Detection of free malignant cells in the peritoneal cavity before and after resection of colorectal cancer

Use of ascitic CEA levels as a predictive value for distant metastasis in high-risk stage II and III colorectal cancer

PURPOSE

This study aimed to analyze the effect of ascitic carcinoembryonic antigen (CEA) levels on the long-term oncologic outcomes of colorectal cancer (CRC) following curative treatment.

METHODS

A total of 191 patients with stage II/III CRC were included. CEA was analyzed on the peritoneal fluid samples taken at the start of each surgery. Long-term oncologic outcomes were analyzed using known risk factors for recurrence in CRC.

RESULT

Multivariate analysis of recurrence showed that lymphatic invasion (hazards ratio (HR) 2.7, 95% confidence interval (CI) 1.1-7, p = 0.038), vascular invasion (HR 2.8, 95% CI 1.2-6.3, p = 0.013), mucinous cancer (HR 3.6, 95% CI 1.3-10.1, p = 0.017), and peritoneal fluid CEA exceeding 5 ng/dl (odds ratio 3.1, 95% CI 1.2-7.7, p = 0.017) were significant risk factors. There were 14 patients with liver metastasis, 11 of whom had high ascitic CEA levels and no peritoneal metastasis. Additionally, eight had lung metastasis, and seven of them had high ascitic CEA levels.

CONCLUSION

High ascitic CEA levels showed significantly lower disease-free survival and were significantly associated with distant metastasis in the lung and liver.

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.

Persistent Problems in Colorectal Cancer Reporting

Tumor stage, as determined by the Tumor, Node, Metastasis (TNM) staging system, is the single most influential factor determining treatment decisions and outcome among patients with colorectal cancer. Several stage-related elements in pathology reports consistently pose diagnostic challenges: recognition of serosal penetration by tumor (ie, pT3 vs pT4a), evaluation of regional lymph nodes, distinction between tumor deposits and effaced lymph nodes, and assessment of tumor stage in the neoadjuvant setting. This article discusses each of these issues in detail and provides practical tips regarding colorectal cancer staging.

Peritoneal Carcinomatosis: Feature of Dissemination a Review

Peritoneal carcinomatosis is a common event that develops in the natural history of many neoplastic diseases, representing a major problem encountered in cancer management. Peritoneal seedings are often associated with neoplastic ascites resulting in a source of significant discomfort to the patient. Considered in the past as a terminal condition, peritoneal carcinomatosis was approached during the last two decades as a curable disease. The introduction of cytoreductive surgery or peritonectomy in the treatment of peritoneal neoplastic diseases drastically changed the natural history of peritoneal carcinomatosis. Another technique that showed an important impact on disease control is intraperitoneal hyperthermic perfusion, one of the most fascinating treatments of peritoneal carcinomatosis that results in an impressive increase in overall survival and quality of life in treated patients with low morbidity. This review illustrates the modality of dissemination of peritoneal carcinomatosis in relation to the primary tumor site and grade of malignancy. Peritoneal carcinomatosis is a term used to define an advanced stage of many abdominal neoplastic diseases that differ in biologic aggressiveness and prognosis. The different presentation of peritoneal carcinomatosis in relation to a different primary tumor and different grade of malignancy strongly influences the potentially therapeutic radical approaches using new and advanced modalities like cytoreductive surgery and intraperitoneal hyperthermic perfusion.

Positive Peritoneal Lavage Cytology -Implications for Staging and Management of Gastric Cancer

The survival rates of gastric cancer patients with cytology-positive peritoneal lavage fluid without macroscopic dissemination (CY+/P-) is the same as that of patients with overt peritoneal metastasis.The 5-year survival rate of such patients is only 2%. The current study aims to highlight its significance in the staging of gastrointestinal malignancies and its implications for patient care. Prospective nonrandom analysis of peritoneal wash cytology in patients with gastrointestinal malignancies was conducted in the department of Surgical Gastroenterology, Nizams Institute of Medical Sciences, Hyderabad from January 2012 to June 2013. Descriptive statistics and ANOVA variance analysis was performed to estimate incidence, risk factors and the effect of surgery in causing peritoneal dissemination of malignancy. A total of 60 patients with operable gastric cancer underwent peritoneal lavage for evaluation of malignant cells. The incidence of Positive peritoneal lavage cytology was 8.3% (5/60).Four patients with positive lavage fluid belong to T3 stage (11.7%, p-0.309).Poorly differentiating and mucinous tumors had a higher incidence of positive cytology (18.1% and 25%).None of the patients with positive cytology had positive resection margin. Tumors with advanced T stage, lymph nodal involvement, lympho-vascular and perineural invasion have higher incidence of positive peritoneal cytology. Surgical handling has a negligible effect in peritoneal dissemination of tumor. Large scale studies are warranted to validate the findings and define it's role in management of gastric cancer.

