Association of Lateral Pelvic Lymph Nodes with Disease Recurrence and Organ Preservation in Patients with Distal Rectal Adenocarcinoma Treated with Total Neoadjuvant Therapy

OBJECTIVE

Assess the significance of enlarged lateral lymph nodes (LLN) for disease recurrence, metastasis, and organ preservation in patients with rectal cancer.

BACKGROUND

Optimal treatment of rectal adenocarcinoma involving LLN is subject to debate.

METHODS

A post hoc analysis of the OPRA trial, a multicenter study of patients with rectal cancer treated with total neoadjuvant therapy (TNT) followed by total mesorectal excision or watch-and-wait management. We analyzed the association of visible LLN (LLN+), LLN≥7 mm (short axis) on baseline MRI, and LLN≥4 mm on restaging MRI with recurrence, metastasis, and rectum preservation.

RESULTS

At baseline, 57 out of 324 (18%) patients had LLN+. In 30 (53%) of 57 patients with LLN+ on baseline MRI, the LLN disappeared after TNT. Disease recurrence in LLN was rare (3.5% of patients with LLN+ and 0.4% of patients with LLN-). All patients with recurrence in LLN also had distant metastasis. The rate of organ preservation was significantly lower in patients with LLN≥4 mm on restaging MRI (P=0.013). We found no significant differences in rates of local recurrence or metastasis between patients with LLN+ vs. LLN- and in patients with LLN≥7 vs.<7 mm on baseline MRI. LLN dissection was performed in 3 patients; 2 of them died of distant metastasis.

CONCLUSIONS

LLN involvement is not associated with disease recurrence or metastasis, but persistence of LLN≥4 mm after TNT is negatively associated with rectum preservation in patients with locally advanced rectal cancer treated with TNT. Dissection of lateral nodes likely benefits few patients.

Oncologic Outcomes of Salvage Abdominoperineal Resection for Anal Squamous Cell Carcinoma Initially Managed with Chemoradiation

Background: Abdominoperineal resection (APR) has been advocated for persistent or recurrent disease after failure of chemoradiation (CRT) for anal squamous cell cancer (SCC). Treatment with salvage APR can potentially achieve a cure. This study aimed to analyze oncological outcomes for salvage APR in a recent time period at a comprehensive cancer center. Methods: A retrospective review of all patients who underwent APR for biopsy-proven persistent or recurrent anal SCC between 1 January 2007 and 31 December 2020 was performed. Patients with stage IV disease at the time of initial diagnosis and patients with missing data were excluded. Univariate analysis was used with a chi-square test for categorical variables, and non-parametric tests were used for continuous variables. Kaplan-Meier survival analysis was performed to evaluate disease-specific (DSS), post-APR local recurrence-free (RFS), and disease-free survival (DFS). Results: A total of 96 patients were included in the analysis: 39 (41%) with persistent disease and 57 (59%) with recurrent SCC after chemoradiation had been completed. The median follow-up was 22 months (IQR 11-47). Forty-nine patients (51%) underwent extended APR and/or pelvic exenteration. Eight (8%) patients developed local recurrence, 30 (31%) developed local and distant recurrences, and 16 (17%) developed distant recurrences alone. The 3-year DSS, post-APR local recurrence-free survival, and disease-free survival were 53.8% (95% CI 43.5-66.5%), 54.5% (95% CI 44.4-66.8%), and 26.8% (95% CI 18.6-38.7%), respectively. In multivariate logistic regression analysis, positive microscopic margin (OR 10.0, 95% CI 2.16-46.12, p = 0.003), positive nodes in the surgical specimen (OR 9.19, 95% CI 1.99-42.52, p = 0.005), and lymphovascular invasion (OR 2.61 95% CI 1.05-6.51, p = 0.04) were associated with recurrence of disease. Gender, indication for APR (recurrent vs. persistent disease), HIV status, extent of surgery, or type of reconstruction did not influence survival outcomes. Twenty patients had targeted tumor-sequencing data available. Nine patients had PIK3CA mutations, seven of whom experienced a recurrence. Conclusions: Salvage APR for anal SCC after failed CRT was associated with poor disease-specific survival and low recurrence-free survival. Anal SCC patients undergoing salvage APR should be counseled that microscopic positive margins, positive lymph nodes, or the presence of lymphovascular invasion in the APR specimen are prognosticators for disease relapse. Our results accentuate the necessity for additional treatment strategies for the ongoing treatment challenge of persistent or recurrent anal SCC after failed CRT.

Anal Adenocarcinoma Treated in the Era of Total Neoadjuvant Therapy and Nonoperative Management

BACKGROUND

Anal adenocarcinoma bears a treatment strategy unique to other anal cancers.

OBJECTIVE

This study aimed to describe oncologic outcomes of total neoadjuvant therapy followed by watch-and-wait approach for anal adenocarcinoma.

DESIGN

Retrospective analysis.

SETTINGS

This study was conducted at a comprehensive cancer center.

PATIENTS

Patients with anal adenocarcinoma treated between 2004 and 2019 were selected.

INTERVENTIONS

Fifty-four patients received neoadjuvant therapy and were divided into 2 groups according to their treatment strategy: total neoadjuvant therapy versus single neoadjuvant modality therapy.

MAIN OUTCOME MEASURES

Organ preservation, tumor regrowth, local failure, distant metastasis rates, recurrence-free survival, and overall survival.

RESULTS

This study included 70 patients with anal adenocarcinoma. Fifty-four patients (77%) received neoadjuvant therapy, of whom 30 (42%) received total neoadjuvant therapy and 24 (34%) received single neoadjuvant modality. Twenty-three (33%) patients achieved complete clinical response and were managed by watch-and-wait approach. The proportion of patients able to continue to watch-and-wait approach was higher after receiving total neoadjuvant therapy (60%) compared with single neoadjuvant modality therapy (20%; p = 0.004). A tumor regrowth rate of 22% was observed in the total neoadjuvant therapy group. The 5-year overall survival rate was 70% (95% CI, 59%-83%), including 61% (95% CI, 42%-88%) for the total neoadjuvant therapy and 65% (95% CI, 48%-88%) for the single neoadjuvant modality groups. Colostomy was avoided in 50% of patients who received total neoadjuvant therapy and 83% of watch-and-wait patients. Five-year recurrence-free survival rates of 55% (95% CI, 39%-79%) and 30% (95% CI, 15%-58%) were observed in the total neoadjuvant therapy and single neoadjuvant modality groups.

LIMITATIONS

Retrospective nature.

CONCLUSIONS

This is the first report in the literature describing the safety and feasibility of nonoperative management for anal adenocarcinoma. Anal adenocarcinoma treated with total neoadjuvant therapy and nonoperative management achieve regrowth rates comparable to those observed in rectal cancer, with oncologic outcomes similar to those of traditional treatment strategies. See Video Abstract .

ADENOCARCINOMA ANAL TRATADO EN LA ERA DE LA TERAPIA NEOADYUVANTE TOTAL Y EL TRATAMIENTO NO QUIRRGICO

ANTECEDENTES:El adenocarcinoma anal conlleva una estrategia de tratamiento único para otros cánceres anales.OBJETIVO:Describir los resultados oncológicos de la terapia neoadyuvante total seguida de observar y esperar en adenocarcinoma anal.DISEÑO:Análisis retrospectivo.AJUSTE:Este estudio se llevó a cabo en un centro oncológico integral.PACIENTES:Se seleccionaron pacientes con adenocarcinoma anal tratados entre 2004-2019.INTERVENCIONES:Cincuenta y cuatro pacientes recibieron terapia neoadyuvante y se dividieron en dos grupos según su estrategia de tratamiento: terapia neoadyuvante total versus terapia de modalidad neoadyuvante única.PRINCIPALES MEDIDAS DE RESULTADO:Preservación de órganos, recurrencia tumoral, falla local, tasas de metástasis a distancia, libre de recurrencia y supervivencia general.RESULTADOS:El estudio incluyó a 70 pacientes con adenocarcinoma anal. Cincuenta y cuatro pacientes (77%) recibieron terapia neoadyuvante, de los cuales 30 (42%) recibieron terapia neoadyuvante total y 24 (34%) recibieron modalidad neoadyuvante única. Veintitrés (33%) pacientes presentaron una respuesta clínica completa y fueron tratados con vigilancia y espera. La proporción de pacientes capaces de continuar en observar y esperar fue mayor después de recibir terapia neoadyuvante total (60%) en comparación con la terapia de modalidad neoadyuvante única (20%) ( p = 0,004). Se observó una tasa de recurrencia tumoral del 22% en el grupo de terapia neoadyuvante total. La tasa de supervivencia general a 5 años fue del 70% (IC95% 59%-83 %), incluido el 61% (IC95% 42%-88%) para la terapia neoadyuvante total y el 65% (IC95% 48%-88%) para grupos de modalidad neoadyuvante única. Se evitó la colostomía en el 50% de los pacientes que recibieron terapia neoadyuvante total y el 83% de los pacientes en observar y esperar. Se observaron tasas de supervivencia libre de recurrencia a cinco años del 55% (IC95% 39%-79%) y del 30% (IC95% 15%-58%) en los grupos de terapia neoadyuvante total y modalidad neoadyuvante única, respectivamente.LIMITACIONES:Diseño retrospectivo.CONCLUSIONES:Este es el primer informe en la literatura que describe la seguridad y viabilidad del tratamiento no quirúrgico del adenocarcinoma anal. El adenocarcinoma anal tratado con terapia neoadyuvante total y manejo no quirúrgico logra tasas de recurrencia comparables a las observadas en el cáncer de recto, con resultados oncológicos similares a las estrategias de tratamientos tradicionales. (Traducción-Dr. Fidel Ruiz Healy ).

Tumour deposits are independently associated with recurrence in colon cancer

AIM

Tumour deposits are focal aggregates of cancer cells in pericolic fat and mesentery, distinct from vessels, nerves and lymphatics. Their presence upstages lymph node negative patients but is ignored in lymph node positive patients. We investigated the clinicopathological factors associated with tumour deposits and their impact on recurrence in lymph node positive and negative patients.

METHOD

Clinicopathological variables were collected from the medical records of patients with Stage I-III colon cancer who underwent resection in 2017-2019. Pathology was reviewed by a gastrointestinal pathologist. Patients with rectal cancer, metastasis, and concurrent malignancy were excluded.

RESULTS

Tumour deposits were noted in 69 (9%) of 770 patients. They were associated with the presence of lymph node metastasis, advanced T category, poorly differentiated tumours, microsatellite stable subtype and lymphovascular and perineural invasion (p < 0.05). The presence of tumour deposits (hazard ratio 2.48, 95% CI 1.49-4.10) and of lymph node metastasis (hazard ratio 3.04, 95% CI 1.72-5.37) were independently associated with decreased time to recurrence. There was a weak correlation (0.27) between the number of tumour deposits and the number of positive lymph nodes.

CONCLUSION

Tumour deposits are associated with more advanced disease and high-risk pathological features. The presence of tumour deposits and lymph node metastasis were found to be independent risk factors for decreased time to recurrence. A patient with both lymph node metastasis and tumour deposits is more than twice as likely to have recurrence compared with a patient with only lymph node metastasis. Tumour deposits independently predict recurrence and should not be ignored in lymph node positive patients.

