Hypofractionated Radiotherapy-Related Lymphopenia Is Associated With Worse Survival in Unresectable Intrahepatic Cholangiocarcinoma.

OBJECTIVE: The aim of this study was to evaluate the incidence of radiotherapy (RT)-related lymphopenia, its predictors, and association with survival in unresectable intrahepatic cholangiocarcinoma (ICC) treated with hypofractionated-RT (HF-RT). METHODS: Retrospective analysis of 96 patients with unresectable ICC who underwent HF-RT (median 58.05 Gy in 15 fractions) between 2009 and 2022 was performed. Absolute lymphocyte count (ALC) nadir within 12 weeks of RT was analyzed. Primary variable of interest was severe lymphopenia, defined as Grade 3+ (ALC <0.5 k/µL) per CTCAE v5.0. Primary outcome of interest was overall survival (OS) from RT. RESULTS: Median follow-up was 16 months. Fifty-two percent of patients had chemotherapy pre-RT, 23% during RT, and 40% post-RT. Pre-RT, median ALC was 1.1 k/µL and 5% had severe lymphopenia. Post-RT, 68% developed RT-related severe lymphopenia. Patients who developed severe lymphopenia had a significantly lower pre-RT ALC (median 1.1 vs. 1.5 k/µL, P=0.01) and larger target tumor volume (median 125 vs. 62 cm3, P=0.02). In our multivariable Cox model, severe lymphopenia was associated with a 1.7-fold increased risk of death (P=0.04); 1-year OS rates were 63% vs 77% (P=0.03). Receipt of photon versus proton-based RT (OR=3.50, P=0.02), higher mean liver dose (OR=1.19, P<0.01), and longer RT duration (OR=1.49, P=0.02) predicted severe lymphopenia. CONCLUSIONS: HF-RT-related lymphopenia is an independent prognostic factor for survival in patients with unresectable ICC. Patients with lower baseline ALC and larger tumor volume may be at increased risk, and use of proton therapy, minimizing mean liver dose, and avoiding treatment breaks may reduce RT-related lymphopenia.

Patient-Reported Outcomes, Tumor Markers, and Survival Outcomes in Advanced GI Cancer.

Importance: Patient-reported outcomes (PROs), such as quality of life (QOL) and symptoms, are often associated with clinical outcomes in patients with cancer. In practice, oncologists use serum tumor markers (TMs) (ie, carcinoembryonic antigen [CEA] and carbohydrate antigen 19-9 [CA 19-9]) and imaging to monitor clinical outcomes in patients with gastrointestinal cancer. Objective: To examine associations of 1-month changes in PROs and TMs with treatment response and survival among patients with gastrointestinal cancer. Design, Setting, and Participants: This cohort study enrolled patients at Massachusetts General Hospital Cancer Center with at least 1 month follow-up from May 2019 to December 2020. Included patients were beginning first-line systemic therapy, aged 18 years or older, and had been diagnosed with metastatic pancreaticobiliary, colorectal, or gastroesophageal cancer. Data analyses took place from January 2021 to January 2022. Intervention: PROs were collected, including QOL (Functional Assessment of Cancer Therapy General [FACT-G]), physical symptoms (Edmonton Symptom Assessment System [ESAS]), and psychological symptoms (Patient Health Questionnaire-4 [PHQ4] total, PHQ4-depression, and PHQ4-anxiety), as well as TMs (CEA and CA 19-9), at the time of chemotherapy initiation and 1 month later. Main Outcomes and Measures: Associations of 1-month changes in PROs and TMs with treatment response (clinical benefit vs disease progression) at first scan, progression-free survival (PFS), and overall survival (OS), adjusted for baseline values using regression models. Results: This study included 159 patients, with 134 patients (84.3%) evaluable for analysis. Patients had a median (range) age of 64.0 (28.0-84.0) years and 86 (64.2%) were male. One-month PRO changes (FACT-G: OR, 1.07; 95% CI, 1.03-1.11; P = .001; ESAS-total: OR, 0.97; 95% CI, 0.94-1.00; P = .02; ESAS-physical: OR, 0.96; 95% CI, 0.92-1.00; P = .03; PHQ4-depression: OR, 0.67; 95% CI, 0.49-0.92; P = .01) were significantly associated with treatment response, but PHQ4-total or TMs were not. Changes in FACT-G (HR, 0.97; 95% CI, 0.95-0.99; P = .003), ESAS-total (HR, 1.03; 95% CI, 1.01-1.05; P = .004), ESAS-physical (HR, 1.03; 95% CI, 1.00-1.05; P = .02), PHQ4-depression (HR, 1.22; 95% CI, 1.01-1.48; P = .04), and CEA (HR, 1.00; 95% CI, 1.001-1.004; P = .001) were associated with PFS, but changes in PHQ4-total or TMs were not. Changes in ESAS-total (HR, 1.03, 95% CI, 1.01-1.06; P = .006) and ESAS-physical (HR, 1.04, 95% CI, 1.01-1.06; P = .015) were associated with OS, but changes in TMs were not associated with OS. Conclusions and Relevance: These findings suggest that 1-month changes in PROs can be associated with treatment response and survival in patients with advanced gastrointestinal cancer. Notably, 1-month changes in TMs were not consistently associated with these outcomes. These findings highlight the potential for monitoring early changes in PROs to associate with clinical outcomes while underscoring the need to address the QOL and symptom concerns of patients with advanced cancer.

