Citations

Abstract Genomic classification has improved risk assignment of pediatric, but not adult B-lineage acute lymphoblastic leukemia (B-ALL). The international UKALLXII/ECOG-ACRIN E2993 (#NCT00002514) trial accrued 1229 adolescent/adult patients with BCR-ABL1− B-ALL (aged 14 to 65 years). Although 93% of patients achieved remission, 41% relapsed at a median of 13 months (range, 28 days to 12 years). Five-year overall survival (OS) was 42% (95% confidence interval, 39, 44). Transcriptome sequencing, gene expression profiling, cytogenetics, and fusion polymerase chain reaction enabled genomic subtyping of 282 patient samples, of which 264 were eligible for trial, accounting for 64.5% of E2993 patients. Among patients with outcome data, 29.5% with favorable outcomes (5-year OS 65% to 80%) were deemed standard risk (DUX4-rearranged [9.2%], ETV6-RUNX1/-like [2.3%], TCF3-PBX1 [6.9%], PAX5 P80R [4.1%], high-hyperdiploid [6.9%]); 50.2% had high-risk genotypes with 5-year OS of 0% to 27% (Ph-like [21.2%], KMT2A-AFF1 [12%], low-hypodiploid/near-haploid [14.3%], BCL2/MYC-rearranged [2.8%]); 20.3% had intermediate-risk genotypes with 5-year OS of 33% to 45% (PAX5alt [12.4%], ZNF384/-like [5.1%], MEF2D-rearranged [2.8%]). IKZF1 alterations occurred in 86% of Ph-like, and TP53 mutations in patients who were low-hypodiploid (54%) and BCL2/MYC-rearranged (33%) but were not independently associated with outcome. Of patients considered high risk based on presenting age and white blood cell count, 40% harbored subtype-defining genetic alterations associated with standard- or intermediate-risk outcomes. We identified distinct immunophenotypic features for DUX4-rearranged, PAX5 P80R, ZNF384-R/-like, and Ph-like genotypes. These data in a large adult B-ALL cohort treated with a non–risk-adapted approach on a single trial show the prognostic importance of genomic analyses, which may translate into future therapeutic benefits.

Microsatellite instability (MSI) is a hallmark of genetic predisposition to DNA damage. It arises from either germline or somatic events leading to impaired function of the mismatch repair system. It can be detected via genetic sequencing or immunohistochemistry with relatively high concordance rates. The presence of MSI in a tumor reflects a high neoantigen load and predicts favorable treatment response to immune checkpoint inhibitors (ICIs). In gastrointestinal cancers, MSI is a predictive biomarker for ICIs with potential prognostic impact but its clinical utility varies widely depending on tumor type. This may be explained by the complexity of tumor microenvironment as highlighted by recent translational studies. In this review, we will discuss the predictive and prognostic value of MSI status in non-colorectal cancers of the digestive system, important clinical trials involving ICIs and potential strategies to overcome resistance to immunotherapy.

402 Background: Pancreas cancer is an aggressive malignancy with limited therapeutic options. Nanoliposomal irinotecan (Nal-IRI) is a preferred second-line treatment, and current guidelines recommend its use in the absence of prior irinotecan. This study aimed to assess whether patients who had received regular irinotecan derive benefit from Nal-IRI. Methods: Medical records of metastatic pancreas cancer patients who had received regular irinotecan and then Nal-IRI were reviewed. The following information was extracted from each medical record: patient demographics, confirmation of a diagnosis of exocrine pancreas cancer, initial cancer stage, dates of administration of the drugs of interest, adverse events that occurred with Nal-IRI treatment, reasons for stopping regular irinotecan, and reasons for starting and stopping Nal-IRI. The primary endpoint was overall survival after the initiation of Nal-IRI (an a priori threshold of > 4 months defined success). Survival data were censored based on date of last follow up. Direct quotes from the medical record were documented to provide insight on prescribing Nal-IRI when guidelines advised the contrary. Results: Sixty four patients met eligibility criteria with a median age of 65 years (range: 36, 80 years). Prior to Nal-IRI, 61 patients had received FOLFIRINOX, and 3 FOLFIRI. Of these, 32 patients manifested progressive disease on regular irinotecan-based therapy. Nal-IRI was prescribed with a fluoropyrimidine; only one patient received monotherapy. At time of analysis, 54 patients had died. Median overall survival from initiation of Nal-IRI was 5.1 months (95% confidence interval (CI): 5.6, 4.3, months). An exploratory comparison, based on no cancer progression with regular irinotecan versus progression, showed improved survival with Nal-IRI in the former group: 6.1 months (95% CI: 9.3, 5.1 months) versus 4.3 months (95% CI: 4.8, 2.3 months); p=0.0006. Nal-IRI adverse events occurred as expected. Qualitative data illustrated several themes, including “limited treatment options,” which appeared to drive the decision to prescribe Nal-IRI. Conclusions: Nal-IRI might be considered in pancreas cancer patients who had received regular irinotecan, particularly in the absence of disease progression with the latter.

