Malignant mesotheliomas in former miners and millers of crocidolite at Wittenoom (Western Australia) after more than 50 years follow-up

Background:

To report the number of malignant pleural and peritoneal mesotheliomas that have occurred in former Wittenoom crocidolite workers to the end of 2008, to compare this with earlier predictions, and to relate the mesothelioma rate to amount of exposure.

Methods:

A group of 6489 men and 419 women who had worked for the company operating the former Wittenoom crocidolite mine and mill at some time between 1943 and 1966 have been followed up throughout Australia and Italy to the end of 2008.

Results:

The cumulative number of mesotheliomas up to 2008 was 316 in men (268 pleural, 48 peritoneal) and 13 (all pleural) in women. There had been 302 deaths with mesothelioma in men and 13 in women, which was almost 10% of all known deaths. Mesothelioma rate, both pleural and peritoneal, increased with time since first exposure and appeared to reach a plateau after about 40 to 50 years. The mesothelioma rate increased with amount of exposure and the peritoneal mesotheliomas occurred preferentially in the highest exposure group, 37% compared with 15% overall.

Conclusion:

By the end of 2008, the number of mesothelioma deaths had reached 4.7% for all the male workers and 3.1% for the females. Over the past 8 years the numbers were higher than expected. It is predicted that about another 60 to 70 deaths with mesothelioma may occur in men by 2020.

Primary rectal melanoma

Primary rectal melanoma is rare and only represents up to 4% of anorectal malignancies. The prognosis of such a diagnosis is significantly different to a metastatic melanoma deposit in the anorectal area and therefore differentiation between the two is of the utmost importance with regards to initial treatment and long-term management. Various immunohistochemical markers have been shown to be associated with primary melanoma and strongly aid in diagnosis. Surgical management is still widely disputed and multiple papers have been published comparing wide local excision with abdominoperineal resection. Here a case of primary rectal melanoma is presented with a brief discussion exploring diagnostic techniques, treatment options and prognostic factors.

Risk of childhood acute lymphoblastic leukaemia following parental occupational exposure to extremely low frequency electromagnetic fields

Background:

Earlier studies have reported moderate increases in the risk of acute lymphoblastic leukaemia (ALL) among children whose mothers have been occupationally exposed to extremely low frequency (ELF) electromagnetic fields. Other studies examining parental occupational exposure to ELF and ALL have reported mixed results.

Methods:

In an Australian case–control study of ALL in children aged <15 years, parents were asked about tasks they undertook in each job. Exposure variables were created for any occupational exposure before the birth of the child, in jobs 2 years before birth, in jobs 1 year before birth and up to 1 year after birth.

Results:

In all, 379 case and 854 control mothers and 328 case and 748 control fathers completed an occupational history. Exposure to ELF in all time periods was similar in case and control mothers. There was no difference in exposure between case and control fathers. There was no association between maternal (odds ratio (OR)=0.96; 95% CI=0.74–1.25) or paternal (OR=0.78; 95% CI=0.56–1.09) exposure to ELF any time before the birth and risk of childhood ALL.

Conclusion:

We did not find an increased risk of ALL in offspring of parents with occupational exposure to ELF.

A health and safety survey of Irish funeral industry workers

BACKGROUND

Those handling deceased individuals, including the funeral industry, face a variety of health and safety hazards including occupationally acquired infectious disease.

AIMS

To identify the knowledge, attitudes and beliefs of Irish funeral industry workers towards occupational hazards and infectious disease in 2009.

METHODS

The sample analysed consisted of all listed member premises of the Irish Association of Funeral Directors as at 1 July 2009. A postal survey was sent to each premises in July 2009, with two rounds of follow-up reviews sent to non-responders. Four main areas were covered--occupational hazards, embalming, industry expertise and demographics. The quantitative and qualitative results were analysed to assess knowledge, attitudes and beliefs. Data collection was completed on 31 December 2009.

RESULTS

Two hundred and thirty listed member premises were contacted. Twenty-two were unsuitable for the survey. One hundred and thirty-eight valid replies were received from 130 premises, representing a premises response rate of 63% (130/208). Seventy-three premises (56%) identified themselves as embalmers. Embalmers had variable vaccine uptake and variable knowledge, attitude and beliefs towards embalming those with blood-borne viruses. Fifteen per cent of respondents reported a work-related injury, back injury being the most common. Splash and sharps injuries were reported as a work-related injury, and infections believed to be work related were also reported.

CONCLUSIONS

This study demonstrates widespread occupational health concerns among this professional group. It confirms the need for occupational health advice and services. There is also a strong desire for regulation of this profession in Ireland.

Nonsurgical correction of congenital ear abnormalities in the newborn: Case series

OBJECTIVE

To determine whether a simple, nonsurgical treatment for congenital ear abnormalities (lop-ear, Stahl's ear, protruding ear, cryptotia) improved the appearance of ear abnormalities in newborns at six weeks of age.

