Malignant ascites. Clinical and experimental observations

How valuable is ascitic cytology in the detection and management of malignancy?

INTRODUCTION

Ascitic cytology is often requested in the early stages of ascitic assessment. A review of this practice in a major English teaching hospital is presented.

METHOD

Patients were retrospectively identified using the histopathology and patient administration system between January 1999 and May 2001.

RESULTS

Of 276 samples sent for assessment 35 cases were found to be negative when on further review an intra-abdominal malignancy was present. The malignancy was diagnosed using a radiological modality. The sensitivity of ascitic cytology was found to be 60% with 100% specificity. A delay of up to five days could be incurred awaiting the cytology results before further radiological examinations were undertaken.

CONCLUSION

Too much hope is placed on ascitic cytology to provide the diagnosis at the expense of other investigations. It is recommended that the initial assessment should concentrate on history, examination, and basic tests on ascitic fluid to assess the serum-ascites albumin gradient. Ovarian malignancy is the only tumour type yielding a significant rate of detection from cytology with some prognostic impact. Results should not be awaited before abdominal ultrasound is undertaken. This more directed practice would help reduce unnecessary workload for the pathologist and has resource implications.

The current and future management of malignant ascites

Malignant ascites occurs in association with a variety of neoplasms. It is a frequent cause of morbidity and presents significant problems for which there are no clear management guidelines. In this article we discuss various modalities which are available including diuretic therapy, paracentesis, peritoneovenous shunts and intraperitoneal chemotherapy. There are no randomized trials of diuretic drugs to assess their efficacy in malignant ascites. Phase II data suggest that they are effective in approximately one-third of patients with malignancy, and their efficacy may be determined by plasma renin/aldosterone concentrations. Paracentesis provides relief in up to 90% of patients; because of varying reports of hypovolaemia, some advocate simultaneous intravenous fluid infusion. Permanent percutaneous drains may prevent the need for repeated paracentesis, although there is potential for infection. A peritoneovenous shunt also prevents the need for repeated paracenteses, whilst maintaining normal serum albumin concentrations. Blockage occurs in 25% of shunts, which are contraindicated in the presence of heavily bloodstained ascites because of the risk of occlusion. The preclinical and clinical experience with anti-angiogenic agents such as the matrix metalloproteinase inhibitors and the VEGF antagonists suggests that these agents may have a role in the treatment of malignant ascites.

Ascites as a predictor of ovarian malignancy

OBJECTIVE

To determine the utility of ascites as a predictor of ovarian malignancy and define its relationship with the histologic type of ovarian tumor (benign, borderline, or malignant) and stage of disease.

METHODS

This retrospective cohort study analyzed the clinical and pathological finding of 125 patients from two institutions treated for a pelvic mass. Preoperative data to include: physical examination, imaging studies (USD, CT, or MRI), and operative reports were reviewed for evidence of ascites. This was correlated with final pathologic findings and stage of disease. Collected data were summarized with descriptive statistics. Further statistical analysis was performed using Pearson's chi(2), cross tabulation, and the Median Test. Data were analyzed with SPSS 6.1 for Windows.

RESULTS

One-hundred twenty-five patients were evaluable for this study. The ovarian pathologic findings were as follows: 57 benign (45%), 12 borderline (10%), and 56 malignant (45%). Fifty-three patients (42%) had frank ascites at laparotomy. Seventy-two patients (58%) had no ascites. All patients with ascites diagnosed preoperatively (n = 41) on physical examination or imaging studies were confirmed intraoperatively. Absence of ascites was correctly diagnosed preoperatively in 72/84 patients (86%). Of the 57 benign tumors, only 5 patients (9%) had small amounts of peritoneal effusion. Of the 12 borderline tumors, 7 patients (58%) had ascites. Of the 56 malignant tumors, 41 (73%) had ascites. Using presence or absence of ascites on clinical assessment as the predictor variable and benign or malignant (borderline and invasive histopathology) tumors as the outcome variable, the positive predictive value (PPV) of ascites to detect ovarian malignancy was 95% and the negative predictive value (NPV) was 64%. When borderline tumors were excluded, the PPV and NPV of ascites to detect malignant invasive tumors were 95 and 73%, respectively. Furthermore, a progressive relationship between stage of ovarian malignancy and percentage of cases with ascites was identified. Ovarian malignancies in the early stages (I and II) produced ascites only in 17% of the cases. In advanced stages (III and IV), 89% produced ascites. In addition, for stage I and II disease, all patients possessed <0.5 liters of ascites at surgery, whereas the majority of patients (66%) with stage III and IV disease had >0.5 liters.

CONCLUSIONS

Our findings indicate the presence of ascites on preoperative physical examination or imaging study is highly predictive of ovarian malignancy in women with a pelvic mass. The absence of ascites may not always predict benign disease since nearly half of borderline tumors and 83% of early stage malignant ovarian tumors do not produce ascites. A progressive relationship between stage of malignancy and incidence as well as volume of ascites was also observed.

