Growth Factor Receptor Gene Alterations Research Articles

Incidence and potential prognostic implications of fibroblast growth factor receptor gene alterations and coexisting mutations in colorectal cancer.

e15558 Background: The fibroblast growth factor receptor (FGFR) family comprises four tyrosine kinase receptors (FGFR1-4). FGFR1 amplification (6.3%) as well as overexpression of FGFR1 (10.1%), FGFR2 (5.5%) and FGFR3 (16.2%) have been demonstrated in primary colorectal cancer (CRC, incidence in brackets). The prognostic utility of testing FGFR alterations and association with response to FGFR-inhibitors are still emerging. Here, we report FGFR alteration data with clinicopathological correlations and survival outcomes from a Sydney based Local Health District in Australia. Methods: Clinicopathological data was analysed from 341 ethnically diverse patients with CRC treated at Southwestern Sydney Local Health District from 2014-2021. Next generation sequencing for point mutations, deletions, and amplifications was performed using the Qiagen 30-gene panel. Mismatch repair (MMR) status was determined using immunohistochemical staining. Demographic characteristics, histological features and survival outcomes were recorded from electronic medical records. Results: Of the 341 patients, 42 (12.3%) had FGFR alterations of which 52% were men and 48% women. 32 patients were Caucasian, 4 Middle Eastern, 5 Asian and 1 South American. Median age at diagnosis was 66 years. Of the 42 patients, FGFR1 mutations were present in 26.2%, FGFR1 amplifications in 4.7% and FGFR1 deletions in 4.7%. FGFR2 mutations were present in 16.7%, and 50% had FGFR3 mutations. One patient had concurrent FGFR1 and FGFR3 mutations. The vast majority were adenocarcinoma (81%), followed by mucinous adenocarcinoma (17%) and adenocarcinoma with neuroendocrine features (2%). 21.4% of patients with FGFR alterations had concurrent KRAS mutations, 28.6% had concurrent BRAF mutations (91.6% V600E) and MMR-deficiency was present in 19%. Median overall survival of patients with FGFR alterations was 44 months, for those who also had deficient MMR 48 months, concurrent BRAF V600E mutations 51 months and concurrent KRAS mutations 71 months. 43% (18 patients) were stage 4 at presentation. Of these 18 patients, 7 had FGFR1 mutations, 1 had a FGFR2 mutation and 10 had FGFR3 mutations. The median overall survival of patients with stage 4 disease was 11 months and those with concurrent BRAF V600E mutations 17 months. Two patients had concurrent KRAS mutations (both G12V), with median overall survival of 5.5 months and 1 patient had MMR deficiency, with an overall survival of 9 months. Conclusions: FGFR alterations were identified in 12.3% of patients with colorectal cancer in an ethnically diverse cohort in Australia. Concurrent KRAS and BRAF mutations appear to affect survival outcomes. Further multivariate analyses are underway.

Prognostic Value of Fibroblast Growth Factor Receptor Genetic Alterations in Metastatic Urothelial Carcinoma

IntroductionEvidence is limited on whether fibroblast growth factor receptor gene alterations (FGFRalt) impact clinical outcomes in patients with locally advanced or metastatic urothelial cancer (mUC). This study evaluated progression-free survival (PFS) in patients with mUC based on FGFRalt status in the first-line setting (1L). Patients and methodsData on mUC patients were retrieved via convenience sampling of oncologists/urologists surveyed between August and September 2020 who treated at least 1 FGFRalt patient between July 2017 and June 2019. The questionnaire included information on patient demographics, FGFR status, treatment, and clinical and radiographic measures of progression.Primary endpoint was time from metastatic diagnosis to disease progression from initial treatment for FGFRalt and FGFRwt (wild-type) mUC. Cox proportional hazards models quantified adjusted risk of FGFR status relating to PFS. ResultsA total of 414 patients were analyzed. Mean age was 64.5 years, 73.9% were male, and 52.7% had an FGFRalt. Among FGFRalt, 47.2% received chemotherapy, 27.5% immune checkpoint inhibition (ICI), 11.5% chemotherapy+ICI, and 13.8% other treatments in 1L. FGFR status did not influence PFS from time of mUC diagnosis or among 224 stratified patients receiving either chemotherapy or chemotherapy+ICI. However, among 97 patients with an FGFRalt receiving 1L ICI therapy only, adjusted risk of progression was twice that of FGFRwt (HR: 2.12; 95% CI: 1.13-4.00). ConclusionAlthough FGFRalt did not predict outcomes in the overall cohort, for patients treated with 1L ICI, FGFRalt had significantly higher rates of progression than FGFRwt patients. Further validation is needed to determine whether FGFRalt has a decreased benefit from ICI therapy.

