Cutaneous sarcoidosis due to immune‐checkpoint inhibition and exacerbated by a novel BRAF dimerization inhibitor

Sarcoidosis is a non‐infective granulomatous disorder of unknown aetiology, with cutaneous involvement affecting up to 30% of patients. Drug‐induced sarcoidosis has been reported secondary to modern melanoma therapies including immune‐checkpoint inhibitors and first generation BRAF inhibitors such as vemurafenib and dabrafenib. Herein, we report a case of cutaneous micropapular sarcoidosis that first developed on immune‐checkpoint inhibition with ipilimumab and nivolumab for metastatic melanoma, which was exacerbated and further complicated by pityriasis rubra pilaris‐like palmar plaques upon transition to a next‐generation BRAF‐dimerisation inhibitor. Both the micropapular eruption and palmar plaques rapidly resolved after cessation of the novel BRAF‐inhibitor and concurrent commencement of hydroxychloroquine. It is unclear how inhibition of BRAF‐dimerisation results in granuloma formation, though upregulation of T_H1/T_H17 T‐cells and impairment of T‐reg cells may be responsible. Clinicians should be aware of the potential for exacerbation of sarcoidosis when transitioning from immune‐checkpoint inhibitors to these novel BRAF‐dimerisation inhibitors, particularly as their uptake in treating cancers increases beyond clinical trials. Further studies are required to assess whether these next‐generation agents can trigger sarcoidosis de‐novo, or simply exacerbate pre‐existing sarcoidosis.

Barriers and facilitators related to undertaking physical activities among men with prostate cancer: a scoping review

BACKGROUND

Prostate cancer (PC) and its treatments lead to significant acute, chronic, or latent adverse effects that result in declines in patients' physical functions, quality of life and reduced sense of masculinities. Robust evidence shows that physical activity (PA) can improve many health outcomes in men with PC; however, less is known about the facilitators, preferences, and barriers to PA engagement in this population. The purpose of this scoping review is to document the nature and extent of literature related to these aspects of PA participation among men with PC.

METHODS

We conducted a scoping review of PA among men with PC. Databases searched included Medline, CINAHL, Embase, Rehabilitation & Sports Medicine Source, and SportDiscus from inception to June 30, 2020. Multiple reviewers were used in all screening and data abstractions.

RESULTS

The search yielded 2788 individual citations after duplicates were removed. Following title and abstract screening, 129 underwent full-text review, and 46 articles were included. Quantitative data related to our research question showed that structured group exercise was the most commonly reported facilitator/preference among men with PC, whereas treatment-related effects and lack of time are the most common barriers. In terms of qualitative data, the most prominent theme noted related to masculinities and gender-specific needs within the context of having PC.

CONCLUSION

Men with PC have unique facilitators and barriers concerning PA. More work is needed from the research and clinical practice perspectives to enable this population to engage and remain in regular PA.

Five-year survival outcomes for patients with advanced melanoma treated with pembrolizumab in KEYNOTE-001

BACKGROUND

Pembrolizumab demonstrated robust antitumor activity and safety in the phase Ib KEYNOTE-001 study (NCT01295827) of advanced melanoma. Five-year outcomes in all patients and treatment-naive patients are reported herein. Patients whose disease progressed following initial response and who received a second course of pembrolizumab were also analyzed.

PATIENTS AND METHODS

Patients aged ≥18 years with previously treated or treatment-naive advanced/metastatic melanoma received pembrolizumab 2 mg/kg every 3 weeks, 10 mg/kg every 3 weeks, or 10 mg/kg every 2 weeks until disease progression, intolerable toxicity, or patient/investigator decision to withdraw. Kaplan-Meier estimates of overall survival (OS) and progression-free survival (PFS) were calculated. Objective response rate and PFS were based on immune-related response criteria by investigator assessment (data cut-off, September 1, 2017).

