Long-Term Outcomes After R0 Resection of Synchronous Peritoneal Metastasis from Colorectal Cancer Without Cytoreductive Surgery or Hyperthermic Intraperitoneal Chemotherapy

Conversion therapy with pembrolizumab for a peritoneal metastasis of rectal cancer causing hydronephrosis in a patient with Lynch syndrome

A 44-year-old woman with Lynch syndrome was referred to our hospital for treatment of recurrence of microsatellite instability-high rectal cancer. [18F]Fluorodeoxyglucose (18FDG)-positron emission tomography revealed a peritoneal metastasis with invasion to the small intestine and left ureter. The peritoneal metastasis was diagnosed initially as unresectable because of extensive invasion to the left ureter requiring nephrectomy. Hence, first-line treatment with pembrolizumab was started. After the first course of pembrolizumab, she developed hydronephrosis and a resulting urinary tract infection (UTI). A percutaneous nephrostomy was performed to control the UTI. After six courses of pembrolizumab, 18FDG-positron emission tomography showed that the peritoneal metastasis was smaller with significantly reduced 18FDG uptake, and it was then diagnosed as resectable without nephrectomy. She underwent R0 resection of the peritoneal metastasis with partial resection of the small intestine. Intraoperatively, the peritoneal metastasis showed no invasion of the left ureter, allowing its preservation. The percutaneous nephrostomy was removed postoperatively, and she has not developed any subsequent UTIs. Histopathologically, the tumor showed a pathological complete response to pembrolizumab. To the best of our knowledge, this is the first case of conversion therapy with pembrolizumab for peritoneal metastasis with hydronephrosis.

Cytoreductive surgery plus hyperthermic intraperitoneal chemotherapy versus R0 resection for resectable colorectal cancer with peritoneal metastases and low peritoneal cancer index scores: a collaborative observational study from Korea and Japan

BACKGROUND

The benefits of hyperthermic intraperitoneal chemotherapy (HIPEC) after cytoreductive surgery (CRS) for colorectal cancer with peritoneal metastasis (CPM) remain controversial. R0 resection without peritoneal stripping might be as effective as CRS plus HIPEC. The authors aimed to compare the long-term oncological outcomes of patients with CPM and peritoneal cancer index (PCI) scores less than or equal to 6 who underwent R0 resection in Japan with those who underwent CRS plus HIPEC in Korea.

MATERIALS AND METHODS

This international, retrospective cohort study was conducted in Korea and Japan using a prospectively collected clinical database. Patients who underwent surgery from July 2014 to December 2021 for CPM with a PCI score of less than or equal to 6 and completeness of the cytoreduction score-0 were included. The primary outcome was relapse-free survival (RFS), and the secondary outcomes were overall survival, peritoneal RFS (PRFS), and postoperative outcomes.

RESULTS

The 3-year RFS was significantly longer in the CRS+HIPEC group than in the R0 resection group: 35.9% versus 6.9% ( P <0.001); 31.0% versus 6.7% ( P =0.040) after propensity score matching. The median PRFS was significantly longer in the CRS+HIPEC group than in the R0 resection group: 24.5 months versus 17.2 months ( P =0.017). The 3-year overall survival and postoperative complications did not significantly differ between the two groups.

CONCLUSIONS

RFS and PRFS rates were significantly prolonged after CRS plus HIPEC, whereas postoperative complications and length of hospital stay were not increased. Therefore, curative CRS plus HIPEC may be considered a treatment strategy for selected patients with resectable CPM and low PCI scores.

Clinical Impact of Radical Resection of Synchronous and Metachronous Peritoneal Metastases from Colorectal Cancer

BACKGROUND

According to some case series, patients with colorectal cancer (CRC) who underwent radical resection of synchronous peritoneal metastases (PM) with the primary tumor had better survival than patients who underwent non-surgical treatment. However, little evidence exists regarding the significance of radical resection for metachronous PM.

OBJECTIVE

This study aimed to evaluate the clinical significance of surgical intervention for isolated PM from CRC, with a particular focus on time to PM.

METHODS

A total of 74 consecutive patients with isolated PM from CRC, including 40 and 34 patients with synchronous and metachronous PM, respectively, treated between 2007 and 2018 were retrospectively analyzed. The primary outcome measure was overall survival (OS) from diagnosis, and the OS was compared between radical resection and palliative chemotherapy.

RESULTS

Five-year OS was 39.7% for all patients. Patients with radical resection had significantly better 5-year OS compared with those with palliative chemotherapy (62.8% vs. 11.0%; p < 0.0001). According to time to PM, patients with radical resection had significantly better 5-year OS compared with those with palliative chemotherapy for both synchronous PM (47.6% vs. 0%; p = 0.019) and metachronous PM (77.2% vs. 15.2%; p < 0.0001). Multivariable analysis stratified by time to PM revealed that surgical intervention is a significant favorable prognostic factor only in patients with metachronous PM (hazard ratio 0.117, 95% confidence interval 0.020-0.678; p = 0.017).

CONCLUSIONS

Patients with radical resection of PM had good survival compared with those with chemotherapy alone, especially for metachronous PM. Surgical intervention should be considered for isolated metachronous PM when radical resection is feasible.

Strategic Insight into the Combination Therapies for Metastatic Colorectal Cancer

Colorectal cancer (CRC) is the second most common cause of cancer-related deaths worldwide. The 5-year survival rate after curative resection is almost 80%, however, it is still less than satisfactory for metastatic CRC (mCRC). The combination approach including surgery, chemotherapy, molecular targeted therapy, and immunotherapy is a promising strategy due to its synergistic anticancer effect. Moreover, circulating tumor DNA (ctDNA) analysis has been reported to stratify the post-operative risk of recurrence, thus providing clinically valuable information for deciding to conduct adjuvant chemotherapy. Furthermore, multiple new drugs that potentially target undruggable genes, including KRAS, have been developed. In this review, we discuss the current management of patients with mCRC and future perspectives in the light of a combination therapeutic strategy.

Intraperitoneal paclitaxel combined with FOLFOX/CAPOX plus bevacizumab for colorectal cancer with peritoneal carcinomatosis (the iPac-02 trial): study protocol of a single arm, multicenter, phase 2 study

BACKGROUND

The safety of intraperitoneally administrated paclitaxel (op PTX) was demonstrated in the phase I trial of ip PTX combined with conventional systemic chemotherapy for colorectal cancer with peritoneal carcinomatosis. Moreover, the median survival time was 29.3 months, which was longer than that observed in previous studies. Here, we planned the phase II trial of ip PTX: the iPac-02 trial.

METHODS

This multicenter, open-label, single assignment interventional clinical study includes patients with colorectal cancer with unresectable peritoneal carcinomatosis. FOLFOX-bevacizumab or CAPOX-bevacizumab is administered concomitantly as systemic chemotherapy. PTX 20 mg/m2 is administered weekly through the peritoneal access port in addition to these conventional systemic chemotherapies. The response rate is the primary endpoint. Progression-free survival, overall survival, peritoneal cancer index improvement rate, rate of negative peritoneal lavage cytology, safety, and response rate to peritoneal metastases are the secondary endpoints. A total of 38 patients are included in the study. In the interim analysis, the study will continue to the second stage if at least 4 of the first 14 patients respond to the study treatment. The study has been registered at the Japan Registry of Clinical Trials (jRCT2031220110).

