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.

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.

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 function in patients with advanced non-small-cell lung cancer.

This study aimed to evaluate whether patients with advanced non-small-cell lung cancer experience disrupted rest-activity daily rhythms, poor sleep quality, weakness, and maintain attributes that are linked to circadian function such as fatigue. This report describes the rest-activity patterns of 33 non-small-cell lung cancer patients who participated in a randomised clinical trial evaluating the benefits of melatonin. Data are reported on circadian function, health-related quality of life (QoL), subjective sleep quality, and anxiety/depression levels prior to randomisation and treatment. Actigraphy data, an objective measure of circadian function, demonstrated that patients' rest-activity circadian function differs significantly from control subjects. Our patients reported poor sleep quality and high levels of fatigue. Ferrans and Powers QoL Index instrument found a high level of dissatisfaction with health-related QoL. Data from the European Organization for Research and Treatment for Cancer reported poor capacity to fulfil the activities of daily living. Patients studied in the hospital during or near chemotherapy had significantly more abnormal circadian function than those studied in the ambulatory setting. Our data indicate that measurement of circadian sleep/activity dynamics should be accomplished in the outpatient/home setting for a minimum of 4-7 circadian cycles to assure that they are most representative of the patients' true condition. We conclude that the daily sleep/activity patterns of patients with advanced lung cancer are disturbed. These are accompanied by marked disruption of QoL and function. These data argue for investigating how much of this poor functioning and QoL are actually caused by this circadian disruption, and, whether behavioural, light-based, and or pharmacologic strategies to correct the circadian/sleep activity patterns can improve function and QoL.

Breast cancer recurrence dynamics following adjuvant CMF is consistent with tumor dormancy and mastectomy-driven acceleration of the metastatic process.

PURPOSE: The aim of this study was to better understand human breast cancer biology by studying how the timing of metastasis following primary resection is affected by adjuvant CMF (cyclophoshamide, methotrexate, 5-fluorouracil) chemotherapy. PATIENTS AND METHODS: Discrete hazards of recurrence and recurrence risk reductions for treated patients relative to controls were analyzed for all patients enrolled in two separate randomized clinical trials [study 1 (386 women): no further treatment versus 12 cycles of CMF; study 2 (459 women): six versus 12 cycles of CMF] and a historical group (396 women: surgery alone) of axillary node-positive patients undergoing mastectomy. RESULTS: (i) Nearly all CMF benefit occurs during the first 4 years following resection/chemotherapy. (ii) The CMF recurrence rate reduction is largely restricted to two specific spans. These temporally separate recurrence clusters occur during the first and third year of follow-up, while the second-year recurrences are weakly affected. (iii) Prolonging adjuvant treatment from 6 to 12 months partially alters this recurrence timing, without appreciably affecting the overall recurrence rate. (iv) These effects upon the dynamics of post-resection occurrence are menopausal status-independent. CONCLUSIONS: At least two different therapeutically vulnerable proliferative events, resulting in clinical appearance of two metastasis temporally distinct clusters of post-resection cancer recurrence, apparently occur during the administration of adjuvant chemotherapy. Metastases that transpire outside of these temporal windows are refractory to adjuvant therapy. The dynamics of both post-treatment recurrence risk and CMF effectiveness are similar for both pre- and postmenopausal women, suggesting that post-resection mechanisms by which chemotherapy prevents metastases are similar, but of different magnitude in pre- and postmenopausal women. These findings are consistent with a metastasis model that includes tumor dormancy in specific micrometastatic phases (single cells and avascular foci) and with the acceleration of the metastatic process by the surgical resection of the primary breast cancer.

Tumor chronobiology.

Traditionally, drug delivery has meant getting a simple chemical absorbed predictably from the gut or from the site of injection. A second-generation drug delivery goal has been the perfection of continuous constant rate (zero-order) delivery of simple xenobiotic molecules or common hormones. Living organisms are not 'zero-order' in their requirement for or response to drugs. They are predictable resonating dynamic systems, which require different amounts of drug at predictably different times within the circadian cycle in order to maximize desired and minimize undesired drug effects.

