Extracapsular tumor spread and the risk of local, axillary and supraclavicular recurrence in node-positive, premenopausal patients with breast cancer

BACKGROUND

Extracapsular tumor spread (ECS) has been identified as a possible risk factor for breast cancer recurrence, but controversy exists regarding its role in decision making for regional radiotherapy. This study evaluates ECS as a predictor of local, axillary, and supraclavicular recurrence.

PATIENTS AND METHODS

International Breast Cancer Study Group Trial VI accrued 1475 eligible pre- and perimenopausal women with node-positive breast cancer who were randomly assigned to receive three to nine courses of classical combination chemotherapy with cyclophosphamide, methotrexate, and fluorouracil. ECS status was determined retrospectively in 933 patients based on review of pathology reports. Cumulative incidence and hazard ratios (HRs) were estimated using methods for competing risks analysis. Adjustment factors included treatment group and baseline patient and tumor characteristics. The median follow-up was 14 years.

RESULTS

In univariable analysis, ECS was significantly associated with supraclavicular recurrence (HR = 1.96; 95% confidence interval 1.23-3.13; P = 0.005). HRs for local and axillary recurrence were 1.38 (P = 0.06) and 1.81 (P = 0.11), respectively. Following adjustment for number of lymph node metastases and other baseline prognostic factors, ECS was not significantly associated with any of the three recurrence types studied.

CONCLUSIONS

Our results indicate that the decision for additional regional radiotherapy should not be based solely on the presence of ECS.

Survival and safety of exemestane versus tamoxifen after 2-3 years' tamoxifen treatment (Intergroup Exemestane Study): a randomised controlled trial

BACKGROUND

Early improvements in disease-free survival have been noted when an aromatase inhibitor is given either instead of or sequentially after tamoxifen in postmenopausal women with oestrogen-receptor-positive early breast cancer. However, little information exists on the long-term effects of aromatase inhibitors after treatment, and whether these early improvements lead to real gains in survival.

METHODS

4724 postmenopausal patients with unilateral invasive, oestrogen-receptor-positive or oestrogen-receptor-unknown breast cancer who were disease-free on 2-3 years of tamoxifen, were randomly assigned to switch to exemestane (n=2352) or to continue tamoxifen (n=2372) for the remainder of a 5-year endocrine treatment period. The primary endpoint was disease-free survival; overall survival was a secondary endpoint. Efficacy analyses were intention-to-treat. This study is registered as an International Standard Randomised Controlled Trial, number ISRCTN11883920.

RESULTS

After a median follow-up of 55.7 months (range 0-89.7), 809 events contributing to the analysis of disease-free survival had been reported (354 exemestane, 455 tamoxifen); unadjusted hazard ratio 0.76 (95% CI 0.66-0.88, p=0.0001) in favour of exemestane, absolute benefit 3.3% (95% CI 1.6-4.9) by end of treatment (ie, 2.5 years after randomisation). 222 deaths occurred in the exemestane group compared with 261 deaths in the tamoxifen group; unadjusted hazard ratio 0.85 (95% CI 0.71-1.02, p=0.08), 0.83 (0.69-1.00, p=0.05) when 122 patients with oestrogen-receptor-negative disease were excluded.

CONCLUSIONS

Our results suggest that early improvements in disease-free survival noted in patients who switch to exemestane after 2-3 years on tamoxifen persist after treatment, and translate into a modest improvement in overall survival.

Identifying breast cancer patients at risk for Central Nervous System (CNS) metastases in trials of the International Breast Cancer Study Group (IBCSG)

BACKGROUND

We sought to determine whether a high-risk group could be defined among patients with operable breast cancer in whom a search of occult central nervous system (CNS) metastases was justified.

PATIENTS AND METHODS

We evaluated data from 9524 women with early breast cancer (42% node-negative) who were randomized in International Breast Cancer Study Group clinical trials between 1978 and 1999, and treated without anthracyclines, taxanes, or trastuzumab. We identified patients whose site of first event was CNS and those who had a CNS event at any time.

RESULTS

Median follow-up was 13 years. The 10-year incidence (10-yr) of CNS relapse was 5.2% (1.3% as first recurrence). Factors predictive of CNS as first recurrence included: node-positive disease (10-yr = 2.2% for > 3 N+), estrogen receptor-negative (2.3%), tumor size > 2 cm (1.7%), tumor grade 3 (2.0%), < 35 years old (2.2%), HER2-positive (2.7%), and estrogen receptor-negative and node-positive (2.6%). The risk of subsequent CNS recurrence was elevated in patients experiencing lung metastases (10-yr = 16.4%).

CONCLUSION

Based on this large cohort we were able to define risk factors for CNS metastases, but could not define a group at sufficient risk to justify routine screening for occult CNS metastases.

Body mass index as a prognostic feature in operable breast cancer: the International Breast Cancer Study Group experience

BACKGROUND

Current information on the prognostic importance of body mass index (BMI) for patients with early breast cancer is based on a variety of equivocal reports. Few have data on BMI in relationship to systemic treatment.