RESULTS

KEYNOTE-001 enrolled 655 patients with melanoma; median follow-up was 55 months. Estimated 5-year OS was 34% in all patients and 41% in treatment-naive patients; median OS was 23.8 months (95% CI, 20.2-30.4) and 38.6 months (95% CI, 27.2-not reached), respectively. Estimated 5-year PFS rates were 21% in all patients and 29% in treatment-naive patients; median PFS was 8.3 months (95% CI, 5.8-11.1) and 16.9 months (95% CI, 9.3-35.5), respectively. Median response duration was not reached; 73% of all responses and 82% of treatment-naive responses were ongoing at data cut-off; the longest response was ongoing at 66 months. Four patients [all with prior response of complete response (CR)] whose disease progressed during observation subsequently received second-course pembrolizumab. One patient each achieved CR and partial response (after data cut-off). Treatment-related AEs (TRAEs) occurred in 86% of patients and resulted in study discontinuation in 7.8%; 17% experienced grade 3/4 TRAE.

CONCLUSIONS

This 5-year analysis of KEYNOTE-001 represents the longest follow-up for pembrolizumab to date and confirms the durable antitumor activity and tolerability of pembrolizumab in advanced melanoma.

CLINICAL TRIAL REGISTRY

ClinicalTrials.gov, NCT01295827.

Delayed immune-related adverse events in assessment for dose-limiting toxicity in early phase immunotherapy trials

BACKGROUND

Immunotherapy (IO) agents can cause late-onset immune-related adverse events (irAEs). In phase I trials, observation for dose-limiting toxicities (DLTs) is typically limited to the first cycle. The incidence of delayed-onset DLTs and their potential impact on dose determination have not been fully elucidated.

PATIENTS AND METHODS

Consecutive patients enrolled in early phase IO trials at Princess Margaret Cancer Centre between August 2012 and September 2016 were retrospectively reviewed, applying trial-specific definitions for DLTs. A clinically significant AE (csAE) was defined as a treatment-related adverse event requiring corticosteroids, hormone replacement, IO delay or discontinuation.

RESULTS

A total of 352 consecutive trial enrolments in 21 early phase clinical trials were included. Two-hundred seventy-eight patients (79%) received monotherapy and 74 (21%) received combination IO. Two hundred sixty (74%) patients experienced irAEs. There were two protocol-defined DLTs. Twenty (5.7%) patients had 24 csAEs qualifying as DLTs except for occurrence after the protocol-specified DLT period. One-hundred and six (10%) of irAEs were csAEs, including endocrine (26%), respiratory (14%), gastrointestinal (11%), general (10%), dermatological (8%), hepatic (8%), musculoskeletal (6%), pancreatic (6%), haematological, metabolic, neurological, cardiac (each 2%), infective and ocular (each 1%) events. The highest risk of first-onset csAE was during the first 4 weeks compared with the period from 4 weeks to end of treatment (odds ratio 3.13, 95% confidence interval 1.95-5.02). The median time to first onset csAE was significantly shorter with combination than monotherapy IO (32 vs. 146 days, P < 0.001).

CONCLUSIONS

In our series of early phase IO trials, the risk of csAE was highest during the initial 4 weeks on IO treatment, supporting the use of the conventional DLT period for dose escalation decision. However, there were 24 clinically significant late-onset DLTs in 5.7% of patients. Combination IO was associated with greater risk of and also earlier onset for csAE, which may need to be considered for early phase trial design.

Resource utilization and costs of managing patients with advanced melanoma: a Canadian population-based study

BACKGROUND

The use and detailed costs of services provided for people with advanced melanoma (amel) are not well known. We conducted an analysis to determine the use of health care services and the associated costs delineated by relevant attributable costs, which we defined for subjects in the province of Ontario.

METHODS

Through the Ontario Cancer Data Linkage Project, a cohort of amel patients with diagnoses between 31 August 2005 and 2012 (follow-up to 2013) and with valid International Classification of Diseases (9th revision, Clinical Modification) 172 codes and histology codes was identified. A cohort of individuals with amel having a combination of at least 1 palliative, 1 medical oncology, and 1 hospitalization code was generated. The health system services used by this population were clustered into hospitalization, palliation, physician medical visits, medication, homecare, laboratory, diagnostics, and other resources. Overall rates of use and disaggregated costs were determined by phase of care for the entire cohort.

RESULTS

The mean age for the 2748 individuals in the cohort was 67 years. The greater proportion of the patients were men (65.6%) and were more than 65 years of age (>50%). In this advanced cohort, fewer than 45% of patients were alive 3 years after the malignant melanoma diagnosis. The average annual cost per patient over the time horizon was $6,551. At $15,830, year 1 after diagnosis was the most expensive, followed by year 2, at $8,166.

