Novel partial reduction of the humanized anti-cocaine mAb h2E2 for selective cysteine labeling.

Monoclonal antibodies are utilized for treating many diseases and disorders, as well as for basic research and development. Covalent labeling of mAbs is important for various antibody applications and creating antibody drug conjugates. Labeling at reactive lysine residues using lysine selective reagents is useful, but is non-selective and can interfere with antigen binding and interactions of the Fc antibody region. In this work, using an anti-cocaine mAb (h2E2), we utilized triphenylphosphine-3,3',3″-trisulfonic acid (TPPTS), and demonstrated for the first time reduction of disulfides in an antibody by TPPTS. More importantly, this reduction was very reproducible, limited, and selective, and permitted selective labeling of the antibody with a cysteine reactive fluorescent reagent, resulting in labeling of a few specific cysteines. Similar results were obtained using TCEP-agarose reduction. We demonstrated that both of these selective partial reduction methods gave rise to approximately two labels per mAb, mostly by selective reduction of the heavy chain to light chain disulfide bond, as demonstrated by non-reducing SDS-PAGE protein band analysis. Thus, convenient, reproducible, and selective mAb disulfide reduction was achieved under mild conditions. These labeled, partially reduced mAbs were characterized by differential scanning fluorimetry (DSF), detecting the incorporated fluorescein instead of an exogenously added dye, and for antigen (cocaine) binding by isothermal titration calorimetry (ITC). Both the structure and antigen binding of the mAb was maintained. This novel selective reduction and labeling is generally relevant to modification of antibodies and to future development of conjugated mAbs for experimental and therapeutic purposes.

Clinical utility of reticulocyte haemoglobin in the assessment of iron deficiency and iron deficiency anaemia in the paediatric population.

AIM: Reticulocyte haemoglobin (Ret-He) is a useful marker in the assessment of iron stores in adult and paediatric patients. It is currently not utilised in Pathology Queensland. The objective of this study is to verify Ret-He in our Pathology Queensland laboratory and assess the clinical utility in the assessment of iron deficiency (ID) and iron deficiency anaemia (IDA) in paediatric patients. METHODS: Samples from patients aged <18 years sent to the Pathology Queensland laboratory that had paired full blood count and iron studies were included in this study. A minimum of 120 samples were required for verification of testing requirements and a minimum of 30 samples per age range were required for confirmation of published age-related reference intervals. RESULTS: Published Ret-He reference intervals were confirmed for stated age ranges in normal (non-ID) patients. Ret-He below the reference range for age demonstrated a good correlation with ID and IDA. CONCLUSIONS: Ret-He is a useful marker in the assessment of ID and IDA in a paediatric population. It is not affected by acute or chronic inflammation. Ret-He is sensitive and specific (86% and 92%) for the diagnosis of ID.

The compulsion zone explains the self-administration of cocaine, RTI-55 and bupropion in rats.

Rats that reliably self-administered cocaine also reliably self-administered the cocaine analog RTI-55 and bupropion. The inter-injection intervals of these dopamine transporter (DAT) inhibitors were regular at a given unit dose and increased as a function of unit dose. However, the mean rate of intake differed widely, ranging from 731 to 459 to 2.1 nmol/kg∙min-1 for bupropion, cocaine and RTI-55 respectively, a dramatic 348-fold range. An analysis of inter-injection intervals as a function of unit dose generated values for the mean satiety threshold of 50.6, 5.1 and 0.7 nmol/kg and t1/2 of 56.7, 9.3 and 255.6 min for bupropion, cocaine and RTI-55, respectively. The difference in rate of intake of bupropion and RTI-55 relative to cocaine is a product of their 0.1 and 7.3 fold difference in PD potency and their 6.1 and 27.5 fold difference in t1/2. Additionally, the relative durations of lever-pressing following termination of drug access correlated with the t1/2 estimates. It is hypothesized this duration represents the time required for the drug concentration to fall from the satiety threshold below the priming threshold (the minimum DAT inhibitor level that will induce lever-pressing). This indicates that the time needed for an animal to cease lever pressing following termination of access to the DAT inhibitor is predominately a function of the PK properties of the agonist. The self-administration behavior paradigm in the context of the compulsion zone theory can be used as a bioassay to determine the PK/PD properties of indirect dopamine receptor agonists.

