[The perioperative safety of cytoreductive surgery plus hyperthermic intraperitoneal chemotherapy for pseudomyxoma peritonei].

Objective: This study was to investigate the perioperative safety of cytoreductive surgery (CRS) plus hyperthermic intraperitoneal chemotherapy (HIPEC) for pseudomyxoma peritonei (PMP), and analyze the risk factors of serious adverse events (SAEs). Methods: The occurrences of perioperative SAEs were retrospectively analyzed in 254 PMP patients treated with CRS plus HIPEC. Univariate and multivariate analysis were performed to identify independent risk factors. Results: Among the 272 CRS plus HIPEC procedures for 254 PMP patients, a total of 93 (34.2%) perioperative SAEs occurred, including 26 in infection, 22 in digestive system, 17 in respiratory system, 15 in cardiovascular system, 8 in hematological system, and 4 in urinary system. In terms of severity, the vast majority was grade Ⅲ with 76 cases, followed by grade Ⅳ with 13 cases and grade Ⅴ with 4 cases. Univariate analysis revealed 3 risk factors of perioperative SAEs: HIPEC regimen (P=0.020), intraoperative red blood cell transfusion volume (P=0.004), and intraoperative blood loss volume (P=0.002). Multivariate analysis by logistic regression model analysis revealed that intraoperative red blood cell transfusion volume was an independent risk factor for perioperative SAEs (OR=1.160, P=0.001). Conclusion: In conclusion, the perioperative safety of CRS plus HIPEC was acceptable. Moreover, intraoperative blood loss volume and red blood cell transfusion volume are expected to be reduced in order to prevent SAEs for PMP patients.

[Clinical evaluation of tumor-stroma ratio in pseudomyxoma peritonei from the appendix].

OBJECTIVE: To evaluate the effect of tumor-stroma ratio (TSR) on disease progression and prognosis of pseudomyxoma peritonei (PMP) from the appendix. METHODS: The study included 30 PMP patients with complete individual patient data, who underwent cytoreductive surgery (CRS) plus hyperthermic intraperitoneal chemotherapy (HIPEC) in Beijing Shijitan Hospital. Image-Pro Plus was used to quantitatively analyze the proportion of tumor and stromal areas in hematoxylin-eosin staining pathological images, from which TSR was derived. Correlation studies were conducted to evaluate the relationships between TSR and clinicopathological features, immunohistochemical characteristics, and prognosis of PMP. RESULTS: Among 30 PMP patients, there were 16 males (53.3%) and 14 females (46.7%), with the mean age of (54.9±2.3) years. There were 15 cases (50.0%) of low-grade mucinous carcinoma peritonei (LMCP) and high-grade mucinous carcinoma peritonei (HMCP), respectively, with vascular tumor emboli occurring in 4 cases (13.3%), nerve invasion occurring in 3 cases (10.0%), and lymphatic metastasis occurring in 4 cases (13.3%). The median peritoneal cancer index (PCI) score was 36 (range: 3-39). The median TSR was 8% (range: 2%-24%), with TSR≤10% in 19 cases (63.3%) and TSR>10% in 11 cases (36.7%). Immunohistochemistry showed that 16 cases (53.3%) had Ki67 label index ≤ 50% and 14 cases (46.7%) > 50%. The mutation rate of p53 was 56.7% and the loss rate of MMR protein was 11.8%. In addition, the expression rates of MUC2, MUC5AC, CDX2, CK7, and CK20 were 66.7%, 100.0%, 82.6%, 56.0%, and 92.3%, respectively. There were significant correlations between TSR and histopathological types, nerve invasion, Ki67 label index, and p53 mutation (P<0.05 for all). At the end of the last follow-up, 21 patients (70.0%) died and 9 patients (30.0%) survived, including 6 patients survived with tumor. The median overall survival (OS) was 12.7 months (95%CI: 10.4-11.5 months), and the 1-, 2-, and 3-year survival rates were 60.5%, 32.3%, and 27.7%, respectively. The median OS was 19.4 months (95%CI: 3.0-35.9 months) in the TSR≤10% group, versus 12.6 months (95%CI: 0.7-24.5 months) in the TSR>10% group (χ2=3.996, P=0.046). CONCLUSION: TSR is correlated with histopathological types, tumor proliferation, invasion behaviors and prognosis of PMP, thus could be a new prognostic indicator for PMP.