METHODS

This is a descriptive case series. All newborns with identified abnormalities were referred by their family physician to one paediatrician (WGS) in a small level 2 perinatal centre. The ears were waxed and taped in a standard manner within 10 days of birth. Pictures were taken before taping and at the end of taping (one month). All patients and pictures were assessed by one plastic surgeon (JWT) at six weeks of age and scored using a standard scoring system. A telephone survey of the nontreatment group was conducted.

RESULTS

The total number of ears assessed was 90. Of this total, 69 ears were taped and fully evaluated in the study (77%). The refusal rate was 23%. In the treatment group, 59% had lop-ear, 19% had Stahl's ear, 17% had protruding ear and 3% had cryptotia. Overall correction (excellent/improved) for the treatment group was 90% (100% for lop-ear, 100% for Stahl's ear, 67% for protruding ear and 0% for cryptotia). In the nontreatment (refusal) group, 67% of the ears failed to correct spontaneously. No complications were recognized by the authors or parents by six weeks. The percentage of newborns in one year in the perinatal centre with recognized ear abnormalities was 6% (90 of 1600).

CONCLUSIONS

A simple, nonsurgical treatment in a Caucasian population appeared to be very effective in correcting congenital ear abnormalities with no complications and high patient/parent satisfaction.

Predicting survival in malignant mesothelioma

Malignant mesothelioma (MM) of the pleura or peritoneum is a universally fatal disease attracting an increasing range of medical interventions and escalating healthcare costs. Changes in survival and the factors affecting survival of all patients ever diagnosed with MM in Western Australia over the past five decades and confirmed by the Western Australian Mesothelioma Registry to December 2005 were examined. Sex, age, date and method of diagnosis, site of disease and histological type were recorded. Date of onset of symptoms and performance status were obtained from clinical notes for a sample of cases. Cox regression was used to examine the association of the clinical variables and the 10-yr periods of disease onset with survival after diagnosis. Survival was inversely related to age, being worse for males (hazard ratio (HR) 1.4, 95% CI 1.2-1.6), and those with peritoneal mesothelioma (HR 1.4, 95% CI 1.1-1.7). Patients with sarcomatoid histology had worse prognosis than patients with epithelioid and biphasic histological subtypes. Survival improved after the 1970s and has made incremental improvements since then. Median (interquartile range) survival by decade, from 1960 until 2005, was 64 (0-198), 177 (48-350), 221 (97-504), 238 (108-502) and 301 (134-611) days; ~4 weeks of this apparent improvement can be attributed to earlier diagnosis. With increasing resources and treatment costs for MM over the past 40 yrs, there have been modest improvements in survival but no complete remissions.

Rainbow trout Oncorhynchus mykiss ladderlectin, but not intelectin, binds viral hemorrhagic septicemia virus IVb

The innate immune system of fish is critical for rapid detection and immediate response to infection, as well as to orchestrate the adaptive branch of the immune system. Rainbow trout Oncorhynchus mykiss ladderlectin and intelectin are plasma pattern recognition receptors (PRR) for bacterial and fungal pathogens of rainbow trout, but their role as PRRs for virus is unknown. Viral hemorrhagic septicemia virus (VHSV) IVb is a recently described fish pathogen in the Great Lakes, and rainbow trout can be experimentally infected. Using an indirect enzyme-linked immunosorbent assay, rainbow trout plasma ladderlectin significantly (p < 0.05) bound purified VHSV while intelectin did not. In addition, plasma ladderlectin but not intelectin was eluted from a VHSV-conjugated Toyopearl column using EDTA. Protein identification was confirmed with polyclonal antiserum used with slot immunoblot, 1-dimensional sodium dodecyl sulphate polyacrylamide electrophoresis, and Western immunoblot.

Daily co-trimoxazole prophylaxis in severely immunosuppressed HIV-infected adults in Africa started on combination antiretroviral therapy: an observational analysis of the DART cohort

BACKGROUND

Co-trimoxazole prophylaxis can reduce mortality from untreated HIV infection in Africa; whether benefits occur alongside combination antiretroviral therapy (ART) is unclear. We estimated the effect of prophylaxis after ART initiation in adults.

METHODS

Participants in our observational analysis were from the DART randomised trial of management strategies in HIV-infected, symptomatic, previously untreated African adults starting triple-drug ART with CD4 counts lower than 200 cells per muL. Co-trimoxazole prophylaxis was not routinely used or randomly allocated, but was variably prescribed by clinicians. We estimated effects on clinical outcomes, CD4 cell count, and body-mass index (BMI) using marginal structural models to adjust for time-dependent confounding by indication. DART was registered, number ISRCTN13968779.

FINDINGS

3179 participants contributed 14 214 years of follow-up (8128 [57%] person-years on co-trimoxazole). Time-dependent predictors of co-trimoxazole use were current CD4 cell count, haemoglobin concentration, BMI, and previous WHO stage 3 or 4 events on ART. Present prophylaxis significantly reduced mortality (odds ratio 0.65, 95% CI 0.50-0.85; p=0.001). Mortality risk reduction on ART was substantial to 12 weeks (0.41, 0.27-0.65), sustained from 12-72 weeks (0.56, 0.37-0.86), but not evident subsequently (0.96, 0.63-1.45; heterogeneity p=0.02). Variation in mortality reduction was not accounted for by time on co-trimoxazole or current CD4 cell count. Prophylaxis reduced frequency of malaria (0.74, 0.63-0.88; p=0.0005), an effect that was maintained with time, but we observed no effect on new WHO stage 4 events (0.86, 0.69-1.07; p=0.17), CD4 cell count (difference vs non-users, -3 cells per muL [-12 to 6]; p=0.50), or BMI (difference vs non-users, -0.04 kg/m(2) [-0.20 to 0.13); p=0.68].