Multi-domain unfolding of the Fab fragment of a humanized anti-cocaine mAb characterized by non-reducing SDS-PAGE.

Monoclonal antibodies and their fragments are widely used for research and therapy. Fab fragments are useful since they retain antigen binding specificity, but being smaller proteins, are better able to penetrate biological compartments and tumors, and do not induce Fc-dependent immunological system activation. Our laboratory developed an anti-cocaine mAb (named h2E2) for the treatment of cocaine use disorders, which is currently in advanced pre-clinical development. We are also interested in the Fab fragment of this mAb for potential therapy of acute cocaine overdose. Previously, we showed that this mAb and its F(ab')2 and Fab fragments undergo discrete domain unfolding, as detected by non-reducing SDS-PAGE, and that ligand-induced protein thermal stabilization can be quantitated utilizing differential scanning fluorimetry in the absence of SDS. Here, we demonstrate that multiple Fab protein gel bands observed using non-reducing SDS-PAGE in the presence and absence of cocaine and its metabolites can be explained and interpreted based on the differential stabilization of two unfolding domains in the Fab fragment. The variable domain is stabilized by ligands against SDS unfolding, while the constant domain is not. This data and its interpretation are also supported by differential scanning fluorimetry data for the Fab fragment in SDS. It is likely that these non-reducing SDS-PAGE results and the gel band domain unfolding model will be applicable to other small molecule binding antibodies. Thus, non-reducing SDS-PAGE is a widely available and simple method for assessing domain stability and multi-step unfolding of Fab fragments.

A novel de novo ACTA1 variant in a patient with nemaline myopathy and mitochondrial Complex I deficiency.

We describe the presentation and follow-up of a three-year-old girl with nemaline myopathy due to a de-novo variant in ACTA1 (encoding skeletal alpha actin) and moderately low enzyme level of Complex I of the mitochondrial respiratory chain. She presented in the neonatal period with hypotonia, followed by weakness in the facial, bulbar, respiratory and neck flexors muscles. A biopsy of her quadriceps muscle at the age of one year showed nemaline rods. Based on her clinical presentation of a congenital myopathy and histopathological features on a muscle biopsy, ACTA1 was sequenced, and this revealed a novel sequence variant, c.760 A>C p. (Asn254His). In addition, mitochondrial respiratory chain enzymatic activity of skeletal muscle biopsy showed a moderately low activity of complex I (nicotinamide adenine dinucleotide (NADH): ubiquinone oxidoreductase). Disturbances of Complex I of the respiratory chain have been reported in patients with nemaline myopathy, although the mechanism remains unclear.

Loss of tubulin deglutamylase CCP1 causes infantile-onset neurodegeneration.

A set of glutamylases and deglutamylases controls levels of tubulin polyglutamylation, a prominent post-translational modification of neuronal microtubules. Defective tubulin polyglutamylation was first linked to neurodegeneration in the Purkinje cell degeneration (pcd) mouse, which lacks deglutamylase CCP1, displays massive cerebellar atrophy, and accumulates abnormally glutamylated tubulin in degenerating neurons. We found biallelic rare and damaging variants in the gene encoding CCP1 in 13 individuals with infantile-onset neurodegeneration and confirmed the absence of functional CCP1 along with dysregulated tubulin polyglutamylation. The human disease mainly affected the cerebellum, spinal motor neurons, and peripheral nerves. We also demonstrate previously unrecognized peripheral nerve and spinal motor neuron degeneration in pcd mice, which thus recapitulated key features of the human disease. Our findings link human neurodegeneration to tubulin polyglutamylation, entailing this post-translational modification as a potential target for drug development for neurodegenerative disorders.

Selective disulfide reduction for labeling and enhancement of Fab antibody fragments.