[Establishment of patient derived xenograft model of high-grade mucinous carcinoma peritonei accompanied with signet ring cells and identification of biological characteristics].

Objective: To establish the patient derived xenograft (PDX) model of pseudomyxoma peritonei (PMP), and identify the key characteristics of tumor biology of this model, in order to provide a reliable model for studying the pathological mechanisms and new therapeutic strategies of PMP. Methods: PMP tumor tissue was obtained from surgery and cut into pieces after washing. Then tumor pieces were implanted subcutaneously in BAL B/c-nu mice for 6 stable passages. In the 7th passage, tumor tissue was implanted orthotopically into abdomen. Subcutaneous tumor and orthotopic tumor were then homogenized to make tumor cell suspension, implanted into abdomen of 10 BAL B/c-nu mice through midline laparotomy, 100 µl for each. The key experimental parameters including body weight changes in the observation period, experimental peritoneal cancer index (ePCI) score at the autopsy, histopathological and immunohistochemical characteristics, and gene expression profiles by high-throughput whole-genome exon sequencing were detected and recorded. Results: The successful rate of established orthotopic PDX model of human PMP was 100% (10/10). The animals showed smooth body weight increases after tumor inoculation until day 27, then the body weight began to decrease steadily. Widespread tumor dissemination of PMP tumor through the whole abdomen was found by autopsy, including the diaphragm, liver, spleen, stomach, kidney, parietal peritoneum, bowel and mesenterium. Gelatinous ascites was also observed in abdominopelvic cavity. The ePCI score ranged from 5 to 9, with a 8 of median ePCI. Histopathological studies showed peritoneal mucinous carcinomatosis accompanied with signet ring cells (PMCA-S), obvious tumor cell atypia and parenchymal invasion.Immunohistochemistry showed the expressions of MUC1, MUC2, MUC5AC, CEA, CA199, CK20, CDX-2 and Ki-67 were positive, MUC6, CK7 and p53 were negative. Whole-exome sequencing identified that the most significant genetic alteration is the exon10 missense mutation c. 1621A>C of KIT gene, the mutation abundance was 89.7%. Conclusion: PDX model of PMCA-S is successfully established, which displays the characters of high-degree malignancy, high proliferation and strong aggressiveness.

[Pathological prognostic factors of pseudomyxoma peritonei].

Objective: To analyze the pathological features of pseudomyxoma peritonei (PMP) in correlation with the survival status and independent prognostic factors. Methods: One-hundred and fifty-five PMP specimens were collected at Beijing Shijitan Hospital, Capital Medical University, from 2012 to 2018. Conventional histopathological evaluation was performed to document the primary tumor site, histopathological type, lymph nodes metastasis, tumor emboli in the blood and lymph vessels, nerve invasion and cellular density. The immunohistochemical parameters including Ki-67, p53, MMR-related protein, MUC2 and MUC5AC were analyzed. Clinical follow-up data were reviewed to correlate with pathological prognostic factors using Kaplan-Meier estimator and Cox proportional hazards regression model for univariate and multivariate analysis. Results: Among 155 PMP patients, there were 77 males and 78 females. There were 98 cases (63.2%) of low-grade peritoneal mucinous carcinomatosis, 49 cases (31.6%) of high-grade peritoneal mucinous carcinomatosis, 8 cases (5.2%) of high-grade mucinous carcinoma peritonei with signet ring cells; only 15 cases (9.7%) with lymph node metastasis; 18 cases (11.6%) with tumor emboli in the blood and lymph vessels; 8/126 (6.3%) were positive dMMR; 100 cases (64.5%) had Ki-67 label index <50%, and 56 cases(36.1%) presented with mutant type p53. Univariate analysis revealed 11 survival-related pathological parameters including gender, age, primary tumor site, histopathological type, lymph node metastasis, tumor emboli in the blood and lymph vessels, nerve invasion, cellular density, Ki-67 label index rate, p53 and dMMR. Multivariate analysis identified 4 independent prognostic factors including the histopathological type (HR 59.78, P<0.01), lymph node metastasis (HR 3.74, P=0.028), nerve invasion (HR 7.81, P=0.007) and dMMR (HR 9.82, P<0.01). Conclusions: Histopathological type is the most important prognostic factor of PMP with dMMR as an independent molecular prognostic indicator.

Cytogenetic studies of five primary esophageal cancers.