Tumor autocrine motility factor induces hyperpermeability of endothelial and mesothelial cells leading to accumulation of ascites fluid

Accumulation of ascites fluid often observed in some solid tumors is one of the most devastating conditions of a patient's difficulty in responding to treatment, and to a decrease in the quality of life. Various factors are thought to be associated with the formation of cancer-induced fluid accumulation and hyperpermeability of a blood vessel is thought to go with this process. Here, we report a new factor that is involved in this process, e.g., autocrine motility factor (AMF). AMF is a tumor-related cytokine which stimulates the tumor cell locomotion and migration and promotes tumor cell invasion during metastasis. AMF secretion and its receptor (AMFR) expression in tumor cells are closely correlated with disease aggravation of convalescence. The response of endothelial or mesothelial cellular morphological alternation to AMF leads to motile enhancement and vascular permeability. Tumor AMF induces gaps in an endothelial or mesothelial monolayer by stimulating a cellular movement, and accelerates the ascites accumulation. And treatment experiment with anti-AMF antibody succeeded in the reduction of the ascites accumulation, which renders AMF to the target molecule. It is suggested that AMF is one of the significant factors which relates to various pathological malignancies induced by tumor mass, and understanding of its function could benefit prognosis and treatment.

EUS in the detection of ascites and EUS-guided paracentesis

BACKGROUND

The utility of EUS was evaluated for detection of ascites and EUS-guided FNA of ascites in patients undergoing EUS for diagnosis and staging of GI malignancies.

METHODS

A series (from March 1994 to October 1997) of 571 consecutive patients who underwent upper EUS for various indications was retrospectively reviewed. Follow-up clinical information was obtained from referring physicians, subsequent CT, and telephone interviews.

RESULTS

Eighty-five patients (15% of series) were found to have ascites by EUS. Six did not have CT before EUS. Pre-EUS CT identified ascites in only 14 (18%) of the 79 patients who had pre-EUS CT. Of the patients in whom CT was negative for abdominal fluid (n = 65) and who had clinical follow-up, 13 of 58 (22%) subsequently had ascites develop that were detected by CT or physical examination. Overall, 31 of the 85 patients underwent EUS-guided FNA paracentesis; the mean volume obtained was 7.9 mL (range 1-40 mL). In 5 patients, malignant ascites was diagnosed by EUS-guided FNA; in these patients surgery was avoided.

CONCLUSIONS

EUS is more sensitive than CT in detecting small amounts of ascites. A significant number (22%) of patients who had ascites by EUS subsequently had ascites develop that was detectable by CT or physical examination. EUS-guided paracentesis appears to be safe and effective and can identify malignant ascites.

Metastatic pattern of CC531 colon carcinoma cells in the abdominal cavity: an experimental model of peritoneal carcinomatosis in rats

BACKGROUND

Peritoneal spread of tumour cells is a major source of morbidity and mortality in patients with colorectal cancer. In order to develop strategies to prevent intraperitoneal dissemination and to treat peritoneal carcinomatosis, the spread of tumour cells in the peritoneal cavity was studied.

METHODS

Two million CC531 colon carcinoma cells were administered intraperitoneally in five groups of eight rats. The rats were killed after 1, 2, 4 and 8 hours and 3, 7, 14 and 21 days. After inspection of the abdominal cavity, samples of blood and ascites were taken. Liver, spleen, omentum, mesentery, diaphragm, parathymic lymph nodes and lungs were removed for histology and immunohistochemistry.

RESULTS

No abnormalities were seen in the abdominal cavity until day 3. Subsequently the peritoneum and omentum became thickened and after 21 days all rats had haemorrhagic ascites and peritoneal carcinomatosis. The abdominal fluid contained tumour cells at all stages. The number of tumour cells decreased in the first 8 hours, and increased thereafter. At microscopy the peritoneum was completely covered by tumour cells after 3 days. Tumour cells concentrated in the milky spots (MS) of the omentum within 4 hours. The size of the MS increased as a result of an increase in number of tumour cells and macrophages. After 7--21 days the MS were completely replaced by tumour cells and new MS were formed. In the diaphragm tumour cells invaded the lymphatic lacunae after 8 h, and obliterated these after 3--7 days. Also invasion of the muscle fibres was seen after 3 days. Microscopically no tumour cells were found in blood, liver, spleen, parathymic nodes and lung.

CONCLUSION

After intraperitoneal administration of CC531 colon carcinoma cells, tumour cells spread throughout the abdominal cavity, and concentrate in the milky spots of the greater omentum, the paracolic gutters, the subhepatic and subphrenic spaces and in the lymphatic lacunae of the diaphragm.

Peritoneovenous shunting for nongynecologic malignant ascites

BACKGROUND

The development of malignant ascites has been associated with a poor prognosis. Previous reports have documented high morbidity rates associated with placement of palliative peritoneovenous shunts (PVS). Most study series have included gynecologic malignancies in their analysis, and wide variations in survival time have been reported. Reported data from nongynecologic malignancies and identification of preoperative factors associated with improved outcome were the concerns of the current study, which attempted to identify patients with malignant ascites who might have benefitted from PVS.