PATIENTS AND METHODS

Patients (6792) were randomized to International Breast Cancer Study Group trials from 1978 to 1993, studying chemotherapy and endocrine therapy. BMI was evaluated with eight other factors: menopausal status, nodal status, estrogen receptor status, progesterone receptor status, tumor size, vessel invasion, tumor grade and treatment. BMI was categorized as normal (< or =24.9), intermediate (25.0-29.9) or obese (> or =30.0).

RESULTS

Patients with normal BMI had significantly longer overall survival (OS) and disease-free survival (DFS) than patients with intermediate or obese BMI in pairwise comparisons adjusted for other factors. Subset analyses showed the same effect in pre- and perimenopausal patients and in those receiving chemotherapy alone. When assessed globally and adjusted for other factors, BMI significantly influenced OS (P = 0.03) but not DFS (P = 0.12).

CONCLUSIONS

BMI is an independent prognostic factor for OS in patients with breast cancer, especially among pre-/perimenopausal patients treated with chemotherapy without endocrine therapy.

Risk factors for locoregional recurrence among breast cancer patients: results from International Breast Cancer Study Group Trials I through VII

PURPOSE

To explore prognostic factors for locoregional failures (LRF) among women treated for invasive breast cancer within clinical trials of adjuvant therapies.

PATIENTS AND METHODS

The study population consisted of 5,352 women who were treated with a modified radical mastectomy and enrolled in one of seven International Breast Cancer Study Group randomized trials. A total of 1,275 women with node-negative disease received either no adjuvant therapy or a single cycle of perioperative chemotherapy, and 4,077 women with node-positive disease received adjuvant chemotherapy of at least 3 months' duration and/or tamoxifen. Median follow-up is 12 to 15.5 years.

RESULTS

In women with node-negative disease, factors associated with increased risk of LRF were vascular invasion (VI) and tumor size greater than 2 cm for premenopausal and VI for postmenopausal patients. Of the 1,275 patients, 345 (27%) met criteria for the highest risk groups, and the 10-year cumulative incidences of LRF with or without distant metastases were 16% for premenopausal and 19% for postmenopausal women. For the node-positive cohort, number of nodes and tumor grade were factors for both menopausal groups, with additional prediction provided by VI for premenopausal and tumor size for postmenopausal patients. Of the 4,077 patients, 815 (20%) met criteria for the highest risk groups, and 10-year cumulative incidences were 35% for premenopausal and 34% for postmenopausal women.

CONCLUSION

LRFs are a significant problem after mastectomy alone even for some patients with node-negative breast cancer, as well as after mastectomy and adjuvant treatment for some subgroups of patients with node-positive disease. In addition to number of positive lymph nodes, predictors of LRF include tumor-related factors, such as vascular invasion, higher grade, and larger size.

Duration of adjuvant chemotherapy for breast cancer: a joint analysis of two randomised trials investigating three versus six courses of CMF

Cyclophosphamide, methotrexate and fluorouracil adjuvant combination chemotherapy for breast cancer is currently used for the duration of six monthly courses. We performed a joint analysis of two studies on the duration of adjuvant cyclophosphamide, methotrexate and fluorouracil in patients with node-positive breast cancer to investigate whether three courses of cyclophosphamide, methotrexate and fluorouracil might suffice. The International Breast Cancer Study Group Trial VI randomly assigned 735 pre- and perimenopausal patients to receive 'classical' cyclophosphamide, methotrexate and fluorouracil for three consecutive cycles, or the same chemotherapy for six consecutive cycles. The German Breast Cancer Study Group randomised 289 patients to receive either three or six cycles of i.v. cyclophosphamide, methotrexate and fluorouracil day 1, 8. Treatment effects were estimated using Cox regression analysis stratified by clinical trial without further adjustment for covariates. The 5-year disease-free survival per cents (+/-s.e.) were 54+/-2% for three cycles and 55+/-2% for six cycles (n=1024; risk ratio (risk ratio: CMFx3/CMFx6), 1.00; 95% confidence interval, 0.85 to 1.18; P=0.99). Use of three rather than six cycles was demonstrated to be adequate in both studies for patients at least 40-years-old with oestrogen-receptor-positive tumours (n=594; risk ratio, 0.86; 95% confidence interval, 0.68 to 1.08; P=0.19). In fact, results slightly favoured three cycles over six for this subgroup, and the 95% confidence interval excluded an adverse effect of more than 2% with respect to absolute 5-year survival. In contrast, three cycles appeared to be possibly inferior to six cycles for women less than 40-years-old (n=190; risk ratio, 1.25; 95% confidence interval, 0.87 to 1.80; P=0.22) and for women with oestrogen-receptor-negative tumours (n=302; risk ratio, 1.15; 95% confidence interval, 0.85 to 1.57; P=0.37). Thus, three initial cycles of adjuvant cyclophosphamide, methotrexate and fluorouracil chemotherapy were as effective as six cycles for older patients (40-years-old) with oestrogen-receptor-positive tumours, while six cycles of adjuvant cyclophosphamide, methotrexate and fluorouracil might still be required for other cohorts. Because endocrine therapy with tamoxifen and GnRH analogues is now available for younger women with oestrogen-receptor-positive tumours, the need for six cycles of cyclophosphamide, methotrexate and fluorouracil is unclear and requires further investigation.

