Neoadjuvant trastuzumab deruxtecan (T-DXd) with response-directed definitive therapy in early stage HER2-positive breast cancer: a phase II study protocol (SHAMROCK study).

BACKGROUND: The current standard of care in the neoadjuvant setting for high-risk HER2-positive (HER2 +) breast cancer is to combine systemic chemotherapy with dual HER2 blockade, trastuzumab and pertuzumab. Targeted therapies have significantly improved outcomes for patients with HER2-positive breast cancer. To improve treatment-associated toxicity, chemotherapy-sparing approaches are currently being investigated. Trastuzumab deruxtecan (T-DXd) is an HER2-directed antibody-drug-conjugate (ADC) with promising results in the metastatic setting for HER2-positive breast cancer. The SHAMROCK study investigates neoadjuvant T-DXd in early stage HER2-positive breast cancer, using pathological complete response (pCR) rate as the primary endpoint. METHODS: This is a phase II open-label, single arm, adaptive multi-centre trial of T-DXd in the neoadjuvant setting in stage 2-3 HER2-positive breast cancer. Eligible patients will receive 5.4 mg/kg of T-DXd intravenously every 3 weeks for up to 6 cycles. A repeat biopsy will performed after 2 cycles for the RNA disruption index (RDI) score assessment. According to their likelihood of pCR, as determined by the RDI score, patients will either undergo 4 or 6 cycles of T-DXd prior to imaging. Patients with imaging complete response (iCR) after either 4 or 6 cycles will proceed to surgery. Patients who do not achieve iCR will either undergo further systemic therapy or proceed to surgery. DISCUSSION: The SHAMROCK study is a chemotherapy-sparing approach to curative intent treatment, investigating neoadjuvant T-DXd. We hypothesise that neoadjuvant T-DXd will have a high pCR rate and be associated low toxicity in early stage HER2-positive breast cancer. TRIAL REGISTRATION: EudraCT Number: 2022-002485-32; ClinicalTrials.gov identifier: NCT05710666; Cancer Trials Ireland study number: CTRIAL-IE 22-01.

Pregnancy-associated breast cancer: evaluating maternal and foetal outcomes. A national study.

PURPOSE: Pregnancy-associated breast cancer (PABC) is defined as breast cancer diagnosed during the gestational period (gp-PABC) or in the first postpartum year (pp-PABC). Despite its infrequent occurrence, the incidence of PABC appears to be rising due to the increasing propensity for women to delay childbirth. We have established the first retrospective registry study of PABC in Ireland to examine specific clinicopathological characteristics, treatments, and maternal and foetal outcomes. METHODS: This was a national, multi-site, retrospective observational study, including PABC patients treated in 12 oncology institutions from August 2001 to January 2020. Data extracted included information on patient demographics, tumour biology, staging, treatments, and maternal/foetal outcomes. Survival data for an age-matched breast cancer population over a similar time period was obtained from the National Cancer Registry of Ireland (NCRI). Standard biostatistical methods were used for analyses. RESULTS: We identified 155 patients-71 (46%) were gp-PABC and 84 (54%) were pp-PABC. The median age was 36 years. Forty-four patients (28%) presented with Stage III disease and 25 (16%) had metastatic disease at diagnosis. High rates of triple-negative (25%) and HER2+ (30%) breast cancer were observed. We observed an inferior 5-year overall survival (OS) rate in our PABC cohort compared to an age-matched breast cancer population in both Stage I-III (77.6% vs 90.9%) and Stage IV disease (18% vs 38.3%). There was a low rate (3%) of foetal complications. CONCLUSION: PABC patients may have poorer survival outcomes. Further prospective data are needed to optimise management of these patients.

Optimal management of gastroesophageal junction cancer.

