Cumulative Incidence, Risk Factors, and Overall Survival of Disease Recurrence after Curative Resection of Stage II-III Colorectal Cancer: A Population-based Study

Real-world data are necessitated to counsel patients about the risk for recurrent disease after curative treatment of colorectal cancer. This study provided a population-based overview of the epidemiology of recurrent disease in patients with surgically resected stage II/III colorectal cancer.Patients diagnosed with stage II/III primary colorectal cancer between July and December 2015 were selected from the Netherlands Cancer Registry (N = 3,762). Cumulative incidence of recurrent disease was estimated, and multivariable competing risk regression was used to identify risk factors for recurrent disease in patients with primary colon and rectal cancer. Moreover, overall survival (OS) after diagnosis of recurrent colorectal cancer was estimated.Median clinical follow-up was 58 months (Q1-Q3: 22-62). Five-year cumulative incidence of recurrent disease was 21.6% [95% confidence interval (CI): 20.0-23.2] and 30.0% (95% CI: 28.3-33.5) for patients with primary colon and rectal cancer, respectively. Stage III disease and incomplete resection margin in patients with primary colon cancer and extramural vascular invasion in patients with primary rectal cancer were strongly (HR ≥ 2) associated with recurrent disease. Median OS of patients with distant, locoregional, or the synchronous combination of distant and locoregional recurrent disease was 29, 27, and 13 months, respectively (P < 0.001). Patients with distant recurrences limited to liver or lung showed a median OS of 46 and 48 months, respectively. The incidence of recurrent disease was higher in patients with rectal cancer than in patients with colon cancer, predominantly due to higher rates of distant recurrences. OS after recurrent disease was impaired, but subgroups of patients diagnosed with recurrent disease limited to one site showed statistically significantly longer OS.

SIGNIFICANCE

Population-based data on recurrent colorectal cancer are rare, but crucial for counseling patients and their physicians. This large nationwide, population-based study provides an up-to-date overview of the epidemiology of recurrent disease in patients with stage II and III primary colon and rectal cancer treated with surgical resection.

Abandonment of Routine Radiotherapy for Nonlocally Advanced Rectal Cancer and Oncological Outcomes

Importance

Neoadjuvant short-course radiotherapy was routinely applied for nonlocally advanced rectal cancer (cT1-3N0-1M0 with >1 mm distance to the mesorectal fascia) in the Netherlands following the Dutch total mesorectal excision trial. This policy has shifted toward selective application after guideline revision in 2014.

Objective

To determine the association of decreased use of neoadjuvant radiotherapy with cancer-related outcomes and overall survival at a national level.

Design, Setting, and Participants

This multicenter, population-based, nationwide cross-sectional cohort study analyzed Dutch patients with rectal cancer who were treated in 2011 with a 4-year follow-up. A similar study was performed in 2021, analyzing all patients that were surgically treated in 2016. From these cohorts, all patients with cT1-3N0-1M0 rectal cancer and radiologically unthreatened mesorectal fascia were included in the current study. The data of the 2011 cohort were collected between May and October 2015, and the data of the 2016 cohort were collected between October 2020 and November 2021. The data were analyzed between May and October 2022.

Main Outcomes and Measures

The main outcomes were 4-year local recurrence and overall survival rates.

Results

Among the 2011 and 2016 cohorts, 1199 (mean [SD] age, 68 [11] years; 430 women [36%]) of 2095 patients (57.2%) and 1576 (mean [SD] age, 68 [10] years; 547 women [35%]) of 3057 patients (51.6%) had cT1-3N0-1M0 rectal cancer and were included, with proportions of neoadjuvant radiotherapy of 87% (2011) and 37% (2016). Four-year local recurrence rates were 5.8% and 5.5%, respectively (P = .99). Compared with the 2011 cohort, 4-year overall survival was significantly higher in the 2016 cohort (79.6% vs 86.4%; P < .001), with lower non-cancer-related mortality (13.8% vs 6.3%; P < .001).

Conclusions and Relevance

The results of this cross-sectional study suggest that an absolute 50% reduction in radiotherapy use for nonlocally advanced rectal cancer did not compromise cancer-related outcomes at a national level. Optimizing clinical staging and surgery following the Dutch total mesorectal excision trial has potentially enabled safe deintensification of treatment.

Stoma-free Survival After Rectal Cancer Resection With Anastomotic Leakage: Development and Validation of a Prediction Model in a Large International Cohort

OBJECTIVE

To develop and validate a prediction model (STOMA score) for 1-year stoma-free survival in patients with rectal cancer (RC) with anastomotic leakage (AL).

BACKGROUND

AL after RC resection often results in a permanent stoma.