In direct preparation of five primary esophageal cancers, chromosomes 1, 3, and 12 were most frequently involved in structural abnormalities; 12p- was consistently seen in all five cases and, thus, could be considered as one of the characteristic chromosome changes in esophageal cancer. Moreover, 2p-, 4p-, and 7q- were seen in three cases.

[Extent of lymph node dissection in rectal carcinoma].

Basing on 170 specimens of advanced rectal cancers radically resected, metastatic rule and extent of lymph node dissection were studied in order to guide future surgical treatment. In 170 cases, 77 had lymph node metastases. The lymph node metastatic rate was 45.3% and metastatic degree was 8.9% (527/5 912). Metastasis of the rectal cancer, according to the lymphatic anatomy, can be divided into upward, lateral and downward drain. Because the rectal cancer at any site can lead to the upward metastasis, the upward lymph node dissection, up to the base of inferior mesenteric artery (the third line of lymph nodes), must be done in all rectal cases, otherwise, 10% of patients would have residual cancer. In view of the lateral metastasis occurring only in rectal cancers under the peritoneal reflection, for which lateral lymph node dissection is necessary or one eighth of patients would have residual lesion. Generally, no lateral lymph node dissection is needed in cancers above the peritoneal reflection. Pathologic factor influencing the lymphatic metastasis is the form of tumor growth, such as poorly differentiated and mucoid adenocarcinomas aggressively growing deeply and extensively resulting in a higher lymph node metastatic rate, for which lymph node dissection must be performed.

[Clinicopathological study of combined preoperative radiotherapy with intracavitary hyperthermia in rectal cancer].

118 specimens of rectal cancer were studied pathologically. 40 cases were treated by both preoperative radiotherapy and intracavitary hyperthermia (group 1), 38 treated by preoperative radiotherapy alone (group 2) and 40 by operation alone (group 3). The tumor disappearance rates by gross observation were 57.5% and 5.3% in groups 1 and 2 (P less than 0.001). The moderate to severe damage of cancer cells (X2-X4) was observed in 90% of cases in group 1 and 31.6% in group 2 (P less than 0.05). In the former, the cancer cell disappearance was observed in 8 cases, while in the latter, only 1 case. The cell degenerations by 30 Gy plus hyperthermia were similar to those by 40 Gy plus hyperthermia, but both were more marked than by 30 Gy alone or 40 Gy alone (P less than 0.05). The lymphocyte, plasma cell infiltration and hyperplasia of fibrous tissue around the tumor in group 1 were more marked than those in groups 2 and 3 (P less than 0.05). The thrombosis around the tumor was more in group 1 than in group 2 (P less than 0.01). Every histological type of the tumor was sensitive to radiotherapy combined with hyperthermia. The lymph node metastatic rates were 35% in group 1 and 31.6% in group 2, both being lower than that in group 3 (52.5%). Immune function of the lymph nodes and the damage of the normal tissues around the tumor are observed. It has been clinically confirmed that neither resection rate is influenced nor postoperative complications are increased by preoperative radiotherapy combined with hyperthermia.

Combination preoperative radiation and endocavitary hyperthermia for rectal cancer: long-term results of 44 patients.

Long-term results of 122 patients with advanced rectal cancer who were randomly treated with three different methods from July 1984 to July 1986. Of 122 patients, 44 were treated with endocavitary 915 MHz microwave applicators combined with 10 MeV X-ray or 60CO followed by surgery (group A), 38 with preoperative radiation (group B) and 40 with surgery (group C) as a control group. The temperature on the surface of the applicator touching the middle of the caudad to cephaladic extent of disease was 45-50 degrees C for 45 min twice a week for 6-8 sessions. Radiation dose was 30 Gy or 40 Gy/4 weeks. Of cases with stages 0 and A, 45.5% (20/44) were in group A, 23.7% (9/38) in group B and 12.5% (5/40) in group C (chi 2 test p < 0.05 and p < 0.01, respectively). Five-year survival rate was 66.7% (24/36) in group A, 50% (14/28) in group B and 40.5% (15/37) in group C. Percentage of survival at 5 years was 73.7% (14/19) for 40 Gy plus heat, 57.1% (8/14) for 40 Gy alone, 58.8% (10/17) for 30 Gy plus heat, and 42.9% (6/14) for 30 Gy alone. Data suggest a survival advantage for patients treated with preoperative radiation combined with endocavitary hyperthermia.