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

Advances in the management of peritoneal malignancies

Peritoneal surface malignancies (PSMs) are usually associated with a poor prognosis. Nonetheless, in line with advances in the management of most abdominopelvic metastatic diseases, considerable progress has been made over the past decade. An improved understanding of disease biology has led to the more accurate prediction of neoplasia aggressiveness and the treatment response and has been reflected in the proposal of new classification systems. Achieving complete cytoreductive surgery remains the cornerstone of curative-intent treatment of PSMs. Alongside centralization in expert centres, enabling the delivery of multimodal and multidisciplinary strategies, preoperative management is a crucial step in order to select patients who are most likely to benefit from surgery. Depending on the specific PSM, the role of intraperitoneal chemotherapy and of perioperative systemic chemotherapy, in particular, in the neoadjuvant setting, is established in certain scenarios but questioned in several others, although more prospective data are required. In this Review, we describe advances in all aspects of the management of PSMs including disease biology, assessment and improvement of disease resectability, perioperative management, systemic therapy and pre-emptive management, and we speculate on future research directions.

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.

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.

Epigenetic biomarkers of promoter DNA methylation in the new era of cancer treatment

Promoter DNA methylation, which occurs on cytosine nucleotides across CpG islands, results in gene silencing and represents a major epigenetic alteration in human cancer. Methylation-specific PCR can amplify these modifications as markers in cancer cells. In the present work, we rigorously review the published literatures describing DNA methylation in the promoters of critical tumor suppressor genes; detection of promoter DNA methylation in various body fluids permits early detection of cancer cells during perioperative courses of clinical treatment. The latest whole-genome comprehensive explorations identified excellent epigenetic biomarkers that could be detected at high frequency with high specificity; these biomarkers, which are designated highly relevant methylation genes (HRMG), permit the discrimination of tumor tissues from the corresponding normal tissues; these markers are also associated with unique cancer phenotypes, including dismal prognosis. In humans, HRMG include the CDO1, GSHR, RASSF1 and SFRP1 genes, with these markers permitting discrimination depending on the organs tested. The combination of several HRMG increased the early detection of cancer and exhibited reliable surveillance potential in human body fluids. Cancer clinics using such epigenetic biomarkers are entering a new era of enhanced decision-making with the potential for improved cancer prognosis.

Critical relevance of genomic gains of PRL-3/EGFR/c-myc pathway genes in liver metastasis of colorectal cancer

The PRL-3 gene is involved in the liver metastasis of colorectal cancer (CRC) and oncogene addiction to anticancer therapy. In the present study genomic gains in PRL-3 and its pathway genes, c-myc and EGFR, were investigated in order to determine their clinical relevance during metastatic formation in primary CRC and corresponding liver metastases. The genomic gain statuses of PRL-3, EGFR, and c-myc were investigated using quantitative polymerase chain reaction (qPCR) analysis in 35 samples of CRC and corresponding liver metastases. In the primary CRC specimens, genomic gains in PRL-3, c-myc, and EGFR were observed in 4, 4, and 13 cases, respectively. A genomic gain in one gene was observed in 18 cases, and these genomic gains were mutually exclusive. In the liver metastasis specimens, genomic gains were observed in 14, 8, and 13 cases, respectively. The copy numbers of PRL-3 and c-myc were significantly higher in the liver metastases than in the primary CRC specimens (P=0.03, P=0.009, respectively). A genomic gain in PRL-3 was the most frequent gain in the liver metastases (P=0.004) and was partially redundant with a c-myc genomic gain. EGFR genomic gains were consistent between the primary CRC and the liver metastases (P=0.0000008). In addition, a genomic gain in any of the 3 genes was observed in 23 cases (66%). Among the clinicopathological factors that were assessed, an EGFR genomic gain was significantly associated with tumour size in the primary CRC and the liver metastases (P=0.04). A c-myc genomic gain was also significantly associated with the v factor of the primary tumours in the liver metastases (P<0.01). In conclusion, the genomic copy numbers of PRL-3, c-myc and EGFR were frequently characterised by aberrations in genomic gain in liver metastases from CRC; thus, these gene statuses exhibit potential for the identification of patients who are likely to respond positively to anticancer therapies.

