Colon Cancer, Version 3.2024, NCCN Clinical Practice Guidelines in Oncology.

Colorectal cancer (CRC) is the fourth most frequently diagnosed cancer and the second leading cause of cancer death in the United States. Management of disseminated metastatic CRC involves various active drugs, either in combination or as single agents. The choice of therapy is based on consideration of the goals of therapy, the type and timing of prior therapy, the mutational profile of the tumor, and the differing toxicity profiles of the constituent drugs. This manuscript summarizes the data supporting the systemic therapy options recommended for metastatic CRC in the NCCN Guidelines for Colon Cancer.

Phase I/II sequencing study of azacitidine, epacadostat, and pembrolizumab in advanced solid tumors.

BACKGROUND: Indoleamine 2,3-dioxygenase 1 (IDO1), an interferon-inducible enzyme, contributes to tumor immune intolerance. Immune checkpoint inhibition may increase interferon levels; combining IDO1 inhibition with immune checkpoint blockade represents an attractive strategy. Epigenetic agents trigger interferon responses and may serve as an immunotherapy priming method. We evaluated whether epigenetic therapy plus IDO1 inhibition and immune checkpoint blockade confers clinical benefit to patients with advanced solid tumors. METHODS: ECHO-206 was a Phase I/II study where treatment-experienced patients with advanced solid tumors (N = 70) received azacitidine plus an immunotherapy doublet (epacadostat [IDO1 inhibitor] and pembrolizumab). Sequencing of treatment was also assessed. Primary endpoints were safety/tolerability (Phase I), maximum tolerated dose (MTD) or pharmacologically active dose (PAD; Phase I), and investigator-assessed objective response rate (ORR; Phase II). RESULTS: In Phase I, no dose-limiting toxicities were reported, the MTD was not reached; a PAD was not determined. ORR was 5.7%, with four partial responses. The most common treatment-related adverse events (AEs) were fatigue (42.9%) and nausea (42.9%). Twelve (17.1%) patients experienced ≥1 fatal AE, one of which (asthenia) was treatment-related. CONCLUSIONS: Although the azacitidine-epacadostat-pembrolizumab regimen was well tolerated, it was not associated with substantial clinical response in patients with advanced solid tumors previously exposed to immunotherapy.

Saccharomyces cerevisiae Ecm2 Modulates the Catalytic Steps of pre-mRNA Splicing.

Genetic, biochemical, and structural studies have elucidated the molecular basis for spliceosome catalysis. Splicing is RNA catalyzed and the essential snRNA and protein factors are well-conserved. However, little is known about how non-essential components of the spliceosome contribute to the reaction and modulate the activities of the fundamental core machinery. Ecm2 is a non-essential yeast splicing factor that is a member of the Prp19-related complex of proteins. Cryo-electron microscopy (cryo-EM) structures have revealed that Ecm2 binds the U6 snRNA and is entangled with Cwc2, a factor previously found to promote a catalytically active conformation of the spliceosome. These structures also indicate that Ecm2 and the U2 snRNA likely form a transient interaction during 5' splice site (SS) cleavage. We have characterized genetic interactions between ECM2 and alleles of splicing factors that alter the catalytic steps in splicing. In addition, we have studied how loss of ECM2 impacts splicing of pre-mRNAs containing non-consensus or competing SS. Our results show that ECM2 functions during the catalytic stages of splicing. Our data are consistent with Ecm2 facilitating the formation and stabilization of the 1st-step catalytic site, promoting 2nd-step catalysis, and permiting alternate 5' SS usage. We propose that Cwc2 and Ecm2 can each fine-tune the spliceosome active site in unique ways. Their interaction network may act as a conduit through which splicing of certain pre-mRNAs, such as those containing weak or alternate splice sites, can be regulated.

Anal Carcinoma, Version 2.2023, NCCN Clinical Practice Guidelines in Oncology.

