CLINICAL STUDY
Evaluation of plasma insulin-like growth factor binding protein-2 as a marker for adrenocortical tumors
Nathalie Boulle1, Eric Baudin2, Christine Gicquel1, Armelle Logie1, Jérôme Bertherat3, Alfred Penfornis4, Xavier Bertagna3, Jean-Pierre Luton3, Martin Schlumberger2 and Yves Le Bouc1
1 Laboratoire d’Explorations Fonctionnelles Endocriniennes, Hôpital Trousseau, AP-HP and Unité INSERM U515, Hôpital Saint-Antoine 75012 Paris, France, 2Service de Médecine Nucléaire, Institut Gustave Roussy, 94805 Villejuif cedex, France, 3 Service d’Endocrinologie, Hôpital Cochin, 75014 Paris, France and 4Service d’Endocrinologie, Centre Hospitalier Universitaire de Besançon, 25030 Besancon cedex, France
(Correspondence should be addressed to N Boulle, Laboratoire d’Explorations Fonctionnelles Endocriniennes, Hôpital Trousseau, 26 Avenue Arnold Netter, 75012 Paris, France; Email: lab.endoc@trs.ap-hop-paris.fr)
Abstract
Objective: Recent studies have pointed to the role of the IGF system in the pathogenesis of adrenocortical tumors, and it was shown recently that malignant adrenocortical tumors exhibit a high insulin-like growth factor binding protein (IGFBP)-2 content. Circulating markers specific for adrenocortical carcinoma are needed and the aim of this study was to evaluate plasma IGFBP-2 as a marker for these malignant tumors.
Methods: Plasma IGFBP-2 was determined in 51 patients referred to our institutions for adrenocortical tumors. Fifteen patients were in complete remission (group 1), eight patients had preoperative localized tumors (group 2) and 28 patients had metastatic tumors (group 3). Thirty-six healthy volunteers constituted a control group.
Results: There was no significant difference in plasma IGFBP-2 concentration between healthy controls and patients with complete remission or localized tumors. In contrast, patients with metastatic disease had significantly higher IGFBP-2 plasma levels than the control group (P < 0.001). IGFBP-2 levels in patients with metastatic disease were inversely correlated with survival (R2 = 0.308; P = 0.0026). In patients with localized tumors, there was no correlation between plasma IGFBP-2 concentration and tumor size or histological features. Analysis of individual IGFBP-2 concentrations showed that five patients (17.8%) with metastatic tumors had normal IGFBP-2 levels and two patients (13.3%) in complete remission had high plasma IGFBP-2 levels. The influence of nutrition, hormone secretion and treatment on IGFBP-2 levels was examined. Nutritional status was evaluated by determining IGF-I levels and was found to be normal in 16 patients (61.5%) with high IGFBP-2 levels, suggesting that malnutrition was not responsible for the high IGFBP-2 concentrations in these patients. IGFBP-2 levels did not differ significantly according to tumor secretion or mitotane treatment. In a follow-up study, plasma IGFBP-2 concentration remained stable in patients with complete remission or stabilized disease and was a late marker of tumor progression in patients with progressive metastatic disease.
Conclusions: These results indicate that plasma IGFBP-2 is elevated in patients with malignant adrenocortical tumors and that the major factor affecting IGFBP-2 levels in these patients is tumor stage. However, plasma IGFBP-2 was less sensitive than expected for a tumor marker, which may limit its value in the diagnosis and follow-up of adrenocortical carcinoma.
European Journal of Endocrinology 144 29-36
Introduction
Adrenocortical carcinoma is a rare tumor with an approximate annual incidence of two cases per million population (1). Its prognosis is poor, with fewer than 20% patients surviving 5 years after diagnosis (2). These tumors are often diagnosed at an advanced stage, at which treatment is only palliative (3). In small localized tumors, the main problem is distinguishing unambiguously between benign and malignant tumors
as there are no absolute histologic criteria for malignancy.
Recent studies have identified various factors assoc- iated with the proliferation and transformation of adrenocortical tumor cells (1, 4). One of them, insulin- like growth factor-II (IGF-II) is strongly associated with adrenocortical malignancy. IGF-II has been shown to be involved in the proliferation of adrenocortical tumor cells in vitro, using the NCI H295R cell line derived from a human adrenocortical carcinoma (5). Furthermore,
human malignant adrenocortical tumors frequently exhibit dysregulation of the IGF system. These include an imprinting mistake of the 11p15 region in which the IGF-II gene is located, overexpression of IGF-II and its receptor, the type 1 IGF receptor, and a high content in IGF-binding protein-2 (IGFBP-2) (6-10).