METHODS

This international retrospective cohort study (TENTACLE-Rectum) encompassed 216 participating centres and included patients who developed AL after RC surgery between 2014 and 2018. Clinically relevant predictors for 1-year stoma-free survival were included in uni and multivariable logistic regression models. The STOMA score was developed and internally validated in a cohort of patients operated between 2014 and 2017, with subsequent temporal validation in a 2018 cohort. The discriminative power and calibration of the models' performance were evaluated.

RESULTS

This study included 2499 patients with AL, 1954 in the development cohort and 545 in the validation cohort. Baseline characteristics were comparable. One-year stoma-free survival was 45.0% in the development cohort and 43.7% in the validation cohort. The following predictors were included in the STOMA score: sex, age, American Society of Anestesiologist classification, body mass index, clinical M-disease, neoadjuvant therapy, abdominal and transanal approach, primary defunctioning stoma, multivisceral resection, clinical setting in which AL was diagnosed, postoperative day of AL diagnosis, abdominal contamination, anastomotic defect circumference, bowel wall ischemia, anastomotic fistula, retraction, and reactivation leakage. The STOMA score showed good discrimination and calibration (c-index: 0.71, 95% CI: 0.66-0.76).

CONCLUSIONS

The STOMA score consists of 18 clinically relevant factors and estimates the individual risk for 1-year stoma-free survival in patients with AL after RC surgery, which may improve patient counseling and give guidance when analyzing the efficacy of different treatment strategies in future studies.

Clinical Validity of Tumor-Informed Circulating Tumor DNA Analysis in Patients Undergoing Surgery of Colorectal Metastases

BACKGROUND

Accurate biomarkers to monitor tumor load and response in metastatic colorectal cancer patients undergoing surgery could optimize treatment regimens.

OBJECTIVE

This study aimed to explore the clinical validity of tumor-informed quantification of circulating tumor DNA in blood using ultradeep sequencing.

DESIGN

Resection specimens from 53 colorectal cancer patients were analyzed for tumor-specific mutations in 15 genes. These mutations were used to measure the presence of circulating tumor DNA in preoperatively collected plasma samples using hybrid capture-based sequencing. Additional postoperative measurements were performed 1 week after surgery in 16 patients.

SETTINGS

The study was conducted at the Radboud University Medical Center.

PATIENTS

A total of 53 colorectal cancer patients undergoing surgery of metastases were included.

MAIN OUTCOME MEASURES

The detection of circulating tumor DNA.

RESULTS

At least 1 tumor-specific mutation was detected in all tumor samples. In preoperative plasma samples, circulating tumor DNA was detected in 88% (37/42) of systemic treatment-naïve patients and in 55% (6/11) of patients who received preoperative chemotherapy. More specifically, circulating tumor DNA was detected in 0% (0/3) of cases with a subtotal or partial pathologic response and in 75% (6/8) of cases without a pathologic response in the resection specimen ( p = 0.06). In postoperative plasma samples, circulating tumor DNA was detected in 80% (4/5) of patients with an incomplete resection and in 0% (0/11) of those with a complete resection ( p = 0.003).

LIMITATIONS

The study was limited by the heterogeneity of the cohort and the small number of postoperative plasma samples.

CONCLUSIONS

These data indicate that tumor-informed circulating tumor DNA detection in the plasma of patients undergoing surgery for metastatic colorectal cancer is feasible and may have clinical value in response monitoring and predicting residual disease. Prospective studies are needed to establish the clinical utility of circulating tumor DNA analysis to guide treatment decisions in these patients. See Video Abstract at http://links.lww.com/DCR/B990 .

VALIDEZ CLNICA DEL ANLISIS DE ADN DEL TUMOR CIRCULANTE INFORMADO POR EL TUMOR EN PACIENTES SOMETIDOS A CIRUGA DE METSTASIS COLORRECTALES

