A polymorphism in the enhancer region of the thymidylate synthase promoter influences the survival of colorectal cancer patients treated with 5-fluorouracil

High levels of thymidylate synthase (TS) expression have been associated with poor survival of colorectal cancer (CRC) patients to 5-fluorouracil (5-FU)-based chemotherapy. Recent evidence suggests that a polymorphism within the enhancer region of the TS gene promoter can influence TS expression, with the triple repeat homozygote (3R/3R) being associated with significantly higher tumour TS levels than either the double repeat homozygote (2R/2R) or heterozygotes (2R/3R). In the present study we investigated whether TS genotype was associated with the degree of survival benefit from chemotherapy in 221 Dukes' C stage CRC patients. Patients with the 3R/3R polymorphism (n = 58, 26%) showed no significant long-term survival benefit from chemotherapy (RR = 0.62, 95% CI: 0.30-1.25, P = 0.18), whereas those with the 2R/2R or 2R/3R genotype (n = 163, 74%) showed significant gains in survival from this treatment (RR = 0.52, 95% CI: 0.52-0.82, P = 0.005). These results demonstrate that a polymorphism within the TS gene, probably through its effect on TS expression levels, can influence the survival benefit obtained by CRC patients from 5-FU-based chemotherapy.

Early toxicity from preoperative radiotherapy with continuous infusion 5-fluorouracil for resectable adenocarcinoma of the rectum: a Phase II trial for the Trans-Tasman Radiation Oncology Group

PURPOSE

To assess the toxicity and the efficacy of preoperative radiotherapy with continuous infusion 5-fluorouracil (5-FU) for locally advanced adenocarcinoma of the rectum.

METHODS AND MATERIALS

Eligible patients had newly diagnosed localized adenocarcinoma of the rectum within 12 cm of the anal verge, Stage T3-4, and were suitable for curative resection. Eighty-two patients were treated with radiotherapy-50.4 Gy in 28 fractions in 5.6 weeks, given concurrently with continuous infusion 5-FU, using either 96-h/week infusion at 300 mg/m(2)/day or 7-days/week infusion at 225 mg/m(2)/day.

RESULTS

The median age was 59 years (range, 27-87), and 67% of patients were male. Pretreatment stages of the rectal cancer were T3, 89% and resectable T4, 11%, with endorectal ultrasound confirmation in 67% of patients. Grade 3 acute toxicity occurred in 5 of 82 patients (6%; 95% confidence interval [CI], 2-14%). Types of surgical resection were anterior resection, 61%; abdominoperineal resection, 35%; and other procedures, 4%. There was no operative mortality. Anastomotic leakage after low anterior resection occurred in 3 of 50 patients (6%; 95% CI, 1-17%). The pathologic complete response rate was 16% (95% CI, 9-26%). Pathologic Stages T2 or less occurred in 51%.

CONCLUSION

Preoperative radiotherapy with continuous infusion 5-FU for locally advanced rectal cancer is a safe regimen, with a significant downstaging effect. It does not seem to lead to a significant increase in serious surgical complications.

Accumulation of free 3-hydroxy fatty acids in the culture media of fibroblasts from patients deficient in long-chain l-3-hydroxyacyl-CoA dehydrogenase: a useful diagnostic aid

BACKGROUND

The diagnosis of long-chain L-3-hydroxy-acyl-coenzyme A dehydrogenase (LCHAD) deficiency frequently requires the study of cultured fibroblasts. We developed such a test that does not require disruption and loss of the cells.

METHODS

We measured free 3-hydroxy fatty acids (3-OHFAs) in media of skin fibroblasts cultures from 11 patients with a genetic deficiency of LCHAD and the associated disorder of mitochondrial trifunctional protein (MTFP). Fibroblasts were cultured for 24 h with 100 micromol/L nonisotopic palmitate added. 3-OHFAs were measured by selected-ion monitoring, stable-isotope dilution gas chromatography-mass spectrometry with [(13)C]-labeled internal standards.

RESULTS

3-OH-hexadecanoic and 3-OH-tetradecanoic FAs were increased 14- and 11-fold, respectively, in all patients with LCHAD or MTFP deficiency when compared with control fibroblast cell lines after overnight incubation with palmitate. 3-OH-dodecanoic FA demonstrated a modest, fivefold increase in LCHAD-deficient cells. The concentrations of all 3-OHFAs were similar whether or not the medium samples were hydrolyzed to release conjugated species such as acylcarnitines, suggesting that 3-OHFAs accumulate in the media as free FAs.

