Preoperative Treatment of Locally Advanced Rectal Cancer.

BACKGROUND: Pelvic radiation plus sensitizing chemotherapy with a fluoropyrimidine (chemoradiotherapy) before surgery is standard care for locally advanced rectal cancer in North America. Whether neoadjuvant chemotherapy with fluorouracil, leucovorin, and oxaliplatin (FOLFOX) can be used in lieu of chemoradiotherapy is uncertain. METHODS: We conducted a multicenter, unblinded, noninferiority, randomized trial of neoadjuvant FOLFOX (with chemoradiotherapy given only if the primary tumor decreased in size by <20% or if FOLFOX was discontinued because of side effects) as compared with chemoradiotherapy. Adults with rectal cancer that had been clinically staged as T2 node-positive, T3 node-negative, or T3 node-positive who were candidates for sphincter-sparing surgery were eligible to participate. The primary end point was disease-free survival. Noninferiority would be claimed if the upper limit of the two-sided 90.2% confidence interval of the hazard ratio for disease recurrence or death did not exceed 1.29. Secondary end points included overall survival, local recurrence (in a time-to-event analysis), complete pathological resection, complete response, and toxic effects. RESULTS: From June 2012 through December 2018, a total of 1194 patients underwent randomization and 1128 started treatment; among those who started treatment, 585 were in the FOLFOX group and 543 in the chemoradiotherapy group. At a median follow-up of 58 months, FOLFOX was noninferior to chemoradiotherapy for disease-free survival (hazard ratio for disease recurrence or death, 0.92; 90.2% confidence interval [CI], 0.74 to 1.14; P = 0.005 for noninferiority). Five-year disease-free survival was 80.8% (95% CI, 77.9 to 83.7) in the FOLFOX group and 78.6% (95% CI, 75.4 to 81.8) in the chemoradiotherapy group. The groups were similar with respect to overall survival (hazard ratio for death, 1.04; 95% CI, 0.74 to 1.44) and local recurrence (hazard ratio, 1.18; 95% CI, 0.44 to 3.16). In the FOLFOX group, 53 patients (9.1%) received preoperative chemoradiotherapy and 8 (1.4%) received postoperative chemoradiotherapy. CONCLUSIONS: In patients with locally advanced rectal cancer who were eligible for sphincter-sparing surgery, preoperative FOLFOX was noninferior to preoperative chemoradiotherapy with respect to disease-free survival. (Funded by the National Cancer Institute; PROSPECT ClinicalTrials.gov number, NCT01515787.).

Current Practices in Hepatic Artery Infusion (HAI) Chemotherapy: An International Survey of the HAI Consortium Research Network.

BACKGROUND: An increasing number of hepatic artery infusion (HAI) programs have been established worldwide. Practice patterns for this complex therapy across these programs have not been reported. This survey aimed to identify current practice patterns in HAI therapy with the long-term goal of defining best practices and performing prospective studies. METHODS: Using SurveyMonkeyTM, a 28-question survey assessing current practices in HAI was developed by 12 HAI Consortium Research Network (HCRN) surgical oncologists. Content analysis was used to code textual responses, and the frequency of categories was calculated. Scores for rank-order questions were generated by calculating average ranking for each answer choice. RESULTS: Thirty-six (72%) HCRN members responded to the survey. The most common intended initial indications for HAI at new programs were unresectable colorectal liver metastases (uCRLM; 100%) and unresectable intrahepatic cholangiocarcinoma (uIHC; 56%). Practice patterns evolved such that uCRLM (94%) and adjuvant therapy for CRLM (adjCRLM; 72%) have become the most common current indications for HAI at established centers. Referral patterns for pump placement differed between uCRLM and uIHC, with most patients referred while receiving second- and first-line therapy, respectively, with physicians preferring to evaluate patients for HAI while receiving first-line therapy for CRLM. Concern for extrahepatic disease was ranked as the most important factor when considering a patient for HAI. CONCLUSIONS: Indication and patient selection factors for HAI therapy are relatively uniform across most HCRN centers. The increasing use of adjuvant HAI therapy and overall consistency of practice patterns among HCRN centers provides a robust environment for prospective data collection and randomized clinical trials.

Impact of new cancer therapies on outpatient treatment delivery for colorectal cancer: A population-based study.