INTERPRETATION

Our results reinforce WHO guidelines and provide strong motivation for provision of co-trimoxazole prophylaxis for at least 72 weeks for all adults starting combination ART in Africa.

FUNDING

UK Medical Research Council, the UK Department for International Development, the Rockefeller Foundation, GlaxoSmithKline, Gilead Sciences, Boehringer-Ingelheim, and Abbott Laboratories.

Viral haemorrhagic septicaemia virus IVb experimental infection of rainbow trout, Oncorhynchus mykiss (Walbaum), and fathead minnow, Pimphales promelas (Rafinesque)

Viral haemorrhagic septicaemia virus (VHSV) in the Great Lakes has had a dramatic impact on fish husbandry because of the implications of the presence of a reportable disease. Experimental infections with VHSV IVb were conducted in rainbow trout, Oncorhynchus mykiss (Walbaum), and fathead minnows, Pimphales promelas (Rafinesque), to examine their susceptibility and the clinical impact of infection. Triplicate groups of rainbow trout (n = 40) were injected intraperitoneally (i.p.) with 100 microL 10(6.5)50% tissue culture infective doses (TCID(50)) or waterborne exposed to graded doses (10(4.5), 10(6.5), and 10(8.5) TCID(50) mL(-1)) of VHSV IVb. Duplicate groups of fathead minnows (n = 15) were i.p. injected with (10(6.5) TCID(50) 100 microL) or waterborne exposed (10(6.5) TCID(50) mL(-1)). All experiments were performed with single-pass well water maintained at 12 degrees C. Following either i.p. or waterborne exposure, VHSV RNA was detectable in both rainbow trout and fathead minnows by nested reverse transcription polymerase chain reaction (nRT-PCR) as early as 4-7 days post-infection (p.i.). Infected fathead minnow and rainbow trout exhibited lesions characteristic of VHS at 9 and 15 days p.i., respectively. Route of exposure had little effect on the onset of clinical signs. Cumulative mean mortality in rainbow trout was 4.4%, 2.6%, 2.6% and less than 1% in the i.p., high, medium and low dose waterborne exposures, respectively. Cumulative average mortality of 50% and 13% occurred in i.p. and waterborne-exposed fathead minnows, respectively. VHSV was detected from pooled rainbow trout tissue by RT-PCR and virus isolation at 38 days p.i., but not at 74 days p.i., regardless of the exposure route. Immunohistochemistry (IHC) with a rabbit antibody to VHSV IVb revealed the viral tissue tropisms following infection, with the identification of viral antigen in myocardium and necrotic branchial epithelium of both species and in gonadal tissue of fathead minnows. Rainbow trout, but not fathead minnows, are relatively refractory to experimental infection with VHSV IVb.

Nevirapine/zidovudine/lamivudine has superior immunological and virological responses not reflected in clinical outcomes in a 48-week randomized comparison with abacavir/zidovudine/lamivudine in HIV-infected Ugandan adults with low CD4 cell counts

BACKGROUND

Triple nucleoside reverse transcriptase inhibitor regimens have advantages as first-line antiretroviral therapy (ART), avoiding hepatotoxicity and interactions with anti-tuberculosis therapy, and sparing two drug classes for second-line ART. Concerns exist about virological potency; efficacy has not been assessed in Africa.

METHODS

A safety trial comparing nevirapine with abacavir was conducted in two Ugandan Development of Antiretroviral Therapy in Africa (DART) centres: 600 symptomatic antiretroviral-naïve HIV-infected adults with CD4 counts <200 cells/microL were randomized to zidovudine/lamivudine plus abacavir or nevirapine (placebo-controlled to 24-week primary toxicity endpoint, and then open-label). Documented World Health Organization (WHO) stage 4 events were independently reviewed and plasma HIV-1 RNA assayed retrospectively. Exploratory efficacy analyses are intention-to-treat.

RESULTS

The median pre-ART CD4 count was 99 cells/microL, and the median pre-ART viral load was 284 600 HIV-1 RNA copies/mL. A total of 563 participants (94%) completed 48 weeks of follow-up, 25 (4%) died and 12 (2%) were lost to follow-up. The randomized drug was substituted in 21 participants (7%) receiving abacavir vs. 34 (11%) receiving nevirapine (P=0.09). At 48 weeks, 62% of participants receiving abacavir vs. 77% of those receiving nevirapine had viral loads <50 copies/mL (P<0.001), and mean CD4 count increases from baseline were +147 vs. +173 cells/microL, respectively (P=0.006). Nine participants (3%) receiving abacavir vs. 16 (5%) receiving nevirapine died [hazard ratio (HR) 0.55; 95% confidence interval (CI) 0.24-1.25; P=0.15]; 20 receiving abacavir vs. 32 receiving nevirapine developed new or recurrent WHO 4 events or died (HR=0.60; 95% CI 0.34-1.05; P=0.07) and 48 receiving abacavir vs. 68 receiving nevirapine developed new or recurrent WHO 3 or 4 events or died (HR=0.67; 95% CI 0.46-0.96; P=0.03). Seventy-one participants (24%) receiving abacavir experienced 91 grade 4 adverse events compared with 130 events in 109 participants (36%) on nevirapine (P<0.001).