These molecular markers are potential new tools for the diagnosis and prognosis of adrenocortical tumors (4). By contrast, there is no specific circulating marker available for adrenocortical carcinoma, which would help in identifying patients at high risk of malignancy before surgery. For instance, the concentration of IGF- II, which is overexpressed in malignant tumors, is not high in the plasma of patients suggesting a local role for this growth factor (7). Analysis of tumor secretions has suggested that adrenocortical carcinomas preferentially produce androgens and steroidogenic precursors (1, 11, 12). These secretory profiles may be of use in the follow-up of treated patients but they are neither specific nor sensitive markers of adrenocortical malig- nancy (2).
In vivo, the IGFs are bound with high affinity to IGF- binding proteins (IGFBPs). Six IGFBPs have been described to date, all of which locally modulate negatively or positively the effects of IGFs (13,14). We have previously shown that malignant adrenocortical tumors contain large amounts of one particular IGF- binding protein, IGFBP-2 (5, 10). The precise role of IGFBP-2 in adrenocortical tumorigenesis is presently unknown. However, similarly high levels of IGFBP-2 have been described in models of various tumors including lung carcinoma, prostate, ovarian and Wilms’ tumors, rhabdomyosarcoma and neuroblas- toma (15-20). High levels of circulating IGFBP-2 have also been demonstrated in patients with these malig- nancies (16, 21-25). In patients with prostate carcinoma and ovarian tumors, serum IGFBP-2 has been shown to correlate with specific tumor markers (PSA and CA125 respectively) (24, 26). This suggests that circulating IGFBP-2 is related to tumor cell proliferation and might therefore be of clinical use for determining prognosis and in the follow-up of patients with these tumors.
In light of these observations and because malignant adrenocortical tumors have a high IGFBP-2 protein content, we hypothesized that circulating IGFBP-2 levels would be elevated in adrenocortical carcinoma. In the present study, we assessed the value of plasma IGFBP-2 (i) as a marker of malignancy in preoperative adrenocortical tumors and (ii) in the follow-up of patients with adrenocortical carcinoma.
Patients and methods
Patients
Fifty-one patients (20 males, 31 females; mean age, 43.4 ± 14.1 years; range, 18-78 years) followed in
our institutions for adrenocortical tumors were included in this study. Tumors were defined according to histological criteria (Weiss score) and TNM classification (27). Localized tumors (stages I and II) were classified as benign (absence of all criteria for malignancy), suspect (Weiss score 1-3) or malignant (Weiss score >3) (8, 28). The characteristics of the patients are presented in Table 1. Patients were assigned to three groups according to the extent of the tumor after imaging evaluation (baseline X-rays, abdominal ultrasono- graphy, computerized tomography (CT) scans of the abdomen and the chest).
Group 1 consisted of 15 patients in complete remission as defined by World Health Organization (WHO) criteria (29). All these patients had undergone successful surgery with complete removal of the tumor before this study. Group 2 consisted of eight preopera- tive patients with localized adrenocortical tumors (stage I or II). Staging of the tumor was confirmed by subsequent surgery and histological examination. Group 3 consisted of 28 patients with metastatic disease (liver and/or lung metastases, n = 28; bone metastases, n = 3). Twenty-five of these 28 patients (89%) had previously undergone surgery. For this group, survival was calculated from the time of IGFBP-2 determination.
As shown in Table 1, 28 of the 51 patients received at least one treatment during the study including mitotane and chemotherapy (3).
Several blood samples were available for 17 patients during a follow-up study (mean follow-up: 6.7 months; range, 2-14 months) (Table 1). For five patients (patients 30, 32, 41, 42 and 46; Table 1), comparisons between plasma IGFBP-2 levels and evolution of the disease was performed at various periods of the follow-up study (partial response to treatment, stabilized disease and progressive disease). For these 17 patients, evolution of the disease was determined after complete imaging evaluation according to WHO criteria. Stable disease was defined as a reduction of less than 50% or an increase of less than 25% in the sum of the products of the perpendicular diameters of all lesions with no evidence of new lesions between two IGFBP- 2 measurements at least 4 weeks apart. A partial response to treatment was defined as a reduction of at least 50% in the sum of the products of the longest perpendicular diameters of all measurable lesions and the absence of new lesions. Progressive disease was defined as an increase greater than 25% in tumor size or the appearence of new lesions (29).