RESULTS

We previously conducted phase I trial of ip PTX combined with conventional systemic chemotherapy for colorectal cancer with peritoneal carcinomatosis [1]. In the study, three patients underwent mFOLFOX, bevacizumab, and weekly ip PTX, and the other three patients underwent CAPOX, bevacizumab, and weekly ip PTX treatment. The dose of PTX was 20 mg/m [2]. The primary endpoint was the safety of the chemotherapy, and secondary endpoints were response rate, peritoneal cancer index improvement rate, rate of negative peritoneal lavage cytology, progression-free survival, and overall survival. Dose limiting toxicity was not observed, and the adverse events of ip PTX combined with oxaliplatin-based systemic chemotherapy were similar to those described in previous studies using systemic chemotherapy alone [3, 4]. The response rate was 25%, peritoneal cancer index improvement rate was 50%, and cytology in peritoneal lavage turned negative in all the cases. The progression-free survival was 8.8 months (range, 6.8-12 months), and median survival time was 29.3 months [5], which was longer than that observed in previous studies.

CONCLUSION

Here, we planned the phase II trial of ip paclitaxel combined with conventional chemotherapy for colorectal cancer with peritoneal carcinomatosis: the iPac-02 trial.

Development and validation of a meta-learning-based multi-modal deep learning algorithm for detection of peritoneal metastasis

PURPOSE

The existing medical imaging tools have a detection accuracy of 97% for peritoneal metastasis(PM) bigger than 0.5 cm, but only 29% for that smaller than 0.5 cm, the early detection of PM is still a difficult problem. This study is aiming at constructing a deep convolution neural network classifier based on meta-learning to predict PM.

METHOD

Peritoneal metastases are delineated on enhanced CT. The model is trained based on meta-learning, and features are extracted using multi-modal deep Convolutional Neural Network(CNN) with enhanced CT to classify PM. Besides, we evaluate the performance on the test dataset, and compare it with other PM prediction algorithm.

RESULTS

The training datasets are consisted of 9574 images from 43 patients with PM and 67 patients without PM. The testing datasets are consisted of 1834 images from 21 testing patients. To increase the accuracy of the prediction, we combine the multi-modal inputs of plain scan phase, portal venous phase and arterial phase to build a meta-learning-based multi-modal PM predictor. The classifier shows an accuracy of 87.5% with Area Under Curve(AUC) of 0.877, sensitivity of 73.4%, specificity of 95.2% on the testing datasets. The performance is superior to routine PM classify based on logistic regression (AUC: 0.795), a deep learning method named ResNet3D (AUC: 0.827), and a domain generalization (DG) method named MADDG (AUC: 0.834).

CONCLUSIONS

we proposed a novel training strategy based on meta-learning to improve the model's robustness to "unseen" samples. The experiments shows that our meta-learning-based multi-modal PM predicting classifier obtain more competitive results in synchronous PM prediction compared to existing algorithms and the model's improvements of generalization ability even with limited data.

The efficient circulating immunoscore predicts prognosis of patients with advanced gastrointestinal cancer

Background

Immunoscore from tumor tissues was initially established to evaluate the prognosis of solid tumor patients. However, the feasibility of circulating immune score (cIS) for the prognosis of advanced gastrointestinal cancers (AGC) has not been reported.

Material and methods

Peripheral venous blood was collected from 64 untreated AGC patients. We utilized flow cytometry to determine several immune cell subpopulations, including CD8⁺ and CD4⁺ T cells, NK cells, and CD4 + CD25 + CD127^low Tregs. The circulating immune score 1 (cIS1) was assessed according to the proportions of CD4⁺, CD8⁺ T cells, and NK cell, whereas circulating immune score 2 (cIS2) was derived from the proportions of CD4⁺, CD8⁺ T cell, and CD4 + CD25 + CD127^low Tregs. The prognostic role of cIS for progression-free survival (PFS) and overall survival (OS) was analyzed using Kaplan–Meier curves and Cox multivariate models. Receiver operating characteristic (ROC) curves were depicted to compare the prognostic values of cIS1 and cIS2.

Results

AGC patients with high cIS1(≥ 2) and cIS2(≥ 2) had significantly longer PFS (cIS1: median PFS, 11 vs. 6.7 months, P = 0.001; cIS2: 12 vs. 5.8 months, P < 0.0001) and OS (cIS1: median OS, 12 vs. 7.9 months, P = 0.0004; cIS2: 12.8 vs. 7.4 months, P < 0.0001) than those with low cIS1 and low cIS2. The areas under ROC curves (AUROCs) of cIS1 and cIS2 for OS were 0.526 (95% confidence interval; 95% CI 0.326–0.726) and 0.603 (95% CI 0.427–0.779, P = 0.332), whereas AUROC of cIS2 for PFS was larger than that of cIS1 0.735 (95% CI 0.609–0.837) vs 0.625 (95% CI 0.495–0.743) (P = 0.04)).

Conclusion

The cIS can be applied to predict the prognosis of untreated AGC patients. Compared with cIS1, cIS2 displayed superior prognostic value for PFS prediction.

Is Surgical Treatment Effective or Contraindicated in Patients with Colorectal Cancer Liver Metastases Exhibiting Extrahepatic Metastasis?

BACKGROUND

Surgical resection for patients with hepatic and extrahepatic colorectal metastases remains controversial. This study aimed to determine the efficacy of curative resection of distant extrahepatic metastatic lesions in patients with colorectal liver metastases (CRLM).

METHODS

From 2007 to 2019, 377 patients with CRLM were treated; of these, 323 patients underwent hepatectomy, and 54 patients with extrahepatic metastases (EHM) had received only chemotherapy. Survival and recurrence were compared between patients with and without EHM. Variables potentially associated with survival were analyzed in univariate and multivariate analyses.

RESULTS

Among patients who underwent hepatectomy, the median, 3-, and 5-year overall survival rates for patients with EHM (n = 60) were 32 months, 47%, and 28%, respectively, while those for patients without EHM (n = 263) were 115 months, 79%, and 66%, respectively (p < 0.001). Furthermore, outcomes were similar in R2 patients with EHM and those with unresectable tumors. However, outcomes were significantly better in the R0/1 group than in the R2 and unresectable groups (p < 0.001). Among patients with EHM, multivariate analysis revealed that higher clinical risk score, incomplete resection of all EHM, extrahepatic disease detected intraoperatively, and previous treatment with neoadjuvant chemotherapy were independently associated with worse survival.

CONCLUSIONS

In patients with CRLM with EHM (liver + one organ), gross curative resection is necessary when surgical treatment is contemplated, and resection of liver metastases should be performed in patients with CRLM with smaller and fewer tumors (e.g., H1).

Lymphocyte-to-C-Reactive Protein Ratio Is the Most Sensitive Inflammation-Based Prognostic Score in Patients With Unresectable Metastatic Colorectal Cancer

BACKGROUND

Systemic inflammation contributes to the progression of malignancies. The preoperative lymphocyte-to-C-reactive protein ratio has recently been shown to predict survival of patients with colorectal cancer who undergo surgery, but its prognostic value remains unclear in patients with unresectable metastatic colorectal cancer.

OBJECTIVE

This study aimed to examine the prognostic values of inflammation-based prognostic scores in patients with metastatic colorectal cancer, focusing on the lymphocyte-to-C-reactive protein ratio.

DESIGN

This is a retrospective study from a prospectively collected database.

SETTINGS

This study was conducted at a high-volume multidisciplinary tertiary cancer center in Japan.

PATIENTS

The subjects were 756 consecutive patients with unresectable metastatic colorectal cancer who received systemic chemotherapy from 2000 to 2015. The prognostic value of the lymphocyte-to-C-reactive protein ratio was evaluated by univariable and multivariable analyses. Time-dependent receiver operating characteristics curve analysis was conducted to compare the prognostic impact of the lymphocyte-to-C-reactive protein ratio with the impact of the neutrophil-to-lymphocyte ratio, platelet-to-lymphocyte ratio, lymphocyte-to-monocyte ratio, or the modified Glasgow Prognostic Score.

MAIN OUTCOME MEASURES

The primary outcomes measured were the correlations of prognostic scores with overall survival.