We investigated the impact of new systemic therapies approved in Canada for colorectal cancer on the frequency, intensity and duration of oncology clinic and infusion visits over five treatment phases from diagnosis (P1, P3) to treatment (P2, P4) of primary and metastatic disease, respectively, and during the last 6 months of life (P5). In total, 15,157 adult patients with newly diagnosed colorectal cancer and referred between 2000 and 2012 to any cancer clinic in British Columbia, Canada, were included. Frequency, intensity and duration of medical oncology clinic visits (CVs), oncology infusions (OIs) and oncology prescriptions (OPs) were measured by treatment phase. Mean, total and adjusted total duration for CVs increased for P1-5. CVs increased in P1-5, and in P1-4 when adjusted by treatment length. Adjusted and unadjusted OIs decreased in P1 coinciding with the introduction of an oral treatment option, but increased in P2-5. Mean OI duration increased in P1-5, while total and adjusted total decreased in P1 and increased in P2-5. OPs increased in P2-4, but were unchanged in P1 and P5. Multi-fold increases in resources and time required per patient were also observed, which have significant implications for demand projections in cancer care planning and delivery. In conclusion, patients required more visits in almost all treatment phases, visits on average took longer and patients were in treatment for longer periods of time.

The Impact of Chronic Kidney Disease in Patients With Locally Advanced Rectal Cancer Treated With Neoadjuvant Chemoradiation.

BACKGROUND: Patients with chronic kidney disease are commonly excluded from clinical trials. The impact of chronic kidney disease on outcomes in patients with locally advanced rectal cancer has not been previously studied. OBJECTIVE: This study aimed to investigate the impact of chronic kidney disease on outcomes in patients with locally advanced rectal cancer. DESIGN: This is a multi-institutional, retrospective cohort study. SETTINGS: This study was conducted at academic and community cancer centers participating in the Canadian Health Outcomes Research Database Consortium Rectal Cancer Database. PATIENTS: Consecutive patients with locally advanced rectal cancer undergoing neoadjuvant chemoradiation before curative-intent surgery from 2005 to 2013 were selected. MAIN OUTCOME MEASURES: Disease-free survival, overall survival, pathologic complete response, and neoadjuvant chemotherapy/radiotherapy completion rate were the primary outcomes measured. RESULTS: A total of 1254 patients were included. Median age was 62, and 29%/69% had clinical stage II and III disease. Median estimated creatinine clearance was 93 mL/min, with 11% <60 mL/min (n = 136). There was no significant difference in the completion rate of neoadjuvant chemotherapy (82% vs 85%, p = 0.36) or radiotherapy (93% vs 95%, p = 0.45) between patients with and without chronic kidney disease. Patients with chronic kidney disease were less likely to receive adjuvant chemotherapy (63% vs 77%, p < 0.01). On multivariate analysis, patients with chronic kidney disease had decreased disease-free survival (HR, 1.37; 95% CI, 1.03-1.82; p = 0.03) but not overall survival (HR, 1.23; 95% CI, 0.88-1.75; p = 0.23) or pathologic complete response (OR, 0.83; 95% CI, 0.50-1.39; p = 0.71). LIMITATIONS: This study was limited by its retrospective design and by limited events for overall survival analysis. CONCLUSIONS: In patients with locally advanced rectal cancer undergoing neoadjuvant chemoradiation, baseline chronic kidney disease was associated with less use of adjuvant chemotherapy and decreased disease-free survival. Chronic kidney disease was not independently associated with neoadjuvant chemotherapy/radiotherapy completion rate, pathologic complete response, or overall survival. These data suggest that patients with locally advanced rectal cancer with chronic kidney disease may have distinct outcomes and, accordingly, the results of landmark clinical trials may not be generalizable to this population. See Video Abstract at http://links.lww.com/DCR/B694. LA REPERCUSIN DE LA ENFERMEDAD RENAL CRNICA EN PACIENTES CON CNCER DE RECTO LOCALMENTE AVANZADO TRATADOS CON QUIMIORRADIOTERAPIA NEOADYUVANTE: ANTECEDENTES:Los pacientes con enfermedad renal crónica generalmente se excluyen de los ensayos clínicos. La repercusión de la enfermedad renal crónica en el desenlace en pacientes con cáncer de recto localmente avanzado no se ha estudiado previamente.OBJETIVO:Investigar la repercusión de la enfermedad renal crónica en los desenlaces en pacientes con cáncer de recto localmente avanzado.DISEÑO:Estudio de cohorte retrospectivo multiinstitucional.ESCENARIO:Centros oncológicos académicos y comunitarios que participan en la base de datos de cáncer rectal del consorcio CHORD.PACIENTES:Pacientes consecutivos con cáncer de recto localmente avanzado, tratados con quimiorradioterapia neoadyuvante, previa a la cirugía con intención curativa del 2005 al 2013.PRINCIPALES VARIABLES EVALUADAS:Sobrevida libre de enfermedad, sobrevida global, respuesta patológica completa, tasa de conclusión de quimioterapia / radioterapia neoadyuvante.RESULTADOS:Se incluyeron 1254 pacientes. El promedio de edad fue de 62, y el 29% / 69% tenían enfermedad en estadio clínico II y III, respectivamente. El promedio de la depuración de creatinina estimada fue de 93 mililitros / minuto, con un 11% <60 mililitros / minuto (n = 136). No hubo diferencias significativas en la tasa de conclusión de la quimioterapia neoadyuvante (82% vs 85%, p = 0,36) o radioterapia (93% vs 95%, p = 0,45) entre pacientes con y sin enfermedad renal crónica. Los pacientes con enfermedad renal crónica tenían menos probabilidades de recibir quimioterapia adyuvante (63% contra el 77%, p <0,01). En el análisis multivariado, los pacientes con enfermedad renal crónica tenían una sobrevida libre de enfermedad menor (HR 1,37, IC 95% 1,03-1,82, p = 0,03) pero no en la sobrevida global (HR 1,23, IC 95% 0,88-1,75, p = 0,23) o respuesta patológica completa (OR 0,83, IC 95% 0,50-1,39, p = 0,71).LIMITACIONES:Diseño retrospectivo y acontecimientos limitados para el análisis de sobrevida global.CONCLUSIONES:En pacientes con cáncer de recto localmente avanzado tratados con quimiorradioterapia neoadyuvante, la enfermedad renal crónica de base se asoció con un menor uso de quimioterapia adyuvante y una menor sobrevida libre de enfermedad. La enfermedad renal crónica no se asoció de forma independiente con la tasa de conclusión de la quimioterapia / radioterapia neoadyuvante, la respuesta patológica completa o la sobrevida global. Estos datos sugieren que los pacientes con cáncer de recto localmente avanzado con enfermedad renal crónica pueden tener resultados distintos y, en consecuencia, los resultados de los ensayos clínicos de referencia pueden no ser generalizables a esta población. Consulte Video Resumen en http://links.lww.com/DCR/B694.

