BRAF Wild-type Patients Research Articles

Efficacy of FOLFIRI plus bevacizumab versus FOLFIRI plus cetuximab in RAS-mutant metastatic colorectal cancer: Final update on patients with RAS-mutant metastatic colorectal cancer treated in FIRE-3.

3550 Background: Doublet chemotherapy plus bevacizumab is a well-established standard of care in the first-line treatment of RAS-mutant (RASmut) metastatic colorectal cancer (mCRC). The FIRE-3 trial was the first randomized study to compare FOLFIRI plus cetuximab to FOLFIRI plus bevacizumab in mCRC. Since this trial initially included patients irrespective of RAS mutation status, the present analysis performs an updated evaluation of therapeutic efficacy of targeted therapy with bevacizumab versus cetuximab in RASmut mCRC. Methods: FIRE-3 trial included 752 patients. Initially, pyrosequencing (PSeq) was used to identify RAS mutations. In a subsequent investigation next-generation sequencing (NGS) was applied in 373 available tumors. A 5% mutant allele cutoff was used for both PSeq and NGS both of which were done centrally. Results: Of the 224 RASmut and BRAF wild-type patients, 187 were identified by polymerase chain reaction (PCR) and PSeq, 122 by NGS. 86 tumors were PCR positive and NGS positive (PCR+/NGS+), 36 tumors PCR negative and NGS positive (PCR-/NGS+). In the overall RASmut cohort of 224 patients, no overall survival (OS) benefit was observed when cetuximab was compared to bevacizumab (20.3 months vs 21.1 months; HR 1.028; 95% CI, 0.547-1.583; P=.842). This effect was observed independent of sidedness of primary tumors (PT) for left-sided (21.5 months vs 22.1 months; HR 1.054; 95% CI, 0.763-1.456) and right-sided PT (19.2 months vs 19.5 months; HR 0.931; 95% CI, 0.547-1.583). Conclusions: While cetuximab notably is not effective in RASmut mCRC, this randomized comparison does not provide an indication for superior efficacy of bevacizumab in the first-line treatment of this patient group. Trial identification number: NCT00433927 [clinicaltrials.gov]

Is there a prognostic difference among stage I lung adenocarcinoma patients with different BRAF-mutation status?

The data of the prognostic role of V-Raf murine sarcoma viral oncogene homolog B1 (BRAF) mutations in early-stage lung adenocarcinoma (LUAD) patients is scarce. This study aimed to investigate the proportion, clinicopathological features, and prognostic significance of patients with stage I LUAD carrying BRAF mutations. We collected 431 patients with pathological stage I LUAD from cBioPortal for Cancer Genomics and 1604 LUAD patients tested for BRAF V600E and epidermal growth factor receptor (EGFR) mutations from Shanghai Pulmonary Hospital. Survival curves were drawn by the Kaplan-Meier method and compared by log-rank test. Cox proportional hazard models, propensity-score matching (PSM), and overlap weighting (OW) were performed in this study. The primary endpoint was recurrence-free survival (RFS). The proportion of BRAF mutations was estimated at 5.6% in a Caucasian cohort. BRAF V600E mutations were detected in six (1.4%) patients in Caucasian populations and 16 (1.0%) patients in Chinese populations. Two BRAF V600E-mutant patients were detected to have concurrent EGFR mutations, one for 19-del and one for L858R. For pathological stage I LUAD patients, BRAF mutations were not significantly associated with worse RFS than wild-type BRAF patients (HR = 1.111; p = 0.885). After PSM and OW, similar results were presented (HR = 1.352; p = 0.742 and HR = 1.246; p = 0.764, respectively). BRAF V600E mutation status also lacked predictive significance for RFS (HR, 1.844; p = 0.226; HR = 1.144; p = 0.831 and HR = 1.466; p = 0.450, respectively). In this study, we demonstrated that BRAF status may not be capable of predicting prognosis in stage I LUAD patients. There is a need for more data to validate our findings.

Incidence and genomic characteristics of gene fusions in a large Chinese colorectal cancer cohort.

