Prevalence of ARV7 in Asian metastatic castrate-resistant prostate cancer (mCRPC) patients using multiple detection platforms

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Background: The presence of AR-V7 in metastatic castrate resistant prostate cancer (mCRPC) men has been associated with worse outcome in men initiated on 2nd generation androgen receptor signalling inhibitors (ARSI) in the Caucasian population. A multinational study was conducted to investigate this in the Asian population. Methods: mCRPC patients were recruited prospectively across 5 countries. Blood samples were collected and processed from patients with progressive disease immediately before the initiation of a new treatment and at progression. AR-V7 detection were performed using 3 methods: CTC enrichment followed by automated immunofluorescent staining (Clearbridge [CB]), CTC enrichment followed by reverse-transcription PCR analysis (IBN), and the AdnaTest Prostate Cancer(Adna) platform for CTC analysis and detection. Only blood samples collected in Singapore underwent all 3 methods of detecting AR-V7. Comparison of AR-V7 prevalence using the 3 detection methods were done on patients with the AdnaTest platform as gold standard. We examined associations between AR-V7 status and PSA response rates, PSA progression free survival and overall survival(OS). Results: 102 patients were recruited. 72 patients had ARSi while 30 patients had chemotherapy. 66 patients were included for the comparison of AR-V7 detection methods. AR-V7 prevalence rate was 14.3% (95% CI 4.8-30.3), 21.6% (95% CI 12.9-32.7) and 33.7% (95% CI 24.6-43.8) based on Adna, CB and IBN respectively. Concordance between Adna and CB was 75% while Adna and IBN was 68%. AR-V7- patients had a trend towards higher PSA response, lower risk of PSA progression as compared to AR-V7+ patients. AR-V7- patients had a significantly lower risk of death as compared to AR-V7+ patients detected by Adna and IBN platforms but not the CB platform. The association between ARV7 status and outcomes did not vary when compared across treatment groups. Conclusions: AR-V7 positivity in Asian mCRPC patients is consistent with the data reported in Western populations with lower PSA response rates, PSA progression free survival and OS. This data suggest that ARV7 is more likely a prognostic than a predictive biomarker. Clinical trial information: 2015/2797.

AR-V7 in Asian patients with metastatic CRPC: A multinational, multicentre study

TPS401

Background: The detection of androgen-receptor splice variant 7 (AR-V7) mRNA transcript in circulating tumor cells (CTCs) of progressive metastatic castration-resistant prostate cancer (mCRPC) patients is associated with resistance to abiraterone and enzalutamide. This finding was validated by other studies that found no association between the presence of AR-V7 transcripts and response to both docetaxel and cabazitaxel. The results suggest that AR-V7 could represent a biomarker to guide treatment selection in mCRPC. However, data in Asian population is limited. This multinational study aims to prospectively investigate the incidence and prevalence of ARV7 in Asian mCRPC patients. This is also the first study to evaluate 3 different detection platforms and help provide guidance on which will be the best platform to carry forward in terms of clinical utility. Methods: 101 Asian subjects with histologically confirmed mCRPC whom are going to be treated with AR-directed therapies (abiraterone, enzalutamide) or taxane chemotherapy (docetaxel) will be enrolled from Singapore, Malaysia, Thailand, Hong Kong and Japan. Subjects will be excluded if they plan to receive additional concurrent anticancer therapies. Peripheral-blood samples will be obtained at baseline and at the time of progression. We will use 3 methods to analyse the samples: (i) CTC enrichment platform followed by automated immunofluorescent staining for DNA, cytokeratins, CD45 (lymphocyte common antigen), and AR-V7; (ii) CTC enrichment platform followed by reverse-transcription polymerase chain reaction analysis; and (iii) the AdnaTest platform for molecular characterization of CTCs. Subjects will be followed up to 2 years. The clinical outcomes of AR-V7-positive and AR-V7-negative patients will be compared. PSA response rates will be compared using the Fisher exact test. Time-to-event outcomes (PFS, OS) will be evaluated using Kaplan-Meier analysis, and survival time differences will be compared using log-rank test. Cox regression analyses will be used to assess the effect of AR-V7 status in predicting clinical outcomes. The study is in progress; 32 of 101 planned patients have been enrolled at the end of September 2017.