Influence of endocrine-related factors on response to perioperative chemotherapy for patients with node-negative breast cancer

PURPOSE

We investigated tumor- and patient-related features that might influence the response to perioperative chemotherapy (PeCT) compared with no adjuvant therapy for patients with node-negative breast cancer.

PATIENTS AND METHODS

A total of 1,275 patients were randomized to either no adjuvant treatment (427 patients) or PeCT (848 patients). The following variables thought to have prognostic significance were evaluated: grade, tumor size, estrogen (ER) and progesterone receptor (PgR) content (absent; low, 1 to 9 fmol/mg cytosol protein; or positive, > or = 10 fmol/mg cytosol protein), c-erbB-2 overexpression, menopausal status, and age. Cox proportional hazards regression models were used to assess the relative influence of these factors to predict the effect of PeCT on disease-free survival (DFS). Median follow-up was 13.5 years.

RESULTS

The 10-year DFS percentage for 692 premenopausal patients did not significantly differ between the PeCT and no-adjuvant-treatment groups: 61% and 59%, respectively (relative risk [RR], 0.95; 95% confidence interval [CI], 0.75 to 1.20; P = .70). No predictive factors were identified. For 583 postmenopausal patients, 10-year DFS percentages for the groups were 63% and 58%, respectively (RR, 0.75; 95% CI, 0.58 to 0.93; P = .03). The absence of expression of ER, PgR, or both ER and PgR was the most important factor predicting improved outcome with PeCT among postmenopausal patients. The 10-year DFS percentages were 85% and 53% for the steroid hormone receptor-absent cohort of treated and untreated patients, respectively (RR, 0.18; 95% CI, 0.06 to 0.49; P = .0009).

CONCLUSION

The role of PeCT should be explored for patients whose primary tumors do not express steroid hormone receptors, because it is likely that early initiation of treatment is exclusively relevant for such patients.

The influence of zymosan and indomethacin on liver and kidney tumor growth. An experimental study in rats

Zymosan, a non-specific macrophage-stimulating agent, modifies favourably tumour growth in the liver but has minor effect on renal tumours. The mechanism accounting for variation is still to be clarified. The effect of zymosan on liver cancer may be mediated by the macrophage-monocyte system. Kupffer cells are in vitro cytotoxic against colon cancer cell lines. The kidney is sparse in macrophage elements. The prostaglandin synthesis inhibitor, indomethacin, inhibits tumor growth. In Wistar-FU rats inoculated in the liver and the kidney with an adenocarcinoma cell suspension, pretreatment with zymosan (3 mg x 100 g[-1]) significantly reduced both tumour take and liver volume. This effect was attenuated by concomitant administration of indomethacin (0.2 mg x 100 g[-1]). After 2 weeks there was still reduced liver tumour volume. No significant effects on tumour take or growth were observed when the cells were inoculated into the kidney. There was no significant effect of zymosan on an hepatoma in Lister-Hooded rats. Pretreatment with indomethacin had no effect on tumor take or initial growth.

Influence of zymosan (a non-specific macrophage stimulator) and of indomethacin on liver tumours--an experimental study in rats

Zymosan--a non-specific macrophage-stimulating agent--reduces tumour take in the liver. The mechanism for this effect is not clear, but it may be mediated via the Kupffer cells and prostaglandins. On the other hand, the Prostaglandin-synthesis inhibitor, indomethacin, inhibits tumour growth. Pretreatment with zymosan (3 mg 100 g-1) for 3 days of two different strains of rats, inoculated in the liver with a hepatoma or an adenocarcinoma cell suspension respectively, reduced tumour take and also initial tumour growth. The effect on tumour take and initial growth was inhibited by concomitant administration of indomethacin (0.2 mg 100 g-1). When zymosan was administered after tumour cell inoculation the growth rate of the hepatoma was retarded, but this effect was not abrogated by indomethacin. Pretreatment with indomethacin had no significant effect on tumour take or initial growth. When given after the tumour was established in the liver, indomethacin reduced the growth rate of the hepatoma, but not of the adenocarcinoma. These results suggest that there are different mechanisms for the effects of zymosan on tumour take and on growth of an established tumour. In immunoincompetent nude mice the effect on the hepatoma was similar to the effect in the rat. In vitro both tumours were insensitive to zymosan and indomethacin. This study confirms that pretreatment with a non-specific macrophage stimulator (zymosan) diminishes tumour take and growth in the liver, that the effect of zymosan on tumour take in the liver is abrogated by indomethacin and that the zymosan effect on tumour take in the liver is at least partly mediated by the Kupffer cells and prostaglandins.