Assessment of Hyperthermic Intraperitoneal Chemotherapy to Eradicate Intraperitoneal Free Cancer Cells

OBJECTIVE: To assess the effect of hyperthermic intraperitoneal chemotherapy (HIPEC) to eradicate intraperitoneal free cancer cells and to explore the feasibility of cytological cure for peritoneal carcinomatosis (PC). METHODS: The peritoneal lavage fluid (or ascites) from 50 PC patients was collected before and after intraoperative HIPEC, respectively, for conventional cytology test, and conventional and real-time quantitative reverse transcript polymerase chain reaction detecting carcinoembryonic antigen (CEA) mRNA and cytokeratin-20 (CK20) mRNA. The blood samples 3 days before and 7 days after intraoperative HIPEC were also collected for detecting the serum tumor markers, including CEA, carbohydrate antigen (CA) 125, and CA19-9. RESULTS: The positive rate of conventional cytology test before HIPEC versus after HIPEC was100.0% versus 22.0% (P = .000). The positive rates of CEA mRNA and CK20 mRNA before HIPEC versus after HIPEC were 100.0% versus 86.0% (P = .012) and 100.0% versus 96.0% (P = .495), respectively. Moreover, after HIPEC, 18 (36.0%) patients had a decline in CEA mRNA (P = .000), and 17 (34.0%) patients had a decline in CK20 mRNA (P = .000). The positive rates of serum CEA, CA125, and CA199 before HIPEC versus after HIPEC were 52.0% versus 28.0% (P = .014), 52.0% versus 44.0% (P = .423), and 40.0% versus 28.0% (P = .205), respectively. CONCLUSION: HIPEC could effectively eradicate intraperitoneal free cancer cells and partially achieve cytological cure for PC.

Peritoneal expression of Matrilysin helps identify early post-operative recurrence of colorectal cancer

Recurrence of colorectal cancer (CRC) following a potentially curative resection is a challenging clinical problem. Matrix metalloproteinase-7 (MMP-7) is over-expressed by CRC cells and supposed to play a major role in CRC cell diffusion and metastasis. MMP-7 RNA expression was assessed by real-time PCR using specific primers in peritoneal washing fluid obtained during surgical procedure. After surgery, patients underwent a regular follow up for assessing recurrence. transcripts for MMP-7 were detected in 31/57 samples (54%). Patients were followed-up (range 20-48 months) for recurrence prevention. Recurrence was diagnosed in 6 out of 55 patients (11%) and two patients eventually died because of this. Notably, all the six patients who had relapsed were positive for MMP-7. Sensitivity and specificity of the test were 100% and 49% respectively. Data from patients have also been corroborated by computational approaches. Public available coloncarcinoma datasets have been employed to confirm MMP7 clinical impact on the disease. Interestingly, MMP-7 expression appeared correlated to Tgfb-1, and correlation of the two factors represented a poor prognostic factor. This study proposes positivity of MMP-7 in peritoneal cavity as a novel biomarker for predicting disease recurrence in patients with CRC.

Correlation between peritoneal lavage cytology and tumour stage in patients with colorectal cancer

BACKGROUND AND STUDY AIMS

Complete surgical removal of the involved bowel segment in colorectal cancer is the most effective primary treatment. The main prognostic factors for colorectal cancer are penetration of the tumour into different layers of the bowel wall and regional lymph node involvement. Positive lavage cytology has been used to predict peritoneal recurrence, but its effectiveness remains controversial. This study was conducted to assess the prevalence of positive peritoneal lavage cytology in correlation with the tumour stage in patients with colorectal cancer.

PATIENTS AND METHODS

This prospective cross-sectional study was performed on 20 patients with different cases of colorectal cancer attending the colorectal unit and emergency department of the Kasr Al Ainy Hospital, Cairo University Hospitals, from March 2012 to March 2013.

RESULTS

The patients' gender did not influence the peritoneal lavage cytology results (p = 0.062); there is no significant correlation between the TNM staging system and cytology in patients with colorectal cancer (p = 0.253).

CONCLUSION

Although there is a positive linear correlation between the tumour stage and positive peritoneal lavage cytology, it did not reach a statistically significant level. In addition, the greater the depth of invasion, the higher the lavage cytology rate. However, this trend was not statistically significant.

