointestinal cluster where dehydration was the connector between diarrhea, constipation and bloating on a side and taste nausea and vomiting, taste alteration, fever and chills on the flipside; a dermatological cluster composed by dry skin, HFS, rash and itching and connected with hemorrhage/bleeding and wound complication toxicity. Furthermore, we noticed strong connections between cough, dyspnea and infection, with palpitation and pain and we detected another cluster where depression and anxiety where connected with cystitis. Conclusions: The application of network analyses to define CT-induced toxicity clusters is new. The technique was effective in defining the relationships between individual toxicities associated with cycle 1 therapy. The lack of randomness between the relationships defined by the network provides a strong suggestion that each cluster shares a common pathobiological basis, which may provide an opportunity for intervention.

[Table: see text]

Oral mucositis is associated with increased resource use among patients receiving treatment for cancers of the head and neck

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Background: Oral mucositis (OM) is the oral manifestation of mucosal injury (MUI), and is a common, bothersome, and treatment-interrupting toxicity of chemoradiation therapy for squamous cell cancers (SCC) of the head and neck. Retrospective studies have reported that OM increases healthcare resource use. We present interim results of an international, multicenter, prospective study undertaken to characterize the clinical and economic burden of OM in patients with cancers of the oral cavity (OC), oropharynx (OP), larynx (L) and hypopharynx (HP). Methods: Patients (pts) with histologically proven SCC of the designated anatomical sites, whose planned treatment included full-cycle conventional or intensity modulated (IM) radiation therapy (RT) with or without chemotherapy, were enrolled at least one week prior to the start of treatment. Pts completed the Oral Mucositis Daily Questionnaire (OMDQ), a validated questionnaire developed to document patient-reported symptoms of OM and MUI including mouth and throat soreness (MTS), at baseline and daily throughout RT. MTS was assessed using a 5-point numeric rating scale, ranging from 0 (“no soreness”) to 4 (“extreme soreness”). Results: Of the first 61 pts to complete RT, 72% had cancers of the OC or OP, 49% received IMRT with concomitant chemotherapy, and 68% were male. 95% of pts reported OM symptoms (MTS>0); 80% had one or more scores =2. Pts with OC or OP cancers reported more symptoms than those with L or HP tumors (mean maximum score: 3.3 vs 2.8; p= 0.12). MTS scores were positively related to levels of resource use. Conclusions: Symptoms of radiation-induced OM are positively correlated with levels of resource utilization in patients with head and neck cancers.

No significant financial relationships to disclose.

[Table: see text]

Palifermin (recombinant keratinocyte growth factor-1): a pleiotropic growth factor with multiple biological activities in preventing chemotherapy- and radiotherapy-induced mucositis

Oral and intestinal mucositis are among the most significant dose-limiting toxic effects of intensive cancer treatment and are associated with adverse clinical and economic outcomes. Palifermin (Kepivancetrade mark), an N-truncated recombinant human keratinocyte growth factor-1, is the first agent to be approved for prevention of oral mucositis. Keratinocyte growth factor, a potent epithelial mitogen, appears to play a major role in the healing process. Palifermin has multiple biological activities that appear to protect the mucosal epithelium and promote its early regeneration after irradiation- and chemotherapy-induced injury. These include inhibition of epithelial cell apoptosis and DNA damage, up-regulation of detoxifying enzymes and down-regulation of pro-inflammatory cytokines, as well as enhanced migration, proliferation and differentiation of epithelial cells. Palifermin reduces the incidence, severity and duration of oral mucositis in patients with haematological malignancies undergoing myelotoxic conditioning therapy and haematopoietic stem-cell transplantation. Clinical sequelae, including febrile neutropenia and resource use (opioid analgesia and parenteral feeding), are concomitantly reduced. Other potential applications being explored include use in the solid tumour setting, reduction of intestinal mucositis and reduction of GVHD in allogenic transplantation. Thus, the development of palifermin and other potential new agents for preventing chemotherapy- and radiotherapy-induced mucositis represents an important breakthrough in oncological supportive care.

