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 cm 3 , 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.

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.

Underlying Bias in the Treatment of Pancreatic Cancer: Minorities Treated at the Same Facilities are Less Likely to Receive Neoadjuvant Therapy.

OBJECTIVE: To identify disparities in access to NAT for PDAC at the prehospital and intrahospital phases of care. SUMMARY OF BACKGROUND DATA: Delivery of NAT in PDAC is susceptible to disparities in access. There are limited data that accurately locate the etiology of disparities at the prehospital and intrahospital phases of care. METHODS: Retrospective cohort of patients ≥18 years old with clinical stage I-II PDAC from the 2010-2016 National Cancer Database. Multiple logistic regression was used to assess 2 sequential outcomes: (1) access to an NAT facility (prehospital phase) and (2) receipt of NAT at an NAT facility (intrahospital phase). RESULTS: A total of 36,208 patients were included for analysis in the prehospital phase of care. Higher education, longer travel distances, being treated at academic/research or integrated network cancer programs, and more recent year of diagnosis were independently associated with receipt of treatment at an NAT facility. All patients treated at NAT facilities (31,099) were included for the second analysis. Higher education level and receiving care at an academic/research facility were independently associated with increased receipt of NAT. NonBlack racial minorities (including American Indian, Asian, Pacific Islanders), being Hispanic, being uninsured, and having Medicaid insurance were associated with decreased receipt of NAT at NAT facilities. CONCLUSIONS: Non-Black racial minorities and Hispanic patients were less likely to receive NAT at NAT facilities compared to White and non-Hispanic patients, respectively. Discrepancies in administration of NAT while being treated at NAT facilities exist and warrant urgent further investigation.

Positron Emission Tomography/Magnetic Resonance Imaging (PET/MRI) Versus the Standard of Care Imaging in the Diagnosis of Peritoneal Carcinomatosis.

OBJECTIVE: To compare positron emission tomography (PET)/magnetic resonance imaging (MRI) to the standard of care imaging (SCI) for the diagnosis of peritoneal carcinomatosis (PC) in primary abdominopelvic malignancies. SUMMARY BACKGROUND DATA: Identifying PC impacts prognosis and management of multiple cancer types. METHODS: Adult subjects were prospectively and consecutively enrolled from April 2019 to January 2021. Inclusion criteria were: 1) acquisition of whole-body contrast-enhanced (CE) 18F-fluorodeoxyglucose PET/MRI, 2) pathologically confirmed primary abdominopelvic malignancies. Exclusion criteria were: 1) greater than 4 weeks interval between SCI and PET/MRI, 2) unavailable follow-up. SCI consisted of whole-body CE PET/computed tomography (CT) with diagnostic quality CT, and/or CE-CT of the abdomen and pelvis, and/or CE-MRI of the abdomen±pelvis. If available, pathology or surgical findings served as the reference standard, otherwise, imaging followup was used. When SCI and PET/MRI results disagreed, medical records were checked for management changes. Follow-up data were collected until August 2021. RESULTS: One hundred sixty-four subjects were included, 85 (52%) were female, and the median age was 60 years (interquartile range 50-69). At a subject level, PET/MRI had higher sensitivity (0.97, 95% CI 0.86-1.00) than SCI (0.54, 95% CI 0.37-0.71), P < 0.001, without a difference in specificity, of 0.95 (95% CI 0.90-0.98) for PET/MRI and 0.98 (95% CI 0.93-1.00) for SCI, P » 0.250. PET/MRI and SCI results disagreed in 19 cases. In 5/19 (26%) of the discordant cases, PET/MRI findings consistent with PC missed on SCI led to management changes. CONCLUSION: PET/MRI improves detection of PC compared with SCI which frequently changes management.

Disparities in Receipt of Adjuvant Therapy After Upfront Surgical Resection for Pancreatic Ductal Adenocarcinoma.