ANTECEDENTES:Los biomarcadores precisos para monitorear la carga tumoral y la respuesta en pacientes con cáncer colorrectal metastásico que se someten a cirugía podrían optimizar los regímenes de tratamiento.OBJETIVO:Este estudio explora la validez clínica de la cuantificación informada por el tumor del ADN tumoral circulante en sangre mediante secuenciación ultraprofunda.DISEÑO:Se analizaron muestras de resección de 53 pacientes con cáncer colorrectal en busca de mutaciones específicas del tumor en quince genes. Estas mutaciones se usaron para medir la presencia de ADN tumoral circulante en muestras de plasma recolectadas antes de la operación usando secuenciación basada en captura híbrida. Se realizaron mediciones postoperatorias adicionales una semana después de la cirugía en dieciséis pacientes.AJUSTES:El estudio se realizó en el centro médico de la universidad de Radboud.PACIENTES:Se incluyeron un total de 53 pacientes con cáncer colorrectal sometidos a cirugía de metástasis.PRINCIPALES MEDIDAS DE RESULTADO:La detección de ADN tumoral circulante.RESULTADOS:Se detectó al menos una mutación específica de tumor en todas las muestras de tumor. En muestras de plasma preoperatorias, se detectó ADN tumoral circulante en el 88% (37/42) de los pacientes sin tratamiento sistémico previo y en el 55% (6/11) de los pacientes que recibieron quimioterapia preoperatoria. Más concretamente, en el 0% (0/3) de los casos con respuesta patológica subtotal o parcial y en el 75% (6/8) de los casos sin respuesta patológica en la pieza de resección ( p = 0,06). En muestras de plasma postoperatorio se detectó ADN tumoral circulante en el 80% (4/5) de los pacientes con una resección incompleta y en el 0% (0/11) de los que tenían resección completa ( p = 0,003).LIMITACIONES:El estudio estuvo limitado por la heterogeneidad de la cohorte y el pequeño número de muestras de plasma postoperatorias.CONCLUSIONES:Estos datos indican que la detección de ADN tumoral circulante informado por el tumor en el plasma de pacientes sometidos a cirugía por cáncer colorrectal metastásico es factible y puede tener valor clínico en el control de la respuesta y la predicción de la enfermedad residual. Se necesitan estudios prospectivos para establecer la utilidad clínica del análisis de ADN tumoral circulante para guiar las decisiones de tratamiento en estos pacientes. Consulte Video Resumen en http://links.lww.com/DCR/B990 . (Traducción-Dr. Mauricio Santamaria ).

FOLFOXIRI + bevacizumab versus FOLFOX/FOLFIRI + bevacizumab in patients with initially unresectable colorectal liver metastases (CRLM) and right-sided and/or RAS/BRAFV600E-mutated primary tumor: Phase III CAIRO5 study of the Dutch Colorectal Cancer Group

LBA3506

Background: Patients (pts) with initially unresectable CRLM may qualify for curative-intent local therapy after downsizing by induction systemic therapy. The CAIRO5 study aims to find the optimal induction regimen. We present the results of pts with right-sided and/or RAS/ BRAFV600E mutated primary tumors. Accrual in pts with left-sided and RAS/ BRAFV600E wildtype tumors is ongoing. Methods: Pts were randomized between FOLFOX or FOLFIRI + bevacizumab (B) (arm A) and FOLFOXIRI-B (arm B), in both arms up to 12 cycles and followed by 5FU/LV/B maintenance. Prior systemic or local therapy for metastases was not allowed. Unresectability of CRLM at baseline was assessed by an online liver expert panel of surgeons and radiologists based on predefined criteria, and resectability every 2 months thereafter based on panel majority vote. The primary endpoint was progression-free survival (PFS). Secondary endpoints were R0/1 resection, overall survival, overall response rate (ORR), toxicity, pathologic response, postoperative morbidity and correlation of panel evaluations with outcome. Pts were stratified by potentially resectable vs permanently unresectable CRLM, serum LDH (normal/abnormal), BRAFV600E mutation, sidedness, choice of irinotecan vs oxaliplatin and institute. To detect a hazard ratio (HR) of 0.70 for PFS with 80% power and a 2-sided log-rank test at 5%, 257 events were required, assuming a median PFS of 8.7 months for arm A. Results: From December 2014 until March 2021, 294 pts were randomized, 148 in arm A and 146 in arm B in 43 Dutch and 1 Belgian sites. 3 ineligible pts were excluded. Median follow up was 40 months. Pts received a median of 10 vs 9 induction cycles in arm A vs B. Main characteristics were (arm A/B): median age 61/65 years, male 63.9/60.4%, right-sided primary tumor 39.5/41.7%, RAS mutant 85.7/86.1%, BRAFV600E mutant 6.8/8.3%, synchronous disease 86.4/89.6%, prior adjuvant chemotherapy 4.8/4.9%, median number of CRLM 12/12. With 259 events, median PFS in arm A vs B was 9.0 vs 10.6 months (stratified HR 0.74, 95% CI 0.57-0.96, p=0.02). ORR was 32.0% vs 52.1% (p<0.001), any grade ≥3 adverse events occurred in 58.5% vs 75.0% (p=0.003), the most frequent were neutropenia (12.9/38.2%, p<0.001), hypertension (14.3/13.9%, p=1) and diarrhea (3.4/19.4%, p<0.001) in arm A vs B, respectively. R0/1 resection ± ablation rates were 37.4% vs 51.4% (p=0.02) with 2-stage procedures in 16.4% vs 32.4% (p=0.04), postoperative complications occurred in 38.2% vs 51.2% (p=0.14), Clavien Dindo grade ≥3 in 14.7% vs 26.8% (p=0.08). Conclusions: FOLFOXIRI-B vs FOLFOX/FOLFIRI-B significantly increases PFS, ORR and R0/1 resections at the cost of increased toxicity in pts with initially unresectable CRLM and right-sided and/or RAS/ BRAFV600E mutated primary tumor. Clinical trial information: NCT02162563.

