Circadian dynamics of tumor necrosis factor alpha (cachectin) lethality.

Recombinant human tumor necrosis factor-alpha (TNF-alpha) has demonstrable antitumor activity in transplantable murine tumor models and patients with cancer but is highly toxic to both animals and human beings. The narrow therapeutic index of TNF-alpha has limited its anticancer utility. Toxicity associated with many standard anticancer drugs is highly dependent upon the circadian timing of their administration. The effect of time of day of TNF-alpha administration on lethal toxicity was examined in 238 BALB/c female mice in two studies. Each mouse received a single intravenous injection of human TNF-alpha at one of six equispaced times within the first contiguous 24-h cycle. The probability of dying across all times of day of TNF-alpha treatment was not equal (p < 0.01) and varied up to ninefold. Significant time of day dependence of TNF-alpha toxicity was present over a full order of magnitude of TNF-alpha dose. The frequency of TNF-alpha-induced lethality was greatest and the time to death was most brief when TNF-alpha was administered just before awakening. The survival probability was highest when TNF-alpha was administered in the second half of the daily activity span corresponding roughly to late afternoon and evening hours for human beings. The optimization of TNF-alpha administration timing is a strategy that warrants further investigation for improving the toxic/therapeutic ratio of this important cytokine. From a more fundamental perspective, these data may be essential for achieving a fuller understanding of TNF-alpha in vivo biology.

Estrous influence on surgical cure of a mouse breast cancer.

We have studied the effect of estrous stage, as reflected by vaginal cellularity, at the time of surgical resection of an estrogen receptor-bearing mammary adenocarcinoma upon the metastatic potential of that tumor in the C3HeB/FeJ mouse. Presence of the tumor prolonged the length of the estrous cycle by approximately 25% and removal of the tumor returned the cycle to its usual duration. Neither estrous stage at tumor implant nor size of tumor at resection (within a small range) had significant independent effects upon differences observed in the incidence of subsequent pulmonary metastases. However, estrous stage at time of surgical removal of the tumor, as reflected by cell types in vaginal smear, markedly affected whether or not metastases ultimately appeared. Because the estrous cycle in mice, comparable to the human menstrual cycle, reflects high-amplitude, rhythmic changes in hormone concentrations, it may be that the hormonal status of a women at the time of tumor resection is an important determinant of whether or not that breast cancer ultimately metastasizes.

Circadian timing of cancer chemotherapy.

Animal studies have indicated that the time of administration of adriamycin and cisplatin, two widely used anticancer drugs, has a profound effect on their toxicity. This effect in cancer chemotherapy was studied in 31 patients with advanced ovarian cancer. Patients received at least eight monthly courses of adriamycin that were followed 12 hours later by cisplatin, with adriamycin randomly administered at either 6 a.m. or 6 p.m. The results show that in the group receiving adriamycin in the evening and cisplatin in the morning (i) twice as many patients required reductions in dosage and delays in treatment, (ii) four times as many treatments had to be delayed, (iii) drug dosages had to be modified downward three times as often, and (iv) even with more dose attenuation and treatment delays, treatment complications were still about two times more common as in the group receiving adriamycin in the morning and cisplatin in the evening. These findings show that the circadian stage at which anticancer drugs are given to patients should be carefully considered.

The respiratory sinus arrhythmia: a measure of cardiac age.

A method developed for quantifying respiratory sinus arrhythmia (RSA) during voluntary cardiorespiratory synchronization relies on computer-assisted rhythmometric cosinor analysis of instantaneous heart rate data. The RSA was present in all subjects tested, even those at advanced ages. The amplitude of the RSA falls approximately 10 percent per decade. An individual with a transplanted heart and one with severe diabetic neuropathy each had resting RSA values that were normal for their ages. The shape and amplitude of the RSA during voluntary cardiorespiratory synchronization may reflect the suppleness of the heart and its response to rhythmically changing intrathoracic pressure and the subsequent ebb-and-flow of venous return. Our technology allows objective quantitative assessment of the biologic age of the heart and also the effect of any drug, disease, or behavior that affects the RSA.

The effects of surgery on tumor growth: a century of investigations.

A few clinical investigations suggest that while primary breast cancer surgical removal favorably modifies the natural history for some patients, it may also hasten the metastatic development for others. The concepts underlying this disease paradigm, i.e. tumor homeostasis, tumor dormancy and surgery-driven enhancement of metastasis development, have a long history that is reviewed. The review reveals the context in which these concepts were conceived and structured to explain experimental data and shows that they are not so new and far fetched. The idea that surgical cancer resection has both beneficial and adverse effects upon cancer spread and growth that result from the modulation of tumor dormancy by the resection should be considered a potentially fruitful working hypothesis.

