Colorectal cancer (CRC) is one of the most common malignant tumors in China, ranking second in morbidity and fourth in mortality. Metastasis and recurrence are the leading causes of patient death, and the peritoneum is a frequent site of metastasis in CRC, second only to liver and lung metastases. However, the prognosis of peritoneal metastasis is much worse than hepatic and pulmonary metastasis. CRC peritoneal metastasis is challenging early diagnosis, presents with severe symptoms, and has a poor prognosis. It is crucial to emphasize standardized diagnosis and treatment for CRC peritoneal metastasis to improve patients' outcome and enhance their quality of life. This consensus, based on evidence-based medical evidence, revised the "Chinese Expert Consensus on the Diagnosis and Treatment of Colorectal Cancer Peritoneal Metastasis (2022 edition)" and reached a preliminary consensus on the definition, diagnosis, treatment, and prevention of CRC peritoneal metastasis, with the aim of guiding and standardizing the diagnosis and treatment of CRC peritoneal metastasis, developing reasonable and effective comprehensive treatment plans, prolonging survival time and improving quality of life for CRC peritoneal metastasis patients, thereby raising the overall level of diagnosis and treatment for CRC in China.
Humans ; Peritoneal Neoplasms/therapy* ; Colorectal Neoplasms/diagnosis* ; Consensus ; Quality of Life ; Prognosis ; China

Epithelial tumors of the appendix refer to neoplastic lesions originating from the epithelial tissue of the appendix mucosa. These neoplasms exhibit highly heterogeneous pathological features and biological behavior, which contribute to their strong propensity for peritoneal metastasis. Currently, evidence-based medicine regarding appendiceal epithelial neoplasms and the management of their peritoneal metastasis is limited, leading to a lack of standardized clinical practices. To address this, the Professional Committee of Integrated Rehabilitation for Peritoneal Tumors of the Chinese Anti-Cancer Association has organized multidisciplinary experts to focus on key aspects such as the pathological classification of epithelial tumors of the appendix, clinical staging of tumors,the indications for extended resection after local resection, the surgical treatment strategies for concurrent peritoneal metastasis, perioperative rehabilitation, and individualized treatment, while integrating the technical capabilities of relevant specialties. At the same time, it has standardized the perioperative management of cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC), as well as the clinical application of the pre-rehabilitation system, to enhance the practical operability. Ultimately, the Expert Consensus on the Comprehensive Management of Peritoneal Metastasis from Appendiceal Epithelial Neoplasms (2025 Edition) was developed. This consensus is aimed at further standardizing the systematic diagnosis and treatment process of epithelial tumors of the appendix, thereby reducing the risk of recurrence, improving patient prognosis, and promoting the standardization and homogenization of the diagnosis and treatment of peritoneal metastasis from such tumors.
Humans ; Appendiceal Neoplasms/therapy* ; Peritoneal Neoplasms/therapy* ; Cytoreduction Surgical Procedures ; Consensus ; Hyperthermic Intraperitoneal Chemotherapy

Background: Follicular dendritic cell sarcoma (FDCS) accounts for about 0.4% of soft tissue sarcomas. Approximately onethird of cases occur in extranodal sites and about 28% of extranodal FDCS may metastasize. Intra-abdominal occurrence is rare and there is limited published data to guide oncologists on how to best treat this malignancy. Case Presentation: This is a case of a 33-year-old female who came in due to incidental finding of a left supraclavicular mass with 2-year history of early satiety. Neck node biopsy revealed a poorly differentiated malignant tumor with positive staining for CD21, CD23, vimentin and S100 consistent with FDCS. PET-CT revealed an intensely FDG-avid large mass in the left upper abdomen with signs of necrosis and mass effect. The patient was given three different chemotherapy regimens that included (1) gemcitabine/docetaxel, (2) single agent doxorubicin and (3) ifosfamide/etoposide, but she progressed on all these. Off-label use of bendamustine was then offered and after just the first cycle, the patient reportedly regained strength and was able to get up from wheelchair with noted interval decrease in size of the cervical mass. Unfortunately, the patient deteriorated and succumbed to infection and multiple pulmonary embolisms. Conclusion Intra-abdominal FDCS is a rare malignancy with heterogenous outcomes with no uniform treatment strategy at present. Molecular tumor board discussion and multi-disciplinary approach in extranodal FDCS is important in the diagnosis and management. Patients with multiple poor prognostic factors are at risk for tumor recurrence, metastasis, and death.
Dendritic Cell Sarcoma, Follicular ; Abdominal Neoplasms ; Drug Therapy ; Bendamustine Hydrochloride ; Prognosis

