Ten-year results of a German Hodgkin Study Group randomized trial of standard and increased dose BEACOPP chemotherapy for advanced Hodgkin lymphoma (HD9)

LBA8015

Background: The HD9 trial was designed to compare standard and dose escalated versions of a novel chemotherapy BEACOPP in advanced Hodgkin lymphoma. The previous analysis in 2004 showed improved tumor control and overall survival due to dose escalation. The present 10 year analysis in March 2007 aimed to update and confirm these results and to monitor late effects. Methods: Patients aged 16–65 years with untreated Hodgkin lymphoma stage IIB/IIIA and risk factors or stage IIIB/IV were randomized to (A) 4 double cycles COPP/ABVD, (B) 8 cycles standard-dose BEACOPP or (C) 8 cycles increased-dose BEACOPP (doxorubicin, cyclophosphamide and etoposide at 140%, 192% and 200% of standard doses, respectively), each followed by irradiation of initial bulky and residual disease. Accrual of at least 900 patients was planned so as to detect a 9–10% improvement in the primary endpoint, freedom from treatment failure (FFTF), with a power of 80% (alpha=5%). Results: 1196 of 1201 eligible, randomized patients were evaluable (261, 469 and 466 in arms A, B and C, respectively). Median follow-up times were 122, 111 and 107 months in arms A, B and C respectively (29–32 months longer than in 2004). Corresponding 10-year FFTF rates were 64%, 70% and 82% respectively (p<0.0001). FFTF was significantly better in the increased-dose arm than in the standard-dose arm (p<0.0001). 10-year overall survival rates were 75%, 80% and 86% respectively (p=0.0005). Overall survival was also significantly better in the increased-dose arm than in the standard-dose arm (p=0.0053). Death due to HL was 11.5%, 8.1% and 2.8% in arms A, B and C respectively. 74 second malignancies were documented: 1, 7 and 14 acute myeloid leukemias (AML); 7, 8 and 5 non-Hodgkin lymphomas; 7, 16 and 9 solid tumors/others in arms A, B and C respectively. The corresponding overall secondary malignancy rates were 6.7% , 8.9% and 6.8%. Conclusions: Even after 10 years, dose escalation of BEACOPP chemotherapy results in a stabilized significant improvement in long-term FFTF and OS rates. The risk of secondary AML, although increased in this study after increased-dose BEACOPP, amounts to 0.9% in the succeeding study with increased BEACOPP with 1502 patients and 4 years median follow-up.

No significant financial relationships to disclose.

A phase I study of clofarabine in combination with cyclophosphamide and etoposide: A new regimen in pediatric patients with refractory or relapsed acute leukemia

9529

Background: Clofarabine is a promising new agent in the treatment of childhood leukemia as evidenced by single agent activity in previous phase I and II studies. We conducted a pilot phase I study of clofarabine used in combination with cyclophosphamide and etoposide to determine the maximum tolerated dose (MTD) and dose limiting toxicities (DLT). Methods: Patients between 1 and 21 years old with relapsed or refractory acute lymphoblastic leukemia (ALL) and acute myelogenous leukemia (AML) were enrolled. A standard 3+3 design was followed to determine the safe dose when used in combination. All drugs were administered by IV infusion daily for 5 consecutive days in induction and 4 days in consolidation. Patients received up to 2 induction cycles depending on the response, followed by consolidation cycles (maximum of 8 total cycles). The initial doses (cohort 1) were as follows: clofarabine: 20 mg/m2/day, etoposide 75 mg/m2/day and cyclophosphamide 340 mg/m2/day. Once etoposide and cyclophosphamide were escalated to their target dose (100 mg/m2/day and 440 mg/m2/day respectively in cohort 3), clofarabine was then increased to 30 mg/m2/day in cohorts 4 and would be increased to 40 mg/m2/day in cohort 5. Results: Thirteen patients (10 ALL; 3 AML) were enrolled in the first 4 dose cohorts to this date. The median number of prior regimens was 2. Response data (based on investigator assessment) are available for the first 8 patients: 6 patients (including 1 patient with AML) achieved either complete remission (CR) or complete remission without platelet recovery (CRp), for an overall response rate of 75%. Four patients proceeded to HSCT. One patient in cohort 4 experienced a DLT which resolved (grade 3 elevation of lipase) and possible veno-occlusive disease leading to cohort expansion. Common toxicities noted include febrile neutropenia and fever. Conclusions: The phase I study is ongoing until determination of MTD for this combination but these early results indicate that this combination shows significant activity in children with refractory or relapsed acute leukemias and is well-tolerated.