Hepatocyte and Kupffer cell function after liver transplantation in the rat--in vivo evaluation with dynamic scintigraphy

In vivo physiological measurements of hepatocyte and Kupffer cell function after liver transplantation are desirable. Orthotopic liver transplantation was performed in 54 rats. Hepatocyte and Kupffer cell function were measured with dynamic liver scintigraphy. Hepatic clearance of 99mTc-Nanocoll (%/min), an albumin colloid phagocytosed by the Kupffer cells, was used to evaluate Kupffer cell function. Hepatic clearance of 99mTc-IODIDA (%/min), an imino-diacetic-acid taken up and secreted by the hepatocytes, was used to evaluate the hepatocyte function. Hepatic clearance in control rats was 27 +/- 2%/min for Nanocoll and 30 +/- 3 %/min for IODIDA. After syngenic liver transplantation, without rejection, there was a rise in Nanocoll clearance (34 +/- 2 %/min p < 0.01) after 3 weeks, but no change in IODIDA clearance (32 +/- 3 %/min N.S.). After syngenic liver transplantation with preservation time prolonged to 16 h, there were no changes in IODIDA or Nanocoll clearance 1 day after transplantation. Both IODIDA (11 +/- 2 %/min) and Nanocoll clearance (22 +/- 2 %/min) were decreased (p < 0.001) during rejection after allogenic transplantation. An in vivo method of measuring the hepatocyte and Kupffer cell function in the transplanted liver is described. Kupffer cell function was increased after syngenic liver transplantation. Kupffer cell and hepatocyte function were decreased during rejection. Dynamic liver scintigraphy seems a suitable procedure for examining liver injury after liver transplantation in the experimental setting.

Influence of liver transplantation and cyclosporin on bile secretion--an experimental study in the rat

Bile secretion is reduced after liver transplantation. It has been suggested that this is due either to the effect of cyclosporin or to the damage to the liver graft during preservation and reperfusion. The aim of this study was to explore the influence of cyclosporin as well as of liver transplantation on bile secretion. Bile flow was studied in an experimental model in the rat. In syngeneic liver-transplanted animals, the bile flow was increased compared to the bile flow in the control group (1.29 +/- 0.09 ml/h vs 0.66 +/- 0.03 ml/h; P < 0.01), mainly due to an increased bile acid-independent flow (0.76 ml/h vs 0.50 ml/h; P < 0.01). The findings in the liver-transplanted rats contrasted with those in a group of nontransplanted animals treated with cyclosporin. Cyclosporin treatment resulted in a reduced bile acid-independent fraction (0.37 ml/h vs 0.50 ml/h, P < 0.05) of the bile flow, although no biochemical signs of hepatotoxicity were present. This reduction in the bile acid-independent fraction could, however, not be demonstrated when cyclosporin was given to a group of liver-transplanted rats, although a reduced total bile flow was recorded in the 1st hour measurements. In contrast to previous studies, we found that the cyclosporin vehicle (Cremophor EL), when administered chronically, induced a higher bile flow than that in the control rats. This effect was not seen in the transplanted rats. Our findings in this experimental rat model indicate that cyclosporin will influence and reduce bile secretion and bile acid secretion even if no other signs of liver dysfunction are present. On the other hand, the preservation and reperfusion in this model resulted in an increased bile flow, while bile acid secretion remained constant.

Hepatic artery occlusion and energy charge in rat liver tumour

Hepatic artery ligation (HAL) is a model for inducing a vascular attack on liver tumours which causes a reduction in tumour growth. To determine in an experimental rat liver adenocarcinoma the duration and magnitude of changes in adenonucleotide concentration and energy charge (EC) after HAL, analyses of energy-rich nucleotides were performed at 1, 2, 24 and 168 hours after HAL or a SHAM procedure. There was a significant decrease of the ATP content and energy charge in the tumour one hour after HAL. Two hours after HAL this difference had decreased and with longer observation it was not detectable. Twenty-four hours of starvation did not significantly alter the effects of HAL on the tumour. HAL gives rise to a transient energy depletion of the tumour which is not completely compensated for by glycolysis after 1 hour, but is restored after 2 hours.

Treatment of liver metastases from colorectal cancer with hepatic artery occlusion, intraportal 5-fluorouracil infusion, and oral allopurinol. A randomized clinical trial

BACKGROUND

Regional therapy for colorectal liver metastases aimed at prolonging survival has not been tested fully in a randomized trial with untreated control subjects. This study explored the efficacy of temporary hepatic artery occlusion followed by intraportal infusion of 5-fluorouracil (5-FU) and oral allopurinol as biochemical modulators in prolonging the survival of patients with nonresectable liver metastases and no extrahepatic cancer.

METHODS

Eighty-four patients were considered for randomization, of whom 24 were excluded at laparotomy because of extrahepatic cancer (n = 17) or resectable lesions (n = 5). In two patients, no cancer was identified in the liver. Thirty-two patients were allocated to receive treatment, and 28 were allocated to receive no regional or systemic treatment. Six patients were excluded after randomization because of major protocol violations.