10 Background: In colon cancer, tumor deposits (TD) have been associated with worse prognosis, but they are included in the TNM staging system only in the absence of lymph node metastasis (i.e., stage III pN1c tumors). Here we aimed at evaluating the prognostic value of TD and the impact of the addition of TD in the count of lymph node metastases in patients with stage III colon cancer from the CALGB/SWOG 80702 phase III trial (NCT01150045). Methods: Pathological reports of all patients were reviewed for the presence and the count of TD, primary tumor sidedness, lymphovascular invasion and perineural invasion. Cases without available pathological report or without specific information of TD were excluded. Prognostic associations were evaluated by multi-variable Cox models adjusting for treatment arm, T-stage, N-stage, lymphovascular invasion, perineural invasion and lymph node ratio. Results: Overall, 2028 patients were included, with 524 (26%) TD-positive and 1504 (74%) TD-negative stage III tumors. Of the TD-positive patients, 80 (15.4%) were node negative (i.e., pN1c), 239 (46.1%) were pN1a/b and 200 (38.55%) were pN2. 17.2% and 37.0% of all pN1a/b and pN2 tumors had TD. Overall median follow-up was 69.3 months. The presence of TD was associated with poorer DFS (adjusted hazard ratio (aHR) = 1.59, 95%CI 1.28-1.91) and OS (aHR = 1.52, 95%CI 1.18-1.95) in the overall population. The negative effect of TD on DFS and OS was observed for both pN1a/b and pN2 groups and confirmed in multivariate Cox model. Among TD-positive patients, the number of TD had a linear negative effect on DFS and OS. Adding TD to the count of lymph node metastases, 104 of 1570 (6.6%) patients initially considered as pN1 were re-staged as pN2. Re-staged pN2 patients experienced worse DFS (3-year DFS rate: 65.5% versus 80.3%, P = .0003) and OS (5-year OS rate: 69.1 versus 87.8%, P = .0005) than patients confirmed as pN1. Re-staged pN2 patients had similar DFS than patients initially staged as pN2 (3-year DFS rate: 65.5% versus 63.1%, P = .1992). OS curves of these 2 groups crossed, with better outcomes during the first 3 years of follow-up but poorer 5-year estimates for re-staged pN2 patients (5-year OS rate: 69.1% versus 74.8%, P = .0436). Conclusions: TD are found in more than one fourth of stage III colon cancer specimens. The number of TD has a linear deleterious effect on patients’ prognosis. Adding the number of TD to the count of lymph node metastases improves the prognostication accuracy of the TNM staging. Support: U10CA180821, U10CA180882; https://acknowledgments.alliancefound.org . Clinical trial information: NCT01150045.

Colorectal cancer (CRC) is the third most commonly diagnosed cancer worldwide. Universal MMR/MSI testing is standard of care for all patients with newly diagnosed CRC based on multi-society guidelines in the United States. Such testing is intended to identify patients with Lynch Syndrome due to a germline mutation in an MMR gene, but also detects those with sporadic dMMR/MSI-high CRCs. The prognostic utility of MMR/MSI status in non-metastatic colorectal cancer has been studied extensively, yet more limited data are available for its predictive utility. Results have not been entirely consistent due to potential stage-related differences and limited numbers of dMMR/MSI-H patients included in the studies. In this review, we summarize the current evidence for the prognostic and predictive value of dMMR/MSI-H in non-metastatic CRC, and discuss the use of this biomarker for patient management and treatment decisions in clinical practice.

