EGFR mutation testing in pulmonary adenocarcinoma: evaluation of tumor cell number and tumor percent in paraffin sections of 120 small biopsies

EGFR and HER-2 oncogenes expression in an experimental model of two-stage chemically induced carcinogenesis in mouse skin

The aim of the study was to investigate the expression of EGFR and HER-2 oncogenes using an experimental two stage chemically induced carcinogenesis protocol on the dorsal skin in FVB/N mice. Forty female FVB/N mice 4 weeks old, were grouped into one control (n = 8) and two experimental groups (Group A: n = 16, Group B: n = 16) following a randomization process. Two-stage carcinogenesis protocol, was implicated, including an initial treatment with 97.4 nmol DMBA on their shaved dorsal skin and subsequent treatments of 32.4 nmol TPA applications after 13 weeks for Group A and after 20 weeks for Group B. The control group C, received no treatment. Skin was examined weekly for tumor development. Post-experiment, animals were euthanized for tissue analysis. The histological status of the skin lesions in the experimental groups corresponded well with tumour advancement (from dysplasia to poorly-differentiated carcinoma). Tumour sections were evaluated histologically and immunohistochemically. EGFR expression was found significantly higher in precancerous and malignant tumours (p = 042 and p = 008 respectively), while tended to be higher in benign tumours (p = 079), compared to normal histology. Moreover, mean percentage of EGFR positive expression in malignant tumours was significantly higher than in benign tumours (p < 001). HER-2 expression was found significantly higher in precancerous and malignant tumours (p = 042 and p = 015 respectively), while tended to be higher in benign tumours (p = 085), compared to normal histology. Furthermore, mean percentage of HER-2 positive expression in malignant tumours was significantly higher than in benign tumours (p = 005). The study demonstrated that in FVB/N mice subjected to a two-stage chemically induced carcinogenesis protocol, there was a significant increase in the expression of EGFR and HER-2 oncogenes in precancerous and malignant skin lesions compared to normal tissue. This suggests a potentially early role of these oncogenes in the progression of skin tumours in this model.

Enhanced ultrasound-guided versus non-enhanced ultrasound-guided percutaneous needle biopsy in tissue cellularity of lung malignancies: a propensity score matched study

BACKGROUND

Though ultrasound-guided percutaneous lung needle biopsy (US-PLNB) is a first-line small biopsy method for peripheral lung lesions, quality of cellularity in specimens obtained via US-PLNB is uncertain. This study investigated the accuracy, sensitivity, and cellularity of US-PLNB. It examined the ability of contrast-enhanced ultrasound (CEUS) to improve the effectiveness of US-PLNB.

METHODS

We retrospectively analyzed all data of patients with subpleural lung lesions who underwent US-PLNB. The cellularity of US-PLNB from malignant lesions included the tumor cell number and proportion. The definition of high-quality cellularity (HQC) was concurrently achieving a tumor cell number ≥400 and a proportion ≥20%. The sensitivity, the actual numbers of tumor cell number/proportion, and the rate of HQC were calculated and compared between the CEUS and non-enhanced US groups after propensity score matching (PSM) with subgroup analyses by lesion size (small lesion ≤30 mm and large lesion >30 mm).

RESULTS

A total of 345 patients undergoing 345 US-PLNBs were evaluated, with 3.7±1.1 of punctures on average. There were 201 malignant and 144 benign lesions with a mean size of 43.8±24.1 mm. Among the 201 malignant lesions, 124 cases underwent CEUS and 77 underwent non-enhanced US. The quantity of tumor cells, the proportion of tumor cells, and the rate of HQC in 201 cases of US-PLNB from malignant lesions were 2,862.1±2,288.0, 44.6%±24.5%, and 82.1% [95% confidence interval (CI): 76.6% to 87.1%], respectively. The quantity of tumor cells, the proportion of tumor cells, and rate of HQC were significantly higher in the CEUS group than that in the non-enhanced US group, both in the analysis of overall malignant lesions and in large malignant lesions (all P<0.05).