Outcomes of Surgical and Chemotherapeutic Treatments of Goblet Cell Carcinoid Tumors of the Appendix.

BACKGROUND: Goblet cell carcinoids (GCCs) of the appendix are rare mucinous neoplasms, for which optimal therapy is poorly described. We examined prognostic clinical and treatment factors in a population-based cohort. METHODS: Patients diagnosed with GCC from 1984 to 2014 were identified from the British Columbia Cancer Agency and the Vancouver Lower Mainland Pathology Archive. RESULTS: Of 88 cases with confirmed appendiceal GCCs, clinical data were available in 86 cases (annual population incidence: 0.66/1,000,000). Median age was 54 years (range 25-91) and 42 patients (49%) were male. Metastasis at presentation was the strongest predictor of overall survival (OS), with median OS not reached for stage I-III patients, and measuring 16.2 months [95% confidence interval (CI) 9.1-29] for stage IV patients. In 67 stage I-III patients, 51 (76%) underwent completion hemicolectomy and 9 (17%) received adjuvant 5-fluorouracil-based chemotherapy. No appendicitis at initial presentation and Tang B histology were the only prognostic factors, with inferior 5-year recurrence-free survival (53 vs. 83% with appendicitis, p = 0.02; 45% Tang B vs. 89% Tang A, p < 0.01). Of 19 stage IV patients, 10 (62.5%) received 5-fluorouracil-based chemotherapy and 11 (61%) underwent multiorgan resection (MOR) ± hyperthermic intraperitoneal chemotherapy (HIPEC). Low mitotic rate and MOR ± HIPEC were associated with improved 2-year OS, but only MOR ± HIPEC remained significant on multivariate analysis (hazard ratio 5.4, 95% CI 1.4-20.9; p = 0.015). CONCLUSIONS: In this population-based cohort, we demonstrate excellent survival outcomes in stage I-III appendiceal GCCs and clinical appendicitis. Hemicolectomy remains the standard treatment. In metastatic disease, outcomes remain poor, although MOR ± HIPEC may improve survival.

Prognostic Factors for Locoregional Recurrence in Neuroendocrine Tumors of the Rectum.