CONCLUSIONS

Measurement of 3-OHFA excretion from LCHAD- or MTFP-deficient cell lines can be used as a diagnostic tool. Free FAs are the predominant form of these abnormal metabolic intermediates in culture media.

Cerebrospinal fluid cutaneous fistula after labour epidural analgesia

We report a case of cerebrospinal fluid cutaneous fistula in a previously healthy patient who had seemingly uneventful lumbar epidural analgesia for labour.

P53 alteration and microsatellite instability have predictive value for survival benefit from chemotherapy in stage III colorectal carcinoma

PURPOSE

We recently presented evidence for tumor site and gender-specificity in the survival benefit from adjuvant chemotherapy in Stage III colorectal cancer (CRC). In the current study, we examined whether p53 alteration or the microsatellite instability (MSI) phenotype provide additional predictive information in CRC patients.

EXPERIMENTAL DESIGN

A retrospective series of 891 Stage III CRC patients with negative surgical margins was investigated. Thirty percent (270 of 891) received postoperative adjuvant chemotherapy with curative intent and comprising of 5-fluorouracil/levamisole. Adjuvant treatment and nontreatment patient groups were well matched for tumor site, grade, p53 alterations, and MSI. Surgical tumor specimens were investigated for p53 overexpression using immunohistochemistry and for p53 mutation and MSI using single-strand conformation polymorphism analysis. The predictive value of these markers was evaluated by comparing the survival of adjuvant-treated and nonadjuvant treated patients.

RESULTS

A strong inverse correlation was observed between p53 alteration and MSI (P < 0.0001). In univariate analysis, the factors of sex, site, p53 alteration, and MSI were each strong predictors of a survival benefit from chemotherapy. Multivariate analysis revealed that chemotherapy provided maximal survival benefit for female patients (P = 0.005) and for patients whose tumors contained normal p53 (P = 0.041). Males whose tumors contained a p53 alteration and were negative for MSI appeared not to benefit from chemotherapy.

CONCLUSIONS

Our findings suggest that p53 alteration and MSI could be clinically useful molecular predictive markers for the identification of CRC patients who might benefit from 5-fluorouracil-based chemotherapy.

Golgi complex reorganization during muscle differentiation: visualization in living cells and mechanism

During skeletal muscle differentiation, the Golgi complex (GC) undergoes a dramatic reorganization. We have now visualized the differentiation and fusion of living myoblasts of the mouse muscle cell line C2, permanently expressing a mannosidase-green fluorescent protein (GFP) construct. These experiments reveal that the reorganization of the GC is progressive (1-2 h) and is completed before the cells start fusing. Fluorescence recovery after photobleaching (FRAP), immunofluorescence, and immunogold electron microscopy demonstrate that the GC is fragmented into elements localized near the endoplasmic reticulum (ER) exit sites. FRAP analysis and the ER relocation of endogenous GC proteins by phospholipase A2 inhibitors demonstrate that Golgi-ER cycling of resident GC proteins takes place in both myoblasts and myotubes. All results support a model in which the GC reorganization in muscle reflects changes in the Golgi-ER cycling. The mechanism is similar to that leading to the dispersal of the GC caused, in all mammalian cells, by microtubule-disrupting drugs. We propose that the trigger for the dispersal results, in muscle, from combined changes in microtubule nucleation and ER exit site localization, which place the ER exit sites near microtubule minus ends. Thus, changes in GC organization that initially appear specific to muscle cells, in fact use pathways common to all mammalian cells.