BACKGROUND: A multimodal approach of surgery and chemotherapy, with or without radiation, is the mainstay of therapy with curative-intent for resectable pancreatic ductal adenocarcinoma (PDAC). This study compared utilization trends and outcomes of upfront surgery with and without adjuvant therapy. METHODS: The National Cancer Database was queried for patients with a diagnosis of stage 1 or 2 PDAC who underwent upfront resection. Multivariable regression was applied to identify factors associated with initiation of adjuvant therapy. RESULTS: Of the 39,128 patients in the study, 67% initiated adjuvant therapy after resection, whereas 33% received upfront surgery alone. Receipt of adjuvant multimodal therapy increased from 59% in 2006 to 69% in 2017 (P < 0.0001). Non-white race was associated with lower odds of receiving adjuvant therapy after adjustment for income status, education attainment, and other variables (Hispanic/Spanish [odds ratio {OR}, 0.77; 95% confidence interval {CI}, 0.69-0.86] and non-Hispanic black [OR 0.84; 95% CI 0.78-0.91 vs non-Hispanic white; P < 0.001). The variables that contributed to receipt of adjuvant therapy were place of residence in high versus low education attainment area (OR 1.30; 95% CI 1.18-1.44; P < 0.0001) and lower odds for initiation of adjuvant therapy with increasing distance from the treating facility (> 50 miles [OR 0.51; 95% CI 0.47-0.54] vs <12.5 miles; P < 0.0001). The median unadjusted overall survival (OS) time was 18.2 months (95% CI 17.7-18.8 months) for upfront surgery alone and 25.3 months (95% CI 24.9-25.8 months) for surgery with adjuvant therapy. CONCLUSIONS: The patients who underwent upfront surgical resection for PDAC showed wide socioeconomic disparities in the use of adjuvant therapy independent of insurance status, facility type, or travel distance.

Patient Survival With ypT0N+ Following Neoadjuvant Therapy in Rectal Cancer.

BACKGROUND: After neoadjuvant therapy, pathologic analysis of rectal cancer resected specimens may show a complete response in the primary tissue cancer with residual tumor in the lymph nodes (ypT0N+). OBJECTIVES: The aim of this study was to describe the 5-year overall survival and factors associated with survival of ypT0N+ patients with rectal cancer who had neoadjuvant therapy followed by surgery and to compare these patients' survival with patients in other pathologic categories. DESIGN: We conducted a retrospective analysis. SETTINGS: We used the National Cancer Database. PATIENTS: We identified patients with rectal adenocarcinoma who underwent total neoadjuvant therapy or neoadjuvant chemoradiation followed by surgery between 2006 and 2016. Besides ypT0N+, 5 pathologic categories were identified: ypT0N0, ypT1-2N0, ypT3-4N0, ypT1-2N+, and ypT3-4N+. MAIN OUTCOME MEASURE: The primary outcome measure was 5-year overall survival. RESULTS: We included 30,751 patients with rectal adenocarcinoma. A total of 342 patients developed ypT0N+, of whom 181 (52.9%) received total neoadjuvant therapy. Among patients who received total neoadjuvant therapy, developing ypT0N+ was associated with a lower 5-year overall survival than ypT0N0 and ypT1-2N0. However, ypT0N+ disease was associated with a higher 5-year overall survival than ypT3-4N+. There were no differences in 5-year overall survival between ypT0N+ and ypT3-4N0 or ypT1-2N+. Similar findings were noticed among patients who received neoadjuvant chemoradiation and adjuvant chemotherapy. For patients with ypT0N+, older age, male gender, and higher number of positive lymph nodes were all associated with a decrease in the overall survival. LIMITATIONS: Limitations include the retrospective nature of this study, lack of variables describing the chemotherapy and radiation regimens used, and paucity of data on disease-specific survival or recurrence. CONCLUSIONS: Developing ypT0N+ was associated with a lower 5-year overall survival than ypT0N0 and ypT1-2N0. However, it was associated with a higher 5-year overall survival than ypT3-4N+. See Video Abstract at http://links.lww.com/DCR/B863 . SOBREVIDA DE LOS PACIENTES CON YPTN DESPUS DE LA TERAPIA NEOADYUVANTE EN EL CNCER DE RECTO: ANTECEDENTES:Después del tratamiento neoadyuvante en el cáncer de recto bajo, el análisis patológico de la pieza operatoria resecada, puede mostrar una respuesta patológica completa del tumor primario pero con tumor residual en los ganglios linfáticos (ypT0N+).OBJETIVOS:Describir la sobrevida general a 5 años y los factores asociados con la sobrevida de los pacientes ypT0N+ con cáncer de recto, que recibieron terapia neoadyuvante seguida de cirugía y comparar la sobrevida de estos pacientes con la de pacientes con otros estadios patológicos.DISEÑO:Realizamos un análisis retrospectivo.AJUSTES:Utilizamos la base de datos nacional del cáncer.PACIENTES:Identificamos pacientes con adenocarcinoma de recto que se sometieron a terapia neoadyuvante total, seguida de cirugía entre 2006 y 2016. Además de ypT0N +, se identificaron 5 categorías patológicas: ypT0N0, ypT1-2N0, ypT3-4N0, ypT1-2N+, e ypT3-4N+.PRINCIPAL MEDIDA DE RESULTADO:La medida de resultado principal fue la supervivencia general a 5 años.RESULTADOS:Se incluyeron 30.751 pacientes con adenocarcinoma de recto. Un total de 342 pacientes desarrollaron ypT0N+, de los cuales 181 (52,9%) recibieron terapia neoadyuvante total. Entre los pacientes que recibieron terapia neoadyuvante total, el desarrollo de ypT0N+ se asoció con una supervivencia general a 5 años más baja que ypT0N0 e ypT1-2N0. Sin embargo, la enfermedad ypT0N+ se asoció con una supervivencia general a 5 años más alta que ypT3-4N+. No hubo diferencias en la supervivencia global a 5 años entre ypT0N+ y ypT3-4N0 o ypT1-2N+. Se observaron hallazgos similares entre los pacientes que recibieron terapia neoadyuvante y quimioterapia adyuvante. Para los pacientes con ypT0N+, la edad avanzada, el sexo masculino y un mayor número de ganglios linfáticos positivos se asociaron con una disminución en la supervivencia general.LIMITACIONES:Las limitaciones incluyen la naturaleza retrospectiva del estudio, la falta de variables que describan los regímenes de quimioterapia y radiación utilizados y la escasez de datos sobre la supervivencia o la recurrencia específicas de la enfermedad.CONCLUSIONES:El desarrollo de ypT0N+ se asoció con una supervivencia general a 5 años más baja que ypT0N0 e ypT1-2N0. Sin embargo, se asoció con una supervivencia global a 5 años más alta que ypT3-4N+. Consulte Video Resumen en http://links.lww.com/DCR/B863 . (Traducción-Dr. Rodrigo Azolas ).