This discussion summarizes the NCCN Clinical Practice Guidelines for managing squamous cell anal carcinoma, which represents the most common histologic form of the disease. A multidisciplinary approach including physicians from gastroenterology, medical oncology, surgical oncology, radiation oncology, and radiology is necessary. Primary treatment of perianal cancer and anal canal cancer are similar and include chemoradiation in most cases. Follow-up clinical evaluations are recommended for all patients with anal carcinoma because additional curative-intent treatment is possible. Biopsy-proven evidence of locally recurrent or persistent disease after primary treatment may require surgical treatment. Systemic therapy is generally recommended for extrapelvic metastatic disease. Recent updates to the NCCN Guidelines for Anal Carcinoma include staging classification updates based on the 9th edition of the AJCC Staging System and updates to the systemic therapy recommendations based on new data that better define optimal treatment of patients with metastatic anal carcinoma.

Niraparib plus nivolumab or niraparib plus ipilimumab in patients with platinum-sensitive advanced pancreatic cancer: a randomised, phase 1b/2 trial.

BACKGROUND: Establishing alternatives to lifelong chemotherapy for patients with advanced pancreatic cancer has been proposed to address chemotherapy resistance and cumulative toxicity. Poly(ADP-ribose) polymerase (PARP) inhibitors have shown efficacy in this setting, and concurrent immune checkpoint blockade could offer synergistic tumour control. The aim of this study was to test the safety and antitumour activity of maintenance with PARP inhibition combined with immune checkpoint blockade in patients with advanced pancreatic cancer who had a stable response to platinum-based chemotherapy. METHODS: We conducted an open-label, randomised, phase 1b/2 study of niraparib plus anti-PD-1 (nivolumab) or anti-CTLA-4 (ipilimumab) therapy for patients with advanced pancreatic cancer whose cancer had not progressed after at least 16 weeks of platinum-based therapy. Patients were randomly assigned (1:1) via permuted block randomisation (block sizes 2 and 4) to niraparib 200 mg orally per day plus either nivolumab 240 mg intravenously every 2 weeks (later changed to 480 mg intravenously every 4 weeks based on manufacturer update) or ipilimumab 3 mg/kg intravenously every 4 weeks for four doses. The primary endpoints were safety and progression-free survival at 6 months. Treatment groups were not compared for activity, which was assessed in each group against a clinically meaningful progression-free survival at 6 months of 44% (null hypothesis). Superiority of a treatment regimen could be declared if 6-month progression-free survival was 60%, and inferiority if 6-month progression-free survival was 27%. All patients who received at least one dose of study treatment and had at least one post-treatment assessment of response according to Response Evaluation Criteria in Solid Tumours version 1.1 were included in the efficacy population. The safety population consisted of all patients who received at least one dose of study treatment. This study is registered with ClinicalTrials.gov, NCT03404960, and enrolment is completed and follow-up is ongoing. FINDINGS: 91 patients were enrolled between Feb 7, 2018, and Oct 5, 2021 and were randomly assigned to niraparib plus nivolumab (n=46) or niraparib plus ipilimumab (n=45). Of these patients, 84 were evaluable for the progression-free survival endpoint (niraparib plus nivolumab=44; niraparib plus ipilimumab=40). Median follow-up was 23·0 months (IQR 15·0-31·5). 6-month progression-free survival was 20·6% (95% CI 8·3-32·9; p=0·0002 vs the null hypothesis of 44%) in the niraparib plus nivolumab group; and 59·6% (44·3-74·9; p=0·045) in the niraparib plus ipilimumab group. Ten (22%) of 46 patients in the niraparib plus nivolumab group and 23 (50%) of 45 patients in the niraparib plus ipilimumab group had a grade 3 or worse treatment-related adverse event. The most common grade 3 or worse adverse events in the niraparib plus nivolumab group were hypertension (in four [8%] patients), anaemia (two [4%]), and thrombocytopenia (two [4%]) whereas in the niraparib plus ipilimumab group these were fatigue (in six [14%]), anaemia (five [11%]), and hypertension (four [9%]). There were no treatment-related deaths. INTERPRETATION: The primary endpoint of 6-month progression-free survival was met in the niraparib plus ipilimumab maintenance group, whereas niraparib plus nivolumab yielded inferior progression-free survival. These findings highlight the potential for non-cytotoxic maintenance therapies in patients with advanced pancreatic cancer. FUNDING: Bristol Myers Squibb, GlaxoSmithKline, the Basser Center Young Leadership Council, The Konner Foundation, The Pearl and Philip Basser Innovation Research Award, the Anonymous Foundation, and the US National Institutes of Health.