Although recent decades have witnessed incremental improvements in the treatment of gastroesophageal junction (GEJ) carcinoma, outcomes remain modest. For locally advanced esophageal cancer, the addition of chemotherapy and/or radiation to surgery is considered the standard of care. Chemotherapy remains the primary treatment for metastatic disease and improves survival over best supportive care. However, the prognosis for patients with GEJ cancers, which are treated along the same paradigms as esophageal and gastric carcinomas, remain poor because of the emergence of chemoresistance and limited targeted therapeutic approaches, which include agents that target the HER2 and vascular endothelial growth factor pathways. Evaluation of immune checkpoint inhibitors in the chemorefractory setting have confirmed the activity of immunotherapy in esophagogastric cancer. Ongoing immunotherapeutic strategies are being evaluated in both the locally advanced and metastatic settings. This review focuses on the treatment of locally advanced and metastatic GEJ carcinomas, which encompass all tumors that have an epicenter within 5 cm proximal or distal to the anatomical Z-line (Siewert classification). Because the vast majority of GEJ tumors are adenocarcinoma, the management of adenocarcinoma is the focus of this review. Evolving approaches and areas of clinical equipoise are discussed.

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.

Perioperative versus total neoadjuvant chemotherapy in gastric cancer.

Background: Perioperative chemotherapy is standard of care management for locally advanced gastric cancer (GC), but a substantial proportion of patients do not complete adjuvant therapy due to postoperative complications and prolonged recovery. Administration of all chemotherapy prior to surgery in the form of total neoadjuvant therapy (TNT) may optimize complete delivery of systemic therapy. Methods: We performed a retrospective review of GC patients who had surgery at Memorial Sloan Kettering Cancer Center (MSKCC) from May 2014 to June 2020. Results: One hundred and forty-nine patients were identified; 121 patients received perioperative chemotherapy and 28 patients received TNT. TNT was chosen if patients had interim radiographic and/or clinical response to treatment. Baseline characteristics were well-balanced between the two group except for chemotherapy regimen; more TNT patients received FLOT compared to the perioperative group (79% vs. 31%). There was no difference in the proportion of patients who completed all planned cycles, but TNT patients received a higher proportion of cycles containing all chemotherapy drugs (93% vs. 74%, P<0.001). Twenty-nine patients (24%) in the perioperative group did not receive intended adjuvant therapy. There was no significant difference in hospital length of stay or surgical morbidity. The overall distribution of pathologic stage was similar between the two groups. Fourteen percent of TNT patients and 5.8% of perioperative patients achieved a pathologic complete response (P=0.6). There was no significant difference in recurrence free survival (RFS) or overall survival (OS) between the TNT and perioperative groups [24-month OS rate 77% vs. 85%, HR 1.69 (95% CI: 0.80-3.56)]. Conclusions: Our study was limited by a small TNT sample size and biases inherent to a retrospective analysis. TNT appears to be feasible in a select population, without any increase in surgical morbidity.

Consensus statement on the surveillance of patients with gastrointestinal malignancies.

BACKGROUND: Improvements in early detection, screening and treatment of cancer have resulted in a significant improvement in cancer mortality and an increase in the number of cancer survivors globally. Accordingly, a significant rise in the number of cancer survivors in Ireland has been observed. The surveillance of survivors of gastrointestinal malignancies in Ireland is heterogeneous and represents an unmet need for standardisation. AIMS: There are currently no national guidelines in Ireland to guide follow-up practices for these patients. The aim of this study was to establish homogeneity nationally with respect to follow-up of these patients by medical oncologists. METHODS/RESULTS: A consensus group consisting of Irish oncologists with an interest in gastrointestinal malignancies was created to address this issue, and determined that it would be reasonable to adopt the NCCN guidelines for this purpose, but that this recommendation would not be prescriptive, and should be individualised to each patient. CONCLUSION: We hope that this initiative may help to homogenise survivorship practices in this cohort of Irish patients, and may support the implementation of survivorship initiatives by the National Cancer Control Programme (NCCP).

Phase I/Ib study of crenolanib with ramucirumab and paclitaxel as second-line therapy for advanced esophagogastric adenocarcinoma.