Histologic features and cytologic techniques that aid pathologic stage assessment of colonic adenocarcinoma

Cancer involvement of the colonic serosa is designated pT4a by the American Joint Committee on Cancer Staging Manual, 7th edition. The manual defines criteria for pT4a as either tumor penetration of the serosa or comingling of cancer cells and mesothelial cells in histologic sections. Unfortunately, the pT4a grouping is inconsistently applied, because these guidelines are overly limited: fibroinflammatory changes near the serosa may be associated with peritoneal metastases even in the absence of overt peritoneal penetration. Thus, reliable ancillary techniques for detecting serosal penetration by the tumor and accurate criteria for stage assessment are needed. We evaluated the utility of cytologic preparations in determining tumor stage by comparing results of serosal scrape cytology with histologic stage assessment of 120 colon cancer resection specimens. We correlated our findings with the presence and type of inflammatory changes near the serosa to determine which, if any, are reliable indicators of peritoneal penetration. Cytologic smears from all pT1 and pT2 tumors were negative for carcinoma. However, 13 (19%) pT3 tumors showed cancer in cytologic smears, all of which were deeply invasive. In fact, 46% of pT3 cancers present ≤1 mm from a serosal tissue reaction were associated with cancer in cytologic preparations from the serosa, which was comparable to pT4a tumors (55%). We conclude that cytologic smears improve detection of peritoneal penetration among pT3 tumors compared with histology alone. Tumors close (≤1 mm) to a fibroinflammatory tissue reaction on the serosa are likely associated with peritoneal involvement by cancer. Peritumoral abscesses that communicate with the serosa and hemorrhage or fibrin on the serosa also predict cancer involvement of the peritoneum. The presence of these findings among deeply invasive cancers should prompt their classification as pT4a lesions.

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.

Isolated cutaneous metastasis of uterine leiomyosarcoma: case report and review of literature

A 54 year old lady presented for routine excision of a scalp lesion thought clinically to represent a sebaceous cyst of the right occiput. 4 years earlier she underwent total abdominal hysterectomy and right salpingo-oophorectomy for 3 large uterine fibroids. Histo-pathological examination of the hysterectomy specimen revealed an incidental low-grade leiomyosarcoma. Staging imaging was negative for metastatic disease. She made an uneventful recovery and was treated further by adjuvant pelvic radiotherapy.She noticed an uncomfortable and unsightly cystic swelling on her occiput four years after hysterectomy and was referred for routine excision of what was believed to be a benign lesion. The lesion was excised and sent for histopathological examination. Microscopic analysis including immuno-histochemistry demonstrated an ER and PR positive metastatic deposit of leiomyosarcoma. The margins of excision were histologically clear of disease.At Multi-Disciplinary Team (MDT) discussion a diagnosis of metastatic scalp deposit from previous uterine leiomyosarcoma was made. Re-staging CT brain, thorax, abdomen and pelvis and MRI brain were negative for local recurrence or distant metastases. She is currently undergoing radiotherapy to the scalp and surrounding tissues and will be followed up closely by the involved teams.To the best of our knowledge, this is the first case described in the worldwide literature of isolated cutaneous metastasis to the scalp of uterine leiomyosarcoma without evidence of disseminated disease at other sites.

VIRTUAL SLIDES

The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1311834987345566.

Isolated abdominal wound recurrence after lymph-node dissection for appendiceal adenocarcinoma

A 47-year-old man with acute abdominal pain in the right lower quadrant underwent an appendectomy via McBurney's incision. Postoperative histology revealed a moderately differentiated adenocarcinoma in the appendix that invaded the submucosa along with lymphatic involvement. Forty-three days later, an ileocecal resection with radical lymph node dissection was performed through a midline incision. Three of the 30 resected lymph nodes were found to have adenocarcinoma metastasis. Five years later, an isolated abdominal wall recurrence occurred within the wound scar of the midline incision. A complete excision of the tumor and the invaded portion of the ileum was performed. To date, the patient has been well, with no evidence of recurrence for 5 years since the resection. The mechanism of abdominal wound recurrence is considered the leakage of carcinoma cells from transected lymph vessels during lymph node dissection, followed by the implantation of these cells into the abdominal wound.

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.

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.

Promoter hypermethylation of tumor-related genes in peritoneal lavage and the prognosis of patients with colorectal cancer

BACKGROUND AND OBJECTIVES

The predictive value of free cancer cells in the peritoneal fluid of patients with colorectal cancer (CRC) remain to be elucidated. The aim of this study was to determine the prognostic relevance of the methylation of tumor-related genes detected in the peritoneal lavage fluid (PLF) of patients undergoing a resection for CRC.

METHODS

The promoter methylation pattern of four target genes, CDH1, CDKN2A (p16), MGMT, and APC, was examined in 51 primary CRC and corresponding matched PLF DNA. The relative methylation levels of these genes in primary CRC tissue and paired PLF were assessed by quantitative methylation-specific polymerase chain reaction (QMSP).

RESULTS

An aberrant methylation of at least one gene was found in 45 of 51 (88%) primary tumors. In matched PLF specimens, the frequencies of aberrant promoter methylation detected for each marker were 16% for CDH1, 2% for p16, 4% for MGMT and 24% for APC. Patients with PLF demonstrating the methylation of more than one of these four target genes demonstrated significantly shorter relapse-free survival.