Phase I Trial of Regorafenib, Hydroxychloroquine, and Entinostat in Metastatic Colorectal Cancer.

BACKGROUND: The antiangiogenic tyrosine kinase inhibitor regorafenib provides a survival benefit in patients with previously treated metastatic colorectal cancer (CRC). Antiangiogenic therapy causes hypoxic stress within tumor cells, which activates autophagy as a survival mechanism. The histone deacetylase inhibitor (HDAC) entinostat increases dependence on autophagy through epigenetic mechanisms. Hydroxychloroquine (HCQ) blocks autophagy by blunting lysosomal acidification. We hypothesized that HCQ and entinostat would be tolerable with regorafenib and potentiate the antitumor response. METHODS: This was a 3+3 phase I trial of HCQ and entinostat with regorafenib in patients with metastatic CRC. The primary objective was safety, and the secondary objective was clinical efficacy. RESULTS: Twenty patients received study therapy. Six evaluable patients were enrolled at each of the three planned dose levels, one patient at an intermediate dose level, and one additional patient withdrew consent after 4 days to receive treatment closer to home. One dose-limiting toxicity was noted in the study at dose level 2 (grade 3 fatigue). Seven patients discontinued therapy due to related toxicities; rapid weight loss was near universal, with a median weight loss of 4.4 kg (range 1.5-12.2 kg) in the first 2 weeks of treatment. No objective responses were observed. CONCLUSION: The combination of regorafenib, HCQ, and entinostat was poorly tolerated without evident activity in metastatic CRC. CLINICALTRIALS.GOV IDENTIFIER: NCT03215264.

Rectal Cancer, Version 2.2022, NCCN Clinical Practice Guidelines in Oncology.

This selection from the NCCN Guidelines for Rectal Cancer focuses on management of malignant polyps and resectable nonmetastatic rectal cancer because important updates have been made to these guidelines. These recent updates include redrawing the algorithms for stage II and III disease to reflect new data supporting the increasingly prominent role of total neoadjuvant therapy, expanded recommendations for short-course radiation therapy techniques, and new recommendations for a "watch-and-wait" nonoperative management technique for patients with cancer that shows a complete response to neoadjuvant therapy. The complete version of the NCCN Guidelines for Rectal Cancer, available online at NCCN.org, covers additional topics including risk assessment, pathology and staging, management of metastatic disease, posttreatment surveillance, treatment of recurrent disease, and survivorship.

Colon Cancer, Version 2.2021, NCCN Clinical Practice Guidelines in Oncology.

This selection from the NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines) for Colon Cancer focuses on systemic therapy options for the treatment of metastatic colorectal cancer (mCRC), because important updates have recently been made to this section. These updates include recommendations for first-line use of checkpoint inhibitors for mCRC, that is deficient mismatch repair/microsatellite instability-high, recommendations related to the use of biosimilars, and expanded recommendations for biomarker testing. The systemic therapy recommendations now include targeted therapy options for patients with mCRC that is HER2-amplified, or BRAF V600E mutation-positive. Treatment and management of nonmetastatic or resectable/ablatable metastatic disease are discussed in the complete version of the NCCN Guidelines for Colon Cancer available at NCCN.org. Additional topics covered in the complete version include risk assessment, staging, pathology, posttreatment surveillance, and survivorship.

Value of Precision Medicine in Advanced Non-Small Cell Lung Cancer: Real-World Outcomes Associated with the Use of Companion Diagnostics.

