ABSTRACT
Background: Recent data have demonstrated that in locally advanced rectal cancer (LARC), a total neoadjuvant therapy (TNT) approach improves compliance with chemotherapy and increases rates of tumor response compared to neoadjuvant chemoradiation (CRT) alone. They further indicate that the optimal sequencing of TNT involves consolidation (rather than induction) chemotherapy to optimize complete response rates. Data, largely from retrospective studies, have also shown that patients with clinical complete response (cCR) after neoadjuvant therapy may be managed safely with the watch and wait approach (WW) instead of preemptive total mesorectal resection (TME). However, the optimal consolidation chemotherapy regimen to achieve cCR has not been established, and a randomized clinical trial has not robustly evaluated cCR as a primary endpoint. Collaborating with a multidisciplinary oncology team and patient groups, we designed this NCI-sponsored study of chemotherapy intensification to address these issues and to drive up cCR rates, to provide opportunity for organ preservation, improve quality of life for patients and improve survival outcomes. Methods: In this NCI-sponsored multi-group randomized, seamless phase II/III trial (1:1), up to 760 patients with LARC, T4N0, any T with node positive disease (any T, N+) or T3N0 requiring abdominoperineal resection or coloanal anastomosis and distal margin within 12 cm of anal verge will be enrolled. Stratification factors include tumor stage (T4 vs T1-3), nodal stage (N+ vs N0) and distance from anal verge (0-4; 4-8; 8-12 cm). Patients will be randomized to receive neoadjuvant long course chemoradiation (LCRT) followed by consolidation doublet (mFOLFOX6 or CAPOX) or triplet chemotherapy (mFOLFIRINOX) for 3-4 months. LCRT in both arms involves 4500 cGy in 25 fractions over 5 weeks + 900 cGy boost in 5 fractions with a fluoropyrimidine (capecitabine preferred). Patients will undergo assessment 8-12 (+/- 4) weeks post-TNT completion. The primary endpoint for the phase II portion will compare cCR between treatment arms. A total number of 296 evaluable patients (148 per arm) will provide statistical power of 90.5% to detect an 17% increase in cCR rate, at a one-sided alpha=0.048. The primary endpoint for the phase III portion will compare disease-free survival (DFS) between treatment arms. A total of 285 DFS events will provide 85% power to detect an effect size of hazard ratio 0.70 at a one-sided alpha of 0.025, requiring enrollment of 760 patients (380 per arm). Secondary objectives include time-to event outcomes (overall survival, organ preservation time and time to distant metastasis) and adverse effects. Biospecimens including archival tumor tissue, plasma and buffy coat in EDTA tubes, and serial rectal MRIs will be collected for exploratory correlative research. This study, activated in late 2022, is open across the NCTN and has a current accrual of 312. Support: U10CA180821, U10CA180882, U24 CA196171; https://acknowledgments.alliancefound.org . Discussion: Building off of data from modern day rectal cancer trials and patient input from national advocacy groups, we have designed the current trial studying chemotherapy intensification via a consolidation chemotherapy approach with the intent to enhance cCR and DFS rates, increase organ preservation rates, and improve quality of life for patients with rectal cancer. Trial Registration: Clinicaltrials.gov ID: NCT05610163 ; Support includes U10CA180868 (NRG) and U10CA180888 (SWOG).
ABSTRACT
BACKGROUND: Extent of peritoneal metastases (PM) is among the most powerful prognostic factors for survival after cytoreductive surgery (CRS). This study aimed to compare the Peritoneal Cancer Index (PCI) and the Dutch region count as tools for staging PM of colorectal cancer. The Dutch region count is a simpler classification that distinguishes seven rather than 13 abdominal regions. Presence or absence of PM is recorded. METHODS: This was a retrospective cohort study in two tertiary referral centres in the Netherlands. Consecutive patients with colorectal PM who were intentionally treated with CRS and subsequent hyperthermic intraperitoneal chemotherapy in 2016 and 2017 were included. The PCI and Dutch region count were both recorded during laparotomy. Correlation between scoring tools was calculated using Spearman's rank correlation coefficient. Diagnostic values were calculated for different cut-off values of the PCI, alongside the Dutch region count. The correlation of both scores was determined for the exploration and validation cohorts separately. RESULTS: In the exploration and validation cohorts, 73 and 85 patients respectively were included. Spearman's correlation coefficients of 0·897 and 0·961 were observed for continuous scores of the Dutch region count and PCI in the exploration and validation group respectively. A cut-off value of 20 for the PCI score and 5 for the Dutch region count showed 91·9 and 94·5 per cent sensitivity, and 81·8 and 91·7 per cent specificity, respectively. CONCLUSION: The Dutch region count correlated well with the PCI score, and may help to simplify reporting of the extent of peritoneal disease.
ANTECEDENTES: La extensión de las metástasis peritoneales (peritoneal metastases, PM) es uno de los factores pronósticos más importantes para la supervivencia después de la cirugía citorreductora (cytoreductive surgery, CRS). El objetivo de este estudio fue comparar el índice de carcinomatosis peritoneal (Peritoneal Cancer Index, PCI) y el recuento holandés por regiones como herramientas para la estadificación de las PM del cáncer colorrectal. El recuento holandés por regiones es una clasificación más simple que distingue 7 regiones abdominales en lugar de 13. En dichas regiones abdominales se registró la presencia o ausencia de PM. MÉTODOS: Se llevó a cabo un estudio de cohortes retrospectivo en dos centros de referencia terciarios en los Países Bajos. Se incluyeron pacientes consecutivos con PM de origen colorrectal que fueron tratados con CRS seguida de quimioterapia intraperitoneal hipertérmica (hyperthermic intraperitoneal chemotherapy, HIPEC) en 2016 y 2017. Durante la laparotomía se recogieron datos del índice PCI y de la clasificación de las regiones abdominales. Se utilizó el coeficiente de correlación de Spearman para analizar la correlación entre estas dos herramientas de puntuación. Se calculó la precisión diagnóstica en función de diferentes umbrales del índice PCI junto con los datos del recuento por regiones. Asimismo, se calcularon las correlaciones entre ambas puntuaciones en las cohortes de exploración y validación por separado. RESULTADOS: Se incluyeron 73 pacientes en la cohorte de exploración y 85 en la de validación. Los coeficientes de correlación de Spearman eran de 0,987 para puntuaciones continuas del recuento holandés por regiones abdominales y del PCI en la cohorte de exploración y de 0,961 en la cohorte de validación. Los umbrales de corte de 20 para el índice PCI y de 5 para el recuento por regiones demostraron sensibilidades de 91,9% y 94,5%, y especificidades de 81,8% y 91,7%, respectivamente. CONCLUSIÓN: El recuento holandés por regiones abdominales se correlacionó bien con el PCI y puede ser útil para simplificar la extensión de la enfermedad peritoneal.