CONCLUSIONS

The clear virological/immunological superiority of nevirapine over abacavir was not reflected in clinical outcomes over 48 weeks. The inability of CD4 cell count/viral load to predict initial clinical treatment efficacy is unexplained and requires further evaluation.

Routine versus clinically driven laboratory monitoring of HIV antiretroviral therapy in Africa (DART): a randomised non-inferiority trial

BACKGROUND

HIV antiretroviral therapy (ART) is often managed without routine laboratory monitoring in Africa; however, the effect of this approach is unknown. This trial investigated whether routine toxicity and efficacy monitoring of HIV-infected patients receiving ART had an important long-term effect on clinical outcomes in Africa.

METHODS

In this open, non-inferiority trial in three centres in Uganda and one in Zimbabwe, 3321 symptomatic, ART-naive, HIV-infected adults with CD4 counts less than 200 cells per microL starting ART were randomly assigned to laboratory and clinical monitoring (LCM; n=1659) or clinically driven monitoring (CDM; n=1662) by a computer-generated list. Haematology, biochemistry, and CD4-cell counts were done every 12 weeks. In the LCM group, results were available to clinicians; in the CDM group, results (apart from CD4-cell count) could be requested if clinically indicated and grade 4 toxicities were available. Participants switched to second-line ART after new or recurrent WHO stage 4 events in both groups, or CD4 count less than 100 cells per microL (LCM only). Co-primary endpoints were new WHO stage 4 HIV events or death, and serious adverse events. Non-inferiority was defined as the upper 95% confidence limit for the hazard ratio (HR) for new WHO stage 4 events or death being no greater than 1.18. Analyses were by intention to treat. This study is registered, number ISRCTN13968779.

FINDINGS

Two participants assigned to CDM and three to LCM were excluded from analyses. 5-year survival was 87% (95% CI 85-88) in the CDM group and 90% (88-91) in the LCM group, and 122 (7%) and 112 (7%) participants, respectively, were lost to follow-up over median 4.9 years' follow-up. 459 (28%) participants receiving CDM versus 356 (21%) LCM had a new WHO stage 4 event or died (6.94 [95% CI 6.33-7.60] vs 5.24 [4.72-5.81] per 100 person-years; absolute difference 1.70 per 100 person-years [0.87-2.54]; HR 1.31 [1.14-1.51]; p=0.0001). Differences in disease progression occurred from the third year on ART, whereas higher rates of switch to second-line treatment occurred in LCM from the second year. 283 (17%) participants receiving CDM versus 260 (16%) LCM had a new serious adverse event (HR 1.12 [0.94-1.32]; p=0.19), with anaemia the most common (76 vs 61 cases).

INTERPRETATION

ART can be delivered safely without routine laboratory monitoring for toxic effects, but differences in disease progression suggest a role for monitoring of CD4-cell count from the second year of ART to guide the switch to second-line treatment.

FUNDING

UK Medical Research Council, the UK Department for International Development, the Rockefeller Foundation, GlaxoSmithKline, Gilead Sciences, Boehringer-Ingelheim, and Abbott Laboratories.

Acute cytomegalovirus cholecystitis following renal transplantation

Solid organ transplant recipients are at risk of infection from cytomegalovirus (CMV). A wide range of disease is associated with CMV infection and we report two cases of CMV cholecystitis in patients following renal transplantation. Both patients presented with severe hemorrhagic cholecystitis, which required immediate resuscitation and emergency cholecystectomy. The diagnosis of CMV infection was confirmed in both cases using CMV-specific staining of the gallbladder. The diagnosis of CMV cholecystitis must be considered in all patients with upper abdominal pain after renal transplantation.

Heterogeneity and clinical significance of ETV1 translocations in human prostate cancer

A fluorescence in situ hybridisation (FISH) assay has been used to screen for ETV1 gene rearrangements in a cohort of 429 prostate cancers from patients who had been diagnosed by trans-urethral resection of the prostate. The presence of ETV1 gene alterations (found in 23 cases, 5.4%) was correlated with higher Gleason Score (P=0.001), PSA level at diagnosis (P=<0.0001) and clinical stage (P=0.017) but was not linked to poorer survival. We found that the six previously characterised translocation partners of ETV1 only accounted for 34% of ETV1 re-arrangements (eight out of 23) in this series, with fusion to the androgen-repressed gene C15orf21 representing the commonest event (four out of 23). In 5'-RACE experiments on RNA extracted from formalin-fixed tissue we identified the androgen-upregulated gene ACSL3 as a new 5'-translocation partner of ETV1. These studies report a novel fusion partner for ETV1 and highlight the considerable heterogeneity of ETV1 gene rearrangements in human prostate cancer.