No significant financial relationships to disclose.

The pathological role of Bax in cisplatin nephrotoxicity

Nephrotoxicity induced by cisplatin involves tubular cell necrosis and apoptosis; the latter of which may be initiated by multiple mechanisms including activation of the intrinsic mitochondrial pathway. In cultured tubular epithelial cells, cisplatin can activate the proapoptotic protein Bax resulting in cytochrome c release, caspase activation, and apoptosis. Definitive evidence for the involvement of Bax in cisplatin nephrotoxicity in vivo, however, is lacking. We analyzed Bax regulation during cisplatin nephrotoxicity in wild-type mice and determined the pathological role of Bax using mice in which this gene was knocked out. In wild-type mice, cisplatin induced Bax in renal tubular cells which became active, accumulated in the mitochondria, and was accompanied by acute kidney injury. Compared with the wild-type mice renal function, as measured by blood urea nitrogen and serum creatinine, was partially but significantly preserved in Bax knockout mice. The number of apoptotic cells was decreased as was general tissue damage. Additionally, cisplatin-induced cytochrome c release was attenuated in the Bax-deficient mice. This significant decrease in apoptosis and in cytochrome c release was also mirrored in primary cultures of proximal tubular cells prepared from Bax knockout animals. Collectively, our results provide compelling evidence for a role of Bax and its related apoptotic pathway in cisplatin nephrotoxicity.

Second malignancy risk associated with treatment of Hodgkin's lymphoma: meta-analysis of the randomised trials

BACKGROUND

Despite several investigations, second malignancy risks (SMR) following radiotherapy alone (RT), chemotherapy alone (CT) and combined chemoradiotherapy (CRT) for Hodgkin's lymphoma (HL) remain controversial.

PATIENTS AND METHODS

We sought individual patient data from randomised trials comparing RT versus CRT, CT versus CRT, RT versus CT or involved-field (IF) versus extended-field (EF) RT for untreated HL. Overall SMR (including effects of salvage treatment) were compared using Peto's method.

RESULTS

Data for between 53% and 69% of patients were obtained for the four comparisons. (i) RT versus CRT (15 trials, 3343 patients): SMR were lower with CRT than with RT as initial treatment (odds ratio (OR) = 0.78, 95% confidence interval (CI) = 0.62-0.98 and P = 0.03). (ii) CT versus CRT (16 trials, 2861 patients): SMR were marginally higher with CRT than with CT as initial treatment (OR = 1.38, CI 1.00-1.89 and P = 0.05). (iii) IF-RT versus EF-RT (19 trials, 3221 patients): no significant difference in SMR (P = 0.28) although more breast cancers occurred with EF-RT (P = 0.04 and OR = 3.25).

CONCLUSIONS

Administration of CT in addition to RT as initial therapy for HL decreases overall SMR by reducing relapse and need for salvage therapy. Administration of RT additional to CT marginally increases overall SMR in advanced stages. Breast cancer risk (but not SMR in general) was substantially higher after EF-RT. Caution is needed in applying these findings to current therapies.

Pharmacokinetics and pharmacodynamics of asparaginases in antibody-negative pediatric patients with higher risk acute lymphoblastic leukemia (ALL): A report from CCG-1961