BACKGROUND: Companion diagnostic (CDx) testing for patients with advanced non-small cell lung cancer (aNSCLC) identifies patients more likely to benefit from biomarker-driven treatments. METHODS: Patients with nonsquamous cell (non-Sq) aNSCLC from the Flatiron Health database (diagnosed January 1, 2011-May 31, 2018) who had CDx testing were compared with those who had no reported evidence of testing. The association between CDx testing and overall survival was evaluated by unadjusted and adjusted Cox proportional hazards regression models. Logistic regression analysis identified characteristics associated with CDx testing. The revised modified Lung Cancer Prognostic Index and other factors identified a priori were included in the adjusted models. RESULTS: A total of 17,555 patients with non-Sq aNSCLC (CDx, n = 14,732; no CDx, n = 2,823) with mean ± SD age of 67.2 ± 10.0 years were included. Most were insured (91.7%) and white (67.1%). Asian patients and those who were never-smokers were more likely to undergo CDx testing. Those with CDx testing lived longer than those without (median [95% confidence interval (CI)] survival, 13.04 [12.62-13.40] vs. 6.01 [5.72-6.24] months) and had a decreased mortality risk (adjusted hazard ratio [95% CI], 0.72 [0.69-0.76]). A survival advantage was also seen for patients with CDx testing who received biomarker-driven first-line therapy. CONCLUSION: Patients with non-Sq aNSCLC who had CDx testing had a greater survival benefit than those without, supporting broader use of CDx testing in routine clinical practice to identify patients more likely to benefit from precision medicine. IMPLICATIONS FOR PRACTICE: Companion diagnostic (CDx) testing coupled with biomarker-driven treatment offers a greater survival benefit for patients with advanced non-small cell lung cancer (aNSCLC). In this study, patients with nonsquamous aNSCLC from Flatiron Health, a large, real-world oncology database, with CDx testing had a reduced mortality risk and lived longer than patients without reported evidence of CDx testing; those who received biomarker-driven therapy as their first line of treatment were likely to survive three times longer than those who did not. These results demonstrate the clinical utility of CDx testing as the first step in treating nonsquamous aNSCLC in real-world clinical practice.

NCCN Guidelines Insights: Rectal Cancer, Version 6.2020.

The NCCN Guidelines for Rectal Cancer provide recommendations for the diagnosis, evaluation, treatment, and follow-up of patients with rectal cancer. These NCCN Guidelines Insights summarize the panel discussion behind recent important updates to the guidelines. These updates include clarifying the definition of rectum and differentiating the rectum from the sigmoid colon; the total neoadjuvant therapy approach for localized rectal cancer; and biomarker-targeted therapy for metastatic colorectal cancer, with a focus on new treatment options for patients with BRAF V600E- or HER2 amplification-positive disease.

Efficacy of Oral Cryotherapy During Oxaliplatin Infusion in Preventing Oral Thermal Hyperalgesia: A Randomized Trial.

BACKGROUND: Chemotherapy-induced oral thermal hyperalgesia (OTH) is a common and debilitating side effect of platinum-based anticancer agents. This study evaluated the efficacy of oral cryotherapy in preventing OTH during oxaliplatin chemotherapy infusion. METHODS: Patients with gastrointestinal cancer treated with biweekly oxaliplatin (85 mg/m2 over 120 minutes) at Abramson Cancer Center at the University of Pennsylvania were randomized to receive oral cryotherapy (ice chips) during oxaliplatin infusion or standard-of-care treatment. All patients completed baseline questionnaires regarding oral and peripheral symptoms and on-treatment questionnaires on day 1 of each subsequent chemotherapy cycle. Those in the treatment arm were asked to document how long they kept the ice chips in their mouths (0, <30, 30, 60, 90, or 120 minutes) and to report their discomfort associated with oral cryotherapy. Evaluable patients were those who had completed at least 2 cycles of oxaliplatin therapy. RESULTS: Of 62 randomized patients with a variety of gastrointestinal malignancies, 50 (25 per treatment arm) were evaluable for efficacy. The rate of patients with oral symptoms after the first treatment cycle was significantly lower in the intervention arm (n=8; 32%) than in the control arm (n=18; 72%), meeting the primary study objective (P=.01). The magnitude of difference in symptom scores before versus after the first treatment cycle was significantly less in the intervention versus control arm (P=.001). No difference in oral symptoms over time was seen between the intervention and control groups (P=.20), although a high attrition rate was noted. Duration of ice chip exposure was associated with improved oral symptoms over time (P=.02). CONCLUSIONS: Oral cryotherapy is a tolerable and cost-effective method of diminishing OTH in patients receiving oxaliplatin chemotherapy, and seems to be most effective in the early stages of treatment.

