Long-term prognostic value of conventional peritoneal cytology after curative resection for colorectal carcinoma

The Use of CellCollector Assay to Detect Free Cancer Cells in the Peritoneal Cavity of Colorectal Cancer Patients: An Experimental Study

BACKGROUND

Colorectal cancer (CRC) is associated with high incidence and mortality rates globally. The presence of intraperitoneal free cancer cells (IFCCs) is recognized as an independent prognostic factor for CRC patients. However, a clinical gold standard for IFCCs detection is lacking. The GILUPI CellCollector has demonstrated high sensitivity and specificity in detecting free cancer cells, yet its application for CRC IFCCs detection remains unreported.

METHODS

We selected CRC and normal cell lines to evaluate the CellCollector's ability to detect tumor cells. A total of 70 CRC patients and 17 patients with benign disease undergoing laparoscopic procedures were investigated. Peritoneal lavage fluid was collected pre- and post-operation, and both real-time PCR (CEA mRNA) and CellCollector detection were performed. We compared the sensitivity and specificity of these two methods.

RESULTS

CellCollector can distinguish well between CRC and normal cells in cell line experiments. CellCollector detects IFCCs better than real-time PCR (CEA) in CRC patients in different TNM Stages. The sensitivity of CellCollector was higher than that of real-time PCR (84.6% vs. 48.4%), and the specificity of CellCollector was also higher than real-time PCR (79.1% vs. 60.4%). There was no significant difference in the results of IFCCs detected by CellCollector before and after total mesorectal excision (TME) or complete mesocolic excision (CME) radical colorectomy (p > 0.05), but there was a significant difference in real-time PCR detection (p < 0.05).

CONCLUSIONS

The CellCollector demonstrates superior sensitivity and specificity compared to real-time PCR for detecting IFCCs in CRC patients, suggesting its potential as a clinical tool for IFCCs detection.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT01978444.

Peritoneal lavage cytology in patients with curative resection for stage II and III colorectal cancer: A multi-institutional prospective study

Aim

To clarify the usefulness of intraoperative lavage cytology in patients undergoing curative resection for pStage II-III colorectal cancer in a prospective multicenter study.

Methods

Patients preoperatively diagnosed with stage II-III colorectal cancer between 2013 and 2017 from 20 hospitals were enrolled. Lavage cytology was performed twice during the surgery. The primary endpoint was the effect of lavage cytology on the 5-year relapse-free survival (RFS) in patients with pStage II-III colorectal cancer. The secondary endpoint was the effect of lavage cytology on the 5-year overall survival (OS) and peritoneal recurrence.

Results

A total of 1378 patients were eligible for analysis. The number of patients with pStage II-III colorectal cancer was 670 and 708, respectively. Fifty-four patients (3.9%) had positive cytological results. In pStage II patients, the 5-year RFS rates with positive and negative cytology were 61.1% and 81.6%, respectively (p = 0.023). The 5-year OS rates were 67.1% and 91.7%, respectively (p = 0.0083). However, there was no difference in RFS or OS between pStage III patients with positive and negative cytology results. The peritoneal recurrence rates were 11.8% and 1.5% in pStage II patients with positive and negative cytology results, respectively (p = 0.032). These rates were 10.5% and 2.5% in patients with stage III disease, respectively (p = 0.022).

Conclusion

Stage II colorectal cancer patients with negative cytology had better outcomes than those with positive cytology. Peritoneal lavage cytology is useful for predicting peritoneal recurrence after curative resection of stage II-III colorectal cancer.

Long noncoding RNA small nucleolar RNA host gene 1 as a potential novel biomarker for intraperitoneal free cancer cells in colorectal cancer

Colorectal cancer (CRC) is a prevalent cancer with intraperitoneal free cancer cells (IFCCs) playing a significant role in prognosis, especially during surgeries. The identification of IFCCs is crucial for determining the stage and treatment of patients with CRC. Existing methods for IFCC detection, such as conventional cytology, immunocytochemistry (ICC), and polymerase chain reaction (PCR), have limitations in sensitivity and specificity. This study investigates the potential of long noncoding RNA (lncRNA) SNHG1 as a biomarker for detecting IFCCs in patients with CRC. Testing on a cohort of 91 patients with CRC and 26 patients with gastrointestinal benign disease showed that SNHG1 outperformed CEA in distinguishing CRC cells and detecting IFCCs across different disease stages. SNHG1 demonstrated higher sensitivity (76.1% vs. 43.1%) and specificity (68.4% vs. 52.3%) than CEA for IFCC detection in patients with CRC, suggesting its promising role as a clinical method for identifying IFCCs in CRC.

Risk factors for metachronous peritoneal carcinomatosis after radical resection for patients with nonmetastatic pT3-4 colon cancer

BACKGROUND

Patients with nonmetastatic pT3-4 colon cancers are prone to develop metachronous peritoneal carcinomatosis (mPC). Risk factors for mPC and the influence of mutant kirsten rat sarcoma viral oncogene (KRAS)/neuroblastoma rat sarcoma (NRAS)/v-raf murine sarcoma viral oncogene homolog B1 (BRAF) and DNA mismatch repair (MMR) status on mPC remain to be described in these patients.

METHOD

All enrolled patients were identified from the prospectively collected colorectal cancer database of a tertiary referral hospital between 2013 and 2018. Multivariate analysis was used to identify risk factors associated with mPC.

RESULTS

Of the 1689 patients with nonmetastatic pT3-4 colon carcinoma, 8.4% (142/1689) progressed to mPC. Endoscopic obstruction (HR = 3.044, p < 0.001), elevated CA125 (HR = 1.795, p = 0.009), pT (T4a vs. T3, HR = 2.745, p < 0.001; T4b vs. T3, HR = 3.167, p = 0.001), pN (N1 vs. N0, HR = 2.592, p < 0.001; N2 vs. N0, HR = 4.049, p < 0.001), less than 12 lymph nodes harvested (HR = 2.588, p < 0.001), mucinous or signet ring cell carcinoma (HR = 1.648, p = 0.038), perineural invasion (HR = 1.984, p < 0.001), and adjuvant chemotherapy (HR = 1.522, p = 0.039) were strongly related to mPC but that mutant KRAS/NRAS/BRAF and MMR status was not associated with mPC.

CONCLUSION

This study identified the high-risk factors for mPC in patients with nonmetastatic pT3-4 colon carcinoma, and these factors should be considered in selective preventive therapy and close follow-up for patients subsequently deemed to have high risk for mPC.

Factors Affecting Positive Peritoneal Lavage Cytology in Patients with Stage II and III Colorectal Cancer with R0 Resection: A Multi-institutional, Prospective Study

Objectives:

This study aimed to explore the risk factors associated with cancer cell exfoliation in Stage II and III colorectal cancer (CRC).

Methods:

This multicenter, prospective, observational study targeted 1,698 patients with cStage II and III CRC who underwent R0 resection between 2013 and 2017. Clinicopathological variables were analyzed for correlations with positive peritoneal lavage cytology (PLC).

Results:

The positive PLC rate was 2.7% (46/1,694 cases) at laparotomy and 1.6% (25/1,590 cases) after tumor resection. Logistic regression analyses identified that undifferentiated histologies diagnosed by preoperative biopsy specimen, cT4, and pN+ were independent factors that affected the positive PLC at laparotomy. The positive PLC rate at laparotomy was 4.5% (33/736 cases) among the patients with undifferentiated histology and/or cT4. Logistic regression analyses revealed that the presence of ascites and undifferentiated histology by biopsy independently affected positive PLC after tumor resection.