CONCLUSIONS

Our data provide a baseline for the costs associated with amel treatment. Future studies will include newer agents and comparative effectiveness research for personalized therapies.

Up-regulation of autophagy is a mechanism of resistance to chemotherapy and can be inhibited by pantoprazole to increase drug sensitivity

BACKGROUND

Autophagy is a survival mechanism that allows recycling of cellular breakdown products, particularly in stressed cells. Here we evaluate the hypotheses that up-regulation of autophagy is a common mechanism of resistance to chemotherapy, and that drug resistance can be reversed by inhibiting autophagy with a proton pump inhibitor.

METHODS

We exposed human PC3, LNCaP and MCF7 cells to seven clinically-used chemotherapy drugs ± pantoprazole, examined the up-regulation of autophagy and the effect on cellular proliferation by Western Blots, MTS assay and colony-forming assay. The distribution of drug effects and of autophagy was quantified in LNCaP tumor sections in relation to blood vessels and hypoxia by immunohistochemistry using γH2AX, cleaved caspase-3 and p62.

RESULTS

All anticancer drugs led to up-regulation of autophagy in cultured tumor cells. Pantoprazole inhibited the induction of autophagy in a time- and dose-dependent manner, and sensitized cancer cells to the seven anti-cancer drugs. Treatment of LNCaP xenografts with paclitaxel induced both DNA damage and autophagy; autophagy was inhibited and markers of toxicity were increased by pantoprazole.

CONCLUSIONS

Induction of autophagy is a general mechanism associated with resistance to anticancer drugs and that its inhibition is a promising therapeutic strategy to enhance the effects of chemotherapy and improve clinical outcomes.

Burden of illness for metastatic melanoma in Canada, 2011-2013

BACKGROUND

Detailed epidemiology for patients with advanced metastatic melanoma in Canada is not well characterized. We conducted an analysis of patients with this disease in the province of Ontario, with the aim being to study the presentation, disease characteristics and course, and treatment patterns for malignant melanoma.

METHODS

In this Canadian observational prospective and retrospective study of patients with malignant melanoma, we used data collected in the Canadian Melanoma Research Network (cmrn) Patient Registry. We identified patients who were seen at 1 of 3 cancer treatment centres between April 2011 and 30 April 2013. Patient data from 2011 and 2012 were collected retrospectively using chart records and existing registry data. Starting January 2013, data were collected prospectively. Variables investigated included age, sex, initial stage, histology, mutation type, time to recurrence, sites of metastases, resectability, and previous therapies.

RESULTS

A cohort of 810 patients with melanoma was identified from the cmrn registry. Mean age was 58.7 years, and most patients were men (60% vs. 40%). Factors affecting survival included unresectable or metastatic melanoma, initial stage at diagnosis, presence of brain metastasis, and BRAF mutation status. The proportion of surviving patients decreased with higher initial disease stages.

CONCLUSIONS

Using registry data, we were able to determine the detailed epidemiology of patients with melanoma in the Canadian province of Ontario, validating the comprehensive and detailed information that can be obtained from registry data.

A prognostic index model for predicting overall survival in patients with metastatic castration-resistant prostate cancer treated with abiraterone acetate after docetaxel

A prognostic index model was developed, composed of six readily available and assessable factors and categorizing patients with metastatic castration-resistant prostate cancer treated with abiraterone–prednisone into distinct prognostic risk groups. This model could be useful for determining patient prognosis for follow-up, monitoring and patient stratification for clinical trials.

Background

Few prognostic models for overall survival (OS) are available for patients with metastatic castration-resistant prostate cancer (mCRPC) treated with recently approved agents. We developed a prognostic index model using readily available clinical and laboratory factors from a phase III trial of abiraterone acetate (hereafter abiraterone) in combination with prednisone in post-docetaxel mCRPC.

Patients and methods

Baseline data were available from 762 patients treated with abiraterone–prednisone. Factors were assessed for association with OS through a univariate Cox model and used in a multivariate Cox model with a stepwise procedure to identify those of significance. Data were validated using an independent, external, population-based cohort.