Feasibility, Safety, and Efficacy of Aggressive Multimodal Management of Elderly Patients with Pancreatic Ductal Adenocarcinoma.

OBJECTIVE: We aimed to evaluate the safety and efficacy of NAT followed by surgical resection in patients with PDAC aged ≥75 years. SUMMARY BACKGROUND DATA: Whether administration of neoadjuvant therapy (NAT) followed by surgical resection in elderly patients with pancreatic ductal adenocarcinoma (PDAC) is safe and effective is unknown. METHODS: The present study is a three-part comparison of older (≥ 75 years) versus younger (< 75 years) patients in different settings throughout the continuum of PDAC care. The first analysis was a comparison of older versus younger consecutive patients with non-metastatic PDAC who were initiated on FOLFIRINOX. The second was a comparison of older vs. younger patients who underwent NAT followed by surgical resection, and the third and final analysis was a comparison of older patients who underwent either NAT followed by surgical resection vs. upfront surgical resection. Postoperative complications, overall survival (OS), and time to recurrence (TTR), were compared. Propensity-score matching (PSM) analysis was performed to adjust for potential confounders. RESULTS: In the first analysis, a lower proportion of older patients (n=40) were able to complete the intended neoadjuvant FOLFIRINOX (8) cycles compared to younger patients (n=214) (65.0% vs. 81.4%, P=0.021). However, older patients were just as likely to undergo surgical exploration as younger patients (77.5% vs 78.5%, P=0.89) as well as surgical resection (57.5% vs 55.6%, P=0.70). In the second analysis, PSM was conducted to compare older (n=54) vs. younger patients (n=54) who underwent NAT followed by surgical resection. There were no significant differences in postoperative complications between the matched groups. While there was a significant difference in overall survival (OS) between older and younger patients (median OS: 16.43 months vs. 30.83 months, P=0.002), importantly, there was no significant difference in time to recurrence (TTR, median: 7.65 months vs. 11.83 months, P=0.215). In the third analysis, older patients who underwent NAT followed by surgical resection (n=48) were compared with similar older patients who underwent upfront surgical resection (n=48). After PSM, there was a significant difference in OS (median OS: 15.78 months vs. 11.51 months, P=0.037) as well as TTR (median TTR: 8.81 months vs. 7.10 months, P=0.046) representing an association with improved outcomes that favored the neoadjuvant approach among older patients alone. CONCLUSIONS: This comprehensive three-part study showed that administration of NAT followed by surgical resection appears to be safe and effective among patients ≥ 75 years of age. An aggressive approach should be offered to older adults undergoing multimodal treatment of PDAC.

Portal Vein or Superior Mesenteric Vein Thrombosis with Dose-Escalated Radiation for Borderline or Locally Advanced Pancreatic Cancer.

PURPOSE: Portal vein and superior mesenteric vein thrombosis (PVT/SMVT) are potentially morbid complications of radiation dose-escalated local therapy for pancreatic cancer. We retrospectively reviewed records for patients treated with and without intraoperative radiation (IORT) to identify risk factors for PVT/SMVT. METHODS: Ninety-six patients with locally advanced or borderline resectable pancreatic adenocarcinoma received neoadjuvant therapy followed by surgical exploration from 2009 to 2014. Patients at risk for close or positive surgical margins received IORT boost to a biologically effective dose (BED10) > 100. Prognostic factors for PVT/SMVT were evaluated using competing risks regression. RESULTS: Median follow-up was 79 months for surviving patients. Fifty-six patients (58%) received IORT. Twenty-nine patients (30%) developed PVT/SMVT at a median time of 18 months. On univariate competing risks regression, operative blood loss and venous repair with a vascular interposition graft, but not IORT dose escalation or diabetes history, were significantly associated with PVT/SMVT. The development of thrombosis in the absence of recurrence was significantly associated with a longstanding diabetes history, post-neoadjuvant treatment CA19-9, and operative blood loss. All 4 patients who underwent both IORT and vascular repair with a graft developed PVT/SMVT. PVT/SMVT in the absence of recurrence is not associated with significantly worsened overall survival but led to frequent medical interventions. CONCLUSIONS: Approximately 30% of patients who underwent neoadjuvant chemoradiation for PDAC developed PVT/SMVT a median of 18 months following surgery. This was significantly associated with venous reconstruction with vascular grafts, but not with escalating radiation dose. PVT/SMVT in the absence of recurrence was associated with significant morbidity.