PURPOSE: Paclitaxel plus ramucirumab is a standard second-line regimen for patients with advanced gastric adenocarcinoma, but clinical benefit remains modest. One potential resistance mechanism to VEGFR2 inhibition is activation of the PDGF/PDGFR pathway, which can be blocked by the selective inhibitor crenolanib. Therefore, we performed a phase I/Ib study of crenolanib in combination with paclitaxel/ramucirumab. METHODS: Patients with metastatic esophagogastric adenocarcinoma refractory to first-line therapy received escalating doses of crenolanib [60 mg twice daily (BID) to 100 mg three times daily (TID)] in combination with paclitaxel 80 mg/m2 intravenously on days 1, 8 and 15 and ramucirumab 8 mg/kg intravenously on days 1 and 15 of a 28-day cycle. The primary objective was to determine the maximally tolerated dose (MTD) of crenolanib. Additional patients were enrolled in the dose expansion cohort to assess 6-month progression-free survival (PFS) at the MTD. RESULTS: We enrolled 19 patients in the dose escalation phase and 8 patients in the dose expansion phase at the MTD of crenolanib 100 mg BID. Common grade 3/4 treatment-emergent adverse events included leukopenia (19%), anemia (11%) and neutropenia (11%). In the 14 patients treated at the MTD, 6-month PFS was 43% [95% confidence interval (CI) 23-78%] and the objective response rate (ORR) was 42% (95% CI 15-72%). The trial was terminated early due to withdrawal of crenolanib by the sponsor. CONCLUSIONS: The addition of crenolanib to paclitaxel/ramucirumab is safe and well-tolerated at a dose level up to 100 mg BID. CLINICAL TRIAL REGISTRATION: NCT03193918. June 19, 2017.

Can 18F-FDG PET/CT Radiomics Features Predict Clinical Outcomes in Patients with Locally Advanced Esophageal Squamous Cell Carcinoma?

This study aimed to assess the usefulness of radiomics features of 18F-FDG PET/CT in patients with locally advanced esophageal cancers (ESCC) in predicting outcomes such as clinical tumor (cT) and nodal (cN) categories, PET response to induction chemotherapy (PET response), progression-free survival (PFS), and overall survival (OS). Pretreatment PET/CT images from patients who underwent concurrent chemoradiotherapy from July 2002 to February 2017 were segmented, and data were split into training and test sets. Model development was performed on the training datasets and a maximum of five features were selected. Final diagnostic accuracies were determined using the test dataset. A total of 86 PET/CTs (58 men and 28 women, mean age 65 years) were segmented. Due to small lesion size, 12 patients were excluded. The diagnostic accuracies as derived from the CT, PET, and combined PET/CT test datasets were as follows: cT category-70.4%, 70.4%, and 81.5%, respectively; cN category-69.0%, 86.2%, and 86.2%, respectively; PET response-60.0%, 66.7%, and 70.0%, respectively; PFS-60.7%, 75.0%, and 75.0%, respectively; and OS-51.7%, 55.2%, and 62.1%, respectively. A radiomics assessment of locally advanced ESCC has the potential to predict various clinical outcomes. External validation of these models would be further helpful.

Metastatic medullary thyroid carcinoma presenting as ectopic Cushing's syndrome.

SUMMARY: A 41-year-old male presented to the Emergency Department with a 6-month history of back and hip pain. Skeletal survey revealed bilateral pubic rami fractures and MRI of the spine demonstrated multiple thoracic and lumbar fractures. Secondary work up for osteoporosis was undertaken. There was no evidence of hyperparathyroidism and the patient was vitamin D replete. Testosterone (T) was low at 1.7 nmol/L (8.6-29.0) and gonadotrophins were undetectable. The patient failed a 1 mg dexamethasone suppression test (DST) with a morning cortisol of 570 nmol/L (<50) and subsequently a low dose DST with a cortisol post 48 h of dexamethasone of 773 nmol/L (<50) and an elevated ACTH 98 ng/L. A corticotropin-releasing factor (CRF) test suggested ectopic ACTH secretion. The patient was commenced on teriparatide for osteoporosis and metyrapone to control the hypercortisolaemia. A positron emission tomography (PET) scan to look for the source of ACTH secretion demonstrated right neck adenopathy. Biopsy and subsequent lymph node dissection were performed and histology revealed a metastatic neuroendocrine tumour. Immunostaining was positive for calcitonin and thyroid transcription factor 1 (TTF1). Serum calcitonin was also significantly elevated at 45 264 ng/L (<10). The patient proceeded to a total thyroidectomy and left neck dissection. Histology confirmed a 7 mm medullary thyroid carcinoma (MTC). Post-operatively, the patient commenced vandetanib therapy and achieved a clinical and biochemical response. After approximately 18 months of vandetanib therapy, the patient developed recurrent disease in his neck. He is currently on LOXO-292 and is doing well 36 months post-diagnosis. LEARNING POINTS: Unexplained osteoporosis requires thorough investigation and the workup for secondary causes is not complete without excluding glucocorticoid excess. MTC should be considered when searching for sources of ectopic ACTH secretion. Resistance to tyrosine kinase inhibitors is well described with MTC and clinicians should have a low threshold for screening for recurrent disease.