Results

Six risk factors individually associated with poor prognosis were included in the final model: lactate dehydrogenase > upper limit of normal (ULN) [hazard ratio (HR) = 2.31], Eastern Cooperative Oncology Group performance status of 2 (HR = 2.19), presence of liver metastases (HR = 2.00), albumin ≤4 g/dl (HR = 1.54), alkaline phosphatase > ULN (HR = 1.38) and time from start of initial androgen-deprivation therapy to start of treatment ≤36 months (HR = 1.30). Patients were categorized into good (n = 369, 46%), intermediate (n = 321, 40%) and poor (n = 107, 13%) prognosis groups based on the number of risk factors and relative HRs. The C-index was 0.70 ± 0.014. The model was validated by the external dataset (n = 286).

Conclusion

This analysis identified six factors used to model survival in mCRPC and categorized patients into three distinct risk groups. Prognostic stratification with this model could assist clinical practice decisions for follow-up and monitoring, and may aid in clinical trial design.

Trial registration numbers

NCT00638690.

Effect of pantoprazole to enhance activity of docetaxel against human tumour xenografts by inhibiting autophagy

BACKGROUND

Autophagy allows recycling of cellular components and may facilitate cell survival after chemotherapy. Pantoprazole inhibits proton pumps and is reported to inhibit autophagy. Here we evaluate the effects of pantoprazole to modify cytotoxicity of the anticancer drug docetaxel, and underlying mechanisms.

METHODS

Effects of docetaxel±pantoprazole were studied against wild-type and autophagy-deficient PC3 cells and against four human xenografts. Effects of pantoprazole on autophagy were evaluated by quantifying LC3-I, LC3-II and p62 proteins in western blots, and by fluorescent microscopy of cells transfected with RFP-GFP-LC3. The distribution of drug effects and of autophagy was quantified in tumour sections in relation to blood vessels and hypoxia by immunohistochemistry using γH2AX, cleaved caspase-3, Ki67 and LC3/ p62.

RESULTS

Pantoprazole increased the toxicity of docetaxel in vitro, increased docetaxel-induced expression of γH2AX and cleaved caspase-3, and decreased Ki67 in tumour sections. Pantoprazole increased growth delay of four human xenografts of low, moderate and high sensitivity to docetaxel, with minimal increase in toxicity. Docetaxel led to increased autophagy throughout tumour sections. Pantoprazole inhibited autophagy, and effects of pantoprazole were reduced against genetically modified cells with decreased ability to undergo autophagy.

CONCLUSIONS

Autophagy is a mechanism of resistance to docetaxel chemotherapy that may be modified by pantoprazole to improve therapeutic index.

Clinical variables associated with PSA response to abiraterone acetate in patients with metastatic castration-resistant prostate cancer

BACKGROUND

Abiraterone acetate (abiraterone) prolongs overall survival (OS) in patients with metastatic castration-resistant prostate cancer (mCRPC). This study's objective was to retrospectively identify factors associated with prostate-specific antigen (PSA) response to abiraterone and validate them in an independent cohort. We hypothesized that the neutrophil/lymphocyte ratio (NLR), thought to be an indirect manifestation of tumor-promoting inflammation, may be associated with response to abiraterone.

PATIENTS AND METHODS

All patients receiving abiraterone at the Princess Margaret (PM) Cancer Centre up to March 2013 were reviewed. The primary end point was confirmed PSA response defined as PSA decline ≥50% below baseline maintained for ≥3 weeks. Potential factors associated with PSA response were analyzed using univariate and multivariable analyses to generate a score, which was then evaluated in an independent cohort from Royal Marsden (RM) NHS foundation.

RESULTS

A confirmed PSA response was observed in 44 out of 108 assessable patients (41%, 95% confidence interval 31%-50%). In univariate analysis, lower pre-abiraterone baseline levels of lactate dehydrogenase, an NLR ≤ 5 and restricted metastatic spread to either bone or lymph nodes were each associated with PSA response. In multivariable analysis, only low NLR and restricted metastatic spread remained statistically significant. A score derived as the sum of these two categorical variables was associated with response to abiraterone (P = 0.007). Logistic regression analysis on an independent validation cohort of 245 patients verified that this score was associated with response to abiraterone (P = 0.003). It was also associated with OS in an exploratory analysis.

CONCLUSIONS

A composite score of baseline NLR and extent of metastatic spread is associated with PSA response to abiraterone and OS. Our data may help understand the role of systemic inflammation in mCRPC and warrant further research.