Conclusions:

The undifferentiated histology and/or T4 indicated by preoperative diagnosis were identified as factors affecting PLC at laparotomy. Furthermore, ascites and preoperative histological type were identified as factors affecting positive PLC after tumor resection. As factors affecting positive PLC, these preoperative findings were found to be equivalent to pathological findings.

Risk factors for developing peritoneal metastases after curative surgery for colorectal cancer: A systematic review and meta-analysis

AIM

Proactive detection and treatment strategies have achieved encouraging survival outcomes for patients with early peritoneal metastases (PM), but these costly and invasive approaches can only be applied to selected high-risk patients. This meta-analysis aimed to identify the risk factors for metachronous PM after curative surgery for colorectal cancer (CRC).

METHOD

The study was registered at PROSPERO (CRD42020219187). Databases were searched for studies comparing clinical and histopathological characteristics between patients with metachronous peritoneal metastases from colorectal cancer (pmCRC) and patients without (non-pmCRC).

RESULTS

Thirty-six studies were included. Metachronous PM were positively associated with perforation (OR 1.920; 95% CI 1.144-3.223; P = 0.014), poor differentiation (OR 2.291; 1.603-3.275; P < 0.001), T4 (OR 2.897; 1.248-6.726; P = 0.013), N1-2 (OR 3.429; 2.684-4.381; P < 0.001), mucinous adenocarcinoma (OR 4.175; 1.798-9.692; P = 0.001), obstruction (OR 4.467; 1.919-10.398; P = 0.001), synchronous ovarian metastases (OR 5.005; 1.140-21.977; P = 0.033), positive peritoneal carcinoembryonic antigen mRNA (OR 9.472; 3.643-24.631; P < 0.001), elevated serum carcinoembryonic antigen (preoperative group, OR 3.545, 1.486-8.459, P = 0.004; postoperative group, OR 13.673, 2.222-84.129, P = 0.005), elevated serum cancer antigen 19-9 (preoperative group, OR 5.281, 2.146-12.994, P < 0.001; postoperative group, OR 18.646, 6.429-54.083, P < 0.001) and positive peritoneal cytology (OR 25.884; 11.372-58.913; P < 0.001).

CONCLUSION

These evidence-based risk factors are conducive to designing early detection and proactive treatment strategies, enabling precision medicine.

CXCL2-CXCR2 axis mediates αV integrin-dependent peritoneal metastasis of colon cancer cells

Peritoneal metastasis is an insidious aspect of colorectal cancer. The aim of the present study was to define mechanisms regulating colon cancer cell adhesion and spread to peritoneal wounds after abdominal surgery. Mice was laparotomized and injected intraperitoneally with CT-26 colon carcinoma cells and metastatic noduli in the peritoneal cavity was quantified after treatment with a CXCR2 antagonist or integrin-αV-antibody. CT-26 cells expressed cell surface chemokine receptors CXCR2, CXCR3, CXCR4 and CXCR5. Stimulation with the CXCR2 ligand, CXCL2, dose-dependently increased proliferation and migration of CT-26 cells in vitro. The CXCR2 antagonist, SB225002, dose-dependently decreased CXCL2-induced proliferation and migration of colon cancer cells in vitro. Intraperitoneal administration of CT-26 colon cancer cells resulted in wide-spread growth of metastatic nodules at the peritoneal surface of laparotomized animals. Laparotomy increased gene expression of CXCL2 at the incisional line. Pretreatment with CXCR2 antagonist reduced metastatic nodules by 70%. Moreover, stimulation with CXCL2 increased CT-26 cell adhesion to extracellular matrix (ECM) proteins in a CXCR2-dependent manner. CT-26 cells expressed the αV, β1 and β3 integrin subunits and immunoneutralization of αV abolished CXCL2-triggered adhesion of CT-26 to vitronectin, fibronectin and fibrinogen. Finally, inhibition of the αV integrin significantly attenuated the number of carcinomatosis nodules by 69% in laparotomized mice. These results were validated by use of the human colon cancer cell line HT-29 in vitro. Our data show that colon cancer cell adhesion and growth on peritoneal wound sites is mediated by a CXCL2-CXCR2 signaling axis and αV integrin-dependent adhesion to ECM proteins.

Comparison of prognostic impact between positive intraoperative peritoneal and lavage cytologies in colorectal cancer

BACKGROUND

The prognostic value of positive intraoperative peritoneal cytology and lavage cytology, including the differences in their prognostic impact, in colorectal cancer is controversial. We aimed to investigate the prognostic values of positive peritoneal cytology and lavage cytology findings for colorectal cancer and compare their prognostic impact.

METHODS

We retrospectively evaluated 592 clinical stage II-IV colorectal cancer patients who underwent peritoneal cytology (n = 225) or lavage cytology (n = 367) between November 1993 and December 2018. The prognostic factors for cancer-specific survival were identified, and the differences in cancer-specific survival were examined between the patients.

RESULTS

The cytology-positive rate was 10.8% (64/592), 17.8% (40/225), and 6.5% (24/367) in the overall, peritoneal cytology, and lavage cytology groups, respectively. Both positive peritoneal cytology (hazard ratio: 2.196) and lavage cytology (hazard ratio: 2.319) were independent prognostic factors. The peritoneal cytology-positive group showed significantly poorer cancer-specific survival than the cytology-negative group (5-year: 3.5% vs. 59.5%; 10-year: 3.5% vs. 46.1%, p < 0.001). Similar results were obtained for lavage cytology (5-year: 14.1% vs. 73.9%; 10-year: 4.7% vs. 63.5%, p < 0.001). The cancer-specific survival was not significantly different between the peritoneal cytology-positive and lavage cytology-positive groups (p = 0.058). Both positive peritoneal and lavage cytology were associated with poorer cancer-specific survival across all colorectal cancer stages.

CONCLUSIONS

Positive peritoneal and lavage cytology are associated with worse cancer-specific survival in colorectal cancer. The prognostic impact was comparable between positive lavage and peritoneal cytology. Thus, cytology should be a standard assessment modality for colorectal cancer.

Is ascites CEA a risk factor for peritoneal carcinomatosis in colorectal cancer?: a long-term follow-up study

PURPOSE

Our previous study reported that carcinoembryonic antigen (CEA) levels in peritoneal fluid were significantly correlated with the prevalence of peritoneal carcinomatosis (PC) in colorectal cancer (CRC). The purpose of this study was a long-term follow up of the author's previous study, as well as the identification of correlations with the known risk factors of PC and the comparison of the predictive power of PC in CRC.

METHODS

A total of 495 patients without PC who underwent CRC operations at St. Mary's Hospital, The Catholic University of Korea, from January 2006 to November 2014 were included in this study. Tumor markers of peritoneal fluid sampled at the beginning of each operation were prospectively analyzed and compared with the known risk factors for PC in CRC.

RESULTS

Multivariate analysis of PC revealed that T4 cancer (OR 5.143, 95% CI 1.400-18.897, p = 0.014), T3 mucinous cancer (OR 17.480, 95% CI 1.577-193.714, p = 0.020), obstructed tumors (OR 6.030, 95% CI 1.627-22.343, p = 0.007), and peritoneal fluid CEA above 5 ng/dl (OR 4.073, 95% CI 1.315-12.615, p = 0.015) were significant risk factors. T4 cancer, obstructed tumors, and peritoneal fluid CEA above 5 ng/dl showed correlations with cancer-free survival. Generally, higher CEA levels in peritoneal fluid were correlated with previously known risk factors for PC in CRC.