METHODS

A retrospective chart review was performed and data including age, gender, weight, preoperative laboratory values, cytology on peritoneal fluid aspirates, and complications within 30 days of the operative procedure were obtained and recorded. Discharge date and follow-up status were obtained for all patients. Statistical analysis was done for categorical values by comparing survival times from date of procedure with follow-up times using the log rank test. Significance for numeric values was determined with Cox regression analysis. Multivariate analysis using Cox regression was performed for those values found to be significant on univariate analysis.

RESULTS

Fifty- five patients who had undergone PVS from 1980-1996 for ascites on the Gastric and Mixed Tumor service at the Memorial Sloan-Kettering Cancer Center were identified. Two patients with benign disease and two patients with ovarian malignancies were excluded. The remaining 51 patients underwent placement of 53 PVSs for palliation. Median survival time for the entire group was 52 days. Univariate analysis identified preoperative blood urea nitrogen (BUN), creatinine (Cr), BUN to Cr ratio, and diagnosis as significant factors. Preoperative BUN emerged as an independent predictor of survival by multivariate analysis, and those patients who had a BUN value of < = 17 demonstrated a survival advantage over those with a BUN of > 17. The assessable palliation factors were hospital discharge (80% of patients) and weight loss after shunting (68% of patients lost > 1 kg). Ninety-six percent of patients (24 of 25) with a preoperative BUN of < or = 17 were discharged.

CONCLUSIONS

The development of nongynecologic malignant ascites is an end stage event for most patients. The placement of PVS for those patients with nongastrointestinal tumor etiologies, a BUN of < 17, a Cr of < or = 1.1, and a BUN to Cr ratio of < 19 yielded the best results. In the current study, palliation was difficult to assess accurately, although most patients were discharged or lost > 1kg of weight after shunting.

Diagnostic investigations in cancer pain

Defining the specific cause of pain in patients with cancer often has substantial therapeutic and prognostic implications. This process often requires the use of specific diagnostic investigations. Here we critically review the diagnostic investigations used in the evaluation of common pain problems in patients with cancer. Familiarity with this information facilitates the development of efficient and rational diagnostic strategies.

Value of ascitic fluid cholesterol and serum-ascites albumin gradient in differentiating cirrhotic and malignancy related ascites

In a perspective study, the ascitic fluid and serum concentration of total cholesterol, total proteins and albumin in a group of 45 patients was studied. Patients with nonmalignant or cirrhotic ascites were compared with patients having malignancy related ascites and it was proved that the ascitic fluid cholesterol and the serum ascites albumin gradient helped to differentiate cirrhotic from malignant ascites. These two parameters showed a remarkable relationship to the presence/absence of malignancy. Non malignant ascites patients had ascitic fluid cholesterol values of 19.41±8.33 mg/dl, as against the malignancy related ascites patients, who showed levels of 95.87±1.24 mg/dl. Similarly, the serum-ascites albumin gradient levels were 2.89±0.65 in non malignant ascites patients, while the malignancy related ascites cases had 0.86±0.50. The discrimination values for cholesterol were taken as 45 mg/dl while that for serum ascites gradient was taken as 1.1. Levels of serum cholesterol, total protein and albumin were not significantly altered.

A phase II trial of triamcinolone hexacetanide for symptomatic recurrent malignant ascites

Ascites is a common complication of advanced cancer and frequently requires paracentesis to reduce symptoms of pain, anorexia, and dyspnea. For many patients repeat paracenteses are required at short intervals. We prospectively studied 15 patients with recurrent ascites of malignancy to determine if intraperitoneal triamcinolone hexacetonide, a slowly metabolized corticosteroid, produced objective and symptomatic responses. After biochemical, radiological, and symptom assessment and the establishment of the interval between paracenteses, patients underwent large-volume paracentesis followed by intraperitoneal triamcinolone hexacetonide 10 mg/kg. Patients were followed after treatment for assessment of symptoms and physical signs of ascites. Repeat paracentesis was performed when symptomatic ascites recurred. Symptomatic ascites recurred in 13 of 15 patients, but the interval between paracenteses was extended from 9.5 +/- 1.6 days to 17.5 days (P = 0.0086). Symptom questionnaire scores assessing well-being, nausea, abdominal pain, dyspnea, appetite, appearance, and change in abdominal size on a scale from 0 to 6 averaged 3.2 +/- 0.3 at entry and 2.5 +/- 0.2 at the 2-week assessment (P = 0.026). Self-assessed symptoms, feeling of well-being, abdominal distention, and physical appearance improved significantly. The mean serum cortisol decreased from baseline, suggesting that some systemic corticosteroid absorption occurred. Thirteen of 15 patients have died, with a median survival of 42 days. Potential adverse effects included 1 episode each of transient abdominal pain, bacterial peritonitis, and localized herpes zoster infection. In patients with ascites of malignancy, intraperitoneal triamcinolone hexacetonide appears to postpone the requirement for repeat paracentesis and improve symptoms of malignant ascites.

Markedly elevated levels of vascular endothelial growth factor in malignant ascites

BACKGROUND

Vascular endothelial growth factor (VEGF) is a potent angiogenic factor that also has the ability to increase vascular permeability. Malignant ascites has significant morbidity, but the mechanism of its development is unknown. Because of the permeability-inducing properties of VEGF, we hypothesized that malignant ascites formation is associated with high levels of VEGF. The purpose of our study was to determine the role of VEGF in malignant ascites formation.

