Concordant point mutation of ETS-related gene (ERG) in tumor tissues from a synchronous multiple primary lung cancer: A case report / 北京大学学报(医学版)

The rearrangement of the gene encoding the transcription factor ETS-related gene (ERG) is thought to play a key role in the development of prostate cancer. However, the studies on the ERG mutations have been rarely reported in non-small cell lung carcinoma (NSCLC). Here, we reported genetic features regarding a case of a 68-year-old male patient who presented the primary synchronous multiple tumor lesions in the separated lungs. The patient was hospitalized due to the presence of tumor lesions at the right and left lungs revealed by a chest computerized tomography (CT) scan. After conducting lobectomies at the both lungs, the tumor nodules were all removed, and the histological analysis suggested adenocarcinoma at the both tumor lesions. The patient was diagnosed with synchronous multiple primary lung cancer (SMPLC) based on Martini-Melamed criteria and American College of Chest Physicians practice guidelines. An exome analysis of 315 genes in the two tumor lesions and a non-tumor lesion was conducted by using Illumina Nextseq500 platform from each tumor region to decipher a potential evolutional progress of SMPLC. Single or pair-end reads were first mapped to a human genome reference and filtered based on the mapping quality score. The read depth was ≥ 1 000× and the depth of coverage was 95%. The data revealed a discordant epidermal growth factor receptor (EGFR) from the separate lungs; additionally, a high frequency of point mutation on exon 9 H310P of the ERG gene was detected at the both sites of the tumor lesions. This case showed that a potential role of the molecular features analysis from each tumor lesion might contribute to the understanding of the evolutional development of SMPLC. This study suggests that the same environment may contribute certain gene(s) mutations in the same sites in the early stages of polyclonal tumor origins; meanwhile the extensive studies on these genes may help us understand the evolution and progress of tumor clones.

Immunohistochemical expression of Ets‑related gene‑transcriptional factor in adenocarcinoma prostate and its correlation with Gleason score.

Background: Prostate carcinoma is the second leading cause of cancer‑related deaths in males worldwide. The burden is expected to grow 1.7 million new cases and 499,000 new deaths by 2030. In developing countries such as India, prostate carcinoma will show an increase by 140% in the next few years. Although the diagnosis of prostate carcinoma can usually be made on histological features, now a days many immunohistochemical (IHC) markers are used to distinguish it from benign mimickers as well as in predicting prognosis and treatment. Out of these markers, Ets‑related gene (ERG product) is a proto‑oncogene which participates in chromosomal translocations and is frequently over expressed in prostate carcinoma which harbors ERG‑transmembrane protease, serine 2 fusion. Materials and Methods: Fifty cases of carcinoma prostate diagnosed in needle biopsies and prostatic chips, in the Department of Pathology of a tertiary care teaching hospital in Punjab, India, were included in the present study. The slides were observed under the light microscope, and Gleason scoring was done using the 2005 International Society of Urological Pathology modified Gleason system. IHC study for ERG expression was done on all the cases, for which anti‑ERG monoclonal rabbit clone antibody EP111 (Dako, Denmark) was used. Lymphocytes and endothelial cells were taken as in built positive controls for staining. The intensity of ERG positivity was scored as no staining (0), weak staining (+1), moderate staining (+2) and intense staining (+3). The H score was then calculated by multiplying the intensity of the stain with the percentage (0–100) of the cells showing that staining intensity. The H‑score has a range of 0–300. The relationship between IHC expression and clinico‑pathological parameters was compared and analyzed using Chi-square test. P < 0.05 was considered statistically significant. Results: Majority of patients included in the study were in the age group of 61–80 (84% of the total). When ERG expression was studied with age‑specific rates, it was not found to be statistically significant. The most common pattern noted in the present study was 4 + 3, constituting 36% of total, followed by 3 + 4 constituting 32%. Calculating the score, the majority of patients had a Gleason score of 5–8, constituting 76% of total. Out of the total fifty cases of prostate carcinoma, ERG was positive in 29 cases (58%) and negative in 21 cases (42%). Fourteen out of 21 (48%) of the ERG positive cases had an intensity score of 3. When the ERG intensity was correlated with the Gleason score group, it was seen that patients having Gleason score 7–8 showed ERG positivity in 19 out of 38 cases (50%), with 11/19 (57%) cases showing an ERG intensity score of 3. The Gleason score group 9–10 showed ERG positivity in 83% (10/12) cases, 20% (2/10) cases showing intensity score of 3. This correlation was found to be statistically significant. Conclusion: ERG immunostaining was performed in a small Indian cohort of prostate cancer patients, diagnosed in trucut biopsy specimens and prostatic chips. ERG expression was found in 58% patients. An increase in the ERG expression was observed with an increase in Gleason score. The intensity of ERG expression, however, decreased with an increasing Gleason score.