RESULTS

Median survival times of patients with high, intermediate, and low lymphocyte-to-C-reactive protein ratios were 29.4, 19.3, and 13.1 months (p < 0.001). In all subgroups according to key prognostic factors (performance status, use of targeted agents, pretreatment CEA levels, tumor sidedness, M category, and primary tumor resection), patient prognosis could be clearly stratified into 3 groups by the lymphocyte-to-C-reactive protein ratio. Multivariable analysis revealed that decreased lymphocyte-to-C-reactive protein ratio was independently associated with reduced survival (low vs high: HR 1.96, p < 0.001; intermediate vs high: HR 1.44, p < 0.001). The time-dependent receiver operating characteristics curve analysis revealed that the lymphocyte-to-C-reactive protein ratio was the most sensitive predictor of survival among all inflammation-based prognostic scores on a continuous basis.

LIMITATIONS

This study was retrospective in nature.

CONCLUSIONS

The lymphocyte-to-C-reactive protein ratio is a useful prognostic biomarker for unresectable metastatic colorectal cancer and could contribute to accurate prognostication and therapeutic decision making. See Video Abstract at http://links.lww.com/DCR/B600.

RELACIN ENTRE LINFOCITOS Y PROTENA C ES EL SCORE PRONOSTICO INFLAMATORIO MAS SENSIBLE EN PACIENTES CON CNCER COLORRECTAL METASTSICO IRRESECABLE

ANTECEDENTES:La inflamación sistémica contribuye en la progresión de neoplasias malignas. Recientemente se ha demostrado que la proporción preoperatoria de linfocitos -proteína C reactiva predice la supervivencia de los pacientes con cáncer colorrectal que se sometieron a cirugía, pero su valor pronóstico sigue sin estar claro en pacientes con cáncer colorrectal metastásico irresecable.OBJETIVO:Evaluar el valor pronostico de los scores inflamtorios centrandose en linfocito- proteina c reactiva en pacientes con cáncer colorrectal metastásico.DISEÑO:Estudio retrospective evaluando una base de datos.AJUSTE:Este estudio se llevó a cabo en un centro oncológico terciario multidisciplinario de gran volumen en Japón.PACIENTES:Se incluyeron 756 pacientes consecutivos todos con cáncer colorrectal metastásico irresecable que recibieron quimioterapia sistémica de 2000 a 2015. El valor pronóstico de la proteína C reactiva se evaluó mediante análisis univariables y multivariables. Se realizó análisis de la curva de características operativas del receptor dependiente del tiempo para comparar el impacto pronóstico de la proteína linfocito-C-reactiva con el de la proporción de neutrófilos a linfocitos, la proporción de plaquetas a linfocitos, la proporción de linfocitos a monocitos o la proporción de puntuación pronóstica segun escala de Glasgow modificada.PRINCIPALES MEDIDAS DE RESULTADO:Correlacion de las puntuaciones pronósticas con la supervivencia global.RESULTADOS:La mediana de supervivencia de los pacientes con niveles altos, intermedios y bajos de proteína C reactiva de linfocitos fue de 29,4, 19,3 y 13,1 meses, respectivamente (p <0,001). En todos los subgrupos de acuerdo con los factores pronósticos clave (estado funcional, uso de agentes dirigidos, niveles de antígeno carcinoembrionario antes del tratamiento, lado del tumor, categoría M y resección del tumor primario), el pronóstico del paciente podría estratificarse claramente en tres grupos por linfocito a C- proteína reactiva. El análisis multivariable reveló que la disminución de linfocitos a proteína C reactiva se asoció de forma independiente con una supervivencia reducida (baja frente a alta: cociente de riesgo 1,96, p <0,001; intermedio frente a alto: cociente de riesgo 1,44, p <0,001). El análisis de la curva de características operativas del receptor dependiente del tiempo reveló que de linfocito a proteína C reactiva era el predictor de supervivencia más sensible entre todas las puntuaciones de pronóstico basadas en inflamación de forma continua.LIMITACIONES:Este estudio fue de naturaleza retrospectiva.CONCLUSIONES:La proteína C reactiva de linfocitos a C es un biomarcador pronóstico útil para el cáncer colorrectal metastásico irresecable y podría contribuir a un pronóstico preciso y a la toma de decisiones terapéuticas. Consulte Video Resumen en http://links.lww.com/DCR/B600.

Comparison of model fit and discriminatory ability of M category as defined by the 7th and 8th editions of the tumor-node-metastasis classification of colorectal cancer and the 9th edition of the Japanese classification

Background

In transitioning from the 7th edition of the tumor‐node‐metastasis classification (TNM‐7) to the 8th edition (TNM‐8), colorectal cancer with peritoneal metastasis was newly categorized as M1c. In the 9th edition of the Japanese Classification of colorectal, appendiceal, and anal carcinoma (JPC‐9), M1c is further subdivided into M1c1 (without other organ involvement) and M1c2 (with other organ involvement). This study aimed to compare the model fit and discriminatory ability of the M category of these three classification systems, as no study to date has made this comparison.

Methods

The study population consisted of stage IV colorectal cancer patients who were referred to the National Cancer Center Hospital from 2000 to 2017. The Akaike information criterion (AIC), Harrell's concordance index (C‐index), and time‐dependent receiver operating characteristic (ROC) curves were used to compare the three classification systems. Subgroup analyses, stratified by initial treatment year, were also performed.

Results

According to TNM‐8, 670 (55%) patients had M1a, 273 (22%) had M1b, and 279 (23%) had M1c (87 M1c1 and 192 M1c2 using JPC‐9) tumors. Among the three classification systems, JPC‐9 had the lowest AIC value (JPC‐9: 10546.3; TNM‐7: 10555.9; TNM‐8: 10585.5), highest C‐index (JPC‐9: 0.608; TNM‐7: 0.598; TNM‐8: 0.599), and superior time‐dependent ROC curves throughout the observation period. Subgroup analyses were consistent with these results.

Conclusions

While the revised M category definition did not improve model fit and discriminatory ability from TNM‐7 to TNM‐8, further subdivision of M1c in JPC‐9 improved these parameters. These results support further revisions to M1 subcategories in future editions of the TNM classification system.

A 77-Year-Old Man with a Pulse Granuloma of the Descending Colon Identified by Fluorodeoxyglucose-Positron Emission Tomography (FDG-PET) Imaging 19 Months Following Surgical Resection for Rectal Carcinoma

Patient: Male, 77-year-old

Final Diagnosis: Pulse granuloma

Symptoms: None

Medication:—

Clinical Procedure: —

Specialty: Gastroenterology and Hepatology • Oncology

The Characteristics of 206 Long-Term Survivors with Peritoneal Metastases from Colorectal Cancer Treated with Curative Intent Surgery: A Multi-Center Cohort from PSOGI

Simple Summary

Cytoreductive surgery (CRS) combined with hyperthermic intraperitoneal chemotherapy improves survival in selected patients with peritoneal metastases from colorectal cancer (CRC). However, the characteristics of long-term survivors are not well documented. This study set out to investigate the patient characteristics associated with the long-term survival of peritoneal metastases from CRC. We retrospectively analyzed 206 long-term survivors who underwent CRS for peritoneal metastases from CRC. We found that most long-term survivors showed low peritoneal cancer index (PCI), low PCI of small bowel subsets, and complete cytoreduction (CC-0), while some exhibited characteristics considered associated with poor prognosis.