RESULTS

The median survival time for patients was 17 months (range, 0-66), and for control subjects, the median was 8 months (range, 0-31). Log rank analysis demonstrated a significant survival benefit for treatment versus no treatment (P = 0.0039). (In two patients, early death was due to toxicity from the wrong dose of 5-FU and the wrong route of administration, respectively; the mean and median survival were reduced by 1 month).

CONCLUSION

This study identified a treatment modality that prolongs survival in patients with nonresectable liver metastases and no extrahepatic metastases from colorectal cancer, suggesting that control subjects receiving no therapy may not be necessary in future randomized trials.

Biochemical modulation of intraperitoneal fluorouracil by allopurinol-the effect on an experimental adenocarcinoma in the liver

In a rat liver tumour system with a nitrosoguanidine-induced carcinoma and in an in vitro system with the same tumour, the effect of allopurinol on the toxicity and antitumour effect of 5-fluorouracil (5-FU) was explored. Two doses of 5-FU, 30 and 60 mg/kg b.w. intraperitoneally (i.p.), were tested with a large dose of allopurinol subcutaneously (s.c.( (300 mg) in rats. The drugs were given for three consecutive days. The lethal toxicity of 60 mg 5-FU i.p. could not be counteracted by allopurinol. Allopurinol and 30 mg 5-FU reduced the tumour growth rate more than 5-FU alone. The spleen was smaller, as a sign of increased toxicity, without allopurinol. The concentration of allopurinol and its metabolites in the general circulation was high. In vitro, there was no additive or specific effect of allopurinol. These results indicate some in vivo metabolic modulation of 5-FU efficacy by allopurinol if 5-FU is administered intraperitoneally and allopurinol systemically.

Isolated hyperthermic liver perfusion with chemotherapy for liver malignancy

In an open study of unresectable liver tumours, isolated regional perfusion with hyperthermia and cytotoxic drugs has been tested in 29 patients. Four patients had primary hepatocellular cancer, 10 patients had metastases from malignant melanoma, remaining from breast cancer, colorectal cancer, midgut carcinoids and miscellaneous primaries. At laparotomy the proper hepatic artery and portal vein were canulated and connected to a pump oxygenator. The inferior vena cava was canulated with a triple lumen catheter (Perfufix) allowing for porto-caval shunting, drainage of lower body and renal veins to the heart and separate drainage of liver veins to the pump oxygenator. Liver perfusion was performed with a mean flow of 900 ml per min. Melphalan and cis-platinum 0.5 mg/kg body-weight were added to the perfusate for 1 h after liver temperature reached 40 degrees C. Four patients died within 30 days of perfusion due to multiple organ failure. These patients had more than 50% of liver volume occupied by cancer. All surviving patients developed reversible hepato- and renal toxicity. Partial tumour regression was registered in 20% of the patients. Five patients have survived more than three years. Hyperthermic liver perfusion is feasible but in patients with massive liver tumour, there is a significant risk of developing multiple organ failure.

The effects of tumour necrosis factor alpha on the vascular bed and blood flow in an experimental rat hepatoma

The influence of TNF alpha on tumour growth rate has been attributed to its effects on the vascular bed and blood flow. The aim of our study was to investigate the effects of pharmacological doses of TNF alpha on the tumour vascular bed and to quantify blood flow in an experimental hepatoma during a more extended period after TNF-alpha exposure than hitherto reported. In Lister rats, a syngeneic rat hepatoma was implanted on the dorsum of the right hind foot. TNF alpha was given i.v. The injection was repeated after 24 hr. Tumour blood flow was estimated before and 1, 24, and 96 hr after TNF-alpha administration with the 133Xe-washout technique. The passage of microspheres through the tumour vascular bed (non-entrapment), as a measure of vascular occlusion, was estimated 4 and 96 hr after TNF-alpha administration. Tumour growth rate was measured. The tumours were subjected to histological examination and the sensitivity to TNF alpha in vitro was tested. A reduction of tumour blood flow was observed in TNF-alpha-treated groups. Tumour growth rate was equally increased after 96 hr in both the TNF-alpha groups as compared with controls. There was no significant change in non-entrapment for the TNF-alpha-treated rats as compared with controls. Histology revealed extensive necrosis and thrombosis in tumours. TNF alpha had no effect on the viability of the cloned hepatoma cell line in vitro.

[Malignant melanoma of the skin in Denmark--epidemiology, diagnosis and treatment]

About 700 new cases of malignant melanoma of the skin are registered annually in Denmark. The incidence is increasing rapidly and the number of new cases increases by more than 5% per annum. The most important phenotypical risk factors are the number of acquired pigmented naevi and exposure to sunlight is the most important risk factor in the external environment so that severe sunburn in children and intermittent intense exposure to sunlight increase the risk of melanoma. The thickness of the tumour at the time of the diagnosis is the most important prognostic factor. The prognosis deteriorates with increasing thickness. Treatment is primarily surgical. In cases of inoperable local melanoma and regional recurrences, irradiation may be administered. Chemotherapy and/or immunotherapy are of experimental character. In the light of the rapidly increasing incidence, it is important that knowledge of risk factors for development of the disease and the clinical characteristics of early melanoma is spread to not only the medical profession but also to the general public.