Abstract Tumor mutational burden (TMB), defined as the number of somatic mutations per megabase of interrogated genomic sequence, varies across malignancies. Panel sequencing–based estimates of TMB have largely replaced whole-exome sequencing–derived TMB in the clinic. Retrospective evidence suggests that TMB can predict the efficacy of immune checkpoint inhibitors, and data from KEYNOTE-158 led to the recent FDA approval of pembrolizumab for the TMB-high tumor subgroup. Unmet needs include prospective validation of TMB cutoffs in relationship to tumor type and patient outcomes. Furthermore, standardization and harmonization of TMB measurement across test platforms are important to the successful implementation of TMB in clinical practice. Significance: Evaluation of TMB as a predictive biomarker creates the need to harmonize panel-based TMB estimation and standardize its reporting. TMB can improve the predictive accuracy for immunotherapy outcomes, and has the potential to expand the candidate pool of patients for treatment with immune checkpoint inhibitors.

Abstract Background: Persons of African ancestry (AA) experience a 1.5-2-fold risk of multiple myeloma (MM) compared to persons of European ancestry (EA). We assembled a set of MM patients with self-reported AA in order to evaluate the contribution of genetics to etiology in this high-risk group. Methods: Here we present the results of a meta-analysis of two GWAS in 1,813 cases and 8,871 controls of AA. We also conducted an admixture mapping scan to identify risk alleles associated with local ancestry, fine-mapped the 23 known susceptibility loci to find markers that could better capture MM risk in individuals of AA, and constructed a polygenic risk score (PRS) to assess the aggregated effect of known MM risk alleles. Finally, we conducted an eQTL analysis measuring gene expression in those genes harboring a risk variant in malignant plasma cells from 292 of the patients from a single site. Results: In GWAS analysis, we identified two suggestive novel loci located at 9p24.3 and 9p13.1 at P<1 × 10-6, but no genome-wide significant association was noted. In admixture mapping, we observed a genome-wide significant inverse association between local AA at 2p24.1-23.1 and MM risk in AA individuals. 20 of the 23 known EA risk variants showed directional consistency and 9 replicated at P<0.05 in AA individuals. In eight regions, we identified markers that better capture MM risk in persons of AA. AA individuals with a PRS in the top 10% had a 1.82-fold (95%CI: 1.56, 2.11) increased MM risk compared to those with average risk (25-75%). The strongest functional association was between the risk allele for variant rs56219066 at 5q15 and lower ELL2 expression (P= 5.1 × 10–12). Conclusion: Our study shows that common genetic variation contributes to MM risk individuals of AA. This abstract is also being presented as Poster C040. Citation Format: Zhaohui Du, Niels Weinhold, Gregory Chi Song, Kristen A. Rand, David J. Van Den Berg, Amie E. Hwang, Xin Sheng, Victor Hom, Sikander Ailawadhi, Ajay K. Nooka, Seema Singhal, Karen Pawlish, Edward Peters, Cathryn Bock, Ann Mohrbacher, Alexander Stram, Sonja I. Berndt, William J. Blot, Graham Casey, Victoria L. Stevens, Rick Kittles, Phyllis J. Goodman, W. Ryan Diver, Anselm Hennis, Barbara Nemesure, Eric A. Klein, Benjamin A. Rybicki, Janet L. Stanford, John S. Witte, Lisa Signorello, Esther M. John, Leslie Bernstein, Antoinette Stroup, Owen W. Stephens, Maurizio Zangari, Frits Van Rhee, Andrew Olshan, Wei Zheng, Jennifer J. Hu, Regina Ziegler, Sarah J. Nyante, Sue Ann Ingles, Michael Press, John David Carpten, Stephen Chanock, Jayesh Mehta, Graham A Colditz, Jeffrey Wolf, Thomas G. Martin, Michael Tomasson, Mark A. Fiala, Howard Terebelo, Nalini Janakiraman, Laurence Kolonel, Kenneth C. Anderson, Loic Le Marchand, Daniel Auclair, Brian C.-H. Chiu, Elad Ziv, Daniel Stram, Ravi Vij, Leon Bernal-Mizrachi, Gareth J. Morgan, Jeffrey A. Zonder, Carol Ann Huff, Sagar Lonial, Robert Z. Orlowski, David V. Conti, Christopher A. Haiman, Wendy Cozen. A meta-analysis of genome-wide association study and eQTL analysis of multiple myeloma among African Americans [abstract]. In: Proceedings of the Twelfth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2019 Sep 20-23; San Francisco, CA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(6 Suppl_2):Abstract nr PR05.