A surgical robot for cochleostomy

In this paper a robotic micro-drilling technique for surgery is described. The device has been deployed in cochleostomy, a precise micro-surgical procedure where the critical stage of controlling penetration of the outer bone tissue of the cochlea is achieved without penetration of the endosteal membrane at the medial surface. The significance of the work is that the device navigates by using transients of the reactive drilling forces to discriminate cutting conditions, state of tissue and the detection of the medial surface before drill break-out occurs. This is the first autonomous surgical robot to use this technique in real-time as a navigation function in the operating room and unlike other fully autonomous surgical robotic processes it is carried out without the use pre-operative data to control the motion of the tool. To control tool points in flexible tissues requires self-referencing to the tissue position in real time. There is also the need to discriminate deflections of the tissue, tissue interface, involuntary patients/tissue movement and indeed movement induced by the drill itself, which require different strategies to be selected for control. As a result of the design of the final system, the break-out process of the drill can either controlled to the required level of protrusion through the flexible interface or can be avoided altogether, with the drill bit at the medial surface. This enables, for the first time, the control of fine penetration with such great precision.

Global monitoring of collaborative TB-HIV activities

Tuberculosis (TB) and human immunodeficiency virus (HIV) programs are increasingly working together towards providing universal access to integrated TB and HIV prevention, treatment, care and support services. To monitor progress we need to measure the delivery and impact of these services; however, the lack of investment in monitoring and evaluation and the added complexity of sharing data between two vertical programs, makes monitoring and evaluation of collaborative TB-HIV activities especially challenging. We describe the global system to record, report and analyse data on collaborative TB-HIV activities and summarize results to date. Although the data suggest that there is a steady increase in collaborative TB-HIV activities in many high-burden countries over time, we are already falling behind the globally agreed implementation milestones. This is due to a combination of slow implementation and lack of necessary tools and systems for capturing activity data. In particular, data from HIV program monitoring of TB screening, TB preventive treatments and TB infection control for people living with HIV is lacking. Much remains to be done by both programs to improve the implementation, monitoring and evaluation of collaborative TB-HIV activities and to optimize prevention, treatment and care for people infected with both TB and HIV, especially in areas at high risk of drug-resistant TB.

Mortality of former crocidolite (blue asbestos) miners and millers at Wittenoom

BACKGROUND

Blue asbestos was mined and milled at Wittenoom in Western Australia between 1943 and 1966.

METHODS

Nearly 7000 male workers who worked at the Wittenoom mine and mill have been followed up using death and cancer registries throughout Australia and Italy to the end of 2000. Person-years at risk were derived using two censoring dates in order to produce minimum and maximum estimates of asbestos effect. Standardised mortality ratios (SMRs) compare the mortality of the former Wittenoom workers with the Western Australian male population.

RESULTS

There have been 190 cases of pleural and 32 cases of peritoneal mesothelioma in this cohort of former workers at Wittenoom. Mortality from lung cancer (SMR = 1.52), pneumoconiosis (SMR = 15.5), respiratory diseases (SMR = 1.58), tuberculosis (SMR = 3.06), digestive diseases (SMR = 1.47), alcoholism (SMR = 2.24) and symptoms, signs and ill defined conditions (SMR = 2.00) were greater in this cohort compared to the Western Australian male population.

CONCLUSION

Asbestos related diseases, particularly malignant mesothelioma, lung cancer and pneumoconiosis, continue to be the main causes of excess mortality in the former blue asbestos miners and millers of Wittenoom.

First in-human phase 1 trial of a novel amino-peptidase inhibitor, CHR-2797

3537

Background: CHR-2797 is a novel, orally bioavailable agent which displays potent, tumor cell-selective, anti-proliferative properties. It is an inhibitor of Zn++-dependent aminopeptidases and generates signs of amino acid deprivation in sensitive cells, decreased protein synthesis and an increase in the level of the pro-apoptotic protein, Noxa. CHR-79888 is an active metabolite of CHR-2797. Patients and Methods: This study was conducted according to an accelerated titration design to define the MTD, DLT, toxicity profile and PK of CHR-2797 when administered orally for 28 days or longer. Patients (ECOG PS = 2) with histologically confirmed advanced solid tumors resistant or refractory to standard therapy were eligible. Results: 37 pts (median age 61.5 years [range 22.4–80.1]; 30M/7F; median ECOG PS 1; median prior regimens 2, range 0–6) enrolled in 12 cohorts (doses between 10 and 320mg). The first four patients received a 10 mg dose for 7, 14, 21 or 28 days respectively. Subsequent cohorts received 28 days continuous dosing, with dose doubling in single patient cohorts until drug-related toxicity = Grade 2. Thereafter the study followed a 3+3 design with = 40% dose increments. Common (gr 1–2) toxicity included fatigue (47%), diarrhea (47%), dizziness (24%), constipation, vomiting, abdominal pain (all 21%), and thrombocytopenia (18%). Toxicities show dose dependency for thrombocytopenia and fatigue. MTD was declared at 320 mg after 2 DLT’s were reported: 2 patients were unable to complete 28 days of daily dosing due to syncope/anemia, and dizziness/visual disturbances/thrombocytopenia, respectively. Patients recovered fully after cessation of the drug. The dose level below (240 mg) was expanded to 13 patients. Plasma PK was determined for both CHR-2797 and -79888, on days 1 and 28, which showed dose proportional increases in AUC and Cmax. Intracellular and intratumoral levels of both the parent and metabolite were also measured. So far 4 patients continued therapy for 7–9 months: one patient (RCC [130 mg]) achieved a PR, and 3 patients (ovarian ca [40 mg], NSCLC [130 mg], and breast ca [180 mg] had confirmed SD (> 3 months). Conclusion: Once daily oral CHR-2797 can be administered safely for 28 days in doses up to 240 mg and exhibits favorable PK.

