Clinicopathologic and mutational landscape of BRAFV600E-mutant non–small cell lung carcinoma

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Background: BRAF mutations (mts) occur in 2-5% of non-small cell lung cancers (NSCLC) with approximately 50% being BRAFV600E. Limited data is known regarding the mutational landscape (ML) and prognostic role of co-mutations in BRAFV600E NSCLC. We performed this study to evaluate clinicopathological characteristics and the impact of ML in BRAFV600E NSCLC. Methods: Patients (pts) with BRAFV600Emutant NSCLC were identified using MSK-IMPACT at Memorial Sloan Kettering Cancer Center between January 2014 to October 2021. Baseline clinicopathological characteristics and treatment outcomes were annotated. Due to the enrichment of SETD2 in BRAFV600E NSCLC, we conducted further analyses using cbioportal to identify co-mutations of SETD2 with other actionable mutations in NSCLC. Overall survival (OS) was assessed from the date of metastatic disease until death using the log-rank test. Results: BRAF mutations were detected in 5% of NSCLC samples (512/10220) with 22% (97/435 pts) being BRAFV600E. Of the 97 pts with BRAFV600E NSCLC identified: 57 pts (59%) were females, median age of 68 (range: 38-93 years), 58 pts (60%) were former smokers. All BRAFV600E tumors were adenocarcinoma and the median tumor mutational burden was 5 mt/Mb (range: 0-40). 46 pts (48%) with BRAFV600E NSCLC were diagnosed with de novo metastatic disease. Pts receiving targeted therapy at first, second, and subsequent lines of therapy numbered 17 (29%), 18 (31%), and 10 (17%) respectively. Co-alterations of BRAFV600E with TP53 and SETD2 were found in 45% (44/97) and 42% (41/97), respectively. There is a much lower prevalence of concurrent inactivating SETD2 mutations than with other actionable alterations in NSCLC: ROS1 (9%), ALK (8%), RET (8%), HER2 (6%), MET (5%), KRAS (5%), EGFR (2.9%) and BRAFnon-V600E (2%). Median OS in BRAFV600E+/ TP53+ vs BRAFV600E+/ SETD2+ were 35 vs 36 mos (HR 0.88m 95% CI 0.45-1.75, P= 0.71) and BRAFV600E+/ TP53+/ SETD2+ vs BRAFV600E+/ TP53-/ SETD2- were 19 vs 39 mos (HR 0.37, 95% CI 0.09-1.50, P= 0.06). Conclusions: Among the BRAFV600E lung adenocarcinomas, concurrent TP53 mutation and SETD2 inactivation define a patient subset with significantly shorter overall survival. Further studies are warranted to investigate the role of SETD2 mutations in the context of BRAFV600E in NSCLC pts.

Mucinous colorectal cancer: Disease characteristics, treatment outcomes and the impact of metastasectomy

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Background: Mucinous colorectal cancer (CRC) differs from adenocarcinoma with regard to clinical and histological features and is reported to have inferior outcomes when compared to non-mucinous CRC. This study aims to evaluate the clinical features and outcomes of patients with mucinous CRC at our institution. Methods: Medical records of patients with CRC that were referred to medical oncology between September 1999 and September 2018 were retrospectively reviewed. Mucinous histology was defined as those containing > 50% mucin identified on histology specimens. Statistical analysis was performed using Prism V9.0. Results: We identified 1,115 patients with CRC that were referred to medical oncology during this period. The tumours of 81 (7.3%) patients were classified as mucinous. Median age was 65 (28-94 years) and 45 (55.5%) were male. Forty-one patients (51%) had right sided tumours, 27 (33%) had left sided tumours and 13 (16%) had rectal tumours. Twenty-three (28.4%) had de novo metastatic disease. Eleven of 24 patients (46%) with stage II disease relapsed and 18 of 33 (55%) of those with stage III disease relapsed. Radiological surveillance identified 20/29 (69%) of relapsed disease, 5 (17%) were symptomatic and 4 (14%) had a rise in CEA. Median follow up for patients with stage II disease was 53 months and 3 year and 5-year disease free survival (DFS) was equal in both groups at 60.9%. For stage III disease 3- and 5-year DFS was 58.1% and 48.4% respectively with a median follow up of 43 months. In the metastatic setting, we observed no significant difference in overall survival (OS) between left and right sided tumours ( p = 0.550). Median OS for pts with stage IV mucinous CRC who received any treatment was 25 months. Metastasectomy was performed in 25/52 (48%) patients and was associated with a significant improvement in OS, 23 vs 51 months ( p < 0.005, HR 0.4). Conclusions: Mucinous CRC has been associated with inferior responses to treatment and worse overall outcomes compared to non-mucinous histologies. Survival in advanced-stage disease in our cohort is higher than what has been reported in the literature. With an effective multi-disciplinary approach and the increasing use of metastasectomy as a treatment option, survival in the advanced disease setting may be comparable to non-mucinous CRC.

