Clinical Utility of Circulating Tumour Cell Androgen Receptor Splice Variant-7 Status in Metastatic Castration-resistant Prostate Cancer.

Abstract Background Detection of androgen receptor splice variant-7 (AR-V7) mRNA in circulating tumour cells (CTCs) is associated with worse outcome in metastatic castration-resistant prostate cancer (mCRPC). However, studies rarely report comparisons with CTC counts and biopsy AR-V7 protein expression. Objective To determine the reproducibility of AdnaTest CTC AR-V7 testing, and associations with clinical characteristics, CellSearch CTC counts, tumour biopsy AR-V7 protein expression and overall survival (OS). Design, setting, and participants CTC AR-V7 status was determined for 227 peripheral blood samples, from 181 mCRPC patients with CTC counts (202 samples; 136 patients) and matched mCRPC biopsies (65 samples; 58 patients). Outcome measurements and statistical analysis CTC AR-V7 status was associated with clinical characteristics, CTC counts, and tissue biopsy AR-V7 protein expression. The association of CTC AR-V7 status and other baseline variables with OS was determined. Results and limitations Of the samples, 35% were CTC+/AR-V7+. CTC+/AR-V7+ samples had higher CellSearch CTC counts (median CTC; interquartile range [IQR]: 60, 19–184 vs 9, 2–64; Mann-Whitney test p Conclusions Studies reporting the prognostic relevance of CTC AR-V7 status must account for CTC counts. Discordant CTC AR-V7 results and AR-V7 protein expression in matched, same-patient biopsies are reported. Patient summary Liquid biopsies that determine circulating tumour cell androgen receptor splice variant-7 status have the potential to impact treatment decisions in metastatic castration-resistant prostate cancer patients. Robust clinical qualification of these assays is required before their routine use

5-Fluorouracil degradation rate could predict toxicity in stages II-III colorectal cancer patients undergoing adjuvant FOLFOX

5-Fluorouracil is commonly used for gastrointestinal cancer treatment in an adjuvant setting; however, the toxicity can lead to a reduction, delay, or discontinuation of treatment. We retrospectively investigated the association between the 5-fluorouracil degradation rate (5-FUDR) and genetic polymorphisms of TSER, DPYD, and MHTFR with toxicity in colorectal cancer patients treated with adjuvant FOLFOX. Pretreatment 5-FUDR and MTHFR A1298T or C677T, TSER, and DPYD gene polymorphisms were characterized in stages II-III colorectal cancer patients. Patients were classified into three metabolic classes according to the 5-FUDR value. Association with toxicities was evaluated retrospectively using logistic regression analysis. Overall, 126 patients were selected (35 women, 91 men). Seven patients were poor metabolizers, 116 patients were normal metabolizers, and three patients were ultra-rapid metabolizers. The median 5-FUDR was 1.53 ng/ml/10 cells/min (range: 0.42-2.57 ng/ml/10 cells/min). Severe, rate-limiting toxicities (grades 3-4) were encountered in 22.2% of patients. No associations between MTHFR or TSER polymorphisms and toxicity were detected, whereas 5-FUDR showed a statistically significant association with toxicity (P=0.0047). The DPYD heterozygous mutation was detected in only one patient, who showed grade 4 hematological toxicity and a lower 5-FUDR value. The 5-FUDR value seems not to be affected by MTHFR and TSER polymorphisms. Compared with the available pharmacogenomics tests, the pretreatment evaluation of 5-FUDR increases the proportion of identified colorectal patients at high risk for severe toxicity. Thus, it appears to be a suitable pretreatment toxicity biomarker in a subgroup of patients in whom dose-intensity maintenance is the key factor

A nomogram to predict 5-fluorouracil toxicity: when pharmacogenomics meets the patient

Fluoropyrimidines combined with other agents are commonly used for gastrointestinal cancer treatment. Considering that severe toxicities occur in 30% of patients, we aimed to structure a nomogram to predict toxicity, based on metabolic parameter and patients' characteristics. We retrospectively enrolled patients affected by gastrointestinal tract cancers. Pretreatment 5-fluorouracil (5-FU) degradation rate and DPYD, TSER, MTHFR A1298T, and C677T gene polymorphisms were characterized. Data on toxicities were collected according to CTCAE v3.0. Multivariate logistic regression analysis was used to structure a nomogram. 642 patients were enrolled (384 men; 258 female; median age: 67 years, range: 27-87): 449 (69.9%) patients were affected by colorectal cancer; 118 (18.4%) by gastroesophageal cancer; 66 (10.3%) by pancreatic cancer; and nine (1.4%) by other cancers. Grade 3-4 toxicities were observed in 118 (18.4%) patients and were most frequently observed in patients with altered 5-FU degradation rate (43.5 and 26.7% of the patients in the poor metabolizer and in the ultrarapid metabolizer group respectively, vs. 17% in the normal metabolizer group) and in DPYD heterozygous mutated patients (83.3% of the patients). Age, DPYD status, the number of drugs administered, and 5-FU degradation rate value were associated to severe toxicities. On the basis of these findings, we structured a nomogram to assess a score to predict the risk of developing severe toxicity. Compared with the available pharmacogenetic tests, this approach can be applied to the whole population, predicting the risk for severe toxicity, with an easy, low-cost, and not invasive technique