METHODS

Ascites from 25 patients with gastric (n = 6), colon (n = 7), or ovarian (n = 12) cancers was collected by paracentesis or surgery. VEGF protein levels were determined by enzyme-linked immunosorbent assay. The effect of ascites on endothelial cell permeability was assessed by evaluating propidium iodide uptake by human umbilical vein endothelial cells (HUVECs) exposed to ascites. Neutralizing antibodies to VEGF added to ascites were used to determine the causal effect of VEGF in permeability induction.

RESULTS

VEGF protein levels were markedly increased in malignant ascites compared with levels in nonmalignant cirrhotic ascites (controls). VEGF protein levels in ovarian, gastric, and colon cancer ascites were found to be increased 45, 23, and 12 times, respectively, compared with levels in cirrhotic ascites. Malignant ascites from patients with colon and gastric cancer caused an increase in permeability in HUVECs in all cases. Neutralizing VEGF activity in colon cancer ascites decreased in-vitro HUVEC permeability in three of four cases.

CONCLUSIONS

VEGF protein levels are markedly elevated in malignant ascites. VEGF may play a role in malignant ascites formation by increasing endothelial cell permeability.

A survey of practice in management of malignant ascites

The purpose of this study was to determine physicians' attitudes toward and preferences for palliative management of malignant ascites. A random sample of eighty physicians practicing in Canada was selected from the memberships of the Canadian Association of Medical Oncologists, the Canadian Association of Gastroenterology, the Canadian Society of Palliative Care Physicians, and the Society of Gynecologic Oncologists of Canada. Physicians were questioned on their use of different modalities in management of malignant ascites, and preferences based on attitudes toward efficacy of various treatments. Eighty surveys were mailed, with a second mailing, followed by telephone contact. The response rate was 76% (59/78), with two potential respondents deemed ineligible. Among the 44 physicians who treat malignant ascites, paracentesis is employed by 43 (98%), and felt to be effective by 39 (89%). Diuretics are used by 61% (27/44), although fewer feel diuretics are effective management (20/44, 45%). Peritoneovenous shunts, dietary measures, and other modalities are used less frequently than either paracentesis or diuretics. The most commonly used means of managing malignant ascites is paracentesis, which is also felt to be the most effective by the group surveyed. After paracentesis, diuretics and peritoneovenous shunting are used most frequently, but there is no apparent consensus as to their effectiveness. Managing malignant ascites remains problematic, and we propose further study of management strategies to clarify the role of various treatments.

Temporary drainage of symptomatic malignant ascites by a catheter inserted under computerized tomography

The development of malignant ascites is an unfavorable prognostic sign in patients with advanced cancer. Interventions may be justified when discomfort and overall compromise in well-being are due to diaphragmatic spinting and abdominal compression of viscera. A patient with symptomatic ascites was admitted to hospital for temporary drainage using a catheter inserted under computerized tomography. Over 12 liters of fluids were removed in 3 days, without complications. A minimal ascitic leakage occurred after removing the cannula. Dyspnea and gastrointestinal symptoms improved and the patient died with good symptom control 15 days later. This approach should be considered in advanced cancer patients with symptomatic ascites that is not responsive to diuretics.

Colorectal carcinoma and the relationship of peritoneal cytology

BACKGROUND

This study was designed to investigate the frequency of the association between colorectal cancer and peritoneal cytology as well as the impact of surgical resection on conversion of cytology from benign to malignant cells being present. Furthermore, increasingly frequent reports of port site recurrences with laparoscopic colectomy for limited stage colon carcinoma prompted us to evaluate the incidence of tumor cell spillage with traditional "open" colonic surgery.

METHODS

Fifty random patients undergoing surgery for colorectal carcinoma were prospectively evaluated with peritoneal washings prior to and following colon resection.

RESULTS

Five patients (10%) were found to have malignant cytology, with no patients converting from negative to positive cytology. All five positive cytologies were associated with stage IV disease and poorly differentiated colon cancer.

CONCLUSION

Intraoperative peritoneal cancer dissemination could not be demonstrated by cytologic washings of the abdominal cavity before and after colorectal resection utilizing standard cytomorphological criteria.

Malignant ascites: a 2-year review from a teaching hospital

In this retrospective review of 164 consecutive patients with malignant ascites it has been shown that ovarian ascites accounts for 28% of the total and is associated with a significantly improved survival compared with other groups (P<0.001). Non-ovarian ascites is associated with a very poor prognosis and many patients in this group are unsuitable for aggressive treatment. In 49% of patients, ascites will be the presenting feature requiring further investigation to ascertain the primary tumour. Thorough investigation of female patients should be performed in order to identify all patients with an ovarian primary so that appropriate chemotherapy can be given. However, thorough investigation in male patients is not justifiable.