Tolerability, Attrition Rates, and Survival Outcomes of Neoadjuvant FOLFIRINOX for Nonmetastatic Pancreatic Adenocarcinoma: Intent-to-Treat Analysis.

BACKGROUND: FOLFIRINOX is increasingly used in the management of pancreatic ductal adenocarcinoma (PDAC). However, neoadjuvant therapy is associated with toxicity, possible disease progression, and biopsy-related and biliary complications that may preclude operative exploration. Data on the true attrition rate outside of clinical trials or resected surgical series are lacking. STUDY DESIGN: Patients with nonmetastatic PDAC who initiated FOLFIRINOX from 2015 to 2020 were identified from our institution's pharmacy records. Multivariable regression and Cox proportional hazard models were used for adjusted analyses of categorical and survival outcomes, respectively. RESULTS: Of 254 patients who initiated first-line neoadjuvant FOLFIRINOX, 199 (78.3%) underwent exploration, and 54 (21.3%) did not complete their chemotherapy cycles due to poor tolerability (46.3%), poor response (31.5%), or disease progression (14.8%), among other causes (7.4%). A total of 109 (42.9%) patients experienced grade 3/4 FOLFIRINOX-related toxicity, of whom 73 (28.7%) and 100 (39.4%) required an emergency department visit or inpatient admission, respectively. Finally, not undergoing surgical exploration was associated with impaired overall survival (hazard ratio 7.0; 95% CI 3.8 to 12.8; p < 0.001). Independent predictors of not undergoing exploration were remote history of chemotherapy receipt (odds ratio [OR] 0.06; p = 0.02), inability to complete FOLFIRINOX cycles (OR 0.2, p = 0.003), increase in ECOG score (OR 0.2, p < 0.001), and being single or divorced (OR 0.3, p = 0.018). CONCLUSIONS: Among 254 patients with nonmetastatic PDAC initiated on FOLFIRINOX, of whom 52% were locally advanced, a total of 199 (78.3%) were explored, 142 (71.4%) underwent successful resection, and 129 (90.8%) were resected with negative margins. Despite 109 (42.9)% of patients experiencing significant toxicity, most patients could be managed through treatment-related complications to complete planned neoadjuvant chemotherapy and undergo planned surgical exploration.

Combined PD-1, BRAF and MEK inhibition in BRAFV600E colorectal cancer: a phase 2 trial.

While BRAF inhibitor combinations with EGFR and/or MEK inhibitors have improved clinical efficacy in BRAFV600E colorectal cancer (CRC), response rates remain low and lack durability. Preclinical data suggest that BRAF/MAPK pathway inhibition may augment the tumor immune response. We performed a proof-of-concept single-arm phase 2 clinical trial of combined PD-1, BRAF and MEK inhibition with sparatlizumab (PDR001), dabrafenib and trametinib in 37 patients with BRAFV600E CRC. The primary end point was overall response rate, and the secondary end points were progression-free survival, disease control rate, duration of response and overall survival. The study met its primary end point with a confirmed response rate (24.3% in all patients; 25% in microsatellite stable patients) and durability that were favorable relative to historical controls of BRAF-targeted combinations alone. Single-cell RNA sequencing of 23 paired pretreatment and day 15 on-treatment tumor biopsies revealed greater induction of tumor cell-intrinsic immune programs and more complete MAPK inhibition in patients with better clinical outcome. Immune program induction in matched patient-derived organoids correlated with the degree of MAPK inhibition. These data suggest a potential tumor cell-intrinsic mechanism of cooperativity between MAPK inhibition and immune response, warranting further clinical evaluation of optimized targeted and immune combinations in CRC. ClinicalTrials.gov registration: NCT03668431.

A Phase II Study of Ziv-Aflibercept in Patients With Advanced Extrapancreatic Neuroendocrine Tumors.

OBJECTIVES: Neuroendocrine tumors (NETs) are characterized by their expression of vascular endothelial growth factor (VEGF). This trial investigated the activity of Ziv-aflibercept, a recombinant protein that binds to and inhibits the activity of VEGF, in patients with advanced NETs (NCT01782443). METHODS: A single-arm, phase II trial enrolling patients with advanced, progressive extrapancreatic NET. Patients were treated with Ziv-aflibercept 4 mg/kg intravenously on day 1 and 15 of a 28-day cycle; the starting dose was reduced to 2 mg/kg on days 1 and 15 of a 28-day cycle because of hypertension-related events. The primary end point was progression-free survival. RESULTS: The trial enrolled 19 patients (13 male:6 female). Patients received a median of 7 cycles (range, 1-18 cycles). The median progression free survival was 11.8 months (95% confidence interval, 3.2-16.1 months), and the median overall survival was 36.4 months (95% confidence interval, 16.1-not reached). Best responses by Response Evaluation Criteria in Solid Tumors 1.1 are as follows: 1 (5%) partial response, 13 (68%) stable disease, 2 (10%) with progressive disease, and 3 (15%) unevaluable. Hypertension occurred in 18 patients (95%), including grade 3-4 hypertension in 12 patients (63%). CONCLUSIONS: Although the progression free survival is similar to other VEGF inhibitors in NET, toxicity may preclude further investigation.