BACKGROUND: Optimal management of rectal neuroendocrine tumors is not yet well defined. Various pathologic factors, particularly tumor size, have been proposed as prognostic markers. OBJECTIVE: We characterized sequential patients diagnosed with rectal neuroendocrine tumors in a population-based setting to determine whether tumor size and other pathologic markers could be useful in guiding locoregional management. DESIGN: This study is a retrospective analysis of data from the British Columbia provincial cancer registry. SETTINGS: The study was conducted at a tertiary care center. PATIENTS: Sequential patients diagnosed with rectal neuroendocrine tumors between 1999 and 2011 were identified. Neuroendocrine tumors were classified as G1 and G2 tumors with a Ki-67 ≤20% and/or mitotic count ≤20 per high-power field. MAIN OUTCOME MEASURES: Baseline clinicopathologic data including TNM staging, depth of invasion, tumor size, treatment modalities, and outcomes including survival data were measured. RESULTS: Of 91 rectal neuroendocrine tumors, the median patient age was 58 years, and 35 were men. Median tumor size was 6 mm. Median length of follow-up was 58.1 months, with 3 patients presenting with stage IV disease. Treatment included local ablation (n = 5), local excision (n = 79), surgical resection (n = 4), and pelvic radiation (n = 1; T3N1 tumor). Final margin status was positive in 17 cases. Local relapse occurred in 8 cases and 1 relapse to bone 13 months after T3N1 tumor resection. Univariate analysis demonstrated an association between local relapse and Ki-67, mitotic count, grade, and lymphovascular invasion (p < 0.01). Larger tumor size was associated with decreased disease-free survival. LIMITATIONS: Sample size was 91 patients in the whole provincial population over a 13-year time period because of the low incidence of rectal neuroendocrine tumors. CONCLUSIONS: In this population-based cohort, rectal neuroendocrine tumors generally presented with small, early tumors and were treated with local excision or surgical resection without pelvic radiation. Pathologic markers play a role in risk stratification and prognostication. See Video Abstract at http://links.lww.com/DCR/A514.

The utility of abbreviated patient-reported outcomes for predicting survival in early stage colorectal cancer.

BACKGROUND: Patient-reported outcomes (PROs) are increasingly used in clinical settings. Prior research suggests that PROs collected at baseline may be associated with cancer survival, but most of those studies were conducted in patients with breast or lung cancer. The objective of this study was to determine the correlation between prospectively collected PROs and cancer-specific outcomes in patients with early stage colorectal cancer. METHODS: Patients who had newly diagnosed stage II or III colorectal cancer from 2009 to 2010 and had a consultation at the British Columbia Cancer Agency completed the brief Psychosocial Screen for Cancer (PSSCAN) questionnaire, which collects data on patients' perceived social supports, quality of life (QOL), anxiety and depression, and general health. PROs from the PSSCAN were linked with the Gastrointestinal Cancers Outcomes Database, which contains information on patient and tumor characteristics, treatment details, and cancer outcomes. Cox regression models were constructed for overall survival (OS), and Fine and Gray regression models were developed for disease-specific survival (DSS). RESULTS: In total, 692 patients were included. The median patient age was 67 years (range, 26-95 years), and the majority had colon cancer (61%), were diagnosed with stage III disease (54%), and received chemotherapy (58%). In general, patients felt well supported and reported good overall health and QOL. On multivariate analysis, increased fatigue was associated with worse OS (hazard ratio [HR], 1.99; P = .00007) and DSS (HR, 1.63; P = .03), as was lack of emotional support (OS: HR, 4.36; P = .0003; DSS: HR, 1.92; P = .02). CONCLUSIONS: Although most patients described good overall health and QOL and indicated that they were generally well supported, patients who experienced more pronounced fatigue or lacked emotional support had a higher likelihood of worse OS and DSS. These findings suggest that abbreviated PROs can inform and assist clinicians to identify patients who have a worse prognosis and may need more vigilant follow-up. Cancer 2017;123:1839-1847. © 2017 American Cancer Society.

Prophylactic versus reactive treatment of acneiform skin rashes from epidermal growth factor receptor inhibitors in metastatic colorectal cancer.

PURPOSE: There are concerns regarding potential negative effects of prophylactic treatment of epidermal growth factor receptor (EGFR)-inhibitor-related rashes on metastatic colorectal cancer (mCRC) outcomes. We aimed to characterize treatment patterns of EGFR-inhibitor-induced rashes and evaluate prophylactic versus reactive approaches to rash management in relation to overall survival (OS). METHODS: Patients diagnosed with KRAS wild-type mCRC from July 2010 to June 2012 in British Columbia and prescribed cetuximab or panitumumab were reviewed to describe patterns of use of oral antibiotics and steroid creams. Using Cox regression, the relationship between prophylactic versus reactive rash management and OS was characterized. RESULTS: A total 119 patients were analyzed: median age was 63 years, 61 % were male, 34 % received cetuximab, 66 % received panitumumab, and median number of EGFR inhibitor treatment was nine cycles. Rash occurred in >90 % of patients, and reactive was favored over prophylactic treatment (66 vs. 34 %). Older patients and those with Eastern Cooperative Oncology Group (ECOG) performance status 0/1 were more likely to receive prophylactic creams (44 vs. 20 % for age <60, p = 0.01) and oral antibiotics (62 vs. 12 % for ECOG ≥2, p = 0.01), respectively. Median OS was 7.0 months. The number of treatment cycles and OS were similar in both prophylactic and reactive groups (both p > 0.05). In Cox regression, ECOG >2 correlated with worse survival (hazard ratio (HR) 22.01, 95 % confidence interval (CI) 5.25-92.30, p < 0.01). However, survival outcomes were similar between patients prescribed antibiotics prophylactically versus reactively (HR = 1.10, 95 % CI 0.43-2.80, p = 0.85), and steroid creams prophylactically versus reactively (HR = 2.00, 95 % CI 0.58-6.92, p = 0.27). CONCLUSION: Prophylactic treatment of EGFR-inhibitor-related rashes is associated with similar outcomes compared to reactive rash treatment in mCRC.