CONCLUSIONS

These findings suggest that disseminated tumor cells in PLF detected by QMSP may correlate with the postoperative clinical course of patients undergoing curative surgery for CRC.

Benefits of povidone-iodine solution in colorectal operations: science or legend

Povidone-iodine solution (Betadine) has long been accepted as an effective topical broad spectrum antiseptic, disinfectant, and tumoricidal agent. In colorectal operations, this solution generally has been used for the purpose of minimizing postoperative septic complications and reducing cancer recurrence, although the optimal application, advantages, and undesirable side effects have been debated. With limited prospective, randomized, controlled trials and insufficient data available, this article examines the safe and effective clinical applications of this solution for colorectal operations.

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.

[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.

Detection of free cancer cells in peritoneal cavity in patients surgically treated for gastric adenocarcinoma

Bacground/Aim. Peritoneal metastasis is a leading cause of therapeutic failure after an operative treatment of patients with gastric adenocarcinoma. Free cancer cells might induce or indicate an early peritoneal seeding with a subsequent peritoneal metastasis. The aim of this study was to determine the frequency of the presence of free cancer cells in the peritoneal cavity in the patients surgically treated for gastric adenocarcinoma, and its relation to certain clinical, operative and pathohistological parameters. Methods. Inside a period from April 2000, and April 2004, the total of 100 patients underwent intraoperative peritoneal lavage for cytological examination. Immediately after the laparotomy, 200 ml physiologic saline, heated to 37 ?C, was introduced into the abdominal cavity, manually dispersed and collected from the region around the gastric tumor and the pouch of Douglas. The nucleated cell layer was smeared on four glass slides for every patient and dyed with May-Gr?nwald-Giemsa stain. The cytological findings were defined as positive or negative according to the presence of cancer cells. The frequency of positive cytological findings was compared to the location and the diameter of the cancer, pathohistological type of carcinoma, pathohistological stage of the disease, lymph node and the liver and/or peritoneal metastases and the type of surgical procedure. Results. Free cancer cells were found in 24 (24%) of the patients, while in 76 (76%) of them cytological findings were negative. A statistically highly significant difference (p ? 0.001) in the frequency of positive cytological finding was found between the groups of patients with and without cancer invasion of serosa, with cancer diameters > 5 cm and ? 5 cm, in the stage of disease I, II and III, IV, with macroscopically present and without metastases, with resection and D2 lymphadenectomy and palliative procedure. Free cancer cells were statistically more frequently (p ? 0.05) detected in the patients with lymph nodes metastases comparing to the patients without lymph nodes involvement. The results of the univariate analysis showed that the cancer diameter > 5 cm, tumor invasion of serosa, pathohistological stage of the disease III and IV and macroscopically visible metastases were the most important risk factors for the free cancer cells detection. Conclusion. Peritoneal lavage cytology was shown to be a useful tool for the detection of the group of patients with greatest risk of peritoneal dissemination. The frequency of positive cytological findings was highly associated with the diameter of the tumor and the cancer invasion of serosa. Cytological examination of peritoneal lavage fluid improved the accuracy of staging and selection of patients who might have benefit from neoadjuvant chemotherapy.

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.

Free colorectal cancer cells on the peritoneal surface: correlation with pathologic variables and survival

BACKGROUND

Clinicopathologic staging of colorectal cancer remains the best predictor of survival. Prognostication for an individual with colorectal cancer remains elusive. This study was designed to investigate the incidence of free surface colorectal cancer cells detected by cytology during elective open curative resection, to correlate their presence with particular clinicopathologic variables and determine whether their presence was predictive of cancer-specific survival.

METHODS

Over a six-year period in one institution, all elective colon and intraperitoneal rectal cancer specimens were assessed during primary resection for the presence of free colorectal cancer cells by means of a simple and tested specimen imprint cytology methodology. Clinicopathologic variables were assessed prospectively and blinded to cytology results. All patients were followed up routinely until death and if the patient was not seen within the last six months, information was obtained from the New South Wales Registry of Births, Deaths and Marriages in Australia.

RESULTS

Overall, 26 of 281 (9.25 percent) colorectal cancers had positive cytology for cancer cells on the peritoneal surface of the bowel. Poorly differentiated tumors were significantly associated with positive cytology. Tumor penetration, presence of vascular or neural invasion, mucinous characteristics, lymph node status, and operative procedure performed were not statistically significant predictors of positive cytology. Overall, 43 of the 281 patients (15.3 percent) died during the mean follow-up period of 49.2 months from cancer-related deaths. Of these patients, 8 had positive cytology and 35 had negative cytology results. Cancer-specific survival assessed with the log-rank test was significantly associated with positive cytology in univariate (P = 0.008) and multivariate analysis (P < 0.001).

