Real-World Analysis of the Clinical and Economic Impact of the 21-Gene Recurrence Score (RS) in Invasive Lobular Early-Stage Breast Carcinoma in Ireland

Background: This study, using real-world data, assesses the impact of RS testing on treatment pathways and the associated economic consequences of such testing. This paper pertains to lobular breast cancer. Methods: A retrospective, observational study was undertaken between 2011 and 2019 on a cross-section of hormone receptor-positive (HR+), HER2-negative, lymph node-negative, early-stage breast cancer patients. All patients had ILC and had RS testing in Ireland. The patient population is representative of the national population. Patients were classified as low (RS ≤ 25) or high (RS > 25) risk. Patients aged ≤50 were stratified as low (RS 0-15), intermediate (RS 16-25), or high risk (RS > 25). Results: A total of 168 patients were included, most of whom had grade 2 (G2) tumors (n = 154, 92%). Overall, 155 patients (92.3%) had low RS (≤25), 12 (7.1%) had high RS (>25), and 1 (0.6%) had unknown RS status. In 29 (17.5%) patients aged ≤50 at diagnosis, RS was ≤15 in 16 (55%), 16-20 in 6 (21%), 21-25 in 5 (17%), >25 in 1 (3.5%), and unknown in 1 (3.5%). Post RS testing, 126 patients (78%) had a change in chemotherapy recommendation; all to hormone therapy. In total, only 35 patients (22%) received chemotherapy. RS testing achieved a 75% reduction in chemotherapy use, resulting in savings of €921,543.84 in treatment costs, and net savings of €387,283.84. Conclusions: The use of this test resulted in a 75% reduction in chemotherapy and a significant cost savings in our publicly funded health system.

Real-world analysis of clinical and economic impact of 21-gene recurrence score (RS) testing in early-stage breast cancer (ESBC) in Ireland

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Background: Treatment of hormone receptor positive (HR+) ESBC is evolving. The use of chemotherapy (CT) is declining with use of the 21-gene RS assay. This validated tool predicts the likelihood of adjuvant CT benefit in HR+ ESBC. Results from the TAILOR-x study suggest up to 70% of HR+ node negative ESBC patients (pts) may avoid CT with RS ≤25. Our objectives were to assess the clinical and economic impact of RS testing on treatment decisions using real-world data. Methods: From October 2011 to February 2019, a retrospective, cross-sectional observational study was conducted of HR+ node negative ESBC pts who had RS testing in Ireland. A survey of Irish breast medical oncologists provided the assumption for the decision impact analysis that grade (G) 1 pts would not receive CT pre RS testing and G2/3 pts would receive CT. Using TAILOR-x results, pts were classified low risk (RS ≤ 25) and high risk (RS > 25). Data was collected via electronic patient records. Descriptive statistics were used. Cost data was obtained via the National Healthcare Pricing Regulatory Authority. The economic analysis was adjusted for changing treatment and assay costs over the study period. Results: 963pts were identified. Mean age 56 years. Mean tumour size 1.87cm. 114 (11.8%), 636(66%), 211(22%), 2(0.2%) pts had G1, G2, G3 and unknown G respectively (resp). 797pts (82.8%) had low RS, 159 (16.5%) had high RS, and 7pts(0.7%) unknown RS. 251pts(26%) were aged < 51 at diagnosis. Of these, 45(17.9%), 145(57.8%), 58(23%), 3(1.2) had G1, G2, G3 and unknown G resp. 208pts(82.9%) had RS ≤ 25, 39pts(15.5%) had RS > 25 and 4pts(1.6%) unknown RS. In the RS ≤ 25 group, 111pts(44%) had RS 0-15, 59(23.5%) had RS16-20, and 38(15.1%) had RS21-25. Post RS testing 595pts(61.8%) had a change in CT decision; 586 changed to hormone therapy (HT) alone, and 9 from HT to CT. In total, 227pts(23.5%) received CT, and 3pts(0.3%) declined. Of pts treated with CT; 9(4%) had RS 0-15, 89(39.2%) had RS16-25, 129(56.8%) had RS > 25. The most common CT regimen was docetaxel and cyclophosphamide(TC), administered to 121pts(53%). RS assay use achieved a 69% change in treatment decision among G2/3 pts and a net 61% reduction in CT use. This resulted in savings of over €4 million in treatment costs. Deducting the assay cost, net savings of over one million euro was achieved. Conclusions: Ireland was the first public healthcare system to approve reimbursement for RS testing. Over the 8 year period of the study, a net 61% reduction in CT use in Irish pts with HR+ ESBC was achieved with conservative net savings of over €1,000,000.

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.