Supportive Oncology Care at Home Intervention for Patients With Pancreatic Cancer.

PURPOSE: We sought to determine the feasibility of delivering a Supportive Oncology Care at Home intervention among patients with pancreatic cancer. METHODS: We prospectively enrolled patients with pancreatic cancer from a parent trial of neoadjuvant fluorouracil, leucovorin, oxaliplatin, and irinotecan (FOLFIRINOX). The intervention entailed (1) remote monitoring of patient-reported symptoms, vital signs, and body weight; (2) a hospital-at-home care model; and (3) structured communication with the oncology team. We defined the intervention as feasible if ≥ 60% of patients enrolled in the study and ≥ 60% completed the daily assessments within the first 2-weeks of enrollment. We determined rates of treatment delays, urgent clinic visits, emergency department visits, and hospitalizations among those who did (n = 20) and did not (n = 24) receive Supportive Oncology Care at Home from the parent trial. RESULTS: From January 2019 to September 2020, we enrolled 80.8% (21/26) of potentially eligible patients. One patient became ineligible following consent because of moving out of state, resulting in 20 participants (median age = 67 years). In the first 2 weeks of enrollment, 65.0% of participants completed all daily assessments. Overall, patients reported 96.1% of daily symptoms, 96.1% of daily vital signs, and 92.5% of weekly body weights. Patients receiving the intervention had lower rates of treatment delays (55.0% v 75.0%), urgent clinic visits (10.0% v 25.0%), and emergency department visits/hospitalizations (45.0% v 62.5%) compared with those not receiving the intervention from the same parent trial. CONCLUSION: Findings demonstrate the feasibility and acceptability of a Supportive Oncology Care at Home intervention. Future work will investigate the efficacy of this intervention for decreasing health care use and improving patient outcomes.

Reverse Transcriptase Inhibition Disrupts Repeat Element Life Cycle in Colorectal Cancer.

Altered RNA expression of repetitive sequences and retrotransposition are frequently seen in colorectal cancer, implicating a functional importance of repeat activity in cancer progression. We show the nucleoside reverse transcriptase inhibitor 3TC targets activities of these repeat elements in colorectal cancer preclinical models with a preferential effect in p53-mutant cell lines linked with direct binding of p53 to repeat elements. We translate these findings to a human phase II trial of single-agent 3TC treatment in metastatic colorectal cancer with demonstration of clinical benefit in 9 of 32 patients. Analysis of 3TC effects on colorectal cancer tumorspheres demonstrates accumulation of immunogenic RNA:DNA hybrids linked with induction of interferon response genes and DNA damage response. Epigenetic and DNA-damaging agents induce repeat RNAs and have enhanced cytotoxicity with 3TC. These findings identify a vulnerability in colorectal cancer by targeting the viral mimicry of repeat elements. SIGNIFICANCE: Colorectal cancers express abundant repeat elements that have a viral-like life cycle that can be therapeutically targeted with nucleoside reverse transcriptase inhibitors (NRTI) commonly used for viral diseases. NRTIs induce DNA damage and interferon response that provide a new anticancer therapeutic strategy. This article is highlighted in the In This Issue feature, p. 1397.

Neoadjuvant versus Postoperative Chemoradiotherapy is Associated with Improved Survival for Patients with Resectable Gastric and Gastroesophageal Cancer.

BACKGROUND: The optimal timing of chemoradiotherapy (CRT) for patients with localized gastric cancer remains unclear. This study aimed to compare the survival outcomes between neoadjuvant and postoperative CRT for patients with gastric and gastroesophageal junction (GEJ) cancer. METHODS: This retrospective study analyzed 152 patients with gastric (42%) or GEJ (58%) adenocarcinoma who underwent definitive surgical resection and received either neoadjuvant or postoperative CRT between 2005 and 2017 at the authors' institution. The primary end point of the study was overall survival (OS). RESULTS: The median follow-up period was 37.5 months. Neoadjuvant CRT was performed for 102 patients (67%) and postoperative CRT for 50 patients (33%). The patients who received neoadjuvant CRT were more likely to be male and to have a GEJ tumor, positive lymph nodes, and a higher clinical stage. The median radiotherapy (RT) dose was 50.4 Gy for neoadjuvant RT and 45.0 Gy for postoperative RT (p < 0.001). The neoadjuvant CRT group had a pathologic complete response (pCR) rate of 26% and a greater rate of R0 resection than the postoperative CRT group (95% vs. 76%; p = 0.002). Neoadjuvant versus postoperative CRT was associated with a lower rate of any grade 3+ toxicity (10% vs. 54%; p < 0.001). The multivariable analysis of OS showed lower hazards of death to be independently associated neoadjuvant versus postoperative CRT (hazard ratio [HR] 0.57; 95% confidence interval [CI] 0.36-0.91; p = 0.020) and R0 resection (HR 0.50; 95% CI 0.27-0.90; p = 0.021). CONCLUSIONS: Neoadjuvant CRT was associated with a longer OS, a higher rate of R0 resection, and a lower treatment-related toxicity than postoperative CRT. The findings suggest that neoadjuvant CRT is superior to postoperative CRT in the treatment of gastric and GEJ cancer.