CONCLUSION

In this study, the presence of free surface colorectal cancer cells has been shown to be predictive of survival and is independent of direct peritoneal invasion and lymph node status. Thus, further assessment of this simple prognostic variable is warranted and selection of patients with positive cytology for possible adjuvant therapies may be beneficial.

Distilled water peritoneal lavage after colorectal cancer surgery

PURPOSE

Tumor cells exfoliated into the peritoneal cavity during colorectal cancer surgery are viable and tumorigenic and may contribute to peritoneal recurrence. Although commonly used, the tumoricidal effectiveness of antiseptics in peritoneal lavage is doubted because of their chemical alteration by peritoneal secretions. In contrast, osmotic lysis by incubation in distilled water may offer an effective tumoricidal activity. Data defining the susceptibility of colorectal carcinoma cells to osmotic lysis are lacking and hence there is no consensus on optimal lavage methodology.

METHODS

We examined the cytocidal activity of water on colorectal cancer cell lines in culture and determined the effect of peritoneal secretions in vivo on the tumoricidal effectiveness of water.

RESULTS

Incubation of cells in distilled water resulted in cell lysis, with 100 percent lysis achieved after 14 minutes of incubation. In vivo, contamination of lavage water by peritoneal secretions produced a resultant solution with an osmolality of 50 mM. Sequential lavages reduced this contamination, enabling a final resultant solution with an osmolality of 10 mM, which produced 100 percent cell lysis after 32 minutes of incubation.

CONCLUSIONS

Current peritoneal lavage methodology is inadequate because complete cell lysis requires water incubation for longer time periods than is currently practiced. Solutions to this problem are discussed.

Risk factors for peritoneal dissemination of colorectal cancer

BACKGROUND AND OBJECTIVES

The aim of this study was to clarify the risk factors associated with positive peritoneal dissemination (PPD) of colorectal cancer (CRC).

METHODS

From June 2000 to September 2002, 143 CRC patients who underwent elective curative (79.0%) or non-curative (21.0%) open laparotomy were prospectively studied. Clinical evaluations including classical factors, colonoscopic evaluation, intraoperative evaluation, and pathological features were recorded. PPD was diagnosed when macro- (MAPD) or microscopic peritoneal dissemination (MIPD) was evident. Positive peritoneal cytology from initially existing ascites or washing lavage indicated MIPD. Various factors were analyzed with univariate (Chi-square test) and then multivariate analyses (logistic regression test) to search for the risk factors of PPD.

RESULTS

Overall, MIPD, MAPD, and PPD were found in 2.8%, 6.3%, and 9.1%, respectively. Univariate analysis identified age (< or =59 years), CA19-9 (> or = 34.6 U/ml), poor differentiation, circumferential involvement (> or = 3 quadrants), ascites volume (>80 ml), pN+, and pT4 as risk factors of PPD. PPD did not occur in patients with well-differentiated tumors, less circumferential involvement (< 2 quadrants), or no lymph node metastasis. After multivariate analysis, CA19-9 (Odds ratio (95% CI), 8.6 (1.7-43.1)), pT4 (9.0 (1.3-61.0)), and age (5.26 (1.1-25.0)) remained significant risk factors.

CONCLUSION

CA19-9 (> or = 34.6 U/ml), pT4, and age (< or =59 years) were significant risk factors of PPD.

Perioperative detection of disseminated tumour cells is an independent prognostic factor in patients with colorectal cancer

BACKGROUND

The objective of the present investigation was to assess the prognostic significance of disseminated tumour cells in peritoneal lavage, and peripheral and mesenteric venous blood in patients undergoing curative resection of colorectal cancer.

METHODS

The prognostic impact of perioperative cytological and immunocytochemical detection of disseminated colorectal cancer cells was evaluated prospectively. Peritoneal lavage fluid, and peripheral and mesenteric venous blood from 53 consecutive patients undergoing curative surgery for colorectal cancer were analysed. The dichotomous results (positive versus negative) from the cytological and immunocytochemical analysis were used as a predictor along with other co-variates in proportional hazard regression models of disease-free and overall survival.

RESULTS

Disseminated colorectal cancer cells were found in 13 of 53 patients (25 per cent) using cytology (CYT) and/or immunocytochemistry (ICC). The median follow-up at the time of the analysis was 37 months. In multivariate proportional hazard regression models CYT/ICC status was a significant predictor for disease-free (P = 0.002) and overall (P = 0.006) survival.

CONCLUSION

Disseminated tumour cells detected by CYT and ICC represent an independent prognostic factor in patients undergoing surgery for colorectal cancer and may identify patients at high risk of recurrence.