Effects of Mycobacterium bovis BCG on the development of allergic inflammation and bronchial hyperresponsiveness in hyper-IgE BP2 mice vaccinated as newborns

Asthma may result from excessive Th-2 response in children not previously exposed to Th-1-inducing infections. We tested the hypothesis that BCG vaccination in Th-2-susceptible newborn BP2 mice blocks allergic inflammation and bronchial hyperreactivity (BHR). Ten day-old BP2 mice received 10(5) CFU of BCG 1173P2 intranasally (IN), and 6, 10 or 14 weeks thereafter were sensitized with 100 microg ovalbumin (OVA) in aluminium hydroxide twice subcutaneously (SC) at 1 week interval, and challenged 1 week after the second sensitization with 10 microg OVA IN. Compared to OVA-challenged unvaccinated mice, those that received BCG 8 weeks before challenge developed intense bronchial inflammation, BHR, and high IgE titers. Inflammation involved T cells, macrophages, dendritic cells and was accompanied by increased levels of Interleukin-5 (IL-5) in the bronchoalveolar lavages (BAL). However, animals challenged 16 weeks after BCG vaccination did not develop BHR nor bronchial hypereosinophilia, and showed reduced IgE levels. Bronchial infiltration by immunocompetent cells was also significantly reduced. Increased levels of gamma-interferon (IFN-gamma) after in vitro stimulation of tracheo-bronchial lymph node cells accompanied this blockage, but levels of IL-5 remained high. We demonstrate that 16 weeks after vaccination with BCG in newborn BP2 mice which have a high Th-2 background, allergic inflammation and BHR were blocked, even though a clear Th-1 shift was not achieved.

Prognostic significance of TP53 gene mutation in 995 cases of colorectal carcinoma. Influence of tumour site, stage, adjuvant chemotherapy and type of mutation

Previous studies on the prognostic significance of TP53 gene alterations in colorectal cancer (CRC) have led to conflicting results. The present study investigated the prognostic significance of TP53 gene mutation in a very large series of 995 Dukes' B and C CRC patients, the majority of whom did not receive chemotherapy. Mutations were found in 385 (39%) cases and were not associated with tumour stage, histological grade, patient age or sex. Significantly more mutations were found in tumours from the left-sided colon compared with those from the right side (43% versus 34%, P=0.006). TP53 gene mutation had no prognostic value in the overall series or in different site or stage subgroups. None of the different types of TP53 gene mutation showed prognostic value. A trend for association with worse survival was observed in the patient subgroup that received adjuvant chemotherapy (Hazard Ratio (HR) 1.4, 95% confidence interval (CI) 0.89-2.21, P=0.15). These results indicate that mutation of the TP53 gene is not a useful prognostic marker for CRC patients who do not receive adjuvant chemotherapy. Further study is required to determine whether different types of TP53 mutation might be of value in predicting the response of CRC patients to chemotherapy.

Can p53 alterations be used to predict tumour response to pre-operative chemo-radiotherapy in locally advanced rectal cancer?

PURPOSE

To examine whether p53 tumour suppressor gene alterations can be used to predict tumour response to pre-operative chemo-radiation in locally advanced rectal cancer in terms of reduction in tumour size and local failure.

METHODS

p53 alterations were studied in pre-treatment biopsy specimens of rectal carcinomas from 48 patients by immunohistochemistry (IHC) and polymerase chain reaction/single strand conformation polymorphism (PCR-SSCP) gene mutation analysis. Pre-operative pelvic radiotherapy was delivered with four fields, 45 Gy to the ICRU point in 25 fractions over 5 weeks. A radio-sensitising dose of 5-fluorouracil (500 mg/m(2)) was delivered concurrently for 6 days of the 5-week schedule (days 1, 2, 3 and days 22, 23 and 24). Total meso-rectal excision was planned 4 to 6 weeks from completion of pre-operative treatment. Response to therapy was assessed by macroscopic measurement of the surgical specimen by a pathologist who was unaware of the pre-treatment tumour size or of the p53 status.

RESULTS

IHC evidence of p53 protein accumulation was found in 40% of tumours, p53 gene mutation in 35% and p53 alteration (either or both changes) in 46%. The average reduction in tumour size was 53% in the group with 'wild-type' p53 (IHC-/SSCP-) and 63% in the group with altered p53 (either IHC+ or SSCP+; P=0.18). No significant differences in tumour size reduction or local failure were observed in the groups with p53 overexpression or p53 mutation compared with normal.

CONCLUSIONS

p53 alteration detected by IHC or SSCP analysis is not a clinically useful predictor of local response to pre-operative adjuvant therapy in advanced rectal carcinoma.