CONCLUSION

Peritoneal fluid CEA has predictive value for PC and prognostic value in CRC. Therefore, we recommend routinely performing ascites CEA analysis in colorectal cancer surgery.

Neutrophil extracellular traps promote peritoneal metastasis of colon cancer cells

Cytoreductive surgery is the only curative option for patients with peritoneal carcinomatosis, however, intraperitoneal recurrence rate is high making new ways to prevent cancer recurrence an urgent need. Recent evidence suggests that neutrophils are involved in cancer progression. The purpose of our study was to examine the role of neutrophils in the spread of colon cancer cells in the peritoneal cavity.

The number of metastatic noduli in the peritoneal cavity was quantified in mice injected with murine colon cancer cells (CT-26) intraperitoneally after surgical laparotomy and treated with a neutrophil depleting antibody or DNase I. In addition, peritoneal metastases were harvested from patients with peritoneal carcinomatosis. Scanning and transmission electron microscopy showed extensive neutrophil extracellular trap (NET) formation in peritoneal colon cancer metastases in mice and patients. Neutrophil depletion markedly reduced the number of metastases in laparotomised animals. Administration of DNase I decreased the number of metastatic nodules by 88% in laparotomised animals as well as NET-induced chemokine-dependent colon cancer cell migration and adhesion in vitro. Finally, CT-26 cancer cells were found to express the α_vβ₃ integrin and inhibition of αv integrin abolished NET-induced adhesion of colon cancer cells to vitronectin. Taken together, our data show that NETs play an important role in colon cancer cell metastasis in the peritoneal cavity and regulate colon cancer cell migration and adhesion to extracellular matrix proteins. These novel findings suggest that targeting NETs might be an effective strategy to antagonize intrabdominal recurrences of colon cancer after cytoreductive surgery in patients with peritoneal carcinomatosis.

Diagnostic Value of Carcinoembryonic Antigen in Ascites for Colorectal Cancer with Peritoneal Carcinomatosis

Background/Aims

Diagnostic tests for carcinoembryonic antigen (CEA) in ascites have been performed in various malignant cases, but there is only few data on the applicability of CEA for colorectal cancer (CRC) patients with peritoneal carcinomatosis. We aimed to determine the usefulness of CEA in ascites (aCEA) as a diagnostic parameter for CRC with peritoneal carcinomatosis.

Methods

Between January 2000 and May 2013, the medical records of 259 patients who underwent paracentesis for the evaluation of ascites were retrospectively reviewed. CRC patients with ascites (n=82) and patients with non-malignant ascites (n=177) were evaluated. Patients who had other malignancies, including gastric or ovarian cancer, with ascites were excluded. The optimal diagnostic cut-off value of aCEA for CRC with peritoneal carcinomatosis was determined using receiver operating characteristic curve analysis. The value of aCEA for predicting the occurrence of peritoneal carcinomatosis was evaluated using a logistic regression model.

Results

The optimal cut-off value of aCEA to diagnose CRC with peritoneal carcinomatosis was 3.89 ng/mL, and the area under the curve for aCEA was 0.996 (sensitivity 96.3%, specificity 100%, positive predictive value 100%, negative predictive value 98.3%). Multivariate logistic regression analysis showed that aCEA was an independent factor predicting the occurrence of peritoneal carcinomatosis.

Conclusions

In this study, we showed that aCEA may be a useful parameter for diagnosing CRC with peritoneal carcinomatosis, and we propose an optimal aCEA cut-off value of 3.89 ng/mL. Further study that includes patients with other malignant ascites may be necessary to validate these findings.

Applications of hyperthermic intraperitoneal chemotherapy for metastatic colorectal cancer

INTRODUCTION

Cytoreductive surgery (CRS) combined with hyperthermic intraperitoneal chemotherapy (HIPEC) plays a pivotal role in the current treatment of peritoneal carcinomatosis (PC) from colorectal cancer (CRC). Since the first demonstration, benefits for patients and especially an increase in survival have been described. In recent years, feasibility, efficacy and safety of HIPEC have been improved and progress has been made in understanding its oncological mechanism. Areas covered: In this article, leading publications have been reviewed including clinical trials to describe the clinical presentation of PC due to CRC and present recent evidence of the CRS/HIPEC procedure. The surgical approach including evaluation of the extent of PC is described and, in addition, the article reports about different HIPEC techniques as well as several protocols. Furthermore, the development and prognostic benefit of the combination of intraperitoneal and intravenous chemotherapy are outlined. Consideration has been given in particular to patient selection and the use of HIPEC if complete cytoreduction is not feasible. Expert commentary: The CRS/HIPEC procedure represents a curative approach to treat patients with PC from CRC. However, surgical skills and the HIPEC technique still require specialized oncological centers.

Strategies to prevent peritoneal carcinomatosis arising from colorectal cancer

In the last decades, cytoreductive surgery combined with hyperthermic intraperitoneal chemotherapy became a curative option for peritoneal metastases in selected patients, otherwise considered for palliative therapy alone. Better knowledge of physiopathology of peritoneal spread and identification of predictive factors for peritoneal relapse prompted specialized centers to investigate the role of a 'proactive approach' in order to early detect peritoneal metastasis. These encouraging data could justify an active attitude in selected patients at high risk of peritoneal recurrence after curative resection of primary tumor. Selection criteria and the timing of complementary hyperthermic intraperitoneal chemotherapy remain important points of discussion. In this article, we will discuss treatment principles and future perspectives to early treat and, if possible, to prevent peritoneal dissemination after curative treatment of colorectal cancer.

Adhesion molecules in peritoneal dissemination: function, prognostic relevance and therapeutic options

Peritoneal dissemination is diagnosed in 10–25 % of colorectal cancer patients. Selected patients are treated with cytoreductive surgery and hyperthermic intraperitoneal chemotherapy. For these patients, earlier diagnosis, optimised selection criteria and a personalised approach are warranted. Biomarkers could play a crucial role here. However, little is known about possible candidates. Considering tumour cell adhesion as a key step in peritoneal dissemination, we aim to provide an overview of the functional importance of adhesion molecules in peritoneal dissemination and discuss the prognostic, diagnostic and therapeutic options of these candidate biomarkers. A systematic literature search was conducted according to the PRISMA guidelines. In 132 in vitro, ex vivo and in vivo studies published between 1995 and 2013, we identified twelve possibly relevant adhesion molecules in various cancers that disseminate peritoneally. The most studied molecules in tumour cell adhesion are integrin α2β1, CD44 s and MUC16. Furthermore, L1CAM, EpCAM, MUC1, sLe^x and Le^x, chemokine receptors, Betaig-H3 and uPAR might be of clinical importance. ICAM1 was found to be less relevant in tumour cell adhesion in the context of peritoneal metastases. Based on currently available data, sLe^a and MUC16 are the most promising prognostic biomarkers for colorectal peritoneal metastases that may help improve patient selection. Different adhesion molecules appear expressed in haematogenous and transcoelomic spread, indicating two different attachment processes. However, our extensive assessment of available literature reveals that knowledge on metastasis-specific genes and their possible candidates is far from complete.