STAR-TREC phase II: Can we save the rectum by watchful waiting or transanal surgery following (chemo)radiotherapy versus total mesorectal excision for early rectal cancer?

3502

Background: No randomised trials have compared non-operative organ preservation (OP) therapy for early-stage rectal cancer versus standard of care (SoC) using total mesorectal excision (TME) alone. STAR-TREC evaluated the feasibility of recruiting to a study comparing contrasting OP therapies, optimised for treatment of early tumours, versus SoC. Methods: STAR-TREC was a prospective, randomised, open-label, feasibility study in the UK, Netherlands and Denmark. Patients with biopsy proven adenocarcinoma of the rectum, staged ≤mrT3b N0 M0, ≤40mm diameter, ECOG 0-1 were randomised in a 1:1:1 ratio to TME, OP via mesorectal short-course radiotherapy (5x5 Gy), or OP via mesorectal chemo-radiotherapy (25x2 Gy + capecitabine) (Peters FP et al. Mesorectal radiotherapy for early stage rectal cancer: A novel target volume. Clin Transl Radiat Oncol 2020; 21: 104-11). Standardised response assessment classified OP cases as complete response for no further treatment, partial response for transanal endoscopic microsurgery or poor response for TME by 20 weeks. Surveillance following OP consisted of 3-monthly endoscopy/MRI. All cases had CT thorax/abdomen/pelvis at 24 months (m). The primary outcome was recruitment rate over 2 years, with randomisation of 120 international cases calculated as sufficient to support a phase III trial. Secondary outcomes included acute toxicity, stoma and OP rates at 12m, disease free survival (DFS) and non-regrowth DFS (NRDFS) at 24m and EORTC QLQ-C30 summary score at 12 and 24m. Phase II analysis was pre-specified, approved by the data monitoring committee conditional upon grouping of OP arms to inform phase III design, without prejudicing the outcome (STAR-TREC Phase III protocol. Colorectal Disease 2022). Results: Recruitment endpoints were met on 28 Oct 2019. Key secondary outcomes are tabulated by intention to treat. No 6-month mortality occurred. Conclusions: OP pathways optimised for early tumours reduce acute surgical morbidity without introducing substantial radiation toxicity to achieve OP in 60% with no increase in NRDFS at 24m compared to SoC. Overall quality of life was evenly matched. STAR-TREC phase III will determine the optimal strategy for achieving OP (STAR-TREC Phase III protocol. Colorectal Disease 2022). Clinical trial information: NCT02945566. [Table: see text]

Immunological responses to adjuvant vaccination with combined CD1c+ myeloid and plasmacytoid dendritic cells in stage III melanoma patients

We evaluated the immunological responses of lymph-node involved (stage III) melanoma patients to adjuvant dendritic cell vaccination with subsets of naturally occurring dendritic cells (nDCs). Fifteen patients with completely resected stage III melanoma were randomized to receive adjuvant dendritic cell vaccination with CD1c⁺ myeloid dendritic cells (cDC2s), plasmacytoid dendritic cells (pDCs) or the combination. Immunological response was the primary endpoint and secondary endpoints included safety and survival. In 80% of the patients, antigen-specific CD8⁺ T cells were detected in skin test-derived T cells and in 55% of patients, antigen-specific CD8⁺ T cells were detectable in peripheral blood. Functional interferon-γ-producing T cells were found in the skin test of 64% of the patients. Production of nDC vaccines meeting release criteria was feasible for all patients. Vaccination only induced grade 1-2 adverse events, mainly consisting of fatigue. In conclusion, adjuvant dendritic cell vaccination with cDC2s and/or pDCs is feasible, safe and induced immunological responses in the majority of stage III melanoma patients.

Follow-up practice and healthcare utilisation of colorectal cancer survivors

OBJECTIVE

To examine healthcare utilisation and adherence to colorectal cancer (CRC) follow-up guidelines.

METHODS

A total of 2450 out of 3025 stage I-III CRC survivors diagnosed between 2000 and 2009 completed the Hospital Anxiety and Depression Scale, SF-12, EORTC QLQ-CR38 and Fatigue Assessment Score questionnaires, in December 2010. Multivariable regression analyses were performed to identify predictors for increased follow-up care (>1 visit than recommended by guidelines).