Global Expanded Access Program for Pemigatinib in Patients with Previously Treated Locally Advanced or Metastatic Cholangiocarcinoma and Fibroblast Growth Factor Receptor Gene Alterations.

Pemigatinib is a fibroblast growth factor receptor-2 (FGFR2) inhibitor approved for use in patients with previously treated cholangiocarcinoma (CCA) and FGFR2 fusions or rearrangements. This ongoing global Expanded Access Program (EAP) allows physicians in regions where pemigatinib is not commercially available to request pemigatinib for patients with locally advanced or metastatic CCA who, in the physician's opinion, could benefit from pemigatinib treatment. Eighty-nine patients from Europe, North America, and Israel were treated from January 2020 through September 2021. Patients had FGFR gene fusions (68.5%), rearrangements (12.4%), translocations (5.6%), amplifications (2.2%), and other alterations (11.2%). Median duration of treatment in the EAP was 4.0 months (range, 0.1 to 13.6 months). The most frequently reported adverse event (AE) was hyperphosphatemia (22.5%); the most common serious AE was cholangitis (3.4%). Treatment discontinuation was associated with reports of AEs for seven patients (7.9%). AEs associated with pemigatinib were consistent with those observed in clinical trials. Efficacy was not assessed in this EAP. However, some patients remained on treatment for up to a year, suggesting that they observed a benefit from treatment. Patients with CCA should undergo molecular testing to identify those who could benefit from targeted treatments such as pemigatinib.

P10.14.B PROGRESSION OF IDH-MUTANT ASTROCYTOMAS TO GRADE 4 UNDER TREATMENT-RELATED SELECTION PRESSURE

Abstract BACKGROUND The progression of low-grade diffuse astrocytomas into grade 4 tumors significantly impacts patient prognosis, therefore a better understanding of this process is of paramount importance for improved patient care. MATERIAL AND METHODS We analyzed next-generation sequencing data from matched IDH-mutant astrocytomas before and after progression to grade 4 from up to 27 patients as well as publicly available The Cancer Genome Atlas (TCGA) data from up to 595 cases. All patients in our discovery cohort with genome-wide sequencing data received radiation, all but one underwent chemotherapy, and no patient received temozolomide before progression to grade 4. RESULTS One case in the discovery cohort exhibited a hypermutation signature associated with inactivation of the MSH2 and DNMT3A genes. In other patients, the number of novel chromosomal rearrangements and deletions increased in grade 4 tumors. Tumor progression was associated with upregulated cell cycle progression, migration, and DNA damage repair-related genes. Upon progression, the cell cycle checkpoint genes CDKN2A or RB1 were most commonly inactivated, especially after postoperative radiation and chemotherapy, followed by activating growth factor receptor gene alterations in cases with homozygous CDKN2A deletion. We also detected alterations in DNA repair pathway genes associated with therapy resistance and the promotion of error-prone DNA repair, thus facilitating tumor progression. The homologous recombination repair gene RAD51B was hemizygously deleted in all but one progressed tumor in our discovery cohort. In our retrospective nonrandomized survival analysis, treatment including both radio- and chemotherapy improved relapse-free and overall survival compared to other treatments in cases with primary grade 3 diagnosis. Similar benefit was not observed for cases with primary grade 2 diagnosis, and radiation as sole postoperative treatment was not significantly improving the prognosis in any of the analyses. CONCLUSION Our results support the previous notions that treatment-induced DNA damage can contribute to tumor progression to grade 4 and suggest that altered DNA repair has a role in treatment resistance and tumor progression.