9027

Background: Asparaginase (ASNase) induces apoptosis in ALL lymphoblasts by depleting cells of extracellular asparagine (ASN) and possibly glutamine (GLN). On CCG-1961 [Seibel NL et al. Blood 2003; 102(11): 224a (abstract #787)], all patients (pts) received 9 doses of native E.coli-ASNase in induction (IND). Pts with rapid early response (marrow blasts < 25% on Day 7, RER) were randomized to standard intensity therapy and received native ASNase thereafter or to stronger intensity therapy and received PEG-ASNase post induction. All pts with slow early response (marrow blasts ≥ 25% on Day 7, SER) received PEG-ASNase after induction. Pts with clinical allergy to E.coli-ASNase were switched to Erwinase. Methods: Anti-ASNase Antibody (Ab) titers were assayed at the end of IND, prior to Delayed Intensification #1 and prior to starting Maintenance. Amino acid levels were measured in 430 sera from 187 patients with measurable ASNase activity. Results: Population pharmacokinetics (PK) and pharmacodynamics (PD) of the ASNase formulations demonstrated half-lives of native ASNase (6000 IU/m2): 30 hours, PEG-ASNase (2500 IU/m2): 156 hours, and Erwinase (6000 IU/m2): 18 hours. Subsequent exposures to either formulation resulted in increased activity with moderate prolongation of the elimination half-lives. One-hundred forty-two sera from 70 patients with ASNase activity between 0.03 and 1.11 IU/ml, had a mean ± SDEV ASNase activity, ASN levels, and GLN levels of 0.21 ± 0.23 IU/ml, 14.6 ± 17.7 μM, and 300.4 ± 233.8 μM, respectively; with median values of 0.11 IU/ml (range: 0.03–1.114 IU/ml), 4.7 μM (range: 0.38 - 81.34 μΜ), and 270.2 μM (range: 5.3 - 1189.1 μM), respectively. TTEST analyses linked higher ASNase activity with lower ASN levels and greater % ASN deamination. Higher ASNase activity did not assure greater GLN depletion. Conclusions: A sigmoid relationship between ASNase levels and % ASN deamination showed that activity of 0.41 ± 0.24 IU/ml (mean ± SDEV) provided 93% ± 13% ASN deamination. Therefore, >90% ASN deamination required ASNase >0.4 IU/ml. Kaplan-Meier analyses are pending.

[Table: see text]

Dynamic bond constraints in protein Langevin dynamics

Bond constraint algorithms for molecular dynamics typically take, as the target constraint lengths, the values of the equilibrium bond lengths defined in the potential. In Langevin form, the equations of motion are temperature dependent, which gives the average value for the individual bond lengths a temperature dependence. In addition to this, locally constant force fields can shift the local equilibrium bond lengths. To restore the average bond lengths in constrained integration to their unconstrained values, we suggest changing the constraint length used by popular constraint methods such as RATTLE [H. C. Andersen, J. Comput. Phys. 52, 23 (1983)] at each step. This allows us to more accurately capture the equilibrium bond length changes (with respect to the potential) due to the local equilibration and temperature effects. In addition, the approximations to the unconstrained nonbonded energies are closer using the dynamic constraint method than a traditional fixed constraint algorithm. The mechanism for finding the new constrained lengths involves one extra calculation of the bonded components of the force, and therefore adds O(N) time to the constraint algorithm. Since most molecular dynamics calculations are dominated by the O(N2) nonbonded forces, this new method does not take significantly more time than a fixed constraint algorithm.

Incidence of lymphoma in a large primary care derived cohort of cases of inflammatory polyarthritis

OBJECTIVE

To determine the risk of lymphoma in a primary care derived cohort of new onset cases of inflammatory polyarthritis and assess the contribution of disease severity and standard immunosuppressive treatment.

DESIGN

Prospective cohort study.

METHODS

2105 subjects with new onset inflammatory polyarthritis were recruited to the Norfolk Arthritis Register (NOAR) and followed annually for (median) 8.4 years. Occurrence of lymphoma was determined by annual morbidity review and linkage to the central hospital database serving the NOAR area. Cases of lymphoma were verified by record review. Standardised incidence ratios (SIRs) for lymphoma were calculated compared with the local, age, sex, and calendar year expected rates. Stratified analyses were undertaken for various markers of disease severity and treatment history.

RESULTS

There were 11 cases of lymphoma during 15,548 person years of follow up, the majority of which were of large B cell type. Compared with the local population the SIR was 2.4 (95% confidence interval, 1.2 to 4.2). The risks in cases classified as rheumatoid arthritis, ever rheumatoid factor positive, or ever treated with DMARDs were all higher, the highest risk group being those treated with methotrexate: SIR = 4.9 (1.8 to 10.6).

CONCLUSIONS

There was a doubling in risk of lymphoma in new onset cases of inflammatory polyarthritis. Patients with the most severe disease were twice as likely as other patients to develop lymphoma. These results need to be taken into account when considering reported increased risks of lymphoma compared to background population risk in users of new biological agents.