Tumor necrosis factor effects on ascites formation in an experimental tumor model

In humans, treatment of malignant ascites with bolus TNF leads to resolution of the ascites. In an experimental model NMRI nude mice were inoculated intraperitoneally with human NIH-OVCAR3 adenocarcinoma cells, resulting in production of ascites and intraperitoneal tumor growth. Ascites formation and tumor growth after IP injection of recombinant human TNF was determined. Depending on the treatment schedule, a dual effect of TNF on the development of ascites was seen. Doses of TNF (1-10 micrograms/g) given once per week completely prevented ascites production, whereas the same doses of TNF given on a daily schedule induced enhanced ascites formation in an inverse TNF dose relationship. The area of tumor cell-covered peritoneal lining corresponded to these findings, indicating a correlation of tumor mass with ascites production. In an attempt to prevent renewal of ascites after drainage, neither inhibition nor enhancement in ascites production was seen when TNF was given five times per week. However, doses of 10 micrograms/g of TNF once per week led to almost complete inhibition of ascites reappearance. Histological examination of animals that received repeated TNF treatment demonstrated chronic peritonitis with strong stromal proliferation, angiogenesis, and increased adhesion of tumor cells to the peritoneum.

Malignant ascites

Investigation and treatment of malignant ascites are often in the hands of the general surgeon and can be difficult. This article considers the aetiology and pathophysiology of malignant ascites and explores the best form of management. Established treatment modalities and new therapeutic options are reviewed and a new management regimen based on a knowledge of the tumour of origin is proposed, which aims to balance potential benefit against morbidity.

New strategies for the management of malignant ascites

Intractable malignant ascites accounts for 6% of all hospice admissions. The onset of malignant ascites indicates a poor prognosis, hence minimal supportive therapy is indicated. This paper examines the method of control for malignant ascites presently available to patients, examines their limitations and proposes new strategies for managing intractable malignant ascites. Ascites is discussed in terms of its pathology--that is, as a form of lymphoedema. With this in mind treatment is proposed based upon principles incorporated into lymphoedema management. Nurses have taken a dominant role in the care of patients with lymphoedema and there appears no reason why ascites management cannot become the remit of nurses offering appropriate, but predominantly palliative therapy.

The fibrinolytic system in human ascites

BACKGROUND

We recently reported that the contact and kallikrein-kinin systems are activated in malignancy-related ascites. We have now studied the fibrinolytic system in ascites and plasma from patients with gastrointestinal cancer(n = 14) and non-malignant liver disease (n = 18).

METHODS AND RESULTS

Enzyme immunoassays (EIAs) showed that urokinase and tissue plasminogen activators (uPA, tPA) and PA inhibitors (PAI-1, PAI-2) were present in ascites from both patient groups and that tPA was the predominant PA. uPA, tPA, and PAI-1, were detected in plasma from patients and controls. These EIA findings were supported by zymography studies. Functional assays showed considerable generation of plasmin-like activity and low plasminogen and antiplasmin values in malignancy-related ascites. The plasmin/antiplasmin and tPA/PAI-1 ratios were particularly high in malignancy-related ascites as compared with non-malignant ascites. Plasma from the liver disease patients showed a higher tPA/PAI-1 ratio and, thus a higher potential for plasminogen activation than plasma from cancer patients and controls. Patient plasma showed low values of plasmin-like activity, antiplasmin, and plasminogen.

CONCLUSION

Our findings show that the fibrinolytic system is activated in malignancy-related ascites.

Free fatty acid analysis in ascitic fluid improves diagnosis in malignant abdominal tumors

The fasting concentration of free fatty acids (FFA) in the ascitic fluid was determined in 14 patients with malignant ascites and in 19 patients with liver cirrhosis. In malignant ascites FFA levels were increased more than three times when compared with the levels in cirrhotic ascites (5.241 +/- 0.493 vs. 1.558 +/- 0.170 mumol/ml; P < 0.0001). Palmitic acid was the most representative saturated FFA (which together accounted for 2.499 +/- 0.323 vs. 0.833 +/- 0.064 mumol/ml; P < 0.0001), while unsaturated FFA (2.741 +/- 0.298 vs. 0.725 +/- 0.111 mumol/ml; P < 0.001) were represented, in decreasing order, by oleic, linoleic and arachidonic acids. The ratio of unsaturated to saturated FFA was higher in neoplastic patients (1.35 +/- 0.29 vs. 0.826 +/- 0.065 P < 0.05). Albumin concentration in ascitic fluid of neoplastic patients was 22.44 +/- 1.35 g/l, while that of cirrhotic patients was 8.19 +/- 0.32 g/l, P < 0.0001. A close relationship (R2 = 95.14%) between albumin concentration in ascitic fluid and levels of total FFA was found. These data support the hypothesis that the elevation of FFA in ascitic fluid allows discrimination between malignant and non-malignant ascites.