Association of tumour site and sex with survival benefit from adjuvant chemotherapy in colorectal cancer

BACKGROUND

Adjuvant chemotherapy can improve 5-year survival in Dukes' C colorectal carcinoma. Improved selection of patients who will respond to adjuvant treatments is required. We investigated whether site of tumour origin, sex, and presence of microsatellite instability (MSI) phenotype were associated with a survival benefit from adjuvant chemotherapy.

METHODS

We analysed data for 656 consecutive patients with Dukes' C colorectal carcinoma, with median follow-up of 54 months (range 7-104) and mean age 66.7 years (SD 12.9). We screened tumour samples by PCR for deletions in the BAT-26 mononucleotide repeat to establish MSI status. Details of chemotherapy and survival were obtained by review of hospital and health-department records. Adjuvant chemotherapy (fluorouracil and levamisole) was given with curative intent to 272 (42%) patients.

FINDINGS

Striking survival benefits were seen for patients who had right-sided tumours and who received adjuvant chemotherapy compared with those who did not (48 vs 27% alive at end of study [95% CI 0.25-0.56], p<0.0001), for women (53 vs 33% [0.25-0.56], p<0.0001), and for patients with MSI tumours (90 vs 35% [0.01-0.53], p=0.0007). MSI-positive tumours were slightly more frequent in women than in men (10 vs 7%). Right-sided tumours were more frequently MSI positive than left-sided tumours (20 vs 1%). Men with right-sided tumours benefited from chemotherapy (37 vs 12% [0.24-0.69], p=0.0007) but men with left-sided tumours did not.

INTERPRETATION

The survival benefits seen in patients treated with adjuvant chemotherapy suggest that data from previous trials of adjuvant chemotherapy should be reassessed and the predictive value of MSI status confirmed. Validation of our results will allow better selection of patients for chemotherapy.

Association of tumour site and sex with survival benefit from adjuvant chemotherapy in colorectal cancer

BACKGROUND

Adjuvant chemotherapy can improve 5-year survival in Dukes' C colorectal carcinoma. Improved selection of patients who will respond to adjuvant treatments is required. We investigated whether site of tumour origin, sex, and presence of microsatellite instability (MSI) phenotype were associated with a survival benefit from adjuvant chemotherapy.

METHODS

We analysed data for 656 consecutive patients with Dukes' C colorectal carcinoma, with median follow-up of 54 months (range 7-104) and mean age 66.7 years (SD 12.9). We screened tumour samples by PCR for deletions in the BAT-26 mononucleotide repeat to establish MSI status. Details of chemotherapy and survival were obtained by review of hospital and health-department records. Adjuvant chemotherapy (fluorouracil and levamisole) was given with curative intent to 272 (42%) patients.

FINDINGS

Striking survival benefits were seen for patients who had right-sided tumours and who received adjuvant chemotherapy compared with those who did not (48 vs 27% alive at end of study [95% CI 0.25-0.56], p<0.0001), for women (53 vs 33% [0.25-0.56], p<0.0001), and for patients with MSI tumours (90 vs 35% [0.01-0.53], p=0.0007). MSI-positive tumours were slightly more frequent in women than in men (10 vs 7%). Right-sided tumours were more frequently MSI positive than left-sided tumours (20 vs 1%). Men with right-sided tumours benefited from chemotherapy (37 vs 12% [0.24-0.69], p=0.0007) but men with left-sided tumours did not.

INTERPRETATION

The survival benefits seen in patients treated with adjuvant chemotherapy suggest that data from previous trials of adjuvant chemotherapy should be reassessed and the predictive value of MSI status confirmed. Validation of our results will allow better selection of patients for chemotherapy.

Screening of new antioxidant molecules using flow cytometry

We present a flow cytometry technique to evaluate the antioxidative properties of molecules on living cells, using a stable murine-murine hybridoma (Mark 3) cell line routinely cultured. Using this technique, intracellular superoxide anions and peroxides were evaluated with dihydrorhodamine (DHR-123) and dichlorofluorescein diacetate (DCFH-DA), respectively. When cells were first incubated for 10 min with either H(2)O(2) or the xanthine (X)/xanthine oxidase (XO) system, this flow cytometric technique was capable of evaluating the oxidative stress on cells. Twenty-one new analogues of ellipticine were synthesized and tested for their antioxidative properties compared to vitamin E and Ebselen used as references. A good statistical reflection of the antioxidative activities of these molecules was achieved by analyzing 35 000 cells in each experiment. Among them, the selenated molecule 18 was found to be 10 times more active than Ebselen but 10 000 times less active than vitamin E. Moreover, eight compounds showed glutathione peroxidase-like activities.

