Comparison of the sensitivity of mammography, ultrasound, magnetic resonance imaging and combinations of these imaging modalities for the detection of small (≤2 cm) breast cancer.

ABSTRACT: The aim of this study was to compare the sensitivity of mammography (MG), ultrasound (US), magnetic resonance imaging (MRI), and combinations of these imaging modalities for the detection of small (≤2 cm) breast cancer and to evaluate the benefit of preoperative breast MRI after performing conventional imaging techniques for small breast cancer.This was an observational retrospective review of 475 patients with pathologically confirmed breast cancer. We reviewed the medical records; assessed the preoperative reports of MG, US, and MRI; and categorized them as benign features (BI-RADS 1-3) or malignant features (BI-RADS 4 or 5). The criterion standard for detection was the pathologic assessment of the surgical specimen. The sensitivities of the different techniques were compared using the McNemar test.Among the 475 women, the sensitivity of MG was significantly greater in patients with low breast density than in those with high breast density (84.5% vs 65.8%, P < .001). US had higher sensitivity than MG (P < .001), and the combination of MG + US showed better sensitivity than MG or US alone (P < .001). Further addition of MRI to the combination of MG and US statistically contributed to the sensitivity yield (from 93.3% to 98.2%; P < .001) but did not significantly increase the mastectomy rate (from 48.2% to 49.3%; P = .177).MG has limited diagnostic sensitivity in patients with small breast cancer, especially in those with dense breast tissue. US is better than MG at detecting small breast cancer, regardless of breast density. The addition of MRI to MG and US could increase sensitivity without increasing the mastectomy rate. This study suggests performing MRI routinely on the basis of MG and US for small (≤2 cm) breast cancer.

Association Between a Tri-allelic Polymorphism in the Estrogen Metabolism Oxidoreductase NRH:Quinone Oxidoreductase 2 Gene and Risk of Breast Cancer by Molecular Subtype.

Background: We hypothesized that NRH:quinone oxidoreductase 2 (NQO2) is a candidate susceptibility gene for breast cancer because of its known enzymatic activity on estrogen-derived quinones. A tri-allelic polymorphism in the NQO2 gene might be associated with the risk of luminal-like breast cancer. Methods: In this case-control study, 2,865 women were recruited, including 1,164 patients with pathologically confirmed breast cancer and 1,701 cancer-free controls. The tri-allelic genetic polymorphism (I-29, I-16, and D alleles) was genotyped by a polymerase chain reaction and restriction fragment length polymorphism (RFLP)-based assay. Because the I-16 allele frequency is rare (approximately 1.0%), individuals carrying the I-16 allele were excluded from the analysis. Breast cancer subtypes were classified according to ER, PR, HER2, and grade. Results: In the association analysis of allele, an increased risk of breast cancer is associated with I-29 allele [82.5% in case group and 79.0% in the control group; odds ratio (OR), 1.25; 95% CI, 1.09-1.43, compared with D allele, p = 0.0015]. In the association analysis of genotype, the I-29-containing genotype was significantly correlated with breast cancer under a dominant model (adjusted OR, 1.31, 95% CI, 1.12-1.54, p = 0.001). Moreover, in the subtype analysis, there was a significant association of the I-29/D polymorphism with luminal-like breast cancer (adjusted OR, 1.54, 95% CI, 1.22-1.94, p = 0.001 for luminal-A disease; adjusted OR, 1.37, 95% CI, 1.06-1.76, p = 0.014 for luminal-B disease) but not with HER2-enriched or triple-negative subtypes. Conclusion: The tri-allelic polymorphism in the NQO2 gene is associated with breast cancer risk, especially for the luminal-like subtype. Our findings provide a new piece of molecular epidemical evidence supporting the hypothesis that estrogen and its metabolites are carcinogens of luminal-like breast cancer. Further external validation studies are needed.

LncRNA PCAT7 promotes the malignant progression of breast cancer by regulating ErbB/PI3K/Akt pathway.

Aim: This study aimed to explore the mechanism of lncRNA PCAT7 underlying the progression of breast cancer, which will provide a basis for accurate diagnosis and targeted treatment. Methods: Data from The Cancer Genome Atlas data associated with breast cancer were used to identify the target lncRNA. In vitro experiments were conducted to detect gene expression and the effect of the lncRNA on cancer cell activities. Results: PCAT7 was found to be highly expressed in breast cancer tissue and cells, which activated the ErbB/PI3K/Akt pathway to potentiate cancer cell proliferation, migration and invasion and suppress apoptosis. Conclusion: PCAT7 is likely to promote tumor cell activities by activating ErbB/PI3K/Akt pathway, in turn potentiating tumor malignant progression.