Abstract

Background: We conducted this study to review the patient characteristics associated with long-term survival in patients with peritoneal metastases from colorectal cancer who underwent cytoreductive surgery (CRS). Methods: We retrospectively investigated patients with peritoneal metastases from CRC treated with curative intent surgery with or without hyperthermic intraperitoneal chemotherapy at 13 institutions worldwide between January 1985 and April 2015 and survived longer than five years after the first CRS for peritoneal metastases. Clinical and oncological features and therapeutic parameters were described and analyzed. Results: Two hundred six long-term survivors were available for study. The median peritoneal cancer index (PCI) of this cohort was 4 (interquartile range (IQR), 2–7), and the median score of the small bowel regions of the PCI (SB-PCI) was 0 (IQR, 0–2). Complete cytoreduction (CC-0) was achieved in 180 (87.4%) patients. Recurrence was observed in 122 (59.2%) patients at a median of 1.8 (IQR, 1.2–2.6) years. Conclusions: While most long-term survivors showed low PCI/SB-PCI and CCR-0, some had characteristics considered associated with poor prognosis. Curative intent treatments may be considered in well-informed and fit patients showing negative factors affecting survival outcome.

Hypochlorous acid selectively promotes toxicity and the expression of danger signals in human abdominal cancer cells

Tumors of the abdominal cavity, such as colorectal, pancreatic and ovarian cancer, frequently metastasize into the peritoneum. Large numbers of metastatic nodules hinder curative surgical resection, necessitating lavage with hyperthermic intraperitoneal chemotherapy (HIPEC). However, HIPEC not only causes severe side effects but also has limited therapeutic efficacy in various instances. At the same time, the age of immunotherapies such as biological agents, checkpoint‑ inhibitors or immune‑cell therapies, increasingly emphasizes the critical role of anticancer immunity in targeting malignancies. The present study investigated the ability of three types of long‑lived reactive species (oxidants) to inactivate cancer cells and potentially complement current HIPEC regimens, as well as to increase tumor cell expression of danger signals that stimulate innate immunity. The human abdominal cancer cell lines HT‑29, Panc‑01 and SK‑OV‑3 were exposed to different concentrations of hydrogen peroxide (H2O2), hypochlorous acid (HOCl) and peroxynitrite (ONOO‑). Metabolic activity was measured, as well as determination of cell death and danger signal expression levels via flow cytometry and detection of intracellular oxidation via high‑content microscopy. Oxidation of tumor decreased intracellular levels of the antioxidant glutathione and induced oxidation in mitochondria, accompanied by a decrease in metabolic activity and an increase in regulated cell death. At similar concentrations, HOCl showed the most potent effects. Non‑malignant HaCaT keratinocytes were less affected, suggesting the approach to be selective to some extent. Pro‑immunogenic danger molecules were investigated by assessing the expression levels of calreticulin (CRT), and heat‑shock protein (HSP)70 and HSP90. CRT expression was greatest following HOCl and ONOO‑ treatment, whereas HOCl and H2O2 resulted in the greatest increase in HSP70 and HSP90 expression levels. These results suggested that HOCl may be a promising agent to complement current HIPEC regimens targeting peritoneal carcinomatosis.

Individual learning curve of cytoreductive surgery for peritoneal metastasis from colorectal cancer: A process with an impact on survival

BACKGROUND

This study aimed to assess the learning curve (LC) of cytoredutive surgery (CRS) of peritoneal metastasis (PM) from colorectal cancer (CRC). Information about learning curves is important for developing teaching tools and well-structured training programs for the implementation of this complex procedure in new healthcare centers. The aim of this study was to estimate how many procedures an inexperienced surgeon must perform (the length of the learning period) in order to demonstrate an acceptably low rate of locoregional recurrence.

METHODS

All consecutive 74 patients with CRS for CRC performed by a novice surgeon between 2012 and 2017 in a tertiary cancer center were included. The learning curve was calculated by a cumulative sum control chart (CUSUM) graph. Two groups were formed based on the length of the learning period and were compared on overall and disease free survival.

RESULTS

The risk of locoregional recurrence decreased after surgeons had performed 19 cases, suggesting a learning period of this length. Overall survival and postoperative morbidity were not significantly different between learning and proficiency periods. Multiple linear regression analysis showed that the learning period and peritoneal cancer index are the only factors affecting disease free survival. A second learning period was observed in cases where patient care became more complex.

CONCLUSIONS

This study confirms that learning period has negative impacts on disease-free survival. An initial experience supervised in specialized centers allow to have a short learning curve for CRS for peritoneal metastases for CRC.

The role of cytoreductive surgery and hyperthermic intraperitoneal chemotherapy in the treatment of peritoneal carcinomatosis: a systematic review including evidence from Japan

The prognosis of peritoneal carcinomatosis is poor. However, the emergence of cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS + HIPEC) as a treatment option has prolonged survival and it can even potentially cure patients with peritoneal carcinomatosis. Randomized controlled studies and other observational studies indicated that this combined therapy potentially improved the prognosis of patients with colon, gastric, and ovarian cancers with acceptable morbidity and mortality rates. Even in rarer diseases, such as pseudomyxoma peritonei and malignant peritoneal mesothelioma, CRS + HIPEC markedly improved the prognoses over those with conventional treatment. Based on the accumulated evidence, clinical guidelines recommend CRS + HIPEC for selected patients with peritoneal carcinomatosis. However, several issues still need to be overcome. A standard method for HIPEC has not yet been established. Furthermore, the criteria employed for patient selection need to be clarified to achieve real benefits. The peritoneal cancer index, chemo-sensitivity and several biological markers are considered to be key factors.

Investigation of the Japanese Classification of Peritoneal Metastasis from Colorectal Cancer Referring to the Correlation with PCI

Objectives:

In Japan, there are three grades of peritoneal metastasis from colorectal cancer. The grade depends on the extent and number of lesions (P classification). The P classification is useful for its simplicity but lacks objectivity. On the other hand, the peritoneal cancer index (PCI) objectively indicates the peritoneal metastasis grade. However, the evaluation process is complicated clinically. In this study, we compared these two methods and investigated how to improve the P classification's objectivity by referring to PCI.

Methods:

We investigated 150 cases of synchronous peritoneal metastasis from colorectal cancer. We inspected the correlation between the P classification and the PCI and pointed out the problems which prevented objective evaluation when using the P classification. We also estimated new criteria for extent and number in the P classification.

Results:

We found the ideal definition for the best alignment between the P classification and the PCI was:

・P1 is metastases confined to one peritoneal region,

・P2 is 19 or fewer peritoneal metastases in two or more regions, and

・P3 is 20 or more metastases in two or more regions.

This revision improved the P classification's objectivity and correlated with the PCI.

Conclusions:

Grading using the P classification was both imprecise and subjective. We propose a new standard value of extent and number in the P classification based on the PCI. This improvement would provide an objective, simple method of grading for peritoneal metastasis from colorectal cancer.

Impact of Surgical Resection on Metachronous Metastases of Colorectal Cancer According to Tumor Doubling Time

BACKGROUND/AIM

We aimed to elucidate the prognostic impact of tumor doubling time (DT) and radical surgery when classified by DT in patients with metachronous liver, lung, or peritoneal metastases of colorectal cancer (CRC).

PATIENTS AND METHODS

We reviewed the data of 1941 patients who underwent curative surgery for CRC and calculated DT for recurrences using computed tomography.

RESULTS

Short DT was an independent prognostic risk factor in liver (p<0.001) and peritoneal (p=0.03) metastases. Survival was significantly better in patients who underwent surgery than in those who did not, both in short and long DT groups in any metastatic organ (p<0.01). Patients with long DT gained significantly better prognostic benefit from surgery than those with short DT in liver (p=0.01) and peritoneal (p=0.04) metastases.

CONCLUSION

Surgery is recommended for resectable metastases, especially in patients with liver and peritoneal metastases with long DT.

Prognostic Impact of Curative Resection for Peritoneal Recurrence of Colorectal Cancer

BACKGROUND

Peritoneal recurrence (PR) of colorectal cancer is a poor prognostic factor but may be treatable by curative resection. We investigated the efficacy of this treatment and identified risk factors for postoperative recurrence.

METHODS

The subjects were patients who underwent radical surgery for colorectal cancer between January 2006 and March 2014. Those with PR were retrospectively reviewed. Prognostic factors for overall survival (OS) and risk factors for postoperative recurrence were identified.