Clinical value of tumour markers and serum-ascites albumin gradient in the diagnosis of malignancy-related ascites

To determine the clinical value of tumour markers in the diagnosis of malignancy-related ascites (not including hepatocellular carcinoma), serum and ascitic fluid levels of carcinoembryonic antigen, cancer antigen 125, carbohydrate antigen 19-9, tissue polypeptide antigen and serum-ascites albumin gradient were determined in 66 patients with cirrhotic ascites, 28 patients with hepatocellular carcinoma and ascites, and 29 patients with malignancy-related ascites. Three tumour markers and serum-ascites albumin gradient showed significant difference between patients with malignancy-related ascites and those without: serum carcinoembryonic antigen (26.4 +/- 31.5 vs 4.8 +/- 4.6 ng/mL, P < 0.01), ascitic fluid carcinoembryonic antigen (118.4 +/- 196.5 vs 2.0 +/- 1.4 ng/mL, P < 0.01), ascitic fluid carbohydrate antigen 19-9 (12,933 +/- 25,496 vs 23 +/- 67 U/mL, P < 0.01) and serum-ascites albumin gradient (1.1 +/- 0.4 vs 2.0 +/- 0.4 g/dL, P < 0.01). At the best cut-off levels chosen from near 95% of the data in those without malignancy-related ascites, the sensitivity, specificity and accuracy to diagnose malignancy-related ascites were, respectively, 65.5%, 93.6%, 87.0% using serum carcinoembryonic antigen > or = 10 ng/mL; 69.0%, 94.7%, 88.6% using ascitic fluid carcinoembryonic antigen > or = 5 ng/mL; 65.5%, 93.6%, 87.0% using ascitic fluid carbohydrate antigen 19-9 > or = 50 U/mL; 62.1%, 98.9%, 90.2% using serum-ascites albumin gradient < 1.1 g/dL. Although serum-ascites albumin gradient offered the best diagnostic accuracy and specificity, its sensitivity was not good enough. Our study indicates that serum-ascites albumin gradient and tumour markers are not sensitive parameters in the diagnosis of malignancy-related ascites.

Differential diagnosis of human ascites: inhibitors of the contact system and total proteins

To assess their accuracies as markers for malignancy, we assayed alpha 2-macroglobulin, C1-inhibitor, alpha 1-protease inhibitor, and total proteins in ascites and plasma from patients with gastrointestinal cancer (n = 15) and non-malignant liver disease (n = 13), using functional and immunologic assays. For all inhibitors and total proteins determined in ascites, the values in the cancer group were significantly higher than the corresponding values in the group with non-malignant liver disease. The diagnostic accuracy for differentiating malignancy-related from non-malignant ascites was 93% for a alpha 1-protease inhibitor value > or = 50% of the pool plasma value and 90% for alpha 2-macroglobulin > or = 16%, C1-inhibitor > or = 40% (all functional assays), and total proteins > or = 20 g/l (biuret). In conclusion, functional assays for alpha 2-macroglobulin, C1-inhibitor, and alpha 1-protease inhibitor and determination of total proteins in ascites appeared to be very informative tests for the differential diagnosis of ascites. The test for alpha 1-protease inhibitor gave higher specificity (92% versus 77%) and likelihood ratio for a positive test (12 versus 4) compared with the other tests.

Malignant ascites. A comparison of peritoneovenous shunting and nonoperative management

BACKGROUND

Effective palliation of malignant ascites remains a difficult management problem.

METHODS

Eighty-five patients with malignant ascites were studied. Forty-two patients had peritoneovenous shunts (PVS) inserted (16 LeVeen, 17 single-valve Denver, 9 double-valve Denver).

RESULTS

Shunt patency was not related to the type of shunt, type of cancer, or any characteristic of the ascitic fluid. Ascites was controlled in 64% of patients with shunts and serum albumin levels were preserved. Survival and quality of life were not significantly different in comparison with those of patients treated by abdominal paracentesis.

CONCLUSIONS

PVS allowed many patients to be treated successfully outside the hospital and are indicated in carefully selected cases.

Pathophysiology of elevated ascites fluid cholesterol in malignant ascites. Increased ascites to serum relation of proteins and lipoproteins in patients with peritoneal carcinomatosis as compared to patients with cirrhosis of the liver

The existence of marked elevations of ascitic fluid cholesterol has been observed in patients with peritoneal carcinomatosis compared to patients with cirrhosis and has been found useful in differential diagnosis. This finding could be caused by an enhanced movement of plasma lipoproteins into the peritoneal cavity. To test this hypothesis we determined the fasting concentrations of total, high density lipoprotein (HDL)- and low density lipoprotein (LDL)-cholesterol, apolipoprotein-A1 (apo-A1) and apolipoprotein-B (apo-B) in serum and ascites of 17 patients with cirrhosis and 16 patients with peritoneal carcinomatosis. The movement of proteins from plasma to ascites was calculated from the ascites/serum concentration ratios of six different sized proteins with a molecular mass ranging from 54 kDa to 971 kDa. Mean values (mg/dl) for total cholesterol (92.6 vs. 21.0), HDL-cholesterol (15.6 vs. 1.8), LDL-cholesterol (63.4 vs. 16.1), apo-A1 (50.2 vs. 13.6) and apo-B (41.2 vs. 12.9) in ascites were significantly higher in peritoneal carcinomatosis than in cirrhosis. These differences could only partially be explained by the higher serum concentrations of these parameters in peritoneal carcinomatosis, but were mainly due to a lower selectivity for the movement of plasma proteins and lipoproteins into ascites (mean ascites/serum (A/S) ratio: 0.30-0.77) in peritoneal carcinomatosis as compared to cirrhosis (mean ascites/serum ratio: 0.11-0.21). In both groups about 85% of the total cholesterol in serum and ascites consisted of HDL- and LDL-cholesterol. These findings support the hypothesis that elevations in ascitic cholesterol in peritoneal carcinomatosis compared to cirrhosis are mainly caused by the increased movement of plasma HDL and LDL into the peritoneal cavity.