Virtual oncology clinics during the COVID-19 pandemic.

BACKGROUND: The COVID-19 pandemic has resulted in radical changes in the delivery of healthcare worldwide. Our oncology service (at an Irish national cancer centre) rapidly transitioned to the use of telemedicine or virtual clinics (VC) to minimise potential risk of exposure to COVID-19 amongst an immunosuppressed, high-risk population. Our study aimed to evaluate the use of VC in this setting. METHODS: An 18-point questionnaire was designed to investigate the patient experience of VC during the COVID-19 pandemic in Ireland and compliance with guidelines developed in Ireland to conduct VC and the role of VC in the future. Questionnaires were distributed following the receipt of verbal consent from patients during the VC. Descriptive statistics were utilised for data analysis using SPSS®. RESULTS: One hundred and four patients returned completed surveys (n = 104/164, 63% response rate). Overall satisfaction levels were high with most patients (n = 58/100, 58%; no answer provided (NAP), n = 4) equally satisfied or nearly equally satisfied with VC in comparison to a usual clinic encounter. The majority of patients felt that there should be a role for VC in the future (n = 84/102, 82%; NAP, n = 2). The majority of patients (n = 61/99, 61%; NAP, n = 5) were very relieved to avoid a hospital visit due to perceived risk of potential exposure to COVID-19. CONCLUSION: The majority of oncology patients were satisfied with a VC encounter. VC may have a role in the future of medical care in Ireland post the COVID-19 pandemic.

Genomic profiling of a dedifferentiated mucosal melanoma following exposure to immunotherapy.

The treatment landscape for metastatic melanoma has been revolutionised by the introduction of immunotherapy and targeted therapies. Despite these advances, some patients exhibit primary or acquired resistance to treatment. We present the case of a resected mucosal melanoma that on relapse underwent transformation to a dedifferentiated state. The relapsed tumour was phenotypically disparate and demonstrated loss of all typical melanoma-associated immunohistochemical markers. Furthermore, it demonstrated aggressive biological behaviour and immunotherapy resistance. We performed genomic profiling of the original and relapsed tumour to further elucidate the mechanisms underlying this rare phenomenon. Mass spectrometry-based single-nucleotide polymorphism genotyping technology was used to screen for mutations in the original and recurrent tumour. Whole-exome sequencing was performed on the original tumour, recurrent tumour and blood. Both the original and recurrent tumour shared a NRAS mutation, a similar aneuploidy profile and proportion of somatic single-nucleotide variants. However, in contrast to the original tumour, the recurrent tumour demonstrated a lower mutational burden and deletions in the CDKN2A/CDKN2B and CHEK2 genes. The genomic similarity between the original and recurrent tumour attests to a common ancestry and the possible existence of nongenomic drivers inciting phenotype plasticity. In contrast, the low mutational load and potential inactivation of tumour suppressor genes in the recurrent tumour may underlie its rapid proliferative rate and immunoresistance. Dynamic treatment models are desired in the future to track the genomic and epigenetic evolution of a tumour to guide optimal therapy choice and sequencing.

Single-institution experience with selective internal radiation therapy (SIRT) for the treatment of unresectable colorectal liver metastases.