Long-Term Results of Organ Preservation in Patients With Rectal Adenocarcinoma Treated With Total Neoadjuvant Therapy: The Randomized Phase II OPRA Trial

Clinical trials frequently include multiple end points that mature at different times. The initial report, typically based on the primary end point, may be published when key planned co-primary or secondary analyses are not yet available. Clinical Trial Updates provide an opportunity to disseminate additional results from studies, published in JCO or elsewhere, for which the primary end point has already been reported.To assess long-term risk of local tumor regrowth, we report updated organ preservation rate and oncologic outcomes of the OPRA trial (ClinicalTrials.gov identifier: NCT02008656). Patients with stage II/III rectal cancer were randomly assigned to receive induction chemotherapy followed by chemoradiation (INCT-CRT) or chemoradiation followed by consolidation chemotherapy (CRT-CNCT). Patients who achieved a complete or near-complete response after finishing treatment were offered watch-and-wait (WW). Total mesorectal excision (TME) was recommended for those who achieved an incomplete response. The primary end point was disease-free survival (DFS). The secondary end point was TME-free survival. In total, 324 patients were randomly assigned (INCT-CRT, n = 158; CRT-CNCT, n = 166). Median follow-up was 5.1 years. The 5-year DFS rates were 71% (95% CI, 64 to 79) and 69% (95% CI, 62 to 77) for INCT-CRT and CRT-CNCT, respectively (P = .68). TME-free survival was 39% (95% CI, 32 to 48) in the INCT-CRT group and 54% (95% CI, 46 to 62) in the CRT-CNCT group (P = .012). Of 81 patients with regrowth, 94% occurred within 2 years and 99% occurred within 3 years. DFS was similar for patients who underwent TME after restaging (64% [95% CI, 53 to 78]) and patients in WW who underwent TME after regrowth (64% [95% CI, 53 to 78]; P = .94). Updated analysis continues to show long-term organ preservation in half of the patients with rectal cancer treated with total neoadjuvant therapy. In patients who enter WW, most cases of tumor regrowth occur in the first 2 years.

Validation of a Clinical Calculator Predicting Freedom From Colon Cancer Recurrence After Surgery on the Basis of Molecular and Clinical Variables

BACKGROUND

The Memorial Sloan Kettering clinical calculator for estimating the likelihood of freedom from colon cancer recurrence on the basis of clinical and molecular variables was developed at a time when testing for microsatellite instability was performed selectively, based on patient age, family history, and histologic features. Microsatellite stability was assumed if no testing was done.

OBJECTIVE

This study aimed to validate the calculator in a cohort of patients who had all been tested for microsatellite instability.

DESIGN

Retrospective cohort analysis.

SETTINGS

Comprehensive cancer center.

PATIENTS

This study included consecutive patients who underwent curative resection for stage I, II, or III colon cancer between 2017 and 2019.

INTERVENTION

Universal testing of mircrosatellite phenotype in all cases.

MAIN OUTCOME MEASURES

The calculator's predictive accuracy was assessed using the concordance index and a calibration plot of predicted versus actual freedom from recurrence at 3 years after surgery. For a secondary sensitivity analysis, the presence of a tumor deposit(s) (disease category N1c) was considered equivalent to one positive lymph node (category N1a).

RESULTS

With a median follow-up of 32 months among survivors, the concordance index for the 745 patients in the cohort was 0.748 (95% CI, 0.693-0.801), and a plot of predicted versus observed recurrences approached the 45° diagonal, indicating good discrimination and calibration. In the secondary sensitivity analysis for tumor deposits, the concordance index was 0.755 (95% CI, 0.700-0.806).

LIMITATIONS

This study was limited by its retrospective, single-institution design.

CONCLUSIONS

These results, based on inclusion of actual rather than imputed microsatellite stability status and presence of tumor deposits, confirm the predictive accuracy and reliability of the calculator. See Video Abstract .

VALIDACIN DE UNA CALCULADORA CLNICA QUE PREDICE LA AUSENCIA DE RECURRENCIA POSTQUIRURGICA DEL CNCER DE COLON SOBRE LA BASE DE VARIABLES MOLECULARES Y CLNICAS

ANTECEDENTES:La calculadora clínica del Memorial Sloan Kettering para la estimación de la probabilidad de ausencia de recurrencia del cáncer de colon sobre la base de variables clínicas y moleculares, se desarrolló en un momento en que las pruebas para la inestabilidad de microsatélites se realizaban de forma selectiva, basadas en la edad del paciente, los antecedentes familiares y las características histológicas. Se asumía la estabilidad micro satelital si no se realizaba ninguna prueba.OBJETIVO:El objetivo de este estudio fue validar la calculadora en una cohorte de pacientes a los que se les había realizado la prueba de inestabilidad de microsatélites.DISEÑO:Análisis de cohorte retrospectivo.AJUSTE:Centro integral de cáncer.PACIENTES:Pacientes consecutivos con cáncer de colon que fueron sometidos a resección curativa por cáncer de colon en estadios I, II o III entre los años 2017 y 2019.PRINCIPALES MEDIDAS DE RESULTADO:La precisión predictiva de la calculadora fue evaluada mediante el índice de concordancia y un gráfico de calibración de la ausencia de recurrencia predecida versus la real a los 3 años tras la cirugía. A los efectos de un análisis secundario de sensibilidad, la presencia de depósito(s) tumoral(es) (categoría de enfermedad N1c) se consideró equivalente a un ganglio linfático positivo (categoría N1a).RESULTADOS:Con una mediana de seguimiento de 32 meses entre los supervivientes, el índice de concordancia para los 745 pacientes de la cohorte fue de 0,748 (intervalo de confianza del 95 %, 0,693 a 0,801), y una gráfica de recurrencias previstas versus observadas se acercó a la diagonal de 45°, indicando una buena discriminación y calibración. En el análisis secundario de sensibilidad para depósitos tumorales, el índice de concordancia fue de 0,755 (intervalo de confianza del 95 %, 0,700 a 0,806).LIMITACIONES:Diseño retrospectivo, institución única.CONCLUSIONES:Estos resultados, basados en la inclusión real del estado de estabilidad de microsatélites en lugar de imputado y la presencia de depósitos tumorales, confirman la precisión predictiva y la confiabilidad de la calculadora. (Traducción-Dr Osvaldo Gauto ).

Nonoperative management of the primary tumor in patients with unresectable stage IV colon cancer treated with systemic chemotherapy: Higher complication rates for left-sided colon tumors

INTRODUCTION

Treatment of the primary tumor in asymptomatic patients with unresectable colorectal metastases remains controversial.

METHODS

Data from patients with synchronous stage IV colon cancer and an untreated primary tumor who started treatment aimed at metastatic disease at a specialized cancer center between 2014 and 2018 were analyzed retrospectively. Main outcome was primary tumor-related complications comparing left-sided and right-sided colon cancer. A competing-risk regression model was used to identify predictors of complications.

RESULTS

Of 523 patients with metastatic colon cancer at presentation, 221 started treatment aimed at metastatic disease; these patients constituted the study cohort. The primary tumor was left-sided in 109 patients (49%) and right-sided in 112 patients (51%). In total, 46 patients (21%) developed a complication that required invasive intervention. Complications occurred more frequently in patients with left-sided tumors than in patients with right-sided tumors (29% vs 13%, P = 0.003). Eighteen patients (8%) underwent non-surgical intervention. Six patients (33%) failed non-surgical management and underwent surgery. Of 34 patients (15%) who underwent surgical intervention, 20 underwent an emergency colectomy and 14 underwent diversion with a permanent stoma. Overall, 10% of patients ended up with a permanent stoma. In competing-risk analysis, only left-sided primary tumor (hazard ratio 2.62; 95% CI 1.40-4.89; P = 0.003) was significantly associated with primary tumor-related complications requiring invasive intervention.

CONCLUSIONS

Patients with asymptomatic metastatic left-sided tumors have a higher risk for primary tumor-related complications than patients with right-sided tumors. Close monitoring and early surgical rescue should be considered for patients with left-sided colon cancer who are managed nonoperatively.

Lymph Node Metastases and Associated Recurrence-Free Survival in Microsatellite Stable and Unstable Colon Cancer

BACKGROUND

In contrast to microsatellite stable (MSS) colon cancer, predictors of lymph node metastases and their association with recurrence are not well-defined in microsatellite instability (MSI) colon cancer.

METHODS

A cohort of nonmetastatic colon cancer patients undergoing surgery between 2015 and 2021 were evaluated for predictors of lymph node metastases (LNMs) and their association with recurrence-free survival (RFS).

RESULTS

Of 1466 patients included in the analyses, 361 (25 %) had MSI. Compared with MSS, MSI was associated with earlier stage, fewer LNMs in the patients with N1 or N2 disease, and fewer high-risk features. Compared with the T3-T4 MSS patients, the odds ratios for LNM were 0.52 (95% confidence interval [CI], 0.38-0.71) for the T3-T4 MSI patients, 0.27 (95% CI, 0.38-0.71) for the T1-T2 MSS patients, and 0.15 (95 % CI, 0.08-0.26) for the T1-T2 MSI patients. In both groups, LNMs were associated with T category, patient age, and venous, lymphatic, or perineural invasion. In the MSS patients, LNMs were additionally associated with patient sex and histologic grade. Compared with the MSS patients, the MSI patients with N0 and N1 disease had a better 3-year RFS. However, the MSI patients with N2 disease had a lower rate of 3-year RFS than the MSS patients (hazard ratio, 19.75 vs 4.49).

CONCLUSIONS

In MSI colon cancer, LNMs are 50 % less prevalent, but the factors associated with LNM are like those in MSS colon cancer. The improved prognosis traditionally associated with early-stage MSI colon cancers dissipates with four or more LNMs. These findings should be taken into consideration by clinicians selecting the most appropriate course of treatment for MSI colon cancer.

Comparison of Robotic, Laparoscopic, and Open Resections of Nonmetastatic Colon Cancer

BACKGROUND

Laparoscopic resection for colon cancer has not been associated with improvements in oncological outcomes in comparison to open resection. Robotic resections are associated with increased lymph node yield and radicality of mesenteric resection in patients with right-sided tumors. It is unclear whether lymph node yield is higher in robotic resections in other parts of the colon and whether higher lymph node yield is associated with improved survival.

OBJECTIVE

To compare survival rates between robotic, laparoscopic, and open resections in a large cohort of patients with nonmetastatic colon cancer.

DESIGN

This is a retrospective observational study.

SETTING

A single comprehensive cancer center.

PATIENTS

Patients who underwent resection of nonmetastatic primary colon cancer between January 2006 and December 2018.

MAIN OUTCOME MEASURES

Univariable and multivariable models were used to identify predictors of disease-free and overall survival. Lymph node yield and perioperative outcomes were compared between operative approaches.

RESULTS

There were 2398 patients who met the inclusion criteria: 699 (29%) underwent open, 824 (34%) underwent laparoscopic, and 875 (36%) underwent robotic resection. The median follow-up was 3.8 years (45.4 months). Robotic surgery was associated with higher lymph node yield and radicality of mesenteric resection. On multivariable analysis, the surgical approach was not associated with a difference in disease-free or overall survival. Minimally invasive colectomy was associated with fewer complications and shorter length of stay in comparison to open surgery. In a direct comparison between the 2 minimally invasive approaches, robotic colectomy was associated with fewer complications, shorter length of stay, and lower conversion rate than laparoscopy.

LIMITATIONS

This was a single-center retrospective study.

CONCLUSIONS

Our data indicate that the 3 surgical approaches are similarly effective in treating primary resectable colon cancer and that differences in outcomes are observed primarily in the early postoperative period. See Video Abstract at http://links.lww.com/DCR/C115 .