Adjuvant chemotherapy use and outcomes of patients with high-risk versus low-risk stage II colon cancer.

BACKGROUND: Adjuvant chemotherapy (AC) is frequently considered in patients with stage II colon cancer who are considered to be at high risk. However, to the authors' knowledge, the survival benefits associated with AC in these patients remain largely unproven. In the current study, the authors sought to examine the use of AC in patients with AJCC stage II colon cancer and to compare the impact of AC on outcomes in patients with high-risk versus low-risk disease in a population-based setting. METHODS: Patients with stage II colon cancer who were evaluated at 1 of 5 regional cancer centers in British Columbia from 1999 to 2008 were analyzed. Kaplan-Meier and Cox regression methods were used to correlate high-risk versus low-risk status and receipt of AC with recurrence-free survival (RFS), disease-specific survival (DSS), and overall survival (OS). RESULTS: A total of 1697 patients were identified: 1286 (76%) with high-risk and 411 (24%) with low-risk disease, among whom 373 (29%) and 51 (12%),respectively, received AC. Individuals with high-risk disease treated with AC were younger (median age, 62 years vs 72 years; P<.001) and had better Eastern Cooperative Oncology Group performance status (0/1: 47% vs 33%; P = .001). For high-risk patients, AC was associated with improved OS (hazard ratio [HR], 0.65; 95% confidence interval [95% CI], 0.50-0.83 [P = .001]). However, no significant benefits with regard to RFS or DSS were observed. Subgroup analyses revealed that AC in patients with T4 disease was associated with significantly improved RFS (HR, 0.63; 95% CI, 0.42-0.95 [P = .03]), DSS (HR, 0.59; 95% CI, 0.37-0.93 [P = .02]), and OS (HR, 0.50; 95% CI, 0.33-0.77 [P = .002]). For patients with low-risk disease, AC was associated with inferior RFS (HR, 2.18; 95% CI, 1.00-4.79 [P = .05]) and DSS (HR, 3.01; 95% CI, 1.10-8.23 [P = .03]). CONCLUSIONS: In this population-based analysis, AC was associated with an OS advantage in high-risk patients, most likely due to patient selection. RFS, DSS, and OS benefits were mainly observed in patients with T4 disease, suggesting a limited role for AC in patients deemed to be high risk by non-T4 features.

Phase 2 study of MK-2206, an allosteric inhibitor of AKT, as second-line therapy for advanced gastric and gastroesophageal junction cancer: A SWOG cooperative group trial (S1005).

BACKGROUND: The AKT inhibitor MK-2206 at a dose of 60 mg every other day was evaluated in gastric/gastroesophageal junction cancers. METHODS: Patients who had progressed after first-line treatment were eligible. Pertinent eligibility criteria included adequate organ function, a fasting serum glucose level ≤ 150 mg/dL, and less than grade 2 malabsorption or chronic diarrhea. MK-2206 was given orally (60 evaluable patients required). The primary endpoint was overall survival, and a median survival of 6.5 months (power, 89%; significance level, 0.07) was considered encouraging for further investigation. RESULTS: Seventy patients were included in the final analyses. The median age was 59.8 years (range, 30.4-86.7 years); 70% were male, 89% were white, and 7% were Asian. There were 2 deaths possibly related to the study drug (cardiac arrest and respiratory failure). Grade 4 adverse events included hyperglycemia, anemia, and lung infection (1 each). Grade 3 adverse events occurred in < 5% of patients except for fatigue (6%). Other adverse events (all grades) included anemia (17%), anorexia (30%), diarrhea (26%), fatigue (50%), hyperglycemia (30%), nausea (40%), vomiting (22%), dry skin (19%), maculopapular rash (30%), and acneiform rash (13%). The response rate was 1%, the median progression-free survival was 1.8 months (95% confidence interval, 1.7-1.8 months), and the median overall survival was 5.1 months (95% confidence interval, 3.7-9.4 months) CONCLUSIONS: MK-2206 as second-line therapy was well tolerated by an unselected group of patients with gastric/gastroesophageal junction cancers, but it did not have sufficient activity (response rate, 1%; overall survival, 5.1 months) to warrant further testing in this population.