Intra-operative peritoneal lavage for colorectal cancer

Free cancer cells can be detected in peritoneal fluid at the time of colorectal surgery. Peritoneal lavage in colorectal surgery for cancer is not used in routine, and the prognostic significance of intraperitoneal free cancer cells (IPCC) remains unclear. Data concerning the technique of peritoneal lavage to detect IPCC and its timing regarding colorectal resection are scarce. However, positive IPCC might be the first step of peritoneal spread in colorectal cancers, which could lead to early specific treatments. Because of the important heterogeneity of IPCC determination in reported studies, no treatment have been proposed to patients with positive IPCC. Herein, we provide an overview of IPCC detection and its impact on recurrence and survival, and we suggest further multi-institutional studies to evaluate new treatment strategies.

Prognostic significance of isolated tumor cells in patients with colorectal cancer in recent 10-year studies

Circulating tumor cells (CTCs) that detach from the primary tumor and move into the circulation are detected in patients with metastatic cancer. The discovery of such cancer cells has been used as a predictor of recurrence and prognosis, although a consensus regarding such applications has not been reached. Peritoneal cytology may be used for identifying high risk of recurrence or mortality, whereas the intraoperative presence of tumor cells in drainage veins, bone marrow, or the liver is not always useful for evaluating the prognosis. The reported positive rate for tumor cells in the peripheral blood of patients with colorectal cancer, including metastasis, has varied from 10 to 80%; however, numerous studies have demonstrated significant differences in the recurrence and mortality rates between patients with and without isolated tumor cells (ITCs) in the peripheral blood. However, the clinical significance of CTCs as an absolute prognostic factor has not been elucidated, since the measurement methodologies and/or the number of cases differed between the studies. Future prospective studies including larger patient populations may elucidate the utility of routine detection of ITCs in daily practice.

Lack of prognostic significance of conventional peritoneal cytology in colorectal and gastric cancers: results of EVOCAPE 2 multicentre prospective study

AIM

In digestive cancers, the prognostic significance of intraperitoneal free cancer cells remains unclear (IPCC). The main objective of this study was to assess the prognostic significance of IPCC in colorectal and gastric adenocarcinoma. The secondary objectives were to evaluate the predictive significance of IPCC for the development of peritoneal carcinomatosis (PC) and to evaluate the prevalence of synchronous PC and IPCC.

METHODS

This was a prospective multicentre study. All patients undergoing surgery for a digestive tract cancer had peritoneal cytology taken. Patients with gastric and colorectal cancer with no residual tumour after surgery and no evidence of PC were followed-up for 2 years. The primary end point was overall survival.

RESULTS

Between 2002 and 2007, 1364 patients were enrolled and 956 were followed-up over 2 years. Prevalence of IPCC was 5.7% in colon cancer, 0.6% in rectal cancer and 19.5% in gastric cancer. The overall 2-year survival rate for patients with IPCC was 34.7% versus 86.8% for patients with negative cytology (p<0.0001). By multivariate analysis, IPCC was not an independent prognostic factor. No relationship between cytology and recurrence was found.

CONCLUSION

The presence of IPCC was not an independent prognostic and didn't add any additional prognostic information to the usual prognostic factors related to the tumour (pTNM and differentiation). Moreover the presence of IPCC detected with this method didn't appear to predict development of PC. Peritoneal cytology using conventional staining doesn't seem to be a useful tool for the staging of colorectal and gastric cancers.

Impact of positive intraabdominal lavage cytology on the long-term prognosis of colorectal cancer patients

BACKGROUND

Our aim was to investigate the presence of free cancer cells found in lavage cytology specimens taken from the proximity of tumors during the course of curative open and laparoscopic colorectal resections and then examine and compare the long-term disease outcomes in cases of negative and positive cytology. Based on the results, we were hoping to identify the place of peritumoral lavage cytology among prognostic factors for disease recurrence.

METHODS

Between January 1, 2005 and December 31, 2007 intraoperative peritoneal lavage cytology was performed in 145 patients who underwent curative colorectal procedures. In all, 37 of the procedures were laparoscopic resections.

RESULTS

Malignant cells were detected in the intraoperative peritoneal lavage cytology samples from 25 patients. Median follow-up was 47 months (3-81 months). Among the 25 patients with positive cytology; locoregional recurrence or distant metastasis was found in 14 during this period (56 %), whereas among the 120 patients with negative cytology the incidence was 28 (23 %).

CONCLUSIONS

The impact of tumor stage, lymph node status, and peritoneal lavage cytology on recurrence rates is significant. Tumor, nodal, and lavage cytology status can be organized hierarchically in relation to time of recurrence. Cytology is most important, with positivity rendering long-term prognosis unfavorable. When comparing surgical techniques (open versus laparoscopic), we found no significant difference in recurrence rates. Our study has shown that conventional peritoneal lavage cytology is a prognostic factor in the case of patients undergoing curative colorectal operations.

Systematic review and meta-analysis of intraoperative peritoneal lavage for colorectal cancer staging

BACKGROUND

Intraperitoneal cancer cells are detectable at the time of colorectal cancer resection in some patients. The significance of this, particularly in patients with no other adverse prognostic features, is poorly defined. Consequently peritoneal lavage is not part of routine practice during colorectal cancer resection, in contrast with other abdominal malignancies. The aim of this systematic review was to determine the effect of positive intraoperative peritoneal cytology on cancer-specific outcomes in colorectal cancer.

METHODS

A systematic review of key electronic journal databases was undertaken using the search terms 'peritoneal cytology' and 'colorectal' from 1980 to 2012. Studies including patients with frank peritoneal metastasis were excluded. Meta-analysis for overall survival, local/peritoneal recurrence and overall recurrence was performed.

RESULTS

Twelve cohort studies (2580 patients) met the inclusion criteria. The weighted mean yield was 11·6 (range 2·2-41) per cent. Yield rates were dependent on timing of sampling (before resection, 11·8 per cent; after resection, 13·2 per cent) and detection methods used (cytopathology, 8·4 per cent; immunocytochemistry, 28·3 per cent; polymerase chain reaction, 14·5 per cent). Meta-analysis showed that positive peritoneal lavage predicted worse overall survival (odds ratio (OR) 4·26, 95 per cent confidence interval 2·86 to 6·36; P < 0·001), local/peritoneal recurrence (OR 6·57, 2·30 to 18·79; P < 0·001) and overall recurrence (OR 4·02, 2·24 to 7·22; P < 0·001).

CONCLUSION

Evidence of intraoperative peritoneal tumour cells at colorectal cancer resection is predictive of adverse cancer outcomes.

Prognostic significance of detection of microscopic peritoneal disease in colorectal cancer: a systematic review

BACKGROUND

Free intraperitoneal tumour cells are an independent indicator of poor prognosis, and are encorporated in current staging systems in upper gastrointestinal cancers, but not colorectal cancer. This systematic review aimed to evaluate the role and prognostic significance of positive peritoneal lavage in colorectal cancer.

METHODS

A search was undertaken of PUBMED/Medline and Cochrane databases for English language articles from 1990 to 2012 using a predefined search strategy. Both detection of free tumour cells and/or detection of tumour-associated antigens in peritoneal lavage fluid were considered a positive lavage. Primary endpoints were rates of positive lavage, recurrence and survival.