COMPARACIN DE RESECCIONES ROBTICAS, LAPAROSCPICAS Y ABIERTAS DE CNCER DE COLON NO METASTSICO

ANTECEDENTES:La resección laparoscópica para el cáncer de colon no se ha asociado con mejoras en los resultados oncológicos en comparación con la resección abierta. Las resecciones robóticas se asocian con un mayor rendimiento de los ganglios linfáticos y la radicalidad de la resección mesentérica en pacientes con tumores del lado derecho. No está claro si la cosecha ganglionar es mayor en las resecciones robóticas en otras partes del colon y si un mayor rendimiento de los ganglios linfáticos se asocia con una mejor supervivencia.OBJETIVO:Comparar las tasas de supervivencia entre resecciones robóticas, laparoscópicas y abiertas en una gran cohorte de pacientes con cáncer de colon no metastásico.DISEÑO:Este es un estudio observacional retrospectivo.ESCENARIO:Este estudio se realizó en un único centro oncológico integral.PACIENTES:Pacientes que se sometieron a resección de cáncer de colon primario no metastásico entre enero de 2006 y diciembre de 2018.PRINCIPALES MEDIDAS DE RESULTADO:Se utilizaron modelos univariables y multivariables para identificar predictores de supervivencia libre de enfermedad y global. La cosecha ganglionar y los resultados perioperatorios se compararon entre los abordajes quirúrgicos.RESULTADOS:Hubo 2398 pacientes que cumplieron con los criterios de inclusión: 699 (29%) se sometieron a cirugía abierta, 824 (34%) se sometieron a resección laparoscópica y 875 (36%) se sometieron a resección robótica. La mediana de seguimiento fue de 3,8 años (45,4 meses). La cirugía robótica se asoció con una mayor cosecha ganglionar y la radicalidad de la resección mesentérica. En el análisis multivariable, el abordaje quirúrgico no se asoció con una diferencia en la supervivencia general o libre de enfermedad. La colectomía mínimamente invasiva se asoció con menos complicaciones y una estancia más corta en comparación con la cirugía abierta. En una comparación directa entre los dos enfoques mínimamente invasivos, la colectomía robótica se asoció con menos complicaciones, una estancia más corta y una tasa de conversión más baja que la laparoscopia.LIMITACIONES:Este fue un estudio retrospectivo de un solo centro.CONCLUSIONES:Nuestros datos indican que los tres enfoques quirúrgicos son igualmente efectivos en el tratamiento del cáncer de colon resecable primario y que las diferencias en los resultados se observan principalmente en el período posoperatorio temprano. Consulte Video Resumen en http://links.lww.com/DCR/C115 . (Traducción-Dr. Felipe Bellolio ).

Perioperative Team-Based Morbidity and Mortality Conferences: A Systematic Review of the Literature

Objective

This systematic review aimed to identify key elements of perioperative team-based morbidity and mortality conferences (TBMMs) and their impact on patient safety, education, and quality improvement outcomes.

Background

Patient safety in the perioperative period is influenced by system, team, and individual behaviors. However, despite this recognition, single-discipline morbidity and mortality conferences remain a mainstay of educational and quality improvement efforts.

Methods

A structured search was conducted in MEDLINE Complete, Embase, Web of Science, ClinicalTrials.gov, Cochrane CENTRAL, and ProQuest Dissertations and Theses Global in July 2022. Search results were screened, and the articles meeting inclusion criteria were abstracted.

Results

Seven studies were identified. Key TBMM elements were identified, including activities done before the conference-case selection and case investigation; during the conference-standardized presentation formats and formal moderators; and after the conference-follow-up emails and quality improvement projects. The impacts of TBMMs on educational, safety, and quality improvement outcomes were heterogeneous, and no meta-analysis could be conducted; however, improvement was typically shown in each of these domains where comparisons were made.

Conclusions

Recommendations for key TBMM elements can be drawn from the reports of successful perioperative TBMMs. Possible benefits of structured TBMMs over single-discipline conferences were identified for further exploration, including opportunities for rich educational contributions for trainees, improved patient safety, and the potential for system-wide quality improvement. Design and implementation of TBMM should address meticulous preparation of cases, standardized presentation format, and effective facilitation to increase the likelihood of realizing the potential benefits.

Efficacy of HER2-Targeted Intraperitoneal 225Ac α-Pretargeted Radioimmunotherapy for Small-Volume Ovarian Peritoneal Carcinomatosis

Epithelial ovarian cancer (EOC) is often asymptomatic and presents clinically in an advanced stage as widespread peritoneal microscopic disease that is generally considered to be surgically incurable. Targeted α-therapy with the α-particle-emitting radionuclide 225Ac (half-life, 9.92 d) is a high-linear-energy-transfer treatment approach effective for small-volume disease and even single cells. Here, we report the use of human epidermal growth factor receptor 2 (HER2) 225Ac-pretargeted radioimmunotherapy (PRIT) to treat a mouse model of human EOC SKOV3 xenografts growing as peritoneal carcinomatosis (PC). Methods: On day 0, 105 SKOV3 cells transduced with a luciferase reporter gene were implanted intraperitoneally in nude mice, and tumor engraftment was verified by bioluminescent imaging (BLI). On day 15, treatment was started using 1 or 2 cycles of 3-step anti-HER2 225Ac-PRIT (37 kBq/cycle as 225Ac-Proteus DOTA), separated by a 1-wk interval. Efficacy and toxicity were monitored for up to 154 d. Results: Untreated PC-tumor-bearing nude mice showed a median survival of 112 d. We used 2 independent measures of response to evaluate the efficacy of 225Ac-PRIT. First, a greater proportion of the treated mice (9/10 1-cycle and 8/10 2-cycle; total, 17/20; 85%) survived long-term compared with controls (9/27, 33%), and significantly prolonged survival was documented (log-rank [Mantel-Cox] P = 0.0042). Second, using BLI, a significant difference in the integrated BLI signal area to 98 d was noted between controls and treated groups (P = 0.0354). Of a total of 8 mice from the 2-cycle treatment group (74 kBq total) that were evaluated by necropsy, kidney radiotoxicity was mild and did not manifest itself clinically (normal serum blood urea nitrogen and creatinine). Dosimetry estimates (relative biological effectiveness-weighted dose, where relative biological effectiveness = 5) per 37 kBq administered for tumors and kidneys were 56.9 and 16.1 Gy, respectively. One-cycle and 2-cycle treatments were equally effective. With immunohistology, mild tubular changes attributable to α-toxicity were observed in both therapeutic groups. Conclusion: Treatment of EOC PC-tumor-bearing mice with anti-HER2 225Ac-PRIT resulted in histologic cures and prolonged survival with minimal toxicity. Targeted α-therapy using the anti-HER2 225Ac-PRIT system is a potential treatment for otherwise incurable EOC.

Comparison of short-term outcomes and survival between minimally invasive colectomy and open colectomy in patients 80 years of age and older

We investigated the short- and long-term outcomes of patients 80 years of age and older with colon cancer who underwent robotic colectomy versus laparoscopic colectomy. Data for patients treated at a comprehensive cancer center between January 2006 and November 2018 were collected retrospectively. Outcomes from minimally invasive laparoscopic or robotic colectomy were compared. Survival was analyzed by the Kaplan-Meier method with significance evaluated by the log-rank test. The laparoscopic (n = 104) and the robotic (n = 75) colectomy groups did not differ across baseline characteristics. Patients who underwent a robotic colectomy had a shorter median length of hospital stay (5 versus 6 days; p < 0.001) and underwent fewer conversions to open surgery (3% versus 17%; p = 0.002) compared to the laparoscopic cohort. The groups did not differ in postoperative complication rates, overall survival or disease-free survival. Elderly patients undergoing robotic colectomy for colon cancer have a shorter hospital stay and lower rates of conversion without compromise to oncologic outcomes.

The Impact of Germline Alterations in Appendiceal Adenocarcinoma

PURPOSE

More than 10% of assessed patients with appendiceal adenocarcinoma have a pathogenic (P) or likely pathogenic (LP) germline variant, including genes implicated in heritable gastrointestinal cancer syndromes, such as Lynch syndrome. We defined the clinical and molecular impact of heritable alterations in appendiceal adenocarcinoma to evaluate the need for dedicated appendiceal screening and prevention strategies in patients with LP/P germline variants.

EXPERIMENTAL DESIGN

We performed an integrated germline and somatic molecular analysis for patients with confirmed appendiceal adenocarcinoma. Patients underwent paired tumor-normal sequencing for up to 90 hereditary cancer risk genes and 505 genes for somatic mutation profiling. We defined the cooccurrence of LP/P germline variants and second-hit pathogenic somatic alterations. The associations between germline variants and patient clinicopathologic features were also evaluated.

RESULTS

Twenty-five of 237 patients (10.5%) carried pathogenic or likely pathogenic germline variants in cancer susceptibility genes. Clinicopathologic characteristics and appendiceal adenocarcinoma-specific survival were similar in patients with or without germline variants. Most (92%, N = 23/25) patients with germline variants demonstrated no second-hit somatic alterations, including loss of heterozygosity. Two patients with a germline APC I1307K low-penetrance founder variant exhibited secondary somatic pathogenic alterations in APC. However, only one patient tumor exhibited APC-mediated WNT signaling dysregulation: a plausible consequence of multiple somatic APC mutations with no germline variant contribution. Four patients had germline variants in PMS2 or MSH2 associated with Lynch syndrome, yet their cancers were microsatellite-stable.

CONCLUSIONS

Germline variants are likely incidental without a contributory driver role in appendiceal adenocarcinoma. Appendiceal adenocarcinoma screening in patients with germline variants is not clearly merited.

MRI Assessment of Extramural Venous Invasion Before and After Total Neoadjuvant Therapy for Locally Advanced Rectal Cancer and Its Association with Disease-Free and Overall Survival

BACKGROUND

Extramural venous invasion (EMVI) on baseline MRI is associated with poor prognosis in patients with locally advanced rectal cancer. This study investigated the association of persistent EMVI after total neoadjuvant therapy (TNT) (chemoradiotherapy and systemic chemotherapy) with survival.

METHODS

Baseline MRI, post-TNT MRI, and surgical pathology data from 175 patients with locally advanced rectal cancer who underwent TNT and total mesorectal excision between 2010 and 2017 were retrospectively analyzed for evidence of EMVI. Two radiologists assessed EMVI status with disagreement adjudicated by a third. Pathologic EMVI status was assessed per departmental standards. Cox regression models evaluated the associations between EMVI and disease-free and overall survival.

RESULTS

EMVI regression on both post-TNT MRI and surgical pathology was associated with disease-free survival (hazard ratio, 0.17; 95% confidence interval (CI), 0.04-0.64) and overall survival (hazard ratio, 0.11; 95% CI, 0.02-0.68). In an exploratory analysis of 35 patients with EMVI on baseline MRI, only six had EMVI on pathology compared with 18 on post-TNT MRI; these findings were not associated (p = 0.2). Longer disease-free survival was seen with regression on both modalities compared with remaining positive. Regression on pathology alone, independent of MRI EMVI status, was associated with similar improvements in survival.

CONCLUSIONS

Baseline EMVI is associated with poor prognosis even after TNT. EMVI regression on surgical pathology is common even with persistent EMVI on post-TNT MRI. EMVI regression on surgical pathology is associated with improved DFS, while the utility of post-TNT MRI EMVI persistence for decision-making and prognosis remains unclear.

Incomplete cytoreductive surgery for appendiceal and colorectal peritoneal carcinomatosis: Characteristics and outcomes of an overlooked group

BACKGROUND OND OBJECTIVES

Complete cytoreductive surgery (CRS) may prolong survival for selected patients with peritoneal carcinomatosis from colorectal cancer (CRC). However, there is a paucity of data on outcomes following incomplete procedures.

METHODS

Patients with incomplete CRS for well-differentiated (WD) and moderate/poorly-differentiated (M/PD) appendiceal cancer, right and left CRC were identified at a single tertiary center (2008-2021).

RESULTS

Of 109 patients, 10% were WD and 51% M/PD appendiceal cancers, and 16% right and 23% left CRC. There were no differences in gender, BMI (mean = 27), ASA score, previous abdominal surgery (72%), and extent of CRS. The PC Index differed between appendiceal and colorectal cancers (mean = 27 vs. 17, p < 0.01). Overall, the perioperative outcomes were similar among the groups, with 15% experiencing complications. Postoperatively, 61% received chemotherapy, and 51% required ≥1 subsequent procedure. The 1 and 3-year survival for the WD, M/PD, right and left CRC subgroups were 100%, 67%, 44%, 51%, and 88%, 17%, 12%, and 23%, respectively (p = 0.02).