Lauren Histology and Lymphatic Permeation are Critical Prognostic Factors in Borrmann Type I Gastric Cancer

Macroscopic Borrmann type I is relatively rare in advanced gastric cancer, and its detailed prognostic traits are unknown. Among 5172 gastric cancer patients between 1971 and 2013, 114 cases with macroscopic Borrmann type I were identified (2.2%), among which 112 displayed clinicopathologic factors. Univariate prognostic factors with statistical significance were initially selected, which were further applied to the multivariate proportional hazards model. Recently, postoperative adjuvant chemotherapy was recommended for stage II/III gastric cancer patients. Results were as follows: (1) Five-year overall survival (OS) was 66% in Borrmann type I gastric cancer. Five-year relapse-free survival (RFS) was 100%, 87.1%, and 65.5% in stage IA, stage IB, and stage II/III, respectively. (2) Multivariate proportional hazard model for OS identified lymphatic permeation [hazard ratio (HR) = 4.8–7.5, P = 0.0021] and age (HR = 2.4, P = 0.026), while the multivariate analysis for RFS identified histology (HR = 3.5, P = 0.018) and lymphatic permeation (HR = 3.5–4.7, P = 0.049) as independent prognostic factors. (3) Recurrence was recognized more in liver of the intestinal type histology. Diffuse type histology with robust lymphatic invasion was all attributed to stage II/III, which occurred largely within 1 year and exhibited 49% RFS. Recurrence pattern of Borrmann Type I gastric cancer with intestinal type histology is unique, and patients with high risk for recurrences were enriched in diffuse type histology with robust lymphatic invasion.

Intraperitoneal-Free Cancer Cells Represent a Major Prognostic Factor in Colorectal Peritoneal Carcinomatosis

BACKGROUND

Intraperitoneal-free cancer cells are considered as an important prognostic tool in gastric and ovarian cancer. However, their significance in colorectal cancer remains more controversial.

OBJECTIVE

This study aimed to determine the role of intraperitoneal-free cancer cells as a prognostic tool in the outcome in colorectal peritoneal carcinomatosis treated with curative intent by complete cytoreductive surgery.

DESIGN

This study is an analysis of a prospectively maintained database.

PATIENTS

Between 1991 and 2012, all patients treated in a single institution for colorectal peritoneal carcinomatosis by complete cytoreductive surgery with peritoneal cytology available were evaluated. Peritoneal cytology was stained in the conventional way (May Grumwald Giemsa).

RESULTS

Among a population of 162 patients treated for colorectal peritoneal carcinomatosis by complete cytoreductive surgery, 38 presented positive intraperitoneal-free cancer cells (23.5%). Systemic chemotherapy was administered to 135 patients (85%) during the preoperative course. Median follow-up was 34.5 months. Median overall survival was 19 and 44 months for positive and negative intraperitoneal-free cancer cells (p = 0.018). In multivariate analysis, Peritoneal Carcinomatosis Index and positive intraperitoneal-free cancer cells were significant prognostic factors of overall survival (HR, 2.3 (1.18-4.52), p = 0.014; HR, 1.9 (1.08-3.38), p = 0.027).

LIMITATIONS

Retrospective analysis and the long period were limitations of study.

CONCLUSION

Along with the Peritoneal Carcinomatosis Index, intraperitoneal-free cancer cells are a strong prognostic factor for patients treated with curative intent for colorectal peritoneal carcinomatosis by complete cytoreductive surgery. The presence of intraperitoneal-free cancer cells should lead to the consideration of different treatment strategies such as extensive intraperitoneal lavage, targeted intraperitoneal therapies, or repeated intraperitoneal chemotherapy.

Lymph node ratio as a novel and simple prognostic factor in advanced gastric cancer

TNM staging is no doubt the most critical prognostic factors, representing tumor (T)/lymph node metastasis (N)/distant metastasis (M) in gastric cancer. Lymph node ratio-based N system (Nr) has been repeatedly reported to be of prognostic relevance in advanced gastric cancer independent of stage in the multivariate analysis world-wide, and proposed as more sophisticated than N with regard to predicting accurate prognosis. As a result, proposed TNrM system may predict survival more accurately than the present TNM staging system for patients undergoing limited lymph node analysis. It could adjust stage migration when the lymph node number was used as staging factor. Although correlation of the number of metastatic lymph nodes and lymph node ratio is obvious, biological characteristics other than that could also have been reflected on. It may indicate how successful the operation of lymph node dissection was, or it may be revealing the potential of the patient's lymph node immune-reaction. Recently, high lymph node ratio is closely associated with EGFR expression in advanced gastric cancer. When efficiency of applying lymph node ratio as a biomarker is verified and confirmed in an expansive research, and when cancer causing molecules are identified, as well as the competence as a treatment target is studied, the new biomarker, namely, lymph node ratio, could find itself in a limelight in gastric cancer treatment in the future.