Dormancy and surgery-driven escape from dormancy help explain some clinical features of breast cancer.

To explain bimodal relapse patterns observed in breast cancer data, we have proposed that metastatic breast cancer growth commonly includes periods of temporary dormancy at both the single cell phase and the avascular micrometastasis phase. The half-lives of these states are 1 and 2 years respectively. We also suggested that surgery to remove the primary tumor often terminates dormancy resulting in accelerated relapses. These iatrogenic events are very common in that over half of all metastatic relapses progress in that manner. Assuming this is true, there should be ample and clear evidence in clinical data. We review here the breast cancer paradigm from early detection, through treatment and follow-up, and consider how dormancy and surgery-driven escape from dormancy would be observed. We examine mammography data, effectiveness of adjuvant chemotherapy, heterogeneity and aggressiveness, timing of surgery within the menstrual cycle and racial differences in outcome. Dormancy can be identified in these diverse data but most conspicuous is the sudden escape from dormancy following primary surgery. These quantitative findings provide linkage between experimental studies of tumor dormancy and clinical efforts to improve patient outcome.

Cisplatin-associated anemia: an erythropoietin deficiency syndrome.

Cisplatin-based therapy results in a cumulative anemia that is disproportionate to the effects on other blood cells. The severity of this treatment-induced anemia and the resultant transfusion requirement in cancer patients correlate with cisplatin-induced renal tubular dysfunction. Observed/expected serum erythropoietin (EPO) ratios decline with progressive cisplatin therapy and are proportionate to the degree of renal dysfunction. Recovery from anemia and of observed/expected serum EPO ratios in patients occurs after cessation of cisplatin therapy, along with restoration of renal tubular function. Creatinine clearance, however, remains permanently depressed. Cisplatin-treated rats develop progressive renal dysfunction and anemia that persists for many weeks, without effects on white blood cell counts. The anemia is also associated with a lack of expected EPO and reticulocyte response. With EPO administration, cisplatin-treated rats exhibit a greater reticulocyte response and hematocrit increment then non-cisplatin-treated rats given EPO, indicating minimal erythroid precursor cell damage from cisplatin. These results indicate the primary etiology of cisplatin-associated anemia is a transient, but persisting EPO deficiency state resulting from cisplatin-induced renal tubular damage, which can be prevented or treated by hormone (EPO) replacement.

Determination of the therapeutic index of floxuridine by its circadian infusion pattern.

To test if circadian timing of a drug is important for its toxicity and antitumor activity, we compared the circadian patterns observed with seven equal doses of floxuridine (FUDR) infused either at a variable rate or at a constant rate in female F344 rats. For the variable-rate infusion, the daily dose of FUDR was divided into four 6-hour portions of 68%, 15%, 2%, and 15% to achieve a quasisinusoidal pattern. Peak drug delivery occurred during one of six different times of day. At a dose level resulting in 50% overall mortality, lethal toxicity differed significantly, depending on the circadian stage of maximum drug delivery. Depending on the circadian stage of maximum drug flow, variable-rate infusions were more toxic than or as toxic as constant-rate infusion. FUDR lethality was lowest when constant-rate infusion was used or when variable-rate infusion peaked during the late activity-early rest span of the recipients. The circadian pattern of variable-rate infusion also determined the antitumor activity in tumor-bearing rats. At a therapeutic dose level and at identical dose intensity, the variable-rate-infusion pattern, with peak drug flow during the late activity-early rest span, resulted in significantly greater delay in tumor growth than was observed with either the constant-rate infusion or other variable-rate patterns. We conclude that the toxicity and antitumor activity of FUDR depend on the circadian timing of the infusion peak when the drug is given by variable-rate infusion. Since some of the circadian-shaped infusions studied are toxicologically and therapeutically inferior to constant-rate infusion, the circadian pattern and not the quasi-intermittency of circadian FUDR administration is primarily responsible for these pharmacodynamic differences.

Control of a murine plasmacytoma with doxorubicin-cisplatin: dependence on circadian stage of treatment.