Upregulation by glucocorticoids of responses to eosinopoietic cytokines in bone-marrow from normal and allergic mice

Since the production of eosinopoietic cytokines (GM-CSF, IL-3, IL-5) is inhibited by glucocorticoids, while responsiveness to these cytokines is enhanced in bone-marrow of allergic mice, we studied the ability of glucocorticoids to modulate murine bone-marrow eosinopoiesis. Progenitor (semi-solid) and/or precursor (liquid) cultures were established from bone-marrow of: (a) normal mice; (b) ovalbumin-sensitized and challenged mice or (c) dexamethasone (1-5 mg kg(-1)) injected mice. Cultures were established with GM-CSF (2 ng ml(-1)) or IL-5 (1 ng ml(-1)), respectively, alone or associated with dexamethasone, hydrocortisone or corticosterone. Total myeloid colony numbers, frequency and size of eosinophil colonies, and numbers of eosinophil-peroxidase-positive cells were determined at day 7. In BALB/c mice, dexamethasone (10(-7) M) increased GM-CSF-stimulated myeloid colony formation (P = 0.01), as well as the frequency (P=0.01) and size (P<0.01) of eosinophil colonies. Dexamethasone (10(-7) M) alone had no effect. Dexamethasone (10(-7)-10(-10) M) increased (P<0.002) eosinophil precursor responses to IL-5. Potentiation by dexamethasone was still detectable: (a) on low density, immature, nonadherent BALB/c bone-marrow cells, (b) on bone-marrow from other strains, and (c) on cells from allergic mice. Hydrocortisone and corticosterone had similar effects. Dexamethasone administered in vivo, 24 h before bone-marrow harvest, increased subsequent progenitor responses to GM-CSF (P = 0.001) and precursor responses to IL-5 (P<0.001). These effects were blocked by RU 486 (20 mg kg(-1), orally, 2 h before dexamethasone, or added in vitro at 10 microM, P<0.001). Glucocorticoids, acting in vivo or in vitro, through glucocorticoid receptors, enhance bone-marrow eosinopoiesis in naïve and allergic mice.

p53 gene mutation, microsatellite instability and adjuvant chemotherapy: impact on survival of 388 patients with Dukes' C colon carcinoma

Two common genetic alterations in colon carcinoma, p53 mutation and microsatellite instability (MSI), were investigated to determine their prognostic importance for cancer-specific survival and response to adjuvant chemotherapy in patients with Dukes' C colon cancer. The p53 tumour suppressor gene encodes for a nuclear phosphoprotein involved in cellular response to DNA damage, while MSI is a characteristic feature of tumours with defective DNA mismatch repair. The cellular response mechanisms to DNA-damaging agents in tumours with mutant p53 or MSI may as a consequence differ, and this might translate into different outcomes following adjuvant chemotherapy. A consecutive series of 388 Dukes' C colon carcinomas with 5-year median follow-up was analysed for p53 mutation and for MSI (in proximal/transverse carcinomas only) using polymerase chain reaction single-strand conformation polymorphism. The incidence of p53 mutation was 28% in all carcinomas while that of MSI in proximal/transverse carcinomas was 19%. One hundred and thirty-three patients (34%) received adjuvant chemotherapy (5-fluorouracil/levamisole) with curative intent. The presence of p53 mutation did not predict for survival in either the treated or untreated groups. The presence of MSI in the proximal/transverse colon carcinoma group was associated with significantly better 5-year survival: 58 versus 32% (p = 0.015, log rank test). This was largely due to better survival observed in the MSI subgroup that received adjuvant chemotherapy (p = 0.017, log rank test). Further work in prospective, randomised clinical trials investigating the effects of adjuvant therapy should consider incorporating MSI status in order to determine whether this is an independent predictive factor for survival and/or response to adjuvant chemotherapy.