Ascitic fluid analysis for the differentiation of malignancy-related and nonmalignant ascites. Proposal of a diagnostic sequence

The authors tried to differentiate malignancy-related from nonmalignant ascites with a sequence of sensitive followed by specific ascitic-fluid parameters. There were four results of this study. First, of nine parameters investigated in a first series of 48 patients, 28 with nonmalignant and 20 with malignancy-related ascites, ascitic-fluid cholesterol and fibronectin yielded the best negative predictive value of 92% each. Carcinoembryonic antigen (CEA) and cytologic examination both showed a positive predictive value of 100%. Second, combining cytologic examination (sensitivity, 70%) and CEA determination (sensitivity, 45%) increased the sensitivity to 80%. Third, cytologic findings were negative in all ascitic-fluid samples with a cholesterol concentration below the cutoff value of 45 mg/100 ml. Fourth, based on the results of the first series of 48 patients, the diagnostic sequence with cholesterol as a sensitive parameter, followed by the combination of cytologic examination and CEA determination as specific parameters, was tested in a second series of 71 patients, 37 with nonmalignant and 34 with malignancy-related ascites. Again cytologic examination was negative in all samples with cholesterol levels below 45 mg/100 ml. In the total of 119 patients, this diagnostic sequence did not identify 9% of patients with malignancy-related ascites, and 82% of samples classified as malignancy related by cholesterol levels above 45 mg/100 ml were confirmed by positive cytologic examination and/or CEA level above 2.5 ng/ml. Thus, a diagnostic sequence with ascitic-fluid cholesterol determination, followed by cytologic examination and CEA determination, in samples with cholesterol levels above 45 mg/100 ml should permit a cost-efficient routine differentiation of malignancy-related from nonmalignant ascites.

Implications of peritoneal cytology for staging of early pancreatic cancer

Cytologic examination of peritoneal washings was performed in 40 patients with pancreatic ductal adenocarcinoma (35 head, 5 body) whose tumors had been selected as potentially resectable by computed tomographic (CT) findings. Saline (100 mL) was instilled and aspirated at laparoscopy in 27 patients and at laparotomy in 13. Malignant cells were found in the peritoneal washings in 12 of 40 patients (30%): 29% in cancers of the pancreatic head versus 40% in the body; 33% at laparoscopy versus 23% at laparotomy; and in 4 of 8 patients with ascites versus 8 of 32 without ascites. The cytology was positive in 6 of 8 patients (75%) who had a prior percutaneous needle biopsy versus 6 of 32 (19%) of those who did not (p less than 0.01). Liver metastases were found in six patients, all with negative cytology. One of 10 pancreatic head cancers with positive cytology was resectable versus 13 of 25 with negative cytology (p less than 0.05). Survival was significantly longer in patients with negative cytology. We conclude that (1) pancreatic cancer sheds malignant cells into the peritoneum early and commonly; (2) laparoscopic lavage is an effective means of cytologic study; (3) ascites is not a precondition for cytologic study, nor does its presence necessarily imply carcinomatosis; (4) intraperitoneal spread of cancer cells may be promoted by tumor biopsy; (5) cytologic findings provide an additional index of resectability; and (6) cytologic findings appear to correlate with duration of survival. This study shows that even "localized" pancreatic cancer is often not contained and suggests caution with biopsy of potentially curable lesions.

Ascitic fluid concentrations of fibronectin and cholesterol: comparison of differential diagnostic value with the conventional protein determination

Ascitic fluid concentrations of fibronectin, cholesterol and protein were determined in 95 patients: 38 with cirrhosis of the liver, 10 with miscellaneous nonmalignant diseases, 43 with peritoneal carcinomatosis and 4 with liver metastases or hepatocellular carcinoma. Fibronectin, cholesterol and protein at discrimination values of 7.5 mg/100 ml, 45 mg/100 ml and 3.0 g/100 ml, respectively, separated patients with peritoneal carcinomatosis from patients with cirrhosis with an efficiency of 94%, 90% and 85%, respectively. Thus, ascitic fluid determinations of fibronectin and cholesterol offer good discrimination of cirrhotic ascites from ascites related to peritoneal carcinomatosis, superior to the conventional protein determination. However, the failure of all parameters to distinguish ascites caused by miscellaneous nonmalignant diseases from malignancy-related ascites underscores the importance of highly specific methods to confirm a suspected diagnosis of malignancy-related ascites.