CONCLUSIONS

Incomplete CRS was associated with significant morbidity and number of subsequent palliative procedures. Prognosis correlated with histologic subtype; WD appendiceal cancer patients having superior outcomes, while those with right sided CRC the worst survival. These data may help guiding expectations in the setting of incomplete procedures.

Molecular Classification of Appendiceal Adenocarcinoma

PURPOSE

Appendiceal adenocarcinomas (ACs) are rare, histologically diverse malignancies treated as colorectal cancers despite having distinct biology and clinical behavior. To guide clinical decision making, we defined molecular subtypes of AC associated with patient survival, metastatic burden, and chemotherapy response.

PATIENTS AND METHODS

A comprehensive molecular analysis was performed in patients with AC to define molecular subtypes. Associations between molecular subtype and overall survival, intraoperative peritoneal cancer index, and first-line chemotherapy response were assessed adjusting for histopathologic and clinical variables using multivariable Cox proportional hazards, linear regression, and logistic regression models.

RESULTS

We defined distinct molecular lineages of mucinous appendiceal adenocarcinoma (MAAP) from co-occurring mutations in GNAS, RAS, and TP53. Of 164 MAAP tumors, 24 were RAS-mutant (mut) predominant (RAS-mut/GNAS-wild-type [wt]/TP53-wt) with significantly decreased mutations and chromosomal alterations compared with tumors with GNAS mutations (GNAS-mut predominant) or TP53 mutations (TP53-mut predominant). No patient with RAS-mut predominant subtype metastatic MAAP died of cancer, and overall survival in this subgroup was significantly improved compared with patients with GNAS-mut (P = .05) and TP53-mut (P = .004) predominant subtypes. TP53-mut predominant subtypes were highly aneuploid; increased tumor aneuploidy was independently (P = .001) associated with poor prognosis. The findings retained significance in patients with any metastatic AC. RAS-mut predominant metastases exhibited reduced peritoneal tumor bulk (P = .04) and stromal invasion (P < .001) compared with GNAS-mut or TP53-mut predominant tumors, respectively. Patients with RAS-mut predominant MAAP responded more to first-line chemotherapy (50%) compared with patients with GNAS-mut predominant tumors (6%, P = .03).

CONCLUSION

AC molecular patterns identify distinct molecular subtypes: a clinically indolent RAS-mut/GNAS-wt/TP53-wt subtype; a chemotherapy-resistant GNAS-mut predominant subtype; and an aggressive, highly aneuploid TP53-mut predominant subtype. Each subtype exhibits conserved clinical behavior irrespective of histopathology.

Assessment of Patient-Reported Outcomes in Patients With Anal Squamous-Cell Cancer Undergoing Combined Modality Therapy

BACKGROUND

There is limited knowledge on long-term bowel, sexual, and urinary function after combined modality therapy for anal squamous-cell cancer.

OBJECTIVE

This study aimed to evaluate long-term changes in patients treated with combined modality.

DESIGN

This was a retrospective study of prospectively collected patient-reported outcome surveys.

SETTING

This study was conducted at a single institution.

PATIENTS

There were 143 patients with stage I to III anal cancer who were treated with chemoradiation and had completed the survey.

MAIN OUTCOME MEASURES

This study included patient-reported outcomes reflecting bowel, sexual, and urinary function.

RESULTS

Thirty-nine percent of patients had major low anterior resection syndrome at baseline. Major low anterior resection syndrome remained stable (38%; 95% CI, 31%-46%) with no change over time (OR 0.95; 95% CI, 0.74-1.21; p = 0.7). Higher rates of major low anterior resection syndrome were observed for patients who had major low anterior resection syndrome at baseline (OR 20.7; 95% CI 4.70-91.3; p < 0.001) and for females (OR 2.14; 95% CI, 1.01-4.56; p = 0.047). On 5-point scales, we saw a nonsignificant increased level of sexual arousal during sexual activity after therapy for women (β for 1 year = 0.15; 95% CI, -0.01 to 0.32; p = 0.072) and nonsignificant decreased confidence in getting and keeping an erection after therapy for men (β for 1 year = -0.33; 95% CI, -0.66 to 0.00; p = 0.053).

LIMITATIONS

This was a single-institution study and only patients who answered the questionnaire were included in the study.

CONCLUSIONS

A significant proportion of patients have major low anterior resection syndrome at baseline and after successful treatment for anal cancer. Having major low anterior resection syndrome at baseline was the biggest predictor of having major low anterior resection syndrome after treatment. Bowel, sexual, and urinary function did not improve over time up to 2 years after end of treatment. Physicians should counsel their patients before treatment that baseline poor bowel function is a risk factor for posttreatment bowel dysfunction. See Video Abstract at http://links.lww.com/DCR/C29 .

EVALUACIN DE LOS RESULTADOS INFORMADOS POR LOS PACIENTES CON CNCER ANAL DE CLULAS ESCAMOSAS QUE SE SOMETEN A UNA TERAPIA DE MODALIDAD COMBINADA

ANTECEDENTES:Existe un conocimiento limitado sobre la función intestinal, sexual y urinaria a largo plazo después de la terapia de modalidad combinada para el cáncer anal de células escamosas.OBJETIVO:Evaluar los cambios a largo plazo en la función intestinal, sexual y urinaria en pacientes tratados con modalidad combinada.DISEÑO:Este fue un estudio retrospectivo de encuestas de resultados informadas por pacientes recolectadas prospectivamente.ESCENARIO:Institución única.PACIENTES:Fueron 143 pacientes con cáncer anal en estadio I-III que fueron tratados con quimiorradiación y completaron la encuesta.PRINCIPALES MEDIDAS DE RESULTADO:Resultados reportados por el paciente que reflejan la función intestinal, sexual, y urinaria.RESULTADOS:Treinta y nueve por ciento de los pacientes tenían puntajes importantes de síndrome de resección anterior bajo al inicio del estudio. Las puntuaciones del síndrome de resección anterior baja mayor permanecieron estables (38 %; IC del 95%: 31 %, 46 %) sin cambios con el tiempo (OR 0,95, IC del 95%: 0,74, 1,21, p = 0,7). Se observaron tasas más altas de puntuaciones del síndrome de resección anterior baja mayor para los pacientes que tenían puntuaciones del síndrome de resección anterior baja mayor desde el inicio (OR 20,7; IC del 95%: 4,70; 91,3, p < 0,001) y para las mujeres (OR 2,14; IC del 95%: 1,01, 4,56; p = 0,047). En escalas de 5 puntos, observamos un aumento no significativo del nivel de excitación sexual durante la actividad sexual después de la terapia para las mujeres (β durante 1 año = 0,15; IC del 95%: -0,01, 0,32; p = 0,072) y una disminución no significativa de la confianza en lograr y mantener una erección después de la terapia para hombres (β para 1 año = -0,33; IC del 95%: -0,66, 0,00; p = 0,053).LIMITACIONES:Este es un estudio de una sola institución. Solo se incluyeron en el estudio los pacientes que contestaron el cuestionario.CONCLUSIONES:Una proporción significativa de pacientes tienen puntajes de síndrome de resección anterior muy bajos al inicio del estudio y después de un tratamiento exitoso para el cáncer anal. Tener puntajes de síndrome de resección anterior bajos importantes al inicio del estudio fue el predictor más importante de tener puntajes de síndrome de resección anterior bajos importantes después del tratamiento. La función intestinal, sexual y urinaria no mejoró con el tiempo hasta 2 años después de finalizar el tratamiento. Los médicos deben aconsejar a sus pacientes antes del tratamiento que la mala función intestinal inicial es un factor de riesgo para la disfunción intestinal posterior al tratamiento. Consulte Video Resumen en http://links.lww.com/DCR/C29 . (Traducción-Dr. Yolanda Colorado ).

Predictors of operative difficulty in robotic low anterior resection for rectal cancer

AIM

This study evaluates the relationship of tumour and anatomical features with operative difficulty in robotic low anterior resection performed by four experienced surgeons in a high-volume colorectal cancer practice.

METHODS

Data from 382 patients who underwent robotic low anterior resection by four expert surgeons between January 2016 and June 2019 were included in the analysis. Operating time was used as a measure of operative difficulty. Univariate and multivariate mixed models were used to identify associations between baseline characteristics and operating time, with surgeon as a random effect, thereby controlling for variability in surgeon speed and proficiency. In an exploratory analysis, operative difficulty was defined as conversion to laparotomy, a positive margin or an incomplete mesorectum.

RESULTS

Median operating time was 4.28 h (range 1.95-11.33 h) but varied by surgeon from 3.45 h (1.95-6.10 h) to 5.93 h (3.33-11.33 h) (P < 0.001). Predictors of longer operating time in multivariate analysis were male sex, higher body mass index, neoadjuvant radiotherapy, low tumour height, greater sacral height and larger mesorectal area at the S5 vertebral level. Conversion occurred in two cases (0.5%), and incomplete mesorectum and positive margins were found in nine (2.4%) and 19 (5.0%) patients, respectively. Neoadjuvant radiotherapy and larger pelvic outlet were the only characteristics associated with the exploratory measure of difficulty.

CONCLUSION

Predicting operative difficulty based on easy to identify, preoperative radiological and clinical variables is feasible in robotic anterior resection.

Quality of life and function after rectal cancer surgery with and without sphincter preservation

Despite improvements in surgical techniques, functional outcomes and quality of life after therapy for rectal cancer remain suboptimal. We sought to prospectively evaluate the effect of bowel, bladder, and sexual functional outcomes on health-related quality of life (QOL) in patients with restorative versus non-restorative resections after rectal cancer surgery. A cohort of 211 patients with clinical stage I-III rectal cancer who underwent open surgery between 2006 and 2009 at Memorial Sloan Kettering were included. Subjects were asked to complete surveys preoperatively and at 6, 12, and 24 months after surgery. Validated instruments were used to measure QOL, bowel, bladder, and sexual function. Univariable and multivariable regression analyses evaluated predictors of 24- month QOL. In addition, longitudinal trends over the study period were evaluated using repeated measures models. In total, 180 patients (85%) completed at least 1 survey, and response rates at each time point were high (>70%). QOL was most impaired at 6 and 12 months and returned to baseline levels at 24 months. Among patients who underwent sphincter-preserving surgery (SPS; n=153 [85%]), overall bowel function at 24 months was significantly impaired and never returned to baseline. There were no differences in QOL at 24 months between patients who underwent SPS and those who did not (p=.29). Bowel function was correlated with QOL at 24 months (Pearson correlation,.41; p<.001). QOL among patients who have undergone SPS for rectal cancer is good despite poor function. Patients with ostomies are able to adjust to the functional changes and, overall, have good global QOL. Patients with low anastomoses had lower global QOL at 24 months than patients with permanent stomas. Our findings can help patients set expectations about function and quality of life after surgery for rectal cancer with and without a permanent stoma.