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

BACKGROUND

This study was undertaken to evaluate the long-term prognostic significance of conventional peritoneal cytology in patients with advanced colorectal carcinoma after curative resection.

METHODS

A review was performed of 189 patients who underwent curative resection for pT3/T4 carcinoma of the colon and upper/middle rectum between March 1987 and December 1991. Patient outcomes were reviewed retrospectively. Peritoneal cytology was performed before manipulation of the tumor. Intraoperatively, 50 ml of saline were instilled and 20 ml were reaspirated for cytology. In all patients, Papanicolaou and Giemsa stainings were performed to detect intraperitoneal free tumor cells.

RESULTS

The median follow-up was 103 months. Malignant cells were identified in peritoneal washings from 11 patients (5.8%). Of the 11 patients with positive cytology, six (54.5%) developed recurrence and peritoneal recurrence was observed in four (36.4%). In contrast, of the 178 patients with negative cytology, 46 (25.8%) developed recurrence and peritoneal recurrence was observed in four (2.2%). The peritoneal recurrence rate was significantly increased (P = 0.0004) in the patients with positive cytology. The cancer-specific 10-year survival rates for the patients with positive and negative cytology were 45.5 and 80.3%, respectively (P = 0.0051). Multivariate analysis (Cox proportional hazard model) revealed that peritoneal cytology (positive: P = 0.0256) and lymph node metastasis (pN2: P = 0.0004) were independent predictors of cancer-specific survival.

CONCLUSION

Conventional peritoneal cytology serves as a new prognostic marker after curative resection in patients with advanced colorectal carcinoma. It appears to be a useful diagnostic procedure for predicting recurrence, especially peritoneal recurrence.

[Evaluation of povidone abdominal washing for prevention of peritoneal cancer cell seeding: experimental study in the rat]

GOAL

The aim of the study was to evaluate the in vitro cytototoxicity of diluted povidone iodine on colon cancer cells and its in vivo antitumoral effect in a model of peritoneal carcinomatosis in the rat.

METHODS

Cell cytotoxicity of a povidone iodine diluted solution was assessed, in vitro, on rat colon cancer cells (DHD/K12/PROb) and human colon cancer cells (HT29). The antitumoral effect of diluted povidone iodine washing was measured in BDIX rats after the intraperitoneal inoculation of 10(6) DHD/K12/PROb cells. Results were compared to an abdominal washing within a 9 g/l salinel solution. In one experiment, peritoneal scars and a colocolic anastomosis were performed after the injection of cancer cells.

RESULTS

A short 10 min incubation of human and rat colon cancer cells with diluted povidone iodine resulted in a complete cell killing. In animals, a peritoneal washing with 1% diluted povidone iodine completely inhibited the tumor growth in parietal peritoneum. However, development of peritoneal tumor nodules was not inhibited in the omentum, in scarified peritoneum or in intestinal anastomosis.

CONCLUSIONS

Despite its high in vitro efficacy, diluted povidone iodine has an incomplete effect in the prevention of peritoneal carcinomatosis, with only a partial inhibition in scarred peritoneum epiploïc area and intestinal anastomosis. In contrary, it procures a complete inhibition of tumor growth in normal peritoneum.

TNM residual tumor classification revisited

BACKGROUND

For cancer patients, prognosis is strongly influenced by the completeness of tumor removal at the time of cancer-directed surgery or disease remission after nonsurgical treatment with curative intent. These parameters define the relative success of definitive treatment and can be codified by an additional subclassification within the TNM system, the residual tumor (R) classification. Despite the importance of residual tumor status in designing clinical management after treatment, misinterpretation and inconsistent application of the R classification frequently occur that diminish or abrogate its clinical utility.

METHODS

An analysis of the relevant literature regarding the use and prognostic importance of the R classification was undertaken.

RESULTS

In the current study, the prognostic importance of the R classification for different kinds of tumors is discussed. Problems that arise in using the R classification are described. Special issues regarding the use of the R classification are addressed.

CONCLUSIONS

The R classification is a strong indicator of prognosis and facilitates the comparison of treatment results if applied in a consistent manner. Uniform use and interpretation of this classification is essential for the standardization of posttreatment data collection.

Minimal residual disease in gastrointestinal cancer

Tumor progression after curative resection of gastrointestinal carcinomas is probably caused by pre- or intraoperative tumor cell dissemination. Disseminated tumor cells are generally detected by immunohistochemistry- or PCR-based molecular-biology methods. A consensus on which is the most adequate detection method has not yet been found, which makes the comparison of data difficult. The prognostic relevance of disseminated cells has been shown, at least in part, for esophageal, gastric, pancreatic, and colonic cancer. The data regarding hepatocellular cancer is conflicting. This article gives a critical review of tumor cell detection in gastrointestinal cancer.