Translating clinical trials to clinical practice: outcomes of men with metastatic castration resistant prostate cancer treated with docetaxel and prednisone in and out of clinical trials

BACKGROUND

Multiple factors can influence outcomes of patients receiving identical interventions in clinical trials and in routine practice. Here, we compare outcomes of men with metastatic castrate-resistant prostate cancer (mCRPC) treated with docetaxel and prednisone in routine practice and in clinical trials.

PATIENTS AND METHODS

We reviewed patients with mCRPC treated with docetaxel at Princess Margaret Cancer Centre. Primary outcomes were overall survival and PSA response rate. Secondary outcomes were reasons for discontinuation and febrile neutropenia. Outcomes were compared for men treated in routine practice and in clinical trials, and with data from the TAX 327 study.

RESULTS

From 2001 to 2011, 438 men were treated, of whom 357 received 3-weekly docetaxel as first-line chemotherapy: 314 in routine practice and 43 in clinical trials. Trial patients were younger and had better performance status. Median survival was 13.6 months [95% confidence interval (95% CI) 12.1-15.1 months] in routine practice and 20.4 months (95% CI 17.4-23.4 months, P = 0.007) within clinical trials, compared with 19.3 months (95% CI 17.6-21.3 months, P < 0.001) in the TAX 327 study. PSA response rates were 45%, 54%, and 53%, respectively (P = NS). Reasons for treatment discontinuation were similar although trial patients received more cycles (median: 6 versus 8 versus 9.5, P < 0.001). Rates of febrile neutropenia were 9.6, 0, and 3% (P < 0.001) while rates of death within 30 days of last dose were 4%, 0%, and 3%, respectively (P = NS).

CONCLUSIONS

Survival of patients with mCRPC treated with docetaxel in routine practice is shorter than for men included in trials and is associated with more toxicity.

Targeting the androgen receptor in the management of castration-resistant prostate cancer: rationale, progress, and future directions

Since the year 2000, tremendous progress has been made in the understanding of castration-resistant prostate cancer (crpc), a disease state now recognized to retain androgen receptor (ar)-dependency in most cases. That understanding led to the rational design of novel therapeutic agents targeting hormonal pathways in metastatic crpc. Two new drugs-the CYP17 inhibitor abiraterone acetate and the potent ar antagonist enzalutamide-were recently shown to prolong overall survival after chemotherapy treatment in patients with metastatic disease, with the former agent also demonstrating impressive activity in the pre-chemotherapy setting. Other new drugs targeting the ar-as well as drugs targeting heat shock proteins that protect cytoplasmic ar from degradation-are currently undergoing clinical development.This review briefly describes the molecular mechanisms underlying castration resistance and hormonal dependence in prostate tumours and summarizes the current ongoing and completed clinical trials that are targeting hormonal pathways in metastatic crpc. Potential mechanisms of resistance to these novel hormonal agents are reviewed. Finally, future research directions, including questions about drug sequencing and combination, are discussed.

Melanoma prevention: are we doing enough? A Canadian perspective

Melanoma is the most dangerous form of skin cancer, and its incidence is increasing significantly among Canadians. In parallel with the rising incidence and morbidity, the financial burden caused by this disease will continue to increase dramatically for the government and for individuals alike. More concerted effort to raise awareness of melanoma in Canada is therefore needed.Risk factors-such as family history, childhood sunburn exposure, and age-play a significant role in an individual's likelihood to develop melanoma. Ultraviolet radiation exposure is the most modifiable variable in melanoma causation. It is therefore important for the general public, in particular the country's youth, to understand the consequences of lifestyle choices-especially tanning bed use and "sun worshipping." Many of these issues are not being addressed fully at either the national or the provincial level, with Canadian efforts trailing those of other nations facing similar challenges. Canada also has workforce issues, with an inadequate distribution and number of physicians who can detect and treat melanoma at an early curative stage. With proper education and public awareness, melanoma prevention can be an achievable goal in Canada.

Topographical analysis of telomere length and correlation with genomic instability in whole mount prostatectomies

BACKGROUND

Many critical events in prostatic carcinogenesis appear to relate to the emergence of genomic instability. Characteristic genomic abnormalities such as 8p loss, 8q gain, trisomy 7, and PTEN microdeletions may provide selective advantages to increase neoplastic transformation. Evidence suggests that telomere dysfunction is a plausible mechanism for some of these abnormalities on the basis of the break-fusion-bridge cycle that can lead to manifestations of genomic instability.