Adjuvant chemotherapy (AC) for stage III colorectal cancer (CRC) in the elderly: An Irish experience

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Background: Since 2004 6 months of adjuvant Oxaliplatin containing regimens (OCR) has been standard of care for Stage III CRC despite cumulative neurotoxicity. The IDEA collaboration evaluated 3 versus 6 months of OCR in high/low risk pts with regard to peripheral neuropathy (PN) and efficacy.The median pt age was 64; individual studies included pts ≤85. Methods: This study is part of a retrospective review of the clinicopathological records of consecutive CRC pts referred to the multi-disciplinary CRC team at an Irish tertiary referral centre from 2002-2018. We recorded pt characteristics, Rx received and outcomes. Overall Survival (OS) was assessed using Kaplan-Meier analysis. Results: 869 pts were identified; 37% (328) female. 63% (551/869) < 70 and 37% (318/869) ≥ 70. Median OS for < 70 cohort was 31.5 months versus 19 months in ≥ 70 cohort (p < 0.0001).Stage distribution in < 70: ≥70 cohorts was Stage II 14%( 79/551):20% (63/318), Stage III 47% (260/55):46% (142/318) and Stage IV 38% (207/551):34% (111/318). In < 70 Stage III cohort 7% (37/551) pts received no AC, 42%(230/551) received FOLFOX, 3%(16/551) received FLOX or XELOX, 7%(38/551) received 5FU/LEU. 32%(78/246) of pts < 70 developed PN with persistence at 6 months in 18%(44/256). In ≥ 70 Stage III cohort 58%(83/142) did not received AC. 23%(32/142) received an OCR and 16%(23/142) received 5FU/LEU; there was a statistically significant survival difference with an OCR. 47% (15/32) of pts ≥70 receiving OCR developed PN which persisted at 6 months in 28% (9/32). In < 70 cohort there was no significant survival difference in the IDEA-trial-defined low risk group between 12 versus < 12 FOLFOX. There was a numerical survival difference in the < 70 high risk group between 12 versus < 12 FOLFOX; this was not statistically significant. In the ≥70 age group there was no survival difference in either IDEA risk groups for 12 versus < 12 FOLFOX. Conclusions: > 50% of Stage III CRC patients ≥ 70 did not receive AC. OCRs were associated with a significant OS improvement but with higher PN than in < 70 cohort and higher persistence at 6 months. Irrespective of IDEA-defined risk groups,there was no statistically significant survival difference for Stage III CRC ≥70 receiving 12 versus < 12 FOLFOX.