No significant financial relationships to disclose.

Romidepsin (FK228), a histone deacetylase inhibitor: Final results of a phase II study in metastatic hormone refractory prostate cancer (HRPC)

15507

Background: Romidepsin is a bicyclic depsipeptide that inhibits histone deacetylase (HDAC). Translocations fusing TMPRSS2 gene and ERG oncogenic factor is associated with elevated HDAC-1 expression. HDAC inhibition results in accumulation of hyperacetylated histone proteins resulting in G1 and G2/M arrest, differentiation of transformed cells and apoptosis. Romidepsin can also inhibit HSP90, ablating androgen receptor expression. This is the 1st study to report activity of an HDAC inhibitor in HRPC. Methods: Romidepsin was administered intravenously at 13mg/m2 on days 1, 8 and 15 of a 28-day schedule. A 2-stage design was used. Eligibility criteria included: no prior chemotherapy, metastatic disease, QTcB <470msec, Karnofsky PS =80. The primary endpoint was to determine rate of disease control (complete response [CR], partial response [PR], stable disease [SD] for 6 months). Secondary endpoints were PSA response rate (RR), time to PSA and objective disease progression, safety profile, effect on disease related symptoms and pharmacokinetics (PK) of romidepsin. Results: Thirty-one patients were enrolled. Median age: 64 years (range 43–82). Twenty-one patients are evaluable for radiological and PSA response: 1 patient achieved a confirmed radiological PR lasting >6 months (m), and 2 confirmed SD for 6m. Four patients had SD lasting 5m (n=2) and 4m (n=2). The PSA RR was 7%. A 3rd patient had a 40% fall in PSA lasting 5m. The most common drug related adverse events were (all grades, %): nausea (84%), fatigue (77%), vomiting (65%), anorexia (61%), constipation (45%), dysguesia (35%), diarrhea (32%), thrombocytopaenia (32%), anemia (28%) and neutropenia (25%). There were no grade 4 events. Non-specific asymptomatic ST segment changes on ECG were seen in 15 % of patients; there was no evidence of significant QTc prolongation on ECG confirmed by manual calculation. Conclusions: Treatment with single agent romidepsin is associated with a disease control rate of 14% and a PSA RR of 7%. Constitutional toxicities are prominent, no grade 4 events have been observed and only minimal cardiac toxicity has been reported. Further investigation in combination with other active agents in HRPC is warranted.

[Table: see text]

Rural–urban differences in the presentation, management and survival of breast cancer in Western Australia

From all women diagnosed with invasive breast cancer in 1999 in Western Australia, rural and urban women were compared with regard to mode of detection, tumour characteristics at presentation, diagnostic investigations, treatment and survival. Women from rural areas with breast cancer (n=206, 23%) were less likely to have open biopsy with frozen section (P<0.001), breast-conserving surgery (P<0.001), adjuvant radiotherapy (P=0.004) and hormonal therapy (P=0.03), and were less likely to be treated by a high caseload breast cancer surgeon (P<0.001). Adjusting for age and tumour characteristics, rural women had an increased likelihood of death within 5 years of breast cancer diagnosis (HR 1.62, 95% CI 1.10-2.38). This difference was not significant after adjustment for treatment factors (HR 1.36, 95% CI 0.90-2.04).

Occurrence of infected amoebae in cooling towers compared with natural aquatic environments: implications for emerging pathogens

Many species of bacteria pathogenic to humans, such as Legionella, are thought to have evolved in association with amoebal hosts. Several novel unculturable bacteria related to Legionella have also been found in amoebae, a few of which have been thought to be causes of nosocomial infections in humans. Because amoebae can be found in cooling towers, we wanted to know whether cooling tower environments might enhance the association between amoebae and bacterial pathogens of amoebae in order to identify potential "hot spots" for emerging human pathogens. To compare occurrence of infected amoebae in natural environments with those in cooling towers, 40 natural aquatic environments and 40 cooling tower samples were examined. Logistic regression analysis determined variables that were significant predictors of the occurrence of infected amoebae, which were found in 22 of 40 cooling tower samples but in only 3 of the 40 natural samples. An odds ratio showed that it is over 16 times more likely to encounter infected amoebae in cooling towers than in natural environments. Environmental data from cooling towers and natural habitats combined revealed dissolved organic carbon (DOC) and pH were predictors of the occurrence of the pathogens, however, when cooling tower data alone were analyzed, no variables accounted for the occurrence. Several bacteria have novel rRNA sequences, and most strains were not culturable outside of amoebae. Such pathogens of amoebae may spread to the environment via aerosols from cooling towers. Studies of emerging infectious diseases should strongly consider cooling towers as a source of amoeba-associated pathogens.