RESULTS

In the first follow-up year, the average number of cancer-related visits to the general practitioner and medical specialist was 1.7 and 4.2, respectively. More than 80% of the CRC survivors was comfortable with their follow-up schedule, and 49-72% of them received follow-up according to the guidelines. Around 29-47% was followed more than recommended. Simultaneously, around 4-14% of the CRC survivors received less follow-up care than recommended. Survivors of stage III disease treated with chemotherapy received the most follow-up care. In addition, lower socio-economic status stoma and fatigue were associated with increased follow-up care.

CONCLUSION

CRC survivors were predominantly followed according to national guidelines. Increased follow-up care is driven by advanced disease stage, chemotherapy, SES, stoma and fatigue. Future studies should investigate how increased follow-up care use can be reduced, while still addressing patients' needs.

Plasma metabolites associated with colorectal cancer stage: Findings from an international consortium

Colorectal cancer is the second most common cause of cancer-related death globally, with marked differences in prognosis by disease stage at diagnosis. We studied circulating metabolites in relation to disease stage to improve the understanding of metabolic pathways related to colorectal cancer progression. We investigated plasma concentrations of 130 metabolites among 744 Stages I-IV colorectal cancer patients from ongoing cohort studies. Plasma samples, collected at diagnosis, were analyzed with liquid chromatography-mass spectrometry using the Biocrates AbsoluteIDQ™ p180 kit. We assessed associations between metabolite concentrations and stage using multinomial and multivariable logistic regression models. Analyses were adjusted for potential confounders as well as multiple testing using false discovery rate (FDR) correction. Patients presented with 23, 28, 39 and 10% of Stages I-IV disease, respectively. Concentrations of sphingomyelin C26:0 were lower in Stage III patients compared to Stage I patients (pFDR  < 0.05). Concentrations of sphingomyelin C18:0 and phosphatidylcholine (diacyl) C32:0 were statistically significantly higher, while citrulline, histidine, phosphatidylcholine (diacyl) C34:4, phosphatidylcholine (acyl-alkyl) C40:1 and lysophosphatidylcholines (acyl) C16:0 and C17:0 concentrations were lower in Stage IV compared to Stage I patients (pFDR  < 0.05). Our results suggest that metabolic pathways involving among others citrulline and histidine, implicated previously in colorectal cancer development, may also be linked to colorectal cancer progression.

Multimodal fluorescence-guided surgery of colorectal peritoneal metastases, a phase I/II clinical trial

TPS4119

Background: Successful treatment of patients with colorectal peritoneal carcinomatosis highly depends on complete surgical tumor resection of all tumor. Oncological outcomes can potentially be improved by intraoperative imaging using a tumor-targeting antibody conjugated to a fluorophore and a radiotracer. This enables preoperative radionuclide imaging, real-time intraoperative fluorescence imaging and gamma detection. In this study we investigate the feasibility, accuracy and safety of CEA-targeted preoperative SPECT/CT and intraoperative fluorescence imaging in patients with colorectal PC. Methods: In this phase I/II single arm protein dose escalation study patients with peritoneal metastases of colorectal origin who are scheduled for cytoreductive surgery and HIPEC will receive an intravenous injection of the CEA-targeting tracer 111In-DOTA-labetuzumab-IRDye800CW. The first 15 patients will receive a single dose of 2,10 or 50 mg 6 to 7 days prior to surgery. Four to five days after injection SPECT/CT imaging of the thorax and abdomen is performed to determine intra-abdominal tumor load and detect extra-abdominal metatases. At day 6/7 after injection, standard cytoreductive surgical resection extended with real-time near-infrared fluorescence imaging and radio guidance is performed. After surgery, the peritoneal cavity will be re-examined for residual disease with fluorescence imaging. Resected specimens are analyzed microscopically, immunohistochemically (CEA and H&E) and by gamma counting. Blood samples are drawn for farmacokinetics and safety analysis at 180 minutes, 4 days, 6 days and 3 weeks after tracer injection. In the phase II dose expansion cohort, 14 more patients will receive the optimal dose as determined in the phase I trial. The primary objectives of the trial are to assess the safety, feasibility and accuracy of preoperative SPECT/CT and intraoperative fluorescence imaging after administration of 111In- labetuzumab-IRDye800CW in patients with peritoneal carcinomatosis of colorectal origin who will undergo cytoreductive surgery and HIPEC. The secondary objectives are to assess whether additional malignant lesions can be visualized by fluorescence imaging after cytoreductive surgery, to assess the intensity of fluorescence in malignant and non-malignant tissue, to assess the correlation between localization of the dual-labeled antibody and CEA expression in tumor and healthy tissue and to determine blood concentrations of the dual labelled antibody at several time points in patients. Clinical trial information: NCT03699332 .