The influence of hepatic artery ligation and of vasopressin on liver tumour blood flow in rats

The blood flow in an experimental adenocarcinoma in the rat liver was determined with the 133Xe-washout technique before and after hepatic artery ligation (HAL). There was an initial reduction of the washout of 50%. This was further reduced after 1 day by 50%, which was maintained for 7 days. Seven days after HAL or sham procedures the 133Xe-washout was of similar magnitude in the liver tumours, although after the sham procedure the tumours were larger (3.4 g vs. 1.5 g). The estimated tumour blood flow was then approximately 0.04 ml x min-1 x g-1. The influence on normal liver parenchyma of HAL was a reduction at 30 minutes, which was maintained for 7 days. Postacton--a synthetic vasopressin--did not influence the 133Xe-washout in normal liver parenchyma in non-tumour, as well as in tumour-bearing animals. There was no influence of Postacton on the 133Xe-washout in the liver tumours. Thirty minutes after HAL Postacton gave a reduction of blood flow in normal liver parenchyma of tumour-bearing animals, which is thus only from the portal vein. In tumours Postacton did not significantly reduce the tumour blood flow immediately after HAL.

Kupffer cell and hepatocyte function in rat transplanted liver

The liver consists essentially of two compartments, parenchymal cells (PC) and non parenchymal cells (NPC) i. e. Kupffer cells, endothelial cells, fat storing cells and pit cells. PC remain after transplantation but NPC are eventually exchanged with host cells. Dynamic liver scintigraphy with albumin colloid, extracted by NPC, and IODIDA, extracted by PC, were tested to evaluate function as determined by clearance rates in these two cellular compartments. Experimental liver transplantation was performed in 15 syngeneic rats. Following transplantation, we performed dynamic liver scintigraphy with 0.5 ml 5 MBq 99mTc-Nanocoll and 0.5 ml 20 MBq 99mTc-IODIDA, 10 s per frame, 30 min for each examination. Percentage clearance rate, per minute was calculated from uptake curves over the liver. Uptake curves were nearly exponential and clearance rates could be estimated from a logarithmic plot of uptake versus time. The clearance rate was 25 +/- 4% per min (mean +/- SD) for NPC and 32 +/- 15% per min for PC in controls. After liver transplantation it was 31 +/- 7% per min for NPC and 30 +/- 15% per min for PC. Dynamic liver scintigraphy with 99mTc-Nanocoll and 99mTc-IODIDA alloweds a separate assessment of the function of PC and NPC after experimental liver transplantation in rats.

Cytotoxicity of liver macrophages against liver tumours. Influence of betamethasone, indomethacin and allopurinol

Macrophage activation with zymosan has an inhibitory effect on tumour take and initial tumour growth in the rat liver. 91 rats with syngeneic transplanted hepatoma in the liver were treated with zymosan (46) or saline (45). Betamethasone (glucocorticoid), indomethacin (prostaglandin synthesis inhibitor), allopurinol (oxygen radical scavenger) or saline were administered concomitantly. Tumour take, tumour growth and relative spleen weight were used as in vivo parameters of liver macrophages cytotoxicity and general macrophage activation. Zymosan inhibition of tumour take was counteracted by betamethasone, indomethacin and allopurinol. Betamethasone increased the growth rate of the non-zymosan treated tumours during seven days. Indomethacin decreased the growth rate of the tumours in non-zymosan treated rats up to 14 days. Allopurinol significantly blocked the zymosan inhibition of tumour take and tumour growth after 7 and 14 days. Allopurinol blocked zymosan induced increased relative spleen weight. It is proposed that the liver macrophage cytotoxicity induced by zymosan is in part mediated via production of oxygen radicals.

Macrophage function and surgery. A clinical review with special reference to phagocytosis

Present knowledge of macrophage phagocytosis in the context of surgical trauma is reviewed. The historical and morphologic background of the reticuloendothelial system and the mononuclear phagocyte system is surveyed. The physiology of the phagocytic process and methods of measurement are summarized and the influence on phagocytosis of shock, sepsis, cancer, parenteral nutrition and surgical procedures such as liver resection and splenectomy is discussed. Conclusions are that multiple factors may depress macrophage phagocytosis during surgery and that, in order to maintain immune defence balance, traumatic manipulation of tissue and abdominal organs must be minimized.

Comparison of seven iodine-labelled monoclonal antibodies in nude mice with human colon carcinoma xenografts

The biokinetics of seven 131I-labelled monoclonal antibodies (MAbs), directed against human colon carcinoma and one 125I-labelled unspecific MAb have been examined. The study in nude mice, carrying human colon carcinoma, was intended to be a step in the selection of the most suitable antibody for clinical scintigraphy. The biological half-life in blood was found to be between 1.3 and 7.4 days for the different MAbs. Chromatography of plasma samples showed that the radioiodine was mainly bound to IgG-sized molecules. The (normal tissue)/blood ratios were similar for all the MAbs. The tumour/blood ratio was 0.41 for the unspecific MAb and 0.49-1.1 for the specific MAbs, and the tumour/muscle ratio was between 3.2 and 6.8 for the specific MAbs 6 days after injection. For one MAb tumour/blood and tumour/muscle ratios were 3.9 and 9.8 respectively 9 days after injection. Localization indices were at their highest 2.6 6 days after injection. For at least two of the monoclonal antibodies the tumour/blood and tumour/muscle ratios found are high enough to justify clinical trials regarding their usefulness for scintigraphy of colon cancer in man.