192 Background: Gene fusion is rare in colorectal cancer (CRC). With the advent of fusion-targeted therapeutics, such as entrectinib for NTRK fusion and selpercatinib for RET fusion, the identification of gene fusions holds clinical significance. Reports providing a comprehensive description of fusions in CRC are limited, and understanding the molecular characteristics of CRC with fusions will contribute to efficient fusion screening. Here, we investigate the incidence and genomic features of gene fusions in a large Chinese CRC population. Methods: We systematically analyzed next-generation sequencing results of tumor tissue from 5534 CRC patients between January 2020 and August 2023. The sequencing panel covers 769 cancer-related genes and can detect fusions, single nucleotide variants and indels, and microsatellite instability (MSI). Statistical significance was determined using chi-square test. Results: Overall, the median age of patients was 62 years (inter-quartile range [IQR]: 53-70), and 40% were female. Gene fusions were detected in 4.4% (242/5534) of all the patients. The incidence is 0.98% (54/5534) if only reported clinically actionable fusions are considered. The median age of the 242 fusion-positive patients was 64 years (IQR: 54-70), and 43% were female. The most highly detected potentially actionable gene fusions were NTRK (0.89%) and FGFR (0.81%), accounting for 39% of the fusion-positive patients. The other fusion genes were ERBB2 (0.52%), RET (0.38%), BRAF (0.31%), EGFR (0.27%), ALK (0.22%), MET (0.09%) and ROS1 (0.07%). Consistent with previous reports, patients with MSI-High were more likely to have fusions compared with those with microsatellite stability (MSS) or MSI-Low (9.9% vs 4.0%, p < 0.001). Besides, RAS or BRAF mutated patients accounted for 59% of the cohort, of whom 2.5% (83/3273) had fusions detected, while 7.0% (159/2261) of the RAS and BRAF wildtype patients had positive fusions ( p < 0.001). Moreover, 404 (7.3%) patients had RNF43 splice or truncating mutations, and gene fusions were detected in 12.9% of these patients. Combining these markers increased the detection rate of fusions, with 28% (33/118) of the RAS/ BRAF wildtype and MSI-H patients having fusions detected. Furthermore, in patients with wildtype RAS/BRAF and MSI-H and RNF43 splice or truncating mutations, the fusion detection rate was as high as 49% (32/65), including 24 patients with actionable fusions of definite clinical significance. Conclusions: Gene fusions were detected in 4.4% of the Chinese CRC population and tended to occur in patients with wildtype RAS/BRAF, MSI-H, or RNF43 mutations. Combining the mutational status of RAS, BRAF, and RNF43 along with MSI status can improve the fusion detection rate and help select candidates for fusion testing and targeted therapy.

Triplet chemotherapy plus cetuximab as first-line treatment in extended RAS wild-type metastatic colorectal cancer patients

BackgroundTriplet chemotherapy plus cetuximab showed promising results in phase II trials in unsystematically selected RAS population. We evaluated FOLFIRINOX+cetuximab efficacy as first-line treatment in extended RAS wild-type metastatic colorectal cancer (mCRC) patients. MethodsWe retrospectively analyzed patients treated with FOLFIRINOX+cetuximab, using data from clinical trials and real-life practice. Extended mutation analysis was performed when RAS/BRAF status was unavailable. The primary endpoint was progression-free survival (PFS). ResultsSeventy patients (61.4 % male, median age 58.7 years) were analyzed. Eighty percent had left-sided mCRC and 97.1 % had liver metastases. Median PFS and overall survival (OS) were 13.3 and 48.5 months, respectively. The objective response rate was 85.7 %, with 20 % complete response. Primary tumor location did not affect OS and PFS. BRAF wild-type patients (n = 65) had longer PFS (13.3 vs. 6.0 months; p = 0.005) and OS (50.1 vs. 21.2 months; p = 0.007) than BRAF mutated patients (n = 5, including four BRAFV600E). Median OS was significantly longer in resected patients (n = 39, 55.1 vs. 30.7 months; p = 0.030). Main toxicities were diarrhea (31.4 %) and neutropenia (21.4 %). ConclusionFOLFIRINOX+cetuximab provides good PFS, high response rate and prolonged disease control in initially unresectable extended RAS wild-type mCRC. This combination is particularly interesting for selected patients with liver-limited disease eligible to secondary resection.

Efficacy, safety and genomic analysis of SCT200, an anti-EGFR monoclonal antibody, in patients with fluorouracil, irinotecan and oxaliplatin refractory RAS and BRAF wild-type metastatic colorectal cancer: a phase Ⅱ study

Limited therapeutic options are available for metastatic colorectal cancer (mCRC) patients after failure of first- and second-line therapies, representing an unmet medical need for novel therapies. This is an open-label, single arm, multicenter, phase Ⅱ study aiming to perform the efficacy, safety and genomic analysis of SCT200, a noval fully humanized IgG1 anti-epidermal growth factor receptor (EGFR) monoclonal antibody, in patients with fluorouracil, irinotecan and oxaliplatin refractory RAS and BRAF wild-type mCRC. SCT200 (6mg/kg) was given weekly for the first six weeks, followed by a higher dose of 8mg/kg every two weeks until disease progression or unacceptable toxicity. Primary endpoint was independent review committee (IRC)-assessed objective response rate (ORR) and secondary endpoints included ORR in patients with left-sided tumor, disease control rate (DCR), duration of response (DoR), time to response (TTR), progression-free survival (PFS), overall survival (OS) and safety. From February 12, 2018 to December 1, 2019, a total of 110 patients aged between 26 and 77 years (median: 55; interquartile range [IQR]: 47-63) with fluorouracil, oxaliplatin, and irinotecan refractory RAS and BRAF wild-type mCRC were enrolled from 22 hospitals in China. As the data cut-off date on May 15, 2020, the IRC-assessed ORR and DCR was 31% (34/110, 95% confidence interval [CI] 22-40%) and 75% (82/110, 95% CI 65-82%), respectively. Thirty one percent (34/110) patients achieved confirmed partial response (PR). The median PFS and median OS were 5.1 months (95% CI 3.4-5.2) and 16.2 months (95% CI 11.1-not available [NA]), respectively. The most common≥grade 3 treatment-related adverse events (TRAEs) were hypomagnesemia (17%, 19/110) and acneiform dermatitis (11%, 12/110). No deaths occurred. Genomic analysis suggested positive association between MYC amplification and patients' response (P=0.0058). RAS/RAF mutation and MET amplification were the most frequently detected resistance mechanisms. Patients with high circulating tumor DNA (ctDNA) at baseline or without ctDNA clearance at the 7th week after the first dose of SCT200 administration before receiving SCT200 had worse PFS and OS. SCT200 exhibited promising clinical efficacy and manageable safety profiles in RAS and BRAF wild-type mCRC patients progressed on fluorouracil, irinotecan and oxaliplatin treatment. The baseline ctDNA and ctDNA clearance status at the 7th week after the first dose of SCT200 administration before receiving SCT200 could be a potential prognostic biomarker for RAS and BRAF wild-type mCRC patients with SCT200 therapy. This study was sponsored by Sinocelltech Ltd., Beijing, China and partly supported by the National Science and Technology Major Project for Key New Drug Development (2019ZX09732001-006, 2017ZX09304015).