Gene expression changes in peripheral blood cells provide insight into the biological mechanisms associated with regimen-related toxicities in patients being treated for head and neck cancers

Patients treated with radiotherapy are prone to a constellation of local and systemic toxicities including mucositis, xerostomia, fatigue and anorexia. The biological complexities and similarities underlying the development of toxicities have recently been realized. Mucosal barrier injury is one of the best studied, and gene expression patterns, based on animal tissue samples, have added to its understanding. While investigations gene expression based on tissue samples was valuable, its use precludes more generalizable conclusions relative to common pathogenic mechanisms. Additionally, attempting to define the kinetics of changes in gene expression by sequential sampling is pragmatically unrealistic. Our objectives were: 1. to determine if changes in gene expression could be detected during toxicity development using PBM from patients receiving chemoradiation; 2. to characterize the relationship of expressed genes using graph theory and pathway analysis; and 3. to evaluate potential relationships between the expression of particular genes, canonical pathways, and functional networks in explaining the pathogenesis of regimen-related toxicities.

DESIGN

Microarray analysis was performed using PBM-derived cRNA obtained before and 2 weeks after the initiation of chemoradiation in five patients with head and neck cancer who developed documented regimen-related toxicities. We created a database of those genes newly expressed at 2 weeks and evaluated their potential significance relative to toxicity, by canonical pathway analysis, compilation of regional networks around focus genes, and development of a model globalizing the individual functional networks. There was strong concordance between known pathogenic mechanisms of toxicity and the genes, pathways, and networks developed by our data. A role was elicited for unsuspected genes in toxicity development. Our results support the concept that radiation induced toxicities have common underlying mechanisms and demonstrate the utility of PBM as an RNA source for genetic studies. This methodology could be broadly applicable to the study of regimen-related toxicities.

Oral mucositis

Mucositis and xerostomia are the most common oral complications of the non-surgical therapy of cancer. Mucositis, a common sequel of radio- (DXR), chemo-(CXR) and radiochemo-therapy in patients with cancer, or patients requiring haemopoietic stem cell transplants (HSCT), has a direct and significant impact on the quality of life and cost of care, and also affects survival--because of the risk of infection. Apart from dose reduction, preventive and treatment options for mucositis are scarce, although multiple agents have been tested. Evidence suggests that cryotherapy, topical benzydamine and amifostine might provide some benefit in specific situations. The recombinant human keratinocyte growth factor Palifermin (Kepivance) was recently approved as a mucositis intervention in patients receiving conditioning regimens before HSCT for the treatment of haematological malignancies. A number of mechanistically based interventions are in various stages of development. Unfortunately, many other approaches have not been rigorously tested. This paper reviews the clinical features, prevalence, diagnosis, complications, pathogenesis, prophylaxis and management of mucositis.

A phase I/II double-blind, placebo-controlled study of recombinant human interleukin-11 for mucositis and acute GVHD prevention in allogeneic stem cell transplantation

Interleukin-11 (IL-11) decreases cytokine release and increases survival in murine BMT models. In these systems, it reduces gut permeability, partially polarizes T cells to a Th2 phenotype, down-regulates IL-12, prevents mucositis, and accelerates recovery of oral and bowel mucosa. We conducted a randomized double-blind pilot study of rhIL-11 administered with cyclosporine/MTX prophylaxis after cytoxan/TBI conditioning and allogeneic stem cell transplantation for hematologic malignancies. Patients received rhIL-11, 50 microg/kg subcutaneously daily or placebo in a 3:1 ratio. Treatment was administered prior to the start of conditioning and continued up to 21 days. The study was designed to assess safety with stopping rules for cardiac arrhythmias and mortality. Although projected to accrue 20 patients, only 13 patients (10 IL-11, three placebo) were enrolled because the early stopping rule for mortality was triggered. Of 10 evaluable patients who received IL-11, four died by day 40 and one died on day 85. Deaths were attributable to transplant-related toxicity. One of three placebo recipients died of suicide, the other two are alive. Patients receiving IL-11 had severe fluid retention and early mortality, making it impossible to determine whether IL-11 given in this schedule can reduce the rate of GVHD. Grade B-D acute GVHD occurred in two of eight evaluable patients on IL-11 and one of three patients on placebo. The primary adverse events of the study were severe fluid retention resistant to diuresis (average weight gain 9 +/- 4%) and multiorgan failure in five of 10 evaluable patients. The use of IL-11 as GVHD prophylaxis in allogeneic transplantation cannot be recommended as administered in this trial.