Neutrophil to Lymphocyte ratio (NLR): A prognostic marker in melanoma patients receiving immunotherapy

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Background: Cancer related inflammatory processes have been shown to have an important role in tumourigenesis, disease progression, and patient prognosis. An elevated neutrophil to lymphocyte ratio (NLR) is associated with a worse outcome in several malignancies. The relationship between NLR and immune checkpoint blockade is poorly understood. We sought to investigate the role of NLR in patients receiving immune checkpoint inhibitors for metastatic melanoma (MM). We aimed to do this by comparing outcomes of patients with MM with high ( > 3) and low ( < 3) NLRs receiving immunotherapy, and investigating whether NLR acts as a prognostic biomarker. Methods: We performed a retrospective review of electronic medical records and collected data on 40 patients with MM treated with immunotherapy from 2013 to 2018 in MMUH, Dublin. NLR was defined as absolute neutrophil count divided by absolute lymphocyte count. Continuous variables were expressed as a median. We examined NLR at baseline and at 6 weeks (+-2 weeks). We also examined percentage change in NLR. These parameters were tested for association with PFS and OS using the log rank test. Results: 40 patients received immune checkpoint inhibitors in the form of ipilimumab, nivolumab, and pembrolizumab. The median age was 61.2 ( 29.7 to 77.1). The median baseline NLR was 3.39 ( 1.05 to 26.03). The median NLR at 6 weeks (+-2 weeks) was 2.86 ( 0.83 to 19.9). The median change in NLR was -8.02% (- 80.99% to 409.38%). Median time to progression was 4.7 months (0.4 to 51.4 months). Overall survival was 12.9 months (0.4 to 67.7 months). When baseline NLR < 3 patients had a significantly longer PFS: 11.7 vs 2.8 months (p = 0.02). When NLR at approximately 6 weeks was < 3, patients also had significantly longer PFS: 10.8 vs 2.9 months (p = 0.04). When NLR decreased by > 20% from baseline, there was no significant difference in PFS (p = 0.82). When NLR < 3, patients had significantly longer OS: 18 months vs 8.2 months (p = 0.02). When NLR at approximately 6 weeks was < 3, patients had significantly longer OS: 20.3 months vs 7.4 months (p = 0.003). Conclusions: Baseline NLR < 3 and NLR < 3 approximately 6 weeks after initiation of treatment is associated with improved PFS and OS. Change in NLR after initiation of treatment is not significantly associated with improved outcomes, however our sample size was small. NLR may be used as a readily available and cheap prognostic marker in MM patients receiving immunotherapy.

Impact and correlation of mutational load (ML) and specific mutations (mts) assessed by limited targeted profiling (LTP) with PD-L1 tumour expression (exp) in resected non-small cell lung carcinoma (NSCLC)

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Background: The advent of immunotherapy represents a paradigm shift in the treatment of NSCLC compared to conventional chemotherapy. Recent studies have shown higher mts burden assessed by exome sequencing are associated with improved objective response and clinical benefit. We performed this study to evaluate the impact of ML assessment by LTP, correlating with PD-L1 exp and clinicopathological variables in resected NSCLC. Methods: NSCLC patients(pts) who underwent curative resection between 1998 and 2006 at our institution were included. PD-L1 status was assessed using Ventana SP124 antibody on archival FFPE surgical tumour specimens cores. PD-L1 was scored positive if membranous staining was present in >1% of tumour cells aggregated across the replicate cores to address heterogeneity. In collaboration with the Lung Cancer Genomics Ireland Study a targeted panel of 49 genes were assessed by Sequenom MassArray including genes in MAPK and PI3K pathways. Clinical data was obtained from hospital electronic database. Results: Ninety-one pts were included, of which 51 (56.0%) were males, with a median age of 65 years (range: 42 – 82). 51.6%, n=47 with squamous histological subtypes, 46.2%, n=42 were ex-smoker and 49.5%, n=45 had Stage I disease. 23.1%, n=21 had PD-L1 positivity. 149 mts were identified of which, 32(21.5%) with PHLPP2, 31(20.9%) with PIK3R1 and 21(14.1%) with TP53. The presence of PI3K and TP53 mts are associated with positive PD-L1 status (see table). An inverse correlation of PD-L1 positivity with ML of (1 vs 2 vs 3: 53.8% vs 30.8% vs 15.4%) was noted. Conclusions: We did not identify higher PD-L1 exp with higher ML assessed by a LTP widely used in clincial practice. However, positive PD-L1 exp was correlated with PIK3R1 and TP53 mts , warranting further investigation as potential modulators or surrogates of positve PD-L1 expression. [Table: see text]