Many methods have been developed for chemical labeling and enhancement of the properties of antibodies and their common fragments, including the Fab and F(ab')2 fragments. Somewhat selective reduction of some antibody disulfide bonds has been previously achieved, yielding antibodies and antibody fragments that can be labeled at defined sites, enhancing their utility and properties. Selective reduction of the two hinge disulfide bonds present in F(ab')2 fragments using mild reduction has been useful. However, such reduction is often not quantitative and results in the reduction of multiple disulfide bonds, and therefore subsequent multiple labeling or conjugation sites are neither homogenous nor stoichiometric. Here, a simple and efficient selective reduction of the single disulfide bond linking the partial heavy chain and the intact light chain which compose the Fab fragment is accomplished utilizing tris(2-carboxyethyl)phosphine (TCEP) immobilized on agarose beads. The resultant reduced cysteine residues were labeled with several cysteine-selective fluorescent reagents, as well as by cysteine-directed PEGylation. These two cysteine residues can also be re-ligated by means of a bifunctional cysteine cross-linking agent, dibromobimane, thereby both restoring a covalent linkage between the heavy and light chains at this site, far removed from the antigen binding site, and also introducing a fluorescent probe. There are many other research and clinical uses for these selectively partially reduced Fab fragments, including biotinylation, toxin and drug conjugation, and incorporation of radioisotopes, and this technique enables simple generation of very useful Fab fragment derivatives with many potential applications.

Use of raw glycerol to produce oil rich in polyunsaturated fatty acids by a thraustochytrid.

Glucose is the typical carbon source for producing microbial polyunsaturated fatty acids (PUFA) with single cell microorganisms such as thraustochytrids. We assessed the use of a fish oil derived glycerol by-product (raw glycerol), produced by a fish oil processing plant, as a carbon source to produce single cell oil rich in polyunsaturated fatty acids (PUFA), notably docosahexaenoic acid (DHA). These results were compared to those obtained when using analytical grade glycerol, and glucose. The thraustochytrid strain tested produced similar amounts of oil and PUFA when grown with both types of glycerol, and results were also similar to those obtained using glucose. After 6 days of fermentation, approximately 320 mg/g of oil, and 145 mg/g of PUFA were produced with all carbon sources tested. All oils produced by our strain were 99.95% in the triacylglycerol form. To date, this is the first report of using raw glycerol derived from fish oil for producing microbial triglyceride oil rich in PUFA.

Correlation of overall survival with gene expression profiles in a prospective study of resectable esophageal cancer.

PURPOSE: Preoperative chemotherapy has demonstrated a survival benefit for patients with potentially resectable esophageal cancer; however, currently it is not possible to predict the benefit of this treatment for an individual patient. This prospective study was designed to correlate gene expression profiles with clinical outcome in this setting. PATIENTS AND METHODS: Eligible patients were deemed to have resectable disease after staging by computed tomography, endoscopic ultrasound, and laparoscopy as indicated and following discussion at the multidisciplinary team meeting. All patients received neoadjuvant platinum and fluoropyrimidine-based chemotherapy; and clinical data were entered prospectively onto a study-specific database. Total RNA was isolated from pretreatment tumor biopsies obtained at baseline endoscopy and analyzed using a cDNA array consisting of 22,000 cDNA clones. RESULTS: Of the patients with adequate follow-up accrued between 2002 and 2005, 35 satisfied the quality control measures for the microarray profiling. Median follow-up was 938 days. Supervised hierarchical clustering of normalized data revealed 165 significantly differentially expressed genes based on overall survival (OS; P < .01) with 2 distinct clusters: a poor outcome group: N = 17 (1 year OS 46.2%) and a good outcome group: N = 18 (1 year OS 100%). Genes identified included those previously associated with esophageal cancer and, interestingly, a group of genes encoding proteins involved in the regulation of the TOLL receptor-signaling pathway. CONCLUSION: This initial study has highlighted groups of tumors with distinct gene expression profiles based on survival and warrants further validation in a larger cohort. This approach may further our understanding of individual tumor biology and thus facilitate the development of tailored treatment.

Thromboembolism in patients with advanced gastroesophageal cancer treated with anthracycline, platinum, and fluoropyrimidine combination chemotherapy: a report from the UK National Cancer Research Institute Upper Gastrointestinal Clinical Studies Group.