Knowledge of risk management strategies, and information and risk management preferences of women at increased risk for ovarian cancer

Little research is available on the level of knowledge about ovarian cancer risk management options in women at increased risk for this disease. The study objectives were to evaluate this together with the information and ovarian cancer risk management preferences of high-risk women. One hundred and twenty-nine women were assessed after their attendance at one of six familial cancer clinics in relation to knowledge of surveillance and/or preventative strategies for reduction of ovarian cancer risk, preferences for particular strategies, and information preferences. Screening was selected by 57 (44%) women as the preferred risk management option. One hundred and five women (82%) indicated a wish for as much information as possible about ovarian cancer, including both good and bad outcomes and 114 (89%) reported a preference for sharing treatment decisions with their health professional. Participants' knowledge about ovarian cancer risk management options was significantly associated with educational levels (Z = -3.2, p=0.001) and whether or not ovarian cancer was included in the family history (Z = -2.3, p = 0.018). Findings from this present study indicate that women at increased risk of ovarian cancer who attend familial cancer clinics want as much information as possible about this disease and they want to be involved in the decision-making process. Women who reported a lower level of education (no post-school qualifications) may be most likely to benefit from additional educational strategies designed to supplement genetic counseling to improve their knowledge levels.

Evaluation of the VIDAS Listeria (LIS) immunoassay for the detection of Listeria in foods using demi-Fraser and Fraser enrichment broths, as modification of AOAC Official Method 999.06 (AOAC Official Method 2004.06)

A multilaboratory study was conducted to compare the VIDAS LIS immunoassay with the standard cultural methods for the detection of Listeria in foods using an enrichment modification of AOAC Official Method 999.06. The modified enrichment protocol was implemented to harmonize the VIDAS LIS assay with the VIDAS LMO2 assay. Five food types--brie cheese, vanilla ice cream, frozen green beans, frozen raw tilapia fish, and cooked roast beef--at 3 inoculation levels, were analyzed by each method. A total of 15 laboratories representing government and industry participated. In this study, 1206 test portions were tested, of which 1170 were used in the statistical analysis. There were 433 positive by the VIDAS LIS assay and 396 positive by the standard culture methods. A Chi-square analysis of each of the 5 food types, at the 3 inoculation levels tested, was performed. The resulting average Chi square analysis, 0.42, indicated that, overall, there are no statistical differences between the VIDAS LIS assay and the standard methods at the 5% level of significance.

Phase I trial of intrathecal liposomal cytarabine in children with neoplastic meningitis

PURPOSE

We performed a phase I trial of intrathecal (IT) liposomal cytarabine (DepoCyt; Enzon Pharmaceuticals, Piscataway, NJ and SkyePharma Inc, San Diego, CA) to determine the maximum-tolerated dose, the dose-limiting toxicities, and the plasma and CSF pharmacokinetics of IT lipsomal cytarabine in children >/= 3 years of age with advanced meningeal malignancies.

PATIENTS AND METHODS

Eighteen assessable patients received IT liposomal cytarabine through either an indwelling ventricular access device or via lumbar puncture. Liposomal cytarabine was given once every 2 weeks during induction, once every 4 weeks during consolidation, and once every 8 weeks during the maintenance phase of treatment. The initial dose was 25 mg, with subsequent escalations to 35 and 50 mg. CSF pharmacokinetic samples were obtained in a subset of patients.

RESULTS

Arachnoiditis, characterized by fever, headache, nausea, vomiting, and back pain was noted in the first two patients at the 25 mg dose level. Therefore, subsequent patients were treated with dexamethasone, beginning the day of liposomal cytarabine administration and continuing for 5 days. Headache (grade 3) was dose limiting in two of eight patients enrolled at the 50 mg dose level. Eight of the 14 patients assessable for response demonstrated evidence of benefit manifest as prolonged disease stabilization or response.

CONCLUSION

The maximum-tolerated dose and recommended phase II dose of liposomal cytarabine in patients between the ages of 3 and 21 years is 35 mg, administered with dexamethasone (0.15 mg/kg/dose, twice a day for 5 days). A phase II trial of IT liposomal cytarabine in children with CNS leukemia in second or higher relapse is in development.

Oscillatory axial banding of particles suspended in a rotating fluid

A nonviscous fluid, completely filling a tube rotating about its horizontal axis, contains a suspension of macroscopic particles. The particles are observed to distribute themselves spontaneously in bands distributed periodically along the axis, with a band separation dependent only on the tube radius and length. In many cases, the bands oscillate periodically between two interleaving patterns. We explain this banding phenomenon as arising from the excitation of inertial standing waves in the rotating fluid.