China is a country with a high incidence of gastric cancer, and the majority of patients are in the advanced stage. The peritoneum is the most common site of metastasis and recurrence in advanced gastric cancer. Attention to the standardized diagnosis and treatment of peritoneal metastases of gastric cancer is expected to significantly improve the prognosis and quality of life of some patients. Based on evidence-based medicine and the internationally accepted Delphi method, this consensus revises the Chinese expert consensus on the prevention and treatment of peritoneal metastasis of gastric cancer (2017 edition), reaches a preliminary consensus on the definition, classification, risk factors, diagnosis and prediction, grade assessment, prevention, treatment and management of complications of peritoneal metastasis of gastric cancer, and provides guidance for clinical work.
Humans ; Peritoneum/pathology* ; Peritoneal Neoplasms/therapy* ; Stomach Neoplasms/pathology* ; Consensus ; East Asian People ; Quality of Life ; China

Modern clinical oncology has made great achievements over the last century. However, peritoneal metastasis from gastrointestinal cancer, as one of three most common metastasis modalities, was not re-recognized until the end of the last century, and a normative diagnosis and treatment system has been gradually beginning to be formed until today. This comment is to review the development history, reflect on the lessons and experiences in clinical practice, analyze the difficulties on redefinition, deep understanding and clinical management, and pain points on theory construction, technique practice and discipline construction, in the field of gastrointestinal cancer peritoneal metastasis. We suggested a solution to the difficulties and pain points by realizing the fact of burden of peritoneal metastasis, reinforcing technical training, and promoting collaborative researches, aiming to provide reference for the steady development of peritoneal surface oncology.
Humans ; Peritoneal Neoplasms/secondary* ; Gastrointestinal Neoplasms ; China ; Pain

Peritoneal metastasis is one of the most frequent patterns of metastasis in gastric cancer, and remains a major unmet clinical problem. Thus, systemic chemotherapy remains the mainstay of treatment for gastric cancer with peritoneal metastasis. In well-selected patients, the reasonable combination of cytoreductive surgery, hyperthermic intraperitoneal chemotherapy (HIPEC), and neoadjuvant intraperitoneal chemotherapy with systemic chemotherapy will bring significant survival benefits to patients with gastric cancer peritoneal metastasis. In patients with high-risk factors, prophylactic therapy may reduce the risk of peritoneal recurrence, and improves survival after radical gastrectomy. However, high-quality randomized controlled trials will be needed to determine which modality is better. The safety and efficacy of intraoperative extensive intraperitoneal lavage as a preventive measure has not been proven. The safety of HIPEC also requires further evaluation. HIPEC and neoadjuvant intraperitoneal and systemic chemotherapy have achieved good results in conversion therapy, and it is necessary to find more efficient and low-toxicity therapeutic modalities and screen out the potential benefit population. The efficacy of CRS combined with HIPEC on peritoneal metastasis in gastric cancer has been preliminarily validated, and with the completion of clinical studies such as PERISCOPE II, more evidence will be available.
Humans ; Stomach Neoplasms/pathology* ; Peritoneal Neoplasms/secondary* ; Antineoplastic Combined Chemotherapy Protocols/therapeutic use* ; Hyperthermia, Induced/methods* ; Peritoneum/pathology* ; Combined Modality Therapy ; Cytoreduction Surgical Procedures/methods* ; Survival Rate

