Mutation analysis of mucosal and cutaneous melanomas during progression.

2017 ◽  
Vol 35 (15_suppl) ◽  
pp. e21047-e21047
Author(s):  
Giuseppe Palmieri ◽  
Maria Colombino ◽  
Milena Casula ◽  
Amelia Lissia ◽  
Gerardo Botti ◽  
...  

e21047 Background: The prevalence of mutations in driver genes during progression in cutaneous and mucosal melanomas remains inconclusive. We investigated the prevalence and distribution of mutations in main candidate genes involved in melanomagenesis among different melanoma tissues using a next-generation sequencing (NGS) approach. Methods: Forty-eight tumor samples from 36 patients with mucosal melanoma (MM) and fifty-two tumor samples from 34 patients with cutaneous melanoma (CM) were collected, after obtaining patients’ written informed consent for tissue sampling. Genomic DNA was isolated from macrodissected tumor tissues containing at least 80% neoplastic cells and analyzed for mutations in 25 most common melanoma-associated oncogenes and tumor suppressor genes, using the IMI Diagnostic Melanoma Panel on the Ion Torrent platform (Life Technologies, USA). Results: A total of 100 tumor tissues from 70 melanoma patients were analyzed. BRAF mutations were detected in 21/34 (62%) CM patients and 13/36 (36%) mm patients. The second most prevalent mutations were found in K-/N-RAS (6/34; 18%) and cKIT (6/36; 17%) genes among CM and mm patients, respectively. No concomitant mutations of BRAF, RAS, and cKIT genes were detected. Among others, mutations were more frequently found in CCND1 (20%), ARID2 (16%), and NF1(12%) genes, considering the entire series of patients. Vast majority of patients who had paired samples of primary and secondary melanomas showed consistent mutation patterns between primary tumors and metastatic lesions. Similar frequencies of mutations in driver genes were seen across metastatic sites. Conclusions: In the era of targeted therapies, assessment of the spectrum and distribution of mutations in main molecular targets among patients with melanoma is needed. Our findings about the prevalence of mutations in driver genes in paired tumor lesions from patients with cutaneous and mucosal melanoma may be useful in the management of such diseases. The Italian Melanoma Intergroup (IMI) includes the following additional members who participated as investigators in this study: Mario Mandalà, Paola Queirolo, Ignazio Stanganelli, Vanna Chiarion Sileni, Pietro Quaglino, Anna Maria Di Giacomo.

2012 ◽  
Vol 30 (20) ◽  
pp. 2522-2529 ◽  
Author(s):  
Maria Colombino ◽  
Mariaelena Capone ◽  
Amelia Lissia ◽  
Antonio Cossu ◽  
Corrado Rubino ◽  
...  

Purpose The prevalence of BRAF, NRAS, and p16CDKN2A mutations during melanoma progression remains inconclusive. We investigated the prevalence and distribution of mutations in these genes in different melanoma tissues. Patients and Methods In all, 291 tumor tissues from 132 patients with melanoma were screened. Paired samples of primary melanomas (n = 102) and synchronous or asynchronous metastases from the same patients (n = 165) were included. Tissue samples underwent mutation analysis (automated DNA sequencing). Secondary lesions included lymph nodes (n = 84), and skin (n = 36), visceral (n = 25), and brain (n = 44) sites. Results BRAF/NRAS mutations were identified in 58% of primary melanomas (43% BRAF; 15% NRAS); 62% in lymph nodes, 61% subcutaneous, 56% visceral, and 70% in brain sites. Mutations were observed in 63% of metastases (48% BRAF; 15% NRAS), a nonsignificant increase in mutation frequency after progression from primary melanoma. Of the paired samples, lymph nodes (93% consistency) and visceral metastases (96% consistency) presented a highly similar distribution of BRAF/NRAS mutations versus primary melanomas, with a significantly less consistent pattern in brain (80%) and skin metastases (75%). This suggests that independent subclones are generated in some patients. p16CDKN2A mutations were identified in 7% and 14% of primary melanomas and metastases, with a low consistency (31%) between secondary and primary tumor samples. Conclusion In the era of targeted therapies, assessment of the spectrum and distribution of alterations in molecular targets among patients with melanoma is needed. Our findings about the prevalence of BRAF/NRAS/p16CDKN2A mutations in paired tumor lesions from patients with melanoma may be useful in the management of this disease.


2018 ◽  
Vol 50 (4) ◽  
pp. 1378-1387 ◽  
Author(s):  
Si-Hyung Lee ◽  
Jee Eun Kim ◽  
Hong Sun Jang ◽  
Kyu Hyun Park ◽  
Byung Ho Oh ◽  
...  