Association between palliative resection of the primary tumor and overall survival in a population-based cohort of metastatic colorectal cancer patients.

BACKGROUND: The impact of palliative resection of the primary tumor on outcomes in patients with metastatic colorectal cancer (mCRC) remains unclear. The primary objective of this study was to evaluate the association between palliative resection and overall survival (OS) in a population-based cohort of mCRC. METHODS: Patients diagnosed with mCRC between 2006 and 2008 and treated at the BC Cancer Agency were reviewed. Survival analysis was conducted using Kaplan-Meier methods. Cox proportional hazards regression models were fitted to evaluate the relationship between palliative resection and OS while controlling for potential confounders, such as age, gender, Eastern Cooperative Oncology Group status, carcinoembryonic antigen level, primary tumor location, metastatic site and number, and receipt of systemic therapy. To adjust for the heterogeneity and selection bias between the group that underwent palliative resection and the group that did not, a propensity score-matched analysis was also performed. RESULTS: A total of 517 patients were included. Among these cases, 378 (73 %) patients underwent palliative resection of their primary tumor, and 139 (27 %) patients did not. A total of 327 patients (63 %) were treated with palliative chemotherapy. Palliative resection was associated with a longer median OS (17.9 vs. 7.9 months) and more favorable unadjusted and adjusted hazard ratios (HRs) for death (HR 0.46, 95 % CI 0.37-0.56, p < 0.0001 and HR 0.56, 95 % CI 0.40-0.78, p = 0.0007, respectively) when compared with no resection. In a propensity score-matched analysis, prognosis was also more favorable in the resected group (p = 0.0017). CONCLUSIONS: In this cohort of mCRC patients, palliative resection of the primary tumor was associated with improved OS.

Kinetic Profiling of RAS Mutations With Circulating Tumor DNA in the Canadian Cancer Trials Group CO.26 Trial Suggests the Loss of RAS Mutations in Neo-RAS-Wildtype Metastatic Colorectal Cancer Is Transient.

PURPOSE: In metastatic colorectal cancer (mCRC), RAS mutations drive resistance to anti-epidermal growth factor receptor antibodies. It is unclear whether RAS mutations ever become clonally undetectable. METHODS: CO.26 was a phase II clinical trial that assessed durvalumab + tremelimumab in heavily pretreated mCRC. RAS mutation status was tracked over time using circulating tumor DNA (ctDNA) sequencing at baseline, week 8, and on progression. RESULTS: Among the 95 patients with KRAS/NRAS mutations in their archival tumor tissue, 6.3% (6/95) had undetectable RAS mutations in ctDNA collected at baseline or week 8 of the CO.26 study. Of these, 67% (4/6) of disappearances were transient, with the same mutation reappearing with progressive disease. In three cases, the simultaneous persistence of other preexisting CRC-associated truncal mutations could not be demonstrated, suggestive of low tumor shedding of ctDNA, leaving the incidence of true clonal reversion to RAS-wildtype (WT) possibly as low as 3.2% (3/95). Fewer patients in the neo-RAS-WT group (33%) had greater than four lesions at trial baseline compared with patients with persistent RAS mutations (75%), P = .046. The likelihood of synchronous metastases at cancer diagnosis (33% v 63%; P = .15) or liver metastases at trial baseline (50% v 68.5%; P = .17) was not significantly different between patients with disappearing versus persistent RAS mutations. Overall survival from stage IV diagnosis (hazard ratio, 0.77 [95% CI, 0.35 to 1.72]; P = .52) was not significantly different between those with disappearing versus persistent RAS mutations. The disappearance of RAS mutations was not associated with primary tumor sidedness (P = .41), archival BRAF/MEK/ERK-mutant status (P = .16/1.00/.09), nor baseline ctDNA HER2 amplifications (P = 1.00). CONCLUSION: We identified a 3.2%-6.3% prevalence of the neo-RAS-WT phenomenon in the CO.26 trial. However, 67% of apparent cases were transient with subsequent re-emergence.

Plasma versus Tissue Tumor Mutational Burden as Biomarkers of Durvalumab plus Tremelimumab Response in Patients with Metastatic Colorectal Cancer in the CO.26 Trial.