The control group consisted of 36 healthy volunteers (14 males, 22 females; mean age, 39 ± 16 years; range, 17-78 years) with no history of tumor, renal or hepatic disease, or malnutrition. There was no sig- nificant difference in age or sex between the control group and the group of patients.
| Patientª | Sex | Age | Tumor histology | Tumor weight (g) | Tumor stage at time of study | Duration of remission (months) | Hormonal pattern at time of study | Treatment at time of study | Evolution of disease" during follow-up study |
|---|---|---|---|---|---|---|---|---|---|
| Group 1 | |||||||||
| 1 | M | 76 | Benign | Complete remission | 102 | NS | No treatment | ||
| 2 | M | 61 | Benign | Complete remission | 123 | NS | No treatment | ||
| 3 | M | 33 | Benign | Complete remission | 7 | NS | No treatment | ||
| 4 | F | 31 | Suspect | Complete remission | 47.5 | NS | Mitotane | CR | |
| 5 | M | 54 | Suspect | Complete remission | 52 | NS | No treatment | CR | |
| 6 | F | 31 | Suspect | Complete remission | 40.5 | NS | Mitotane | CR | |
| 7 | F | 24 | Suspect | Complete remission | 7 | NS | Mitotane | ||
| 8 | M | 34 | Suspect | Complete remission | 4 | NS | No treatment | ||
| 9 | F | 36 | Malignant | Complete remission | 13 | NS | No treatment | CR | |
| 10 | F | 74 | Malignant | Complete remission | 81 | NS | No treatment | ||
| 11 | F | 54 | Malignant | Complete remission | 11 | NS | No treatment | CR | |
| 12 | F | 44 | Malignant | Complete remission | 5 | NS | No treatment | ||
| 13 | M | 36 | Malignant | Complete remission | 3 | NS | No treatment | ||
| 14 | F | 44 | Malignant | Complete remission | 44 | NS | Mitotane | CR | |
| 15 | F | 18 | Malignant | Complete remission | 7 | NS | Mitotane | ||
| Group 2 | |||||||||
| 16 | F | 50 | Benign | 46 | Localized | GC | No treatment | ||
| 17 | M | 33 | Benign | 13 | Localized | GC + M | No treatment | ||
| 18 | F | 55 | Benign | 10 | Localized | GC | No treatment | ||
| 19 | F | 44 | Malignant | 43 | Localized | GC | No treatment | ||
| 20 | F | 18 | Malignant | 24 | Localized | A | No treatment | ||
| 21 | M | 36 | Malignant | 164 | Localized | NS | No treatment | ||
| 22 | F | 40 | Malignant | 295 | Localized | GC + A | No treatment | ||
| 23 | F | 78 | Malignant | 150 | Localized | NS | No treatment | ||
| Group 3 | |||||||||
| 24 | F | 21 | Malignant | Metastatic disease | GC + A | Mitotane + chemotherapy | |||
| 25 | F | 32 | Malignant | Metastatic disease | NS | Mitotane | PD | ||
| 26 | F | 35 | Malignant | Metastatic disease | GC + A | Mitotane + chemotherapy | |||
| 27 | F | 40 | Malignant | Metastatic disease | GC | Mitotane | PD | ||
| 28 | F | 25 | Malignant | Metastatic disease | NS | Mitotane | |||
| 29 | M | 49 | Malignant | Metastatic disease | NS | No treatment | |||
| 30 | M | 65 | Malignant | Metastatic disease | E2 | Mitotane + chemotherapy | ST-PD | ||
| 31 | M | 43 | Malignant | Metastatic disease | NS | No treatment | PD | ||
| 32 | F | 51 | Malignant | Metastatic disease | GC | Mitotane | PR-ST-PD | ||
| 33 | M | 40 | Malignant | Metastatic disease | NS | Mitotane | |||
| 34 | F | 30 | Malignant | Metastatic disease | NS | Mitotane | |||
| 35 | M | 54 | Malignant | Metastatic disease | GC | Mitotane | |||
| 36 | M | 47 | Malignant | Metastatic disease | GC | No treatment | |||
| 37 | F | 43 | Malignant | Metastatic disease | NS | Mitotane | |||
| 38 | M | 55 | Malignant | Metastatic disease | GC | No treatment | |||
| 39 | M | 58 | Malignant | Metastatic disease | NS | Mitotane | |||
| 40 | M | 30 | Malignant | Metastatic disease | GC | Mitotane | PD | ||
| 41 | F | 44 | Malignant | Metastatic disease | NS | Mitotane + chemotherapy | ST-PD | ||
| 42 | F | 49 | Malignant | Metastatic disease | NS | Mitotane + chemotherapy | ST-PD | ||
| 43 | F | 44 | Malignant | Metastatic disease | NS | Mitotane | PD | ||
| 44 | M | 44 | Malignant | Metastatic disease | NS | Mitotane | PD | ||
| 45 | F | 45 | Malignant | Metastatic disease | A | Chemotherapy alone | |||
| 46 | M | 34 | Malignant | Metastatic disease | E2 | Mitotane + chemotherapy | PR-PD | ||
| 47 | F | 54 | Malignant | Metastatic disease | GC + A | Mitotane | |||
| 48 | F | 58 | Malignant | Metastatic disease | NS | Mitotane | |||
| 49 | F | 20 | Malignant | Metastatic disease | GC + A | No treatment | |||
| 50 | M | 46 | Malignant | Metastatic disease | NS | Mitotane | |||
| 51 | F | 54 | Malignant | Metastatic disease | GC | Mitotane |
a: arbitrary numbers; b: GC = glucocorticoid, A = androgens, E2 = estrogens, M = mineralocorticoid secretions, NS = non secreting; c: CR = complete remission, PR = partial response, ST = stabilized disease, PD = progressive disease.