Genomic gain of the PRL-3 gene may represent poor prognosis of primary colorectal cancer, and associate with liver metastasis

PRL-3 genomic copy number is increased in colorectal cancer (CRC), and PRL-3 expression is closely associated with lymph node and liver metastasis of CRC. However, the clinical significance of PRL-3 genomic gain for CRC remains obscure. Here, PRL-3 genomic status in 109 primary CRC tumors and in 44 CRC tumors that had metastasized to the liver, was quantified using real time PCR. Association of PRL-3 genomic status with clinicopathological factors and prognosis was assessed in detail. PRL-3 genomic gain was identified in 31 primary CRC (27.4 %) and was more frequently seen in stage III than in stage II (p = 0.025). Among the clinicopathological factors assessed, PRL-3 genomic gain was significantly associated with poorly differentiated histology (p = 0.0039). Moreover, CRC patients with PRL-3 genomic gain exhibited poorer prognosis than those with no gain in stage II-IV CRC (p = 0.017). PRL-3 genomic gain was identified in 18 (41 %) of the liver metastasis tumors, and this frequency of gain was significantly increased as compared to that of the corresponding primary CRCs (11 %) (p = 0.001). Our findings suggested that PRL-3 genomic gain may represent an aggressive phenotype of primary CRC, and may associate with liver metastasis.

Neoadjuvant chemoradiation therapy using concurrent S-1 and irinotecan in rectal cancer: impact on long-term clinical outcomes and prognostic factors

PURPOSE

To assess the long-term outcomes of patients with rectal cancer who received neoadjuvant chemoradiation therapy (NCRT) with concurrent S-1 and irinotecan (S-1/irinotecan) therapy.

METHODS AND MATERIALS

The study group consisted of 115 patients with clinical stage T3 or T4 rectal cancer. Patients received pelvic radiation therapy (45 Gy) plus concurrent oral S-1/irinotecan. The median follow-up was 60 months.

RESULTS

Grade 3 adverse effects occurred in 7 patients (6%), and the completion rate of NCRT was 87%. All 115 patients (100%) were able to undergo R0 surgical resection. Twenty-eight patients (24%) had a pathological complete response (ypCR). At 60 months, the local recurrence-free survival was 93%, disease-free survival (DFS) was 79%, and overall survival (OS) was 80%. On multivariate analysis with a proportional hazards model, ypN2 was the only independent prognostic factor for DFS (P=.0019) and OS (P=.0064) in the study group as a whole. Multivariate analysis was additionally performed for the subgroup of 106 patients with ypN0/1 disease, who had a DFS rate of 85.3%. Both ypT (P=.0065) and tumor location (P=.003) were independent predictors of DFS. A combination of these factors was very strongly related to high risk of recurrence (P<.0001), which occurred most commonly in the lung.

CONCLUSIONS

NCRT with concurrent S-1/irinotecan produced high response rates and excellent long-term survival, with acceptable adverse effects in patients with rectal cancer. ypN2 is a strong predictor of dismal outcomes, and a combination of ypT and tumor location can identify high-risk patients among those with ypN0/1 disease.

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.

Peritoneal carcinomatosis in t4 colorectal cancer: occurrence and risk factors

BACKGROUND

Cytoreductive surgery with hyperthermic intraperitoneal chemotherapy improves outcome of patients with peritoneal carcinomatosis (PC) of colorectal carcinoma. Data on the occurrence of PC in T4 colorectal carcinoma are scarce. We investigated the occurrence and risk factors for PC in these patients.

METHODS

This was a retrospective cohort study of patients undergoing a first resection of a T4 colorectal carcinoma in a tertiary hospital between January 2000 and December 2007. Primary outcome was the occurrence of synchronous or metachronous PC. The association with PC and several patient and tumor characteristics was evaluated using logistic regression.

RESULTS

A total of 200 patients underwent resection of a T4 colorectal carcinoma. Median follow-up censored for death was 66 months (18-89 months). Synchronous PC was found in 46 of 200 patients (23 %) and metachronous PC in 33 of 154 patients (21 %). In univariable analysis, factors associated with PC were: age (OR 0.97; 95 % CI 0.94-0.99; P = 0.03), radical resection (OR 0.32; 95 % CI 0.11-0.91; P = 0.03), and N stage (OR 1.63; 95 % CI 1.36-2.34; P = 0.008). In multivariable analysis, only N stage was associated with PC (OR 1.62; 95 % CI 1.12-2.34; P = 0.01). This association was not significant for the 154 patients at risk for metachronous PC.

CONCLUSIONS

Around 1 in 5 patients undergoing resection of a T4 colorectal carcinoma either have PC during primary resection or develop PC during follow-up. N stage was associated with PC in the entire study population. However, none of the clinical or pathological variables were associated with the risk of metachronous PC and therefore cannot be used to develop targeted surveillance 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.

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.

HIPEC in T4a colon cancer: a defendable treatment to improve oncologic outcome?

BACKGROUND

Adequate estimation of the potential benefits of 'adjuvant' hyperthermia and intraperitoneal chemotherapy (HIPEC) in T4 patients through assessment of the burden of peritoneal carcinomatosis (PC) in T4 tumors and the risk of PC as the only metastatic site.

PATIENTS AND METHODS

Analysis of prospectively collected data on patients who underwent surgery for colon cancer (Jan 2004-Jan 2007).