2020 ◽  
Vol 12 (1) ◽  
Author(s):  
Wei Lin ◽  
Pawan Noel ◽  
Erkut H. Borazanci ◽  
Jeeyun Lee ◽  
Albert Amini ◽  
...  

Abstract Background Solid tumors such as pancreatic ductal adenocarcinoma (PDAC) comprise not just tumor cells but also a microenvironment with which the tumor cells constantly interact. Detailed characterization of the cellular composition of the tumor microenvironment is critical to the understanding of the disease and treatment of the patient. Single-cell transcriptomics has been used to study the cellular composition of different solid tumor types including PDAC. However, almost all of those studies used primary tumor tissues. Methods In this study, we employed a single-cell RNA sequencing technology to profile the transcriptomes of individual cells from dissociated primary tumors or metastatic biopsies obtained from patients with PDAC. Unsupervised clustering analysis as well as a new supervised classification algorithm, SuperCT, was used to identify the different cell types within the tumor tissues. The expression signatures of the different cell types were then compared between primary tumors and metastatic biopsies. The expressions of the cell type-specific signature genes were also correlated with patient survival using public datasets. Results Our single-cell RNA sequencing analysis revealed distinct cell types in primary and metastatic PDAC tissues including tumor cells, endothelial cells, cancer-associated fibroblasts (CAFs), and immune cells. The cancer cells showed high inter-patient heterogeneity, whereas the stromal cells were more homogenous across patients. Immune infiltration varies significantly from patient to patient with majority of the immune cells being macrophages and exhausted lymphocytes. We found that the tumor cellular composition was an important factor in defining the PDAC subtypes. Furthermore, the expression levels of cell type-specific markers for EMT+ cancer cells, activated CAFs, and endothelial cells significantly associated with patient survival. Conclusions Taken together, our work identifies significant heterogeneity in cellular compositions of PDAC tumors and between primary tumors and metastatic lesions. Furthermore, the cellular composition was an important factor in defining PDAC subtypes and significantly correlated with patient outcome. These findings provide valuable insights on the PDAC microenvironment and could potentially inform the management of PDAC patients.


2018 ◽  
Vol 36 (4_suppl) ◽  
pp. 623-623
Author(s):  
Afsaneh Barzi ◽  
Mohamed E. Salem ◽  
Joanne Xiu ◽  
Wolfgang Michael Korn ◽  
John Marshall ◽  
...  

623 Background: Females (F) have a lower incidence of CRC and carry a better overall prognosis than males(M). We explored the differences in the molecular profile of CRC as an explanation for the differences in the outcome. Methods: CRC cases submitted to Caris Life Sciences from 2015 to 2017 were analyzed. These cases were tested with next generation sequencing (NGS) of 592 genes and a panel of IHC and copy number variation assessment. Microsatellite instability (MSI) was evaluated with NGS for known MSI loci in the target regions. High Tumor mutational load (TML-H) was defined as ≥17 mutations/megabase. Results: Data from a total of 1768 CRC tumors (F: 859; M: 909) was available for analysis. The mean age at testing was similar between the two groups (F 59 vs. M 60 years). Tumor location was unknown in more than 40% of the cases. For those with known tumor location (1056) F had a higher rate in right sided than left sided and rectal tumors (51% vs. 47% vs. 40%, p = 0.006). Overall, F carried significantly lower frequency of mutation in APC (68% vs. 74%, p = 0.02), higher frequency of BRAF (11% vs. 6.6%, p = 0.003) and BRCA1 (2% vs. 0.6%, p = 0.007). PDL1 expression was higher in F (4.5% vs. 2.1%, p = 0.006) and MGMT expression was higher in M (63% vs. 56%, p = 0.04). There was no significant difference in the TML-H (F:6.4% vs. M:5.9%) and MSI-high (F:6.2% in vs M:4.8%). When primary (877) and metastatic tumors (838) were investigated separately, mutations in APC was higher in M primary tumors (74% vs. 68% p = 0.03) while not different in metastatic sites. On the contrary, BRCA1 mutations were higher in the metastatic sites for F (2% vs. 0.2%, p = 0.02). PD-L1 was higher in the primary tumor of F (5.2% vs. 1.8%, p = 0.008) and PD-1 on tumor infiltrating lymphocyte in metastatic tumors in F (48% vs. 30%, p = 0.01). Conclusions: The profile of female patients (higher rates of PDL1 in primary and PD1 in metastatic tumors) supports a higher degree of immune evasion. The differences in the profile of metastatic vs. primary sites may be due to the differences in the mechanism of metastasis in females vs. males and may have implications for PDX models.


2018 ◽  
Vol 36 (5_suppl) ◽  
pp. 105-105
Author(s):  
Yuji Miura ◽  
Takanobu Motoshima ◽  
Nanako Wakigami ◽  
Natsuki Kusada ◽  
Toshikazu Okaneya ◽  
...  