Prospective Phase II Trials Validate the Effect of Neoadjuvant Chemotherapy on Pattern of Recurrence in Pancreatic Adenocarcinoma.

OBJECTIVE: The objective of this study was to characterize the patterns of first recurrence after curative-intent resection for pancreatic adenocarcinoma (PDAC). SUMMARY OF BACKGROUND DATA: We evaluated the first site of recurrence after neoadjuvant treatment as locoregional (LR) or distant metastasis (DM). To validate our findings, we evaluated the pattern from 2 phase II clinical trials evaluating neoadjuvant chemotherapy (NAC) in PDAC. METHODS: We identified site of first recurrence from a retrospective cohort of patients from 2011 to 2017 treated with NAC followed by chemoradiation and then an operation or an operation first followed by adjuvant therapy, and 2 separate prospective cohorts of patients derived from 2 phase II clinical trials evaluating patients treated with NAC in borderline-resectable and locally advanced PDAC. RESULTS: In the retrospective cohorts, 160 out of 285 patients (56.1%) recurred after a median disease-free survival (mDFS) of 17.2 months. The pattern of recurrence was DM in 81.9% of patients, versus LR in 11.1%. This pattern was consistent in patients treated with upfront resection and adjuvant chemotherapy (DM 83.0%, LR 16.9%) regardless of margin-involvement (DM 80.1%, LR 19.4%). The use of NAC did not alter pattern of recurrence; 81.7% had DM and 18.3% had LR. This pattern also remained consistent regardless of margin-involvement (DM 94.1%, LR 5.9%). In the Phase II borderline-resectable trial (NCI# 01591733) cohort of 32 patients, the mDFS was 34.2 months. Pattern of recurrence remained predominantly DM (88.9%) versus LR (11.1%). In the Phase II locally-advanced trial (NCI# 01821729) cohort of 34 patients, the mDFS was 30.7 months. Although there was a higher rate of local recurrence in this cohort, pattern of first recurrence remained predominantly DM (66.6%) versus LR (33.3%) and remained consistent independent of margin-status. CONCLUSIONS: The pattern of recurrence in PDAC is predominantly DM rather than LR, and is consistent regardless of the use of NAC and margin involvement.

Response prediction of neoadjuvant chemoradiation therapy in locally advanced rectal cancer using CT-based fractal dimension analysis.

OBJECTIVES: There are individual variations in neo-adjuvant chemoradiation therapy (nCRT) in patients with locally advanced rectal cancer (LARC). No reliable modality currently exists that can predict the efficacy of nCRT. The purpose of this study is to assess if CT-based fractal dimension and filtration-histogram texture analysis can predict therapeutic response to nCRT in patients with LARC. METHODS: In this retrospective study, 215 patients (average age: 57 years (18-87 years)) who received nCRT for LARC between June 2005 and December 2016 and underwent a staging diagnostic portal venous phase CT were identified. The patients were randomly divided into two datasets: a training set (n = 170), and a validation set (n = 45). Tumor heterogeneity was assessed on the CT images using fractal dimension (FD) and filtration-histogram texture analysis. In the training set, the patients with pCR and non-pCR were compared in univariate analysis. Logistic regression analysis was applied to identify the predictive value of efficacy of nCRT and receiver operating characteristic analysis determined optimal cutoff value. Subsequently, the most significant parameter was assessed in the validation set. RESULTS: Out of the 215 patients evaluated, pCR was reached in 20.9% (n = 45/215) patients. In the training set, 7 out of 37 texture parameters showed significant difference comparing between the pCR and non-pCR groups and logistic multivariable regression analysis incorporating clinical and 7 texture parameters showed that only FD was associated with pCR (p = 0.001). The area under the curve of FD was 0.76. In the validation set, we applied FD for predicting pCR and sensitivity, specificity, and accuracy were 60%, 89%, and 82%, respectively. CONCLUSION: FD on pretreatment CT is a promising parameter for predicting pCR to nCRT in patients with LARC and could be used to help make treatment decisions. KEY POINTS: • Fractal dimension analysis on pretreatment CT was associated with response to neo-adjuvant chemoradiation in patients with locally advanced rectal cancer. • Fractal dimension is a promising biomarker for predicting pCR to nCRT and may potentially select patients for individualized therapy.

Results and Molecular Correlates from a Pilot Study of Neoadjuvant Induction FOLFIRINOX Followed by Chemoradiation and Surgery for Gastroesophageal Adenocarcinomas.