CONCLUSIONS

The US-PLNB has high sensitivity and thereby obtains HQC samples for subpleural lung malignant lesions. The CEUS helps improve the rate of HQC and tissue cellularity of lung malignancies.

TRAF6 regulates EGF-induced cell transformation and cSCC malignant phenotype through CD147/EGFR

TRAF6, a well-known adapter molecule, plays pivotal role in TLR/IL-1R associated signaling pathway. Although TRAF6 has been shown to have oncogenic activity in various malignant tumors, the details remain unclear. In this study, we demonstrated that TRAF6 facilitates Ras (G12V) and EGF-induced cellular transformation through EGFR. Silencing of TRAF6 expression significantly downregulated AP-1 activity, as well as MMP-2,9 expression after EGF stimulation. Furthermore, we found that TRAF6 plays an essential role in cutaneous squamous cell carcinoma (cSCC) malignant phenotypes, affecting cell growth and migration. CD147/Basigin, a transmembrane glycoprotein belonging to the immunoglobulin superfamily, is over-expressed in tumors and induces tumorigenesis. Our results showed that CD147 formed complex with EGFR and TRAF6. Knockdown of TRAF6 disrupted the CD147-EGFR complex, thereby inducing EGFR endocytosis. Therefore, TRAF6 might be a novel molecular target for cSCC prevention or therapy.

EGFR, KRAS, BRAF and HER2 testing in metastatic lung adenocarcinoma: Value of testing on samples with poor specimen adequacy and analysis of discrepancies

Molecular testing on metastatic lung adenocarcinoma or on non-small cell non-squamous lung carcinoma often relies on small specimen. In this group of patient with poor specimen adequacy, we analyzed the rate of EGFR, KRAS, BRAF and HER2 mutations compared to their rate in optimal specimen. We analyzed discrepancies in molecular testing results in patients with iterative analysis on several samples. We performed a retrospective study of 1538 samples consecutively analyzed. 263/665 (39,5%) biopsies and 37/708 (5,2%) surgical specimens were considered as samples with poor specimen adequacy (p<0,0001). A lower tumor cell content was associated with a lower rate of KRAS mutation: 15,8% in samples with <10% of tumor cells or <100 tumor cells versus 29,8% in samples with >10% tumor cell and >100 tumor cells (p=0,001). KRAS mutational rate was at 11,1% in cytology specimens, significantly lower than in biopsy or surgical specimens respectively at 28,2% and 28,5% (p=0,0002). Tumor cell content was not associated with mutational rate for EGFR, BRAF and HER2 mutations. DNA quantity was not associated with mutational rate for EGFR, KRAS, BRAF and HER2. A discrepancy in molecular testing was found in 16 patients. For 5 patients there was also a discrepancy for TTF-1 expression. On the 11 without TTF-1 discrepancy, specimen adequacy was not fulfilled in 10 cases at least for tumor content. Discrepancies were found in the case of low cellularity, poor cell content or testing on cytological specimens. Tumor cell content is a crucial parameter for molecular analysis rather than the type of specimen or the DNA quantity. Discrepancies in molecular testing results are rare but might suggest the presence of another tumor type, the emergence of another clone or a molecular testing in a sample with low cell content.

Optimized immunohistochemistry using the D5F3 antibody provides a reliable test for identification of ALK-positive lung adenocarcinomas

We used optimized immunohistochemistry (IHC) with the D5F3 antibody for detection of tumours in a prospective study of 307 pulmonary adenocarcinomas. Cases positive by IHC (1+, 2+, 3+) were further investigated by fluorescent in situ hybridization (FISH). Of 307 cases, 22 (7.2%) were moderately intensely positive (2+/3+); 18 of these (82%) were also positive by FISH. Of the four IHC-positive/FISH-negative cases, one was unsuitable for FISH and three had abnormalities of the ALK gene. All cases with weak reactivity with D5F3 (1+) were FISH-negative. The FISH positive/IHC-positive cases with moderately intense reactivity had the typical clinicopathologic features of ALK-positive patients (younger age, p < 0.01; higher frequency in metastatic sites, p < 0.01; cribriform/mucinous/signet histology, p < 0.01; stage IV disease, p < 0.01). In conclusion, our findings indicate that optimized IHC using the D5F3 antibody provides a reliable and inexpensive test for identification of ALK-positive adenocarcinomas. Inclusion of this information in the pathology report at the time of the histological diagnosis might significantly shorten time to treatment.