EWSR1::YY1 fusion positive peritoneal epithelioid mesothelioma harbors mesothelioma epigenetic signature: Report of 3 cases in support of an emerging entity

Mesothelioma is a rare, aggressive malignant neoplasm of mesothelial origin. A small subset of peritoneal mesothelioma is driven by recurrent gene fusions, mostly EWSR1/FUS::ATF1 fusions, with predilection for young adults. To date, only two cases of mesothelioma harboring EWSR1::YY1 fusions have been described. We present three additional cases of EWSR1::YY1-fused peritoneal mesotheliomas, two localized and one diffuse, all occurring in the peritoneum of middle-aged adults (2 females and 1 male), and discovered incidentally by imaging or during surgery performed for unrelated reasons. None presented with symptoms or had a known history of asbestos exposure. All three cases were cellular epithelioid neoplasms with heterogeneous architectural patterns comprising mostly solid nests and sheets with variably papillary and trabecular areas against collagenous stroma. Cytologically, the cells were monomorphic, polygonal, epithelioid cells with dense eosinophilic cytoplasm and centrally located nuclei. Overt mitotic activity or tumor necrosis was absent. All cases showed strong diffuse immunoreactivity for pancytokeratin, CK7, and nuclear WT1, patchy to negative calretinin, retained BAP1 expression, and were negative for Ber-EP4 and MOC31. RNA-sequencing confirmed in-frame gene fusion transcripts involving EWSR1 exon 7/8 and YY1 exon 2/3. By unsupervised clustering analysis, the methylation profiles of EWSR1::YY1-fused mesotheliomas clustered similarly with EWSR1/FUS::ATF1-fused mesotheliomas and conventional mesotheliomas, suggesting a mesothelioma epigenetic signature. All three patients underwent surgical resection or cytoreductive surgery of the masses. On follow-up imaging, no recurrence or progression of disease was identified. Our findings suggest that EWSR1::YY1-fusion defines a small subset of peritoneal epithelioid mesothelioma in middle-aged adults without history of asbestos exposure.

A Dynamic Clinical Calculator for Estimating Conditional Recurrence-Free Survival After Total Neoadjuvant Therapy for Rectal Cancer and Either Surgery or Watch-and-Wait Management

IMPORTANCE

The risk of recurrence in patients with locally advanced rectal cancer has historically been determined after surgery, relying on pathologic variables. A growing number of patients are being treated without surgery, and their risk of recurrence needs to be calculated differently.

OBJECTIVE

To develop a dynamic calculator for estimating the probability of recurrence-free survival (RFS) in patients with rectal cancer who undergo total neoadjuvant therapy (TNT) (induction systemic chemotherapy and chemoradiotherapy) and either surgery or watch-and-wait management.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study included patients who presented with stage II or III rectal cancer between June 1, 2009, and March 1, 2015, at a comprehensive cancer center. Conditional modeling was incorporated into a previously validated clinical calculator to allow the probability of RFS to be updated based on whether the patient remained in watch-and-wait management or underwent delayed surgery. Data were analyzed from November 2021 to March 2022.

EXPOSURE

TNT followed by immediate surgery or watch-and-wait management with the possibility of delayed surgery.

MAIN OUTCOMES AND MEASURES

RFS, concordance index, calibration curves.

RESULTS

Of the 302 patients in the cohort, 204 (68%) underwent surgery within 3 months from TNT completion (median [range] age, 51 [22-82] years; 78 [38%] women), 54 (18%) underwent surgery more than 3 months from TNT completion (ie, delayed surgery; median [range] age, 62 [31-87] years; 30 [56%] female), and 44 (14%) remained in watch-and-wait management as of April 21, 2021 (median [range] age, 58 [32-89] years; 16 [36%] women). Among patients who initially opted for watch-and-wait management, migration to surgery due to regrowth or patient choice occurred mostly within the first year following completion of TNT, and RFS did not differ significantly whether surgery was performed 3.0 to 5.9 months (73%; 95% CI, 52%-92%) vs 6.0 to 11.9 months (71%; 95% CI, 51%-99%) vs more than 12.0 months (70%; 95% CI, 49%-100%) from TNT completion (P = .70). RFS for patients in the watch-and-wait cohort at 12 months from completion of TNT more closely resembled patients who had undergone surgery and had a pathologic complete response than the watch-and-wait cohort at 3 months from completion of TNT. Accordingly, model performance improved over time, and the concordance index increased from 0.62 (95% CI, 0.53-0.71) at 3 months after TNT to 0.66 (95% CI, 0-0.75) at 12 months.

CONCLUSIONS AND RELEVANCE

In this cohort study of patients with rectal cancer, the clinical calculator reliably estimated the likelihood of RFS for patients who underwent surgery immediately after TNT, patients who underwent delayed surgery after entering watch-and-wait management, and patients who remained in watch-and-wait management. Delayed surgery following attempted watch-and-wait did not appear to compromise oncologic outcomes. The risk calculator provided conditional survival estimates at any time during surveillance and could help physicians counsel patients with rectal cancer about the consequences of alternative treatment pathways and thereby support informed decisions that incorporate patients' preferences.

Organ Preservation in Patients With Rectal Adenocarcinoma Treated With Total Neoadjuvant Therapy

PURPOSE

Prospective data on the efficacy of a watch-and-wait strategy to achieve organ preservation in patients with locally advanced rectal cancer treated with total neoadjuvant therapy are limited.

METHODS

In this prospective, randomized phase II trial, we assessed the outcomes of 324 patients with stage II or III rectal adenocarcinoma treated with induction chemotherapy followed by chemoradiotherapy (INCT-CRT) or chemoradiotherapy followed by consolidation chemotherapy (CRT-CNCT) and either total mesorectal excision (TME) or watch-and-wait on the basis of tumor response. Patients in both groups received 4 months of infusional fluorouracil-leucovorin-oxaliplatin or capecitabine-oxaliplatin and 5,000 to 5,600 cGy of radiation combined with either continuous infusion fluorouracil or capecitabine during radiotherapy. The trial was designed as two stand-alone studies with disease-free survival (DFS) as the primary end point for both groups, with a comparison to a null hypothesis on the basis of historical data. The secondary end point was TME-free survival.

RESULTS

Median follow-up was 3 years. Three-year DFS was 76% (95% CI, 69 to 84) for the INCT-CRT group and 76% (95% CI, 69 to 83) for the CRT-CNCT group, in line with the 3-year DFS rate (75%) observed historically. Three-year TME-free survival was 41% (95% CI, 33 to 50) in the INCT-CRT group and 53% (95% CI, 45 to 62) in the CRT-CNCT group. No differences were found between groups in local recurrence-free survival, distant metastasis-free survival, or overall survival. Patients who underwent TME after restaging and patients who underwent TME after regrowth had similar DFS rates.

CONCLUSION

Organ preservation is achievable in half of the patients with rectal cancer treated with total neoadjuvant therapy, without an apparent detriment in survival, compared with historical controls treated with chemoradiotherapy, TME, and postoperative chemotherapy.

Organ Preservation in Patients With Rectal Adenocarcinoma Treated With Total Neoadjuvant Therapy

PURPOSE

Prospective data on the efficacy of a watch-and-wait strategy to achieve organ preservation in patients with locally advanced rectal cancer treated with total neoadjuvant therapy are limited.

METHODS

In this prospective, randomized phase II trial, we assessed the outcomes of 324 patients with stage II or III rectal adenocarcinoma treated with induction chemotherapy followed by chemoradiotherapy (INCT-CRT) or chemoradiotherapy followed by consolidation chemotherapy (CRT-CNCT) and either total mesorectal excision (TME) or watch-and-wait on the basis of tumor response. Patients in both groups received 4 months of infusional fluorouracil-leucovorin-oxaliplatin or capecitabine-oxaliplatin and 5,000 to 5,600 cGy of radiation combined with either continuous infusion fluorouracil or capecitabine during radiotherapy. The trial was designed as two stand-alone studies with disease-free survival (DFS) as the primary end point for both groups, with a comparison to a null hypothesis on the basis of historical data. The secondary end point was TME-free survival.

RESULTS

Median follow-up was 3 years. Three-year DFS was 76% (95% CI, 69 to 84) for the INCT-CRT group and 76% (95% CI, 69 to 83) for the CRT-CNCT group, in line with the 3-year DFS rate (75%) observed historically. Three-year TME-free survival was 41% (95% CI, 33 to 50) in the INCT-CRT group and 53% (95% CI, 45 to 62) in the CRT-CNCT group. No differences were found between groups in local recurrence-free survival, distant metastasis-free survival, or overall survival. Patients who underwent TME after restaging and patients who underwent TME after regrowth had similar DFS rates.

CONCLUSION

Organ preservation is achievable in half of the patients with rectal cancer treated with total neoadjuvant therapy, without an apparent detriment in survival, compared with historical controls treated with chemoradiotherapy, TME, and postoperative chemotherapy.

Survival After Induction Chemotherapy and Chemoradiation Versus Chemoradiation and Adjuvant Chemotherapy for Locally Advanced Rectal Cancer

BACKGROUND

Total neoadjuvant therapy (TNT) improves tumor response in locally advanced rectal cancer (LARC) patients compared to neoadjuvant chemoradiotherapy alone. The effect of TNT on patient survival has not been fully investigated.

MATERIALS AND METHODS

This was a retrospective case series of patients with LARC at a comprehensive cancer center. Three hundred and eleven patients received chemoradiotherapy (chemoRT) as the sole neoadjuvant treatment and planned adjuvant chemotherapy, and 313 received TNT (induction fluorouracil and oxaliplatin-based chemotherapy followed by chemoradiotherapy in the neoadjuvant setting). These patients then underwent total mesorectal excision or were entered in a watch-and-wait protocol. The proportion of patients with complete response (CR) after neoadjuvant therapy (defined as pathological CR or clinical CR sustained for 2 years) was compared by the χ2 test. Disease-free survival (DFS), local recurrence-free survival, distant metastasis-free survival, and overall survival were assessed by Kaplan-Meier analysis and log-rank test. Cox regression models were used to further evaluate DFS.

RESULTS

The rate of CR was 20% for chemoRT and 27% for TNT (P=.05). DFS, local recurrence-free survival, metastasis-free survival, and overall survival were no different. Disease-free survival was not associated with the type of neoadjuvant treatment (hazard ratio [HR] 1.3; 95% confidence interval [CI] 0.93-1.80; P = .12).

CONCLUSIONS

Although TNT does not prolong survival than neoadjuvant chemoradiotherapy plus intended postoperative chemotherapy, the higher response rate associated with TNT may create opportunities to preserve the rectum in more patients with LARC.

MRI at Restaging After Neoadjuvant Therapy for Rectal Cancer Overestimates Circumferential Resection Margin Proximity as Determined by Comparison With Whole-Mount Pathology

BACKGROUND

Current guidelines recommend restaging with MRI after neoadjuvant therapy for rectal cancer, but the accuracy of restaging MRI in estimating circumferential margin involvement requires additional clarification.

OBJECTIVE

The objective of this study was to measure the accuracy of circumferential resection margin assessment by MRI after neoadjuvant therapy and identify characteristics associated with accuracy.

DESIGN

MRI data were retrospectively analyzed for concordance with the findings of whole-mount pathology analysis of the corresponding surgical specimens. Univariate and multivariate logistic regression analyses were performed to identify characteristics associated with accuracy.

SETTING

This study was conducted at a comprehensive cancer center.

PATIENTS

Included in the study were consecutive patients who underwent total mesorectal excision for rectal cancer between January 2018 and March 2020 after receiving neoadjuvant therapy and undergoing restaging with MRI.

MAIN OUTCOME MEASURES

The primary outcome of this study included accuracy, sensitivity, specificity, and positive and negative predictive values for categorizing the circumferential resection margin as threatened; mean and paired mean differences were in proximity of the margin.

RESULTS

Of the 94 patients included in the analysis, 39 (41%) had a threatened circumferential resection margin according to MRI at restaging, but only 17 (18%) had a threatened margin based on pathology. The accuracy of MRI in identifying a threatened margin was 63.8%, with margin proximity overestimated by 0.4 cm on average. In multivariate logistic regression, anterior location of the margin and tumor proximity to the anal verge were independently associated with reduced MRI accuracy.

LIMITATIONS

A limitation was the retrospective design at a single institution.

CONCLUSIONS

The knowledge that MRI-based restaging after neoadjuvant therapy overestimates circumferential margin proximity may render some surgical radicality unnecessary and thereby help avoid the associated morbidity. With the recognition that MRI-based assessment of margin proximity may not be reliable for anterior margin and for distal tumors, radiologists may want to use greater caution in interpreting images of tumors with these characteristics and to acknowledge the uncertainty in their reports. See Video Abstract at http://links.lww.com/DCR/B814.