The biological basis for the attenuation of mucositis: the example of interleukin-11

Oral mucositis is common, painful, dose-limiting toxicity of drug and radiation therapy for cancer. In granulocytopenic patients, the ulcerations which accompany mucositis are frequent portals of entry for indigenous oral bacteria often leading to bacteremias or sepsis. The complexity of mucositis as a biological process has only recently been appreciated. The condition appears to represent a sequential interaction of the oral mucosal cells and tissues, pro-inflammatory cytokines, and local environmental factors in the mouth such as microorganisms and saliva. The recognition that the pathophysiology of mucositis is a multifactorial process has presented opportunities for intervention based on biological attenuation. Interleukin-11, a pleotropic cytokine, has a range of activities which is potentially relevant to mucositis. Consequently, it has been used successfully to modify the development, severity and course of mucositis in an animal model which closely mimics the equivalent human condition.

Alteration in the frequency, severity and duration of chemotherapy-induced mucositis in hamsters by interleukin-11

Ninety-five young, male Golden Syrian hamsters were randomly divided into five equally sized groups. One group served as a placebo control while the animals in the others received one of four doses of interleukin-eleven (IL-11) twice daily given by subcutaneous injection beginning on the first day of chemotherapy (day 0) and continuing to day 14. Mucositis was induced with 5-fluorouracil using a standard regimen of 60 mg/kg, intraperitoneally on days 0 and 2 followed by superficial mucosal irritation on day 4. Animals were evaluated daily beginning on day 6. Mucositis was assessed using a standardised technique in which randomly numbered daily mucosal photographs were scored by three blinded independent observers at the conclusion of the experiment. IL-11 favourably affected the frequency, severity and duration of mucositis. This phenomenon appeared to be dose dependent. Hamsters receiving 30 and 100 micrograms per day of IL-11 demonstrated significantly (P < 0.05) lower mucositis scores than did either the control or animals receiving 3 or 10 micrograms per day, although the latter had marginal beneficial effects. Additionally, survival was significantly better for hamsters receiving higher doses of IL-11 (85%) compared to the placebo control (46%). IL-11 administration also favourably affected weight loss. While stimulation of platelet production was noted in animals receiving IL-11, a lack of difference in bone marrow cellularity between test and control animals suggests that the mechanism by which IL-11 modifies mucositis is mediated at the epithelial or connective tissue level rather than through the marrow. The kinetics of IL-11 alteration of mucositis induction supports such a hypothesis. Further investigation is currently underway to establish a definitive mechanism by which IL-11 protects the oral mucosa.

Assessment of the need for treatment of postendodontic asymptomatic periapical radiolucencies in bone marrow transplant recipients

Oral screening and treatment of existing oral disease before bone marrow transplantation have been reported to decrease the incidence of infectious complications during bone marrow transplantation. Information about the adverse sequelae of specific preexisting oral diseases during bone marrow transplantation is lacking. The presence of postendodontic periapical radiolucencies may suggest recurrent or latent infection. The purpose of this study was to compare the effect of endodontic treatment with nontreatment of asymptomatic postendodontic periapical radiolucencies on the frequency of infectious oral complications during bone marrow transplantation. The records of 276 patients undergoing bone marrow transplantation examined between July 1988 and June 1991 were reviewed retrospectively. Twenty-three postendodontic periapical radiolucencies were identified in 8 women and 15 men. The mean age of patients was 41 years (range, 25 to 58 years). Fourteen of the lesions were untreated, and nine were treated before bone marrow transplantation. When outcomes of transplant complications were compared, neither increased systemic infection as measured by neutropenic days febrile nor local oral infectious complications were significantly different. These results suggest that nontreatment of asymptomatic postendodontic periapical radiolucencies does not increase the incidence of infectious complications during bone marrow transplantation.