Outcomes of Patients with Advanced Urothelial Carcinoma after Anti–programmed Death-(ligand) 1 Therapy by Fibroblast Growth Factor Receptor Gene Alteration Status: An Observational Study

BackgroundClinical outcomes of anti–programmed death‑(ligand) 1 (anti–PD-[L]1) therapy in patients with locally advanced or metastatic urothelial carcinoma (mUC) and fibroblast growth factor receptor alterations (FGFRa+) remain unclear; recent studies have reported either comparable or poorer outcomes versus patients without FGFR alterations (FGFRa–). ObjectiveTo analyze the outcomes of patients with mUC and any FGFRa (mutations or fusions) who received anti–PD-(L)1 therapy. Design, setting, and participantsIn this noninterventional, retrospective, multicenter study, clinical practice data were collected from FGFRa+/– patients who received prior immunotherapy between May 2018 and July 2019. Outcome measurements and statistical analysisInvestigator‑determined overall response rate (ORR), disease control rate (DCR), and overall survival (OS) were assessed in multivariate and unadjusted analyses. Results and limitationsNinety-four patients (66% men; median age, 63 yr) with mUC and known FGFR status were included; 38 (40%) were FGFRa+ and 56 (60%) were FGFRa–. In FGFRa+ versus FGFRa– patients who received any line of anti–PD-(L)1 therapy (n = 92), ORR, DCR, and OS were 16% versus 26%, 29% versus 52% (relative risk: 1.14 [95% confidence interval {CI}, 0.92–1.40]; p = 0.3), and 8.57 versus 13.2 mo (hazard ratio [HR]: 1.33 [95% CI, 0.77–2.30]; p = 0.3), respectively. A multivariate analysis provided some evidence supporting shorter OS in FGFRa+ versus FGFRa– (any line of anti–PD-L[1] therapy; HR: 1.81 [95% CI, 0.99–3.31]; p = 0.054). Limitations include this study’s retrospective nature and a potential selection bias from small sample size. ConclusionsSome evidence of lower response rates and shortened OS following anti–PD-(L)1 therapy was observed in FGFRa+ patients. The phase 3 THOR study (NCT03390504) will prospectively compare FGFRa+ patients with advanced mUC treated with erdafitinib versus pembrolizumab. Patient summaryPatients with metastatic urothelial carcinoma and prespecified fibroblast growth factor receptor alterations (FGFRa) potentially have worse clinical outcomes when treated with anti–PD-(L)1 therapy than those without FGFRa.

Clinicopathologic outcomes of preoperative targeted therapy in patients with clinical stage I to III non–small cell lung cancer

ObjectiveTargeted therapy improves outcomes in patients with advanced-stage non–small cell lung cancer (NSCLC) and in the adjuvant setting, but data on its use before surgery are limited. We sought to investigate the safety and feasibility of preoperative targeted therapy in patients with operable NSCLC. MethodsWe retrospectively reviewed 51 patients with clinical stage I to III NSCLC who received targeted therapy, alone or in combination with chemotherapy, before surgical resection with curative intent, treated from 2004 to 2021. The primary outcome was the safety and feasibility of preoperative targeted therapy; secondary outcomes included objective response rate, major pathologic response (defined as ≤10% viable tumor) rate, recurrence-free survival (RFS), and overall survival. ResultsOf the 51 patients included, 46 had an activating epidermal growth factor receptor gene alteration and 5 had an anaplastic lymphoma kinase fusion. Overall, 37 of 46 evaluable patients experienced at least 1 adverse event before surgery; however, only 3 patients experienced a grade 3 or 4 event. The objective response rate was 38% (17/45) for all evaluable patients and 44% (14/32) for patients with clinical stage II or III disease. The major pathologic response rate was 20% (9/44); 2 patients had a complete pathologic response. Median RFS was 3.8 years (95% CI, 2.8 to not reached). Targeted therapy alone was associated with better RFS than combination therapy (P = .009) in patients with clinical stage II or III disease. ConclusionsPreoperative targeted therapy was well tolerated and associated with good outcomes, with or without induction chemotherapy. In addition, radiographic response and pathologic response were strongly correlated.

Fibroblast growth factor receptor 2 (FGFR2) fusions in Japanese patients with intrahepatic cholangiocarcinoma.