RESULTS

Of 3805 articles identified by title, 18 met inclusion criteria (n = 3197 patients, 59.5% colon, 40.5% rectal cancer). There was heterogeneity across studies in method of detection of peritoneal disease with 7 studies using more than one method (conventional cytology (14 studies), immunological techniques (6 studies), molecular techniques (4 studies)). The rate of positive lavage varied from 2.1% to 52% across studies, with a weighted mean rate of positive lavage of 13.17% overall (95% CI 12.74-13.59). In 10 studies (n = 2017) positive peritoneal lavage was associated with worse survival, and with increased recurrence in 12 (n = 2371). Clinicopathological factors frequently associated with positive lavage included macroscopic peritoneal disease, increasing tumour stage and nodal disease.

CONCLUSION

Positive peritoneal lavage is a negative prognostic factor in colorectal cancer. However, its utility in staging colorectal cancer is currently limited by wide variation in rates of positive lavage between studies due to differences in methods of peritoneal lavage fluid analysis.

Prognostic significance of peritoneal lavage cytology in patients with colorectal cancer

BACKGROUND

The clinical significance of peritoneal lavage cytology for patients with gastric cancer is recognized, whereas that for patients with colorectal cancer remains controversial. The present study used a nationwide registry to clarify the prognostic significance of peritoneal lavage cytology in patients with colorectal cancer.

METHODS

We retrospectively analyzed factors associated with recurrence and survival in patients with T3-T4 colorectal cancer without distant metastasis taken from the nationwide registry of the Japanese Society for Cancer of the Colon and Rectum between 1984 and 1999.

RESULTS

Among 34,554 patients in this study, not all of whom received peritoneal lavage cytology, 35 had positive peritoneal lavage cytology. Gender (P = 0.0004), tumor location (P < 0.0001), histological grade (P < 0.0001), depth of tumor invasion (P < 0.0001), lymph node metastasis (P < 0.0001) and peritoneal cytology (P = 0.015) were risk factors for peritoneal recurrence. Multivariate analysis revealed that tumor location (P < 0.0001), histological grade (P < 0.0001), depth of tumor invasion (P < 0.0001) and lymph node metastasis (P < 0.0001) were independent risk factors for peritoneal metastasis. Gender (P < 0.0001), tumor location (P < 0.0001), age (P < 0.0001), histological grade (P < 0.0001), depth of tumor invasion (P < 0.0001), lymph node metastasis (P < 0.0001) and peritoneal cytology (P = 0.0004) were independent prognostic factors according to the Cox proportional hazards model.

CONCLUSION

Positive peritoneal lavage cytology was associated with poorer survival in patients with stage II and III colorectal cancer. Positive cytology might be a good indicator of candidates for intensive adjuvant chemotherapy. The benefit of intensive adjuvant chemotherapy for such patients should be validated in prospective trials.

Connective tissue growth factor acts as a therapeutic agent and predictor for peritoneal carcinomatosis of colorectal cancer

PURPOSE

Here, we aimed to investigate the role of connective tissue growth factor (CTGF) in peritoneal carcinomatosis (PC) associated with colorectal cancer (CRC) and to characterize the underlying mechanism of CTGF mediating adhesion.

EXPERIMENTAL DESIGN

A cohort of 136 CRC patient specimens was analyzed in this study. CRC cell lines were used for in vitro adhesion assay and in vivo peritoneal dissemination experiment. Recombinant CTGF protein treatment, transfection of CTGF expression plasmids, and knockdown of CTGF expression in CRC cells were utilized to evaluate the integrin α5, which served as a target of CTGF in inhibiting peritoneal seeding.

RESULTS

The analysis of CRC tissues revealed an inverse correlation between CTGF expression and prevalence of PC. Lower CTGF level in CRC patients was associated with higher peritoneal recurrence rate after surgery. Inducing CTGF expression in cancer cells resulted in decreased incidence of PC and increased rate of mice survival. The mice received intraperitoneal injection of recombinant CTGF protein simultaneously with cancer cells or following tumor formation; in both cases, peritoneal tumor dissemination was found to be effectively inhibited in the mouse model. Functional assay revealed that CTGF significantly decreased the CRC cell adhesion ability, and integrin α5 was confirmed by reverse transcriptase PCR and functional blocking assay as a downstream effector in the CTGF-mediated inhibition of CRC cell adhesion.

CONCLUSIONS

CTGF acts as a molecular predictor of PC and could be a potential therapeutic target for the chemoprevention and treatment of PC in CRC patients.

Lack of prognostic role of pre- and postoperative peritoneal cytology and cytokeratin PCR-expression on local recurrence after curative anterior resection for mid-low rectal cancer

Local recurrence continues to be a major problem in rectal cancer. After cancer removal, detection of viable cancer cells could be useful to identify patients at risk for local recurrence. Thus, aim of the study was the detection of residual peritoneal cancer cells with a possible prognostic role for local recurrence. Twenty-nine patients were operated (R0) for low (extraperitoneal) rectal cancer, without neoadjuvant radiochemotherapy. Before and immediately after cancer removal, a peritoneal lavage was done to evaluate by RT-PCR the cytokeratin 20 mRNA on isolated cells and in order to detect cancer cells by the Thin-prep test. After a median follow-up of 39 months, 5 patients died (17%), one for non-cancer-related disease, two (7%) for local recurrence and peritoneal carcinosis, and two for distant metastases. Preoperative cytology with Thin-prep test was positive in 4 patients (14%), while postoperative peritoneal cytology was positive only in 1 patient, different from the previous. No patient developed local or distal recurrence and all were disease-free at the end of the follow-up. RT-PCR analysis was positive on the peritoneal lavage after cancer removal in 11 patients. One died for unrelated cause and no one developed local recurrences. Local recurrence occurred in only 1 of the 2 patients with positive RT-PCR analysis on the first lavage and negative on the second lavage. Our study demonstrates a not important prognostic role of Thin-prep test and RT-PCR of cytokeratin 20 mRNA on the detection of patients at risk for local recurrence after curative resection of rectal cancer.

Water: a simple solution for tumor spillage

BACKGROUND

Although often proposed as a means to reduce the harmful consequences of tumor spill, water lavage has yet to be systematically evaluated in relevant in vitro and in vivo models. This study evaluates the mechanisms and utility of a single water lavage to improve the sequelae of tumor spill during laparotomy.

METHODS

Murine colorectal tumor cell susceptibility to water-induced osmotic lysis was characterized in vitro. A reproducible model of tumor spill was established to recapitulate water or saline lavage during laparotomy. Analyses of tumor volumes calculated from noninvasive imaging were performed. The tumor volumes and survival of mice treated with water, normal saline, or sham laparotomy were assessed.

RESULTS

Significant osmotic lysis of cultured murine colorectal cancer cells was observed after a brief exposure to water. Compared to saline or sham laparotomy, water lavage demonstrated superior clinical outcomes with a decrease in tumor burden and concomitant improvement in survival.

CONCLUSIONS

The use of water lavage during oncologic surgeries to reduce the sequelae of tumor spill is justified and strongly supported by our study. Data from our study raise several concerns regarding the mechanisms and efficacy of saline lavage. Clinically, the use of water lavage during laparotomy would be anticipated to reduce peritoneal disease burden with minimal toxicity or cost.

[Pleural metastases from bronchial carcinoma: is a cure possible?]

INTRODUCTION

The 2009 TNM classification of lung cancer reclassified patients with pleural invasion from stage IIIB (T4) to stage IV (M+). However, the 2009 TNM separates patients with pleural metastases (M1a) from patients with others visceral metastases (M1b), the patients with stage M1a having the better prognosis.