In anticipation of the development of clinical chronotherapy and in order to pick clinical test times for doxorubicin and cisplatin trials, two large studies were performed on rats bearing a transplanted plasmacytoma. The circadian timing of each of two anticancer drugs given at precisely equal dose intensities was expected to improve therapeutic benefit over conventionally given (time-unqualified) treatment. In each chronotherapeutic study, maximal benefit and minimal toxic effects were found when cisplatin was administered in the middle to latter part of the daily activity (dark) span, while doxorubicin was administered near the end of the daily resting (light) span for these nocturnally active rodents living on a 12-hour-12-hour or 8-hour-16-hour light-dark schedule. This was true whether doxorubicin or cisplatin was given first and whether there was a lag of only a few hours or a few days between the administration of these two agents.

Natural killer cell activity: age, estrous- and circadian-stage dependence and inverse correlation with metastatic potential.

The timing within the estrous cycle of surgical removal of a transplanted murine mammary tumor profoundly influences the frequency of pulmonary metastases. We investigated the potential role of the immune response in this phenomenon by measuring splenic natural killer (NK) cell activity and interleukin-2 (IL-2) production in syngeneic tumor-free mice of two age groups at each of two circadian times and in each of four estrous stages. Estrous stage was determined by assessment of vaginal smear cellularity immediately prior to killing and spleen harvest. In a single-cell splenocyte preparation, NK cytotoxicity against a standard tumor cell target was assessed using a radiolabeled chromium release assay while IL-2 activity was determined in a bioassay utilizing the IL-2-dependent CTLL-2 cell line. Mice from the younger group were found to have eight-fold higher NK activity and 35% greater IL-2 production. After normalization of NK and IL-2 values for age, a highly statistically significant difference in NK activity was found among the four estrous and between the two circadian stages of sacrifice. NK activity was greater during the daily resting span across every estrous stage. IL-2 values were highest in diestrus and proestrus when sampled in the light span and in estrus-metestrus when sampled in the dark. The stages within the fertility cycle associated with lowest metastatic potential (proestrus/estrus) correspond precisely with those of highest splenocyte NK activity. These results indicate that an important component of the cellular immune response varies rhythmically both during the fertility and circadian cycles of the host. The rhythmic changes in NK activity may be in part responsible for the similarly rhythmic frequency of postsurgical metastatic dissemination.

Chronotherapy of ovarian cancer: effect on blood variables and serum cytokines. A case report.

A 7-year-old patient with Stage III-c ovarian cancer was subjected to 8 cycles, approximately four weeks apart, of chronobiologically-optimized treatments with combination of three anti-cancer agents: Four cycles at AM, Cytoxan and PM, cis-Platinum; four cycles at AM, Adriamycin and PM, cis-Platinum. A second look laporoscopy revealed clean intestines, no definite masses in the pelvis area although there was an apparent mass in the right upper pelvis and several slightly enlarged lymph nodes in the base of mesentery. Six cycles of Taxol were administered at about Noon. Seven months remission appeared evident as judged by no changes in monthly examinations, in blood work or in CA-125 marker levels which remained below 12 U/ml. During the eight month the CA-125 marker began to rise, 36 then to 52 U/ml. A second 6 cycle series of Taxol was initiated but the CA-125 marker continued to rise, 57, 65, 72, 86, and 87 U/ml level. The patient declined in spirit, in well-being and expired 2 weeks later, 31 months after the initial diagnosis of cancer. Blood hematology, chemistry, and cytokines variables were analyzed at about weekly intervals. Significant reductions in total WBC, neutrophiles and platelet levels were evident during the second week of all cycle treatments, while increases were noted in serum levels of IL-2, IL-6 and IL-10 following Cytoxan-cis-Platinum-Adriamycin, but not Taxol. After each infusion moderate and temporary increases in RBC levels were noted. The treatments impact on hematology, chemistry, cytokine variables and on the integrity of the patient, are presented and briefly discussed.

Circadian rhythmicity of polyamine urinary excretion.

Polyamines are small, highly charged, organic cations of possible regulatory importance in RNA-dependent protein synthesis, the production of which reflects cellular growth and division. The cytokinetics of normal cell populations is circadian rhythmic. This is reflected by a circadian rhythmicity undescribed previously in urinary monoacetylputrescine and the ratio of N1-acetylspermidine to N8-acetylspermidine in healthy individuals. Patients harboring advanced cancers sometimes excrete abnormal quantities of certain acetylated polyamines, and their urine samples may exhibit an abnormally high ratio of N1-acetylspermidine to N8-acetylspermidine. Changes in polyamine production and excretion associated with cancer may be best perceived by rhythmometric analysis of carefully timed samplings.