14-day variant of the bleomycin, etoposide, doxorubicin, cyclophosphamide, vincristine, procarbazine, and prednisone regimen in advanced-stage Hodgkin's lymphoma: results of a pilot study of the German Hodgkin's Lymphoma Study Group

PURPOSE

This multicenter pilot study assessed the feasibility and efficacy of a time-intensified bleomycin, etoposide, doxorubicin, cyclophosphamide, vincristine, procarbazine, and prednisone (BEACOPP) regimen given in 14-day intervals (BEACOPP-14) with granulocyte colony-stimulating factor (G-CSF) support in advanced Hodgkin's lymphoma.

PATIENTS AND METHODS

From July 1997 until March 2000, 94 patients with Hodgkin's lymphoma stage IIB, III, and IV were scheduled to receive eight cycles of BEACOPP-14. Consolidation radiotherapy was administered to regions with initial bulky disease or residual tumor after chemotherapy.

RESULTS

All patients were assessable for toxicity and treatment outcome. Eighty-six patients received the planned eight cycles of BEACOPP-14. Consolidation radiotherapy was given in 66 patients. Chemotherapy could generally be administered on schedule. Dose reductions varied among drugs but were generally low. Acute toxicity was moderate, with World Health Organization grade 3/4 leukopenia in 75%, thrombocytopenia in 23%, anemia in 65%, and infection in 12% of patients. A total of 88 patients (94%) achieved a complete remission. Four patients had progressive disease. At a median observation time of 34 months, five patients have relapsed, one patient developed a secondary non-Hodgkin's lymphoma, and three deaths were documented. The overall survival and freedom from treatment failure rates at 34 months were 97% (95% confidence interval [CI], 93% to 100%) and 90% (95% CI, 84% to 97%), respectively.

CONCLUSION

Acceleration of the BEACOPP baseline regimen by shortening cycle duration with G-CSF support is feasible and effective with moderate acute toxicity. On the basis of these results, the German Hodgkin's Lymphoma Study Group will compare the BEACOPP-14 regimen with BEACOPP-21 escalated in a prospective multicenter randomized trial.

Signalling and anti-proliferative effects mediated by gonadotrophin-releasing hormone receptors after expression in prostate cancer cells using recombinant adenovirus

Gonadotrophin-releasing hormone receptors (GnRH-Rs) are found in cancers of reproductive tissues, including those of the prostate, and gonadotrophin-releasing hormone (GnRH) can inhibit growth of cell lines derived from such cancers. Although pituitary and extra-pituitary GnRH-R transcripts appear identical, their functional characteristics may differ. Most extra-pituitary GnRH-Rs have low affinity for GnRH analogues and may not activate phospholipase C or discriminate between agonists and antagonists in the same way as do pituitary GnRH-Rs. Here we have assessed whether GnRH-Rs expressed exogenously in prostate cancer cells differ functionally from those of gonadotrophs. We found no evidence for endogenous GnRH-Rs in PC3 cells, but after infection with adenovirus expressing the GnRH-R (Ad GnRH-R) at 10 plaque forming units (p.f.u.)/cell or greater, at least 80% of the cells expressed GnRH-Rs. These sites had high affinity (K(d )for [(125)I]Buserelin 1.1+/-0.4 nM) and specificity (rank order of potency: Buserelin> GnRH>>chicken (c) GnRH-II), and mediated stimulation of [(3)H]inositol phosphate (IP) accumulation. Increasing viral titre from 3 to 300 p.f.u./cell increased receptor number (2000 to 275 000 sites/cell respectively) and [(3)H]IP responses. GnRH also caused a biphasic increase in the cytoplasmic Ca(2+) concentration in Ad GnRH-R-infected cells but not in control cells. Mobilization of Ca(2+) from intracellular stores contributed to the spike phase of this response whereas the plateau phase was dependent upon Ca(2+) entry across the plasma membrane. This effect on Ca(2+) and stimulation of [(3)H]IP accumulation were both blocked by the GnRH-R antagonist, Cetrorelix. In addition, GnRH reduced cell number (as measured in MTT activity assays) and DNA synthesis (as measured by [(3)H]thymidine incorporation) in Ad GnRH-R-infected cells (but not in control cells). This effect was mimicked by agonist analogues and inhibited by two antagonists. Thus, when exogenous GnRH-Rs are expressed at a density comparable to that in gonadotrophs, they are functionally indistinguishable from the endogenous GnRH-Rs in gonadotrophs. Moreover, expression of high affinity GnRH-Rs can facilitate a direct anti-proliferative effect of GnRH agonists on prostate cancer cells.