Clinical utility of Oncotype DX in early stage colon cancer

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Background: With the advent of colon cancer screening, patients with early stage colon cancer will be more common in our clinics. The evidence supporting the absolute benefit of chemotherapy in resected Stage II and (to a lesser extent) Stage IIIA disease is poor. Not all patients benefit from chemotherapy and toxicity is a problem. There is a need for validated biomarkers to assess individual patient recurrence risk and discriminate absolute treatment benefit. Several studies have validated the role of the OncotypeDX testing in Stage II/IIIA disease. Our objective is to characterize whether this test impacted oncologists’ decisions in treating patients with Stage II/IIIA in the adjuvant setting. Methods: :The Onco typeDX assay is a multi-gene reverse-transcriptase-polymerase-chain-reaction test that analyses the expression of 12 genes involved in key biologic pathways in colon cancer. Stage II and Stage IIIA colon cancers were studied in affiliated hospitals of our region in southwest Ireland. All data collected is prospective and each colon cancer was assigned a recurrence risk score. Oncologists were blinded to this score and the decision to prescribe adjuvant chemotherapy was recorded. After un-blinding the score, a second decision was recorded and comparisons made. Results: :From August 2015 to September 2016, 70 patients have been recruited with M: F of 2:1. Median age at diagnosis was 65 years. Most patients (80%) had stage II disease, 11 of whom had mismatch repair loss on IHC. OncotypeDX testing has been carried out and reported for 59 patients (85%), MMR intact. Recurrence scores: < 30 in 46 patients (77.9%), 30-40 in 10 patients, and > 40 in 3 patients. The treatment plan was altered in 16 patients (27%), of whom 12 patients (20%) received none or less intense chemotherapy. Conclusions: We have shown that the decision to prescribe adjuvant chemotherapy was changed in 27% of patients. This test has helped to define patients with low scores, where chemotherapy-related toxicity is a concern especially in older patients. Absolute benefit of adjuvant chemotherapy versus the risk of toxicity should be discussed. . Hospital managers may be interested in cost savings due to a reduction in chemotherapy use.

Response to tyrosine kinase inhibitors (TKIs) in non-small cell lung cancer (NSCLC) patients with de novo epidermal growth factor receptor (EGFR) T790M and S768I resistance mutations

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Background: Patients with synchronous de novo EGFR sensitising and resistance mutations are rare. Little is known about the response of these patients to EGFR TKIs, especially in a Caucasian population. Methods: We identified NSCLC patients found to have EGFR mutations using PCR-based fragment length analysis, mass spectrometry-based genotyping (Sequenom), and Sanger sequencing using a large multi-institutional database. Baseline clinical characteristics, response rate, progression free survival (PFS) and overall survival (OS) were calculated. Results: From 2008-2015, we observed de novo synchronous EGFR sensitising and resistance mutations in 12 patients representing an overall incidence of 3.6% of EGFR mutants and 0.4% of all NSCLC patients tested. Seven patients were treated using EGFR TKI therapy with erlotinib. In all cases, T790M (n = 4,50%) or S768I (n = 4, 50%) occurred concurrently with another sensitising EGFR mutation, either L858R (n = 4, 34%) or exon 19 deletion (n = 8, 66%). Objective responses were seen in two patients (29%). Three further patients had stable disease lasting 6, 23 and 54 months respectively. The median progression-free survival was 24 months and the median overall survival was 34 months. All patients with baseline EGFR S768I mutations (n = 3) had an objective response or stable disease on erlotinib while two of four patients with T790M demonstrated de novo resistance. Conclusions: This is the largest Irish review of synchronous de novo EGFR mutations. The incidence of co-occurring EGFR mutations was 0.4% and erlotinib demonstrated activity in this cohort of patients. Ongoing trials will determine whether next-generation EGFR TKIs such as osimertinib are preferable as first-line therapy in these patients.