Peritoneal metastasis of gastric cancer serving as the most frequent form of metastasis, is one of the leading causes of death. A portion of surgically treated patients often suffer from small peritoneal residual metastasis, which will lead to recurrence and metastasis of gastric cancer patients after surgery. Given these, the prevention and treatment of peritoneal metastasis of gastric cancer deserves more attention. Molecular residual disease (MRD) refers to the molecular abnormalities of tumor origin that cannot be found by traditional imaging or other laboratory methods after treatment, but can be found by liquid biopsy, representing the possibility of tumor persistence or clinical progress. In recent years, the detection of MRD based on ctDNA has gradually become a research hotspot in the prevention and treatment of peritoneal metastasis. Our team established a new method for MRD molecular diagnosis of gastric cancer, and reviewed the research achievements in this field.
Humans ; Stomach Neoplasms/pathology* ; Peritoneal Neoplasms/secondary* ; Liquid Biopsy ; Neoplasm, Residual/genetics*

Peritoneal metastatic colorectal cancer (pmCRC) is common and has been considered as the terminal stage. The theory of "seed and soil" and "oligometastasis" are the acknowledged hypotheses of pathogenesis of pmCRC. In recent years, the molecular mechanism related to pmCRC has been deeply researched. We realize that the formation of peritoneal metastasis, from detachment of cells from primary tumor to mesothelial adhesion and invasion, depends on the interplay of multiple molecules. Various components of tumor microenvironment also work as regulators in this process. Cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) have been widely used in clinical practice as an established treatment for pmCRC. Besides systemic chemotherapy, targeted and immunotherapeutic drugs are also increasingly used to improve prognosis. This article reviews the molecular mechanisms and treatment strategies related to pmCRC.
Humans ; Colorectal Neoplasms/pathology* ; Combined Modality Therapy ; Peritoneal Neoplasms/secondary* ; Hyperthermia, Induced ; Colonic Neoplasms/therapy* ; Rectal Neoplasms/therapy* ; Antineoplastic Combined Chemotherapy Protocols/therapeutic use* ; Prognosis ; Cytoreduction Surgical Procedures ; Survival Rate ; Tumor Microenvironment

The prognosis of patients with peritoneal metastasis from colorectal cancer is poor. At present, the comprehensive treatment system based on cytoreductive surgery (CRS) combined with hyperthermic intraperitoneal chemotherapy (HIPEC) has significantly improved the survival of these patients. However, CRS and HIPEC have strict indications, high procedural difficulty, and high morbidity and mortality. If CRS+HIPEC is performed in an inexperienced center, overall survival and quality of life of patients may bo compromised. The establishment of specialized diagnosis and treatment centers can provide a guarantee for standardized clinical diagnosis and treatment. In this review, we first introduced the necessity of establishing a colorectal cancer peritoneal metastasis treatment center and the construction situation of the diagnosis and treatment center for peritoneal surface malignancies at home and abroad. Then we focused on introducing our construction experience of the colorectal peritoneal metastasis treatment center, and emphasized that the construction of the center must be done well in two aspects: firstly, the clinical optimization should be realized and the specialization of the whole workflow should be strengthened; secondly, we should ensure the quality of patient care and the rights, well-being and health of every patient.
Humans ; Peritoneal Neoplasms/secondary* ; Combined Modality Therapy ; Quality of Life ; Hyperthermia, Induced ; Chemotherapy, Cancer, Regional Perfusion ; Prognosis ; Antineoplastic Combined Chemotherapy Protocols/therapeutic use* ; Colorectal Neoplasms/pathology* ; Cytoreduction Surgical Procedures ; Survival Rate