This study was performed in accordance with local ethical guidelines, with the informed consent of the patients.
Methods
Plasma samples were collected after overnight fasting and before treatment in patients receiving chemo- therapy. All patients had normal liver and kidney function (plasma creatinine <110 µM).
Plasma IGFBP-2 was determined using an immuno- assay kit from Diagnostic Systems Laboratories (Web- ster, TX, USA). The intra- and interassay coefficients of variation were 6.5 and 10.3% respectively. Normal IGFBP-2 values were defined as those between -2 and +2 standard deviation score (SDS) as calculated from the control group. For the follow-up study, changes in IGFBP-2 levels (AIGFBP-2) were calculated as follows: AIGFBP-2 = ((IGFBP-2 level in sample 2-IGFBP-2 level in sample 1)/IGFBP-2 level in sample 1)x 100.
Plasma IGF-I was determined using an immuno- radiometric assay after an acid-ethanol extraction (Immunotech, Marseille, France). The intra- and interassays coefficients of variation were 7.2 and 12.4% respectively.
The hormone secretion profile included serum cortisol and 24 h urinary free cortisol, testosterone, dehydroepiandrosterone sulfate (SDHA), androstene- dione, 17ß-estradiol, aldosterone, 11-deoxycortisol and 11-deoxycorticosterone.
Statistical analysis
All analyses were performed using the Statview statistical package (Abacus Concepts, Inc., Berkeley, CA, USA). Data indicated in the text represent means ± standard deviation. Differences between the control group and the groups of patients were tested with the non-parametric Mann-Whitney U test. The correlation between IGFBP-2 and IGF-I or survival was evaluated by linear regression. Statistical significance was taken at P < 0.05.
Results
IGFBP-2 levels in controls and patients with adrenocortical tumors
Plasma IGFBP-2 concentration was determined in healthy controls and patients with adrenocortical tumors (Fig. 1). In the patient and control groups,
3000
2500
2000
IGFBP-2 (ng/ml)
1500
1000
500
0
healthy controls
complete remission (group 1)
< 50 g
150 - 300
g
localized tumors (group 2)
metastatic tumors (group 3)
600
500
O
400
IGF-I (ng/ml)
300
8
200
100
0
20 - 30
30 - 60
Age (years)
60 - 80
most subjects (90 and 85% respectively) were under the age of 60 years, so plasma IGFBP-2 concentrations did not vary significantly with age ((26) and data not shown).
In healthy controls, mean IGFBP-2 plasma concen- tration was 470 ± 130 ng/ml (-2 to +2 SDS: 210- 730 ng/ml). Plasma IGFBP-2 levels did not differ significantly between healthy controls and patients with complete remission or localized tumors (group 1, mean IGFBP-2 = 612 ± 265 ng/ml; group 2, mean IGFBP-2 = 572 ± 200ng/ml). In contrast, patients with metastatic tumors (group 3) had significantly higher levels of IGFBP-2 than the control group (mean IGFBP-2 = 1314 ± 554 ng/ml; P < 0.001). In group 3, plasma IGFBP-2 levels were found to be negatively correlated with survival (R2 = 0.308; P = 0.002; mean survival = 8.3 + 4.7 months).
In the group of patients with localized tumors (group 2), preoperative IGFBP-2 levels did not correlate with tumor weight or histological grade (Weiss score). Five patients had tumors with histological features of malignancy, but only one of them (patient 23, Table 1) had high IGFBP-2 plasma levels before surgery. For this patient, surgery confirmed the tumor stage (stage II) and histological examination indicated a Weiss score of 5 including invasion of the tumor capsule.
Analysis of individual IGFBP-2 values showed that 5 of 28 (17.8%) patients with metastatic tumor dissemi- nation had normal IGFBP-2 levels. Conversely, in the group of patients in complete remission, 2 of 15 (13.3%) had high plasma levels of IGFBP-2. These two patients (patients 3 and 11, Table 1) had no metastatic spread at the time of the study as assessed by complete imaging screening. Patient 11 had been successfully treated for a localized malignant tumor (stage II) with a
follow-up period of 11 months and patient 3 for a benign tumor with a follow-up period of 7 months.