Prevention and management of oral mucositis induced by antineoplastic therapy

Oral complications almost always occur as a consequence of treatment for head and neck cancer. In addition, approximately 40% of patients with nonhead and neck malignancies develop oral problems following exposure to chemotherapeutic agents and x-ray therapy. Patient-related risk factors for these problems include the type of malignancy, patient age, and the level of oral health before and during therapy. The authors discuss direct and indirect stomatotoxicity and present an overview of various methods of ameliorating and/or preventing oral mucositis.

Impact of improved dental services on the frequency of oral complications of cancer therapy for patients with non-head-and-neck malignancies

An earlier study by our group reported a frequency of about 40% for oral problems associated with cancer therapy for patients with non-head-and-neck malignancies. Since then, we have instituted a variety of preventive and treatment protocols aimed at the aggressive management of the mouth in patients being treated for malignant disease. In the present study we evaluated the frequency and nature of oral problems associated with cancer treatment in 495 patients treated for non-head-and-neck malignancies between 1978 and 1986. Our analysis indicates that the frequency of oral problems in the study population was 10.5%, compared to 38.7% in 1978. The specific nature and distribution of oral problems by diagnosis, by patient's age, and by type were remarkably consistent. Our results suggest that early and aggressive dental intervention in standardized protocols reduces the frequency of oral problems associated with cancer therapy.

Increased efficiency of immunotherapy using irradiated tumor cells

The efficacy of irradiated tumor cells combined with chemotherapy or non-specific immunostimulation with complete Freund's adjuvant was tested in a model of minimal residual tumor-bearing syngeneic mice. Male C57BL/6J mice were innoculated in the right rear leg with live tumor cells from a methylcholanthrene induced fibrosarcoma. The tumor was resected when it reached 0.7 cm in diameter and animals were treated with doses of irradiated tumor cells (XTC) from the primary tumor ranging in number from 1 X 10(3) to 9 X 10(3). Best survival was noted using 5 X 10(3) XTC combined with irradiated tumor cells of liver or pulmonary metastases origin, complete Freund's adjuvant or cytoxan. The combination of irradiated tumor cells of metastatic origin did not enhance the therapeutic effect of XTC alone. Freund's adjuvant was not of benefit in enhancing the efficacy of XTC. However, improved survival was noted when chemotherapy in the form of cytoxan was used to supplement XTC. Our data suggests that XTC is more efficacious as a mode of immunotherapy than are live tumor cells. The dose of XTC used is critical in determining its effect. Chemotherapy appears to enhance the benefit of XTC.

Polymorphonuclear leukocyte regulation of lymphocyte proliferation and differentiation

The polymorphonuclear neutrophil (PMN) regulates in vivo and in vitro immune responses. We report that the immunoenhancing properties of PMN culture supernatants from PMN recruited by the bacterium Actinomyces viscosus (AV) show its exclusive effects on the T cell lymphocyte population. A study of the effect of PMN supernatants on normal Balb/c splenocytes to T and B cell mitogens showed enhancing effects on T cell mitogens, but no effect on B cell mitogen responses when compared to a control. Adherent cells (macrophages) were not required for the enhancing effect, indicating that the supernatant worked directly on the T cell. Proliferation of El-4, a Lyt-1.2 positive lymphoma helper cell, was directly affected by these supernatants. Functionally, T cell-dependent plaque-forming cell responses to sheep red blood cells (SRBC) were enhanced. The polyclonal, T cell-independent plaque-forming cell response was unaffected when generated with LPS as assayed with Protein-A-SRBC. These results indicate that PMN supernatants from cells recruited by AV act on a helper T cell population to enhance both proliferation and differentiation in lymphocyte populations. These interactions provide insight into local inflammatory responses of PMN-lymphocyte infiltration with altered cell-mediated immunity.