Small Bowel Adenocarcinoma, Version 1.2020, NCCN Clinical Practice Guidelines in Oncology.

Small bowel adenocarcinoma (SBA) is a rare malignancy of the gastrointestinal tract that has increased in incidence across recent years. Often diagnosed at an advanced stage, outcomes for SBA are worse on average than for other related malignancies, including colorectal cancer. Due to the rarity of this disease, few studies have been done to direct optimal treatment, although recent data have shown that SBA responds to treatment differently than colorectal cancer, necessitating a separate approach to treatment. The NCCN Guidelines for Small Bowel Adenocarcinoma were created to establish an evidence-based standard of care for patients with SBA. These guidelines provide recommendations on the workup of suspected SBA, primary treatment options, adjuvant treatment, surveillance, and systemic therapy for metastatic disease. Additionally, principles of imaging and endoscopy, pathologic review, surgery, radiation therapy, and survivorship are described.

Integrated Capecitabine-Temozolomide with Radioembolization for Liver-Dominant G2 NETs: Long-Term Outcomes of a Single-Institution Retrospective Study.

PURPOSE: Capecitabine-Temozolomide (CapTem) is an oral chemotherapy regimen for NETs. Both drugs are radiosensitizers. Integrating CapTem and Y90 transarterial radioembolization (TARE) in patients with grade 2 neuroendocrine tumor (NET) liver metastases achieved an encouraging objective response rate (ORR) and progression-free survival (PFS) in a feasibility study. This study expands that report to a larger cohort with longer follow-up. METHODS: Therapy consisted of monthly cycles of capecitabine 600 mg/m2 twice daily for 14 days and temozolomide 150-200 mg/m2 on day 10-14. Simulation angiography was performed during the initial cycle. The dominant lobe was treated with 90Y-resin microspheres using BSA dosimetry on day 7 of the second cycle of CapTem. Patients with bilobar disease had the other lobe treated on day 7 of the third or fourth cycle. CapTem was continued until progression or intolerance. Clinical and laboratory assessment was done monthly and imaging every 3 months. RESULTS: 35/37 patients completed the prescribed regimen. Primary sites of disease were pancreas (16), lung (10), gut (7) and unknown (4). Mean duration of CapTem was 12 months (range, 4-32 months). ORR in the liver was 72% with a disease control rate of 100%. Median PFS was 36 months (95% CI, 25-45 months). Median overall survival was 41 months (95% CI, 24-87 months) from initiation of CapTemY90 therapy and 130 months (95% CI, 56-172 months) from initial diagnosis. CONCLUSION: Chemoradiation with CapTem and TARE provided durable control of G2 NET liver metastases for substantially longer than expectations for embolotherapy or chemotherapy alone.

A combined histology and transcriptome analysis unravels novel questions on Medicago truncatula seed coat.