PURPOSE: We performed a NCI-sponsored, prospective study of neoadjuvant FOLFIRINOX followed by chemoradiation with carboplatin/paclitaxel followed by surgery in patients with locally advanced gastric or gastroesophageal cancer. PATIENTS AND METHODS: The primary objective was to determine completion rate of neoadjuvant FOLFIRINOX × 8 followed by chemoradiation. Secondary endpoints were toxicity and pathologic complete response (pCR) rate. Exploratory analysis was performed of circulating tumor DNA (ctDNA) to treatment response. RESULTS: From October 2017 to June 2018, 25 patients were enrolled. All patients started FOLFIRINOX, 92% completed all eight planned cycles, and 88% completed chemoradiation. Twenty (80%) patients underwent surgical resection, and 7 had a pCR (35% in resected cohort, 28% intention to treat). Tumor-specific mutations were identified in 21 (84%) patients, of whom 4 and 17 patients had undetectable and detectable ctDNA at baseline, respectively. Presence of detectable post-chemoradiation ctDNA (P = 0.004) and/or postoperative ctDNA (P = 0.045) were associated with disease recurrence. CONCLUSIONS: Here we show neoadjuvant FOLFIRINOX followed by chemoradiation for locally advanced gastroesophageal cancer is feasible and yields a high rate of pCR. ctDNA appears to be a promising predictor of postoperative recurrence.See related commentary by Catenacci, p. 6281.

Care Patterns and Overall Survival in Patients With Early-Onset Metastatic Colorectal Cancer.

PURPOSE: Colorectal cancer (CRC) incidence in patients younger than 50 years of age, commonly defined as early-onset (EO-CRC), is rising. EO-CRC often presents with distinct clinicopathologic features. However, data on prognosis are conflicting and outcomes with modern treatment approaches for metastatic disease are still limited. MATERIALS AND METHODS: We prospectively enrolled patients with metastatic CRC (mCRC) to a biobanking and clinical data collection protocol from 2014 to 2018. We grouped the cohort based on age at initial diagnosis: < 40 years, 40-49 years, and ≥ 50 years. We used regression models to examine associations among age at initial diagnosis, treatments, clinicopathologic features, and survival. RESULTS: We identified 466 patients with mCRC (45 [10%] age < 40 years, 109 [23%] age 40-49 years, and 312 [67%] age ≥ 50 years). Patients < 40 years of age were more likely to have received multiple metastatic resections (odds ratio [OR], 3.533; P = .0066) than their older counterparts. Patients with EO-CRC were more likely to receive triplet therapy than patients > 50 years of age (age < 40 years: OR, 6.738; P = .0002; age 40-49 years: OR, 2.949; P = .0166). Patients 40-49 years of age were more likely to have received anti-EGFR therapy (OR, 2.633; P = .0016). Despite differences in care patterns, age did not predict overall survival. CONCLUSION: Despite patients with EO-CRC receiving more intensive treatments, survival was similar to the older counterpart. However, EO-CRC had clinical and molecular features associated with worse prognoses. Improved biologic understanding is needed to optimize clinical management of EO-CRC. The cost-benefit ratio of exposing patients with EO-CRC to more intensive treatments has to be carefully evaluated.

Minimal Residual Disease Detection using a Plasma-only Circulating Tumor DNA Assay in Patients with Colorectal Cancer.

PURPOSE: Detection of persistent circulating tumor DNA (ctDNA) after curative-intent surgery can identify patients with minimal residual disease (MRD) who will ultimately recur. Most ctDNA MRD assays require tumor sequencing to identify tumor-derived mutations to facilitate ctDNA detection, requiring tumor and blood. We evaluated a plasma-only ctDNA assay integrating genomic and epigenomic cancer signatures to enable tumor-uninformed MRD detection. EXPERIMENTAL DESIGN: A total of 252 prospective serial plasma specimens from 103 patients with colorectal cancer undergoing curative-intent surgery were analyzed and correlated with recurrence. RESULTS: Of 103 patients, 84 [stage I (9.5%), II (23.8%), III (47.6%), IV (19%)] had evaluable plasma drawn after completion of definitive therapy, defined as surgery only (n = 39) or completion of adjuvant therapy (n = 45). In "landmark" plasma drawn 1-month (median, 31.5 days) after definitive therapy and >1 year follow-up, 15 patients had detectable ctDNA, and all 15 recurred [positive predictive value (PPV), 100%; HR, 11.28 (P < 0.0001)]. Of 49 patients without detectable ctDNA at the landmark timepoint, 12 (24.5%) recurred. Landmark recurrence sensitivity and specificity were 55.6% and 100%. Incorporating serial longitudinal and surveillance (drawn within 4 months of recurrence) samples, sensitivity improved to 69% and 91%. Integrating epigenomic signatures increased sensitivity by 25%-36% versus genomic alterations alone. Notably, standard serum carcinoembryonic antigen levels did not predict recurrence [HR, 1.84 (P = 0.18); PPV = 53.9%]. CONCLUSIONS: Plasma-only MRD detection demonstrated favorable sensitivity and specificity for recurrence, comparable with tumor-informed approaches. Integrating analysis of epigenomic and genomic alterations enhanced sensitivity. These findings support the potential clinical utility of plasma-only ctDNA MRD detection.See related commentary by Bent and Kopetz, p. 5449.

