A novel capillary nano-immunoassay for assessing androgen receptor splice variant 7 in plasma. Correlation with CD133 antigen expression in circulating tumor cells. A pilot study in prostate cancer patients.

PURPOSE: Androgen receptor (AR) splice variant 7 (AR-V7) has been related with both a higher risk of prostate cancer (PC) progression and differential responsiveness to hormonal agents versus chemotherapy. The objective of this study was to investigate the feasibility of a novel capillary nano-immunoassay in assessing AR-V7 in plasma from PC patients. METHODS: Patients with either localized or advanced PC were included in the study. Assessment of AR-V7 in plasma was performed through a capillary nano-immunoassay platform. Correlation with clinical data, stem cell biomarkers (such as CD133+), AR amplification and PTEN status was identified. RESULTS: The study included 72 PC patients. AR-V7 signal was detected in 21 (29%) patients: 17 (81%) had a Gleason score ≥7, 15 (71%) castration-resistant prostate cancer (CRPC), 18 (86%) metastatic disease and PSA (median) high than AR-V7 negative (p < 0.05). CD133 was expressed in 69 (96%) patients. The median CD133+ expression in circulating tumor cells CTCs was higher among the 21 AR-V7 positive cases versus AR-V7 negative (7 vs. 3). Androgen Receptor and PTEN fluorescence in situ hybridization (FISH) on CD133+ captured cells were performed: 37 cases showed ≥four CD133+ CTCs, of which 81% showed an increased AR copy number. This percentage was similar in both AR-V7-positive and AR-V7-negative patients. A total of 68% of the cases showed deletion of PTEN: 70% were ARV-7 positive vs. 67%, which were AR-V7 negative. CONCLUSIONS: Assessing the presence of AR-V7 in plasma from PC patients is feasible by a novel capillary nano-immunoassay. AR-V7 was observed in 29% of the tumors and is more frequent in aggressive tumors.

Epidermal growth factor receptor (EGFR) pathway polymorphisms as predictive markers of cetuximab toxicity in locally advanced head and neck squamous cell carcinoma (HNSCC) in a Spanish population.

OBJECTIVES: To examine the relationship between polymorphisms of the epidermal growth factor receptor (EGFR) pathway and toxicity in head and neck squamous cell carcinoma (HNSCC) patients treated with cetuximab. MATERIAL AND METHODS: Multicenter, retrospective, observational pilot study which included 110 patients with histologically-confirmed human papillomavirus (HPV) negative HNSCC in locally advanced stages (III-IVA-B) and who were treated with chemotherapy and radiotherapy plus cetuximab between 2003 and 2013. Genetic analyses for single nucleotide polymorphisms (SNP) in genes EGFR, CCDN1, FCGR2A, FCGR3A and KRAS-LCS6 were performed though available allelic discrimination assay and/or polymerase chain reaction-restriction fragment length polymorphism methods. RESULTS: Acneiform rash was observed in 55.5% of patients, dry skin in 45.5% and pruritus in 20.9%. A significant association with dry skin and global cetuximab-related toxicity was observed for the KRAS-LCS6 (rs61764370) variant (p<0.05); carriers of the G allele (genotypes TG+GG) in the dominant model were observed to have a decreased susceptibility of developing dry skin (OR=0.287 [95%CI=0.119-0.695]). Carriers of the A (GA+AA) allele for EGFR (rs2227983) showed a decreased risk of suffering from pruritus (OR=0.345 [0.124-0.958]). Similarly, KRAS (rs1801274) was related with lower global cetuximab-related toxicity (OR=0.266 [0.114-0.622]). CONCLUSION: This pilot study provides preliminary evidence supporting genetic variation of EGFR (rs2227983), KRAS (rs61764370) and FCGR2A (rs180127) as useful biomarkers for predicting reduced skin toxicity in HNSCC patients treated with a cetuximab-based therapy. Alternative therapeutic options should be explored for these patients.

Epidemiological characteristics of a Spanish cohort of patients diagnosed with squamous cell carcinoma of head and neck: distribution of risk factors by tumor location.

PURPOSE: Head and neck cancer is a highly heterogeneous disease comprising a large number of tumors located in the cervicofacial area. This study aimed to determine the epidemiological characteristics of squamous-cell carcinomas of the head and neck in the Spanish population, and the distribution of risk factors based on tumor locations. METHODS/PATIENTS: A cohort of 459 patients (75 oral cavity, 167 oro-/hypopharyngeal and 217 laryngeal cancers) recruited in 19 hospitals participating in the Spanish head and neck cancer cooperative group were included over 3 years (2012-2014). Epidemiological parameters and risk factors were obtained from a self-administered questionnaire, and tumor characteristics were obtained from clinical records. Multivariate multinomial logistic regression was used to assess factors associated with tumor location. RESULTS: Most patients were males (88.4 %), smokers (95 %) and drinkers (76.5 %). Relative to laryngeal cancer, pharyngeal cancer and oral cancer were more common in women than men (OR 3.58, p = 0.003 and 4.33, p = 0.001, respectively); pharyngeal cancer was more associated with rural environment (OR 1.81, p = 0.007) and weekly alcohol intake (10-140 g: OR 2.53, p = 0.012; 141-280 g: OR 2.47, p = 0.023; >280 g: OR 3.20, p = 0.001) and less associated with pack-years of smoking (21-40 packs: OR 0.46, p = 0.045; 41-70 packs: OR 0.43, p = 0.023; ≥71 packs: OR 3.20, p = 0.015). CONCLUSIONS: The distribution of these tumors differs between the sexes, with a higher proportion of oral cavity and pharyngeal tumors in women than in men. Oro-/hypopharyngeal cancers were more strongly associated with rural areas and with alcohol consumption, although less strongly associated with smoking than laryngeal tumors.