The seed coat is involved in the determination of seed quality traits such as seed size, seed composition, seed permeability, and hormonal regulation. Understanding seed coat structure is therefore a prerequisite to deciphering the genetic mechanisms that govern seed coat functions. By combining histological and transcriptomic data analyses, cellular and molecular events occurring during Medicago truncatula seed coat development were dissected in order to relate structure to function and pinpoint target genes potentially involved in seed coat traits controlling final seed quality traits. The analyses revealed the complexity of the seed coat transcriptome, which contains >30 000 genes. In parallel, a set of genes showing a preferential expression in seed coat that may be involved in more specific functions was identified. The study describes how seed coat anatomy and morphological changes affect final seed quality such as seed size, seed composition, seed permeability, and hormonal regulation. Putative regulator genes of different processes have been identified as potential candidates for further functional genomic studies to improve agronomical seed traits. The study also raises new questions concerning the implication of seed coat endopolyploidy in cell expansion and the participation of the seed coat in de novo abscisic acid biosynthesis at early seed filling.

The Clinical Implications of Reversions in Patients with Advanced Pancreatic Cancer and Pathogenic Variants in BRCA1, BRCA2, or PALB2 after Progression on Rucaparib.

PURPOSE: PARP inhibitors (PARPi) provide an effective maintenance option for patients with BRCA- or PALB2-mutated pancreatic cancer. However, mechanisms of PARPi resistance and optimal post-PARPi therapeutic strategies are poorly characterized. EXPERIMENTAL DESIGN: We collected paired cell-free DNA samples and post-PARPi clinical data on 42 patients with advanced, platinum-sensitive pancreatic cancer who were treated with maintenance rucaparib on NCT03140670, of whom 32 developed progressive disease. RESULTS: Peripherally detected, acquired BRCA or PALB2 reversion variants were uncommon (5/30; 16.6%) in patients who progressed on rucaparib. Reversions were significantly associated with rapid resistance to PARPi treatment (median PFS, 3.7 vs. 12.5 months; P = 0.001) and poor overall survival (median OS, 6.2 vs. 23.0 months; P < 0.0001). All patients with reversions received rechallenge with platinum-based chemotherapy following PARPi progression and experienced faster progression on this therapy than those without reversion variants (real-world time-to-treatment discontinuation, 2.4 vs. 5.8 months; P = 0.004). Of the patients who progressed on PARPi and received further chemotherapy, the OS from initiation of second-line therapy was significantly lower in those with reversion variants than in those without (5.5 vs. 12.0 months, P = 0.002). Finally, high levels of tumor shedding were independently associated with poor outcomes in patients who received rucaparib. CONCLUSIONS: Acquired reversion variants were uncommon but detrimental in a population of patients with advanced BRCA- or PALB2-related pancreatic ductal adenocarcinoma who received maintenance rucaparib. Reversion variants led to rapid progression on PARPi, rapid failure of subsequent platinum-based treatment, and poor OS of patients. The identification of such variants in the blood may have both predictive and prognostic value. See related commentary by Tsang and Gallinger, p. 5005.

Head and neck carcinoma in the United States: first comprehensive report of the Longitudinal Oncology Registry of Head and Neck Carcinoma (LORHAN).

BACKGROUND: Detailed information about how patients with head and neck carcinoma (HNC) are treated across practice settings does not exist. The authors conducted a prospective, observational study to examine the patterns of care for a series of patients with newly diagnosed HNC in the United States and to test 2 hypotheses: 1) There is no difference in the pattern of care between community and academic settings; and 2) the results of major randomized clinical trials will change the pattern of care in both practice settings within 1 year of publication in peer-reviewed journals. METHODS: Patients aged ≥ 18 years were enrolled in the Longitudinal Oncology Registry of Head and Neck Carcinoma (LORHAN) after providing written informed consent if they had a confirmed diagnosis of new HNC and were scheduled to receive treatment other than surgery alone. RESULTS: Between 2005 and 2010, 100 centers enrolled 4243 patients, including 2612 patients (62%) from academic investigators and 1631 patients (38%) from community centers. Initial treatments were radiation with concurrent chemotherapy (30%) or cetuximab (9%), adjuvant radiotherapy (21%), induction chemotherapy (16%), and other (24%). Intensity modulated radiation therapy was the dominant radiation technique (84%). Single-agent cisplatin was prescribed in nearly half of patients and more often in academic centers (53% vs 43% of patients; P < .0001). Single-agent cetuximab was the next most common drug used (19%) and was prescribed more frequently in community settings (24% vs 17%; P = .0001). The data rejected the 2 prospective hypotheses. CONCLUSIONS: LORHAN documented differences in patient characteristics and treatments between community and academic settings for a large series of patients in the United States.