PURPOSE: Data concerning the prevalence of and outcomes related to thromboembolic events (TEs) in patients with advanced gastroesophageal cancer who are undergoing chemotherapy are limited. PATIENTS AND METHODS: This was a prospective, exploratory analysis of TEs in a randomized, controlled trial of 964 patients recruited between 2000 and 2005 and treated with epirubicin/platinum/fluoropyrimidine combination chemotherapy for advanced/locally advanced gastroesophageal cancer. Regimens were epirubicin (E), cisplatin (C), fluorouracil (F; ECF); E, C, capecitabine (X; ECX); E, F, oxaliplatin (O; EOF); and EOX. Continuously infused F was administered via a central venous access device (CVAD) with 1 mg of warfarin for thromboprophylaxis. The principal outcome was the incidence of TEs (venous and arterial) in the whole treated patient cohort, according to chemotherapy, associated with CVADs and TE-related prognoses. RESULTS: The incidences of any, of venous, and of arterial TEs among 964 treated patients were 12.1% (95% CI, 10.7 to 14.3), 10.1% (95% CI, 8.3 to 12.3), and 2.2% (95% CI, 1.4 to 3.4) respectively. There were fewer TEs in the O compared with the cisplatin groups (EOF/EOX v ECF/ECX: 7.6% v 15.1%; P = .0003). C was identified as a risk factor for TE in multivariate analysis (hazard ratio [HR], 0.51; 95% CI, 0.34 to 0.76; P = .001). There was no difference in the incidence of TEs for the F group compared with the capecitabine groups. The incidence of CVAD-related thrombosis was 7.0% (ECF/EOF arms). Overall survival was worse for patients who experienced TEs versus no TEs (median survival, 7.4 v 10.5 months; HR, 0.8; 95% CI, 0.64 to 0.99; P = .043). CONCLUSION: This analysis has prospectively quantified the incidence/pattern of TEs among patients with advanced gastroesophageal cancer who were treated with four triplet regimens, has demonstrated a differential thrombogenic effect according to platinum use, and has noted a poorer outcome associated with TE during treatment. Chemotherapy-related TE should contribute to the risk/benefit assessment of treatment.

"BRCAness" syndrome in ovarian cancer: a case-control study describing the clinical features and outcome of patients with epithelial ovarian cancer associated with BRCA1 and BRCA2 mutations.

PURPOSE: We evaluated the clinical impact of germ-line BRCA1/2 mutations in patients with epithelial ovarian cancer (EOC) on responses to first and subsequent lines of chemotherapy, treatment-free interval (TFI) between each line of therapy, and overall survival (OS). PATIENTS AND METHODS: Twenty-two EOC patients with germ-line BRCA1 or BRCA2 mutations (BRCA-positive) were selected from our database and matched (1:2) with 44 nonhereditary EOC controls (defined by no associated personal history of breast cancer and no family history of breast and ovarian cancer or an uninformative BRCA mutation test) for stage, histologic subtype, age, and year of diagnosis. All patients received primary platinum-based chemotherapy. Statistical comparisons included responses after first-, second-, and third-line treatment (chi(2)/Fisher's exact test) and median OS (Kaplan-Meier method/log-rank test). RESULTS: Compared with controls, BRCA-positive patients had higher overall (95.5% v 59.1%; P = .002) and complete response rates (81.8% v 43.2%; P = .004) to first line treatment, higher responses to second and third line platinum-based chemotherapy (second line, 91.7% v 40.9% [P = .004]; third line, 100% v 14.3% [P = .005]) and longer TFIs. A significant improvement in median OS in BRCA-positive patients compared with controls was observed from both time of diagnosis (8.4 v 2.9 years; P < .002) and time of first relapse (5 v 1.6 years; P < .001). BRCA status, stage, and length of first response were independent prognostic factors from time of first relapse. CONCLUSION: BRCA-positive EOC patients have better outcomes than nonhereditary EOC patients. There exists a clinical syndrome of BRCAness that includes serous histology, high response rates to first and subsequent lines of platinum-based treatment, longer TFIs between relapses, and improved OS.