Oral pathoses as diagnostic indicators in leukemia

A retrospective chart review of 500 leukemia patients was carried out to analyze the role of oral pathoses in the presentation of leukemia and to determine those factors which affect the frequency of oral involvement during the initial clinical phases of the disease. The data indicate that oral pathoses were frequent signs or symptoms in patients with undiagnosed acute leukemia but were less prevalent in patients with undiagnosed chronic leukemia. Neither age nor sex appeared to be a significant factor affecting oral involvement. Oral signs of thrombocytopenia were the most prevalent complaint of patients seeking diagnosis for their leukemia because of an oral problem, and they were also most frequently responsible for oral problems found at initial physical examination. Head and neck lymphadenopathy was also a frequent presenting sign or symptom. Dentists were responsible for initiating the diagnosis of leukemia in a significant number of patients with acute nonlymphoblastic leukemia.

Circulating immune complexes in patients following clinically curative resection of colorectal cancer

Sixty-nine patients have been followed prospectively after curative resection of Dukes-Kirklin B-2 or C colorectal cancer. Serial plasma samples were studied in selected patients to determine changes in circulating immune complex concentrations (CIC) following primary tumor resection, and to compare serial plasma CIC and carcinoembryonic antigen (CEA) levels. CIC was determined in an average of seven serial samples per patient by inhibition of antibody-dependent cell-mediated cytotoxicity (ADCC). CEA assays were performed by the Hanson Z-gel method. Two distinct patterns of serial CIC have emerged. In seven patients with no known tumor recurrences, serial CEA levels and CIC oscillated regularly and were inversely related. In seven of eight patients whose tumors recurred, both CEA and CIC rose together. In three patients with elevated plasma CEA levels due to inflammatory bowel disease, serial Ag-Ab complex concentrations did not vary, nor did separated Ag or Ab fractions inhibit ADCC. These data suggest that, in patients following curative resection of colorectal cancer, serial changes in circulating immune complexes may discriminate between transient CEA elevations which occur despite no known tumor recurrence and tumor recurrence which is beyond the capacity of adequate host antitumor defense.

Assessment of drug sensitivity of human leukaemic myeloblasts. I. Labelling human myeloblasts with 125IUdR for survival studies in mice

The compound (125)IUdR can be incorporated in a stable form into the DNA of cells. The isotope is released if labelled cells or their progeny die. Consequently the rate of (125)I excretion from mice can be used to follow the fate of labelled cells in vivo. Using these principles we show:(1) Sufficient label can be incorporated in vitro into both fresh and cryopreserved human leukaemic myeloblasts, in non-toxic concentrations, to allow their survival in mice to be estimated by whole-body counting;(2) The release of isotope from labelled cells is sufficiently slow to offer reasonable expectation that this technique can be used for assessing the sensitivity of myeloblasts to cytotoxic agents in vivo (an application described in the second paper in this series, Sonis, Falcão and MacLennon, 1977);(3) The rate of (125)Iexcretion from mice injected with myeloblasts from different donors varies. This probably reflects different rates of spontaneous death of injected myeloblasts;(4) Active rejection of myeloblasts starts within 48 h of their injection into mice;(5) Indirect evidence that phagocytic cells may be active agents in myeloblast destruction in mice;(6) Various methods of immunologically depriving mice were assessed to see if they would result in a useful increase in survival of injected human myeloblasts. We conclude that there is little advantage and some limitations in using mice thus deprived;(7) One of the agents used for immunological deprivation-silica powder-markedly decreased the rate of (125)I loss from mice injected with labelled killed myeloblasts. This experience emphasizes the importance of including the killed-cell control in this assay.

In vitro effects of isobutyl cyanocrylate on four types of bacteria

Isobutyl cyanoacrylate produced varying degrees of growth inhibition when applied to freshly plated Petri dishes of Staphylococcus aureus, Gaffkya, Neisseria catarrhalis, and a-Streptococcus. A biproduct or diffusible substance produced by the polymer was implicated as the cause. Destruction of growing colonies was observed only with a-Streptococcus after polymer application. The mechanism for this was not determined.