Effect and Interactions of BRAF on Lymph Node Metastasis in Papillary Thyroid Carcinoma With Hashimoto Thyroiditis.

The role of B-Raf proto-oncogene (BRAF) in papillary thyroid carcinoma (PTC) with Hashimoto thyroiditis (HT) is unknown. We aimed to explore risk factors affecting lymph node (LN) metastasis and interaction effect of BRAF in PTC patients with HT. We retrospectively collected the data of 994 PTC patients with HT who underwent surgery at the West China Hospital. We analyzed the correlations between preoperative characteristics and LN metastasis in overall, and different BRAFV600E-mutation patients. Logistic regression was applied to analyze the risk factors for LN metastasis. Finally, we performed an interaction effect analysis to identify the interaction effect of BRAF. The overall LN metastasis rate was 52.71% (524/994); the overall BRAF mutation rate was 26.9% (268/994). BRAF mutation rates were significantly different in LN metastasis and nonmetastasis patients (31.7% vs 21.5%; P < .001). In all 994 patients, age, body mass index (BMI), hypertension, tumor maximum diameter, BRAF mutation, tumor location, aspect ratio, calcification, and extrathyroidal invasion were risk factors for LN metastasis (P < .05). In BRAF-mutant patients, smoking, hypertension, maximum diameter, calcification, and multifocality were risk factors for LN metastasis (P < .05). In BRAF wild-type patients, age, BMI, maximum diameter, tumor location, aspect ratio, tumor shape, calcification, and extrathyroidal invasion were risk factors (P < .05). Additionally, we found statistically significant interactions between BRAF and BMI, hypertension, maximum diameter, and calcification (P < .05), suggesting the potential interaction effect of BRAF. BRAF is a risk factor for LN metastasis in PTC with HT. Meanwhile, BRAF can interact with age, BMI, hypertension, and calcification, which together influence LN metastasis.

Epigenetic signature discriminates lymphatic metastasis in BRAF wild-type thyroid carcinoma: methylation role of GRIK2.

Aim: Conservative treatment approaches for thyroid carcinoma (TC) patients with wild-type B-type Raf kinase (BRAF) pose risks of long-term recurrence. The association of DNA methylation with TC metastasis is unclear. Patients & methods: Here we analyzed data from 179 BRAF wild-type TC patients in the The Cancer Genome Atlasdatabase, identifying significant metastasis-associated CpGs. A logistic regression model was developed and validated for discriminating lymphatic metastasis in BRAF wild-type TC. Results: The model showed high accuracy (AUC: 0.924 training set; 0.812 and 0.773 external cohorts). TAGLN, MRPL4, CLDN10 and GRIK2 emerged as diagnostic markers. GRIK2, downregulated due to promoter hypermethylation, acted as a TC suppressor. Conclusion: Our 5-CpG epigenetic signature effectively discriminates lymphatic metastasis in BRAF wild-type TC, highlighting GRIK2's tumor-suppressive role influenced by promoter hypermethylation.

HER2 Status in RAS and BRAF Wild-Type Metastatic Colorectal Cancer: A Portuguese Study.