BACKGROUND: Liver metastases are the commonest cause of death for patients with colorectal cancer. Growing evidence supports the use of selective internal radiation therapy (SIRT) in combination with conventional chemotherapy regimens for liver-only or liver-dominant unresectable metastatic colorectal cancer. AIMS: To measure and evaluate outcomes of the first 20 consecutive patients with unresectable colorectal liver metastasis selected for SIRT in addition to their chemotherapy at a single Irish institution. METHODS: Retrospective case series was performed. Patient charts and medical records were reviewed. RESULTS: All 20 patients (100%) selected for angiographic workup were subsequently successfully treated with radioembolization. All patients were discharged 1 day post-SIRT. At initial imaging evaluation, 12 (60%) had a partial response in their liver, 2 (10%) had stable disease, and 6 (30%) had liver-specific progressive disease. Median follow up was 10 months (range 6-26). At last follow up, 14 (70%) patients were alive and 6 (30%) deceased. Most recent imaging demonstrated 2 (10%) with a complete response, 7 (35%) had a partial response, 2 (10%) had stable disease, and 9 (45%) had progressive disease within their liver. One patient was downstaged to hepatic resection, and one with a complete hepatic response had his primary sigmoid tumor resected 11 months post-SIRT. CONCLUSIONS: SIRT is a safe and effective therapy for certain patients with unresectable colorectal liver metastases. This case series supports our opinion that selected patients should be offered SIRT in concert with their medical oncologist, concomitant with their chemotherapy. Larger multi-center studies are required to more clearly define the patient groups that will derive most benefit from SIRT.

Maximizing response: a case report of salvage chemotherapy after immune checkpoint inhibition in a patient with previous chemo-refractory metastatic esophageal carcinoma.

Esophageal carcinoma is an aggressive malignancy and outcomes remain poor. Immune checkpoint inhibitors are a standard-of-care in the third-line and beyond settings, although benefit is modest. Herein, we report the case of a patient who achieved a partial response to salvage chemotherapy following treatment with an immune checkpoint inhibitor despite having chemo-refractory disease. A 41-year-old male, with a history of Crohn's disease, was diagnosed with Her2-positive metastatic esophageal adenocarcinoma to lungs and lymph nodes. The patient received multiple lines of systemic therapy including: first-line modified DCF (docetaxel/cisplatin/5-fluorouracil) with trastuzumab, second-line trastuzumab/afatinib on a clinical study, third-line carboplatin/irinotecan/ramucirumab and fourth-line treatment with a Her2 antibody-drug conjugate, DS-8201A, on a phase I study. While the patient was not a candidate for clinical trials evaluating immune checkpoint inhibitors due to his history of Crohn's disease, the latter was well controlled. Thus, the patient commenced pembrolizumab as fifth-line of treatment 2 years since diagnosis. After 3 cycles of therapy, the patient developed grade 3 immune-related colitis and treatment was discontinued. The patient maintained a good performance status and commenced a sixth-line of carboplatin/irinotecan/ramucirumab. Subsequent imaging demonstrated a partial response which was maintained over a 6-month period. This case demonstrates a response to previously administered chemotherapy following immune checkpoint inhibitor therapy, despite prior progression on this chemotherapy regimen. To our knowledge, this has not been previously reported in esophagogastric carcinoma (EGC). Post-immune checkpoint inhibitor chemotherapy may be a feasible treatment strategy. Research is needed to evaluate the role of post-immune checkpoint inhibitor chemotherapy in patients with metastatic EGC.

Where youth matters-clinicopathologic characteristics and emerging trends in treatment and outcomes in young Irish women with breast cancer.