Current clinical trials for the treatment of advanced-stage Hodgkin's disease: BEACOPP

BACKGROUND

The bleomycin-etoposide-doxorubicin-cyclophosphamide-vincristine-procarbazine-prednisone (BEACOPP) regimen was developed to investigate the potential of moderate dose escalation of conventional polychemotherapy to improve the unsatisfactory treatment results in advanced-stage Hodgkin's lymphoma (HL). Following pilot studies, the randomised trial HD 9 demonstrated that BEACOPP (baseline dose) attained superior failure-free survival to COPP/ABVD, and that dose escalation made a further marked improvement. Toxicity was severe but manageable.

PATIENTS AND METHODS

The current GHSG multicentre randomised trial HD 12 has a 2 x 2 factorial design in order to make two comparisons: (i) eight cycles of escalated BEACOPP (as in HD9) are compared with four escalated cycles followed by four at baseline dose; (ii) the use of additional local radiotherapy to initial bulky disease and residual disease after chemotherapy is compared with chemotherapy alone, except where radiotherapy was prescribed by a central diagnostic panel. Eligible are patients aged 16-65 years with newly diagnosed HL of stage IIB with risk factors or stage III/IV. The EORTC multicentre trial 20012 randomises patients with HL stage III/IV to either eight cycles of ABVD or eight cycles of BEACOPP (four escalated + four baseline).

RESULTS

The first interim analysis (January 2001) of HD 12 with 221 evaluable patients indicated continuation of recruitment. Recruitment will end in 2002 and the final data analysis will appear in 2006.

CONCLUSIONS

The BEACOPP regimen is highly effective, and moderate dose escalation makes a further worthwhile improvement in tumour control. Current trials will measure BEACOPP against the international standard and show whether the amount of chemotherapy and/or radiotherapy can be reduced.

Early response to chemotherapy: a surrogate for final outcome of Hodgkin's disease patients that should influence initial treatment length and intensity?

BACKGROUND

Early adjustment of treatment may benefit the patient. In order to guide treatment adjustment, use of early response (ER) or early complete response (ECR), judged after the few initial cycles of chemotherapy, is common in pediatric and also adult Hodgkin's and non-Hodgkin's studies. Paradoxically, almost no data support this strategy.

PATIENTS AND METHODS

The influence of ECR on outcome was evaluated in three series of advanced Hodgkin's disease (HD), leading to a series of questions.

RESULTS

The 1982 EORTC study assessed prospectively the time frame needed to reach an apparent complete response (CR) through repeated tumor measurements. In patients assessed at mid-treatment before the fifth cycle, both 15 year freedom from progression (FFP) and overall survival (OS) were superior in ECR patients compared with other patients continued on the same treatment (61% versus 37%; P < 0.001). A series of questions arise from these observations. Question 1: is the shortening of treatment detrimental? In a randomized Swedish trial, in one arm treatment was shortened in patients evaluated from the fifth cycle as ECR as compared with the standard eight cycles arm, 10 year cause-specific-survival (CSS) was 53 versus 69% [not significant (ns)]; 10 year OS 49% versus 58% (ns). Conversely, in the EORTC 20884 study, ECR patients given only six cycles did as well as patients entering CR later and, for this reason, given eight cycles (identical 6 year event-free survival 75%). Question 2: is early treatment adaptation in patients who failed to reach ER beneficial? In the French MDH 90 trial, 15% of children failed to reach ECR after four cycles; in these children only, anthracyclines plus alkylating agents were given and the dose of radiotherapy increased, improving the results observed in the previous trial. In the EORTC 20884 study, patients who failed to reach an ECR were switched earlier to involved field RT: their results matched those of ECR patients, at the difference of the previous trial. Question 3: is ER a predicting factor that can be used with any type of treatment? Probably not, based on the German Hodgkin's Lymphoma Study Group trial HD 9: ECR is highly dependent on specific interval from treatment start and on treatment intensity.

DISCUSSION

More general questions stem from these results. Question 4: is the definition of ER secured? With conventional imaging, the different methods for response assessment at end treatment also lead to different response rates; the assessment in the middle of treatment itself and the use of newer imaging techniques may further increase the variation. Indeed, question 5 is: is ER a concept based on any biology? Correlation to markers, 99mTc uptake, PET and hematological tolerance might help to pinpoint how and why ER represents a surrogate for final outcome.