Colorectal cancer (CRC) is the second-most deadly cancer worldwide. However, there remains a scarcity of precision treatmentsavailable for this type of cancer. Amplification or overexpression of human epidermal growth factor receptor 2 (HER2+) is a well-established therapeutic target in gastric and breast cancer. HER2is positive in approximately 5% of CRC cases and has been implicated in resistance to therapy with anti-epidermal growth factor receptor antibodies. The aim of this study was to evaluate HER2 status in RAS and BRAF wild-type metastatic CRC (mCRC) and its correlation with survival outcomes. A single-center retrospective analysis of RAS and BRAF wild-type mCRC patients undergoing systemic treatment was conducted from July 2014 to September 2020. Tissue HER2 status was determined by immunohistochemistry (IHC) and/or fluorescence in situ hybridization (FISH) and/or chromogenic in situ hybridization (CISH). HER2+ was defined as IHC3 (+) or IHC2 (+) through FISH or CISH (+). Fifty-nine patients were included. The median age of all the included patients was 64 years (33-82). Four patients had HER2+ tumors (7%). Four patients had HER2+ tumors (7%).The majority of HER2+ mCRC cases were males (n=3) and left-sided CRC (n=3). All patients received FOLFIRI plus cetuximab as first-line treatment. At the median follow-up of 24.0 months, patients with HER2-negative mCRC presented with a median overall survival (mOS) of 39.4 months (95% confidence interval (CI) 32.7-46.0) and the four patients with HER2+ mCRC had a mOS of 20.4 months(95% CI; 9.5-31.3; p=0.07). In HER2-negative patients, themedian PFS (mPFS) was 11.3 months (95% CI; 9.2-13.4) vsHER2-positive patients with a mPFS of 10.9 months (95% CI; 1.3-20.4;p=0.47). To our knowledge, this is the first study reporting HER2+ in mCRC patients in a Portuguese population and the HER2+ rate was consistent with previous studies. Our study suggests that HER2+ may potentially be a marker that is able to predict poor prognosis in RAS and BRAF wild-type mCRC.

Investigation of genetic sex-specific molecular profile in well-differentiated thyroid cancer: Is there a difference between females and males?

Although more common in females, thyroid cancer is deemed to be more aggressive in males. The reasons for sex disparities in thyroid cancer are not well understood. We hypothesised that differences in molecular mutations between females and males contribute to this phenomenon. Retrospective multicentre multinational study of thyroid nodules that underwent preoperative molecular profiling between 2015 and 2022. The clinical characteristics and mutational profiles of tumours in female and male patients were compared. Collected data included demographics, cytology results, surgical pathology, and molecular alterations. A total of 738 patients were included of which 571 (77.4%) were females. The extrathyroidal extension was more common in malignancies in males (chi-squared, p = 0.028). The rate of point mutations and gene fusions were similar in both sex groups (p > 0.05 for all mutations). Patients with nodules with BRAFV600E mutations were significantly younger than BRAF wild-type nodule patients (t-test, p = 0.0001). Conversely, patients with TERT promoter mutations were significantly older than patients with wild-type TERT (t-test, p < 0.0001). For patients harbouring both BRAFV600E and TERT mutations, the difference in age at presentation was significantly different in females (t-test, p = 0.009) but not in males (t-test, p = 0.433). Among females, patients with BRAFV600E and TERT mutations were significantly older than their wild-type or single-mutation counterpart (t-test, p = 0.003). The absolute rate of molecular mutations was similar in females and males. We found that extrathyroidal extension was more common in males. Moreover, BRAFV600E and TERT mutations occur at a younger age in males than in females. These two findings are factors that may explain the tendency of more aggressive disease in males.

Immune checkpoint inhibition in patients with NRAS mutated and NRAS wild type melanoma: a multicenter Dermatologic Cooperative Oncology Group study on 637 patients from the prospective skin cancer registry ADOREG

BackgroundMelanomas frequently harbour somatic mutations in BRAF (40%) or NRAS (20%). Impact of NRAS mutations on the therapeutic outcome of immune checkpoint inhibitors (ICI) remains controversial. Potential correlation of the NRAS mutational status and programmed cell death ligand-1 (PD-L1) expression in melanoma is unknown. Patients and methodsAdvanced, non-resectable melanoma patients with known NRAS mutation status treated with first-line ICI between 06/2014 and 05/2020 in the prospective multicenter skin cancer registry ADOREG were included. Overall response rate (ORR), progression-free survival (PFS), and overall survival (OS) according to NRAS status were analysed. A multivariate Cox model was used to analyse factors associated with PFS and OS; survival was analysed using the Kaplan–Meier approach. ResultsAmong 637 BRAF wild-type patients, 310 (49%) had an NRAS mutation with Q61R (41%) and Q61K (32%). NRAS-mutated (NRASmut) melanomas were significantly more often located on the lower extremities and trunk (p = 0.001); nodular melanoma was the most common subtype (p < 0.0001). No significant differences were found for PFS and OS for anti-PD1 monotherapy (2-year PFS 39%, [95% confidence interval (CI), 33–47] in NRASmut patients and 41% [95% CI, 35–48] in NRAS-wild type (NRASwt) patients; 2-year OS was 54% [95% CI, 48–61] in NRASmut patients and 57% [95% CI, 50–64] in NRASwt patients) and anti-PD1 plus anti-CTLA4 therapy between both cohorts (2-year PFS was 54% [95% CI, 44–66] in NRASmut patients and 53% [95% CI, 41–67] in NRASwt patients; 2-year OS was 58% [95% CI, 49–70] in NRASmut patients and 62% [95% CI, 51–75] in NRASwt patients). The ORR to anti-PD1 was 35% for NRASwt patients and 26% for NRASmut patients and 34% compared to 32% for combinational therapy. Data on PD-L1 expression was available in 82 patients (13%). PD-L1 expression (>5%) was not correlated to NRAS mutational status. In multivariate analysis, elevated lactate dehydrogenase, Eastern Cooperative Oncology Group performance status ≥ 1, and brain metastases were significantly associated with a higher risk of death in all patients. ConclusionsThe PFS and OS were not affected by NRAS mutational status in patients treated with anti-PD1-based ICI. Similar ORR was seen in NRASwt and NRASmut patients. Tumour PD-L1 expression did not correlate with NRAS mutational status.