PURPOSE: Tissue-derived tumor mutation burden (TMB) of ≥10 mutations/Mb is a histology-agnostic biomarker for the immune checkpoint inhibitor (ICI) pembrolizumab. However, the dataset in which this was validated lacked colorectal cancers (CRC), and there is limited evidence for immunotherapy benefits in CRC using this threshold. PATIENTS AND METHODS: CO.26 was a randomized phase II study of 180 patients, comparing durvalumab and tremelimumab (D + T, n = 119 patients) versus best supportive care (BSC; n = 61 patients). ctDNA sequencing was available for 168 patients (n = 118 D + T; n = 50), of whom 165 had evaluable plasma TMB (pTMB). Tissue sequencing was available for 108 patients. Optimal thresholds for stratifying patients based on OS were determined using a minimal P value approach. This report includes the final OS analysis. RESULTS: Tissue TMB ≥10 mutations/Mb was not predictive of benefit from D + T compared with BSC in microsatellite stable (MSS) metastatic CRC [HR, 0.71 (95% CI, 0.28-1.80); P = 0.47]. No tissue TMB threshold could identify a high TMB group that benefited from ICI. By contrast, plasma TMB (pTMB) ≥28 mutations/Mb was predictive of benefit from D + T [HR, 0.34 (95% CI, 0.13-0.85); P = 0.022], as was clonal pTMB ≥10.6 mutations/Mb [HR, 0.10 (95% CI, 0.014-0.79); P = 0.029] and subclonal pTMB ≥25.9/Mb [HR, 0.20 (95% CI, 0.061-0.69); P = 0.010]. Higher pTMB was associated with length of time on cytotoxic agents (P = 0.021) and prior anti-EGFR exposure (P = 2.44 × 10-06). CONCLUSIONS: pTMB derived from either clonal or subclonal mutations may identify a group likely to benefit from immunotherapy, although validation is required. Tissue TMB provided no predictive utility for immunotherapy in this trial.

Management of Locally Advanced Rectal Cancer: ASCO Guideline.

PURPOSE: To provide evidence-based guidance for clinicians who treat patients with locally advanced rectal cancer. METHODS: A systematic review of the literature published from 2013 to 2023 was conducted to identify relevant systematic reviews, phase II and III randomized controlled trials (RCTs), and observational studies where applicable. RESULTS: Twelve RCTs, two systematic reviews, and one nonrandomized study met the inclusion criteria for this systematic review. Expert Panel members used available evidence and informal consensus to develop evidence-based guideline recommendations. RECOMMENDATIONS: Following assessment with magnetic resonance imaging, for patients with microsatellite stable or proficient mismatch repair locally advanced rectal cancer, total neoadjuvant therapy (TNT; ie chemoradiation [CRT] and chemotherapy) should be offered as initial treatment for patients with tumors located in the lower rectum and/or patients who are at higher risk for local and/or distant metastases. Patients without higher-risk factors may discuss chemotherapy with selective CRT depending on extent of response, TNT, or neoadjuvant long-course CRT or short-course radiation. For patients who are candidates for TNT, the preferred timing for chemotherapy is after radiation, and neoadjuvant long-course CRT is preferred over short-course radiation therapy (RT), however short-course RT may also be a viable treatment option depending on circumstances. Nonoperative management may be discussed as an alternative to total mesorectal excision for patients who have a clinical complete response to neoadjuvant therapy. For patients whose tumors are microsatellite instability-high or mismatch repair deficient, immunotherapy is recommended.Additional information is available at http://www.asco.org/gastrointestinal-cancer-guidelines.

Nucleophosmin 1, upregulated in adenomas and cancers of the colon, inhibits p53-mediated cellular senescence.

Dysregulation of nucleophosmin 1 (NPM1) has been found in numerous solid and hematological malignancies. Our previous meta-analysis of colorectal cancer (CRC) high throughput gene expression profiling studies identified it as a consistently reported up-regulated gene in the malignant state. Our aims were to compare NPM1 expression in normal colon, adenoma and CRC, to correlate their expressions with clinico-pathological parameters, and to assess the biological role of aberrant NPM1 expression in CRC cells. NPM1 transcript levels were studied in human CRC cell lines, whereas a tissue microarray of 57 normal human colon, 40 adenoma and 185 CRC samples were used to analyze NPM1 protein expression by immunohistochemistry. CRC cell lines were subjected to transient siRNA-mediated knockdown to study NPM1's roles on cell viability and senescence. NPM1 transcript levels were 7-11-folds higher in three different human CRC cell lines compared to normal colon cells. NPM1 protein expression was found to be progressively and significantly upregulated in CRC compared to adenomas and in adenomas compared to normal mucosa. Reducing NPM1 expression by siRNA had caused a significant decrease in cell viability, a concomitant increase in cellular senescence and cell cycle arrest. Cellular senescence induced under conditions of forced NPM1 suppression could be prevented by knocking down p53. The differential expression of NPM1 along the normal colon-adenoma-carcinoma progression and its involvement in resisting p53 related senescent growth arrest in CRC cell lines implicate its role in supporting CRC tumorigenesis.