Conditional Survival in Resected Pancreatic Ductal Adenocarcinoma Patients Treated with Total Neoadjuvant Therapy.

BACKGROUND: Dynamic survival data based on time already survived are lacking for resected borderline resectable/locally advanced (BR/LA) pancreatic ductal adenocarcinoma (PDAC) patients who received total neoadjuvant therapy (TNT) with FOLFIRINOX followed by chemoradiation. Conditional survival, i.e., the probability of surviving an additional length of time after having already survived an amount of time, offers such information. We aimed to determine actuarial and conditional overall (OS, COS) and disease-free survival (DFS, CDFS) among this cohort. METHODS: Clinicopathologic data were retrospectively collected for resected BR/LA PDAC patients who received TNT (2011-2019). COS and CDFS rates were calculated for patients being event (death/recurrence)-free at multiple intervals and by recurrence status. RESULTS: After a median follow-up of 32.1 months, the 183 patients had a median OS and DFS of 39.1 months and 16.8 months, respectively. COS and CDFS increased as a function of time already survived. The probability of surviving an additional 24 months if a patient survived 2 years post-operatively was 70%, whereas the 4-year actuarial OS was 47%. Similarly, the probability of surviving disease-free an additional 24 months after 2 years was 66%, while actuarial 48-month DFS was 27%. COS for disease-free patients increased further over time. For patients remaining disease-free 12 months post-operatively, BR vs. LA status at diagnosis, tumor ≤ 4 cm at diagnosis, and R0 resection were independent predictors of favorable additional OS and DFS. CONCLUSIONS: For resected TNT-treated BR/LA PDAC patients, the probability of surviving an additional length of time increases as a function of survival already accrued. Dynamic survival estimates may allow personalized follow-up and counseling.

Tumor Microenvironment Immune Response in Pancreatic Ductal Adenocarcinoma Patients Treated With Neoadjuvant Therapy.

BACKGROUND: Neoadjuvant folinic acid, fluorouracil, irinotecan, and oxaliplatin (FOLFIRINOX) and chemoradiation have been used to downstage borderline and locally advanced pancreatic ductal adenocarcinoma (PDAC). Whether neoadjuvant therapy-induced tumor immune response contributes to the improved survival is unknown. Therefore, we evaluated whether neoadjuvant therapy induces an immune response towards PDAC. METHODS: Clinicopathological variables were collected for surgically resected PDACs at the Massachusetts General Hospital (1998-2016). Neoadjuvant regimens included FOLFIRINOX with or without chemoradiation, proton chemoradiation (25 Gy), photon chemoradiation (50.4 Gy), or no neoadjuvant therapy. Human leukocyte antigen (HLA) class I and II expression and immune cell infiltration (CD4+, FoxP3+, CD8+, granzyme B+ cells, and M2 macrophages) were analyzed immunohistochemically and correlated with clinicopathologic variables. The antitumor immune response was compared among neoadjuvant therapy regimens. All statistical tests were 2-sided. RESULTS: Two hundred forty-eight PDAC patients were included. The median age was 64 years and 50.0% were female. HLA-A defects were less frequent in the FOLFIRINOX cohort (P = .006). HLA class II expression was lowest in photon and highest in proton patients (P = .02). The FOLFIRINOX cohort exhibited the densest CD8+ cell infiltration (P < .001). FOLFIRINOX and proton patients had the highest CD4+ and lowest T regulatory (FoxP3+) cell density, respectively. M2 macrophage density was statistically significantly higher in the treatment-naïve group (P < .001) in which dense M2 macrophage infiltration was an independent predictor of poor overall survival. CONCLUSIONS: Neoadjuvant FOLFIRINOX with or without chemoradiation may induce immunologically relevant changes in the tumor microenvironment. It may reduce HLA-A defects, increase CD8+ cell density, and decrease T regulatory cell and M2 macrophage density. Therefore, neoadjuvant FOLFIRINOX therapy may benefit from combinations with checkpoint inhibitors, which can enhance patients' antitumor immune response.

Radiation therapy enhances immunotherapy response in microsatellite stable colorectal and pancreatic adenocarcinoma in a phase II trial.