Circadian stage dependence of cis-diamminedichloroplatinum lethal toxicity in rats.

Renal physiology is circadian rhythmic. The major toxicity of cis-diamminedichloroplatinum (cisplatin) is irreversible renal damage. A single dose of cisplatin (11 mg/kg) was given to groups of standardized female Fischer 344 rats at one of six equispaced circadian stages. A statistically significant effect of time of injection upon tolerance was found by chi 2 analysis. Differences of 3- to 8-fold in survival rate of 50% mortality and a nearly 3-fold difference in long-term survival depended on circadian timing of cisplatin administration. Cisplatin timing resulting in optimal tolerance was similar from study to study. Additional 0.9% NaCl solution was administered with cisplatin in three experiments and resulted in an increase in overall mean survival time. It also resulted in an amplification of the survival rhythm without changing its timing. The increase in survival resulting from 0.9% NaCl solution loading, when compared to controls receiving cisplatin alone, was also highly time dependent. A 52% improvement in mean survival time was achieved in those animals receiving cisplatin and 0.9% NaCl solution at the most favorable circadian stage, as compared to a 20% improvement when this regimen was administered at an inopportune circadian stage. The safest time for cisplatin administration is near the midactivity span, shortly after the maximum of the circadian rhythm in rectal temperature.

Reduction of cis-diamminedichloroplatinum nephrotoxicity in rats by optimal circadian drug timing.

A prominent circadian rhythm in the nephrotoxicity of a therapeutic dose of cis-diamminedichloroplatinum (cisplatin) is demonstrated in female Fischer rats. Rats were randomized to receive two doses of either cisplatin or 0.9% NaCl solution 14 days apart at the times of either high or low values in their circadian rhythm of urinary volume. Toxicity was assessed by measuring changes in body weight and changes in the 24-hr means of urinary volume, blood urea nitrogen, and urinary beta-N-acetylglucosaminidase (NAG) activity. Toxicity was least in rats which received the drug near the circadian maximum of urinary volume. Conversely, rats which received the same dose of drug near the circadian minimum of urinary volume lost more weight and exhibited a 2-fold increase in the 24-hr mean of urinary volume, a 3-fold rise in the 24-hr mean of blood urea nitrogen, and a 5-fold increase in the 24-hr mean of urinary NAG activity. A positive correlation between urinary NAG at the time of cisplatin administration and the extent of cisplatin nephrotoxicity was demonstrated (p less than 0.02). A correlation also was found between tissue NAG concentration and tissue uptake of cisplatin (p less than 0.001). A marked circadian rhythm of NAG activity in proximal tubular cells may contribute to the prominent circadian rhythm in murine renal tolerance for cisplatin.

Circadian patterning of continuous floxuridine infusion reduces toxicity and allows higher dose intensity in patients with widespread cancer.

Continuous long-term 5-fluoro-2'-deoxyuridine (floxuridine; FUDR) infusion frequently causes severe and dose-limiting gastrointestinal toxicity when administered at a constant rate at commonly prescribed dose levels. In preclinical studies, a circadian infusion pattern peaking late in the daily activity phase was better tolerated and had superior antitumor activity than a constant infusion against a transplanted tumor. Based upon these data and upon other chronobiological cytokinetic and pharmacologic considerations, we compared a circadian patterned variable rate infusion with a maximal flow rate in the late afternoon/early evening and minimum flow rate during the early morning hours to a constant rate infusion in 54 patients with widespread cancer. All FUDR infusions were administered using an implanted drug pump. In a pilot crossover study and a second randomized trial, patients with metastatic malignancies treated with equal dose intensities experienced less frequent and less severe diarrhea, nausea, and vomiting following variable rate infusion. In a third study, the dose intensity of variable rate infusion was escalated stepwise to determine the maximum-tolerated dose. Patients receiving time-modified FUDR infusion tolerated an average of 1.45-fold more drug per unit time while evincing minimal toxicity. FUDR infusion was found to have activity against progressive metastatic renal cell cancer (RCC). Increased dose intensity achieved by optimal circadian shaping may improve the therapeutic index of infusional FUDR and may help control malignancies that are refractory to conventional chemotherapy.

Circadian cancer therapy.