Hashimoto’s Thyroiditis: A Protective Factor against Recurrence in BRAF-Wild Type Differentiated Thyroid Carcinoma

A recent work analyzing the concomitant factors BRAF mutation (risk factor) and Hashimoto's thyroiditis (HT) (protective factor) found that the presence of HT reduced lymph node metastasis in BRAF-mutated papillary thyroid carcinoma. Whether this notion is upheld with respect to disease recurrence and differentiated thyroid carcinoma (DTC), however, is unknown. We aimed to investigate the effect of underlying HT in DTC patients and its influence on recurrence with a specific emphasis in BRAF-mutated tumors. A total of 469 patients were included. Patients were stratified according to BRAF and HT status. Multivariate regression analysis was conducted to determine protective and risk factors of disease recurrence in patients with DTC. HT was associated with less-aggressive carcinomas including more frequent microcarcinomas (HT: 45.0% vs. no-HT: 34.0%, p = 0.02), less lymph node involvement (HT: 16.4% vs. no-HT: 26.1%, p = 0.02), and less disease recurrence (HT: 2.9% vs. no-HT: 11.9%, p = 0.002). BRAF mutation was also significantly associated with higher rates of lymph node involvement (BRAF-mutant: 41.9% vs. BRAF-wild type: 14.6%, p < 0.001) and almost two times the rate of recurrence (BRAF-mutant: 14.9% vs. BRAF-wild type: 6.5%, p = 0.004). Underlying HT was the only protective factor determined, reducing the odds of developing recurrence by 70% (HR: 0.30, 95%CI: 0.11-0.88). In the BRAF-wild type cohort, regression analysis continued to determine HT as a protective factor (p = 0.03). However, in the BRAF-mutant cohort, HT was no longer an independent protective factor (p = 0.20) against recurrence. Sub-group regression analysis, including PTC patients, similarly found HT as a protective factor only in BRAF-wild type patients (p = 0.039) and not BRAF-mutant (p = 0.627). The presence of underlying HT is associated with less aggressive tumors and is an independent protective factor against DTC recurrence, reducing the risk by 70%. HT remains a protective factor in BRAF-wild type carcinoma, but not in patients with BRAF-mutant carcinoma. HT may potentially be considered as a parameter which enhances American Thyroid Association patient risk stratification.

Brain metastasis and survival outcomes after first-line therapy in metastatic melanoma: a multicenter DeCOG study on 1704 patients from the prospective skin cancer registry ADOREG

BackgroundDespite the availability of effective systemic therapies, a significant number of advanced melanoma patients develops brain metastases. This study investigated differences in incidence and time to diagnosis of brain metastasis...

The profile and prognostic value of circulating lymphocyte subsets in metastatic colon cancer.

Colon cancer (CC) are the most common malignant cancer in human digestive system, however, the profile and prognostic value of circulating lymphocyte subsets in CC patients has not been systemically clarified. In this study, 158 patients with metastatic CC were enrolled. Chi-square test was used to analyze the relationship between baseline peripheral blood lymphocyte subsets and clinicopathological parameters. Kaplan-Meier and Log-rank tests were used to analyze the relationship between clinicopathological parameters and baseline peripheral lymphocyte subsets and overall survival (OS) of patients with metastatic CC. Univariate/multivariate COX regression analysis was used to identify the independent factors in metastatic CC. The baseline peripheral blood CD3+T cells, CD4+T cells, NK cells and B cells of BRAF mutant patients were significantly lower than those in BRAF wild-type patients; The baseline CD8+T cells of KRAS mutation group was lower than that in KRAS wild type group. Peripheral blood CA19-9>27, left-sided colon cancer (LCC), KRAS and BRAF mutation were poor prognostic factors, and ALB>40, NK cells were protective prognostic factors for metastatic CC. In patients with liver metastases subgroup, higher NK cells also indicated a longer OS. Finally, LCC (HR=0.56), CA19-9 (HR=2.13), ALB (HR=0.46) and circulating NK cells (HR=0.55) were independent prognostic factors for metastatic CC. LCC, higher level of ALB and NK cells at baseline are protective factors, and higher CA19-9, KRAS/BRAF gene mutation are adverse prognostic factors. Sufficient circulating NK cells are independent prognostic factor for metastatic CC patients.

