Amplification of ERBB2 (HER2) in embryonal rhabdomyosarcoma: A potential treatment target in rare cases?

The ERBB2 gene encodes a receptor tyrosine kinase also known as HER2. The gene is amplified and overexpressed in one-fifth of breast carcinomas; patients with such tumors benefit from targeted treatment with trastuzumab or other drugs blocking the receptor. In addition, ERBB2 has been shown to be amplified and/or overexpressed in a variety of other malignancies. Notably, both alveolar and embryonal rhabdomyosarcoma (RMS), especially in children, often show increased expression of ERBB2. Although high-level amplification of the gene has not been described in RMS, its frequent expression at the cell surface of RMS cells has been exploited for chimeric antigen receptor T-cell (CAR T)-based treatment strategies. We here describe two cases of pediatric, fusion-negative embryonal RMS with high-level amplification of the ERBB2 gene. One patient is currently treated with conventional chemotherapy for a recently detected standard risk RMS, whereas the other patient died from metastatic disease. Both tumors displayed focal amplicons (210 and 274 Kb, respectively) in chromosome band 17q12, with proximal and distal borders corresponding to those typically seen in breast cancer. In both tumors, the ERBB2 amplicon correlated with high expression at the RNA and protein levels. Thus, breast cancer-like ERBB2 amplification is a very rare, but recurrent feature of pediatric RMS, and should be exploited as an alternative treatment target.     

PAIN VARIATIONS DURING CANCER TREATMENT IN CHILDREN: A Descriptive Survey

Structured interviews were conducted with 66 children and their families to investigate how the experience of pain varied during cancer treatment. At diagnosis, 49% experienced cancer-related pain. Intense pain was more common at the beginning of treatment when it was often believed that pain treatment could be better. Procedure- and treatment-related pain were the major problems initially. Procedural pain gradually decreased, but treatment-related pain was constant and dominating. For some procedures pain was rated highest initially, lower during the second period, and higher again during the final part of treatment. Pain intensity measurement was seldom performed, and parents increasingly considered themselves better judges of their child's pain than professionals. Increased knowledge about pain and pain treatment in children with cancer, where most pain is iatrogenic, will help us to meet the needs and demands of children and parents, and to reduce pain to a minimum.     

Spotlight on NKG2C and the human NK‐cell response to CMV infection

Immune responses to cytomegalovirus (CMV) infection in the mouse and human involve the expansion of specific subsets of natural killer (NK) cells with specific phenotypic characteristics and a heightened ability to produce interferon (IFN)‐gamma. In humans, these NK‐cell responses are largely driven by the activating receptor NKG2C, which recognize human leukocyte antigen (HLA)‐E in complex with leader sequence peptides. In this issue of the European Journal of Immunology, Noyola et al. [Eur. J. Immunol. 2012, 42: 3256‐3266] examine NK‐cell responses in a unique cohort of young children with asymptomatic and symptomatic congenital CMV infection. They also address NK‐cell responses to CMV in relation to NKG2C gene copy number. Children with a symptomatic congenital infection exhibited a marked expansion of NKG2C⁺ NK cells. However, despite having slightly lower frequencies of NKG2C⁺ NK cells, children with a heterozygous deletion of the NKG2C gene seemed to control the virus as efficiently as those with two copies of the NKG2C gene. The present studies shed new light on the role of NKG2C copy number variation on the human NK‐cell response to CMV infection.     

A genome-wide association scan on estrogen receptor-negative breast cancer

Introduction

Breast cancer is a heterogeneous disease and may be characterized on the basis of whether estrogen receptors (ER) are expressed in the tumour cells. ER status of breast cancer is important clinically, and is used both as a prognostic indicator and treatment predictor. In this study, we focused on identifying genetic markers associated with ER-negative breast cancer risk.

Methods

We conducted a genome-wide association analysis of 285,984 single nucleotide polymorphisms (SNPs) genotyped in 617 ER-negative breast cancer cases and 4,583 controls. We also conducted a genome-wide pathway analysis on the discovery dataset using permutation-based tests on pre-defined pathways. The extent of shared polygenic variation between ER-negative and ER-positive breast cancers was assessed by relating risk scores, derived using ER-positive breast cancer samples, to disease state in independent, ER-negative breast cancer cases.

Results

Association with ER-negative breast cancer was not validated for any of the five most strongly associated SNPs followed up in independent studies (1,011 ER-negative breast cancer cases, 7,604 controls). However, an excess of small P-values for SNPs with known regulatory functions in cancer-related pathways was found (global P = 0.052). We found no evidence to suggest that ER-negative breast cancer shares a polygenic basis to disease with ER-positive breast cancer.

Conclusions

ER-negative breast cancer is a distinct breast cancer subtype that merits independent analyses. Given the clinical importance of this phenotype and the likelihood that genetic effect sizes are small, greater sample sizes and further studies are required to understand the etiology of ER-negative breast cancers.