Impact of Cytological Sampling on EGFR Mutation Testing in Stage III-IV Lung Adenocarcinoma

Objectives. There have been advances in the identification and understanding of molecular subsets of lung cancer, defined by specific oncogenic aberrations. A number of actionable genetic alterations have been identified, such as the epidermal growth factor receptor (EGFR) mutation. We aimed to establish the reasons why patients were not undergoing EGFR mutation testing at the time of histological diagnosis. Methods. The records of 70 patients with advanced adenocarcinoma of the lung managed through a single multidisciplinary team at a single institution were reviewed. Data were collected on method of tumour sample collection, whether this was sent for EGFR testing, and the result. Results. Seventy patients were identified. In 21/25 (84%) cases, cytological sampling was sufficient for EGFR mutation analysis, compared with 40/45 (89%) cases with histological sampling. EGFR mutation testing was not carried out in 22/70 (31.4%) patients. There was insufficient tumour sample for EGFR testing in 9/22 (40.9%) patients. Other reasons for not testing included poor patient fitness and problems in the diagnostic pathway. Conclusions. In this series, cytological tumour sampling was not the predominant reason why cancers failed to have EGFR mutation status established.

Sample types applied for molecular diagnosis of therapeutic management of advanced non-small cell lung cancer in the precision medicine

In this era of precision medicine, molecular biology is becoming increasingly significant for the diagnosis and therapeutic management of non-small cell lung cancer. The specimen as the primary element of the whole testing flow is particularly important for maintaining the accuracy of gene alteration testing. Presently, the main sample types applied in routine diagnosis are tissue and cytology biopsies. Liquid biopsies are considered as the most promising alternatives when tissue and cytology samples are not available. Each sample type possesses its own strengths and weaknesses, pertaining to the disparity of sampling, preparation and preservation procedures, the heterogeneity of inter- or intratumors, the tumor cellularity (percentage and number of tumor cells) of specimens, etc., and none of them can individually be a “one size to fit all”. Therefore, in this review, we summarized the strengths and weaknesses of different sample types that are widely used in clinical practice, offered solutions to reduce the negative impact of the samples and proposed an optimized strategy for choice of samples during the entire diagnostic course. We hope to provide valuable information to laboratories for choosing optimal clinical specimens to achieve comprehensive functional genomic landscapes and formulate individually tailored treatment plans for NSCLC patients that are in advanced stages.

Evaluation of a novel saliva-based epidermal growth factor receptor mutation detection for lung cancer: A pilot study

BACKGROUND

This article describes a pilot study evaluating a novel liquid biopsy system for non-small cell lung cancer (NSCLC) patients. The electric field-induced release and measurement (EFIRM) method utilizes an electrochemical biosensor for detecting oncogenic mutations in biofluids.

METHODS

Saliva and plasma of 17 patients were collected from three cancer centers prior to and after surgical resection. The EFIRM method was then applied to the collected samples to assay for exon 19 deletion and p.L858 mutations. EFIRM results were compared with cobas results of exon 19 deletion and p.L858 mutation detection in cancer tissues.

RESULTS

The EFIRM method was found to detect exon 19 deletion with an area under the curve (AUC) of 1.0 in both saliva and plasma samples in lung cancer patients. For L858R mutation detection, the AUC of saliva was 1.0, while the AUC of plasma was 0.98. Strong correlations were also found between presurgery and post-surgery samples for both saliva (0.86 for exon 19 and 0.98 for L858R) and plasma (0.73 for exon 19 and 0.94 for L858R).

CONCLUSION

Our study demonstrates the feasibility of utilizing EFIRM to rapidly, non-invasively, and conveniently detect epidermal growth factor receptor mutations in the saliva of patients with NSCLC, with results corresponding perfectly with the results of cobas tissue genotyping.