MMP2 is a immunotherapy related biomarker and correlated with cancer-associated fibroblasts infiltrate in melanoma

BackgroundMounting evidence supports that matrix metalloproteinase (MMPs) are highly associated with tumor progression and that targeting MMPs may overcome the barrier of immune suppression. Among these, whether MMP2 functions as an immunosuppressive role in melanoma, remains unclear.MethodsThe Cancer Genome Atlas (TCGA) and Gene Expression Profiling Interactive Analysis 2 (GEPIA2) databases were used to assess the prognosis of MMP2 in melanoma, after which Tumor immune estimation resource (TIMER) was used to explore the relationship between MMP2 expression and cancer associated fibroblasts (CAFs) infiltration. Finally, we evaluated the efficacy of MMP2 inhibitor on CAFs infiltration and immunotherapy using a mouse melanoma model.ResultsIn general, the expression of MMP2, MMP13, MMP16, MMP17 and MMP25 were significantly associated with skin cutaneous melanoma (SKCM) patients prognosis, among which MMP2 low expression benefited patients the most. Especially, the overall survival (OS) of BRAF mutation patients with high MMP2 expression was significantly lower than the MMP2 low expression group, but there was no significant difference in BRAF wild-type patients. KEGG and GO enrichment analysis indicated that MMP2 related genes were mostly associated with extracellular structure organization, collagen-containing extracellular matrix and extracellular matrix structural constituent. Furthermore, in almost all cancers, MMP2 expression was positively correlated with CAFs infiltration. MMP2 inhibitor works synergistically with PD-1 antibody and induces tumor regression in a mouse melanoma model, which is dependent on decreased CAFs infiltration.ConclusionsThis suggests that MMP2 plays a vital role in the regulation of CAFs infiltration, potentially participating in immunotherapy response, and thus representing a valuable target of immunotherapy in melanoma.

Neoadjuvant plus adjuvant combined or sequenced vemurafenib, cobimetinib and atezolizumab in patients with high-risk, resectable BRAF-mutated and wild-type melanoma: NEO-TIM, a phase II randomized non-comparative study.

Following the increased survival of patients with metastatic melanoma thanks to immunotherapy and targeted therapy, neoadjuvant approaches are being investigated to address the unmet needs of unresponsive and intolerant patients. We aim to investigate the efficacy of neoadjuvant plus adjuvant combined or sequenced vemurafenib, cobimetinib and atezolizumab in patients with high-risk, resectable BRAF-mutated and wild-type melanoma. The study is a phase II, open-label, randomized non-comparative trial in patients with stage IIIB/C/D surgically resectable, BRAF-mutated and wild-type melanoma, with three possible treatments: (1) vemurafenib 960 mg twice daily from day 1 to 42; (2) vemurafenib 720 mg twice daily from day 1 to 42; (3) cobimetinib 60 mg once daily from day 1 to 21 and from day 29 to 42; and (4) atezolizumab 840 mg for two cycles (day 22 and day 43).Patients will be randomized to three different arms: A) BRAF-mutated patients will receive over 6 weeks (1) + (3); B) BRAF-mutated patients will receive over 6 weeks (2) + (3) + (4); C) BRAF wild-type patients will receive over 6 weeks (3) + (4). All patients will also receive atezolizumab 1200 mg every 3 weeks for 17 cycles after surgery and after a second screening period (up to 6 weeks). Neoadjuvant therapy for regional metastases may improve operability and outcomes and facilitate the identification of biomarkers that can guide further lines of treatment. Patients with clinical stage III melanoma may especially benefit from neoadjuvant treatment, as the outcomes of surgery alone are very poor. It is expected that the combination of neoadjuvant and adjuvant treatment may reduce the incidence of relapse and improve survival. eudract.ema.europa.eu/protocol.htm, identifier 2018-004841-17.

Circulating IL-6 is associated with disease progression in BRAFwt metastatic melanoma patients receiving anti-PD-1 therapy

AimsDespite efficacy of anti-PD-1 blockade in treatment of metastatic melanoma (MM), many patients achieve rapid disease progression (DP). Therefore, the aim of this study is to better define biomarkers for...

Colorectal cohort analysis from the Intraperitoneal Chemotherapy After Cytoreductive Surgery for Peritoneal Metastasis (ICARuS) clinical trial.