Objectives: To construct a nomogram incorporating important prognostic factors for predicting the overall survival of patients with colorectal cancer with peritoneal metastases treated with cytoreductive surgery (CRS) plus hyperthermic intraperitoneal chemotherapy (HIPEC), the aim being to accurately predict such patients' survival rates. Methods: This was a retrospective observational study. Relevant clinical and follow-up data of patients with colorectal cancer with peritoneal metastases treated by CRS + HIPEC in the Department of Peritoneal Cancer Surgery, Beijing Shijitan Hospital, Capital Medical University from 2007 January to 2020 December were collected and subjected to Cox proportional regression analysis. All included patients had been diagnosed with peritoneal metastases from colorectal cancer and had no detectable distant metastases to other sites. Patients who had undergone emergency surgery because of obstruction or bleeding, or had other malignant diseases, or could not tolerate treatment because of severe comorbidities of the heart, lungs, liver or kidneys, or had been lost to follow-up, were excluded. Factors studied included: (1) basic clinicopathological characteristics; (2) details of CRS+HIPEC procedures; (3) overall survival rates; and (4) independent factors that influenced overall survival; the aim being to identify independent prognostic factors and use them to construct and validate a nomogram. The evaluation criteria used in this study were as follows. (1) Karnofsky Performance Scale (KPS) scores were used to quantitatively assess the quality of life of the study patients. The lower the score, the worse the patient's condition. (2) A peritoneal cancer index (PCI) was calculated by dividing the abdominal cavity into 13 regions, the highest score for each region being three points. The lower the score, the greater is the value of treatment. (3) Completeness of cytoreduction score (CC), where CC-0 and CC-1 denote complete eradication of tumor cells and CC-2 and CC-3 incomplete reduction of tumor cells. (4) To validate and evaluate the nomogram model, the internal validation cohort was bootstrapped 1000 times from the original data. The accuracy of prediction of the nomogram was evaluated with the consistency coefficient (C-index), and a C-index of 0.70-0.90 suggest that prediction by the model was accurate. Calibration curves were constructed to assess the conformity of predictions: the closer the predicted risk to the standard curve, the better the conformity. Results: The study cohort comprised 240 patients with peritoneal metastases from colorectal cancer who had undergone CRS+HIPEC. There were 104 women and 136 men of median age 52 years (10-79 years) and with a median preoperative KPS score of 90 points. There were 116 patients (48.3%) with PCI≤20 and 124 (51.7%) with PCI>20. Preoperative tumor markers were abnormal in 175 patients (72.9%) and normal in 38 (15.8%). HIPEC lasted 30 minutes in seven patients (2.9%), 60 minutes in 190 (79.2%), 90 minutes in 37 (15.4%), and 120 minutes in six (2.5%). There were 142 patients (59.2%) with CC scores 0-1 and 98 (40.8%) with CC scores 2-3. The incidence of Grade III to V adverse events was 21.7% (52/240). The median follow-up time is 15.3 (0.4-128.7) months. The median overall survival was 18.7 months, and the 1-, 3- and 5-year overall survival rates were 65.8%, 37.2% and 25.7%, respectively. Multivariate analysis showed that KPS score, preoperative tumor markers, CC score, and duration of HIPEC were independent prognostic factors. In the nomogram constructed with the above four variables, the predicted and actual values in the calibration curves for 1, 2 and 3-year survival rates were in good agreement, the C-index being 0.70 (95% CI: 0.65-0.75). Conclusions: Our nomogram, which was constructed with KPS score, preoperative tumor markers, CC score, and duration of HIPEC, accurately predicts the survival probability of patients with peritoneal metastases from colorectal cancer treated with cytoreductive surgery plus hyperthermic intraperitoneal chemotherapy.
Male ; Humans ; Female ; Middle Aged ; Peritoneal Neoplasms/secondary* ; Nomograms ; Cytoreduction Surgical Procedures/adverse effects* ; Hyperthermic Intraperitoneal Chemotherapy ; Quality of Life ; Hyperthermia, Induced ; Prognosis ; Combined Modality Therapy ; Antineoplastic Combined Chemotherapy Protocols/therapeutic use* ; Colorectal Neoplasms/pathology* ; Retrospective Studies ; Survival Rate