CASE REPORTS

Two cases are reported of patients with non-small cell lung cancer (NSCLC) metastatic to the pleura, having a long disease free survival (50 and 34 months).

CONCLUSIONS

Patients with pleural metastases from NSCLC seem to have a better prognosis than other patients with stage IV disease, maybe because of a subgroup of patients with long survival. This long survival is probably related to specific biological characteristics of certain pleural disorders that need to be identified. This would allow a more aggressive treatment of this subgroup of patients regarded today as incurable.

Effects of intraperitoneal chemotherapy with mitomycin C on the prevention of peritoneal recurrence in colorectal cancer patients with positive peritoneal lavage cytology findings

BACKGROUND

The detection of intraperitoneal free cancer cells in colorectal cancer (CRC) patients is associated with a poorer prognosis. The aim of this study was to investigate the effects of intraperitoneal chemotherapy (IPC) with mitomycin C (MMC) on preventing peritoneal recurrence in CRC patients with positive peritoneal lavage cytology findings.

METHODS

A total of 52 CRC patients who had no clinically confirmed peritoneal dissemination and whose status of peritoneal lavage cytology was positive were investigated. Conventional peritoneal lavage cytology was performed. Overall, 31 of the 52 patients (59.6%) were administered IPC with MMC. Before closure of the abdomen, 4 silicon catheters were inserted into peritoneal cavity. After closure, the perfusate (diluting 20 mg MMC with 500 ml saline) was instilled from the catheter, and all catheters were clumped. All catheters were opened 1 h later.

RESULTS

The mean follow-up period was 83.1 months. According to univariate analyses of all 52 patients and the subgroup of 36 patients with stage II or III tumors, patients with IPC had a significantly better peritoneal recurrence-free survival and cancer-specific survival than patients who did not receive IPC (P < 0.005). In multivariate analysis, IPC remained an independent prognostic factor for peritoneal recurrence-free survival in all patients.

CONCLUSIONS

It appears that IPC with MMC is an effective treatment to prevent peritoneal recurrence and prolong the cancer-specific survival in CRC patients without peritoneal dissemination, but who have positive peritoneal lavage cytology. It is necessary to verify the effectiveness of IPC with MMC in a prospective trial.

Prognostic value of peritoneal cytology and the combination of peritoneal cytology and peritoneal dissemination in colorectal cancer

PURPOSE

The value of positive peritoneal cytology in colorectal cancer has been controversial. In this study, we aimed to clarify the prognostic significance of peritoneal cytology and the impact of the combination of peritoneal dissemination and peritoneal cytology on the prognostic evaluation of colorectal cancer.

METHODS

From January 1997 to December 2005, intraoperative peritoneal cytology was performed on 410 patients who had at least serosal invasion.

RESULTS

Thirty-one patients (7.6%) had positive peritoneal cytology. Patients with negative cytology showed a significantly better survival rate at five years than those with positive cytology (negative cytology, 68.0%; positive cytology, 20.6%; P < 0.0001). Multivariate analysis revealed that peritoneal cytology is one of the significant prognostic factors. Sixty percent of patients with positive cytology and 30.4% of patients with negative cytology recurred (P = 0.08). Regarding the recurrence site, patients with positive cytology showed a significantly higher recurrence rate of peritoneal dissemination than those with negative cytology (P = 0.0038). Some patients with positive cytology but without evident peritoneal dissemination achieved long-term survival. Additionally, some patients with macroscopic peritoneal dissemination and negative peritoneal cytology also achieved long-term survival. But for those patients with both positive cytology and evident macroscopic peritoneal dissemination, the five-year survival rate was zero.

CONCLUSIONS

Patients with negative peritoneal cytology had a significantly better five-year survival rate than those with positive peritoneal cytology. In some cases in which either peritoneal cytology or peritoneal dissemination was negative, long-term survival could be achieved.

Evaluation of intraperitoneal lavage cytology before colorectal cancer resection

PURPOSE

The aim of this study was to assess the usefulness of intraperitoneal lavage cytology (lavage Cy) status before the resection of colorectal cancer as a predictive factor of peritoneal recurrence.

MATERIALS AND METHODS

The lavage Cy-positive [lavage Cy (+)] rate, peritoneal recurrence rate, and 5-year survival rate were examined in 298 cases of colorectal cancer in relation to various clinicopathological factors.

RESULTS

The overall lavage Cy (+) rate was 6.0%. The lavage Cy (+) rate within the group with peritoneal and hepatic metastases was significantly higher than that in the group without metastases (46.7% vs. 3.9% and 26.9% vs. 4.0%, respectively). The lavage Cy (+) rate was not significantly associated with any of the clinicopathological factors examined. The peritoneal recurrence rate was higher in the lavage Cy (+) group than in the lavage Cy-negative [lavage Cy (-)] group, although the difference was not statistically significant. There was no significant difference in survival, regardless of the lavage Cy status, among the 263 patients who underwent curative resection.

CONCLUSION

The lavage Cy status before resection was not a useful predictive factor of peritoneal recurrence in cases of colorectal cancer.

Prognostic significance of peritoneal tumour cells identified at surgery for colorectal cancer

BACKGROUND

The prognostic significance of intraperitoneal tumour cells (IPCs) in colorectal cancer is not clear. This study aimed to determine whether detection of IPCs could be used a prognostic marker for selecting patients at high risk of recurrence.

METHODS

The study included 226 patients with colorectal cancer who underwent elective resection. Clinical variables, including the presence of IPCs, were analysed for their prognostic significance.

RESULTS

Thirty-three patients (14.6 per cent) were positive for IPCs. Univariable analysis indicated that the presence of IPCs was a significant prognostic factor in patients with stage III colorectal cancer; the 5-year disease-specific survival rate was 14 per cent in IPC-positive patients versus 79 per cent in those without IPCs (P < 0.001). Multivariable analysis showed that IPC positivity was the most robust prognostic factor in stage III disease (hazard ratio 2.2; P = 0.003), whereas nodal category (N1 or N2) showed no significant association with prognosis. In addition, IPCs were associated with haematogenous recurrence (P = 0.004) rather than peritoneal or local recurrence (P = 0.077) in patients with stage III disease.

CONCLUSION

The presence of IPCs is a significant prognostic factor in patients with stage III colorectal cancer.

Long-term prognostic value of conventional peritoneal lavage cytology in patients undergoing curative colorectal cancer resection

PURPOSE

Free malignant cells in the peritoneal cavity might play a role in the metastasis process. However, this phenomenon needs further elucidation. The aims of this study were to investigate the frequency of free cancer cells detected on cytologic examination of lavage fluid after peritoneal washing in patients undergoing curative surgery for colorectal cancer, to explore risk factors for exfoliation of cancer cells into the peritoneal cavity, and to evaluate the influence peritoneal lavage cytology as a prognostic tool.

METHODS

Peritoneal lavage was performed in 697 patients undergoing curative resection of colorectal cancer. Before the manipulation of the tumor, 100 mL of physiologic saline solution was administered into the abdominal cavity and the fluid was collected for cytologic examination. Specimens were classified as positive if at least one cancer cell was detected.