PURPOSE AND DESIGN: To review briefly the growing body of published data about circadian variation in cytotoxic drug metabolism and tissue sensitivity to chemotherapeutic agents. The suggestion that toxicity may be reduced and anticancer efficacy improved by administering antineoplastic agents at carefully selected times of the day was assessed. RESULTS AND CONCLUSION: The medical literature describing molecular, cellular, and organismic time-keeping mechanisms, as well as circadian rhythms, in cytokinetic, pharmacokinetic, and pharmacodynamic parameters relevant to cancer chemotherapy, which support the predictable rhythmic relationship between dose and effect that occurs during each day, were reviewed. Advantages for optimal circadian scheduling have been demonstrated for diminishing side effects and increasing maximal safe dose-intensity of drugs of diverse class. The use of the predictable circadian relationship of dose and response provides another increment of progress in the treatment of cancer patients.

Circadian-shaped infusions of floxuridine for progressive metastatic renal cell carcinoma.

Sixty-eight unselected patients with progressive metastatic renal cell carcinoma (RCC) were treated between March 1985 and November 1988 with continuous infusion floxuridine (FUDR). Thirty-seven percent of these patients had previously received and failed systemic treatment. Using implantable pumps for automatic drug delivery, FUDR was continuously infused for 14 days at monthly intervals. The starting dose was 0.15 mg/kg/d (intravenous [IV]; n = 61) or 0.25 mg/kg/d (intraarterial [IA]; n = 7); IV doses were increased or decreased in increments of 0.025 mg/kg/d as permitted by toxicity. Diarrhea (with or without mild abdominal cramping) and nausea/vomiting limited the FUDR IV infusion, and hepatic function abnormalities limited FUDR IA infusion. The use of a circadian-modified infusion schedule permitted high FUDR doses to be safely given as compared with a constant rate infusion schedule. Of 63 patients assessable for response, 56 received systemic FUDR infusion. Four complete responses (CRs; 7.1%); and seven partial responses (PRs; 12.5%) were observed (objective response rate, CR plus PR, 19.6 +/- 5.1% [95% confidence limits] ). The median objective response duration was 10.8 months (range, 1 to 18 months; mean, 9.4 +/- 1.6). Four additional patients had minor tumor responses (MRs; 7.1%). In a subgroup of seven assessable patients receiving hepatic arterial FUDR, we observed one CR and three PRs (57.2 +/- 42.8%). Overall, objective response (CR plus PR) was seen in a quarter of assessable patients treated, 15 of 63, while only 15 of the 63 assessable patients (25.4%) have had objective tumor progression. The median follow-up time for all 68 patients was 28 months (range, 1 to 42), and their median survival duration is 15 months (range, 3 to 37 months). Continuous infusion FUDR is an effective outpatient treatment for progressive metastatic RCC, producing durable tumor response and causing little toxicity.

Lack of antiemetic effect of high-dose metoclopramide.

Sixteen of 26 patients given 51 courses of treatment of the doxorubicin and cisplatin combination with no antiemetic therapy suffered the same number of vomiting episodes and had the same duration of vomiting as did the remaining ten patients given 20 cycles of this chemotherapy plus the standard high-dose metoclopramide regimen. This antiemetic regimen caused significant side effects in one fifth of the patients receiving it.

High-dose intensity systemic therapy of metastatic bladder cancer.

Forty-three consecutively diagnosed patients with widely metastatic transitional cell carcinoma of the bladder (TCCB) were treated with a high-dose intensity, chronobiologically timed combination of doxorubicin and cisplatin, followed by Cytoxan (Mead Johnson Pharmaceuticals, Evansville, IN), 5-fluorouracil (5-FU), and cisplatin maintenance for up to 2 years. Fifty-seven percent of the 35 evaluable patients with widespread metastatic cancer responded objectively. Twenty-three percent had complete disappearance of all cancer. Median survival from first treatment for complete responders (CRs) was more than 2 years, and 1 year for partial responders (PRs). Three of the CRs were alive without evidence of cancer more than 2 years after stopping all therapy. High-dose intensity combination chemotherapy can induce durable CRs of widespread bladder cancer.

Subcutaneous heparin-induced thrombocytopenia.

Two patients developed severe and symptomatic thrombocytopenia which was clearly related to the every-12-hour subcutaneous administration of heparin sodium. One patient died of hemorrhage while the other patient's platelet count normalized after withdrawal of the therapy. The literature reveals 27 cases of significant thrombocytopenia associated with intravenous heparin administration. In light of the increasing use of low-dose subcutaneous heparin therapy it is important to recognize that this side effect may occur. Periodic platelet counts are recommended for these patients.