160 Background: ICARuS is a randomized phase II, multicenter trial to evaluate the relative efficacy of Hyperthermic Intraperitoneal Chemotherapy (HIPEC) with mitomycin C vs. Early Postoperative Intraperitoneal Chemotherapy (EPIC) with floxuridine (FUDR), after cytoreductive surgery (CRS), for the treatment of peritoneal metastases (PM) from colorectal (CRC) or appendiceal cancer (AC). PRODIGE7 results failed to demonstrate benefit of HIPEC therapy after complete gross resection of CRC PM, prompting termination of CRC accrual and early cohort analysis. Methods: Patients with isolated, confirmed PM were eligible for 1:1 randomization to CRS plus HIPEC with mitomycin C or CRS plus EPIC with FUDR. Patients were stratified by recent systemic chemotherapy and disease (AC vs. CRC). The trial was originally powered to evaluate 212 patients for a 20% gain in a primary endpoint of 3-year progression free survival (PFS: HR = 1.75). Results: Seventy-five CRC patients were included between 4/2013 and 12/2018 for HIPEC (N = 40) or EPIC (N = 35) treatment. Baseline characteristics were well balanced. After a median follow up of 36 months, the median PFS was 7.7 months (95% CI: 6.3-11.1) in the HIPEC arm and 8.8 months (95% CI: 7.1-21.9) in the EPIC arm, HR = 0.69 (95% CI: 0.42-1.14) p = 0.14. In the 42 left-sided primary cancers, the median PFS was 8.4 months (95% CI: 6.4-17.7) in the HIPEC arm and 12.5 months (95% CI: 8.1-NR) in the EPIC arm, HR = 0.60 (95% CI: 0.29-1.22) p = 0.14. In the 33 right-sided primary cancers, the median PFS was 6.5 months (95% CI: 5.5-14.1) in the HIPEC arm and 8 months (95% CI: 5.8-24.1) in the EPIC arm, HR = 0.80 (95% CI: 0.39-1.64) p = 0.53. PFS was significantly better in the EPIC arm among patients with BRAF wildtype (WT) tumors and patients with higher PM burden (PCI &gt; 7). There was no difference between HIPEC and EPIC in the primary toxicity endpoint of complications grade 3 or above (23 vs. 34%, p = 0.3). Conclusions: Three-year PFS did not significantly differ between treatment arms. The lack of survival benefit of HIPEC in the entire cohort and in subset analysis is consistent with the findings of PRODIGE7. ICARuS remains open to accrual for AC. These data support further investigation of the potential benefit of EPIC with CRS in carefully selected patients with CRC PM. Clinical trial information: NCT01815359 .

RAF-Independent MEK Mutations Drive Histiocytic Neoplasms In Vivo and Are Sensitive to Single-Agent ERK Inhibition in Patients

Histiocytic neoplasms are clonal disorders of the monocyte/macrophage lineage that include Langerhans cell histiocytosis (LCH) and Erdheim-Chester disease (ECD). Histiocytoses are defined by recurrent, mutually exclusive mutations activating MAP kinase signaling, including BRAFV600E mutations in ~50% of LCH and ECD patients, which confer robust lasting clinical responses to BRAF inhibition. Mutations in MEK1/2, ARAF, and a diverse array of other kinases are present in BRAF wild-type histiocytoses patients and are broadly responsive to the allosteric MEK1/2 inhibitor cobimetinib. Following genomic analysis of ~300 pediatric and adult patients with diverse histiocytoses, the single most common genomic alteration following BRAFV600E mutations are MEK1 E102_I103 in-frame deletions. In contrast to BRAFV600E, the biological impact of activating mutations in MEK1/2 kinases are unknown, and no cancer associated MEK1/2 mutation has ever been modeled in vivo. MEK1/2 mutations are recurrent across a wide variety of human cancers and RASopathies and are now often found at resistance to emerging KRAS-mutant selective inhibitors. These findings motivated us to generate Map2k1E102_I103del conditional knock-in mice within the endogenous locus of Map2k1 (encoding MEK1 kinase), which represent the first genetically engineered mouse model of MEK1/2 mutations. We first crossed Map2k1E102_I103del mice to inducible Mx1-cre driver mice. Interestingly, Mx1-cre Map2k1E102_I103del knock-in mice developed a 100% penetrant lethal myelomonocytic disorder by 5-6 weeks of age while their cre-negative Map2k1E102_I103del littermates did not develop disease (Figure A). Notably, recombination of the Map2k1E102_I103del alleleoccurred spontaneously without pIpC administration and resulted in strong activation of phosphorylated ERK1/2 in bone marrow and spleen mononuclear cells. Mx1-cre Map2k1E102_I103del mice developed a myelomonocytic neoplasm with suppression of B-lymphopoiesis and expansion of classical and non-classical monocyte subsets, macrophages, and Cd11b+ conventional dendritic cells. Monocyte, macrophage, and dendritic cells infiltrated hematopoietic organs (bone marrow, spleen, and peripheral blood), as well as liver and skin, each of which are common sites of LCH and ECD disease involvement. The Mx1-cre Map2k1E102_I103del disease was hematopoietic cell autonomous and could be propagated by serial hematopoietic reconstitution in irradiated recipient mice, as well as using Vav1-cre Map2k1E102_I103del knock-in mice (where Cre is expressed only in hematopoietic cells from earliest hematopoietic development). Finally, restricting MEK1 mutant expression to monocyte and dendritic cell precursors using CD11c-cre resulted in similar lethal expansions of monocyte, macrophage, and dendritic cells as seen in the Mx1-cre and Vav1-cre models. Prior in vitro work has demonstrated that MEK1 p.E102_I103del activates MEK and ERK without requiring activated GTP-bound RAS and is associated with resistance to allosteric MEK inhibitors. Consistent with this, we identified nine histiocytosis patients with this specific MEK1 mutation, three of which had de novo resistance to cobimetinib. These three patients and one treatment-naïve patient were treated with an oral ERK1/2 inhibitor ulixertinib under the FDA single-patient compassionate use program. Three of 4 patients had a clinical or radiological partial or complete response to ulixertinib (Figure B). Overall, these data identify the impact of oncogenic MEK kinase mutations in vivo as found in children and adults with histiocytoses and RASopathies. Expression of a RAF-independent MEK1 mutation in vivo gave rise to disease reminiscent of human systemic histiocytic neoplasms. Importantly, this molecular entity is resistant to MEK inhibition in some patients, a phenomenon previously undocumented, but responsive to ERK inhibition, which may be a promising therapeutic approach to histiocytic neoplasms unresponsive to allosteric MEK inhibition. The clinical observation of efficacy of ERK inhibition in MEK inhibitor resistant histiocytoses patients has resulted in a soon-to-be initiated focused phase 2 clinical trial of ulixertinib in adults with histiocytoses. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Heparanase modulates the prognosis and development of BRAF V600E-mutant colorectal cancer by regulating AKT/p27Kip1/Cyclin E2 pathway