Factors associated with high plasma IGFBP-2 concentration
Prolonged fasting and malnutrition may increase circulating IGFBP-2 levels so it was important to evaluate the nutritional status of each patient (30, 31). Because IGF-I is a good nutritional marker, IGF-I levels were determined for all patients (32) (Fig. 2). Plasma IGFBP-2 concentration was found to be negatively correlated with IGF-I (R2 = 0.22, P = 0.0029). However, 16 of 26 (61.5%) patients with high IGFBP-2 levels had normal or high levels of IGF-I, indicating a good nutritional status.
Hormone secretion was evaluated for all patients. In patients with adrenocortical tumors (group 2 and 3; n = 36), 16 had non-secreting tumors and 20 had hormonally active tumors: 16 secreted glucocorticoid with or without androgens, two secreted estrogens and two secreted androgens only. No significant difference in IGFBP-2 level was found between patients with non- secreting tumors and those with hormonally active tumors. In the same group of patients, there was no significant difference in IGFBP-2 levels between untreated patients (n=14) and those treated with mitotane (n = 22).
IGFBP-2 levels during follow-up in patients with adrenocortical tumors
Figure 3 shows the changes in IGFBP-2 levels in 17 patients for whom a follow-up study was performed
2000
Complete remission
Stable disease n=4
n=6
4000
IGFBP-2 (ng/ml)
1500
IGFBP-2 (ng/ml)
3000
1000
O
o
2000
O
O
O
500
8
1000
O
0
0
S1
S2
S1
S2
4000
Partial response n=2
4000
Progressive disease n=11
IGFBP-2 (ng/ml)
3000
IGFBP-2 (ng/ml)
3000
2000
O
2000
1000
O
O
O
1000
0
0
S1
S2
S1
S2
(Table 1). Five of the six patients who remained in complete remission during the follow-up period had IGFBP-2 values consistently within the normal range (mean AIGFBP-2 = - 8%). During the follow-up study, four patients had stable disease with corresponding stable IGFBP-2 levels (mean AIGFBP-2 = - 5%) and two patients presented a partial response to treatment with a decrease in plasma IGFBP-2 concentration over the same period (AIGFBP-2 = - 48 and -27%). In the group of patients with progressive disease (n = 11), IGFBP-2 levels correlated with the progression of the disease in six patients (mean AIGFBP-2 = +142%). For the other five patients, plasma IGFBP-2 concentration was within the normal range or remained stable despite the progression of metastasis (mean AIGFBP-2 = +13.7%).
Discussion
High levels of circulating IGFBP-2 have been reported in various malignancies (16, 21-26). We have previously shown that malignant adrenocortical tumors have a high IGFBP-2 protein content, suggest- ing that circulating IGFBP-2 is a potentially valuable tumor marker in adrenocortical carcinoma (10).
In this study, we found high plasma IGFBP-2 levels specifically in patients with malignant metastatic adrenocortical tumors, IGFBP-2 levels being negatively correlated with survival in these patients.
Several lines of evidence support the notion that in patients with adrenocortical carcinoma, circulating IGFBP-2 originates from the tumor. First, malignant adrenocortical tumors and the H295R cell line, which is derived from a human adrenocortical carcinoma, contain large amounts of IGFBP-2 protein (5, 10). Second, in the follow-up study, IGFBP-2 levels changed in accordance with tumor evolution in most of the situations studied. Third, human IGFBP-2 has been detected in the serum of nude mice bearing H295R tumor cell xenografts (33).
Several factors in addition to tumor load are known to affect the levels of circulating IGFBP-2 and may have increased IGFBP-2 concentration in our patients. None of them had renal or hepatic dysfunctions which may elevate IGFBP-2 levels (34, 35). IGFBP-2 levels increase with age (34) but in this study, most of the patients were under the age of 60 years and there is no significant difference in IGFBP-2 levels within this age range (26).
Malnutrition and cachexia are known to increase IGFBP-2 levels and occur frequently in patients with extensive tumors (30, 31). We found a negative correla- tion between plasma IGFBP-2 concentration and the concentration of the nutritional marker IGF-I. This suggests that malnutrition probably affected circulating IGFBP-2 levels in some of the patients with adrenocortical tumors, mostly those with advanced metastatic disease.
However, 61.5% of the patients with high plasma IGFBP-2 levels had normal or high IGF-I levels reflecting a good nutritional status. This suggests that malnutrition is not the major factor responsible for high plasma IGFBP-2 levels in these patients.