Mesorectal radiotherapy for early stage rectal cancer: A novel target volume

With the introduction of population-based bowel cancer screening, rectal cancer is diagnosed at earlier stages, yet standard treatment still requires the same extensive surgery that is used for more advanced stages. Organ preserving treatment is rapidly developing and is subject of investigation in numerous clinical trials. The STAR-TREC trial is an international, multi-centre randomised trial investigating organ preservation using (chemo)radiotherapy. Patients with small mrT1-3bN0V0M0 tumours are randomized between three arms: standard TME, organ preservation with SCRT or with CRT. In this trial, the clinical target volume has been tailored to the early staged disease of the included patients. This mesorectal irradiation volume includes the mesorectum and pre-sacral lymph nodes at the level of the tumour, two centimetres below and cranially up to the S2-3 interspace level. In contrast to conventional irradiation volumes, the lateral lymph nodes and the nodes along the superior rectal artery are excluded. As a result, the dose to the bowel, bladder, anal sphincter and the neurovascular plexus in the lower pelvis is substantially decreased, especially when combined with modern irradiation techniques, such as dynamic arc therapy. These lower doses are expected to lead to decreasing acute and late toxicity and beneficial functional outcomes. The implementation of this novel target volume will be accompanied by an extensive quality assurance program in the STAR-TREC trial. We describe the rationale behind the novel, mesorectal only radiotherapy treatment used in the STAR-TREC trial specifically tailored for early stage disease, with the goal of organ preservation.

Liver Resection for Hepatic Metastases from Soft Tissue Sarcoma: A Nationwide Study

BACKGROUND

This study aims to evaluate the feasibility and safety of resection of sarcoma liver metastases, and to identify possible prognostic factors for long-term survival.

METHODS

All patients who underwent resection of liver metastases of sarcoma in the Netherlands from 1998 to 2014 were included. Study data was retrospectively collected from patient files. Survival rates were calculated using Kaplan-Meier survival analysis.

RESULTS

Some 38 patients treated in 16 hospitals were included (15 male, 23 female). The median age was 57 years (37-80 years). The most common histological subtype was leiomyosarcoma (63%). The predominant site of primary tumour was the abdomen (59%). R0 resection was achieved in 16 patients. Mortality was 3 and 16% of included patients had 1 or more complications. The median follow-up period was 18 months (range 1-161). After liver resection, 1-, 3-, and 5-year survival were 88, 54, and 42% respectively. Median overall survival was 46 months (1-161 months). One- and three-year progression-free survival (PFS) after liver resection were 54 and 19% respectively. Median PFS was 16 months (1-61 months).

CONCLUSIONS

Liver surgery for sarcoma metastases is safe and leads to a relatively good survival. The choice for surgical treatment should always be discussed in a multidisciplinary sarcoma and liver team.

Feasibility of a national expert panel to determine resectability in patients with initially unresectable colorectal cancer liver metastases (CRLM)

3562

Background: Decision on optimal treatment strategy for CRLM remains complex because uniform (un)resectability criteria are lacking. We hypothesize that the use of an expert panel can improve the identification of patients with potentially resectable CRLM. The Dutch Colorectal Cancer Group (DCCG) Expert Panel was established in conjunction with the CAIRO5 study (Huiskens J et al. BMC Cancer 2015), a multicenter, randomized, phase-3 trial, investigating optimal systemic induction treatment in patients with initially unresectable CRLM. Here, we present the feasibility of this panel. Methods: The DCCG Expert Panel consists of 13 liver surgeons and 4 radiologists. Consensus was reached on predefined (un)resectability criteria at baseline. An online platform allowed resectability-assessment by 3 surgeons in case of inter-surgeon agreement, and 5 surgeons if they disagreed. CRLM were assessed as 1) resectable 2) potentially resectable, or 3) permanently unresectable. Patients with initially unresectable CRLM were evaluated at baseline and subsequently every 2 months as long as CRLM were considered potentially resectable. Results: Overall, 397 panel evaluations in 183 patients were analyzed. Median time to panel conclusion was 7 days (IQR 5-11 days) and 204 (51%) evaluations showed inter-surgeon disagreement, with major disagreement (resectable versus permanently unresectable) in 24 (14%) and 12 (29%) evaluations after 2 and 4 months of systemic treatment. Ultimately, 84 (79%) patients with resectable CRLM underwent resection and 23 (27%) resections included portal vein embolization or 2-stage procedures. In resectable CRLM with inter-surgeon agreement versus disagreement, R0 resection was achieved in 39 (75%) versus 28 (52%) patients, p = 0.013. Median time to recurrence was similar between resections with panel agreement versus disagreement, 8 versus 6 months, p = 0.447. Conclusions: This study shows the feasibility of a national Liver Expert Panel for prospective resectability assessment of patients with initially unresectable CRLM. High inter-surgeon disagreement supports the use of a panel. We aim to further validate the panel with outcome parameters. Clinical trial information: NCT02162563.