RESULTS

Among 2256 patients, 66 had PR (2.9%). Surgical resection of PR was performed in 41 patients. Curative resection was achieved macroscopically in 38 cases without diffuse metastases in the peritoneum distant from the primary tumor and with a peritoneal cancer index < 10. In multivariate analysis, curative resection was a significant prognostic factor [hazard ratio (HR) 0.198] for better 5-year OS compared with cases without curative resection (68.7% vs. 6.3%, P < 0.001). In 28 cases with concurrent metastasis, curative resection significantly improved 5-year OS compared with no curative resection (78.7% vs. 0%, P = 0.008). In the 38 patients with curative resection, the 3-year recurrence-free survival rate was 21.4%. In multivariate analysis, concurrent metastasis was a significant risk factor [HR 3.394] for postoperative recurrence, and cases with concurrent metastasis more frequently had recurrence within 2 years after curative resection.

CONCLUSIONS

Curative resection improved the prognosis in patients with limited and resectable PR of colorectal cancer with or without concurrent metastasis. However, recurrence after curative resection was common and concurrent metastasis was a risk factor for this recurrence.

Surgical Resection of Colorectal Cancer With Distant Metastases to Other than Liver or Lung

BACKGROUND/AIM

If both distant metastases and the primary tumour of colorectal cancer (CRC) are resectable, resection of the distant metastases is considered. The aim of this retrospective study was to determine the efficacy of curative resection of both primary and metastatic lesions in organs other than liver or lung in CRC patients.

PATIENTS AND METHODS

The medical records of 23 CRC patients who received R0 resection for primary and metastatic regions between 2009 and 2018 were retrospectively analyzed.

RESULTS

The 3-year overall survival (OS) in all 23 cases was 80.0%. There was no clinicopathological factor associated with OS on univariate analysis.

CONCLUSION

Curative surgical resection appears to be useful for distant CRC metastases to organs other than liver or lung.

Extent of Peritoneal Resection for Peritoneal Metastases: Looking Beyond a Complete Cytoreduction

Completeness of cytoreduction is one of the most important prognostic factors impacting outcomes of cytoreductive surgery (CRS). To what extent the surrounding normal peritoneum needs to be removed is not known. We hypothesized that the extent of peritoneal resection should be different for different tumors and performed this study to find evidence to support this rationale. To determine the extent of resection of surrounding tissue for any tumor, the mechanisms of tumor development and spread, tumor morphology, the possibility of finding disease in the surrounding normal tissue, and the pattern of lymph node metastases should be known. Surgical resections also depend on patterns of recurrence and the impact of varying extent of resection on survival. We performed a review of literature pertaining to pathways and patterns of peritoneal cancer spread to determine the scientific basis for the extent of peritonectomy. We also reviewed studies comparing less and more extensive peritoneal resection. There is no consensus on the extent of lymphadenectomy required for most PM. Based on this review, we provide recommendations for the extent of peritoneal resection and the extent of lymph node dissection that should be performed for some common peritoneal tumors and identify areas that require further research. We propose that a systematic method of synoptic reporting of pathological specimens of CRS should be developed to capture information regarding the disease distribution within the peritoneal cavity and morphology of PM from different tumors. This can in future be used to establish standard guidelines for such resections.

The importance of synchronicity in the management of colorectal peritoneal metastases with cytoreductive surgery and hyperthermic intraperitoneal chemotherapy

Background

Colorectal peritoneal metastases (CPM) occur in up to 13% of patients with colorectal cancer, presenting either synchronously or metachronously. Cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS and HIPEC) have been increasingly utilised for selected CPM patients with favourable outcomes, though its benefits may differ for synchronous (s-CPM) and metachronous CPM (m-CPM).

Methods

A retrospective analysis of CPM patients treated with CRS and HIPEC at the National Cancer Centre Singapore over 15 years was performed. In the s-CPM group, CPM was diagnosed at primary presentation with CRS and HIPEC performed at the time of or within 6 months from primary surgery. In the m-CPM group, patients developed CPM > 6 months after primary curative surgery.

Results

One hundred two patients with CPM were treated with CRS and HIPEC. Twenty (19.6%) patients had s-CPM and 82 (80.4%) had m-CPM. Recurrences occurred in 45% of s-CPM and in 54% of m-CPM (p = 0.619). Median overall survival was significantly prolonged in patients with m-CPM (45.2 versus 26.9 months, p = 0.025). In a subset of m-CPM patients with limited PCI in whom ICU stay was not required, a survival advantage was seen (p = 0.031).

Conclusion

A survival advantage was seen a subset of m-CPM patients, possibly representing differences in disease biology.

Identification of Two Kinase Inhibitors with Synergistic Toxicity with Low-Dose Hydrogen Peroxide in Colorectal Cancer Cells in vitro

Colorectal carcinoma is among the most common types of cancers. With this disease, diffuse scattering in the abdominal area (peritoneal carcinosis) often occurs before diagnosis, making surgical removal of the entire malignant tissue impossible due to a large number of tumor nodules. Previous treatment options include radiation and its combination with intraperitoneal heat-induced chemotherapy (HIPEC). Both options have strong side effects and are often poor in therapeutic efficacy. Tumor cells often grow and proliferate dysregulated, with enzymes of the protein kinase family often playing a crucial role. The present study investigated whether a combination of protein kinase inhibitors and low-dose induction of oxidative stress (using hydrogen peroxide, H₂O₂) has an additive cytotoxic effect on murine, colorectal tumor cells (CT26). Protein kinase inhibitors from a library of 80 substances were used to investigate colorectal cancer cells for their activity, morphology, and immunogenicity (immunogenic cancer cell death, ICD) upon mono or combination. Toxic compounds identified in 2D cultures were confirmed in 3D cultures, and additive cytotoxicity was identified for the substances lavendustin A, GF109203X, and rapamycin. Toxicity was concomitant with cell cycle arrest, but except HMGB1, no increased expression of immunogenic markers was identified with the combination treatment. The results were validated for GF109203X and rapamycin but not lavendustin A in the 3D model of different colorectal (HT29, SW480) and pancreatic cancer cell lines (MiaPaca, Panc01). In conclusion, our in vitro data suggest that combining oxidative stress with chemotherapy would be conceivable to enhance antitumor efficacy in HIPEC.

Verifying the M1c category of CRC: analysis of the data from a Japanese multi-institutional database

BACKGROUND/AIMS

In the TNM classification 8th edition, colorectal cancer (CRC) with peritoneal metastasis, one of the most poor prognostic factors, is classified as M1c (stage IVC), regardless of the presence/absence of other distant metastasis. Several cases with peritoneal metastasis have been successfully managed by surgical treatment; therefore, there is need to give more consideration for uniform differentiation of peritoneal metastasis. This study was aimed at verifying the classification of M1c in CRC.

MATERIALS AND METHODS

Data from a multi-institutional retrospective cohort of 2929 CRC patients who were diagnosed as having stage IV CRC from 1997 to 2007 were analyzed. Peritoneal metastasis alone was defined as M1c1 and peritoneal metastasis with other organ metastasis was defined as M1c2.

RESULTS

The 3-year OS of patients with M1c1 was significantly higher than that of patients with M1b (25.6% vs. 18.1%; HR 0.77; 95% confidence interval (CI) 0.65-0.92; p = 0.005); in particular, the prognosis of patients with M1c1 with localized peritoneal metastasis and R0 resection was equivalent to that of patients with M1a (3-year OS 40.5% vs. 39.2%, p = 0.41). On the other hand, among the stage IV cases, patients with M1c2 had a low R0 resection rate (5.9%) and the worst prognosis (3-year OS, 9.1%).