LA IRM EN LA REESTADIFICACIN LUEGO DE TERAPIA NEOADYUVANTE EN EL CNCER DE RECTO SOBRESTIMA LA PROXIMIDAD DEL MARGEN DE RESECCIN CIRCUNFERENCIAL SEGN LO DETERMINADO COMPARATIVAMENTE CON LA PIEZA DE ANATOMOPATOLOGA

ANTECEDENTES:Las pautas actuales recomiendan la re-estadificación por medio de la resonancia magnética luego de terapia neoadyuvante en los casos de cáncer de recto, pero la precisión de la reevaluación con la IRM para estimar el grado de implicación del margen circunferencial requiere aclaraciones adicionales.OBJETIVO:Medir el grado de exactitud en la evaluación del margen de resección circunferencial mediante resonancia magnética después de la terapia neoadyuvante e identificar las características asociadas con la precisión.DISEÑO:Se analizaron retrospectivamente los datos de resonancia magnética para determinar la concordancia entre los hallazgos del análisis de la pieza de anatamopatología y las muestras quirúrgicas correspondientes. Se realizó el análisis de regresión logística univariada y multivariada para identificar las características asociadas con la exactitud.AJUSTE:Centro oncológico integral.PACIENTES:Todos aquellos que se sometieron consecutivamente a una excisión total del mesorrecto por cáncer rectal entre Enero 2018 y Febrero 2020 luego de recibir terapia neoadyuvante y someterse a una re-estadificación por imágenes de resonancia magnética (IRM).PRINCIPALES MEDIDAS DE RESULTADO:La exactitud, la sensibilidad y especificidad; los valores predictivos positivos y negativos para categorizar el margen de resección circunferencial como amenazado; la diferencia media y las medias pareadas de proximidad a los margenes.RESULTADOS:De los 94 pacientes incluidos en el análisis, 39 (41%) tenían un margen de resección circunferencial amenazado según la resonancia magnética en la re-estadificación, pero solo 17 (18%) tenían un margen amenazado basado en la patología. La precisión de la resonancia magnética para identificar un margen amenazado fue del 63,8%, con la proximidad del margen sobreestimada en 0,4 cm en promedio. En la regresión logística multivariada, la ubicación anterior de los bordes de resección y la proximidad del tumor al margen anal se asociaron de forma independiente con la reducción en la precisión de la resonancia magnética.LIMITACIONES:Diseño retrospectivo en una institución única.CONCLUSIONES:El saber que la re-estadificación basada en la IRM, luego de terapia neoadyuvante sobreestima la proximidad de la lesión a los márgenes circunferenciales, hace innecesaria cierta radicalidad quirúrgica complementaria, lo que ayuda a evitar morbilidad asociada. Reconociendo que la evaluación de proximidad de los márgenes de resección basada en la resonancia magnética, no puede ser confiable en casos de márgenes anteriores y en casos de tumores distales. Los radiólogos recomiendan tener más precaución en la interpretación de imágenes de tumores con estas características y reconocen cierto desasosiego en sus informes. Consulte Video Resumen en http://links.lww.com/DCR/B814.

Molecular Characterization of Peritoneal Mesotheliomas

INTRODUCTION

Malignant peritoneal mesothelioma (MPeM) is clinically distinct and less studied than malignant pleural mesothelioma. We report the genomic and immunophenotypic features of a prospectively collected MPeM cohort.

METHODS

Next-generation sequencing (NGS) was performed on MPeM tumors. Genomic near-haploidization (GNH) was assessed. WT1, BAP1, mesothelin, VISTA, and programmed death-ligand 1 were evaluated by immunohistochemistry (IHC) when tissue was available. Overall survival was stratified by selected genomic and IHC features.

RESULTS

A total of 50 consented patients with MPeM (45 epithelioid, 5 nonepithelioid) were studied exhibiting common alterations in BAP1 (60%; 30 of 50), NF2 (24%; 12 of 50) SETD2 (22%; 11 of 50), and TP53 (16%; 8 of 50). A total of 76% (38 of 50) of specimens were assessable for allele-specific copy number analysis; 8% (3 of 38) had GNH. IHC positivity rates were 93% (37 of 40) for mesothelin, 96% (46 of 48) for WT1, 50% (19 of 38) for programmed death-ligand 1, and 89% (34 of 38) for VISTA. BAP1 loss by IHC was observed in 76% (29 of 38), including five wild-type on NGS. Combining NGS and IHC for BAP1, overall survival was worse with alteration or loss compared with wild-type or retained in all patients (n = 37 versus 13, 43.8 versus 117.3 mo, p = 0.04) Three of 30 patients had a pathogenic germline variant: POT1 I78T, MUTYH R109Y, and BAP1 E402∗.

CONCLUSIONS

MPeM has distinct biology and genomic composition. CDKN2A/B alterations were rare in MPeM, whereas BAP1, NF2, TP53, SETD2, and LATS2 were common. BAP1 alteration/loss was associated with shorter survival when all patients were included. A notable minority of specimens had GNH associated with NF2, TP53, and SETDB1 mutations. Pathogenic germline mutations were found in 3 of 30 patients.

Adoption of Organ Preservation and Surgeon Variability for Patients with Rectal Cancer Does Not Correlate with Worse Survival

BACKGROUND AND OBJECTIVES

Watch-and-wait is variably adopted by surgeons and the impact of this on outcomes is unknown. We compared the disease-free survival and organ preservation rates of locally advanced rectal cancer patients treated by expert colorectal surgeons at a comprehensive cancer center.

METHODS

This study included retrospective data on patients diagnosed with stage II/III rectal adenocarcinoma from January 2013 to June 2017 who initiated neoadjuvant therapy (either with chemoradiation, chemotherapy, or a combination of both) and were treated by an expert colorectal surgeon.

RESULTS

Overall, 444 locally advanced rectal cancer patients managed by five surgeons were included. Tumor distance from the anal verge, type of neoadjuvant therapy, and organ preservation rates varied by treating surgeon. There was no difference in disease-free survival after stratifying by the treating surgeon (p = 0.2). On multivariable analysis, neither the type of neoadjuvant therapy nor the treating surgeon was associated with disease-free survival.

CONCLUSIONS

While neoadjuvant therapy type and organ preservation rates varied among surgeons, there were no meaningful differences in disease-free survival. These data suggest that among expert colorectal surgeons, differing thresholds for selecting patients for watch-and-wait do not affect survival.

Treatment of Platinum Nonresponsive Metastatic Malignant Peritoneal Mesothelioma With Combination Chemoimmunotherapy

Malignant peritoneal mesothelioma is a rare cancer associated with minimal durable disease control with chemotherapy and poor overall survival. The efficacy of combined cytotoxic chemotherapy and immune checkpoint inhibitors (ICIs) in malignant peritoneal mesothelioma has not previously been studied. We describe the clinical course of 2 patients with metastatic peritoneal mesothelioma who both relapsed with platinum nonresponsive disease after initial cytoreductive surgery and chemotherapy. In both cases, addition of pembrolizumab to platinum and pemetrexed treatment resulted in a substantial partial and a near complete disease response. Notably, both patients possessed tumors without validated biomarkers of ICI response, including low tumor mutational burden and negative programmed death ligand-1. The unique genomic landscape of each patient may have enabled increased tumor immunorecognition and ICI efficacy. In addition, chemotherapy priming of the tumor microenvironment may have improved ICI response. This report supports future research to characterize the benefit of combination chemotherapy and ICI in peritoneal mesothelioma.

Intraperitoneal Pretargeted Radioimmunotherapy for Colorectal Peritoneal Carcinomatosis

Peritoneal carcinomatosis (PC) is considered incurable, and more effective therapies are needed. Herein we test the hypothesis that GPA33-directed intracompartmental pretargeted radioimmunotherapy (PRIT) can cure colorectal peritoneal carcinomatosis. Nude mice were implanted intraperitoneally with luciferase-transduced GPA33-expressing SW1222 cells for aggressive peritoneal carcinomatosis (e.g., resected tumor mass 0.369 ± 0.246 g; n = 17 on day 29). For GPA33-PRIT, we administered intraperitoneally a high-affinity anti-GPA33/anti-DOTA bispecific antibody (BsAb), followed by clearing agent (intravenous), and lutetium-177 (Lu-177) or yttrium-86 (Y-86) radiolabeled DOTA-radiohapten (intraperitoneal) for beta/gamma-emitter therapy and PET imaging, respectively. The DOTA-radiohaptens were prepared from S-2-(4-aminobenzyl)-1,4,7, 10-tetraazacyclododecane tetraacetic acid chelate (DOTA-Bn). Efficacy and toxicity of single- versus three-cycle therapy were evaluated in mice 26-27 days post-tumor implantation. Single-cycle treatment ([177Lu]LuDOTA-Bn 111 MBq; tumor dose: 4,992 cGy) significantly prolonged median survival (MS) approximately 2-fold to 84.5 days in comparison with controls (P = 0.007). With three-cycle therapy (once weekly, total 333 MBq; tumor dose: 14,975 cGy), 6/8 (75%) survived long-term (MS > 183 days). Furthermore, for these treated long-term survivors, 1 mouse was completely disease free (microscopic "cure") at necropsy; the others showed stabilized disease, which was detectable during PET-CT using [86Y]DOTA-Bn. Treatment controls had MS ranging from 42-52.5 days (P < 0.001) and 19/20 mice succumbed to progressive intraperitoneal disease by 69 days. Multi-cycle GPA33 DOTA-PRIT significantly prolongs survival with reversible myelosuppression and no chronic marrow (929 cGy to blood) or kidney (982 cGy) radiotoxicity, with therapeutic indices of 12 for blood and 12 for kidneys. MTD was not reached.

Abstract P168: Pretargeted radioimmunotherapy using 225Ac for intraperitoneal Her2-expressing epithelial ovarian carcinoma xenografts

Objectives Epithelial ovarian carcinoma (EOC) is a common and lethal gynecologic malignancy that frequently presents as advanced staged disease, such as peritoneal carcinomatosis (PC). We previously reported cures in BT-474 murine xenografts with Pretargeted Radioimmunotherapy (PRIT) using 177Lu radiohaptens targeting Her2 via a bispecific antibody (BsAb). Here-in we report the use of PRIT with alpha emitter 225Ac labelled PrDOTA to treat a PC model of SKOV3, a Her2+ cell line of EOC. Methods 6 wk old female athymic nude mice inoculated IP with 1E5 luciferase/GFP-transfected SKOV3 cells were separated into 5 groups (n=10). Treatment mice received 1 or 2 cycles of Anti-Her2-C825 BsAb + [225Ac]PrDOTA (Her2-Targeted), at 14 and 21 days after inoculation, respectively. Control groups received Anti-Her2 BsAb only, Anti-GPA33 BsAb + [225Ac]PrDOTA (Off-Targeted) or no treatment. On cycle day 1, the mice were injected IP with 0.25mg (1.19nmol) BsAb. On cycle day 2, 25µg (2.76nmol) CCA16-DOTAY clearing agent (CA) was given IV 22h from BsAb. Mice in therapy groups were injected IP with 1µCi (0.74-0.79nmol) [225Ac]PrDOTA-Bn 4h after CA. Weekly weights and BLIs with IP cavity ROIs were obtained and normalized to the respective values for each mouse at week 0 pre-treatment. End points: weight loss &gt;20% baseline, moribund, or severe abdominal distension. At 154 days, 15 surviving treatment and 1 untreated control mice were submitted for hematology and histopathology. Results Histologic cures and prolonged survival were demonstrated in treatment mice (17/20 at 133 days) as compared to control mice (12/27 at 133 d, Logrank p&lt;0.04). 3 mice from control groups were excluded due to BLI values &lt;50% background in the first 3 weeks, suggesting no tumor burden. Tumors, as measured by normalized BLI values (nBLI), regressed in treatment mice when compared to control mice (2-way ANOVA p&lt;0.01). nBLI values between treatment mice (1 and 2 cycles) and control mice (BsAb only, Off-target, no treatment) diverged at week 10 (Tukey’s test p&lt;0.01). There was no difference in nBLI values between mice treated with 1 or 2 cycles of targeted PRIT (Tukey’s test p&gt;0.05; all weeks). BLI of mice treated with 1 and 2 cycle of Her2 PRIT decreased 47% when compared to baseline within 1 week (T test p=0.04), suggesting treatment effects as early as 1 week. There were no differences in weights when compared to baseline (2-way ANOVA p&gt;0.05). While the untreated mouse had high peritoneal adenocarcinoma tumor burden, there was no histologic evidence of viable neoplasia in 15/15 submitted treatment mice. Treatment mice had moderate renal tubular degenerative lesions on histology, but this did not affect renal function based on serum BUN or Cr. All hematologic parameters were within normal limits for treated mice. Conclusions 1 and 2 cycles of [225Ac]PrDOTA-PRIT against Her2 resulted in histologic cures and prolonged survival in IP SKOV3 xenografts with minimal toxicity. The anti-Her2 PrDOTA-PRIT system is a promising theranostic approach for otherwise incurable PC.