Acute glucocorticoid administration has been shown to decrease IGFBP-2 levels (36). However, high levels of serum IGFBP-2 have been measured in patients with Cushing’s disease ((37) and our unpublished results). If long-term glucocorticoid secretion is responsible for elevated circulating IGFBP-2 in these patients, it may also account for increased IGFBP-2 levels in patients with glucocorticoid-secreting adrenocortical tumors. How- ever, in this study, there was no difference in plasma IGFBP-2 level between patients with glucocorticoid- secreting tumors and patients with non-secreting tumors, suggesting that glucocorticoid secretion by adrenocortical tumors had no major effect on circulating IGFBP-2. Similarly, mitotane treatment, which inhibits steroidogenesis, did not seem to affect IGFBP-2 levels.
Altogether, these observations indicate that tumor stage is the predominant factor influencing IGFBP-2 levels in patients with adrenocortical carcinoma.
Another question addressed in this study was that of the value of plasma IGFBP-2 for diagnosing malig- nancy in preoperative localized tumors and for the follow-up of patients.
In the small group of patients with localized adrenocortical tumors, five patients had limited tumors with histological features of malignancy but only one patient had high plasma IGFBP-2 levels. We found no correlation between tumor weight or histological grade and IGFBP-2 levels in this group. Thus, plasma IGFBP- 2 cannot be regarded as a marker of malignancy in localized adrenocortical tumors.
In patients with metastatic disease, we found a significant negative correlation between IGFBP-2 levels and survival suggesting that, in these patients, circulating IGFBP-2 levels reflected tumor extension. However, analysis of individual IGFBP-2 values showed that five patients (17.8%) with metastatic tumors had normal IGFBP-2 levels. Four of these five patients were considered to have stabilized disease under mitotane treatment or chemotherapy at the time of the study. Interestingly, these five patients had a significant longer survival than metastatic patients with high IGFBP-2 levels (12.4 months versus 7.4 months; P = 0.03). In the follow-up study, 5 of 11 patients (45%) had no increase in IGFBP-2 levels despite progression of the disease. Thus, although circulating IGFBP-2 concen- tration correlates with tumor extension, it has a poor sensitivity as a tumor marker, precluding its use in the follow-up of patients with adrenocortical carcinoma.
These conclusions are consistent with results obtained for other malignancies. In a study of 50 children with acute lymphoblastic leukemia (ALL), Wex et al. found that 40% of the patients had normal IGFBP- 2 levels at the time of diagnosis, suggesting low
sensitivity of circulating IGFBP-2 concentration (38). Similarly, Mohnike et al. studied four patients with ALL relapse and found only one patient with high serum IGFBP-2 levels (25). Ho et al. compared serum IGFBP-2 and PSA levels in patients with prostate cancer and concluded that serum IGFBP-2 was less sensitive as a tumor marker than PSA (26). Similar conclusions were drawn from a study on ovarian tumors (24).
In the group of patients with complete remission, two patients (13.3%) had high plasma IGFBP-2 levels. The reasons for the high IGFBP-2 levels in these two patients are unclear. Both had good nutritional status. One patient (patient 11; Table 1) had been treated successfully for a malignant tumor with no sign of recurrence at the time of the study. The other patient (patient 3; Table 1) had high IGFBP-2 levels (1450 ng/ ml) despite complete removal of a benign tumor. This patient had severe hypertension treated with several antihypertensive drugs, which may have interfered with hepatic IGFBP-2 production or clearance.
In conclusion, this study indicates that tumor stage is the predominant factor influencing IGFBP-2 levels in patients with adrenocortical carcinoma, and that, in these patients, increased plasma IGFBP-2 levels are associated with a poor survival. However, plasma IGFBP-2 is less sensitive than expected for a tumor marker, which may limit its value in the diagnosis and follow-up of patients with adrenocortical carcinoma.
Acknowledgements
The authors wish to thank L Perin and R Christol for their technical assistance and all the clinicians who provided plasma samples for this study. This work was supported by Assistance Publique-Hôpitaux de Paris (Contrat de Recherche Clinique Nos 97133 and 97134), by the University of Paris VI, Faculté Saint- Antoine (UPRES EA 1531), by Association de Recherche contre le Cancer (No1364) and by Pro- gramme Hospitalier de Recherche Clinique grant AOM95201 for the COMETE network.
References
1 Latronico AC & Chrousos GP. Extensive personal experience: adrenocortical tumors. Journal of Clinical Endocrinology and Metabolism 1997 82 1317-1324.
2 Luton JP, Cerdas S, Billaud L, Thomas G, Guilhaume B, Bertagna X, et al. Clinical features of adrenocortical carcinoma, prognosis factors, and the effects of mitotane therapy. New England Journal of Medicine 1990 332 1195-1201.