105 Background: Tumor-associated macrophages (TAMs) are one of the key contributors to the tumor microenvironment and are phenotypically differentiated into M1 and M2 macrophages. M1 macrophages stimulate anti-tumor immune responses, whereas M2 macrophages promote immunosuppression and are associated with tumor progression in clear cell renal cell carcinoma (ccRCC). However, little information is available regarding the difference in TAM polarization between primary and metastatic lesions of ccRCC. Methods: We collected paired samples of primary and matched metastatic sites from the first recurrence in 41 metastatic ccRCC patients. Immunohistochemistry (IHC) for Iba1, which is a common pan-macrophage marker, and CD163 and CD204, which are considered to be M2 macrophage markers, was performed on all paired samples. Results: Thirty-three paired primary and metastatic samples were available for IHC assessment in this analysis. The most common metastatic sites were lung (N = 26, 78.8 %) and lymph node (N = 3, 9.1 %). The mean (± standard deviation) cell density of Iba1+ TAMs was higher in metastatic lesions than in primary lesions (756 ± 267 mm2 vs. 581 ± 155 mm2, P = 0.0012). By contrast, the ratio of CD163+ and CD204+ to Iba1+ TAMs was significantly lower in metastatic lesions than in primary lesions (0.76 ± 0.30 vs. 0.90 ± 0.24, P = 0.0067 and 0.39 ± 0.27 vs. 0.67 ± 0.29, P = 0.0001, respectively). The median overall survival of patients with high- vs. low-density Iba1+, CD163+, and CD204+ TAMs in metastatic lesions was 120 vs. 92 months (log-rank P = 0.67), 120 vs. 58 months (log-rank P = 0.056), and 120 vs. 92 months (log-rank P = 0.35), respectively. Conclusions: TAMs in the metastatic lesions of ccRCC polarized towards an M1-like phenotype, although the total number of TAMs was greater in metastatic compared with primary lesions. The cell density of Iba1+, CD163+, and CD204+ TAMs in metastatic sites was not associated with overall survival in patients with ccRCC.


2019 ◽  
Vol 20 (24) ◽  
pp. 6191 ◽  
Author(s):  
Takamichi Ito ◽  
Yumiko Kaku-Ito ◽  
Maho Murata ◽  
Toshio Ichiki ◽  
Yuki Kuma ◽  
...  

The current development of BRAF inhibitors has revolutionized the treatment of unresectable melanoma. As the potential heterogeneity of BRAF mutations in melanoma has been reported, accurate detection of BRAF mutations are important. However, the genetic heterogeneity of acral melanoma—a distinct type of melanoma with a unique genetic background—has not fully been investigated. We conducted a retrospective review of our acral melanoma patients. Of the 196 patients with acral melanoma, we retrieved 31 pairs of primary and matched metastatic melanomas. We immunostained the 31 pairs with VE1, a BRAFV600E-mutation-specific monoclonal antibody. Immunohistochemistry with VE1 showed a high degree of sensitivity and specificity for detecting BRAFV600E mutations compared with the real-time polymerase chain reaction method. A total of nine primary (29.0%) and eight metastatic (25.8%) acral melanomas were positive for VE1. In three patients (9.7%), we observed a discordance of VE1 staining between the primary and metastatic lesions. Of note, VE1 immunohistochemical staining revealed a remarkable degree of intra-tumor genetic heterogeneity in acral melanoma. Our study reveals that VE1 immunostaining is a useful ancillary method for detecting BRAFV600E mutations in acral melanoma and allows for a clear visualization of intra- and inter-tumor BRAF heterogeneity.


2021 ◽  
Vol 9 (4) ◽  
pp. e002230
Author(s):  
Myrto K Moutafi ◽  
Weiwei Tao ◽  
Richard Huang ◽  
James Haberberger ◽  
Brian Alexander ◽  
...  

Assessment of programmed cell death-ligand 1 (PD-L1) expression by immunohistochemistry (IHC) is the definite diagnostic test to guide treatment for patients with advanced-stage non-small cell lung cancer. Intratumoral heterogeneity and discrepancy of PD-L1 expression between primary and metastatic lesions may increase the risk of tumor misclassification. We performed a retrospective study of the Foundation Medicine, Inc clinical database on lung cancer cases that were evaluated for PD-L1 expression by IHC in the context of routine care. All cases were assessed with the Food and Drug Administration-approved 22C3 pharmDx assay and scoring system. 15,028 lung cancer cases, including 8285 primary tumors and 6743 unmatched metastatic lesions were analyzed. Metastatic lesions (mets) were more frequently high positive (tumor proportion score (TPS) ≥50%) for PD-L1 expression than primary lesions (33.8% vs 28.4%; OR, 1.28; 95% CI, 1.19 to 1.37; p<0.001). Higher levels in mets than primaries were seen in samples from lymph nodes, pleural fluid, soft tissue and adrenal gland but not in those from liver, brain and bone. Metastatic lesions of patients with non-squamous histology were more likely to have TPS ≥50% in comparison with primary (OR, 1.37; 95% CI, 1.27 to 1.49; p<0.001), but this was not the case for patients with squamous histology (OR, 0.89; 95% CI, 0.74 to 1.06; p=0.197). PD-L1 expression varies with respect to histologic subtype, sampling site and gender, but is generally higher in metastatic sites. This observation may affect future patient management and trial design.