Citation Format: Sebastian K. Chung, Christopher S. Chandler, Daniela Burnes Vargas, Shin H. Seo, Michael R. McDevitt, Darren Veach, Blesida Punzalan, Xu Hong, Hong-fen Guo, Garrett M. Nash, Andrea Cercek, Nai-Kong V. Cheung, Steven M. Larson, Sarah M. Cheal. Pretargeted radioimmunotherapy using 225Ac for intraperitoneal Her2-expressing epithelial ovarian carcinoma xenografts [abstract]. In: Proceedings of the AACR-NCI-EORTC Virtual International Conference on Molecular Targets and Cancer Therapeutics; 2021 Oct 7-10. Philadelphia (PA): AACR; Mol Cancer Ther 2021;20(12 Suppl):Abstract nr P168.

Comparing outcomes of robotic versus open mesorectal excision for rectal cancer

Background

The outcomes of robot-assisted mesorectal excision for rectal cancer, compared with open resection, have not been fully characterized.

Methods

A retrospective analysis of pathologic, short-term, and long-term outcomes in patients with rectal adenocarcinoma who underwent total or tumour-specific mesorectal excision at a high-volume cancer centre between 2008 and 2017 was conducted. Outcomes after robotic and open surgery were compared on an intention-to-treat basis.

Results

Out of 1048 resections performed, 1018 patients were reviewed, with 638 who underwent robotic surgery and 380 open surgery. Robotic surgery was converted to the open approach in 17 (2.7 per cent) patients. Patients who underwent robotic surgery were younger (median 54 (range 22–91) years versus median 58 (range 18–97) years; P < 0.001), had higher tumours (median 80 (range 0–150) mm from the anal verge versus median 70 (0–150) mm; P = 0.001), and were less likely to have received neoadjuvant therapy (64 per cent versus 73 per cent; P = 0.003). For patients who underwent a robotic total mesorectal excision, the operating time was longer (median 283.5 (range 117–712) min versus median 249 (range 70–661) min; P < 0.001). However, the rate of complications was lower (29 per cent versus 45 per cent; P < 0.001) and length of hospital stay was shorter (median 5 (range 1–32) days versus median 7 (range 0–137) days; P < 0.001). Median follow-up of survivors was 2.9 years. The proportion of patients with a positive circumferential resection margin did not differ between the groups, nor did the rate of local recurrence (robotic versus open: 3.7 per cent, 95 per cent c.i. 1.9 to 5.6 versus 2.8 per cent, 95 per cent c.i. 1.0 to 4.6; P = 0.400), systemic recurrence (robotic versus open: 11.7 per cent, 95 per cent c.i. 8.5 to 14.8 versus 13.0 per cent, 95 per cent c.i. 9.2 to 16.5; P = 0.300), or overall survival (robotic versus open: 97.8 per cent, 95 per cent c.i. 96.3 to 99.3 versus 93.5 per cent, 95 per cent c.i. 90.8 to 96.2; P = 0.050). The same results were documented in a subanalysis of 370 matched patients, including 185 who underwent robotic surgery and 185 open surgery, for the overall incidence of any postoperative complications, overall survival, disease-free survival, local recurrence, and systemic recurrence.

Conclusion

In patients with rectal cancer who are candidates for curative resection, robotic mesorectal excision is associated with lower complication rates, shorter length of stay, and equivalent oncologic outcomes, compared with open mesorectal excision.

Meaningful words in rectal MRI synoptic reports: How "polypoid" may be prognostic

PURPOSE

This study explored the clinicopathologic outcomes of rectal tumor morphological descriptors used in a synoptic rectal MRI reporting template and determined that prognostic differences were observed.

METHODS

This retrospective study was conducted at a comprehensive cancer center. Fifty patients with rectal tumors for whom the synoptic descriptor "polypoid" was chosen by three experienced radiologists were compared with ninety comparator patients with "partially circumferential" and "circumferential" rectal tumors. Two radiologists re-evaluated all cases. The outcome measures were agreement among two re-interpreting radiologists, clinical T staging with MRI (mrT) and descriptive nodal features, and degrees of wall attachment of tumors (on MRI) compared with pathological (p) T and N stage when available.

RESULTS

Re-evaluation by two radiologists showed moderate to excellent agreement in tumor morphology, presence of a pedicle, and degree of wall attachment (k = 0.41-0.76) and excellent agreement on lymph node presence and size (ICC = 0.83-0.91). Statistically significant lower mrT stage was noted for polypoid morphology, wherein 98% were mrT1/2, while only 7% and 2% of partially circumferential and circumferential tumors respectively were mrT1/2. Pathologic T and N stages among the three morphologies also differed significantly, with only 14% of polypoid cases higher than stage pT2 compared to 48% of partially circumferential cases and 60% of circumferential cases.

CONCLUSION

Using a "polypoid" morphology in rectal cancer MRI synoptic reports revealed a seemingly distinct phenotype with lower clinical and pathologic T and N stages when compared with alternative available descriptors.

PRECIS

"Polypoid" morphology in rectal cancer confers a lower clinical and pathologic T and N stage and may be useful in determining whether to proceed with surgery versus neoadjuvant treatment.

Primary Tumor-Related Complications and Salvage Outcomes in Patients with Metastatic Rectal Cancer and an Untreated Primary Tumor

BACKGROUND

For rectal cancer with unresectable metastases, current practice favors omitting interventions directed at the primary tumor in asymptomatic patients.

OBJECTIVE

This study aimed to determine the proportion of patients with primary tumor-related complications, characterize salvage outcomes, and measure survival in patients with metastatic rectal cancer who did not undergo upfront intervention for their primary tumor.

DESIGN

This is a retrospective analysis.

SETTING

This study was conducted at a comprehensive cancer center.

PATIENTS

Patients who presented between January 1, 2008, and December 31, 2015, with synchronous stage IV rectal cancer, an unresected primary tumor, and no prior primary tumor-directed intervention were selected.

MAIN OUTCOME MEASURES

The main outcome measured was the rate of primary tumor-related complications in the cohort that did not receive any primary tumor-directed intervention. The Kaplan-Meier method and Cox regression analysis were used to determine whether complications are associated with survival.

RESULTS

The cohort comprised 358 patients with a median age of 56 years (22-92). Median follow-up was 26 months (range, 1-93 months). Among the 168 patients (46.9%) who eventually underwent elective resection of the primary tumor, the surgery was performed with curative intent in 66 patients (18.4%) and preemptive intent in 102 patients (28.5%). Of the 190 patients who did not undergo an upfront or elective intervention for the primary tumor, 68 (35.8%) experienced complications. Nonsurgical intervention for complications was attempted in 34 patients with an overall success rate of 61.8% (21/34). Surgical intervention was performed in 47 patients (including 13 patients for whom nonsurgical intervention failed): diversion in 26 patients and resection in 21 patients. Of those 47 patients, 42 (89.4%) ended up with a colostomy or ileostomy.

LIMITATIONS

This study was conducted at a single center.

CONCLUSION

A significant proportion of patients with metastatic rectal cancer and untreated primary tumor experience primary tumor-related complications. These patients should be followed closely, and preemptive intervention (resection, diversion, or radiation) should be considered if the primary tumor progresses despite systemic therapy. See Video Abstract at http://links.lww.com/DCR/B400. COMPLICACIONES RELACIONADAS CON EL TUMOR PRIMARIO Y RESULTADOS DE RESCATE EN PACIENTES CON CÁNCER DE RECTO METASTÁSICO Y UN TUMOR PRIMARIO NO TRATADO: Para el cáncer de recto con metástasis no resecables, la práctica actual favorece la omisión de las intervenciones dirigidas al tumor primario en pacientes asintomáticos.Determinar la proporción de pacientes con complicaciones relacionadas con el tumor primario, caracterizar los resultados de rescate y medir la supervivencia en pacientes con cáncer rectal metastásico que no se sometieron a una intervención inicial para su tumor primario.Análisis retrospectivo.Centro oncológico integral.Pacientes que se presentaron entre el 1 de enero de 2008 y el 31 de diciembre de 2015 con cáncer de recto en estadio IV sincrónico, un tumor primario no resecado y sin intervención previa dirigida al tumor primario.Tasa de complicaciones relacionadas con el tumor primario en la cohorte que no recibió ninguna intervención dirigida al tumor primario. Se utilizó el método de Kaplan-Meier y el análisis de regresión de Cox para determinar si las complicaciones están asociadas con la supervivencia.La cohorte estuvo compuesta por 358 pacientes con una mediana de edad de 56 años (22-92). La mediana de seguimiento fue de 26 meses (rango, 1 a 93 meses). Entre los 168 pacientes (46,9%) que finalmente se sometieron a resección electiva del tumor primario, la cirugía se realizó con intención curativa en 66 pacientes (18,4%) y con intención preventiva en 102 pacientes (28,5%). De los 190 pacientes que no se sometieron a una intervención inicial o electiva para el tumor primario, 68 (35,8%) experimentaron complicaciones. Se intentó una intervención no quirúrgica para las complicaciones en 34 pacientes con una tasa de éxito global del 61,8% (21 de 34). La intervención quirúrgica se realizó en 47 pacientes (incluidos 13 pacientes en los que falló la intervención no quirúrgica): derivación en 26 pacientes y resección en 21 pacientes. De esos 47 pacientes, 42 (89,4%) terminaron con una colostomía o ileostomía.Único centro.Una proporción significativa de pacientes con cáncer de recto metastásico y primario no tratado experimentan complicaciones relacionadas con el tumor primario. Se debe hacer un seguimiento estrecho de estos pacientes y considerar la posibilidad de una intervención preventiva (resección, derivación o radiación) si el tumor primario progresa a pesar de la terapia sistémica. Consulte Video Resumen en http://links.lww.com/DCR/B400.

Characterization and Clinical Outcomes of DNA Mismatch Repair-deficient Small Bowel Adenocarcinoma

PURPOSE

The prevalence and clinical characteristics of small bowel adenocarcinomas (SBA) in the setting of Lynch syndrome have not been well studied. We characterized SBA according to DNA mismatch repair and/or microsatellite instability (MMR/MSI) and germline mutation status and compared clinical outcomes.

EXPERIMENTAL DESIGN

A single-institution review identified 100 SBAs. Tumors were evaluated for MSI via MSIsensor and/or corresponding MMR protein expression via IHC staining. Germline DNA was analyzed for mutations in known cancer predisposition genes, including MMR (MLH1, MSH2, MSH6, PMS2, and EPCAM). Clinical variables were correlated with MMR/MSI status.