RESULTS

About 379 patients (M/F = 204/175) were included, with a median age of 71.8 years (range 35.4-95.0): 39 stage I, 126 stage II, 89 stage III, 116 stage IV disease (+9 with unknown stage). The median follow-up was 34.8months [range 0.0-79.4]. The 3- and 5-year overall survival rates (OS) were 68.4% (95% confidence interval (CI) 63.9%-72.4%) and 60.3% (95%CI 55.6%-64.7%). Relapse analysis was restricted to stages II-III T3 (N = 154) and T4 tumors (N = 19) with complete relapse data, of which 13.2% developed PC. PC has a detrimental effect on OS [HR 6.3 (95%CI: 3.1-13.0, P < 0.0001)]. 50% of T4a and 20% of T4b developed PC. The 1- and 3-year PC percentage was significantly lower for T3 (4.5% and 9.3%) than T4 tumors (15.6% and 36.7%) (P = 0.008). PC was the only metastatic site in 3/15 T3 [proportion 0.20, 95%CI (0.043-0.481)] and 5/8 T4 tumors with PC [proportion 0.625, 95%CI (0.245-0.915)] (P = 0.071).

CONCLUSIONS

T4a colon tumors have a significantly higher risk of developing PC. Twenty-five percent (5/19) of stages II-III T4 tumors develop PC as the only metastatic site. This could define the possible window of opportunity for adjuvant HIPEC to prevent PC.

Intraperitoneal free cancer cells in non-gynaecological adenocarcinomas: a reproducibility study

OBJECTIVE

In recent years, therapeutic approaches including cytoreductive surgery followed by intraperitoneal chemotherapy have proven effective in peritoneal carcinomatosis of colorectal origin. If cytology is to be used to include patients in aggressive treatment regimens, it is necessary to evaluate its performance, particularly in terms of specificity. The aim of this study was to assess interobserver agreement for the detection of intraperitoneal free cancer cells (IFCCs) in patients with non-gynaecological adenocarcinomas.

METHODS

Over a 5-year period, 1223 patients were recruited in 19 French surgery departments. Peritoneal samples were examined in 14 dispersed pathology laboratories. Giemsa-stained slides were sent to a control reader blind to the previous diagnosis. Discordant cases, concordant positive results and a random selection of negative concordant cases were reviewed by a panel of seven cytopathologists. The 'final diagnosis' was that of the consensus meetings but took into account locally-processed slides.

RESULTS

Gathering dubious cases with negative results, a 95.6% concordance was achieved between local readers and the control reader. IFCCs were ascertained by the panel in 85 cases (7.0%). Eight of 873 colorectal cancers cases viewed locally were falsely positive (0.9%). Radiotherapy and neoadjuvant therapy had no impact on the false-positive rate as assessed by final validation by the panel (P > 0.05). Samples initially considered as dubious were reclassified as negative by the panel in 24 of 25 cases (96.0%).

CONCLUSIONS

The panel consensus allowed reclassification of most dubious/equivocal peritoneal cytology cases, whereas clearcut distinction between benign and malignant cases was correctly achieved in almost all cases.

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.

Prognostic significance of preoperative bowel obstruction in stage III colorectal cancer

BACKGROUND

Previous studies have suggested a detrimental prognostic effect of preoperative obstruction proximal to colorectal cancer (CRC). If such a detrimental effect is preserved in each stage of advanced (stage II or III) CRC, we can identify high-risk patients.

METHODS

We enrolled 641 patients with pathologically confirmed advanced CRC (stage II, n = 207; stage III, n = 434) who had undergone curative resection of the primary lesion. The association of preoperative obstruction with clinicopathologic parameters was evaluated. Kaplan-Meier analysis and Cox proportional hazard models were used to estimate the effect of preoperative obstruction on disease-free survival in each stage.

RESULTS

Preoperative obstruction was seen in 63 patients (9.8%) (stage II, n = 16; stage III, n = 47). Multivariable analysis showed that preoperative obstruction was significantly associated with preoperative elevation of carcinoembryonic antigen level in patients with colon cancer (odds ratio = 3.59; P < 0.001), while it was correlated with poor differentiation in patients with rectal cancer (odds ratio = 3.99; P = 0.016). Preoperative obstruction was a significant prognostic factor in stage III CRC (P < 0.001), but not in stage II disease. Multivariable prognostic analysis showed that preoperative obstruction was a remnant independent prognostic factor in stage III CRC. This finding was confirmed by separate analyses of colon and rectal cancer. Preoperative obstruction was associated with systemic recurrence (P = 0.003) rather than peritoneal or local recurrence.

CONCLUSIONS

These findings suggest that preoperative obstruction may predict worse long-term prognosis in patients with stage III CRC and may be a potential clinical marker to identify patients with high-risk stage III CRC.