Inappropriate prescribing in older patients with cancer

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Background: Inappropriate medication use is common among community dwelling and hospitalized older adults but understudied in the oncology population. We measured the incidence of inappropriate prescribing among older cancer patients attending an oncology day-ward for systemic therapy. Methods: The tools used to identify inappropriate prescribing were the Beers’ criteria (both Independent [ID] of and Considering diagnosis [CD] – 2012 version) and the STOPP tool (Screening Tool of Older People’s potentially inappropriate Prescriptions). The setting was an urban based hospital oncology day-ward. Consecutive subjects ≥ 70 years were screened and all had both tools applied to their prescription drugs, cross referenced with their current active medical diagnosis. Results: Medication lists were collected from 96 patients from November 1st 2012 to January 31st2013: 52% male, mean age 75 years (range 70-88). The most common cancers were colorectal (24%), breast (23%), lung (11%) and prostate (11%). 38 patients (40%) were on 0-4, 49 (51%) on 5-9 and 9 (9%) on >9 medications. The total number of inappropriate prescriptions (Beers ID and CD “medications to avoid”) was 34, prescribed in 29 (30%) patients. The most common drug prescribed inappropriately as per these criteria was the antiemetic, metoclopramide (n=10, 29%). An additional 70 prescriptions were dispensed for Beers “medications to use with caution” in 55 (57%) patients - predominantly vasodilators. The STOPP tool identified 13 inappropriate prescriptions in 12 patients (13%). The two most commonly prescribed inappropriate medications were long acting benzodiazepines (n=4) and long term use of sedating antihistamines (n=3). Conclusions: This study identified a high rate of inappropriate prescribing among this population using both tools, with a higher rate identified by the Beers Criteria. Routine application of a validated tool to identify inappropriate prescribing has merit in the oncology setting to minimize risk to patients. However, the development of an easy to apply tool that considers the underlying cancer diagnosis, prognosis, cancer treatment and necessary supportive therapy is warranted.

Uptake of adjuvant chemotherapy (AC) for colon cancer in older and younger patients (pts) in the Irish population

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Background: The use of AC in older patients with colon cancer in clinical practice is uncertain. We examined uptake of AC and it’s impact on survival in older pts with stage II and III colon cancer in a national cohort. Methods: Using the National cancer Registry of Ireland, 3,486 pts with stage II and III colon cancer treated with curative resection from 2004-2009 were identified. Clinopathological features and AC use were compared between those ≥70 yrs and those < 70 yrs. Data from a single institution were reviewed to determine drivers of treatment decisions. Results: 2,026 pts with stage II disease were identified, 60% ≥ 70 yrs. AC was utilized in 10% and 40% of ≥ 70 and <70 yrs, respectively (p<0.0001). A benefit for AC over observation was seen in older [HR 0.36; p <0.0001] and younger pts [HR 0.43; p<0.0004]. Of 46 stage II pts from a single institution there were no significant differences between ≥ 70yrs (n=26) and <70yrs (n=23) in terms of ECOG PS, Charlson comorbidity scores (CCI), tumor grade, T3/T4 disease, R0/R1 resections, obstruction/perforation, lymphovascular invasion or nodal yield. However, only 12% ≥ 70yrs received AC compared to 57% of <70yrs (p=0.0002). Of 1,460 pts with stage III disease, 51% were ≥ 70 yrs. 34% of older and 83% of younger pts received AC (p<0.0001). A benefit from AC compared to observation was seen in pts ≥ 70yrs [HR 0.30; p <0.0001] and <70yrs [HR 0.22; p<0.0001]. Of 65 stage III pts from the single institution there were no differences in CCI, ECOG PS, tumor grade, R0/R1 resections between >70yrs (n=20) and <70yrs (n=45). There was a difference in those receiving AC: 75% ≥ 70yrs compared to 96% <70yrs (p=0.02). Conclusions: Adoption of AC is associated with a survival benefit in older pts (age ≥ 70 yrs), however, is still underutilized in clinical practice. Age impacts the decision to treat in our cohort.