3 Bonacci R, Gigliotti A, Baudin E, Wion-Barbot N, Emy P, Bonnay M. et al. Cytotoxic therapy with etoposide and cisplatin in advanced adrenocortical carcinoma. British Journal of Cancer 1998 78 546-549.
4 Gicquel C, Le Bouc Y, Luton JP & Bertagna X. Pathogenesis and treatment of adrenocortical carcinoma. Current Opinion in Endocrinology and Diabetes 1998 5 189-196.
5 Logié A, Boulle N, Gaston V, Perin L, Boudou P, Le Bouc Y, et al. Autocrine role of IGF-II in proliferation of human adrenocortical
carcinoma NCI H295R cell line. Journal of Molecular Endocrin- ology 1999 23 23-32.
6 Ilvesmäki V, Kahri AI, Miettinen PJ & Voutilainen R. Insulin-like growth factors (IGFs) and their receptors in adrenal tumors: High IGF-II expression in functional adrenocortical carcinomas. Journal of Clinical Endocrinology and Metabolism 1993 77 852-858.
7 Gicquel C, Bertagna X, Schneid H, Leblond-Francillard M, Luton JP, Girard F. et al. Rearrangements at 11p15 locus and overexpression of Insulin like growth factor-II gene in sporadic adrenocortical tumors. Journal of Clinical Endocrinology and Metabolism 1994 78 1444-1453.
8 Gicquel C, Raffin-Sanson ML, Gaston V, Bertagna X, Plouin PF, Schlumberger M. et al. Structural and functional abnormalites at 11p15 are associated with the malignant phenotype in sporadic adrenocortical tumors. Study on a series of 82 tumors. Journal of Clinical Endocrinology and Metabolism 1997 82 2559-2565.
9 Weber MM, Auernhammer CJ, Kiess W & Engelhardt D. Insulin- like growth factor receptors in normal and tumorous adult human adrenocortical glands. European Journal of Endocrinology 1997 136 296-303.
10 Boulle N, Logié A, Gicquel C, Perin L & Le Bouc Y. Increased levels of insulin-like growth factor-II (IGF-II) and IGF-binding protein-2 are associated with malignancy in sporadic adrenocortical tumors. Journal of Clinical Endocrinology and Metabolism 1998 83 1713-1720.
11 Bertagna C & Orth DN. Clinical and laboratory findings and results of therapy in 58 patients with adrenocortical tumors admitted to a single medical center (1951-1978). American Journal of Medicine 1981 71 855-875.
12 Freeman DA. Steroid hormone-producing tumors in man. Endocrine Reviews 1986 7 204-219.
13 Jones JI & Clemmons DR. Insulin-like growth factors and their binding proteins: biological actions. Endocrine Reviews 1995 16 3-34.
14 Kelley KM, Oh Y, Gargosky SE, Gucev Z, Matsumoto T, Hwa V. et al. Insulin-like growth factor-binding proteins (IGFBPs) and their regulatory dynamics. International Journal of Biochem- istry and Cell Biology 1996 28 619-637.
15 Reeve JG, Kirby LB, Brinkman A, Hughes SA, Schwander J & Bleehen NM. Insulin-like growth factor binding protein gene expression and protein production by human tumour cell lines. International Journal of Cancer 1992 51 818-821.
16 Müller HL, Oh Y, Lehrnbecher T, Blum WF & Rosenfeld RG. Insulin-like growth factor-binding protein-2 concentrations in cerebrospinal fluid and serum of children with malignant solid tumors or acute leukemia. Journal of Clinical Endocrinology and Metabolism 1994 7 428-434.
17 Karasik A, Menczer J, Pariente C & Kanety H. Insulin-like growth factor-I (IGF-I) and IGF-binding protein-2 are increased in cyst fluids of epithelial ovarian cancer. Journal of Clinical Endocrinology and Metabolism 1994 78 271-276.
18 Kanety H, Kattan M, Goldberg I, Kopolovic J, Ravia J, Menczer J. et al. Increased insulin-like growth factor binding protein-2 (IGFBP-2) gene expression and protein production lead to high IGFBP-2 content in malignant ovarian cyst fluid. British Journal of Cancer 1996 73 1069-1073.
19 Vincent TS, Garvin AJ, Gramling TS, Hazen-Martin DJ, Re GG & Sens DA. Expression of Insulin-like growth factor binding protein 2 (IGFBP-2) in Wilms’ tumors. Pediatric Pathology 1994 14 723- 730.
20 Tennant MK, Thrasher JB, Twomey PA, Birnbaum RS & Plymate SR. Insulin-like growth factor-binding protein-2 and -3 expression in benign human prostate epithelium, prostate intraepithelial neoplasia, and adenocarcinoma of the prostate. Journal of Clinical Endocrinology and Metabolism 1996 81 411-420.