CONCLUSIONS

The prognosis of M1c1 with localized peritoneal metastasis is relatively good, and can be further improved by surgical intervention. Combined evaluation of the M1c1/2 classification with the peritoneal metastasis grade may help in establishing more individualized treatment strategies.

Japanese Society for Cancer of the Colon and Rectum (JSCCR) guidelines 2019 for the treatment of colorectal cancer

The number of deaths from colorectal cancer in Japan continues to increase. Colorectal cancer deaths exceeded 50,000 in 2016. In the 2019 edition, revision of all aspects of treatments was performed, with corrections and additions made based on knowledge acquired since the 2016 version (drug therapy) and the 2014 version (other treatments). The Japanese Society for Cancer of the Colon and Rectum guidelines 2019 for the treatment of colorectal cancer (JSCCR guidelines 2019) have been prepared to show standard treatment strategies for colorectal cancer, to eliminate disparities among institutions in terms of treatment, to eliminate unnecessary treatment and insufficient treatment and to deepen mutual understanding between healthcare professionals and patients by making these guidelines available to the general public. These guidelines have been prepared by consensuses reached by the JSCCR Guideline Committee, based on a careful review of the evidence retrieved by literature searches and in view of the medical health insurance system and actual clinical practice settings in Japan. Therefore, these guidelines can be used as a tool for treating colorectal cancer in actual clinical practice settings. More specifically, they can be used as a guide to obtaining informed consent from patients and choosing the method of treatment for each patient. Controversial issues were selected as clinical questions, and recommendations were made. Each recommendation is accompanied by a classification of the evidence and a classification of recommendation categories based on the consensus reached by the Guideline Committee members. Here, we present the English version of the JSCCR guidelines 2019.

Intra-abdominal recurrence from colorectal carcinoma: Differences and similarities between local and peritoneal recurrence

BACKGROUND

Peritoneal recurrences from colo-rectal cancer can be isolated (PR) or associated with local recurrences (LR). The purpose of this study was to analyze patterns and outcomes of LR and PR.

METHODS

Analyze from a prospective database of 108 patients treated with CCS plus HIPEC at two cancer centers between 2008 and 2015.

RESULTS

The population was divided into an LPR group (presence of LR with or without PR, n = 56) and a PR group (isolated PR, n = 52). The patients characteristics (age, sex, Charlson score, PCI) or perioperative treatments were comparable between the groups. The median number of resected organs for tumor involvement (respectively, 2 vs 1; p < 0.001), the percentage of patients with metastatic lymph nodes (LN+) from the resected specimen (respectively, 25% vs 7%; p = 0.016) and the mortality rate (respectively, 9% vs 0%; p = 0.023) were significantly higher in the LPR group. After a median follow-up of 32 (1-108) months, median overall survival was comparable between the two groups (respectively, 46 vs 42 months; p = 0.262).

CONCLUSIONS

LR is associated with a higher incidence of organ invasion, LN involvement (25%) and postoperative mortality. Optimal surgical resection of LR with systematic lymphadenectomy of invaded organs seems mandatory.

Factors affecting R0 resection of colorectal cancer with synchronous peritoneal metastases: a multicenter prospective observational study by the Japanese Society for Cancer of the Colon and Rectum

BACKGROUND

In Japan, R0 resection has been recommended for colorectal cancer patients with peritoneal metastases confined to the adjacent peritoneum and those with a few metastases to the distant peritoneum. R0 resection for M1c disease has drawn attention in Western countries and is currently considered an acceptable therapeutic option in the US National Comprehensive Cancer Network guidelines. However, clinical factors that affect the choice of R0 resection are unknown.

METHODS

This multicenter, prospective, observational study was conducted by the Japanese Society for Cancer of the Colon and Rectum. Colorectal cancer patients with synchronous peritoneal metastases were enrolled at 28 institutions in Japan from October 2012 to December 2016. To determine factors affecting R0 resection and R1 resection with intended R0 resection, stepwise logistic regression analyses were performed on clinical factors including age, sex, performance status (PS), body mass index, peritoneal cancer index (PCI) score, presence of ascites, presence of distant metastases, and primary tumor site.

RESULTS

R0/R1 resection was performed in 36 (31/5; 25%) of 146 patients. No distant metastases [odds ratio (OR) 52.9; 95% confidence interval (CI) 13.3-210.1; p < 0.0001], low PCI score (1-6) (OR 20.0; 95% CI 4.8-83.4; p < 0.0001), and high PS (0) (OR 2.40; 95% CI 0.66-8.68; p = 0.18) were independent factors affecting R0/R1 resection. PCI score and PS were also independent factors affecting R0/R1 resection in M1c patients without non-peritoneal distant metastases (n = 59).

CONCLUSION

Distant metastases, PCI score, and PS are three factors which affect R0 resection for M1c disease.

Primary Tumor Resection for Stage IV Colorectal Cancer in the Era of Targeted Chemotherapy

BACKGROUND

In the current era of targeted therapies, the benefits of resection of primary tumors in patients with unresectable stage IV colorectal cancer, specifically with regard to overall survival, are unknown.

METHODS

Our study population comprised 208 consecutive patients with unresectable stage IV colorectal cancer who received chemotherapy containing at least one molecular target agent, bevacizumab, cetuximab, and panitumumab, at the National Cancer Center Hospital from 2006 to 2013. To lessen the effects of confounding factors between two treatment groups (resection versus non-resection) such as performance status, presence of severe symptoms, M subcategories (M1a versus M1b, M1c) according to the TNM classification, primary tumor site, and CEA value, we conducted three different propensity score analyses (regression adjustment, stratification, and matching).

RESULTS

Of the 208 patients, 108 (52%) underwent resection of the primary tumor, while 100 (48%) did not. Regression adjustment revealed that resection was not associated with longer overall survival (hazard ratio of 0.70 (95% CI [0.49-1.00]; p = 0.051)). Stratification analysis of five strata revealed inconsistent results (hazard ratios ranged from 0.50 to 1.58); specifically, resection was associated with longer overall survival in four strata, but with shorter survival in one stratum. The propensity score-matched cohort (64 matched pairs) yielded a hazard ratio of 0.76 (95% CI [0.51-1.15]; p = 0.197).

CONCLUSIONS

All three analyses revealed that, in the current era of chemotherapy with target agents, primary tumor resection was only marginally influential and did not significantly improve overall survival over chemotherapy alone.

Perceptions in the management of colorectal peritoneal metastases: A bi-national survey of colorectal surgeons

Background

There is great variability in the uptake of cytoreductive surgery (CRS) with hyperthermic intraperitoneal chemotherapy (HIPEC) in the management of colorectal peritoneal metastases (CRPM) in Australia and New Zealand. This study aims to provide a snapshot of perceptions among colorectal surgeons in the management of CRPM.

Methods

A structured ten-question online survey was sent to all colorectal surgeons, with three questions on clinical experience and demographics, one on health economics and six on hypothetical clinical scenarios. Scores were collated and reported based on Likert scales.

Results

Eighty-one respondents (36.2%) completed the survey. Most surgeons (66.7%) strongly disagreed with offering CRS and HIPEC at all hospitals. The majority (87.7%) agreed that CRS and HIPEC offered a higher survival benefit than systemic chemotherapy in pseudomyxoma peritonei (PMP), and 69.1% in CRPM (comparators: 60.5% ovarian cancer, 14.8% gastric cancer). There were mixed strategies in managing low-volume, isolated peritoneal recurrences. The majority did not recommend second-look laparoscopy, but favoured operative management of Krukenberg tumours. In the presence of incidental peritoneal metastases, only 29.6% favoured biopsy only and referring the patient to a peritoneal disease centre.

Conclusions

Response rate was relatively low. In Australia and New Zealand, colorectal surgeons see a strong role for CRS and HIPEC in the management of PMP and CRPM. The role of “second look” surgery in high-risk cases is controversial and not supported. Krukenberg tumours are viewed as surgical disease. Regular updates and collaboration with peritoneal centres may help surgeons stay abreast with latest evidence in the field.