METHODS

In this study, we correlate telomere length measured by quantitative FISH in various prostatic histologies with markers of genomic instability and immunohistochemical measures of proliferation and oxidative stress.

RESULTS

We find that telomere shortening is correlated with abnormalities on chromosome 8, but not with trisomy 7 or abnormalities of the PTEN locus. There are associations with C-MYC aberrations in stroma with greater proximity to cancer and a correlation between telomere length in a number of prostatic histologies and the adjacent stroma, suggesting the importance of microenvironmental effects on telomere maintenance in the prostate. This finding was also supported by the finding of the correlation between telomere attrition and the levels of oxidative stress as measured by malondialdehyde staining in HPIN lesions close to cancer.

CONCLUSIONS

Telomere attrition in the prostate gland is associated with particular genomic aberrations that contribute to the genomic instability characteristic of prostatic carcinogenesis. Correlations between various histologies and adjacent stroma telomere length suggest it is also may reveal microenvironmental effects within the prostate gland. Oxidative stress may contribute to telomere attrition in HPIN close to cancer.

Use of serum and tissue biomarker analysis embedded in a phase II clinical trial of cytarabine in castration-refractory prostate cancer to investigate prostate cancer biology

59

Background: Other than the androgen receptor, the TMPRSS2-ERG genomic aberrations in prostate cancer provide the first recent opportunity to target therapy in castration refractory prostate cancer (CRPC). We initiated a phase II clinical trial of cytarabine in docetaxel refractory CRPC on the basis of microarray, in vitro and case report evidence that cytarabine may be particularly effective in men harbouring abnormalities of the ERG oncogenes. Embedded in this clinical trial was the first use of blood mRNA levels of prostate cancer related genes as biomarkers of response and prognosis.

Methods: Patients with docetaxel refractory progressive CRPC received intravenous cytarabine at doses between 1g/m2-0.25 g/m2 q3 weekly. Responses were defined according to PCWG2C. 10 patients were enrolled between June 2007 and January 2010. TMPRSS2:ERG, PSA and PCA3 mRNA copies in whole blood collected with PAXgene tubes at the beginning of each cycle and at trial termination were quantified using transcription-mediated amplification assays. The prototype TMPRSS2:ERG assay detects the gene fusion isoform TMPRSS2 exon1 to ERG exon4.

Results: No patients demonstrated a serum PSA response (PCWG2C). The average number of cycles administered was 2.6. Significant toxicities including grade 3-4 thrombocytopenia (2) and grade 3-4 neutropenia (3). These toxicities necessitated several dose reductions in the protocol, however most patients were removed from trial for serum PSA progression alone. PCA3 and PSA mRNAs were detectable in 8/10 and 9/10 cases, respectively; there was no correlation between serum PSA and PCA3 or PSA mRNA copy levels in blood. Testing for TMPRSS2:ERG in blood was able to predict the presence or absence of the TMPRSS2-ERG rearrangement in 9/10 cases when compared to 3 colour FISH carried out on baseline biopsies/ prostatectomies (2/10 positive for Exon 4:Exon 1 deletion).

Conclusions: Cytarabine administation is ineffective in docetaxel refractory CRPC. Blood mRNA levels of prostate cancer genes reveal novel aspects of prostate cancer biology and have implications for the understanding of circulating tumour cells.

[Table: see text]

Topographical analysis of telomere length and correlation with genomic instability in whole mount prostatectomies

11107

Background: Many critical events in prostatic carcinogenesis appear to relate to the emergence of chromosomal instability and acquisition of genomic rearrangements. Characteristic abnormalities such as 8p loss, 8q gain, trisomy 7, PTEN microdeletions and TMPRSS2-ERG gene fusions appear to mediate mechanisms to increase neoplastic transformation in prostate cancer. Current evidence suggests that telomere dysfunction is a likely causative factor for some of these abnormalities on the basis of its relationship to mechanisms such as the break-fusion-bridge cycle that can lead to the onset of chromosomal instability. Methods: In this study, we correlated telomere length in various prostatic histologies by quantitative FISH with genomic markers of chromosomal instability by standard FISH and immunohistochemical measures of proliferation in 3 whole mount prostatectomies. Results: After analysing approximately 25,000 cells, we found that telomere shortening was correlated with an increase in the number of cells with abnormalities on chromosome 8, such as an increase in the average number of c-myc signals (r∼0.35, p∼0.02). However, there were no significant correlations with abnormalities such as trisomy 7 or abnormalities of the PTEN locus in any sample. Additional findings included; associations found with the probability of C-MYC aberrations in stroma with greater proximity to cancer (<1,000 um), a correlation between telomere length in a number of prostatic histologies (normal, atrophy, HPIN and cancer) with the adjacent stroma, and a lack of correlation between the Ki67 index of various histologies and their telomere length - all suggesting the importance of microenvironmental effects on telomere maintenance in the prostate. Finally, we also report significant telomere shortening in BPH in 2 cases, a phenomenon that has not been noted previously. Conclusions: This is the first study to directly link a mechanism of chromosomal instability with specific chromosomal abnormalities in prostatic carcinogenesis and also suggests that the microenvironmental milieu is of critical importance in the evolution of in vivo telomere homeostasis.