Cystic echinococcosis of livestock and humans in central Sudan

New information was collected on cystic echinococcosis in livestock (camels, cattle and sheep) and humans in the central region of Sudan. The livestock data were collected in abattoir-based surveys in the towns of Omdurman, Tamboul and Wad Madani, between 1998 and 2001, and covered a total of 8205 animals. The highest prevalence of infection was found in the camels (44.6% of 242 infected), followed by the sheep (6.9% of 5595) and cattle (3.0% of 2368). Records were made of the sizes of the 1320 hydatid cysts detected in the livestock (907 in sheep, 71 in cattle, and 342 in camels), whether or not each cyst was fertile, and where it occurred in the body of the host. Cysts collected from cattle and camels where much more likely to be fertile (22% and 24%, respectively) than those from sheep (1%). Camels and cattle therefore appear to be the principal intermediate hosts for Echinococcus granulosus in central Sudan, whereas sheep apparently play a marginal role in transmission. In 2002, as a preliminary assessment of the public-health impact of the disease, 300 residents of a rural village 60 km west of Wad Madani were surveyed using a portable ultrasound scanner. Only one (0.33%) of the villagers investigated was found infected. The implications of these finding are discussed in terms of the various strains of E. granulosus and the role of each in human disease.

The Marrara syndrome: a hypersensitivity reaction of the upper respiratory tract and buccopharyngeal mucosa to nymphs of Linguatula serrata

The Marrara syndrome, like Halazoun in Lebanon, is a hypersensitivity reaction of the upper respiratory tract and buccopharyngeal mucosa to nymphs of Linguatula serrata. The condition follows the consumption of Marrara which consists of raw liver, lungs, trachea and rumen of goats and sheep infected with larvae of L. serrata. The adult worm is found in the nasal passages of dogs. Sheep and goats are infected by eggs from infected dogs. A survey that included 240 adult individuals in a village of endemic L. serrata infection in the Sudan showed that 20% experienced symptoms of allergic nasopharyngitis (Marrara syndrome) following the consumption of raw viscera of goats or sheep at least once in their life. In a prospective study of 24 patients who reported to hospital with the Marrara syndrome, the clinical features included itching in the throat and nose, unilateral conductive deafness, tinnitus and facial palsy. Secondary bacterial infection caused suppurative otitis media. Adult L. serrata parasites were found in the nasal passages of 56 and 47% of male and female dogs in the endemic area. Nymphs were recovered from the mesenteric lymph nodes, lungs and livers of goats in the area.

Experimental transmission of hydatid infection from camels and cattle to dogs

Experimental transmission of hydatid infection was attempted by feeding viable cysts from camels and cattle to dogs. The infection was established in dogs with variable numbers of adult worms being recovered at the end of the experiment. Cats were entirely refractory to experimental infections.

Echinococcus granulosus infection in dogs in Tambool, Sudan

In the Tambool area (Central eastern Sudan) a survey was made of the infection rate of Echinococcus granulosus in dogs. From the total of 49 dogs shot by the police authority, 25 (51%) had E. granulosus in their intestines. The range of worm recovery was 7 to 28,400. These high infection and recovery rates could be explained by the rate of infection in the intermediate host (camel) slaughtered in the area.

Efficacy of fenbendazole against adult Dictyocaulus viviparus in experimentally infected calves

Fenbendazole, methyl-5(phenylthio)-2-benzimidazolecarbamate, a new broad-spectrum anthelmintic, was evaluated against the adult Dictyocaulus viviparus, lungworm of cattle, in artificially infected calves. At a dosage of 5 mg/kg of body weight, fenbendazole removed 100% of the worms if given as an oral suspension, and 99.7% of the worms if given as a feed additive.