RESULTS

Twenty-six percent (26/100; 95% confidence interval, 18.4-35.4) of SBAs exhibited MMR deficiency (MMR-D). Lynch syndrome prevalence was 10% overall and 38.5% among MMR-D SBAs. Median age at SBA diagnosis was similar in non-Lynch syndrome MMR-D versus MMR-proficient (MMR-P) SBAs (65 vs. 61; P = 0.75), but significantly younger in Lynch syndrome (47.5 vs. 61; P = 0.03). The prevalence of synchronous/metachronous cancers was 9% (6/67) in MMR-P versus 34.6% (9/26) in MMR-D SBA, with 66.7% (6/9) of these in Lynch syndrome (P = 0.0002). In the MMR-P group, 52.2% (35/67) of patients presented with metastatic disease, compared with 23.1% (6/26) in the MMR-D group (P = 0.008). In MMR-P stage I/II patients, 88.2% (15/17) recurred, compared with 18.2% (2/11) in the MMR-D group (P = 0.0002).

CONCLUSIONS

When compared with MMR-P SBA, MMR-D SBA was associated with earlier stage disease and lower recurrence rates, similar to observations in colorectal cancer. With a 38.5% prevalence in MMR-D SBA, germline Lynch syndrome testing in MMR-D SBA is warranted.

Correction to: Primary Tumor Location and Outcomes After Cytoreductive Surgery and Intraperitoneal Chemotherapy for Peritoneal Metastases of Colorectal Origin

In the original article there is a reference missing, in addition to its citations in the text. The reference is as follows.

Primary Tumor Location and Outcomes After Cytoreductive Surgery and Intraperitoneal Chemotherapy for Peritoneal Metastases of Colorectal Origin

BACKGROUND

The aim of this study is to evaluate outcomes in patients with peritoneal metastasis of colorectal cancer (pmCRC) who underwent cytoreductive surgery and intraperitoneal chemotherapy (CRS/IPC) in relation to the location of the primary tumor. Regional therapy, including cytoreductive surgery and intraperitoneal chemotherapy, has been associated with improved survival in patients with pmCRC. Location of the primary tumor has been shown to be prognostic in patients with metastasis.

PATIENTS AND METHODS

A retrospective review was performed for all patients who underwent complete cytoreduction and intraperitoneal chemotherapy from 2010 to 2017, examining patient and tumor characteristics, overall and recurrence-free survival, recurrence patterns, and tumor mutational profiles.

RESULTS

Ninety-three patients were included in the study: 49 (53%) with a right-sided and 44 (47%) with a left-sided primary tumor. Patients with a right-sided tumor had significantly shorter recurrence-free survival (median, 6.3 months; 95% CI, 4.7-8.1 months vs 12.3 months; 95% CI, 3.6-21.7 months; P = 0.02) and overall survival (median, 36.6 months; 95% CI, 26.4-46.9 months vs 83.3 months; 95% CI 44.2-122.4 months; P = 0.03). BRAF and KRAS mutations were more frequent in right-sided tumors, and APC and TP53 mutations were more frequent in left-sided tumors, which were more chromosomally instable. BRAF mutations were associated with early recurrence.

CONCLUSIONS

Tumor sidedness is a predictor of oncological outcomes after CRS/IPC. Tumor sidedness and molecular characteristics should be considered when counseling patients regarding expected outcomes and when selecting or stratifying pmCRC patients for clinical trials of regional therapy.

Monitoring an Ongoing Enhanced Recovery After Surgery (ERAS) Program: Adherence Improves Clinical Outcomes in a Comparison of Three Thousand Colorectal Cases

AIM

In 2014, Memorial Sloan Kettering Cancer Center was identified as an outlier for increased length of stay (LOS) after colorectal surgery. We subsequently implemented a comprehensive Enhanced Recovery After Surgery (ERAS) program in January 2016, which is continually monitored to target areas for improvement. The primary aim of this study was to evaluate the impact of a newly established ERAS program in a high-volume colorectal center over time.

METHOD

This was a retrospective cohort study, comparing 3000 sequential cancer patients who underwent elective colorectal surgery before and after ERAS implementation. Patients were divided into three groups (Pre-, Early, and Late ERAS). Adherence to ERAS process measures and outcomes (LOS, complications, and 30-day readmission) were compared among the three time periods.

RESULTS

Adherence to ERAS metrics significantly increased over time, from a median of 25% Pre-ERAS to 67% Early and 75% Late ERAS (p < 0.0001). Mean LOS decreased from 5.2 days Pre-ERAS to 4.5 Early and 4.0 Late ERAS (p < 0.0001). There were no differences in rates of complications or readmissions, and patients with shorter LOS had lower readmission rates. With ERAS, the readmission rate was 4.4% for patients discharged within 3 days, versus >10% for LOS ≥5 days (p < 0.0001).

CONCLUSION

Initiation of an ERAS program at a high-volume colorectal center was associated with decreased LOS, without increasing morbidity. Increased ERAS adherence was associated with a further decrease in LOS. Multidisciplinary monitoring to promote protocol adherence is necessary for maintaining a safe and effective ERAS program.

Mismatch Repair-Deficient Rectal Cancer and Resistance to Neoadjuvant Chemotherapy

PURPOSE

Evaluate response of mismatch repair-deficient (dMMR) rectal cancer to neoadjuvant chemotherapy.

EXPERIMENTAL DESIGN

dMMR rectal tumors at Memorial Sloan Kettering Cancer Center (New York, NY) were retrospectively reviewed for characteristics, treatment, and outcomes. Fifty patients with dMMR rectal cancer were identified by IHC and/or microsatellite instability analysis, with initial treatment response compared with a matched MMR-proficient (pMMR) rectal cancer cohort. Germline and somatic mutation analyses were evaluated. Patient-derived dMMR rectal tumoroids were assessed for chemotherapy sensitivity.

RESULTS

Of 21 patients receiving neoadjuvant chemotherapy (fluorouracil/oxaliplatin), six (29%) had progression of disease. In comparison, no progression was noted in 63 pMMR rectal tumors (P = 0.0001). Rectal cancer dMMR tumoroids reflected this resistance to chemotherapy. No genomic predictors of chemotherapy response were identified. Of 16 patients receiving chemoradiation, 13 (93%) experienced tumor downstaging; one patient had stable disease, comparable with 48 pMMR rectal cancers. Of 13 patients undergoing surgery, 12 (92%) had early-stage disease. Forty-two (84%) of the 50 patients tested positive for Lynch syndrome with enrichment of germline MSH2 and MSH6 mutations when compared with 193 patients with Lynch syndrome-associated colon cancer (MSH2, 57% vs 36%; MSH6, 17% vs 9%; P < 0.003).

CONCLUSIONS

Over one-fourth of dMMR rectal tumors treated with neoadjuvant chemotherapy exhibited disease progression. Conversely, dMMR rectal tumors were sensitive to chemoradiation. MMR status should be performed upfront in all locally advanced rectal tumors with careful monitoring for response on neoadjuvant chemotherapy and genetic testing for Lynch syndrome in patients with dMMR rectal cancer.

Coaltered Ras/B-raf and TP53 Is Associated with Extremes of Survivorship and Distinct Patterns of Metastasis in Patients with Metastatic Colorectal Cancer

PURPOSE

We aimed to investigate genomic correlates underlying extremes of survivorship in metastatic colorectal cancer and their applicability in informing survival in distinct subsets of patients with metastatic colorectal cancer.

EXPERIMENTAL DESIGN

We examined differences in oncogenic somatic alterations between metastatic colorectal cancer cohorts demonstrating extremes of survivorship following complete metastasectomy: ≤2-year (n = 17) and ≥10-year (n = 18) survivors. Relevant genomic findings, and their association with overall survival (OS), were validated in two independent datasets of 935 stage IV and 443 resected stage I-IV patients.

RESULTS

In the extremes-of-survivorship cohort, significant co-occurrence of KRAS hotspot mutations and TP53 alterations was observed in ≤2-year survivors (P < 0.001). When validating these findings in the independent cohort of 935 stage IV patients, incorporation of the cumulative effect of any oncogenic Ras/B-raf (i.e., either KRAS, NRAS, or BRAF) and TP53 alteration generated three prognostic clusters: (i) TP53-altered alone (median OS, 132 months); (ii) Ras/B-raf-altered alone (65 months) or Ras/B-raf- and TP53 pan-wild-type (60 months); and (iii) coaltered Ras/B-raf-TP53 (40 months; P < 0.0001). Coaltered Ras/B-raf-TP53 was independently associated with mortality (HR, 2.47; 95% confidence interval, 1.91-3.21; P < 0.001). This molecular profile predicted survival in the second independent cohort of 443 resected stage I-IV patients. Coaltered Ras/B-raf-TP53 was associated with worse OS in patients with liver (n = 490) and lung (n = 172) but not peritoneal surface (n = 149) metastases. Moreover, coaltered Ras/B-raf-TP53 tumors were significantly more likely to involve extrahepatic metastatic sites with limited salvage options.

CONCLUSIONS

Genomic analysis of extremes of survivorship following colorectal cancer metastasectomy identifies a prognostic role for coaltered Ras/B-raf-TP53 and its association with distinct patterns of colorectal cancer metastasis.

A rectal cancer organoid platform to study individual responses to chemoradiation

Rectal cancer (RC) is a challenging disease to treat that requires chemotherapy, radiation and surgery to optimize outcomes for individual patients. No accurate model of RC exists to answer fundamental research questions relevant to patients. We established a biorepository of 65 patient-derived RC organoid cultures (tumoroids) from patients with primary, metastatic or recurrent disease. RC tumoroids retained molecular features of the tumors from which they were derived, and their ex vivo responses to clinically relevant chemotherapy and radiation treatment correlated with the clinical responses noted in individual patients' tumors. Upon engraftment into murine rectal mucosa, human RC tumoroids gave rise to invasive RC followed by metastasis to lung and liver. Importantly, engrafted tumors displayed the heterogenous sensitivity to chemotherapy observed clinically. Thus, the biology and drug sensitivity of RC clinical isolates can be efficiently interrogated using an organoid-based, ex vivo platform coupled with in vivo endoluminal propagation in animals.

Changes in the multidisciplinary management of rectal cancer from 2009 to 2015 and associated improvements in short-term outcomes

AIM

Significant recent changes in management of locally advanced rectal cancer (LARC) include preoperative staging, use of extended neoadjuvant therapies and minimally invasive surgery (MIS). This study was aimed at characterizing these changes and associated short-term outcomes.

METHOD

We retrospectively analysed treatment and outcome data from patients with T3/4 or N+ LARC ≤ 15 cm from the anal verge who were evaluated at a comprehensive cancer centre in 2009-2015.

RESULTS

In total, 798 patients were identified and grouped into five cohorts based on treatment year: 2009-2010, 2011, 2012, 2013 and 2014-2015. Temporal changes included increased reliance on MRI staging, from 57% in 2009-2010 to 98% in 2014-2015 (P < 0.001); increased use of total neoadjuvant therapy, from 17% to 76% (P < 0.001); and increased use of MIS, from 33% to 70% (P < 0.001). Concurrently, median hospital stay decreased (from 7 to 5 days; P < 0.001), as did the rates of Grade III-V complications (from 13% to 7%; P < 0.05), surgical site infections (from 24% to 8%; P < 0.001), anastomotic leak (from 11% to 3%; P < 0.05) and positive circumferential resection margin (from 9% to 4%; P < 0.05). TNM downstaging increased from 62% to 74% (P = 0.002).

CONCLUSION

Shifts toward MRI-based staging, total neoadjuvant therapy and MIS occurred between 2009 and 2015. Over the same period, treatment responses improved, and lengths of stay and the incidence of complications decreased.