Circadian expression of clock genes in human oral mucosa and skin: association with specific cell-cycle phases.

We studied the relative RNA expression of clock genes throughout one 24-hour period in biopsies obtained from the oral mucosa and skin from eight healthy diurnally active male study participants. We found that the human clock genes hClock, hTim, hPer1, hCry1, and hBmal1 are expressed in oral mucosa and skin, with a circadian profile consistent with that found in the suprachiasmatic nuclei and the peripheral tissues of rodents. hPer1, hCry1, and hBmal1 have a rhythmic expression, peaking early in the morning, in late afternoon, and at night, respectively, whereas hClock and hTim are not rhythmic. This is the first human study to show a circadian profile of expression for all five clock genes as documented in rodents, suggesting their functional importance in man. In concurrent oral mucosa biopsies, thymidylate synthase enzyme activity, a marker for DNA synthesis, had a circadian variation with peak activity in early afternoon, coinciding with the timing of S phase in our previous study on cell-cycle timing in human oral mucosa. The major peak in hPer1 expression occurs at the same time of day as the peak in G(1) phase in oral mucosa, suggesting a possible link between the circadian clock and the mammalian cell cycle.

Premenopausal status accelerates relapse in node positive breast cancer: hypothesis links angiogenesis, screening controversy.

Much attention has been given to determining the benefit of mammographic screening to reduce breast cancer mortality. Eight randomized clinical trials have been conducted in four countries: the US, Canada, Scotland and Sweden. Trials report an early and stable 30% reduction in breast cancer mortality for women aged 50-59. For women under 50, unexpectedly, the early years of screening produce a disadvantage to the screened population. Only in later years does an advantage appear. To help understand this, we studied relapse patterns using a breast cancer database of 1,173 pre- and postmenopausal, node negative and positive patients treated with surgery only and having 16-20 years of follow-up. This approach is relevant since at least five of the eight screening trials began before the widespread use of adjuvant chemotherapy in the 1980s. Surgical cure rates were independent of menopausal status. However, a major difference in early relapse rate was found. In premenopausal and node positive patients, 27% of all distant relapses occurred within the first 10 months following resection. This is twice the early relapse frequency of any other clinical group. Using computer simulation, we interpret that these early relapses probably result from a disadvantage induced at surgery. A disinhibition or surgery/wounding induced angiogenic surge might be responsible. Disinhibition is known to occur in animal models such as Lewis lung where lung metastases are avascular and dormant until the primary is removed. Sudden outgrowth of tumor after wounding has been observed for a century. According to the simulation, in breast cancer this induction apparently accelerates inevitable relapses by a median of two years. This is offset in later years with a balancing reduction in relapses. These data suggest that the angiogenic switch may be upregulated more frequently among premenopausal women, perhaps depending upon the sex hormones. The acceleration would cause 0.11 deaths per 1,000 screened aged 40-49 subjects in years 2-3, a value comparable to the early year excess mortality in trials of a significant 0.15 deaths per 1,000 subjects. Equal screening advantage is predicted for node negative (but not node positive) pre- and postmenopausal patients. The acceleration of relapse after surgery may explain the paradoxical effect of mammographic screening for women under 50.

Cisplatin-incorporated polymeric micelles eliminate nephrotoxicity, while maintaining antitumor activity.

cis-Diamminedichloroplatinum (II) (cisplatin, CDDP), a potent anticancer agent, was bound to the aspartic acid residues of poly(ethylene glycol)-poly(aspartic acid) (PEG-P(ASP)) block copolymer by ligand substitution reaction at the platinum atom of CDDP. The polymeric drug thus obtained was observed to form a micelle structure in aqueous medium, showing excellent water solubility. In the present study, in vitro and in vivo antitumor activity against several human tumor cell lines, toxicity and pharmacokinetic characteristics in rodents of CDDP-incorporated polymeric micelles (CDDP / m) were evaluated in comparison with those of CDDP. In vitro, CDDP / m exhibited 10 - 17% of the cytotoxicity of CDDP against human tumor cell lines. CDDP / m given by intravenous (i.v.) injection yielded higher and more sustained serum levels than CDDP. In vivo CDDP / m treatment resulted in higher and more sustained levels in tumor tissue than CDDP, and showed similar antitumor activity to CDDP against MKN 45 human gastric cancer xenograft. CDDP / m treatment caused much less renal damage than CDDP. These results indicate that CDDP / m treatment can reduce CDDP-induced nephrotoxicity without compromising the anticancer cytotoxicity of CDDP.