Efficacy of palliative low-dose involved-field radiation therapy in advanced lymphoma: a phase II study.

PURPOSE: To confirm the efficacy of low-dose involved-field radiation therapy (LD-IFRT) as palliative treatment in patients symptomatic from advanced lymphoma. PATIENTS AND METHODS: A total of 36 patients (47 sites), received 4 Gy in 2 fractions to the lymphoma with a 1.5-2-cm margin. Pathology subtypes included 29 (62%) sites with indolent lymphoma and 18 (36%) sites with aggressive lymphoma histology. Bulky disease was seen in 22 (48%) sites and, of these, 6 sites had disease > 10 cm. A median of 3 previous chemotherapy regimens (range, 0 to 9 regimens) preceded LD-IFRT. The primary endpoint of the study was in-field lymphoma control. Patients completed the European Organization for the Research and Treatment of Cancer QLQ-C30 quality of life (QOL) questionnaire before RT and at 3-4 weeks after treatment. RESULTS: The overall response rate (RR) at 1-3 months after the RT was 75%. A complete remission (CR) was observed in 13 patients (36%) lasting up to a maximum of 31.3 months and ongoing at analysis. A partial remission (PR) was achieved in 14 patients (39%) lasting up to 10 months. The response rate for non-diffuse large B-cell lymphoma (DLBCL) sites was 86%, while it was 50% for sites with DLBCL histology. Median time to local progression for the entire group was 15 months. There was no statistical difference between the QOL before and after LD-IFRT. CONCLUSION: LD-IFRT is an effective and easy treatment for patients with advanced lymphoma that can be repeated at previously irradiated sites, a particularly useful attribute because of the relapsing nature, especially of advanced follicular subtypes.

Intrinsic markers of tumour hypoxia and angiogenesis in localised prostate cancer and outcome of radical treatment: a retrospective analysis of two randomised radiotherapy trials and one surgical cohort study.

BACKGROUND: Expression of intrinsic markers of tumour hypoxia and angiogenesis are important predictors of radiotherapeutic, and possibly surgical, outcome in several cancers. Extent of tumour hypoxia in localised prostate cancer is comparable to that in other cancers, but few data exist on the association of extent of tumour hypoxia with treatment outcome. We aimed to study the predictive value of intrinsic markers of tumour hypoxia and angiogenesis in localised prostate cancer, both in patients treated with radiotherapy and in those treated surgically. METHODS: We applied a new, needle biopsy tissue microarray (TMA) technique to study diagnostic samples from men with localised, previously untreated prostate cancer treated in two randomised controlled trials of radiotherapy-dose escalation. Multivariate analysis by Cox proportional hazards was done to assess the association between clinical outcome, in terms of biochemical control, and immunohistochemical staining of hypoxia inducible factor-1 alpha (HIF-1 alpha), vascular endothelial growth factor (VEGF), and osteopontin expression. The analysis was repeated on an independent series of men with localised, previously untreated prostate cancer treated by radical prostatectomy. The main outcome was time to biochemical (ie, prostate-specific antigen [PSA]) failure. FINDINGS: Between Oct 12, 1995, and Feb 5, 2002, 308 patients were identified from two prospective, randomised trials at the Royal Marsden Hospital, London and Sutton, UK, for the radiotherapy cohort and diagnostic biopsies were available for 201 of these patients. Between June 6, 1995, and Nov 4, 2005, 329 patients were identified from the Aarhus University Hospital, Skejby, Denmark, for the prostatectomy cohort; of these, 40 patients were excluded because the tumour was too small to sample (19 patients), because the paraffin block was too thin (19 patients), or because the blocks were missing (two patients), leaving 289 patients for analysis. For patients treated with radiotherapy, increased staining for VEGF (p=0.008) and HIF-1 alpha (p=0.02) expression, but not increased osteopontin expression (p=0.978), were significant predictors of a shorter time to biochemical failure on multivariate analysis, independent of clinical tumour stage, Gleason score, serum PSA concentration, and dose of radiotherapy. For patients treated with surgery, increased staining for VEGF (p<0.0001) and HIF-1 alpha (p<0.0001) expression, and increased osteopontin expression (p=0.0005) were each significantly associated with a shorter time to biochemical failure on multivariate analysis, independent of pathological tumour stage, Gleason score, serum PSA concentration, and margin status. INTERPRETATION: To our knowledge, this is the largest study of intrinsic markers of hypoxia and angiogenesis in relation to the outcome of radical treatment of localised prostate cancer. Increased expression of VEGF, HIF-1 alpha, and, for patients treated with surgery, osteopontin, identifies patients at high risk of biochemical failure who would be suitable for enrolment into trials of treatment intensification.