The efficacy and safety of cardio-protective therapy in patients with 5-FU (Fluorouracil)-associated coronary vasospasm.

BACKGROUND: Coronary vasospasm is a known side effect of 5-FU (fluorouracil) therapy. Beyond switching to non-5FU-based chemotherapy, there are no established treatments for 5-FU associated coronary vasospam. Our objective was to assess the safety and efficacy of re-challenge with 5-FU after pre-treatment with calcium channel blockers (CCBs) and long-acting nitrates among patients 5-FU associated coronary vasospasm. METHODS: We conducted a retrospective study of patients with 5-FU coronary vasospasm at a single academic center. By protocol, those referred to cardio-oncology received pre-treatment with either combination [nitrates and CCBs] or single-agent therapy [nitrates or CCBs]) prior to re-challenge with 5-FU. Our primary outcome was overall survival. Other important outcomes included progression-free survival and safety. RESULTS: Among 6,606 patients who received 5-FU from January 2001 to Dec 2020, 115 (1.74%) developed coronary vasospasm. Of these 115 patients, 81 patients continued 5-FU therapy, while 34 stopped. Of the 81 who continued, 78 were referred to cardio-oncology and prescribed CCBs and/or nitrates prior to subsequent 5-FU, while the remaining 3 continued 5-FU without cardiac pre-treatment. Of the 78, 56.4% (44/78) received both nitrates and CCBs, 19.2% (15/78) received CCBs alone, and 24.4% (19/78) received nitrates alone. When compared to patients who stopped 5-FU, those who continued 5-FU after pre-treatment (single or combination therapy) had a decreased risk of death (HR 0.42, P = 0.005 [95% CI 0.23-0.77]) and a trend towards decreased cancer progression (HR 0.60, P = 0.08 [95% CI 0.34-1.06]). No patient in the pre-treatment group had a myocardial infarct after re-challenge; however, chest pain (without myocardial infarction) recurred in 19.2% (15/78) among those who received cardiac pre-treatment vs. 66.7% (2/3) among those who did not (P = 0.048). There was no difference in efficacy or the recurrence of vasospasm among patients who received pre-treatment with a single agent (nitrates or CCBs) or combination therapy (14.7% (5/34) vs. 25.0% (11/44), P = 0.26). CONCLUSION: Re-challenge after pre-treatment with CCBs and nitrates guided by a cardio-oncology service was safe and allowed continued 5-FU therapy.

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.

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.

Neuroendocrine and Adrenal Tumors, Version 2.2021, NCCN Clinical Practice Guidelines in Oncology.

The NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines) for Neuroendocrine and Adrenal Gland Tumors focus on the diagnosis, treatment, and management of patients with neuroendocrine tumors (NETs), adrenal tumors, pheochromocytomas, paragangliomas, and multiple endocrine neoplasia. NETs are generally subclassified by site of origin, stage, and histologic characteristics. Appropriate diagnosis and treatment of NETs often involves collaboration between specialists in multiple disciplines, using specific biochemical, radiologic, and surgical methods. Specialists include pathologists, endocrinologists, radiologists (including nuclear medicine specialists), and medical, radiation, and surgical oncologists. These guidelines discuss the diagnosis and management of both sporadic and hereditary neuroendocrine and adrenal tumors and are intended to assist with clinical decision-making. This article is focused on the 2021 NCCN Guidelines principles of genetic risk assessment and counseling and recommendations for well-differentiated grade 3 NETs, poorly differentiated neuroendocrine carcinomas, adrenal tumors, pheochromocytomas, and paragangliomas.

Circulating Tumor DNA Predicts Pathologic and Clinical Outcomes Following Neoadjuvant Chemoradiation and Surgery for Patients With Locally Advanced Rectal Cancer.

PURPOSE: This study was designed to assess the ability of perioperative circulating tumor DNA (ctDNA) to predict surgical outcome and recurrence following neoadjuvant chemoradiation for locally advanced rectal cancer (LARC). MATERIALS AND METHODS: Twenty-nine patients with newly diagnosed LARC treated between January 2014 and February 2018 were enrolled. Patients received long-course neoadjuvant chemoradiation prior to surgery. Plasma ctDNA was collected at baseline, preoperatively, and postoperatively. Next-generation sequencing was used to identify mutations in the primary tumor, and mutation-specific droplet digital polymerase chain reaction was used to assess mutation fraction in ctDNA. RESULTS: The median age was 54 years. The overall margin-negative, node-negative resection rate was 73% and was significantly higher among patients with undetectable preoperative ctDNA (n = 17, 88%) versus patients with detectable preoperative ctDNA (n = 9, 44%; P = .028). Undetectable ctDNA was also associated with more favorable neoadjuvant rectal scores (univariate linear regression, P = .029). Recurrence-free survival (RFS) was calculated for the subset (n = 19) who both underwent surgery and had postoperative ctDNA available. At a median follow-up of 20 months, patients with detectable postoperative ctDNA experienced poorer RFS (hazard ratio, 11.56; P = .007). All patients (4 of 4) with detectable postoperative ctDNA recurred (positive predictive value = 100%), whereas only 2 of 15 patients with undetectable ctDNA recurred (negative predictive value = 87%). CONCLUSION: Among patients treated with neoadjuvant chemoradiation for LARC, patients with undetectable preoperative ctDNA were more likely to have a favorable surgical outcome as measured by the rate of margin-negative, node-negative resections and neoadjuvant rectal score. Furthermore, we have confirmed prior reports indicating that detectable postoperative ctDNA is associated with worse RFS. Future prospective study is needed to assess the potential for ctDNA to assist with personalizing treatment for LARC.

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.

Evaluation of the Diagnostic Performance of Positron Emission Tomography/Magnetic Resonance for the Diagnosis of Liver Metastases.

OBJECTIVE: The aim of this study was to compare the performance of positron emission tomography (PET)/magnetic resonance (MR) versus stand-alone PET and stand-alone magnetic resonance imaging (MRI) in the detection and characterization of suspected liver metastases. MATERIALS AND METHODS: This multi-institutional retrospective performance study was approved by the institutional review boards and was Health Insurance Portability and Accountability Act compliant, with waiver of informed consent. Seventy-nine patients with confirmed solid extrahepatic malignancies who underwent upper abdominal PET/MR between February 2017 and June 2018 were included. Where focal hepatic lesions were identified, the likelihood of a diagnosis of a liver metastasis was defined on an ordinal scale for MRI, PET, and PET/MRI by 3 readers: 1 nuclear medicine physician and 2 radiologists. The number of lesions per patient, lesion size, and involved hepatic segments were recorded. Proof of metastases was based on histopathologic correlation or clinical/imaging follow-up. Diagnostic performance was assessed using sensitivity, specificity, positive and negative predictive values, and receiver operator characteristic curve analysis. RESULTS: A total of 79 patients (53 years, interquartile range, 50-68; 43 men) were included. PET/MR had a sensitivity of 95%, specificity of 97%, positive predictive value of 97%, and negative predictive value of 95%. The sensitivity, specificity, positive predictive value, and negative predictive value of MRI were 88%, 98%, 98%, and 90% and for PET were 83%, 97%, 97%, and 86%, respectively. The areas under the curve for PET/MRI, MRI, and PET were 95%, 92%, and 92%, respectively. CONCLUSIONS: Contrast-enhanced PET/MR has a higher sensitivity and negative predictive value than either PET or MRI alone in the setting of suspected liver metastases. Fewer lesions were characterized as indeterminate by PET/MR in comparison with PET and MRI. This superior performance could potentially impact treatment and management decisions for patients with suspected liver metastases.