ObjectiveFibroblast growth factor receptor gene alterations have emerged as promising drug targets for intrahepatic cholangiocarcinoma, a rare cancer that has a poor prognosis. This study evaluated the frequency of fibroblast growth factor receptor 2 fusions in clinical specimens from Japanese patients with iCCA.MethodsThis study enrolled 116 patients who had histologically or cytologically confirmed adenocarcinoma and been diagnosed as relapsing after resection or with unresectable intrahepatic cholangiocarcinoma. We evaluated the frequency of fibroblast growth factor receptor 2 fusions-positive cells in their specimens using break-apart fluorescent in situ hybridization ‘for 114 patients who met the study protocol’.ResultsOf a total of 114 cases, six (5.3%) were identified as fibroblast growth factor receptor 2 fusions-positive with a high frequency (87% or more) of fibroblast growth factor receptor 2 fusions-positive tumour cells whereas the remainder, with the exception of three cases with indeterminate results, were identified as fibroblast growth factor receptor 2 fusions-negative. The patients’ baseline characteristics as well as their objective response rates, disease control rates, times to progression, and times to treatment failure with previous or ongoing first-line chemotherapy did not have any obvious relationship to the proportion of fibroblast growth factor receptor 2 fusions-positive case.ConclusionsFurther detailed elucidation of fibroblast growth factor receptor 2 fusion status is expected to contribute to the development of promising therapeutic options for patients suffering from recurrent or unresectable intrahepatic cholangiocarcinoma.

Rare epidermal growth factor receptor gene alterations in non-small cell lung cancer patients, tyrosine kinase inhibitor response and outcome analysis

BackgroundThe predictive value of rare epidermal growth factor receptor gene (EGFR) mutations for non-small cell lung carcinoma (NSCLC) patients remain elusive. We evaluated the distribution, clinicopathological association, tyrosine kinase inhibitor (TKI) response, and outcome of NSCLC patients carrying uncommon EGFR aberrations in comparison to classical EGFR mutations. MethodsTreatment naïve, advanced NSCLC cases tested by Next-Generation sequencing (NGS) method between 2015 and 2020 were included. The objective response rate (ORR), disease control rate (DCR), progression-free survival (PFS), and overall survival (OS) were analyzed. ResultsA total of 237 tumor samples were sequenced. Among the sixty-nine (29%) EGFR mutated cases, 41 (59.4%) harbored classical mutation (37.7% Del19, 21.7% p.L858R). Non-classical aberrations included missense mutations in exon 18/20/21 (15.9%), EGFR amplification (8.7%), exon 20 insertions (7.2%), EGFR Variant III (4.3%), exon 18 indel (2.9%), exon 21 missense (2.9%) and exon 19 missense mutation (1.4%). These occurred as complex mutations in 16% of cases. Oral TKI was administered in 66.7% cases. The patients harboring non-classical variants had a lower ORR and DCR (23.1% and 61.5%) than those carrying a common mutation (57.6% and 84.8%). Collectively, compared to the patients with common EGFR mutations, the uncommon group showed early disease progression and had shorter overall survival. ConclusionNGS testing has the capacity to reveal a diverse spectrum of uncommon EGFR variants. Our study can contribute to the database of uncommon EGFR mutations with a positive influence on evidence-based care of advanced lung cancer patients with EGFR mutations.

757P An observational study of outcomes of patients (pts) with advanced urothelial carcinoma (UC) after anti-programmed death-(Ligand) 1 (PD-[L]1) therapy by fibroblast growth factor receptor gene alteration (FGFRa) status

757P An observational study of outcomes of patients (pts) with advanced urothelial carcinoma (UC) after anti-programmed death-(Ligand) 1 (PD-[L]1) therapy by fibroblast growth factor receptor gene alteration (FGFRa) status

Evaluation of epidermal growth factor receptor gene and chromosome 7 alterations in squamous cell carcinoma of the larynx, using chromogenic in situ hybridization on tissue microarrays

To identify subgroups of patients with squamous cell carcinoma (SCC) of the larynx, characterized by the specific deregulation mechanism of the epidermal growth factor receptor (EGFR) gene, and to evaluate EGFR protein expression levels and correlate these with biological and clinicopathological parameters. Using tissue microarray technology, 50 formalin-fixed, paraffin-embedded primary laryngeal SCCs were cored and re-embedded into one block. Immunohistochemistry and chromogenic in situ hybridization were performed. Epidermal growth factor receptor protein over-expression was observed in 27/50 (54 per cent) cases and was statistically associated with tumour grade (p=0.028). Epidermal growth factor receptor gene alterations were identified in 5/50 (10 per cent) cases, which demonstrated amplification (n=4) and deletion (n=1). Chromosome 7 instability was detected in 8/50 (16 per cent) cases. Epidermal growth factor receptor over-expression is a frequent event in SCCs, but it does not predict a specific molecular mechanism of gene deregulation for targeted therapeutic strategies via monoclonal antibodies.