Malignant ascites: review of the literature, and an update on monoclonal antibody-targeted therapy

Malignant ascites presents a difficult clinical problem, causing discomfort and distress to patients in the later stages of disease. Repeated attempts at palliation are often unsuccessful. In this article, conventional forms of therapy for malignant ascites are reviewed and their limitations outlined. Furthermore, we present data on a new form of therapy: antibody guided irradiation. Pilot studies have produced encouraging results in the management of malignant serous effusions, and further randomised studies are currently in progress.

Diagnostic accuracy of sialic acid in the diagnosis of malignant ascites

The authors evaluated the diagnostic accuracy of sialic acid and its lipid-bound fraction in ascites and compared these tests with others (fibronectin, cholesterol) recently claimed as valuable in the differential diagnosis of ascites. Fibronectin yielded the best diagnostic accuracy (85%) with no false-positive and 37% of false-negative (10/27). The authors also found higher concentration of sialic acid in malignant ascites than in nonmalignant ascites (P less than 0.001) and, taking 300 mg/l as the cutoff value, the false-positive rate was 10% (four of 40), the false-negative rate 30% (eight of 27), and the overall diagnostic accuracy 82%, comparable to that of the fibronectin. The authors conclude that both fibronectin and sialic acid determinations in ascites may be regarded as accurate markers of neoplastic involvement of the peritoneum, although no test is useful in the ascites with hepatocellular carcinoma and cirrhosis of the liver.

Peritoneal carcinomatosis in nongynecologic malignancy. A prospective study of prognostic factors

Regional recurrence of malignant tumors in the peritoneal cavity usually signifies a poor prognosis for the host and often results in gastrointestinal complications requiring surgical intervention. One hundred patients with nongynecological malignancies found with peritoneal carcinomatosis were followed prospectively. The most common primary tumors were colorectal (N = 45) and pancreatic (N = 20) carcinoma. When associated with pancreatic carcinoma, 65% of patients had liver metastases and 60% had ascites. The presence of ascites was associated with poor survival, with no patient surviving past 30 days. Ascites was also a sign of poor prognosis in patients with colorectal carcinoma. Among possible prognostic factors in colorectal carcinoma patients, only disease-free interval, presence of lung metastases, and ascites showed statistically significant correlations with survival. Peritoneal carcinomatosis in sarcoma (N = 7) and breast cancer (N = 6) patients had median survival of 12 and 7 months, respectively. Surgical intervention for gastrointestinal complications in peritoneal carcinomatosis can provide significant palliation, with a few exceptions such as in patients with pancreatic or gastric carcinoma, ascites, and poor performance status.

Ascitic fluid analysis in malignancy-related ascites

A prospective study identified 45 patients with malignancy-related ascites among 448 ascites patients (10% of the total). Patients were categorized into five subgroups based on the pathophysiology of ascites formation. Each subgroup had a distinctive ascitic fluid analysis. Patients with peritoneal carcinomatosis but without massive liver metastases (53.3% of the patients with malignancy-related ascites) had a uniformly positive ascitic fluid cytology, high ascitic fluid protein concentration and low serum-ascites albumin gradient. Patients with massive liver metastases and no other cause for ascites formation (13.3% of the series) had a negative cytology, low ascitic fluid protein concentration, high serum-ascites albumin gradient and markedly elevated serum alkaline phosphatase. Those with peritoneal carcinomatosis and massive liver metastases (13.3% of the series) had a nearly uniformly positive ascitic fluid cytology, variable protein concentration, high serum-ascites albumin gradient and markedly elevated serum alkaline phosphatase. Chylous ascites (6.7%) was characterized by a milky appearance, negative cytology and an elevated ascitic fluid triglyceride concentration. Patients with hepatocellular carcinoma superimposed on cirrhosis (13.3%) had negative ascitic fluid cytology, low ascitic fluid protein concentration, high serum-ascites albumin gradient and elevated serum and ascitic fluid alpha-fetoprotein concentration. Two-thirds of patients with malignancy-related ascites had peritoneal carcinomatosis; 96.7% of patients with peritoneal carcinomatosis had positive ascitic fluid cytology. Ascitic fluid analysis is helpful in identifying and distinguishing the subgroups of malignancy-related ascites.

Mechanisms of malignant ascites production

The accumulation of malignant ascites is determined primarily by the obstruction of diaphragmatic lymphatics with tumor inhibiting the outflow of peritoneal fluid. An abnormal increase in peritoneal fluid production has been shown to contribute to ascites formation by a marked neovascularization of the parietal peritoneum. Cell-free malignant ascitic fluid obtained from rats with intra-abdominal Walker 256 carcinoma when infused into the peritoneal cavities of normal animals causes an increase in edema formation and an increase in the permeability of protein from normal omental vessels. Protamine sulfate, a known inhibitor of angiogenesis when infused into the peritoneal cavity along with cell free malignant ascitic fluid, significantly reduces the leak of protein from the intravascular space when compared to ascites alone. Persistent permeability changes continue to exist even after the inhibition of vessel proliferation. These results indicate that angiogenesis is responsible for a major portion of the increase in permeability caused by malignant ascitic fluids. Other tumor-induced factors may be present which alter vascular permeability by other mechanisms which remain to be elucidated.