Routine analysis of p53 mutation in clinical breast tumor specimens using fluorescence-based polymerase chain reaction and single strand conformation polymorphism

Improved prognostic and predictive markers in breast cancer management would help considerably in therapeutic decision making, particularly in patients with early-stage breast cancer. Tumor factors currently used for prognostication and management decisions are tumor size, histologic type and grade, axillary lymph node status, and estrogen receptor content. The discovery of various somatic genetic alterations in breast cancer has raised the possibility that these may provide additional and independent prognostic and predictive information. Alterations of the p53 tumor suppressor gene in particular have received the most attention as potential prognostic and predictive factors. In multivariate analysis, p53 gene mutation is consistently associated with a two- to threefold increased risk of relapse and death from breast cancer. One of the major reasons preventing the introduction of p53 mutation as a routine marker to assist in therapeutic decision making is the lack of a simple, reproducible, and inexpensive assay. In the present study the authors optimized a polymerase chain reaction-based mutation screening method, fluorescence-single strand conformation polymorphism (F-SSCP), that allows p53 status to be assessed accurately and reproducibly in routinely handled, formalin-fixed and paraffin-embedded tumor specimens. The frequency of p53 mutation observed using F-SSCP in a consecutive series of invasive ductal breast carcinomas was 17% (28/164). The authors propose that the prognostic and predictive values of p53 mutation in breast cancer should be further evaluated in prospective, randomized studies using this standardized technique.

Effect of acute moderate changes in PaCO2 on global hemodynamics and gastric perfusion

OBJECTIVE

To describe global hemodynamics and splanchnic perfusion changes in response to acute modifications in Paco2 in hemodynamically stable patients.

DESIGN

Prospective, randomized crossover study.

SETTING

Medical-surgical intensive care unit at a community hospital (400,000 inhabitants).

PATIENTS

Ten critically ill patients who were sedated, paralyzed, and mechanically ventilated.

INTERVENTIONS

Hypercapnia and hypocapnia were obtained by increasing and reducing instrumental deadspace in random order. After each intervention, patients returned to the basal condition. Each period lasted 80 min: 20 min to achieve stable Paco2 and 60 min for tonometer equilibration. In each period, global hemodynamic variables and tonometric data were collected. The periods were compared using analysis of variance.

MEASUREMENTS AND MAIN RESULTS

Acute hypercapnia (Paco2 from 40+/-3 to 52+/-3 torr, p<.05) increased cardiac index (3.43+/-0.37 vs. 3.97+/-0.43 mL/min/m2, p<.05), heart rate (95+/-6 vs. 105+/-3 beats/min, p<.05), and mean pulmonary artery pressure (21+/-1 vs. 24+/-1 mm Hg, p<.05) and reduced systemic vascular resistance (992+/-98 vs. 813+/-93 dyne x sec/ cm5, p<.05) and oxygen extraction ratio (27+/-3% vs. 22+/-2%, p<.05). Standardized intramucosal Pco2 increased from 49+/-2 to 61+/-3 torr (p<.05) with an associated decrease in calculated intramucosal pH ([pHi] 7.35+/-0.03 vs. 7.25+/-0.02, p<.05), but the gastro-arterial Pco2 gradient (deltaPco2) did not change. Acute hypocapnia (Paco2 from 41+/-3 to 34+/-3 torr, p<.05; pH 7.41+/-0.01 to 7.47+/-0.02, p<.05) induced slight increments in systemic vascular resistance (995+/-117 vs. 1088 +/- 160 dyne x sec/cm5, p<.05) and oxygen extraction ratio (28+/-2% vs. 30+/-2%, p<.05). Standardized intramucosal Pco2 decreased (50+/-4 vs. 44+/-3 torr, p<.05), pHi increased (7.33+/-0.03 vs. 7.36+/-0.02; p<.05), but deltaPco2 did not change.

CONCLUSIONS

In this small group of stable patients, moderate acute variations in Paco2 had a significant effect on global hemodynamics, but splanchnic perfusion, assessed by deltaPco2, did not change. In these conditions, the use of pHi to evaluate gastric perfusion appears unreliable.