21 Cohen P, Peehl DM, Stamey TA, Wilson KF, Clemmons DR & Rosenfeld RG. Elevated levels of Insulin-like growth factor-binding protein-2 in the serum of prostate cancer patients. Journal of Clinical Endocrinology and Metabolism 1993 76 1031-1035.
22 Zumkeller W, Schwander J, Mitchell CD, Morrell DJ, Schofield PN & Preece MA. Insulin-like growth factor (IGF)-I, -II and IGF
binding protein-2 (IGFBP-2) in the plasma of children with Wilms’ tumour. European Journal of Cancer 1993 29 1973-1977.
23 El Atiq F, Garrouste F, Remacle-Bonnet M, Sastre B & Pommier G. Alterations in serum levels of insulin-like growth factors and insulin-like growth factor-binding proteins in patients with color- ectal cancer. International Journal of Cancer 1994 57 491-497.
24 Flyvbjerg A, Mogensen O, Mogensen B & Nielsen OS. Elevated serum insulin-like growth factor-binding protein 2 (IGFBP-2) and decreased IGFBP-3 in epithelial ovarian cancer: correlation with cancer antigen 125 and tumor-associated trypsin inhibitor. Journal of Clinical Endocrinology and Metabolism 1997 82 2308-2313.
25 Mohnike KL, Kluba U, Mittler U, Aumann V, Vorwerk P & Blum WF. Serum levels of insulin-like growth factor-I, -II and insulin-like growth factor binding proteins-2 and -3 in children with acute lymphoblastic leukaemia. European Journal of Pediatry 1996 155 81-86.
26 Ho PJ & Baxter RC. Insulin-like growth factor-binding protein-2 in patients with prostate carcinoma and benign prostatic hyperplasia. Clinical Endocrinology 1997 46 333-342.
27 Macfarlane DA. Cancer of the adrenal cortex. The natural history, prognosis and treatment in a study of fifty-five cases. Annals of the Royal College of Surgeons of England 1958 23 155-186.
28 Weiss LM. Comparative histologic study of 43 metastasizing and non metastasizing adrenocortical tumors. American Journal of Surgical Pathology 1984 8 163-169.
29 World Health Organisation International histological clasification of tumors. Geneva: Worth Health Organisation 1969-1981. Berlin: Springer-Verlag, 1988.
30 Clemmons DR, Snyder DK & Busby WH. Variables controlling the secretion of insulin-like growth factor binding protein-2 in normal human subjects. Journal of Clinical Endocrinology and Metabolism 1991 73 727-733.
31 Counts DR, Gwirtsman H, Carlsson LMS, Lesem M & Cutler GB. The effects of anorexia nervosa and refeeding on growth hormone-binding protein, the insulin-like growth factors (IGFs), and the IGF-binding proteins. Journal of Clinical Endo- crinology and Metabolism 1992 75 762-767.
32 Thissen JP, Ketelslegers JM & Underwood LE. Nutritional regulation of the insulin-like growth factors. Endocrine Reviews 1994 15 80-101.
33 Logié A, Boudou P, Boccon-Gibod L, Baudin E, Vassal G, Schlumberger M, Le Bouc Y & Gicguel C. Establishment and characterization of a human adrenocortical carcinoma xeno- graft. Endocrinology 2000 141 3165-3171.
34 Blum WF, Horn N, Kratzsch J, Jorgensen JOL, Juul A, Teale D. et al. Clinical studies of IGFBP-2 by radioimmunoassay. Growth Regulation 1993 3 100-104.
35 Kratzsch J, Blum WF, Schenker E & Keller E. Regulation of growth hormone (GH), insulin-like growth factor (IGF)I, IGF binding proteins-1, -2, -3 and GH binding protein during progression of liver cirrhosis. Experimental and Clinical Endocrinology and Diabetes 1995 103 285-291.
36 Miell JP, Taylor AM, Jones J, Holly JMP, Gaillard RC, Pralong FP, et al. The effects of dexamethasone treatment on immunoreactive and bioactive insulin-like growth factors (IGFs) and IGF-binding proteins in normal male volunteers. Journal of Endocrinology 1993 136 525-533.
37 Bang P, Degerblad M, Thoren M, Schwander J, Blum W & Hall K. Insulin-like growth factor (IGF) I and II and IGF binding protein (IGFBP) 1, 2 and 3 in serum from patients with Cushing’s syndrome. Acta Endrocrinologica 1993 128 397-404.
38 Wex H, Vorwerk P, Mohnike K, Bretschneider D, Kluba U, Aumann V. et al. Elevated serum levels of IGFBP-2 found in children suffering from acute leukaemia is accompanied by the occurence of IGFBP-2 mRNA in the tumor clone. British Journal of Cancer 1998 78 515-520.