The risk of lung cancer with increasing time since ceasing exposure to asbestos and quitting smoking

OBJECTIVES

To examine if the risk of lung cancer declines with increasing time since ceasing exposure to asbestos and quitting smoking, and to determine the relative asbestos effect between non-smokers and current smokers.

METHODS

A cohort study of 2935 former workers of the crocidolite mine and mill at Wittenoom, who responded to a questionnaire on smoking first issued in 1979 and on whom quantitative estimates of asbestos exposure are known. Conditional logistic regression was used to relate asbestos exposure, smoking category, and risk of lung cancer.

RESULTS

Eighteen per cent of the cohort reported never smoking; 66% of cases and 50% of non-cases were current smokers. Past smokers who ceased smoking within six years of the survey (OR = 22.1, 95% CI 5.6 to 87.0), those who ceased smoking 20 or more years before the survey (OR = 1.9, 95% CI 0.50 to 7.2), and current smokers (<20 cigarettes per day (OR = 6.8, 95% CI 2.0 to 22.7) or >20 cigarettes per day (OR = 13.2, 95% CI 4.1 to 42.5)) had higher risks of lung cancer compared to never smokers after adjusting for asbestos exposure and age. The asbestos effect between non-smokers and current smokers was 1.23 (95% CI 0.35 to 4.32).

CONCLUSION

Persons exposed to asbestos and tobacco but who subsequently quit, remain at an increased risk for lung cancer up to 20 years after smoking cessation, compared to never smokers. Although the relative risk of lung cancer appears higher in never and ex-smokers than in current smokers, those who both smoke and have been exposed to asbestos have the highest risk; this study emphasises the importance of smoking prevention and smoking cessation programmes within this high risk cohort.

Improving the outcome of patients with castration-resistant prostate cancer through rational drug development

Castration-resistant prostate cancer (CRPC) is now the second most common cause of male cancer-related mortality. Although docetaxel has recently been shown to extend the survival of patients with CRPC in two large randomised phase III studies, subsequent treatment options remain limited for these patients. A greater understanding of the molecular causes of castration resistance is allowing a more rational approach to the development of new drugs and many new agents are now in clinical development. Therapeutic targets include the adrenal steroid synthesis pathway, androgen receptor signalling, the epidermal growth factor receptor family, insulin growth factor-1 receptor, histone deacetylase, heat shock protein 90 and the tumour vasculature. Drugs against these targets are giving an insight into the molecular pathogenesis of this disease and promise to improve patient quality of life and survival. Finally, the recent discovery of chromosomal translocations resulting in the upregulation of one of at least 3 ETS genes (ERG, ETV1, ETV4) may lead to novel agents for the treatment of this disease.

Phase I pharmacokinetic (PK) and pharmacodynamic (PD) evaluation of a small molecule inhibitor of Poly ADP-Ribose Polymerase (PARP), KU-0059436 (Ku) in patients (p) with advanced tumours

3022

Background: PARP is a DNA strand break and base damage repair enzyme. Ku inhibits PARP-1 and 2 with a mean IC50 of 2nM. Inhibition of PARP leads to defective DNA repair and induces selective cytotoxicity in cells with defective homologous recombination repair through, for example, loss of BRCA 1/2 function (Farmer et al, Nature 2005 Apr 14;434(7035):917–21). This is a first in man Phase I trial of Ku. PD studies included functional evaluation of PARP-1 activity in surrogate and tumor tissue. Methods: Ku was administered once a day for 14 of every 21 days to p with advanced solid tumors refractory to standard treatment. Cohorts of 3–6 p were treated, with a starting dose of 10 mg/day. The dose was doubled in the absence of drug related grade 2 CTC-AE toxicity. Drug related toxicity in cancer patients known to carry a BRCA mutation is being compared to toxicity in other patients. Results: To date 12 p (6 male; median age 55y, range 25–73) with solid tumours have received 25 courses (range 1–8), with 1 p being a known BRCA1 mutation carrier (dose level 40mg). Dose levels evaluated to date include 10, 20, 40, and 80mg per day. Minimal toxicity has been observed to date, with only intermittent grade 1 nausea being reported. PK data to date, up to 40mg per day, supports dose proportionality with a mean elimination half-life of 6.91 hours (Range: 5.3–9.5), a mean clearance of 4.1 L/h (Range: 1.3–9.4) and a mean volume of distribution of 39.8 L (Range: 16.3–86.9). PD studies indicate inhibition of PARP functional activity in peripheral blood mononuclear cells with increasing inhibition observed with increasing dose of Ku. Initial studies in tumor biopsies performed pre-treatment and on day 8 revealed PARP inhibition of >50% at 40 mg/day. A p with metastatic soft tissue sarcoma and progressing disease pretreatment achieved stable disease for 24 weeks. Conclusions: Dose escalation continues with more BRCA carriers planned. PARP inhibition in both surrogate and tumor tissue is achievable with minimal toxicity in cancer patients, and has not resulted in any short term toxicity in a BRCA mutation carrier.