CONCLUSION

ER is a surrogate for final outcome, reflecting both tumor burden and activity. This predictability may, and possibly should, impact on treatment.

The gonadotrophin-releasing hormone receptor: signalling, cycling and desensitisation

Sustained stimulation of G-protein coupled receptors (GPCRs) typically causes receptor desensitisation that is mediated by phosphorylation, often within the C-terminal tail of the receptor. The consequent binding of beta-arrestin not only prevents the receptor from activating its G-protein (causing desensitisation) but can also target it for internalisation via clathrin-coated vesicles and can mediate signalling to proteins regulating endocytosis and mitogen-activated protein kinase (MAPK) cascades. GnRH acts via phospholipase C coupled GPCRs on pituitary gonadotrophs. The type I GnRH-receptors (GnRH-Rs) found only in mammals, are unique in that they lack C-terminal tails and apparently do not undergo agonist-induced phosphorylation or bind beta-arrestin. They are therefore resistant to receptor desensitisation and internalise slowly. In contrast, the type II GnRH-Rs, found in numerous vertebrates, possess such tails and show rapid desensitisation and internalisation with concomitant receptor phosphorylation (within the C-terminal tails) and/or binding of beta-arrestin. The binding to beta-arrestin may also be important for association with dynamin, a GTPase that controls cleavage of endosomes from the plasma membrane. Using recombinant adenovirus to express GnRH-R, we have found that blockade of dynamin-dependent endocytosis inhibits internalisation of type II (Xenopus) GnRH-Rs but not type I (human) GnRH-Rs, revealing the existence of functionally distinct routes through which these receptors are internalised. Although type I GnRH-R do not rapidly desensitise, sustained activation of GnRH receptors does cause desensitisation of gonadotrophin secretion, an effect which must therefore involve adaptive responses distal to the receptor. One such response is the GnRH-induced down regulation of inositol 1, 4, 5 trisphosphate receptors that apparently underlies desensitisation of Ca2+ mobilisation in a gonadotroph-derived cell line. Although activation of other GPCRs can down-regulate inositol 1, 4, 5 trisphosphate receptors, the effect of GnRH is atypically rapid and pronounced, presumably because of the receptor's atypical resistance to desensitisation. GnRH-Rs are also expressed in several extra-pituitary sites and these may mediate direct inhibition of proliferation of hormone-dependent cancer cells. Infection with type I GnRH-R expressing adenovirus facilitated expression of high affinity, PLC-coupled GnRH-R in mammary and prostate cancer cells and these mediated pronounced antiproliferative effects of receptor agonists. No such effect was seen in cells transfected with a type II GnRH-R, implying that it is mediated most efficiently by a non-desensitising receptor. Thus it appears that the GnRH-Rs have undergone a period of rapidly accelerated molecular evolution that is of functional relevance to GnRH-R signalling in pituitary and extra-pituitary sites.

Signalling, cycling and desensitisation of gonadotrophin-releasing hormone receptors