Quantifying the impact of the COVID-19 pandemic on gastrointestinal cancer care delivery.

BACKGROUND AND AIM: This study quantifies how changes in healthcare utilization and delivery during the first months of the COVID-19 pandemic have altered the presentation, treatment, and management of patients with gastrointestinal (GI) malignancies within an academic health system. METHODS AND RESULTS: Patients diagnosed with a GI malignancy (ICD10: C15-C26) who received medical care within the health system during the observation period (first 44 weeks of 2019 and 2020) were identified for a retrospective cohort study. Deidentified patient encounter parameters were collected for this observation period and separated into pre-pandemic (weeks 1-10) and early pandemic (weeks 11-20) study periods. Difference-in-difference analyses adjusted for week-specific and year-specific effects quantified the impact of the COVID-19 pandemic on care delivery between pre-pandemic and early pandemic study periods in 2020. Across all GI malignancies, the COVID-19 pandemic has been associated with a significant decline in the number of patients with new patient visits (NPVs) (p = 1.2 × 10-4 ), Radiology encounters (p = 1.9 × 10-7 ), Surgery encounters (p = 1.6 × 10-3 ), Radiation Oncology encounters (p = 4.1 × 10-3 ), and infusion visits (6.1 × 10-5 ). Subgroup analyses revealed cancer-specific variations in changes to delivery. Patients with colorectal cancer (CRC) had the most significant decrease in NPVs (p = 7.1 × 10-5 ), which was significantly associated with a concomitant decrease in colonoscopies performed during the early pandemic period (r2  = 0.722, p = 2.1 × 10-10 ). CONCLUSIONS: The COVID-19 pandemic has been associated with significant disruptions to care delivery. While these effects were appreciated broadly across GI malignancies, CRC, diagnosed and managed by periodic screening, has been affected most acutely.

Predictive risk-score model for selection of patients with high-risk stage II colon cancer for adjuvant systemic therapy.

BACKGROUND: Adjuvant systemic therapy is selectively considered for high-risk stage II colon cancer, but which patients benefit most from adjuvant systemic therapy is unclear. METHODS: Patients who underwent resection of stage II colon cancer were identified from the National Cancer Database (2010-2016). Risk-factors for decreased overall survival on multivariable analysis were used to establish a predictive risk-score model for all-cause mortality. After propensity matching within each risk group, 5-year overall survival was estimated based on receipt of adjuvant systemic therapy. RESULTS: Of the 15,241 patients evaluated, 2,857 (18.8%) received adjuvant systemic therapy. Risk factors for decreased overall survival included age >75 (hazard ratio 3.3, P < .001), male sex (hazard ratio 1.2, P < .001), White/Black race (hazard ratio 1.4, P = .020), preoperative carcinoembryonic antigen >3.5 ng/mL (hazard ratio 1.6, P < .001), T4a T-stage (hazard ratio 2.0, P < .001), T4b T-stage (hazard ratio 2.4, P < .001), lymphovascular invasion (hazard ratio 1.2, P = .003), perineural invasion (hazard ratio 1.3, P = .003), and non-R0 proximal/distal resection margins (hazard ratio 1.7, P < .001). An internally validated risk-score model using these factors was developed composed of low-risk (n = 8,489), moderate-risk (n = 4,623), and high-risk (n = 2,129) groups; within each group, 19.9%, 15.7%, and 20.8% of patients, respectively, received adjuvant systemic therapy. After propensity matching, adjuvant systemic therapy was not associated with improved 5-year overall survival for low-risk patients (89.8% vs 88.3%, P = .280), but was for moderate-risk (80.5% vs 70.8%, P < .001), and high-risk (65.2% vs 45.7%, P < .001) patients. CONCLUSION: A predictive risk-score model incorporating patient and tumor factors identifies a high-risk cohort of stage II colon cancer patients who may benefit from adjuvant systemic therapy, although the minority of these patients appear to be receiving treatment.