No significant financial relationships to disclose.

Telomere dysfunction in prostatic carcinogenesis

10021

Background: Telomeres are composed of tandemly repeated DNA sequences (TTAGGG) and specific binding proteins located at the ends of eukaryotic chromosomes. They stabilize chromosomal ends; telomere shortening is an important mechanism of genomic instability and can lead to end-to-end chromosomal fusion, rearrangements and cell death. Here we evaluate the hypothesis that telomere shortening contributes to the development of prostate cancer (CaP). Methods: We used telomeric, centromeric and chromosome specific peptide-nucleic acid probes with z-stacked quantitative fluorescence in-situ hybridisation analysis to initially analyse 15 radical prostatectomy specimens and then subsequently sextant core biopsies from 80 men obtained in 1998–2001 containing high-grade prostate intraepithelial neoplasia (HPIN) only. The biopsy cohort outcome is blinded to prevent experimental bias and has a minimum follow-up of 2 years with 41 men diagnosed subsequently with CaP and 39 men without CaP on rebiopsy. Regions of interest were identifying with an overlying haematoxylin and eosin slide. Results: We found a significant decrease in telomere length in both HPIN and CaP in comparison to normal prostatic epithelium accompanied by elevated rates of aneusomy. Telomere erosion in HPIN was more common in regions of the prostate-containing CaP. We now have analyzed ∼4000 cells of matching HPIN and surrounding stroma. Preliminary analysis demonstrated that the median telomere length in HPIN is approximately 27% of the surrounding stroma with upper and lower quartiles being 16% and 38% respectively. Logistic regression analysis is in progress to determine whether the length of the shortest telomeres or the average telomeric length in a sample predicts for subsequent diagnosis of CaP. Secondary analyses are examining the effect of telomere length on the interval to the diagnosis of CaP, the effect of age on telomere length and the eventual Gleason score. Conclusions: Analysis of telomere length holds great promise for developing improved prognostic markers in prostatic carcinogenesis. This is a first of its kind study in the field.

No significant financial relationships to disclose.

Detection of novel variant TMPRSS2 /ERG fusion transcripts suggests independent genomic alterations may underlie origin of multi-centric prostate cancer

10029

Background: Most of the early successes in identifying chromosomal translocations in neoplasias came from the study of hematological malignancies and sarcomas, with limited evidence that consistent genomic rearrangements were present in epithelial malignancies. Recently it was reported that ∼75% of prostate cancers carry a genomic rearrangement leading to fusion of the TMPRSS2 locus to either the ERG or ETV1 genes (both ETS transcription factors). In the fusion gene, the androgen-sensitive promoter elements of TMPRSS2 are thought to mediate over-expression of these ETS transcription factors. Over-activity of the ETS family of transcription factors has been suggested to be involved in the transition from pre-neoplasia to carcinoma as they regulate genes involved in processes such as adhesion, motility, invasion and angiogenesis. Methods: Using both RT-PCR and FISH with published primers and BACs respectively we analyzed 15 samples of prostatic carcinoma from radical prostatectomies and sequenced a subset of the TMPRSS2/ERG fusions. Results: We have found ERG-TMPRSS2 fusion transcripts in 6 samples and no ETV1-TMPRSS2 fusions. Of the 6 fusion tumours, 5 were Gleason 7 and 1 was Gleason 9. Tumour stages ranged from T2a-T3b. One sample with multi-centric carcinoma exhibited 2 distinct in-frame rearrangements generating novel TMPRSS2 /ERG fusion transcripts. Variant I TMPRSS2/ERG transcript was 430 bp and it led to fusion of exons 1 and 2 of the TMPRSS2 gene with exons 5 and 6 of the ERG gene. Variant II TMPRSS2/ERG fusion transcript was slightly smaller at 350 bp and it led to fusion of exon 1 of the TMPRSS2 gene to exons 5 and 6 of the ERG gene. These novel transcripts appear to be smaller than the published fusion proteins but preliminary analysis suggests that all known regulatory and functional protein domains are maintained. Conclusions: The demonstration of two new TMPRSS2/ERG variant fusion transcripts in prostate cancer deserves further study to evaluate their functional impact and prognostic and pathological importance. Moreover the presence of two distinct transcripts within a single multi-centric tumor provides genomic evidence that independent clonal neoplasms can arise synchronously in prostate cancer.