A novel intraperitoneal therapy for gastric cancer with DFP-10825, a unique RNAi therapeutic targeting thymidylate synthase, in a peritoneally disseminated xenograft model

Purpose

In advanced gastric cancer, peritoneal dissemination is a life‐threatening mode of metastasis. Since the treatment options with conventional chemotherapy remain limited, any novel therapeutic strategy that could control such metastasis would improve the outcome of treatment. We recently developed a unique RNA interference therapeutic regimen (DFP‐10825) consisting of short hairpin RNA against thymidylate synthase (TS shRNA) and cationic liposomes. The treatment with DFP‐10825 has shown remarkable antitumor activity in peritoneally disseminated human ovarian cancer–bearing mice via intraperitoneal administration. In this study, we expanded DFP‐10825 to the treatment of peritoneally disseminated gastric cancer.

Methods

DFP‐10825 was administered intraperitoneally into mice with intraperitoneally implanted human gastric cancer cells (MKN45 or NCI‐N87). Antitumor activity and host survival benefits were monitored. Intraperitoneal distribution of fluorescence‐labeled DFP‐10825 was monitored in this MKN45 peritoneally disseminated mouse model.

Results

Intraperitoneal injection of DFP‐10825 suppressed tumor growth in two peritoneally disseminated cancer models (MKN45 and NCI‐N87) and increased the survival time of the MKN45 model without severe side effects. Throughout the treatment regimen, no significant body weight loss was associated with the administration of DFP‐10825. Interestingly, after intraperitoneal injection, fluorescence‐labeled DFP‐10825 retained for more than 72 hours in the peritoneal cavity and selectively accumulated in disseminated tumors.

Conclusions

Intraperitoneal injection of DFP‐10825 demonstrated effective antitumor activity without systemic severe adverse effects via the selective delivery of RNAi molecules into disseminated tumors in the peritoneal cavity. Our current study indicates that DFP‐10825 could become an alternative option to improve the outcomes of patients with peritoneally disseminated gastric cancer.

Long-term outcomes after surgical dissection of inguinal lymph node metastasis from rectal or anal canal adenocarcinoma

Background

The 8th edition of the tumor-node-metastasis (TNM) classification classifies inguinal lymph nodes as regional lymph nodes for anal canal carcinoma but non-regional lymph nodes for rectal carcinoma. This difference might reflect the different prognosis of inguinal lymph node metastasis from anal canal carcinoma and rectal carcinoma. However, long-term outcomes of inguinal lymph node metastasis from rectal or anal canal adenocarcinoma are unclear, which we aimed to investigate in this study.

Methods

The study population included 31 consecutive patients with rectal or anal canal adenocarcinoma who underwent inguinal lymph node dissection with curative intent at the National Cancer Center Hospital from 1986 to 2017. Long-term outcomes were assessed and clinicopathologic variables analyzed for prognostic significance.

Results

Of the 31 patients, 12 patients had rectal adenocarcinoma and 19 patients had anal canal adenocarcinoma. Synchronous metastasis were observed in 14 patients and metachronous metastasis in 17 patients. After dissection of inguinal lymph node metastasis with curative intent, the 5-year overall survival rate was 55.2%, with 12 patients surviving for more than 5 years. Median survival time was 66.6 months. Multivariate analyses revealed that location of primary tumor (rectum versus anal canal) was not a prognostic factor, whereas lateral lymph node metastasis and histological findings were independent prognostic factors.

Conclusion

Given the good prognosis, inguinal lymph node metastasis in patients with rectal or anal canal adenocarcinoma appears to be regional rather than distant. If R0 resection can be achieved, inguinal lymph node dissection may be indicated for these patients.

Pathological assessment of cytoreductive surgery specimens and its unexplored prognostic potential-a prospective multi-centric study

BACKGROUND AND AIM

The grade/histological subtype is one of the most important prognostic markers in patients undergoing cytoreductive surgery (CRS). Our aim was to study other potential prognostic information that can be derived from the pathological evaluation of CRS specimens and provide a broad outline for evaluation of these.

METHODS

This prospective study (July to December 2018) included all patients undergoing cytoreductive surgery (CRS). A protocol for pathological evaluation was laid down which was based on existing practices at the participating centers and included evaluation of the pathological PCI, regional node involvement, response to chemotherapy, morphology of peritoneal metastases (PM) and distribution in the peritoneal cavity.

RESULTS

In 191 patients undergoing CRS at 4 centers, the pathological and surgical PCI differed in over 75%. Nodes in relation to peritoneal disease were positive in 13.6%. Disease in normal peritoneum adjacent to tumor nodules was seen in >50% patients with ovarian cancer and mucinous apppendiceal tumors. 23.8% of evaluated colorectal PM patients had a complete response and 25.0% ovarian cancer patients had a near complete pathological response to chemotherapy.

CONCLUSIONS

Pathological evaluation of extent and distribution of peritoneal disease differs from the surgical evaluation in majority of the patients. Lymph node involvement in relation of peritoneal disease is common. The morphological presentation of PM in ovarian cancer and mucinous appendiceal tumors merits evaluation of more extensive resections in these patients. Standardized methods of synoptic reporting of CRS specimens could help capture vital prognostic information that may in future influence how these patients are treated.

Hepatectomy for metachronous colorectal liver metastases following complete cytoreductive surgery and hyperthermic intraperitoneal chemotherapy for peritoneal metastases: a report of three cases

Background

Cytoreductive surgery (CRS) with hyperthermic intraperitoneal chemotherapy (HIPEC) for peritoneal metastasis (PM) from colorectal cancer (CRC) has been reported to substantially improve the prognosis and the quality of life of patients in comparison to systemic chemotherapy or palliative approaches. This study aimed to demonstrate the safety and feasibility of hepatectomy for metachronous liver metastases from CRC following CRS and HIPEC for PM on the basis of three case reports.

Case presentation

We describe three cases involving patients who underwent hepatectomy for metachronous liver metastases from CRC after CRS and HIPEC for PM. All patients underwent CRS and HIPEC after primary tumor resection, and hepatectomy was performed for the metachronous liver metastases after CRS and HIPEC. The hepatectomy procedures for cases 1, 2, and 3 were left hemihepatectomy and partial resection of S5, posterior sectionectomy, and left-lateral sectionectomy and partial resection of S5 and S8, respectively. Although adhesion of surrounding organs to the liver surface was observed on a broad level, dissections and hepatectomy could be performed safely. No recurrence was detected in cases 1 and 2 after hepatectomy. In case 3, liver metastases were detected from the time of the initial diagnosis of the primary tumor, and complete remission was achieved once with systemic chemotherapy. Although we performed hepatectomy for the recurrence of liver metastases after complete remission, early re-recurrence was observed after hepatectomy.

Conclusions

Hepatectomy for metachronous liver metastases after CRS and HIPEC for PM could be a multi-modality treatment option for CRC recurrence.

Introducing the eighth edition of the tumor-node-metastasis classification as relevant to colorectal cancer, anal cancer and appendiceal cancer: a comparison study with the seventh edition of the tumor-node-metastasis and the Japanese Classification of Colorectal, Appendiceal, and Anal Carcinoma

BACKGROUND

The eighth edition of the tumor-node-metastasis classification of malignant tumors updates cancer staging according to the evidence accumulated in the last 8 years since the release of the tumor-node-metastasis seventh edition. This review focuses on the new staging system.

METHODS

The eight edition was compared with the seventh edition as well as the Japanese Classification of Colorcetal, Appendiceal, and Anal carcinoma ninth edition.