BACKGROUND: Young women with breast cancer (YWBC) represent 7-12% of breast cancer diagnoses and ostensibly have more biologically aggressive subtypes with higher relapse and mortality rates. We studied the clinical and pathological characteristics in YWBC and examined how outcomes and treatment have evolved. METHODS: YWBC were identified from pathology databases at two tertiary centers. Patients were divided into two cohorts: those diagnosed from 2000 to 2005 (C1) and from 2006 to 2015 (C2). Data were retrieved from clinical, radiology, and histology databases. Statistical analysis was performed using R® (V3.2.0). RESULTS: We identified 345 patients. Median age was 36 years (23-39 years). Mastectomy was performed in 232 patients (67.2%) and axillary lymph node clearance (ALNC) in 207 patients (60% [C1 82.7 vs. C2: 49.4%, p < 0.001]). One hundred-seventy patients (49%) were ER + HER2-, 88 (25.5%) were HER2+, and 58 (16.8%) were triple negative. Eighty patients (23.2%) received neoadjuvant therapy. Pathological complete response rates were statistically similar between C1 and C2 [C1 1 (0.9%) vs C2 16 (6.8%) p = 0.1]. Distant relapse occurred in 59 (19%) patients. There was a higher relapse rate (RR) in C1 [27 (32.1%) vs. 32 (15.7%), p < 0.002). HER2+ and ER+ HER2- patients in C1 had higher RRs than C2. Median overall survival in patients with metastatic disease was 29 months (range 2-119 months). CONCLUSION: Locally advanced disease was more prevalent in YWBC. Mastectomy and ALNC rates were high and most received multimodal treatment. The extent of axillary surgery declined over time. Outcomes were unchanged in triple negative patients. These remain a priority for research.

Positron-Emission Tomography Scan-Directed Chemoradiation for Esophageal Squamous Cell Carcinoma: No Benefit for a Change in Chemotherapy in Positron-Emission Tomography Nonresponders.

INTRODUCTION: Preoperative or definitive chemoradiation is an accepted treatment for locally advanced esophageal squamous cell carcinoma (ESCC). The MUNICON study showed that positron-emission tomography (PET) response following induction chemotherapy was predictive of outcomes in patients with gastroesophageal junction adenocarcinoma. We evaluated the predictive value of PET following induction chemotherapy in ESCC patients and assessed the impact of changing chemotherapy during radiation in PET nonresponders. METHODS: We retrospectively reviewed all patients with locally advanced ESCC who received induction chemotherapy and chemoradiation; all patients had a PET before and after induction chemotherapy. Survival was calculated from date of repeat PET using Kaplan-Meier analysis and compared between groups using the log-rank test. RESULTS: Of 111 patients, 70 (63%) were PET responders (defined as a 35% or more decrease in maximum standard uptake value) to induction chemotherapy. PET responders received the same chemotherapy during radiation. Of 41 PET nonresponders, 16 continued with the same chemotherapy and 25 were changed to alternative chemotherapy with radiation. Median progression-free survival (70.1 months versus 7.1 months, p < 0.01) and overall survival (84.8 months versus 17.2 months, p < 0.01) were improved for PET responders versus nonresponders. Median progression-free survival and overall survival for PET nonresponders who changed chemotherapy versus those who did not were 6.4 months versus 8.3 months (p = 0.556) and 14.1 versus 17.2 months (p = 0.81), respectively. CONCLUSIONS: PET after induction chemotherapy highly predicts for outcomes in ESCC patients who receive chemoradiation. However, our results suggest that PET nonresponders do not benefit from changing chemotherapy during radiation. Future trials should use PET nonresponse after induction chemotherapy to identify poor prognosis patients for novel therapies.

Clinical and Molecular Predictors of Response to Immune Checkpoint Inhibitors in Patients with Advanced Esophagogastric Cancer.

PURPOSE: Immune checkpoint inhibitors (ICI) are effective in only a minority of patients with esophagogastric cancer (EGC). Here, we aimed to identify predictors of durable clinical benefit to ICI in EGC. EXPERIMENTAL DESIGN: Patients with advanced EGC treated with ICIs at Memorial Sloan Kettering Cancer Center (New York, NY) were identified. Clinicopathologic variables were assessed. In patients profiled by MSK-IMPACT-targeted sequencing, outcomes were correlated with tumor genomic features. RESULTS: One-hundred sixty-one patients were treated with ICIs (110 with anti-PD-1/PD-L1 antibodies and 51 with anti-CTLA-4 and PD-1/PD-L1 antibodies). The median progression-free survival (PFS) and overall survival (OS) were 1.7 and 4.9 months, respectively. Greater number of disease sites (≥3), liver metastases, treatment with ≥3 prior therapies and ECOG performance status ≥2 were associated with poorer PFS and OS. Patients treated with combination ICI and those with PD-L1-positive tumors had improved outcomes. There was no difference in outcomes between patients treated with antibiotics during or in the 2 months preceding ICI treatment versus those who were not. Occurrence of irAEs was associated with improved OS. In genomically profiled tumors (n = 89), survival was associated with increasing tumor mutation burden (TMB). However, in multivariable analyses and when microsatellite unstable (MSI) patients were excluded, a significant association was no longer observed. CONCLUSIONS: In patients with advanced EGC, heavily pretreated patients, those with high-volume disease and/or poor PS were less likely to benefit from ICI. irAEs were associated with improved OS. TMB correlated with improved survival, but this association was not observed when MSI-high patients were excluded.