Circadian organization of thymidylate synthase activity in normal tissues: a possible basis for 5-fluorouracil chronotherapeutic advantage.

Fluoropyrimidines induce cytotoxicity, in part, by inhibiting the proliferation-coordinated enzyme thymidylate synthase (TS), which is essential for DNA synthesis. Tumor TS levels are clinically predictive of post-surgical tumor recurrence and of response to fluoropyrimidine chemotherapy. Fluoropyrimidine drug toxicity and efficacy each vary reproducibly in humans and animals, depending upon their circadian timing. In vivo, normal tissues and some tumor tissues exhibit circadian coordination of cellular proliferation. We therefore asked whether TS activity is coordinated rhythmically throughout the day in the normal proliferative tissues most damaged by fluoropyrimidine drugs. To assess tissue and time of day TS activity differences, we harvested normal tissues from female mice living on a 12:12 hr light:dark schedule at each of 6 different equispaced times throughout a 24 hr cycle and measured TS catalytic activity. We observed up to 10-fold differences in vivo in TS activity among different normal tissue types, roughly paralleling their proliferative state and relative fluoropyrimidine sensitivity. In normal tissues most damaged by fluoropyrimidines (bone marrow, small intestinal mucosa and oral mucosa/tongue), TS activity varies up to 2-fold throughout each day. In bone marrow, the circadian pattern of TS activity parallels the circadian rhythm in proliferation in this tissue. This circadian organization of TS, one of the primary fluoropyrimidine targets in normal tissues, probably contributes in vivo to the time of day differences in the toxic-therapeutic ratio of circadian-timed fluoropyrimidine drug therapy.

Investigation of the comparative toxicity of 5-FU bolus versus 5-FU continuous infusion circadian chemotherapy with concurrent radiation therapy in locally advanced rectal cancer.

PURPOSE: To compare the relative toxicities of bolus versus infusional 5-FU chemotherapy administrated concurrently during external beam irradiation in patients with locally advanced rectal cancer following surgical extirpation. METHODS: A total of 26 eligible patients were retrospectively identified as having been treated for rectal adenocarcinoma at the Stratton VAMC between 1989 and 1997. A comparative analysis of treatment dose intensities, treatment delays and toxicities in these patients was performed. RESULTS: Significantly less WBC toxicity was observed in the patients receiving infusional 5-FU chemotherapy. The other toxicities, with the exception of skin toxicity, were generally less frequent in the 5-FU infusional group. When the toxicities were corrected for 5-FU dose intensity, to yield toxicity per mg of 5-FU, statistically significant differences were found for hematological toxicity (WBC and platelets), and for gastrointestinal toxicity (frequency and severity of diarrhea and weight loss). The majority of patients receiving infusional 5-FU therapy were treated using a circadian pattern of treatment peaking around the time of the radiation therapy. Patients receiving infusional 5-FU were able to tolerate over twice the dose intensity as those receiving bolus administration. Local recurrence rate in all patients was 3.8% comparing favorably to other reported studies. Distant recurrence frequency was also acceptable at 34.6% for the group. CONCLUSION: Infusional 5-FU chemotherapy compared with bolus therapy during pelvic radiation minimizes toxicity to the patient while maximizing the dose of 5-FU that can be delivered. As infusional 5-FU therapy during radiation has previously been shown to increase disease free duration and survival, infusional 5-FU should be considered as an acceptable standard of care to prevent local recurrence of rectal adenocarcinoma following its resection. Shaping this infusional 5-FU chemotherapy within the day so that most of the daily dose is delivered around the time of the radiation therapy may further modify the toxic therapeutic ratio of combined modality therapy.