RESULTS

Of colon and rectum, the tumor-node-metastasis eighth edition expands the M category. Specifically, colorectal cancer with peritoneal metastasis is newly categorized as M1c, distinguishing it from M1a (metastasis to one organ) and M1b (metastasis to more than one organ). In the ninth edition of Japanese Classification of Colorectal, Appendiceal, and Anal Carcinoma, M1c is further subdivided into M1c1 (metastasis to the peritoneum without other organ involvement) and M1c2 (metastasis to the peritoneum with other organ involvement). In the T category, the tumor-node-metastasis eighth edition excludes high-grade dysplasia (intraepithelial carcinoma) from Tis; this differs from both the tumor-node-metastasis seventh edition and the Japanese Classification of Colorectal, Appendiceal, and Anal Carcinoma ninth edition. In the N category, the tumor-node-metastasis eighth edition does not add the number of tumor deposits to the number of positive regional lymph nodes, whereas this number is added in the Japanese Classification of Colorectal, Appendiceal, and Anal Carcinoma ninth edition. The definition of anal cancer is also modified considerably in the tumor-node-metastasis eighth edition; specifically, tumors of perianal skin defined as within 5 cm of the anal margin are also classified as anal canal carcinoma, external iliac lymph nodes become regional lymph nodes, and both N2 and N3 are abolished in the N category. With regard to appendix, Tis (low-grade appendiceal mucinous neoplasma) and tumor deposit(s) are newly introduced. Finally, the tumor-node-metastasis eighth edition offers a new structure, labeled a 'prognostic factors grid', which consists of prognostic factors for survival in both colorectal and anal cancer.

CONCLUSIONS

Staging classification is updated regularly, which clinicians should always catch up with.

Physical plasma-treated saline promotes an immunogenic phenotype in CT26 colon cancer cells in vitro and in vivo

Metastatic colorectal cancer is the fourth most common cause of cancer death. Current options in palliation such as hyperthermic intraperitoneal chemotherapy (HIPEC) present severe side effects. Recent research efforts suggested the therapeutic use of oxidant-enriched liquid using cold physical plasma. To investigate a clinically accepted treatment regimen, we assessed the antitumor capacity of plasma-treated saline solution. In response to such liquid, CT26 murine colon cancer cells were readily oxidized and showed cell growth with subsequent apoptosis, cell cycle arrest, and upregulation of immunogenic cell death (ICD) markers in vitro. This was accompanied by marked morphological changes with re-arrangement of actin fibers and reduced motility. Induction of an epithelial-to-mesenchymal transition phenotype was not observed. Key results were confirmed in MC38 colon and PDA6606 pancreatic cancer cells. Compared to plasma-treated saline, hydrogen peroxide was inferiorly toxic in 3D tumor spheroids but of similar efficacy in 2D models. In vivo, plasma-treated saline decreased tumor burden in Balb/C mice. This was concomitant with elevated numbers of intratumoral macrophages and increased T cell activation following incubation with CT26 cells ex vivo. Being a potential adjuvant for HIPEC therapy, our results suggest oxidizing saline solutions to inactivate colon cancer cells while potentially stimulating antitumor immune responses.

The location of the primary colon cancer has no impact on outcomes in patients undergoing cytoreductive surgery for peritoneal metastasis

BACKGROUND

The impact of the location of colorectal cancer on patient outcomes has been reported in several settings. The objective of this study was to assess the prognostic impact of the location of the primary colon cancer among patients with colorectal cancer peritoneal metastases undergoing complete cytoreductive surgery.

METHODS

Using the prospectively maintained clinical and biological digestive peritoneal metastasis database of the BIG-RENAPE network, we identified 796 patients treated by a complete cytoreductive surgery between January 2004 and January 2017 for colorectal cancer peritoneal metastases in 16 different institutions. The 2 primary endpoints were overall survival and progression-free survival. To evaluate the impact on overall survival and progression-free survival of potential prognostic factors (including the location of the primary colorectal cancer), these factors were included in univariate and multivariate Cox proportional hazard models.

RESULTS

Right-sided colorectal cancers were more often BRAF mutated and had microsatellite instability, whereas the frequency of RAS mutation was similar between right-sided and left-sided colorectal cancers. After a median follow-up time of 3.3 years, there was no significant difference in overall survival or progression-free survival according to tumor side. The lack of effect of tumor location on overall survival and progression-free survival was consistent across subgroups.

CONCLUSION

Among patients undergoing complete cytoreductive surgery for peritoneal metastases, the site of the primary colorectal cancer was not associated with differences in progression-free survival or overall survival. Tumor side should not be used as a stratification factor in trials of colorectal cancer peritoneal metastases and should not be used in the selection process of patients for cytoreductive surgery.

Shorter survival in adolescent and young adult patients, compared to adult patients, with stage IV colorectal cancer in Japan

BACKGROUND

The incidence of colorectal cancer in adolescent and young adult patients is increasing. However, survival and clinical features of young patients, especially those with stage IV disease, relative to adult patients remain unclear.

METHODS

This retrospective single-institution cohort study was conducted at a tertiary care cancer center. Subjects were 861 consecutive patients who were diagnosed with stage IV colorectal cancer at the age of 15 to 74 years and who were referred to the division of surgery or gastrointestinal oncology at the National Cancer Center Hospital from 1999 to 2013. Overall survival (OS) was investigated and clinicopathological variables were analyzed for prognostic significance.

RESULTS

Of these, 66 (8%) were adolescent and young adult patients and 795 (92%) were adult patients. Median survival time was 13.6 months in adolescent and young adult patients and 22.4 months in adult patients, and 5-year OS rates were 17.3% and 20.3%, respectively, indicating significant worse prognosis of adolescent and young adult patients (p = 0.042). However, age itself was not an independent factor associated with prognosis by multivariate analysis. When compared with adult patients, adolescent and young adult patients consisted of higher proportion of the patients who did not undergo resection of primary tumor, which was an independent factor associated with poor prognosis in multivariate analysis. In patients who did not undergo resection (n = 349), OS of adolescent and young adult patients were significantly worse (p = 0.033).

CONCLUSIONS

Prognoses were worse in adolescent and young adult patients with stage IV colorectal cancer compared to adult patients in Japan, due to a higher proportion of patients who did not undergo resection with more advanced and severe disease, but not due to age itself.

Prognostic Impact of R0 Resection and Targeted Therapy for Colorectal Cancer with Synchronous Peritoneal Metastasis

BACKGROUND

The National Comprehensive Cancer Network guidelines recommend R0 resection and targeted therapy, a combination of cytotoxic and molecular targeted agents, such as bevacizumab, cetuximab, and panitumumab, for colorectal cancer with synchronous peritoneal metastasis (M1c). While these therapeutic strategies are drawing attention, their efficacy has not been fully examined.

METHODS

The study population comprised 248 consecutive M1c patients who were treated at the National Cancer Center Hospital from 1997 to 2013. Multivariate analyses were performed to evaluate relationships between overall survival and R0 resection and targeted therapy using Cox proportional hazards regression models.

RESULTS

The 3-year overall survival (3 yOS) was 19.5%, and median survival time (MST) was 16.2 months in 248 M1c patients. R0 resection was performed in 34 patients (14%), yielding a 3-year overall survival (OS) of 48.3% and median survival time (MST) of 29.9 months. Targeted therapy was performed in 54 patients (22%) at least once during the course of treatment, yielding a 3-yr OS of 38.2% and MST of 23.9 months. After adjusting for other key clinical factors, such as the number of organs involved with metastases, performance status, primary tumor site, and extent of peritoneal metastasis, both R0 resection and targeted therapy were independent factors associated with longer OS. Targeted therapy was associated with a significantly longer OS compared with multiple cytotoxic agent therapy [hazard ratio 0.65; 95% confidence interval (0.44-0.94); p = 0.02].

CONCLUSIONS

If achievable, R0 resection is a desirable therapeutic strategy for patients with M1c colorectal cancer. Moreover, targeted therapy might be the optimal chemotherapy in this patient population.