An overview of 25 years of incidence, treatment and outcome of colorectal cancer patients

Regarding the continuous changes in the diagnostic process and treatment of colorectal cancer (CRC), it is important to evaluate long-term trends which are relevant in giving direction for further research and innovations in cancer patient care. The aim of this study was to analyze developments in incidence, treatment and survival for patients diagnosed with CRC in the Netherlands. For this population-based retrospective cohort study, all patients diagnosed with CRC between 1989 and 2014 in the Netherlands were identified using data of the nationwide population-based Netherlands Cancer Registry (n = 267,765), with follow-up until January 1, 2016. Analyses were performed for trends in incidence, mortality, stage distribution, treatment and relative survival measured from the time of diagnosis. The incidence of both colon and rectal cancer has risen. The use of postoperative chemotherapy for Stage III colon cancer increased (14-60%), as well as the use of preoperative (chemo)radiotherapy for rectal cancer (2-66%). The administration of systemic therapy and metastasectomy increased for Stage IV disease patients. The 5-year relative survival increased significantly from 53 to 62% for colon cancer and from 51 to 65% for rectal cancer. Ongoing advancements in treatment, and also improvement in other factors in the care of CRC patients-such as diagnostics, dedicated surgery and pre- and postoperative care-lead to a continuous improvement in the relative survival of CRC patients. The increasing incidence of CRC favors the implementation of the screening program, of which the effects should be monitored closely.

Incidence and origin of histologically confirmed liver metastases: an explorative case-study of 23,154 patients

Background

The liver is a common metastatic site for a large variety of primary tumors. For both patients with known and unknown primary tumors it is important to understand metastatic patterns to provide tailored therapies.

Objective

To perform a nationwide exploration of the origins of histological confirmed liver metastases.

Results

A total of 23,154 patients were identified. The majority of liver metastases were carcinomas (n=21,400; 92%) of which adenocarcinoma was the most frequent subtype (n=17,349; 75%). Most common primary tumors in patients with adenocarcinoma were from colorectal (n=8,004), pancreatic (n=1,755) or breast origin (n=1,415). In women of 50 years and younger, metastatic adenocarcinoma originated more frequently from breast cancer, while in women older than 70 years liver metastases originated more frequently from gastrointestinal tumors. Liver metastases in men older than 70 years originated often from squamous cell lung carcinoma. An unknown primary tumor was detected in 4,209 (18%) patients, although tumor type could be determined in 3,855 (92%) of them.

Methods

Data were collected using the nationwide network and registry of histo- and cytopathology in the Netherlands (PALGA). All histological confirmed liver metastases between January 2001 and December 2010 were evaluated for tumor type, origin of the primary tumor and were correlated with patient characteristics (age, gender).

Conclusion

The current study provides an overview of the origins of liver metastases in a series of 23,154 patients.

Clinical lymph node staging by imaging in colorectal cancer: A flip of the coin?

e15160

Background: Clinical lymph node staging by MRI and CT is important in stratification for neoadjuvant therapy in colorectal cancer. Overstaging may result in unnecessary neoadjuvant therapy, but understaging may refrain patients from adequate preoperative treatment. This study aims to provide insight in current daily practice in clinical lymph node staging in CRC in the Netherlands. Methods: All patients with primary CRC, diagnosed between 2003-2014, who underwent lymph node dissection were selected from the nationwide population-based Netherlands Cancer Registry (n=100,211). Trends in patient- and tumor-characteristics, and lymph node staging were analyzed. For the years 2011-2014, sensitivity, specificity, positive (PPV) and negative predictive value (NPV) were calculated for clinical lymph node staging, with histology as the gold standard. Only patients without preoperative treatment were analyzed. Since prospective studies have shown that 5x5 Gy radiotherapy (RT) followed by total mesorectal excision within 10 days does not lead to nodal downstaging, an additional analysis was performed in this group. Results: The proportion clinically positive lymph nodes increased significantly between 2003-2014; from 7% to 22% for colon cancer and from 7% to 53% for rectal cancer. The proportion histological positive lymph nodes remained fairly stable over time (±35% colon, ±33% rectum). During 2011-2014, clinical lymph node staging was available in the registry in 86% of colon cancer patients, 92% of rectal cancer patients without neoadjuvant treatment and 95% of rectal cancer patients with 5x5 Gy RT. The parameters based on data from this period are presented in table 1. Conclusions: With a sensitivity and PPV of approximately 50%, clinical lymph node staging is about as accurate as flipping a coin. This leads to overtreatment in patients with rectal cancer with neoadjuvant RT. Acceptable specificity and NPV limit the risk of undertreatment. [Table: see text]