Impact of PET/MRI in the Treatment of Pancreatic Adenocarcinoma: a Retrospective Cohort Study.

PURPOSE: Imaging is central to the diagnosis and management of Pancreatic Ductal Adenocarcinoma (PDAC). This study evaluated if positron emission tomography (PET)/magnetic resonance imaging (MRI) elicited treatment modifications in PDAC when compared to standard of care imaging (SCI). PROCEDURES: This retrospective study included consecutive patients with PDAC who underwent 2-deoxy-2-[18F]fluoro-D-glucose ([18F]F-FDG) PET/MRI and SCI from May 2017 to January 2019. SCI included abdominal computed tomography (CT), MRI, and/or PET/CT. For patients who had more than one pair of PET/MRI and SCI, each management decision was independently evaluated. Treatment strategies based on each modality were extracted from electronic medical records. Follow-up was evaluated until January 2020. RESULTS: Twenty-five patients underwent 37 PET/MRI's, mean age was 65 ± 9 years and 13 (13/25, 52 %) were men. 49 % (18/37, 95 % CI 33-64 %) of the PET/MRI scans changed clinical management. Whether the SCI included a PET/CT or not did not significantly modify the probability of management change (OR = 0.9, 95 % CI 0.2-4, p = 1). One hundred percent (33/33) of the available follow-up data confirmed PET/MRI findings. CONCLUSIONS: PET/MRI significantly changed PDAC management, consistently across the different SCI modalities it was compared to. These findings suggest a role for PET/MRI in the management of PDAC.

Improving staging of rectal cancer in the pelvis: the role of PET/MRI.

PURPOSE: The role of positron emission tomography/magnetic resonance (PET/MR) in evaluating the local extent of rectal cancer remains uncertain. This study aimed to investigate the possible role of PET/MR versus magnetic resonance (MR) in clinically staging rectal cancer. METHODS: This retrospective two-center cohort study of 62 patients with untreated rectal cancer investigated the possible role of baseline staging PET/MR versus stand-alone MR in determination of clinical stage. Two readers reviewed T and N stage, mesorectal fascia involvement, tumor length, distance from the anal verge, sphincter involvement, and extramural vascular invasion (EMVI). Sigmoidoscopy, digital rectal examination, and follow-up imaging, along with surgery when available, served as the reference standard. RESULTS: PET/MR outperformed MR in evaluating tumor size (42.5 ± 21.03 mm per the reference standard, 54 ± 20.45 mm by stand-alone MR, and 44 ± 20 mm by PET/MR, P = 0.004), and in identifying N status (correct by MR in 36/62 patients [58%] and by PET/MR in 49/62 cases [79%]; P = 0.02) and external sphincter infiltration (correct by MR in 6/10 and by PET/MR in 9/10; P = 0.003). No statistically significant differences were observed in relation to any other features. CONCLUSION: PET/MR provides a more precise assessment of the local extent of rectal cancers in evaluating cancer length, N status, and external sphincter involvement. PET/MR offers the opportunity to improve clinical decision-making, especially when evaluating low rectal tumors with possible external sphincter involvement.

Refusal of surgery for colon cancer: Sociodemographic disparities and survival implications among US patients with resectable disease.

BACKGROUND: We aimed to identify factors associated with refusal of surgery among patients with colon cancer. METHODS: This 2004-2016 NCDB retrospective study identified AJCC stage I-III colon cancer patients who were recommended surgery. Multivariable logistic regression defined adjusted odds ratios of refusing treatment, with sociodemographic and clinical covariates. Treatment propensity-adjusted Cox proportional hazard ratios defined differential survival stratified by clinical stage, controlling for potential confounders. RESULTS: Of 170,594 patients recommended surgery, 1116 refused. Increased rates of surgery refusal were associated with older age, African American race, CDCC>3, and female sex. Decreased rates of surgery refusal were associated with higher income and private insurance. Stratifying by stage, refusal rates among African Americans remained disparately high. Refusal of surgery was associated with worse overall survival. CONCLUSIONS: Disparate rates of refusal of surgery for resectable colon cancer by race and other sociodemographic factors highlight potential treatment adherence reinforcement beneficiaries, necessitating further study of shared decision-making.