Limitations of peritoneal lavage with antiseptics in prevention of recurrent colorectal cancer caused by tumor-cell seeding: experimental study in rats

PURPOSE

Exfoliated or soiled free malignant cells have serious consequences in patients undergoing gastrointestinal cancer surgery. The present study evaluates the toxicity and efficacy of cytotoxic agents in the prevention of cell seeding and tumor growth in the peritoneal cavity in an experimental model.

METHODS

Mtln3 adenocarcinoma cell viability was tested in vitro using the trypan blue exclusion test after incubation with povidone-iodine or chlorhexidine. In vivo, Fischer rats were inoculated with 10(5) or 10(6) cells followed by peritoneal lavage with physiological saline, chlorhexidine 0.02 percent, povidone-iodine low molecular weight 1 percent or povidone-iodine high molecular weight 1 and 2 percent in different quantities and incubation times.

RESULTS

Chlorhexidine 0.02 percent and povidone-iodine low molecular weight 1 percent or high molecular weight 2 percent, killed over 98 percent of 10(5) or 10(6) tumor cells in vitro. Povidone-iodine low molecular weight 1 percent and high molecular weight 2 percent were toxic and lethal when 5 ml were applied in the peritoneal cavity three times for five minutes. Chlorhexidine 0.02 percent applied after inoculation of 10(5) or 10(6) cells, reduced the tumor development only to 70 and 80 percent. Application of 5 ml povidone-iodine 1 percent low molecular weight or high molecular weight, three times for one and five minutes, after inoculation of 10(6) cells did not change the tumor take. However, inhibition of Mtln3 cells to form metastases was observed. When povidone-iodine low molecular weight 1 percent was used three times for one minute after 10(5) tumor cells were "soiled", no toxicity was observed and the tumor take was reduced to 30 percent (P < 0.05).

CONCLUSIONS

Povidone-iodine toxicity proved to be a major issue in vivo. However, povidone-iodine low molecular weight 1 percent was safe when used for short periods and very effective when a limited number of tumor cells was inoculated. The use of cytotoxic agents to prevent recurrent disease caused by tumor cell seeding in patients seems to make sense only when the "inoculum size" of exfoliated or soiled cancer cells is limited.

Rectal cancer recurrence: factors and mechanisms

OBJECTIVE

There have been significant developments in treatment for rectal carcinoma, both in surgical and adjuvant therapy. They may however have associated morbidity and hence individualized therapy for rectal cancer is desirable, to optimize treatment but avoid over-treatment for cases where the risk of recurrence is low.

MATERIALS AND METHODS

A literature review was undertaken of the reported incidence of recurrence of rectal carcinoma following curative surgery, factors which predispose to recurrence and proposed mechanisms for recurrence, and the evidence for each critically evaluated.

RESULTS

The incidence of local recurrence of rectal carcinoma following curative resection ranges from 2.6% to 32%, with an average of 15%. Tumour stage is the strongest predictor of tumour recurrence. Upstaging using molecular biology may predict increased risk of recurrence but is not yet proven. Histological factors including differentiation and vascular invasion increase recurrence but are imprecise. Tumour microvascular density and vascular endothelial growth factor (VEGF) levels may be predictive but need refinement. Adequate resection margins are important but recurrence may occur despite this. Tumour cell spillage and distant dissemination may be a mechanism for tumour recurrence following curative resection, but further research is required before this could be applied clinically.

CONCLUSION

Recurrence of rectal cancer remains a significant problem following 'curative' surgery. Multiple factors may influence recurrence risk, though currently however only tumour stage and histological resection margins have demonstrated sufficient importance for management decisions to be made upon them.

Abdominal insufflation does not cause hematogenous spread of colon cancer

BACKGROUND AND PURPOSE

Previous investigators have suggested that port-site recurrences are possibly a result of abdominal insufflation, forcing viable cancer cells into the circulation to metastasize and thrive in areas of trauma. Using a syngeneic animal cancer model, we tested the hypothesis that pneumoperitoneum increases the incidence of wound metastasis by a blood-borne mechanism.

METHODS

Male BD IX rats (N = 150) were injected intraperitoneally with 2 x 10(5) viable syngeneic 1,2-dimethylhydralazine-induced colon cancer cells (DHD-K12). Animals were divided into three groups: A (abdominal insufflation with 3-cm incision on the back into muscle remote from the peritoneum); B (3-cm back incision alone); and C (control group with 3-cm midline abdominal incision). Three weeks after surgery, the animals were euthanized and autopsied.

RESULTS

In the two groups with back wounds, the incidence of cancer growth at the incision was zero, as demonstrated grossly and by histologic sample (A: 0/47, B: 0/43). In contrast, the autopsied control group had a 42% incidence of metastasis to the wound (25/59). There seemed to be no difference in the distribution of intra-abdominal disease between those rats that underwent insufflation and those that did not.