Overcoming intrinsic resistance to immune checkpoint blockade for microsatellite stable (MSS) colorectal cancer (CRC) and pancreatic ductal adenocarcinoma (PDAC) remains challenging. We conducted a single-arm, non-randomized, phase II trial (NCT03104439) combining radiation, ipilimumab and nivolumab to treat patients with metastatic MSS CRC (n = 40) and PDAC (n = 25) with an Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1. The primary endpoint was disease control rate (DCR) by intention to treat. DCRs were 25% for CRC (ten of 40; 95% confidence interval (CI), 13-41%) and 20% for PDAC (five of 25; 95% CI, 7-41%). In the per-protocol analysis, defined as receipt of radiation, DCR was 37% (ten of 27; 95% CI, 19-58%) in CRC and 29% (five of 17; 95% CI, 10-56%) in PDAC. Pretreatment biopsies revealed low tumor mutational burden for all samples but higher numbers of natural killer (NK) cells and expression of the HERVK repeat RNA in patients with disease control. This study provides proof of concept of combining radiation with immune checkpoint blockade in immunotherapy-resistant cancers.

Associations of baseline patient-reported outcomes with treatment outcomes in advanced gastrointestinal cancer.

BACKGROUND: Patient-reported outcomes (PROs) assessing quality of life (QOL) and symptom burden correlate with clinical outcomes in patients with cancer. However, to the authors' knowledge, data regarding associations between PROs and treatment response are lacking. METHODS: The authors prospectively approached consecutive patients with advanced gastrointestinal cancer who were initiating a new treatment. Prior to treatment, patients reported their QOL (Functional Assessment of Cancer Therapy-General [FACT-G], 4 subscales: Functional, Physical, Emotional, Social; higher scores indicate better QOL) and symptom burden (Edmonton Symptom Assessment System [ESAS], Patient Health Questionnaire-4 [PHQ-4]; higher scores represent greater symptoms). Regression models were used to examine associations of baseline PROs with treatment response (clinical benefit or progressive disease [PD] at time of first scan), healthcare utilization, and survival. RESULTS: From May 2019 to April 2020, a total of 112 patients with advanced gastrointestinal cancer were enrolled. For treatment response, 64.3% had CB and 35.7% had PD. Higher baseline ESAS-Physical (odds ratio, 1.04; P = .027) and lower FACT-G Functional (odds ratio, 0.92; P = .038) scores were associated with PD. Higher ESAS-Physical (hazard ratio [HR], 1.03; P = .044) and lower FACT-G Total (HR, 0.96; P = .005), FACT-G Physical (HR, 0.89; P < .001), and FACT-G Functional (HR, 0.87; P < .001) scores were associated with a greater hospitalization risk. Lower FACT-G Total (HR, 0.96; P = .009) and FACT-G Emotional (HR, 0.86; P = .012) scores as well as higher ESAS-Total (HR, 1.03; P = .014) and ESAS-Physical (HR, 1.04; P = .032) scores were associated with worse survival. CONCLUSIONS: Baseline PROs are associated with treatment response in patients with advanced gastrointestinal cancer, namely physical symptoms and functional QOL, in addition to health care use and survival. The findings of the current study support the association between PROs and important clinical outcomes, including the novel finding of treatment response.

Chemoradiation-Related Lymphopenia and Its Association with Survival in Patients with Squamous Cell Carcinoma of the Anal Canal.

BACKGROUND: Although treatment-related lymphopenia (TRL) is common and associated with poorer survival in multiple solid malignancies, few data exist for anal cancer. We evaluated TRL and its association with survival in patients with anal cancer treated with chemoradiation (CRT). MATERIALS AND METHODS: A retrospective analysis of 140 patients with nonmetastatic anal squamous cell carcinoma (SCC) treated with definitive CRT was performed. Total lymphocyte counts (TLC) at baseline and monthly intervals up to 12 months after initiating CRT were analyzed. Multivariable Cox regression analysis was performed to evaluate the association between overall survival (OS) and TRL, dichotomized by grade (G)4 TRL (<0.2k/µL) 2 months after initiating CRT. Kaplan-Meier and log-rank tests were used to compare OS between patients with versus without G4 TRL. RESULTS: Median time of follow-up was 55 months. Prior to CRT, 95% of patients had a normal TLC (>1k/µL). Two months after initiating CRT, there was a median of 71% reduction in TLC from baseline and 84% of patients had TRL: 11% G1, 31% G2, 34% G3, and 8% G4. On multivariable Cox model, G4 TRL at two months was associated with a 3.7-fold increased risk of death. On log-rank test, the 5-year OS rate was 32% in the cohort with G4 TRL versus 86% in the cohort without G4 TRL. CONCLUSION: TRL is common and may be another prognostic marker of OS in anal cancer patients treated with CRT. The association between TRL and OS suggests an important role of the host immunity in anal cancer outcomes. IMPLICATIONS FOR PRACTICE: This is the first detailed report demonstrating that standard chemoradiation (CRT) commonly results in treatment-related lymphopenia (TRL), which may be associated with a poorer overall survival (OS) in patients with anal squamous cell carcinoma. The association between TRL and worse OS observed in this study supports the importance of host immunity in survival among patients with anal cancer. These findings encourage larger, prospective studies to further investigate TRL, its predictors, and its relationship with survival outcomes. Furthermore, the results of this study support ongoing efforts of clinical trials to investigate the potential role of immunotherapy in anal cancer.