Predicting the probability of deferred radical treatment for localised prostate cancer managed by active surveillance.

OBJECTIVES: Outcome data from a prospective study of active surveillance of localised prostate cancer were analysed to identify factors, present at the time of diagnosis, that predict subsequent radical treatment. METHODS: Eligible patients had clinical stage T1-T2a, N0-Nx, M0-Mx adenocarcinoma of the prostate with serum PSA<15 ng/ml, Gleason score 1 ng/ml/yr) or histological progression (primary Gleason grade >or= 4, or %pbc > 50%). Multivariate Cox regression analysis of baseline variables was performed with respect to time to radical treatment. RESULTS: The 326 men recruited from 2002 to 2006 have been followed for a median of 22 mo. Median age was 67 yr, and median initial PSA (iPSA) 6.4 ng/ml. Sixty-five patients (20%) had deferred radical treatment, 16 (5%) changed to watchful waiting because of increasing comorbidity, 7 (2%) died of other causes, and 238 (73%) remain on surveillance. On multivariate Cox regression analysis, the free/total PSA ratio (p<0.001) and clinical T stage (p=0.006) were independent determinants of time to radical treatment. CONCLUSIONS: In addition to established prognostic factors, the free/total PSA ratio may predict time to radical treatment in patients with untreated, localised prostate cancer managed by active surveillance. This possibility warrants further study.

Clinical implications of introducing a new PSA assay.

BACKGROUND: A number of different prostate-specific antigen (PSA) assays are in common use. There has been little consideration of the possible clinical implications of interassay variation. The availability of two assays in the same laboratory provided an opportunity to audit the clinical implications of the interassay variation in PSA levels. METHODS: The same serum samples from patients with prostate cancer on follow-up were analyzed for PSA by the Abbott AxSYM assay and by the Abbott ARCHITECT assays. To assess within-patient reproducibility of the interassay variation, repeat analysis of PSA by both assays was conducted in a second sample obtained at least 1 month after the first. RESULTS: Samples from 156 cases were analyzed. The mean ratio of serum PSA values by the two assays (AxSYM assay/ARCHITECT assay) was 0.89 (range 0.5-2.27). The interassay coefficient of variation was 20%. In a subgroup of 50 cases with repeat samples available, the correlation coefficient, r, of the interassay variation in PSA between the first and second samples was 0.441. CONCLUSIONS: Interassay variation in serum PSA is clinically significant, both between patients and on repeated measurement within the same patient. Clinicians should be aware that simple correction factors may not accurately control for variation between PSA assays. Ideally, patients on follow-up for prostate cancer should be monitored using a single PSA assay.

Capecitabine and oxaliplatin for advanced esophagogastric cancer.