CONCLUSION

It is unlikely that pneumoperitoneum promotes hematogenous wound implantation of free intraperitoneal cancer cells.

Prognostic value of microscopic peritoneal dissemination: comparison between colon and gastric cancer

PURPOSE

We evaluated the incidence and prognostic relevance of microscopic intraperitoneal tumor cell dissemination of colon cancer in comparison with dissemination of gastric cancer as a rational for additive intraperitoneal therapy.

METHODS

Peritoneal washouts of 90 patients with colon and 111 patients with gastric cancer were investigated prospectively. Sixty patients with benign diseases and 8 patients with histologically proven gross visible peritoneal carcinomatosis served as controls. Intraoperatively, 100 ml of warm NaCl 0.9 percent were instilled and 20 ml were reaspirated. In all patients hematoxylin and eosin staining (conventional cytology) was performed. Additionally, in 36 patients with colon cancer and 47 patients with gastric cancer, immunostaining with the HEA-125 antibody (immunocytology) was prepared. The results of cytology were assessed for an association with TNM category and cancer grade, based on all patients, and with patient survival, among the R0 resected patients.

RESULTS

In conventional cytology 35.5 percent (32/90) of patients with colon cancer and 42.3 percent (47/111) of patients with gastric cancer had a positive cytology. In immunocytology 47.2 percent (17/36) of patients with colon cancer and 46.8 percent (22/47) of patients with gastric cancer were positive. In colon cancer, positive conventional cytology was associated with pT and M category (P = 0.044 and P = 0.0002), whereas immunocytology was only associated with M category (P = 0.007). No association was found between nodal status and immunocytology in colon cancer and with the grading. There was a statistically significant correlation between pT M category and conventional and immunocytology in gastric cancer (P < 0.0015/P = 0.007 and P < 0.001/P = 0.009, respectively). Positive immunocytology was additionally associated with pN category (P = 0.05). In a univariate analysis of R0 resected patients (no residual tumor), positive immunocytology was significantly related to an unfavorable prognosis in patients with gastric cancer only (n = 30). Mean survival time was significantly increased in patients with gastric cancer with negative cytology compared with positive cytology (1,205 (standard error of the mean, 91) vs. 771 (standard error of the mean, 147) days; P = 0.007) but not in patients with colon cancer (1,215 (standard error of the mean, 95) vs. 1,346 (standard error of the mean, 106) days; P = 0.55).

CONCLUSIONS

Because microscopic peritoneal dissemination influences survival time after R0 resections only in patients with gastric but not with colon cancer, our results may provide a basis for a decision on additive, prophylactic (intraperitoneal) therapy in gastric but not colon cancer.

Immunocytology improves prognostic impact of peritoneal tumour cell detection compared to conventional cytology in gastric cancer

AIMS

Studies on the value of peritoneal tumour cell dissemination for prognosis in gastric cancer using various methods to detect tumour cells have produced conflicting conclusions. We studied the incidence and prognostic relevance of microscopic intraperitoneal tumour cell dissemination in gastric cancer, comparing conventional and immunocytological detection.

METHODS

Peritoneal wash-outs of 111 consecutive gastric patients without overt peritoneal carcinomatosis, including 75 curatively resected patients, were studied. Sixty patients with benign disorders served as controls. 100 ml of warm NaCl 0.9% was instilled intraoperatively and 20 ml was reaspirated. The specimens were stained peri-operatively with H&E. In the last 47 patients (30 of whom were curatively resected) additional immunostaining with the HEA-125 antibody was performed. The results of cytology were correlated with the TNM categories and with post-operative follow-up.

RESULTS

Of the patients, 42.3% and 48.9% were positive when conventional and immunocytological staining were employed, respectively. Conventional cytology was significantly associated with the pT and M categories. Immunocytology was significantly associated with the pT, pN and M caterogies. In four of 30 curatively resected patients (13.3%), the results of conventional and immunocytology were different. Three patients with positive immunocytology but negative conventional cytology died during follow-up (median follow-up 45.3 months), whereas one patient with positive conventional but negative immunocytology is still alive. In an univariate analysis 4 years post-surgery, positive immunocytology was significantly associated with an unfavourable prognosis in patients with curatively resected gastric cancer. While only 28.6% (six of 21) of the patients with negative immunocytology had died, this proportion increased to 77.8% (seven of nine) with positive immunocytology (P=0.018). The mean survival of negative vs positive patients amounted to 1205+/-91 vs 772+/-147 days (P=0.007). In contrast, in conventional cytology we found no significantly different survival time between negative and positive patients.

CONCLUSIONS

Immunocytology seems to be superior to conventional cytology and should be preferred.