No significant financial relationships to disclose.

Weekly docetaxel as second line treatment after mitozantrone for androgen-independent prostate cancer

BACKGROUND

Two recent phase III trials have shown an improvement in survival with the use of docetaxel in metastatic androgen-independent prostate cancer (AIPC) compared to mitozantrone. However no phase II trials have clearly defined the level of activity of docetaxel after mitozantrone.

AIMS

We sought to define the activity and toxicity of weekly docetaxel as second line chemotherapy after mitozantrone in men with AIPC.

METHODS

Twenty men were treated with docetaxel 40 mg/m2 weekly for 3 of every 4 weeks until progression or prohibitive toxicity. End-points included prostate specific antigen response, common toxicity criteria, time to progression and overall survival.

RESULTS

Nine patients (45%) had a 50% or greater reduction in PSA maintained for at least 1 month. Weekly docetaxel was well tolerated with few major toxicities: two patients had Grade 3 diarrhoea (10%) and six had grade 2-4 haematologic toxicities (30%). The median time to progression was 5 months (range 0-13) and median survival was 13 months (range 1-24) from starting docetaxel. The median survival from starting mitozantrone was 19 months. Men who had responded to mitozantrone were no more likely to respond to docetaxel (P = 0.2 Fischer's exact test).

CONCLUSIONS

Weekly docetaxel is a safe and active second-line treatment after mitozantrone for androgen-resistant prostate cancer, with similar levels of activity to the first-line setting.

Smoking reduction does work: Resulting alterations in the incidence and histological subtypes of lung cancer in New South Wales in the last 20 years

BACKGROUND

There is irrefutable evidence of the association between lung cancer and smoking. The effects of public health campaigns to reduce population-smoking rates on the incidence and the histological distribution of lung cancer were examined.

METHODS

The data held in the New South Wales Cancer Registry from 1972 to 2001 was accessed.

RESULTS

The data revealed a decreasing incidence of lung cancer amongst males and a rate that continued to increase amongst females. Interestingly, there was also an effect on the histological distribution of lung cancers, with falling rates of small cell lung cancer and squamous cell cancer, both of which have a high association with smoking; and an increasing incidence of adenocarcinomas.

CONCLUSIONS

These trends reveal patterns seen worldwide. The increasing proportion of adenocarcinomas in particular may be related to the changing composition of cigarettes and filters.

Beauty is in the eye of the examiner: reaching agreement about physical signs and their value

Despite advances in other areas, evidence-based medicine is yet to make substantial inroads on the standard medical physical examination. We have reviewed the evidence about the accuracy and reliability of the physical examination and common clinical signs. The physical examination includes many signs of marginal accuracy and reproducibility. These may not be appreciated by clinicians and could adversely affect decisions about treatment and investigations or the teaching and examination of students and doctors-in-training. We provide a selected summary of the reliability and accuracy as well as important messages of key findings in the physical examination.

The use of taxanes in choriocarcinoma; a case report and review of the literature

BACKGROUND

Both preclinical data and case reports support the use of taxanes for high-risk metastatic choriocarcinoma.

CASE

We report the case of a 31-year-old with metastatic choriocarcinoma who required 3rd-line treatment with a paclitaxel-cisplatin-based regimen. She achieved a complete response and remains relapse-free 21 months after her last dose of chemotherapy.

CONCLUSION

The literature suggests that paclitaxel contributes significantly to the treatment of choriocarcinoma and its use should be explored further. This is the first case report formally reporting its combination with cisplatin.