BACKGROUND: We evaluated capecitabine (an oral fluoropyrimidine) and oxaliplatin (a platinum compound) as alternatives to infused fluorouracil and cisplatin, respectively, for untreated advanced esophagogastric cancer. METHODS: In a two-by-two design, we randomly assigned 1002 patients to receive triplet therapy with epirubicin and cisplatin plus either fluorouracil (ECF) or capecitabine (ECX) or triplet therapy with epirubicin and oxaliplatin plus either fluorouracil (EOF) or capecitabine (EOX). The primary end point was noninferiority in overall survival for the triplet therapies containing capecitabine as compared with fluorouracil and for those containing oxaliplatin as compared with cisplatin. RESULTS: For the capecitabine-fluorouracil comparison, the hazard ratio for death in the capecitabine group was 0.86 (95% confidence interval [CI], 0.80 to 0.99); for the oxaliplatin-cisplatin comparison, the hazard ratio for the oxaliplatin group was 0.92 (95% CI, 0.80 to 1.10). The upper limit of the confidence intervals for both hazard ratios excluded the predefined noninferiority margin of 1.23. Median survival times in the ECF, ECX, EOF, and EOX groups were 9.9 months, 9.9 months, 9.3 months, and 11.2 months, respectively; survival rates at 1 year were 37.7%, 40.8%, 40.4%, and 46.8%, respectively. In the secondary analysis, overall survival was longer with EOX than with ECF, with a hazard ratio for death of 0.80 in the EOX group (95% CI, 0.66 to 0.97; P=0.02). Progression-free survival and response rates did not differ significantly among the regimens. Toxic effects of capecitabine and fluorouracil were similar. As compared with cisplatin, oxaliplatin was associated with lower incidences of grade 3 or 4 neutropenia, alopecia, renal toxicity, and thromboembolism but with slightly higher incidences of grade 3 or 4 diarrhea and neuropathy. CONCLUSIONS: Capecitabine and oxaliplatin are as effective as fluorouracil and cisplatin, respectively, in patients with previously untreated esophagogastric cancer. (Current Controlled Trials number, ISRCTN51678883 [controlled-trials.com].).

A comparison of the use of bony anatomy and internal markers for offline verification and an evaluation of the potential benefit of online and offline verification protocols for prostate radiotherapy.

PURPOSE: To evaluate the utility of intraprostatic markers in the treatment verification of prostate cancer radiotherapy. Specific aims were: to compare the effectiveness of offline correction protocols, either using gold markers or bony anatomy; to estimate the potential benefit of online correction protocol's using gold markers; to determine the presence and effect of intrafraction motion. METHODS AND MATERIALS: Thirty patients with three gold markers inserted had pretreatment and posttreatment images acquired and were treated using an offline correction protocol and gold markers. Retrospectively, an offline protocol was applied using bony anatomy and an online protocol using gold markers. RESULTS: The systematic errors were reduced from 1.3, 1.9, and 2.5 mm to 1.1, 1.1, and 1.5 mm in the right-left (RL), superoinferior (SI), and anteroposterior (AP) directions, respectively, using the offline correction protocol and gold markers instead of bony anatomy. The subsequent decrease in margins was 1.7, 3.3, and 4 mm in the RL, SI, and AP directions, respectively. An offline correction protocol combined with an online correction protocol in the first four fractions reduced random errors further to 0.9, 1.1, and 1.0 mm in the RL, SI, and AP directions, respectively. A daily online protocol reduced all errors to <1 mm. Intrafraction motion had greater impact on the effectiveness of the online protocol than the offline protocols. CONCLUSIONS: An offline protocol using gold markers is effective in reducing the systematic error. The value of online protocols is reduced by intrafraction motion.

Prostate-specific antigen velocity in untreated, localized prostate cancer.

OBJECTIVE: To report the results of a prospective study of active surveillance of untreated prostate cancer, with a focus on baseline predictors of prostate-specific antigen (PSA) velocity, as PSA velocity before treatment is an important predictor of prostate cancer mortality, and patients on active surveillance are monitored for several years to estimate the PSA velocity and thus select patients for radical treatment. PATIENTS AND METHODS: A prospective study of active surveillance for localized prostate cancer opened at the Royal Marsden Hospital in 2002. Eligible patients had clinical stage T1/T2a, N0/Nx, M0/Mx adenocarcinoma of the prostate with a serum PSA level of < 15 ng/mL, a Gleason score of < or = 7 with primary grade < or = 3, and less than half the biopsy cores positive. The PSA velocity before treatment was analysed in relation to baseline clinical characteristics. RESULTS: In all, 237 patients on surveillance were followed for a median of 24 months (median age 67 years; median initial PSA level 6.5 ng/mL; median pretreatment PSA velocity 0.44 ng/mL per year). On multivariate analysis, PSA density (i.e. serum PSA level/prostate volume) was the only significant determinant of PSA velocity (P < 0.001). Patients with a PSA density above or below the median (0.185 ng/mL/mL) had a median (interquartile range) PSA velocity of 0.92 (0.34-1.77) ng/mL per year and 0.35 (-0.06, 0.80) ng/mL per year, respectively. CONCLUSIONS: PSA density, which is readily available at the time of diagnosis, is an independent determinant of PSA velocity in untreated, localized prostate cancer. If this is confirmed, PSA density could be used to inform the often difficult choice between active surveillance and immediate radical treatment.