Multianalyte Prognostic Signature Including Circulating Tumor DNA and Circulating Tumor Cells in Patients With Advanced Pancreatic Adenocarcinoma.

PURPOSE: Pancreatic ductal adenocarcinoma (PDAC) is associated with a poor prognosis. Multianalyte signatures, including liquid biopsy and traditional clinical variables, have shown promise for improving prognostication in other solid tumors but have not yet been rigorously assessed for PDAC. MATERIALS AND METHODS: We performed a prospective cohort study of patients with newly diagnosed locally advanced pancreatic cancer (LAPC) or metastatic PDAC (mPDAC) who were planned to undergo systemic therapy. We collected peripheral blood before systemic therapy and assessed circulating tumor cells (CTCs), cell-free DNA concentration (cfDNA), and circulating tumor KRAS (ctKRAS)-variant allele fraction (VAF). Association of variables with overall survival (OS) was assessed in univariate and multivariate survival analysis, and comparisons were made between models containing liquid biopsy variables combined with traditional clinical prognostic variables versus models containing traditional clinical prognostic variables alone. RESULTS: One hundred four patients, 40 with LAPC and 64 with mPDAC, were enrolled. CTCs, cfDNA concentration, and ctKRAS VAF were all significantly higher in patients with mPDAC than patients with LAPC. ctKRAS VAF (cube root; 0.05 unit increments; hazard ratio, 1.11; 95% CI, 1.03 to 1.21; P = .01), and CTCs ≥ 1/mL (hazard ratio, 2.22; 95% CI, 1.34 to 3.69; P = .002) were significantly associated with worse OS in multivariate analysis while cfDNA concentration was not. A model selected by backward selection containing traditional clinical variables plus liquid biopsy variables had better discrimination of OS compared with a model containing traditional clinical variables alone (optimism-corrected Harrell's C-statistic 0.725 v 0.681). CONCLUSION: A multianalyte prognostic signature containing CTCs, ctKRAS, and cfDNA concentration outperformed a model containing traditional clinical variables alone suggesting that CTCs, ctKRAS, and cfDNA provide prognostic information complementary to traditional clinical variables in advanced PDAC.

ctDNA Clearance and Radiographic Resolution of Disease in Response to Dual Checkpoint Inhibition in Metastatic Microsatellite Stable Colorectal Cancer with a High Tumor Mutation Burden.

Immunotherapy (IO) has increasingly been demonstrated to provide therapeutic benefit to patients with metastatic colorectal cancer (mCRC). However, only a subset of mCRC tumors respond to IO. Monitoring response with tumor biomarkers like carcinoembryonic antigen (CEA) has been challenging in patients with microsatellite stable (MSS) mCRC due to low expression of CEA (CEA/lo). Noninvasive blood-based biomarkers such as circulating tumor DNA (ctDNA) can inform early treatment response and augment radiographic monitoring. We describe a case study of a patient with chemotherapy-refractory CEA/lo MSS mCRC, with metastatic disease present in a cardiophrenic lymph node. The patient was given 2 cycles of combination IO (ipilimumab/nivolumab). Response was monitored by ctDNA using a multiplex PCR next-generation sequencing assay, CEA, and CT scan. After IO administration, ctDNA levels rapidly declined, becoming undetectable. This was concurrent with radiographic resolution of the lymph node metastasis. Serial monitoring of CEA during this same period was uninformative, with no significant changes observed. Significant decline in ctDNA identified metastatic response to IO in a patient with CEA/lo, MSS mCRC and was concurrently validated by CT scan. This case study provides evidence that ctDNA can be used as a prospective surrogate for radiographic tumor response.