BRAF V600E-mutant colorectal cancer (CRC) is a rare subtype of colorectal cancer with poor prognosis. Compelling evidence indicates that the heparanase (HPSE) gene has multiple functions in cancer, however, its role in BRAF V600E-mutant CRC remains elusive. Differentially expressed genes between BRAF V600E-mutant and wild-type patients were explored by analyzing public data from The Cancer Genome Atlas and the Gene Expression Omnibus. Clinical samples of 172 patients with BRAF V600E-mutant CRC diagnosed at Zhongshan Hospital Fudan University were collected. Overall survival was analyzed using Kaplan–Meier curves and Cox regression models. Cell models and xenografts were utilized to investigate the effect of HPSE on tumor proliferation. HPSE was significantly highly expressed in the BRAF V600E-mutant group. High HPSE expression level was independently associated with inferior survival in the BRAF V600E-mutant cohort. HPSE knockdown impeded tumor proliferation of BRAF V600E-mutant CRC cells in vitro and in vivo. Mechanistically, HPSE silencing arrested cell cycle in G0/G1 phase by downregulating Cyclin E2 expression via the AKT/p27Kip1 pathway. These findings support a role for HPSE in promoting BRAF V600E-mutant CRC progression, which suggests it holds great promise as a prognostic biomarker and a potential therapeutic target for the aggressive CRC subtype.

364P Prevalence, treatment and survival of NTRK gene fusions in microsatellite instable metastatic colorectal cancer patients

TRK inhibitors are a treatment option for patients with NTRK fusions positive tumors, including metastatic colorectal cancer (mCRC). However, the clinical behavior, including response to standard therapy and overall survival, in NTRK fusion positive mCRC is unknown which complicates the interpretation of tumor agnostic basket trials studying TRK inhibitors. We aim to estimate the prevalence of NTRK fusions in microsatellite instable (MSI) mCRC and to determine patient characteristics and clinical behavior of this NTRK fusion subtype. FFPE tissue was requested from all MSI mCRC patients diagnosed between 2015 and 2020 in the Netherlands. Pan-Trk immunohistochemistry was used as screening method. Positive cases were analyzed by RNA-based NGS with Archer or FFPE-targeted locus capture to assess NTRK1, 2, and 3 rearrangements. Clinical data were retrieved from the Netherlands Cancer Registry. In total, 8 out of 203 tumors (3,9%) harbored an NTRK fusion: 7 rearrangements were found in the NTRK1 gene and 1 NTRK3-ETV6 fusion was detected. All NTRK-fusion positive tumors were RAS and BRAF wild-type. In the subgroup (n = 26) of RAS and BRAF wild-type MSI patients, prevalence of NTRK fusions was 23%. All NTRK-fusion positive tumors showed loss of MLH1 and PMS2 and MLH1 promotor hypermethylation was found in 7 out of 8 tumors. Benefit from chemotherapy (1/6) or anti-EGFR therapy (0/2) in NTRK-fusion positive patients was limited, but all four immunotherapy-treated patients had ongoing responses and a minimum overall survival of 470 days. The four patients who did not receive immunotherapy had a short overall survival (range 11-282 days). In this population wide cohort study, NTRK fusions are most prevalent (23%) in RAS and BRAF wild-type MSI mCRC patients. This is the first study to suggest resistance to chemotherapy and anti-EGFR therapy in NTRK-fusion positive tumors leading to impaired overall survival. In contrast, immunotherapy seems to be effective in NTRK-fusion positive patients. The clinical condition of the patient probably dictates the choice of upfront immunotherapy versus TRK inhibitors in this subgroup. We recommend early testing for NTRK fusions in RAS and BRAF wild-type MSI patients.