The incidence of secondary pelvic tumors after previous (chemo)radiation for rectal cancer

491

Background: The aim of this study was to analyze the association between radiotherapy (RT) for rectal cancer and the development of second primary tumors. Methods: Data on all surgically treated, non-metastasized primary rectal cancer patients diagnosed between 1989 and 2007 were retrieved from a population-based cancer registry and retrospectively reviewed. To estimate the cumulative incidence of a second tumor, Fine and Gray’s competing risk model was used with death as a competing event. Standardized incidence ratios (SIR’s) were calculated for comparison with the incidence of primary tumors in the general population, taking in account sex, age and calendar year. Results: The cohort consisted of 29,214 patients of which 15,454 patients had undergone (chemo)RT. Median follow-up was 6.2 years (range 0-24). 3655 patients were diagnosed with at least one second primary tumor of which 808 patients had pelvic tumors. The SIR for any second tumor was 1.14 (95% confidence interval [CI] 1.10-1.17), resulting in 23.3/10,000 excess cases per year. RT reduced the cumulative incidence of second pelvic tumors compared to patients who received no RT (SHR 0.70, 95% CI 0.61-0.81). Second pelvic tumors were more common in patients who underwent post-operative RT than in patients who underwent pre-operative RT (SHR 1.37, 95% CI 1.10-1.70). Organ-specific analyses showed that second prostate tumors were less common in patients who received RT compared to patients who received no RT (SHR = 0.51, 95% CI 0.43-0.62). RT also reduced the risk for a second primary tumor in the rectum(sigmoid) compared to patients who did not receive RT (SHR 0.59 95% CI 0.37-0.94). Patients who received post-operative RT had higher chances of developing a second rectum(sigmoid) tumor then patients who received pre-operative RT (SHR 2.25, 95% CI 1.07-4.73). Patients without RT had worse overall survival than patients who received RT (hazard ratio 1.22, 95% CI 1.19-1.26). Conclusions: In this nationwide study, patients with previous rectal cancer had a slightly increased chance of developing another primary tumor compared with the general population. We found a protective effect of RT on the development of secondary pelvic tumors, predominantly for prostate cancer.

The CAIRO4 study: The role of surgery of the primary tumour with few or absent symptoms in patients with synchronous unresectable metastases of colorectal cancer—A randomized phase III study of the Dutch Colorectal Cancer Group (DCCG)

TPS782

Background: There is no consensus regarding resection of the primary tumour with few or absent symptoms in patients with synchronous unresectable metastatic colorectal cancer. A potential benefit of resection of the primary tumour is to prevent complications of the primary tumour in later stages of the disease. Retrospective studies also show a potential survival benefit for patients undergoing resection. However, surgery can cause severe morbidity and mortality in this patient group. We hereby propose a randomized trial in order to demonstrate that resection of the primary tumour improves overall survival. Methods: The CAIRO4 study is a multicentre, randomized, phase III study of the Dutch Colorectal Cancer Group (DCCG). Patients with synchronous unresectable metastases of colorectal cancer and few or absent symptoms of the primary tumour are randomized 1:1 between systemic therapy only, and resection of the primary tumour followed by systemic therapy. Patients will be stratified according to location of the primary tumour (colon versus rectum), WHO performance status (0-1 versus 2), hospital of inclusion, serum LDH (normal versus abnormal) and number of metastatic sites (single versus multiple). To demonstrate a survival benefit of 6 months in the experimental arm, a total of 218 events are needed (80% power, significance lever 0.05). Accounting for accrual time and follow-up, we need a total of 360 patients (180 patients per arm). Systemic therapy will consist of fluoropyrimidine-based chemotherapy in combination with bevacizumab. The primary objective of this study is to determine the clinical benefit in terms of overall survival of initial resection of the primary tumour. Secondary endpoints include progression free survival, surgical morbidity, quality of life and the number of patients requiring resection of the primary tumour in the control arm. Accrual has started in September 2012. As of January 2015, 64 centres in the Netherlands and Denmark are participating in the CAIRO4 study. Clinical trial information: NCT01606098.