Vascular clearance by the reticuloendothelial system--measurements using two different-sized albumin colloids

Normal and reticuloendothelial system (RES) stimulated rats were examined with dynamic liver RES scintigraphy using a computerized gamma camera. 99Tcm-labelled albumin colloid, albures (radius 250 nm) or nanocoll (radius 25 nm), or both were used as test substances to study the kinetics of vascular clearance after RES stimulation. Registrations were made of 30 s per frame for 5 min and 300 s per frame for 15 min or 25 min and a region of interest (ROI) was indicated over the liver. Whole body and liver RES clearance rate constants (k) were calculated from the liver uptake vs time curve. Liver parenchyma blood flow was estimated with 133Xe washout technique. The blood clearance rate constant of albures in non-activated rats was twice that for nanocoll (1.08 +/- 0.05 vs 0.49 +/- 0.02 10(-2)s-1). There was no mutual interaction between the two colloids, implying that they may be eliminated from the blood-stream by slightly different processes. In zymosan-stimulated animals, nanocoll given in a single injection showed a significantly increased k-value. Neither the albures clearance rate constant nor the nanocoll/albures k-value ratio revealed RES macrophage activation. By contrast the nanocoll/albures ratio, calculated for the liver, rose significantly. The final colloid uptake in the liver revealed RES macrophage activation. No changes in liver parenchyma blood flow per g tissue could be registered after administration of zymosan. The nanocoll and albures colloid particles did not impair the normal liver parenchyma blood flow.(ABSTRACT TRUNCATED AT 250 WORDS)

Tumour adjacent macrophage function in experimental tumours

This study describes in vivo methodology for evaluating whole body and Tumour Adjacent Macrophage (TAM) phagocytic function in tumour-bearing rats. 29 Wistar rats were inoculated with 1 x 5 mm cylinders of syngeneic NGW-adenocarcinoma im in the right hind leg. 10 rats were given iv zymosan (3mg/100 g b.w.) for systemic activation of macrophages, 9 rats were given intratumour injection of zymosan (3mg/100g b.w.) for local activation and 10 rats were untreated controls. 10 days after tumour inoculation whole body phagocytic rate was estimated with dynamic liver RES scintigraphy. Tumour and blood radionuclide activity was measured. Dynamic liver RES scintigraphy measures whole body macrophage phagocytic rate (k) of iv 99Tcm Nanocoll albumin test colloid. TAM phagocytic rate is calculated from the final uptake in tumor/injected dose x k. Systemic macrophage activation caused a significant increase in liver and spleen weight and whole body phagocytic rate (0.65 +/- 0.02 versus 0.56 +/- 0.03% s-1). The TAM phagocytic rate was significantly elevated in tumors treated by local macrophage activation (0.003 +/- 0.00 versus 0.001 +/- 0.00% s-1). This study suggests that the TAM phagocytic rate is a sensitive indication of local macrophage activity.

Kinetics of radioiodinated monoclonal antibodies in the rat. Influence of tumour growth and reticuloendothelial system host modulation

This experimental study in rats examines the influence of tumour growth and RES function modulation on the kinetics of iodinated MAb IgG1 C241. The study was designed to investigate unspecific accumulation in liver and blood. C241 is raised against human colon adenocarcinoma COLO 205 and reacts with SiLea tumour-associated antigen, also known as tumour-associated antigen 19-9. In 26 rats, 2 micrograms 125I MAb C241 (lodobead labelling method) was given i.v. Blood, organ and tumour content was measured at 0.5, 24, 72 and 144 h. In 61 rats, 10 micrograms 131I MAb C241 (lodogen labelling method) was given i.v. The rats were divided into a non-tumour and a tumour-bearing group and subjected to RES function modulation with Zymosan stimulation or methyl palmitate depression. A syngeneic nitrosoguanidine-induced colonic carcinoma--mean 11 g--was growing in back subcutaneous tissue and hind leg musculature. Serum content of tumour-associated antigen was not found on IRMA testing and tumour content of SiLea ganglioside antigen was found only on lipid binding phase assay. The half-time in blood of iodinated MAb C241 was three days. In-vivo release of iodine was tested by plasma separation on a gel column. More than 90% of the iodine was in the IgG fraction. The activity distribution was almost in equilibrium after 24 h. A tumour/blood activity concentration ratio of 0.5 and liver/blood ratio of 0.3 remained at 72 h and 144 h. Radionuclide accumulation was equally low in the macrophage-rich liver and the kidneys. Tumour-bearing animals had significantly lower blood content (0.37 versus 0.99% g-1) and liver content (0.09 versus 0.31% g-1) at 144 h than non-tumour-bearing rats. The whole body content at 144 h was also lower (24% versus 35% of administered activity) (p = 0.10). Modulation of RES function had no significant influence on the whole body, blood or liver content of 131I MAb C241 activity in non-tumour-bearing animals. In tumour-bearing animals, RES stimulation with Zymosan increased the whole body, liver and blood content of 131I activity. The two tested methods of iodination gave similar results.