RESULTS

The mean follow-up period was 90.5 months. Overall, 15 (2.2%) of the 697 patients had positive results. Four characteristics were identified as risk factors for exfoliation of cancer cells into the peritoneal cavity: 1) depth of invasion, 2) regional lymph nodes, 3) lymphatic invasion, and 4) venous invasion. In univariate analyses of all 697 patients and the subgroup of 374 patients with pT3 or T4 tumors, patients with positive cytology findings had significantly worse disease-free and cancer-specific survival than patients with negative cytology findings (P < 0.001). On multivariate analysis, peritoneal cytology remained an independent predictor of cancer-specific survival in all patients and in patients with pT3 or pT4 tumors. Only peritoneal cytology was a significant prognostic factor for peritoneal recurrence (P < 0.0001).

CONCLUSION

Conventional peritoneal cytology is a useful prognostic tool in patients undergoing curative surgery for colorectal cancer and may be helpful in making decisions whether to select intraperitoneal or systemic chemotherapy.

Prognostic value of CEA and CA 19-9 tumor markers combined with cytology from peritoneal fluid in colorectal cancer

BACKGROUND

Early diagnosis and management of peritoneal metastases from colorectal cancer patients are difficult clinical challenges. The aims of this study were to evaluate the clinical significance of tumor markers and cytology in peritoneal effusions (PE) and peritoneal irrigation fluid (PI) and to determine their value as prognostic indicators in this disease.

METHODS

Two hundred thirty-four consecutive patients who underwent abdominal surgery for colorectal cancer from January 2006 to December 2007 were included, and tumor markers and cytology in PE and PI were analyzed prospectively.

RESULTS

The incidence of free cancer cells retrieved from peritoneal samples was 7.9%. Cytology was positive in 40.0% by Papanicolaou and Giemsa staining, 73.3% by hematoxylin and eosin staining of cell blocks, and 66.7% by carcinoembryonic antigen (CEA) and calretinin immunohistochemistry. Multivariate analysis revealed that peritoneal CEA and cancer antigen (CA) 19-9 in PI were correlated with peritoneal metastasis and cytology. Level of peritoneal fluid CEA was statistically significantly correlated with recurrence and peritoneal metastatic recurrence in patients with negative peritoneal cytology. Cytology, peritoneal CEA, and peritoneal CA 19-9 showed correlations with cancer-free survival and overall survival.

CONCLUSIONS

These correlations demonstrate the importance of continuous follow-up of peritoneal metastasis if there is positive cytology or an increase in CEA and CA 19-9 in peritoneal fluid.

Clinical significance of telomerase activity in peritoneal disseminated cells: gastrointestinal cancers

Early detection and accurate staging of gastrointestinal (GI) cancers are difficult. The aim of this study was to evaluate whether telomerase activity (TA) in exfoliated/disseminated epithelial cells could be used as a reliable marker for GI cancers. TA was evaluated with the real-time RTQ-TRAP in immunomagnetically sorted peritoneal epithelial cells from 60 patients undergoing surgical treatment. Thirty-two patients were clinically diagnosed with a variety of GI cancers: 1 had premalignant disease, 2 had history of GI cancers, and 25 patients were clinically negative for cancer. Here we report that all types and all cases of gastrointestinal cancers were telomerase positive, thereby demonstrating 100% sensitivity for cancer. Eighteen of 25 nonmalignant cases had undetectable levels of TA, 2 had low, and 5 of 25 expressed high TA levels. Because normal epithelial cells usually have low TA and a lesser tendency to exfoliate compared with cancer cells, it is of great importance to have close follow-up for these patients to exclude possible malignant disease. We conclude that RTQ-TRAP assessment of TA in immunomagnetically sorted peritoneal epithelial cells has 100% sensitivity and 100% negative predictive value for GI cancers, and therefore, can be considered as a valuable tool and useful addition to current standard diagnostic methods. Clinical significance of unusually high telomerase activity in some clinically negative for cancer cases requires further study.

Can intra-operative intraperitoneal free cancer cell detection techniques identify patients at higher recurrence risk following curative colorectal cancer resection: a meta-analysis

BACKGROUND

Accurate staging of colorectal cancer is important for predicting prognosis and guiding treatment. This study uses meta-analysis to investigate if the pre- or post-resection detection of intraperitoneal free cancer cells can predict recurrence in patients undergoing curative colorectal cancer surgery.

METHODS

A literature search was performed on all studies between January 1990 and July 2007 comparing the detection of intraperitoneal free cancer cells either pre- or post-resection with prognosis in colorectal cancer. The following prognostic outcomes were meta-analyzed: overall recurrence rate and local recurrence rate. A random-effect model was used and heterogeneity was assessed.

RESULTS

Nine studies reporting on a total of 1182 subjects matched the selection criteria. Free cancer cells were detected prior to tumor resection in 125/822 (15.2%) of patients and following resection in 64/533 (12%) of patients. Preresection, the absence of tumor cells was associated with a lower overall recurrence (25.2%) compared to the presence of tumor cells [46.4%, odds ratio (OR) = 0.41, confidence interval (CI) 0.19-0.88]; as well as a significantly lower local recurrence (12.2% versus 21.1%, OR = 0.42, CI 0.21-0.82). Postresection, the absence of tumor cells also resulted in significantly lower overall recurrence (17.3%) when compared to the presence of tumor cells (52.6%, OR = 0.07, CI 0.03-0.18).

CONCLUSIONS

The detection of intraperitoneal free cancer cells is associated with higher recurrence and poorer prognosis. Use of these techniques can identify patients at higher recurrence risk. This could be particularly valuable in stage II disease to identify patients who may benefit from adjuvant chemotherapy.

Peritoneal cytology in colorectal cancer: incidence and prognostic value

BACKGROUND

The value of peritoneal washing cytology on prognosis is not clear yet. The aims of our prospective study were to consider the incidence and prognostic value of peritoneal cytology.

METHODS

From 1996 to 2003, washing cytology was performed in 88 patients who underwent surgery for colorectal cancer. Before exploration and manipulation of the tumor, each of the peritoneal cavities next to the tumor site, subhepatic and rectovesical recesses, were irrigated with 50 mL saline, and then the aspirates were taken for cytological evaluation.

RESULTS

Thirteen (14.7%) of 88 patients had positive cytology. Although necrosis, depth of invasion, differentiation of the tumor, macroscopic peritoneal dissemination, and ascites were correlated with positive cytology; multivariate analyses revealed the depth of invasion, presence of necrosis, and differentiation of the tumor as the factors affecting the cytology. The disease-free and overall-survival times in patients with positive and negative peritoneal washing cytology were 56.36, 61.40 and 52.08, 63.94 months, respectively (P > .05).

CONCLUSION

The presence of free malignant cells in the peritoneal cavities of patients who underwent curative resection for colorectal cancer provides no further prognostic value over the current staging systems.