Sustained stimulation of G-protein-coupled receptors (GPCRs) typically causes receptor desensitisation, which is mediated by phosphorylation, often within the C-terminal tail of the receptor. The consequent binding of beta-arrestin not only prevents the receptor from activating its G protein (causing desensitisation), but can also target it for internalisation via clathrin-coated vesicles and can mediate signalling to proteins regulating endocytosis and mitogen-activated protein kinase (MAPK) cascades. GnRH acts via phospholipase C (PLC)-coupled GPCRs on pituitary gonadotrophs to stimulate a Ca(2+)-mediated increase in gonadotrophin secretion. The type I GnRH receptors (GnRH-Rs), found only in mammals, are unique in that they lack C-terminal tails and apparently do not undergo agonist-induced phosphorylation or bind beta-arrestin; they are therefore resistant to receptor desensitisation and internalise slowly. In contrast, the type II GnRH-Rs, found in numerous vertebrates, possess such tails and show rapid desensitisation and internalisation, with concomitant receptor phosphorylation (within the C-terminal tails) or binding of beta-arrestin, or both. The association with beta-arrestin may also be important for regulation of dynamin, a GTPase that controls separation of endosomes from the plasma membrane. Using recombinant adenovirus to express GnRH-Rs in Hela cells conditionally expressing a dominant negative mutant of dynamin (K44A), we have found that blockade of dynamin-dependent endocytosis inhibits internalisation of type II (xenopus) GnRH-Rs but not type I (human) GnRH-Rs. In these cells, blockade of dynamin-dependent internalisation also inhibited GnRH-R-mediated MAPK activation, but this effect was not receptor specific and therefore not dependent upon dynamin-regulated GnRH-R internalisation. Although type I GnRH-Rs do not desensitise, sustained activation of GnRH-Rs causes desensitisation of gonadotrophin secretion, and we have found that GnRH can cause down-regulation of inositol (1,4,5) trisphosphate receptors and desensitisation of Ca(2+) mobilisation in pituitary cells. The atypical resistance of the GnRH-R to desensitisation may underlie its atypical efficiency at provoking this downstream adaptive response. GnRH-Rs are also expressed in several extrapituitary sites, and these may mediate direct inhibition of proliferation of hormone-dependent cancer cells. Infection with type I GnRH-R-expressing adenovirus facilitated expression of high-affinity, PLC-coupled GnRH-R in mammary and prostate cancer cells, and these mediated pronounced antiproliferative effects of receptor agonists. No such effect was seen in cells transfected with a type II GnRH-R, implying that it is mediated most efficiently by a non-desensitising receptor. Thus it appears that the mammalian GnRH-Rs have undergone a period of rapidly accelerated molecular evolution that is of functional relevance to GnRH-Rs in pituitary and extrapituitary sites.

Whole-body positron emission tomography using 18F-fluorodeoxyglucose for initial staging of patients with Hodgkin's disease

An accurate initial staging of patients with Hodgkin's disease (HD) is important for the evaluation of clinical stage and risk factors, which are crucial for the choice of an appropriate treatment. 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET) is useful for detecting active tumor tissue in patients with lymphoproliferative diseases and may contribute to conventional staging methods in patients with HD. Twenty-two patients who presented with newly diagnosed HD underwent conventional staging methods including computed tomography (CT) as well as FDG PET. Lesions apparent in FDG PET and CT were correlated to each other. Seventy-seven lesions were observed either in PET or CT or in both. In 48 (62%) lesions PET and CT were both positive. In 20 (26%) sites, PET was positive and CT negative. Of 22 patients (18%) 4 were upstaged due to these positive PET findings, and as a result one patient received a different therapeutic regimen. PET failed to detect nine (12%) CT-positive sites in six patients. Statistically, these data are reflected by a sensitivity for PET and CT of 88% and 74%, respectively. Specificity of both imaging modalities was 100%. PET can contribute valuable information as an additional staging examination and led to an upstaging in some patients with primary HD. However, PET should not be used as the only imaging modality as it failed to detect CT-positive, active tumor regions in some cases.

Delayed emergency department presentation in critically ill patients

OBJECTIVES

To determine the frequency and causes of delayed emergency department presentation in critically ill patients who did not have acute myocardial infarction and to evaluate whether factors such as age, gender, prior medical advice, lack of insurance, or low educational level are associated with delayed presentation.

DESIGN

Prospective, descriptive analysis.

SETTING

Emergency department and medical intensive care unit of an urban county hospital.

PATIENTS

All adult patients admitted from the emergency department to the medical intensive care unit for reasons other than unstable angina, acute myocardial infarction, or stroke over two 9-wk blocks.

INTERVENTIONS

Within 72 hrs of intensive care unit admission, patients or their families were interviewed to determine time elapsed between the onset of symptoms and patient emergency department presentation and to elicit reasons for delays in seeking medical treatment.

MEASUREMENTS AND MAIN RESULTS

We interviewed 155 of 173 (90%) of eligible patients and found that 58% waited >24 hrs before presenting to the emergency department. The most commonly cited primary reason for delays were beliefs that symptoms were not serious enough for emergency care (31%) and that symptoms would resolve spontaneously (29%). Most (55%) sought medical treatment only at the urging of family members or other advocates. Although variables such as lack of insurance and low educational level were not associated with delayed presentation, male gender and having sought medical advice before presenting to the emergency department were significantly associated with delay (p =.036 for each).

CONCLUSIONS

Because of poor understanding of the gravity and natural progression of their symptoms, most critically ill patients waited >24 hrs to present to our emergency department. Education on warning symptom recognition for serious illnesses may be warranted not only for patients themselves but also for family members and caregivers.