The temporal organization of life: the impact of multi-frequency non-linear biologic time structure upon the host-cancer balance.

The current scientific paradigm, based upon an erroneous assumption of linear biologic reality and simple cause and effect relationships, has outlived its usefulness. In order to begin to turn the voluminous data the reductive process provides us with daily into meaningful understanding of life, it is essential to integrate these data within a complex, multi-frequency temporo-spatial framework. This rhythmic chronobiology more accurately depicts the life process, as well as its evolutionary and ongoing vital interaction with the pulsating cosmic resonance structure. Examples of the kinds of thinking and experiments necessary to exploit this new paradigm are provided.

Fertility maintenance and 5-fluorouracil timing within the mammalian fertility cycle.

The mammalian fertility cycle is responsible for tight coordination of molecular, biochemical and cellular events. We have investigated whether timing of 5-fluorouracil (5-FU) chemotherapy within this cycle affects its reproductive toxicology. When this very short half-life, largely S-phase active cytotoxic antimetabolite is administered during the estrous phase (immediate postovulatory) of the fertility cycle, female mice suffer greater subsequent loss of fertility (decreased successful pregnancy rate) than those mice receiving 5-FU during the metestrous, diestrous, or proestrous stages. Pups subsequently born to mothers given 5-FU during the estrous and metestrous stages are of lower weight compared with those born to mothers treated with 5-FU during diestrus or proestrus. Acute lethality is similarly affected by the fertility cycle timing of 5-FU administration. Treatment during estrus is associated with the greatest overall lethal toxicity. This finding indicates that the 5-FU susceptibility of nonreproductive tissues, the integrity of which is essential for survival, may also be coordinated by the mammalian fertility cycle. It is concluded that optimizing the fertility cycle timing of 5-FU (e.g., during the periovulatory, proestrous stage) diminishes the frequency and severity of long-term reproductive damage.

Circadian coordination of cancer growth and metastatic spread.

To understand whether mammalian circadian time structure measurably affects the host-cancer balance, we studied tumor-take frequency after s.c. tumor cell inoculation and the number of pulmonary tumor nodules after i.v. tumor cell injections at each of 6 equispaced times of day. We employed 2 genetically distinct mouse strains and 2 different tumor model systems, a methylcholanthrene A-induced fibrosarcoma of C(3)HeJ mice and 2 B(16) melanoma cell lines of vastly different metastatic efficiency in C57 Black/6 mice. Fibrosarcoma cells were injected s.c. in 1 of 8 different doses, at 1 of 8 permutated anatomic sites and at 1 of 6 equispaced circadian times, in 96 female C(3)HeJ mice maintained under a synchronizing schedule of 12 hr light alternating with 12 hr dark. Regardless of tumor cell dose and inoculum location, tumor-take frequency depended strongly upon the circadian stage of tumor cell inoculation. Injections of between 2,000 and 50,000 live tumor cells inoculated near the daily sleep/wake interface resulted in the lowest incidence of tumor take compared with inoculation at other times of day. In the experimental i.v. B(16) melanoma metastatic model (N = 110), the capacity of both high and low metastatic potential clones to successfully metastasize to lung depended, to a large extent, upon when in the day each of these clones was injected. Similar to the fibrosarcoma data, the daily sleep/wake boundary was the time of day associated with the greatest resistance to metastatic spread.

Distinct circadian time structures characterize myeloid and erythroid progenitor and multipotential cell clonogenicity as well as marrow precursor proliferation dynamics.