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A phase 1 dose finding study of CHR-2797, an inhibitor of M1 aminopeptidases, in patients with advanced solid tumours

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Background: CHR-2797 is a novel, orally bioavailable inhibitor of the M1 family of aminopeptidases, in particular PuSA, and LTA4 hydrolase. Exposure of cancer cells to CHR-2797 results in the generation of the active metabolite CHR-79888 which is poorly membrane-permeable, resulting in intracellular accumulation. CHR-2797 has shown anti-proliferative activity in syngeneic (rat) and xenograft (mouse) cancer models, and is anti-angiogenic in vitro. Methods: Patients (pts) (ECOG PS ≤ 2) with histologically confirmed advanced solid tumors resistant or refractory to standard therapy were eligible. The accelerated titration design of the trial involved two phases for evaluation of schedule and dose: 1) fixed dose with increasing duration, and 2) dose escalation over a fixed duration (28 days). Results: 16 pts (median age: 64.5 years [range 48.8–80.1], 13M/3F)were treated with once daily doses ranging from 10mg to 130mg. The first four patients received a 10mg dose for 7, 14, 21 or 28 days respectively. Five subsequent cohorts received 28 days continuous dosing, with dose doubling in single patient cohorts until drug-related toxicity ≥ Grade 2. Thereafter dose was escalated in ≤ 40% increments in 3-patient cohorts. The most frequent adverse events were: gr 1–2 thrombocytopenia (44%), gr 1 diarrhea (25%), gr 1–2 transaminitis (19%), gr 1–2 fatigue (13%), gr 1 hot flushes (13%), and gr 1 lightheadedness (13%). There were no DLTs. Five patients continued therapy after 28 days; stable disease has been achieved in 1 pt for 6 months with granulosa cell carcinoma of ovary, who was progressing prior to study entry. CHR-2797 and CHR-79888 demonstrate dose proportional increases in AUC and Cmax. The terminal half-life for CHR-2797 is around 1–2 hours, whereas it is between 9 and 11 hours for CHR-79888. Intracellular (packed blood cells) exposure to both CHR-2797 and CHR-79888 is good, with CHR-79888 accumulating over 28 days, such that by day 28 the intracellular levels are comparable to plasma. Conclusions: CHR-2797 is well tolerated and can be safely administered at doses that reach plasma concentrations associated with activity in pre-clinical models. Accrual into the study continues.

No significant financial relationships to disclose.

Phase I trial involving the pharmacodynamic (PD) study of circulating tumour cells, of CP-751,871 (C), a monoclonal antibody against the insulin-like growth factor 1 receptor (IGF-1R), with docetaxel (D) in patients (p) with advanced cancer

3023

Background: C is the first specific, fully human, monoclonal antibody to target IGF-1R in clinical trials. It potently inhibits IGF-1R signaling, enhancing D antitumour activity. This trial investigated the safety, feasibility, dose limiting toxicity (DLT), PK and antitumor activity of D administered with C every 3 weeks. PD studies evaluated circulating tumor cell (CTC) IGF-1R expression and CTC counts pre- and post-treatment. Methods: The C doses tested were 0.1, 0.4, 0.8, 1.5, 3.0, 6.0 and 10 mg/kg in sequential cohorts of 3–6 p. D was fixed at 75mg/m2. P achieving disease control continued on C alone if experiencing D toxicity. Results: 21 p (20 male) have received 100 courses of C with D. 7 p received 8 or more courses of the combination. A further 21 courses of C alone have been administered. No toxicity has been attributed to C to date with the observed toxicities being attributable to D. Grade 3/4 toxicities were neutropenia (16/21 p) and neutropenic fever in 2/21 p. Grade 3 diarrhea was reported in 3 p, but this was easily controlled with antidiarrheals. Transient grade 1 hyperglycaemia was noted largely on day 1, following steroid premedication (14 p), but no significant C related hyperglycemia has been observed. An MTD has not been reached. Serial echocardiograms demonstrated no cardiac toxicity. Of 18 castration resistant prostate cancer (CRPC) p treated, 4 have had a confirmed PR, with 2 unconfirmed PR and 2 having disease stabilization for > 6 months (median number of courses: 10; range: 3–12). 5 p have maintained SD with C alone for 2–7 courses. CTC were detected in 16 of 18 p (CTC numbers ranged from 1 to 202 in 7.5ml of blood). IGF-1R expression was detected in 12 p. CTC IGF-1R was undetectable following treatment with C at doses above 3 mg/kg. Conclusions: This combination is safe and feasible with no toxicity attributed to C and encouraging antitumor activity in CRPC.

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