Practical considerations when providing palliative care to patients with neuroendocrine tumors in the context of routine disease management or hospice care.

This serves as a white paper by the North American Neuroendocrine Tumor Society (NANETS) on the practical considerations when providing palliative care to patients with neuroendocrine tumors in the context of routine disease management or hospice care. The authors involved in the development of this manuscript represent a multidisciplinary team of patient advocacy, palliative care, and hospice care practitioners, endocrinologist, and oncologists who performed a literature review and provided expert opinion on a series of questions often asked by our patients and patient caregivers affected by this disease. We hope this document serves as a starting point for oncologists, palliative care teams, hospice medical teams, insurers, drug manufacturers, caregivers, and patients to have a frank, well-informed discussion of what a patient needs to maximize the quality of life during a routine, disease-directed care as well as at the end-of-life.

Monitoring and Surveillance of Patients with Gastroenteropancreatic Neuroendocrine Tumors Undergoing Radioligand Therapy.

Radioligand therapy (RLT) with [177Lu]Lu-DOTA-TATE is a standard of care for adult patients with somatostatin-receptor (SSTR)-positive gastroenteropancreatic neuroendocrine tumors (GEP-NETs). Taking advantage of this precision nuclear medicine approach requires diligent monitoring and surveillance, from the use of diagnostic SSTR-targeted radioligand imaging for the selection of patients through treatment and assessments of response. Published evidence-based guidelines assist the multidisciplinary healthcare team by providing acceptable approaches to care; however, the sheer heterogeneity of GEP-NETs can make these frameworks difficult to apply in individual clinical circumstances. There are also contradictions in the literature regarding the utility of novel approaches in monitoring and surveilling patients with GEP-NETs receiving RLT. This article discusses the emerging evidence on imaging, clinical biochemistry, and tumor assessment criteria in the management of patients receiving RLT for GEP-NETs; additionally, it documents our own best practices. This allows us to offer practical guidance on how to effectively implement monitoring and surveillance measures to aid patient-tailored clinical decision-making.

Circulating Tumor DNA Identifies Diverse Landscape of Acquired Resistance to Anti-Epidermal Growth Factor Receptor Therapy in Metastatic Colorectal Cancer.

PURPOSE: Anti-epidermal growth factor receptor (EGFR) antibodies are effective treatments for metastatic colorectal cancer. Improved understanding of acquired resistance mechanisms may facilitate circulating tumor DNA (ctDNA) monitoring, anti-EGFR rechallenge, and combinatorial strategies to delay resistance. METHODS: Patients with treatment-refractory metastatic colorectal cancer (n = 169) enrolled on the CO.26 trial had pre-anti-EGFR tissue whole-exome sequencing (WES) compared with baseline and week 8 ctDNA assessments with the GuardantOMNI assay. Acquired alterations were compared between patients with prior anti-EGFR therapy (n = 66) and those without. Anti-EGFR therapy occurred a median of 111 days before ctDNA assessment. RESULTS: ctDNA identified 12 genes with increased mutation frequency after anti-EGFR therapy, including EGFR (P = .0007), KRAS (P = .0017), LRP1B (P = .0046), ZNF217 (P = .0086), MAP2K1 (P = .018), PIK3CG (P = .018), BRAF (P = .048), and NRAS (P = .048). Acquired mutations appeared as multiple concurrent subclonal alterations, with most showing decay over time. Significant increases in copy-gain frequency were noted in 29 genes after anti-EGFR exposure, with notable alterations including EGFR (P < .0001), SMO (P < .0001), BRAF (P < .0001), MET (P = .0002), FLT3 (P = .0002), NOTCH4 (P = .0006), ERBB2 (P = .004), and FGFR1 (P = .006). Copy gains appeared stable without decay 8 weeks later. There were 13 gene fusions noted among 11 patients, all but one of which was associated with prior anti-EGFR therapy. Polyclonal resistance was common with acquisition of ≥ 10 resistance related alterations noted in 21% of patients with previous anti-EGFR therapy compared with 5% in those without (P = .010). Although tumor mutation burden (TMB) did not differ pretreatment (P = .63), anti-EGFR exposure increased TMB (P = .028), whereas lack of anti-EGFR exposure resulted in declining TMB (P = .014). CONCLUSION: Paired tissue and ctDNA sequencing identified multiple novel mutations, copy gains, and fusions associated with anti-EGFR therapy that frequently co-occur as subclonal alterations in the same patient.