RES-macrophage stimulation and liver tumour growth in rats; evaluation with dynamic liver RES scintigraphy

Dynamic liver RES scintigraphy with Nanocoll (99Tcm albumin colloid - 50 nm diameter) assessing RES-macrophage phagocytic function was performed in 40 control, 73 RES-stimulated non-tumour-bearing and 59 tumour-bearing Wistar/FU rats in vivo. Tumour-bearing rats were inoculated with 10(6) x 1.0 cells of a syngeneic nitrosoguanidine-induced colonic carcinoma in the liver. Twenty-eight of these rats had been treated one day previously with Zymosan (3 mg x 100 g-1 i v) as a RES stimulant. The clearance/uptake rate (k) of Nanocoll was calculated from dynamic liver images by the slope in the plot 1n [1 - U(t)/U] versus t where t is time and U liver uptake. k-value in control animals was 0.45 +/- 0.01.10(-2) x s-1 Zymosan injection in non-tumour-bearing rats caused stati-stically significant higher clearance/uptake rate on day 1, through 8 after treatment compared to that of controls. On day 8 k-value was 0.64 +/- 0.04. In tumour-bearing rats the uptake rate (k) was on day 8 0.66 +/- 0.03, while in RES-stimulated tumour-bearing rats it was 0.64 +/- 0.03. Survival was 22 +/- 1 days in tumour bearing rats and 37 +/- 4 days in RES stimulated tumour-bearing rats. The average tumour volume after one week was 132 +/- 24 mm3 in non-stimulated rats and 20 +/- 5 mm3 in RES stimulated rats. There was a negative correlation between uptake rate and tumour volume and a positive correlation between uptake rate and survival on day 8 in non-stimulated tumour-bearing rats. Dynamic liver RES scintigraphy with small size 99Tcm albumin colloid (Nanocoll) can be used to measure RES phagocytic function and the effect of liver tumour growth on RES.

RES function and tumour take and tumour growth in the liver and in the kidney--an experimental study in rats

This experimental study in rats examines tumour take and growth after RES modulation in an organ rich in macrophages--the liver--vs. an organ poor in macrophages--the kidney. A control group of 16 rats had 1.0 X 10(6) transplantable adenocarcinoma cells inoculated in the liver and the same number in the left kidney. They were compared with a RE-stimulated group of 16 rats treated i.v. with Zymosan (3 mg/100 g for 3 days) and a RE-depressed group of 16 rats treated with i.v. methylpalmitate (100 mg/100 g for 3 days) before tumour inoculation. Tumour size was measured on days 7 and 14. The animals were killed on day 14. Mortality was significantly higher in methylpalmitate-treated rats than in control groups. Tumour take in the kidney was not affected by RES stimulation or depression. In the liver, RES stimulation caused significantly less tumour take. Depression of RES with methylpalmitate did not increase tumour take or tumour growth in the liver, which was very high in the control group.

Phagocytosis and dynamic RES scintigraphy: an evaluation of commercial colloids in rats

Reticuloendothelial system (RES) phagocytic function or capacity can be measured by clearance studies with test substances. This study in the rat examines three commercially available 99Tcm-labelled test substances, and different methods of calculating RES capacity. Albures size 500 nm and sulphur colloid size 600 nm used for liver scintigraphic imaging and Nanocoll size 50 nm used for bone-marrow scintigraphic imaging were tested. The rats were examined under a gamma camera and the uptake by the liver, clearance from the heart and clearance from blood samples were recorded. Different amounts of substances were tested. The final uptake in different organs was recorded after the animals were sacrificed. Colloid size and stability were tested with a polycarbonate filter. (Nanocoll was found to have at least 10 times smaller colloid diameter, leading to a thousand times more particles per milligram). RES function was calculated as the uptake rate or clearance rate, k. In a logarithmic plot, the relationship between uptake or clearance and time was found to be linear between 90 and 300s and calculations of k in this interval are recommended. k-values selected from blood sample curves were 11 +/- 5 S.E.M. lower than those calculated from heart clearance curves or liver uptake curves. Increasing amounts of Nanocoll caused a decrease in uptake rate k. Albures and sulphur colloid could not be given in amounts that caused any change in k. Only Nanocoll could be given in sufficiently large amounts (above the critical dose) to challenge RES and avoid complete extraction from the circulation during first passage through RE organs. Nanocoll seems suitable for use in tests of RES function and the optimal amount was 0.03 mg per rat (0.6 X 10(12) particles).