Circadian differences in the susceptibility of the marrow to the effects of radiation, myelotoxic drugs, and growth factors suggest that hematopoietic processes vary significant throughout each day. One mechanism possibly responsible for the differing degrees of marrow damage sustained from a fixed dose of a cytotoxic agent at different times of day is the circadian organization of cell cycle events. Previous circadian rhythm-oriented studies of proliferation using unfractionated marrow have reported seemingly contradictory peak and nadir times of day. Marrow represents a heterogeneous population of stem cells and various hematopoietic progenitors whose proliferation and differentiation are controlled by both common and unique factors. Therefore, we examined lineage-specific circadian marrow proliferative dynamics for evidence of parasynchronous circadian DNA synthesis. Cell cycle phase was determined using flow cytometry with both propidium iodide staining and 5-bromo-2'-deoxyuridine (BrdU) incorporation concurrently with cell culture-based determinations of lineage-specific progenitor numbers in the same marrow samples. Although no clear circadian (24-hour) rhythm characterized unfractionated marrow DNA synthesis, both erythroid- and myeloid-enriched subpopulations demonstrated distinct circadian patterns with respect to the percentage of cells incorporating BrdU, with up to 50% differences throughout each day. Interestingly, these circadian rhythms in erythroid and myeloid progenitor cell DNA synthesis are entirely different from one another. The lineage-specific circadian patterns in the fraction of cells undergoing DNA synthesis are, in part, paralleled by up to eightfold larger circadian differences in erythroid and myeloid colony numbers. Multipotential colony numbers likewise vary throughout the day, with a unique pattern of their own. The predominant period length of daily rhythms in colony numbers and their amplitudes differ as a function of the stage of progenitor commitment. Multipotent and early progenitor colony numbers each exhibit 24-hour rhythms, with three- to fivefold daily peak-trough differences, whereas later progenitor colony numbers exhibit two peaks per day (12-hour rhythms) with twofold peak-trough differences throughout each day. In vivo erythropoietin (Epo) administration enhances daily rhythms in erythroid colony numbers by increasing their amplitudes while leaving their circadian shapes virtually unchanged. The increment in erythroid colony numbers after Epo administration varies up to 16-fold with the time of day of treatment. In summary, we have defined distinctly different lineage-dependent circadian patterns of marrow progenitor numbers and proliferating cells. We can infer from these data that the circadian timing of administration of physical, chemical, or biologic agents, whose bioactivity toward marrow precursors depends on the cell cycle phase of its presentation, can be expected to affect this activity predictably and significantly. These results may have practical applications in improving stem and progenitor cell yields by optimal circadian timing of growth factor administration and harvest.

Menstrual timing of breast cancer surgery.

PURPOSE AND DESIGN: This is a critical review of the growing body of data, 32 retrospective studies of the outcomes of 9,665 women published since 1989, relevant to the possibility that the timing of primary breast cancer resection within the menstrual cycle impacts breast cancer recurrence and/or spread and patient survival. This article evaluates and contrasts the adequacy of information and data analysis presented in each publication. The overall purpose of this exercise is to rigorously determine the relative strength of the hypothesis that the menstrual cycle timing of operation impacts outcome and, thereby, to determine whether or not a specific change in the practice of breast surgical oncology can be recommended. RESULTS: The single most completely reported and thoroughly analyzed series, involving 1,175 young women, indicates that surgical resection timing is likely to be relevant to outcome. Seven additional high-quality studies involving 2,864 women have been most completely reported. While two of these eight find no impact, six (75%) of these studies find that breast cancer outcome is affected by operative timing. Nine of the remaining 24 less-complete studies report a statistically significant effect of operative timing. Among these 15 studies of the fates of more than 5,000 women, the opportune menstrual cycle phase almost invariably includes the putative luteal phase. A large number of retrospective studies of widely varying quality find no outcome difference as a function of resection timing. The adequacy of design of each of four ongoing prospective studies is found lacking. CONCLUSIONS: Although it is likely that the menstrual cycle phase of operation is relevant to outcome, the nature of the available data cannot allow a clear recommendation of precisely when to operate. It is, therefore, concluded that current retrospective data are inadequate to recommend an immediate change in practice. Prospective studies of this potentially important question are essential. The prospective trials initiated to date will not be able to definitively answer this question because of inadequate chronobiological design. The minimal requirements for adequate prospective study are delineated.