HER2: An emerging target in colorectal cancer.

Despite advances in the treatment of metastatic colorectal cancer (CRC) the 5-year survival of patients with this disease remains low. A small proportion of CRCs overexpress the HER2 oncogene and the effective targeting of this pathway in other malignancies such as breast and gastric cancer has led to efforts to determine if it can also be exploited as a target in CRC. Activation of the HER2 pathway as a bypass signalling pathway has been identified as a mechanism of resistance for antiepidermal growth factor receptor antibody therapy in both the first line and salvage settings. It has also been shown that RAS and BRAF wild type metastatic CRC enriches for the presence of HER2 amplification. This knowledge, in addition to preclinical data providing a rationale for dual anti-HER2 targeted therapy has led to several clinical trials. To date, recently published and presented early phase data provide promising evidence suggesting anti-HER2 therapy may have a potentially beneficial role in the treatment of HER2-positive metastatic CRC. Namely, the HERACLES-A and MyPathway studies have shown benefit in a small number of patients with the use of combination trastuzumab-lapatinib and trastuzumab-pertuzumab, respectively. However, data from larger clinical trials are required before HER2-directed therapy is incorporated into standard treatment paradigms for CRC. This review presents an overview of epidermal growth factor receptor and HER2 pathways in CRC and discusses preclinical and clinical studies carried out in this field to date. There is potential that with continued evolution of data in this area, HER2 may become a validated therapeutic target and thus, anti-HER2 therapy may become an additional treatment option for a small population of patients with metastatic CRC.

Comparing Clinical Characteristics and Outcomes of Young-onset and Late-onset Colorectal Cancer: An International Collaborative Study.

BACKGROUND: Compared with the general population, the incidence of young-onset (YO) colorectal cancer (CRC) is increasing. However, a significant knowledge gap exists in the clinical characteristics, treatment patterns, and outcomes for these patients. MATERIALS AND METHODS: Six international tertiary cancer centers conducted a retrospective study. Patients with YO CRC (aged 18-44 years) and LO CRC (aged > 44 years) diagnosed with histologically proven colorectal adenocarcinoma from June 2003 to June 2014 were enrolled. Patients were randomly chosen from each center's database, and the patient demographics and treatment information were collected. The data were then centralized, and the final analysis was performed at a single institution. Cox proportional hazards models were used to estimate the crude and adjusted hazard ratios (HRs) with 95% confidence intervals (CIs) for progression-free survival and mortality, and YO was compared with LO. Site-specific HRs were pooled using a random-effects meta-analysis. RESULTS: Overall, 498 patients, including 224 with YO (129 men; mean age, 37 ± 5.5 years) and 274 with LO (167 men; mean age, 64.8 ± 9.5 years) CRC, were included. At the diagnosis, 137 patients (61.2%) and 122 patients (44.5%) with YO and LO CRC had metastatic disease, respectively. For both cohorts, the 3 most common presenting symptoms were pain, hematochezia, and weight loss. Surgery was performed in 141 YO (63.0%) and 219 LO (79.9%) patients. The longitudinal noncurative treatment patterns were similar, but more biologic therapy was used for these YO patients. The pooled progression-free survival analysis results for first-line noncurative treatment favored LO (HR, 1.96; 95% CI, 1.04-3.68). The mortality analysis showed no significant differences between the 2 groups (YO: HR, 1.53; 95% CI, 0.91-2.58). CONCLUSION: Despite similar treatment patterns and survival outcomes, YO disease might be clinically more aggressive.