Ultra-selection of metastatic colorectal cancer patients using next-generation sequencing to improve clinical efficacy of anti-EGFR therapy

BACKGROUND

Extended RAS analysis is mandatory in metastatic colorectal cancer (mCRC) patients. The optimal threshold of RAS mutated subclones to identify patients most likely to benefit from antiepidermal growth factor receptor (EGFR) therapy is controversial. Our aim was to assess the clinical impact of detecting mutations in RAS, BRAF, PIK3CA and EGFRS492R in basal tissue tumour samples by using a highly sensitive next-generation sequencing (NGS) technology in mCRC patients treated with chemotherapy plus anti-EGFR or anti-vascular endothelial growth factor.

PATIENTS AND METHODS

Five hundred and eighty-one tumour samples from untreated mCRC patients from 7 clinical studies were collected. Mutational analysis was carried out by standard-of-care (therascreen pyro) with a sensitivity detection of 5% mutant allele fraction (MAF), and compared with NGS technology using 454GS Junior platform (Roche Applied Science, Germany) with a sensitivity of 1%. Molecular results were correlated with clinical outcomes.

RESULTS

After quality assessment, 380 samples were evaluable for molecular analysis. Standard-of-care mutational analysis detected RAS, BRAFV600E or PIK3CA mutations in 56.05% of samples compared with 69.21% by NGS (P = 0.00018). NGS identified coexistence of multiple low-frequency mutant alleles in 96 of the 263 mutated cases (36.5%; range 2-7). Response rate (RR), progression-free survival (PFS) and overall survival (OS) were increasingly improved in patients with RAS wild-type, RAS/BRAF wild-type or quadruple (KRAS/NRAS/BRAF/PIK3CA) wild-type tumours treated with anti-EGFR, assessed by standard-of-care. No additional benefit in RR, PFS or OS was observed by increasing the detection threshold to 1% by NGS. An inverse correlation between the MAF of the most prevalent mutation detected by NGS and anti-EGFR response was observed (P = 0.039). EGFRS492Rmutation was not detected in untreated samples.

CONCLUSIONS

No improvement in the selection of patients for anti-EGFR therapy was obtained by adjusting the mutation detection threshold in tissue samples from 5% to 1% MAF. Response to anti-EGFR was significantly better in patients with quadruple wild-type tumours.

Dog assisted therapy for teenagers with emotional and behavioural issues: A multicentre study

Introduction

Further research is still needed to demonstrate the benefits of animal-assisted therapy (AAT) for specific participant profiles, such as children with behavioural disorders.

Objectives

We wanted to find out if AAT could be considered an efficient therapeutic strategy for the treatment of children with behavioural disorders.

Aims

We wanted to study the effects of a preestablished AAT program on the behaviour of children with emotional and behavioural issues in 6 different reception centres for children under government guardianship.

Methods

Forty-five children (12 to 17 years old) with emotional and behavioural issues participated in a 14-session AAT program. Behavioural measures were those routinely scored as part of therapy; an observational report of 3 different problematic behaviours (such as impulsivity, lack of social skills or lack of personal recognition) was made twice a week for each child (with a score of frequency and intensity). A pre- and post-treatment “global behaviour score” was calculated for each child, as an average value of the 3 problematic behaviours measured during the month pre-treatment and the month post-treatment.

Results

The 45 participants attended, on average, 72.8% of AAT sessions. Independent behaviour scores differed between the pre- and post-intervention evaluations (n = 135 behaviours) (Wilcoxon test; P < 0.0001). Based on the global behaviour score for each child (n = 45), significant change was found between pre- and post-intervention evaluations (Wilcoxon test; P = 0.0011).

Conclusions

Our results suggest AAT could be a beneficial intervention for children with behavioural issues in terms of program adherence and behaviour improvement.

Disclosure of interest

The authors have not supplied their declaration of competing interest.