Predictors of histological disease progression in untreated, localized prostate cancer.

PURPOSE: Active surveillance for early prostate cancer is a policy of close monitoring with radical treatment targeted at cases with evidence of disease progression. There is no consensus on the need for or optimum timing of repeat biopsies as part of active surveillance. MATERIALS AND METHODS: In a prospective cohort study of active surveillance 119 patients with untreated localized prostate cancer (T1/2a), prostate specific antigen less than 15 ng/ml, Gleason score 3 + 4 or less and 50% or less positive cores underwent repeat biopsy after 18 to 24 months. Histological disease progression was defined as primary Gleason grade 4 or greater, greater than 50% positive cores or a Gleason score increase from 6 or less to 7 or greater. The risk of histological disease progression was analyzed with respect to baseline clinical factors. RESULTS: Median patient age was 66 years and median initial prostate specific antigen was 6.6 ng/ml. Histological disease progression was seen in 33 of 119 cases (28%). On multivariate analysis prostate specific antigen density (p = 0.002) and maximum percent involvement of any core (p = 0.04) were significant independent determinants of histological disease progression. Progression was seen in 22 of 40 cases (55%) with prostate specific antigen density 0.2 ng/ml/ml or greater and greater than 15% maximum involvement of any core. Progression was seen in 2 of 33 cases (6%) with prostate specific antigen density less than 0.2 ng/ml/ml and 15% or less maximum involvement of any core. CONCLUSIONS: Repeat biopsy should be an integral part of active surveillance for untreated localized prostate cancer. Immediate repeat biopsy should be considered in patients who elect active surveillance but who have prostate specific antigen density greater than 0.2 ng/ml/ml. These findings must be validated in a cohort of patients with extended biopsies at diagnosis and followup.

Long-term effects of a short course of neoadjuvant luteinizing hormone-releasing hormone analogue and radical radiotherapy on the hormonal profile in patients with localized prostate cancer.

OBJECTIVE: To assess whether a long-term follow-up shows any reduction in the level of luteinizing hormone (LH) secretion, which could result in declining testosterone levels in men with localized prostate cancer, as most (96%) men have testosterone levels within the normal range by 1 year after treatment with a short course of LH-releasing hormone analogue (LHRHa) and radiotherapy, and LH and follicle stimulating hormone (FSH) remain high at 1 year after treatment, maintaining the testosterone levels. PATIENTS AND METHODS: We prospectively evaluated 55 patients who previously had a short course of LHRHa (median 97 days, range 28-167) and radiotherapy for localized prostate cancer. Eligible patients had documented normal testosterone, LH and FSH levels at baseline and at 1-3 years after radiotherapy. LH, FSH and testosterone were then measured at 5 years after treatment. RESULTS: The mean hormone levels before, at 1-3 years and at 5 years after treatment, respectively, were: testosterone (nmol/L), 15.33, 13.98, 12.97; LH (U/L), 5.51, 9.95, 6.95; and FSH (U/L), 7.95, 22.40, 17.00. The decrease in testosterone level at 5 years vs 1-3 years was not statistically significant and was of little clinical relevance (P = 0.057). LH and FSH levels were higher at 1-3 years than at baseline and decreased significantly (P < 0.001) at 5 years towards the baseline value. The decrease in FSH level was less marked than for LH. CONCLUSION: After a short course of LHRHa and radiotherapy, the testosterone level was maintained at 5 years. LH levels decreased towards the baseline value, suggesting recovery of Leydig cell function. FSH levels remained high, suggesting persistent Sertoli cell damage from treatment.