Comparative analysis of intraperitoneal minimal free cancer cells between colorectal and gastric cancer patients using quantitative RT-PCR: possible reason for rare peritoneal recurrence in colorectal cancer

Peritoneal recurrence has a much lower incidence in colorectal cancer (CRC) patients than gastric cancer (GC) patients. The aim of this study is to clarify the reason for the rare peritoneal recurrence in CRC as compared with GC. The incidence and the abundance of free tumor cells in the peritoneal lavages from 102 CRC and 126 GC patients who underwent curative surgery were assessed by quantitative reverse transcription-polymerase chain reaction (qRT-PCR) with carcinoembryonic antigen (CEA) and cytokeratin 20 (CK20) as genetic markers. Prognostic significance of CEA and CK20 mRNA was also compared between CRC and GC after 2 years of follow-up by Kaplan-Meyer method with overall and peritoneal recurrence-free survival as endpoints. Positivity rate and average values of CEA and CK20 mRNA in peritoneal lavages of CRC patients, which are correlated to the depth of tumor invasion (pT category), were essentially the same as those of GC cases. Overall survival was significantly (marginally) worse in CEA mRNA (CK20 mRNA)-positive CRC patients than negatives like GC. However, peritoneal recurrence-free survival was not different between CEA (CK20) mRNA-positive and -negative CRC patients, in quite contrast to GC cases. Multivariate analysis showed that CEA mRNA was an independent prognostic factor for overall survival in GC patients, but not in CRC patients. These results suggest that the rare peritoneal recurrence in CRC patients is not due to the low incidence or the small number of intraperitoneal free cancer cells, but more likely reflects due to the low-peritoneal metastatic potential of CRC cells.

[Minimal residual tumor in gastrointestinal carcinoma. Relevance to prognosis and oncologic surgical consequences]

Isolated tumor cells as a consequence of minimal residual disease are often not detectable by routine diagnostic procedures. However, before or after surgery, isolated tumor cells in lymph nodes, the peritoneal cavity, blood, or bone marrow can frequently be identified by immunohistochemical or molecular methods. Failure to reveal the presence of such cells results in under-staging of tumor patients and may constitute the source of unexpected tumor recurrence after radical surgery. These facts emphasize the importance of isolated tumor cells at least as a surrogate marker. The frequency of appearance of isolated tumor cells in different organ systems also depends on the type of primary tumor. Developments in modern detection methods have led to increasing sensitivity but at the expense of specificity. Isolated tumor cells demonstrate remarkable heterogeneity with respect to proliferative potential and tumorigenicity. This characteristic is also reflected by a striking variability in the expression of various genes conditioning the aforementioned biological behavior. Unfortunately there is also remarkable heterogeneity in methods used for sampling and processing patient material as well as for the enrichment and detection of isolated tumor cells. Despite the ongoing controversies concerning detection methods and biological significance of isolated tumor cells, several clinical trials providing data supporting the prognostic relevance of minimal residual disease should also be considered for gastrointestinal carcinoma. In future this finding should be integrated in the planning of trials in surgical oncology, and "minimal residual disease" should receive stronger attention as a stratification criterion in such clinical studies.

Prognostic significance of CEA levels and positive cytology in peritoneal washings in patients with colorectal cancer

OBJECTIVE

The aims of this prospective study were to determine carcinoembryonic antigen (CEA) levels and incidence of cytology in peritoneal washings of patients with colorectal cancer, correlate the results with various histopathological factors and determine their significance as prognostic factors of the disease.

METHODS

From 1992 to 1999, 98 patients with adenocarcinoma of the colon or intraperitoneal rectum underwent curative surgery and enrolled in this study.

RESULTS

Overall, 25 (26.3%) of 95 patients were found to have positive cytology. The proportion of patients with positive cytology was higher in the recurrence group (36.4%) than in the groups of 5-year survival and hepatic metastases (24.6% and 26.3%, respectively), but this difference was not significant. The 5-year survival group had the lowest peritoneal CEA levels compared with the other groups, but this difference was not significant. Peritoneal cytology and CEA level alone were not sensitive, specific or accurate enough indicators in predicting survival, hepatic metastases or local recurrence. The analysis of patients with positive cytology and high peritoneal CEA level revealed that their combination can predict local recurrence with accuracy of 85%.

CONCLUSIONS

The presence of free malignant cells, as detected by cytology and CEA level, in the peritoneal cavity of patients with resectable colorectal cancer had no detectable impact on survival, hepatic metastases or local recurrence rate. However, local recurrence can be predicted with accuracy of 85% in patients who have positive cytology and high peritoneal CEA level at the same time.

Peritoneal carcinomatosis of colorectal origin: incidence and current treatment strategies

OBJECTIVE

To review the literature with regard to the incidence and prognostic significance of peritoneal seeding during surgery for primary colorectal cancer (CRC), the incidence of intraperitoneal recurrence of CRC, and the current treatment strategies of established PC of colorectal origin, with special focus on cytoreductive surgery and intraperitoneal chemotherapy (IPEC).

SUMMARY BACKGROUND DATA

Although hematogenous dissemination forms the greatest threat to patients with CRC, peritoneal carcinomatosis (PC), presumably arising from intraperitoneal seeding of cancer cells, is a relatively frequent event in patients with recurrent CRC.

METHODS

The PubMed and Medline literature databases were searched for pertinent publications regarding the incidence and prognostic significance of exfoliated tumor cells in the peritoneal cavity during curative surgery for primary CRC, the incidence of intraperitoneal recurrence of CRC, and the therapeutic results of systemic chemotherapy or cytoreductive surgery followed by IPEC.

RESULTS

The incidence of peritoneal seeding during potentially curative surgery for primary CRC, as reported in 12 patient series, varied widely, from 3% to 28%, which may be explained by differences in methods to detect tumor cells. PC is encountered in approximately 7% of patients at primary surgery, in approximately 4% to 19% of patients during follow-up after curative surgery, in up to 44% of patients with recurrent CRC who require relaparotomy, and in 40% to 80% of patients who succumb to CRC. The reported median survival after systemic 5-fluorouracil-based chemotherapy for PC varies from 5.2 to 12.6 months. Median survival after aggressive cytoreductive surgery followed by (hyperthermic) IPEC in selected patients, as reported in 16 patient series, tends to be better and varies from 12 to 32 months at the cost of morbidity and mortality rates of 14% to 55% and 0% to 19%, respectively. One randomized controlled trial has been published confirming the superiority of aggressive surgical cytoreduction and intraperitoneal chemotherapy over strictly palliative treatment.

CONCLUSIONS

Peritoneal seeding of cancer cells possibly leading to PC is a rather common phenomenon in patients with CRC. Cytoreductive surgery and adjuvant (hyperthermic) IPEC have been shown to be efficacious in selected patients and should therefore be considered in patients with resectable PC of colorectal origin.

Serosal involvement in gastrointestinal cancer: its assessment and significance

There is an increasing burden upon diagnostic histopathologists to identify accurately factors of prognostic and therapeutic implication in gastrointestinal cancer. It is perhaps partly because of the use of rigid sequential staging systems, such as the Dukes' classification, that some factors, perhaps most notably involvement of surgical margins (especially in rectal cancer) and serosal involvement (particularly in oesophageal, colonic and rectal cancer), have been relatively neglected until more recently. This is surprising and concerning because both of these pathologically derived parameters strongly correlate with subsequent locoregional recurrence and, ultimately, with prognosis. Whilst the occurrence and significance of serosal involvement have been well recognized in gastric cancer for many years, relatively little attention has been paid to the phenomenon in oesophageal cancer and yet both pleural and peritoneal involvement may be comparatively commonly identified in oesophageal cancer. Serosal involvement and transperitoneal spread are also of considerable prognostic importance in primary appendiceal carcinoma. Only more recently has the significance of serosal involvement been appreciated in colonic and rectal cancer. In the colon, the phenomenon is now recognized to be one of the most important factors in predicting transperitoneal spread and overall prognosis. Furthermore, there is increasing interest in alternative novel strategies, including intraperitoneal chemotherapy and radical peritoneal surgery, as legitimate therapeutic options in many gastrointestinal cancers.