A quality assurance audit: phase III trial of maximal androgen deprivation in prostate cancer (TROG 96.01)

In 1997 the Trans-Tasman Radiation Oncology Group (TROG) performed a quality assurance (QA) audit of its phase III randomized clinical trial investigating the effectiveness of different durations of maximal androgen deprivation prior to and during definitive radiation therapy for locally advanced carcinoma of the prostate (TROG 96.01). The audit reviewed a total of 60 cases from 15 centres across Australia and New Zealand. In addition to verification of technical adherence to the protocol, the audit also incorporated a survey of centre planning techniques and a QA time/cost analysis. The present report builds on TROG's first technical audit conducted in 1996 for the phase III accelerated head and neck trial (TROG 91.01) and highlights the significant progress TROG has made in the interim period. The audit provides a strong validation of the results of the 96.01 trial, as well as valuable budgeting and treatment planning information for future trials. Overall improvements were detected in data quality and quantity, and in protocol compliance, with a reduction in the rate of unacceptable protocol violations from 10 to 4%. Audit design, staff education and increased data management resources were identified as the main contributing factors to these improvements. In addition, a budget estimate of $100 per patient has been proposed for conducting similar technical audits. The next major QA project to be undertaken by TROG during the period 1998-1999 is an intercentre dosimetry study. Trial funding and staff education have been targeted as the key major issues essential to the continued success and expansion of TROG's QA programme.

Inhibition of platelet aggregation with a glycoprotein IIb-IIIa antagonist does not prevent thrombin generation in patients undergoing thrombolysis for acute myocardial infarction

Thrombin activity has been implicated as a mechanism for failed reperfusion and reocclusion following thrombolysis. Aggregating platelets provide a phospholipid surface on which prothrombin is cleaved to form thrombin. We examined markers of thrombin generation and activity in patients enrolled in a randomized, placebo-controlled, dose escalating trial of the platelet glycoprotein IIb-IIIa inhibitor eptifibatide (Integrilintrade mark) administered concomitantly with tissue plasminogen activator for the treatment of myocardial infarction. Measurements were obtained at baseline, at 90 minutes, and at 6, 12, and 24 hours after starting therapy. Eptifibatide inhibited platelet aggregation in response to 20 microM ADP. Levels of fibrinopeptide A (FPA), thrombin-antithrombin complexes (TAT), and prothrombin fragment 1.2 (F1.2) were not lower in patients treated with eptifibatide than in the control group. In the course of dose escalation, two groups of patients received the same 135 microg/kg bolus of eptifibatide, one with and one without a heparin bolus. FPA levels were dramatically lower in the heparin-treated patients. Levels of FPA, TAT, and F1.2 were not higher in patients with than in those without recurrent ischemia, or in patients without than in those with Thrombolysis in Myocardial Infarction (TIMI) grade 3 angiographic flow at 90 minutes. These data suggest that thrombin generation and activity persist following thrombolysis, despite inhibition of platelet aggregation, and that treatment with inhibitors of thrombin activity may be required even when glycoprotein IIb-IIIa inhibitors are used.

P53 alterations have no prognostic or predictive significance in Dukes' C rectal carcinomas

We investigated the prognostic significance of p53 alterations in a consecutive series of 122 Dukes' C rectal carcinomas with a median patient follow-up period of 56 months. One third of patients were treated with post-operative adjuvant chemotherapy. Overexpression of p53 protein was observed in 42% (50/118) of cases using immunohistochemical analysis and mutation of the p53 gene in 38% (47/122) using single strand conformation polymorphism technique. Neither p53 overexpression nor mutation were associated with significantly worse patient survival in the overall group or in the subgroup of 35 patients who received standard post-operative chemotherapy with 5-fluorouracil and levamisole. Our results do not support the use of p53 alteration as a clinically useful prognostic marker for the overall survival of rectal cancer patients or for predicting their response to chemotherapy.

TP53 gene mutation status in pretreatment biopsies of oesophageal adenocarcinoma has no prognostic value

Identification of markers which help to predict response to treatment and overall survival at the time of diagnosis would assist in the management of patients with oesophageal adenocarcinoma. In the present study we investigated the prognostic significance of mutations to the TP53 tumour suppressor gene in a large, consecutive series of oesophageal adenocarcinomas. The incidence of TP53 mutation determined by molecular analysis of endoscopic biopsy specimens was 36% (49/135). No statistically significant difference was observed in patient survival according to the TP53 status of the tumour biopsy. The median survival time for patients with mutation was 12 +/- 1 months compared with 14 +/- 2 months for patients with TP53. These results demonstrate that mutation of the TP53 gene is not a useful predictive marker for patient survival in oesophageal adenocarcinoma.