4099 Background: Colorectal cancer (CRC) incidence and mortality has decreased since the 1970s but the incidence is increasing in young adults (age 20-49). The incidence of early onset CRC (eoCRC) will keep increasing significantly based on the trends of the SEER CRC registry data. There is limited data suggesting eoCRC may have different behaviors compared to traditional CRC (tCRC, age ≥ 50). Methods: Individual pt data of 47184 stage II/III CRC pts from 25 randomized studies in the ACCENT database were pooled. The distributions of demographics, clinicopathological features, biomarker status, and treatment-related data were summarized by age group. Overall survival (OS), disease-free survival (DFS), recurrence-free rate (RFR), and survival after recurrence (SAR) were assessed by Kaplan-Meier curves and Cox models stratified by treatment arms within studies, adjusting for stage, performance status (PS), BMI and grade. Results: Using 5% difference between age groups as clinically meaningful cutoff, eoCRC had similar gender, race, ethnicity, PS, risk group, disease sidedness and T stage as tCRC. eoCRC were less likely overweight (30 vs 36%) and more pts had ≥ 12 lymph nodes resected (63 vs 51%). eoCRC had more frequent dMMR status (18 vs 12%), less BRAF mutations (5 vs 13%), and more dMMR/BRAF wild type (WT) status (17 vs 7%). Overall, eoCRC had better OS, DFS, and SAR, with the most significant differences between the < 30 and > = 70 age groups. Similar results were observed within pMMR pts. eoCRC experienced less hematological side effects, diarrhea, and stomatitis, but had more nausea and/or vomiting. Conclusions: eoCRC have unique characteristics; although statistically significant, the clinical differences in outcomes between eoCRC and tCRC are potentially due to the difference seen in extremely young and old pts. eoCRC have a different adverse events panel compared to tCRC. [Table: see text]

e11051 Background: Limited data exist on patient (pt) experience and work productivity (WP) in MBC. VIRGO is a prospective OCS following >1200 pts with locally advanced or MBC receiving 1st-line hormonal therapy (HT) or chemotherapy (CT) in a real-world setting. We report baseline characteristics of 277 pts from the VIRGO PRO substudy and correlations between health-related quality of life (HRQoL), symptoms, activities of daily living, and WP. Methods: Symptom severity and interference (MD Anderson Symptom Inventory [MDASI]), functional status (Activity Level Scale [ALS] from the Rotterdam Symptom Checklist) and WP (Work Productivity and Activity Impairment Questionnaire) were assessed. Pts rated their HRQoL during the past week on a scale of 0–10. Results: See table. The five most severe symptoms at baseline were fatigue, decreased sexual interest, disturbed sleep, drowsiness, and emotional distress; these were reported with less severity in the HT cohort (24%-37% vs 42%-59%). Overall MDASI severity and interference correlated with WP measures in the CT (R = 0.46 to 0.78) and HT cohorts (0.36 to 0.94). Mean of the five most severe symptoms also significantly correlated with WP indices (R = 0.47 to 0.66). HRQoL correlated (p < 0.05) with all WP measures (R = -0.46 to -0.56) in the CT cohort and with % impairment while working (R = -0.65) and % overall work impairment (R = -0.71) in the HT cohort. In univariate regression analysis, MDASI symptom interference score was the best predictor of reduced WP (R2 = 0.52 while working; R2 = 0.48 for nonwork activities). Conclusions: MBC pts receiving CT and HT report significant work impairment. Results indicate moderate correlations between WP indices, HRQoL and symptom burden. [Table: see text]