2017 ◽  
Vol 35 (15_suppl) ◽  
pp. 4569-4569 ◽  
Author(s):  
Lisa Derosa ◽  
Gwenael Le Teuff ◽  
Manal Khordahi ◽  
Brice Chanez ◽  
Emanuelle Zalcman ◽  
...  

4569 Background: Although inhibition of PD-1/PD-L1 and MET receptors have clinical efficacy in mRCC, their expression is not a predictive biomarker. Heterogeneity between the sites of disease might be one explanation. The aim of our study was to evaluate PD-L1 and MET expression in primary and metastases (brain (BM)/pancreas (PM)) RCC lesions and their correlation with clinicopathologic characteristics. Methods: RCC specimen from different institutions were collected. Clinicopathologic characteristics were assessed by revision of samples. PD-L1 and MET expression in tumor cells (TC) and immune cells (IC) ( > 1%) were assessed by immunohistochemistry. Results: 180resected RCC specimen were successful collected (42 primary tumors and 138 metastases (87 BM/51 PM)). Overall, 22%, 51% and 23% of patients had at least one specimen expressing PD-L1 TC, IC and MET, respectively. In primary tumours, the proportion was 12%, 50% and 0%, respectively. In metastasis, the proportion of PD-L1 TC was 22% (23% in BM vs 19% in PM, p = 0.631), PD-L1 IC was 48% (47% in BM vs 49% in PM, p = 0.821) and MET was 24% (35% in BM vs 2% in PM, p < 0.001). Comparing paired samples (primary tumour and metastasis) there was discordances of PD-L1 in TC or IC and of MET expression in 30%, 27% and 24% of samples, respectively. These two first disagreements seem varied over time. The discordance in PD-L1 TC or IC and MET between primary tumor and PM (BM) was 15% (40%), 33% (22%) and 0% (67%), respectively. Some correlations were observed between MET and PD-L1 and clinicopathologic characteristics. Conclusions: In this largest analysis, evaluating heterogeneity between primary tumor and metastases (brain/pancreatic lesions) in mRCC, PD-L1 and MET expression suggests that the assessment as predictive biomarkers may require analysis of metastatic lesions. [Table: see text]


2019 ◽  
Vol 37 (15_suppl) ◽  
pp. e15083-e15083
Author(s):  
Beili Wang ◽  
Fei Huang ◽  
Minna Shen ◽  
Shengchao Wu ◽  
Qian Yu ◽  
...  

e15083 Background: Clonal hematopoiesis (CH) leads to blood-derived somatic mutations in KRAS, NRAS and BRAF. Our aim is to identify the prevalence of CH-derived mutations in these three genes in metastatic colorectal cancer (mCRC) patients and reveal the practical clinical implication of these mutations on plasma genotyping. Methods: We analyzed KRAS, NRAS and BRAF genotypes in plasma and matched tumor tissues of 236 mCRC patients through next-generation sequencing (NGS) and polymerase chain reaction. Suspected CH mutations were defined as those only detected in plasma with variant allelic frequencies (AFs) of <5% and were confirmed by paired peripheral blood cells (PBCs) using droplet digital PCR (ddPCR). The hemopoietic lineage harboring a CH-derived mutation was analyzed through flow cytometry. Results: We identified suspected CH mutations in twenty patients (8.4%, 20/236). Three of these patients (1.27%, 3/236) had a CH-derived KRAS mutation, which was confirmed present in paired PBCs. Two of them had a KRAS G12X and the third had a KRAS Q61H. We did not detect CH-derived NRAS or BRAF mutations in our cohort. All three patients harboring a CH-derived mutation previously received chemotherapy treatment. In a selected CH-derived KRAS G12X case, the mutation was enriched in lymphocytes and persisted in plasma cell-free DNA (cfDNA) over the course of 4 months of therapy. Conclusions: In summary, we confirmed the existence of CH-derived KRAS mutations in a small proportion of mCRC patients. This should be noted to prevent misclassification as tumor somatic mutations when performing cfDNA sequencing in the absence of genotyping matched PBCs.


Sign in / Sign up

Export Citation Format

Share Document