Effects of mitotane on the hypothalamic-pituitary-adrenal axis in patients with adrenocortical carcinoma.

OBJECTIVE: Mitotane, a drug used to treat adrenocortical cancer (ACC), inhibits multiple enzymatic steps of adrenocortical steroid biosynthesis, potentially causing adrenal insufficiency. Recent studies in vitro have also documented a direct inhibitory effect of mitotane at the pituitary level. The present study was aimed to assess the hypothalamic-pituitary-adrenal axis in patients with ACC receiving mitotane. DESIGN AND METHODS: We prospectively enrolled 16 patients on adjuvant treatment with mitotane after radical surgical resection of ACC, who underwent standard hormone evaluation and h-CRH stimulation. A group of 10 patients with primary adrenal insufficiency (PAI) served as controls for the CRH test. RESULTS: We demonstrated a close correlation between cortisol-binding globulin (CBG) and plasma mitotane levels, and a non-significant trend between mitotane dose and either serum or salivary cortisol in ACC patients. We did not find any correlation between the dose of cortisone acetate and either ACTH or cortisol levels. ACTH levels were significantly higher in patients with PAI than that in patients with ACC, both in baseline conditions (88.99 (11.04-275.00) vs 24.53 (6.16-121.88) pmol/L, P = 0.031) and following CRH (158.40 (34.32-275.00) vs 67.43 (8.8-179.52) pmol/L P = 0.016). CONCLUSIONS: The observation of lower ACTH levels in patients with ACC than that in patients with PAI, both in basal conditions and after CRH stimulation, suggests that mitotane may play an inhibitory effect on ACTH secretion at the pituitary levels. In conclusion, the present study shows that mitotane affects the HPA axis at multiple levels and no single biomarker may be used for the assessment of adrenal insufficiency.

Topoisomerase 2α and thymidylate synthase expression in adrenocortical cancer.

Topoisomerase II alpha (TOP2A) and thymidylate synthase (TS) are known prognostic parameters in several tumors and also predictors of efficacy of anthracyclines, topoisomerase inhibitors and fluoropirimidines, respectively. Expression of TOP2A and TS mRNA was assessed in 98 patients with adrenocortical carcinoma (ACC) and protein expression was assessed by immunohistochemistry in a subset of 39 tumors. Ninety-two patients were radically resected for stage II-III disease and 38 of them received adjuvant mitotane. Twenty-six patients with metastatic disease received the EDP-M (etoposide, doxorubicin, Adriamycin, cisplatin plus mitotane). TOP2A and TS expression in ACC tissue was directly correlated with the clinical data. Both markers were not associated with either disease free survival (DFS) or overall survival (OS) in multivariate analyses and failed to be associated to mitotane efficacy. Disease response or stabilization to EDP-M treatment was observed in 12/17 (71%) and 1/9 (11%) patients with high and low TOP2A expressing tumors (P = 0.0039) and 9/13 (69%) and 4/13 (31%) patients with high and low TS expressing ACC, respectively (P = 0.049). High TOP2A expression was significantly associated with longer time to progression (TTP) after EDP-M. TOP2A and TS proteins assessed by immunohistochemistry significantly correlated with mRNA expression. Immunohistochemical TOP2A expression was associated with a non-significant better response and longer TTP after EDP-M. TOP2A and TS were neither prognostic nor predictive of mitotane efficacy in ACC patients. The predictive role of TOP2A expression of EDP-M activity suggests a significant contribution of Adriamycin and etoposide for the efficacy of the EDP scheme.

Long-Term Outcomes of Adjuvant Mitotane Therapy in Patients With Radically Resected Adrenocortical Carcinoma.

CONTEXT: In 2007, a retrospective case-control study provided evidence that adjuvant mitotane prolongs recurrence-free survival (RFS) in patients with radically resected adrenocortical carcinoma (ACC). OBJECTIVE AND DESIGN: We aimed to confirm the prognostic role of adjuvant mitotane in the same series after 9 additional years of follow-up. SETTING, PATIENTS, AND INTERVENTIONS: One hundred sixty-two ACC patients who did not recur or die after a landmark period of 3 months were considered. Forty-seven patients were enrolled in four Italian centers where adjuvant mitotane was routinely recommended (mitotane group), 45 patients in four Italian centers where no adjuvant strategy was undertaken (control group 1), and 70 German patients left untreated after surgery (control group 2). MAIN OUTCOME MEASURES: The primary aim was RFS, the secondary was overall survival. RESULTS: An increased risk of recurrence was found in both control cohorts [group 1: hazard ratio (HR) = 2.98; 95% confidence interval (CI), 1.75 to 5.09; P < 0.0001; group 2: HR = 2.61; 95% CI, 1.56 to 4.36; P < 0.0001] compared with the mitotane group. The risk of death was higher in control group 1 (HR = 2.03; 95% CI, 1.17 to 3.51; P = 0.011) but not in control group 2 (HR = 1.60; 95% CI, 0.94 to 2.74; P = 0.083), which had better prognostic factors and more aggressive treatment of recurrences than control group 1. The benefit of adjuvant mitotane on RFS was observed regardless of the hormone secretory status. CONCLUSIONS: Adjuvant mitotane is associated with prolonged RFS, without any apparent influence by the tumor secretory status. The retrospective nature of the study is a major limitation.

Validation of the prognostic role of the "Helsinki Score" in 225 cases of adrenocortical carcinoma.

Adrenocortical carcinoma patient prognosis is extremely variable and poorly predictable. The newly introduced Helsinki Score is the first so far proposed diagnostic and prognostic system based on the combined evaluation of morphological (mitoses and necrosis) and immunohistochemical (Ki-67) parameters. The aim of the study was to validate the prognostic role of the Helsinki Score for adrenocortical carcinoma characterization. Thus, 225 adrenocortical carcinomas were reclassified using the Weiss Score and the Helsinki Score (3× mitotic count + 5 × necrosis + Ki-67 index). At univariate analysis, statistically significant prognostic values were observed at the log-rank test for mitotic count (cutoff values: <6 and ≥55; P<.0001), Ki-67 (cutoff values: <20 and ≥50; P<.0001), Weiss Score (cutoff values: <5 and ≥8; P<.0001), Helsinki Score (cutoff values: <13 and ≥19; P<.0001), histological variant (conventional versus oncocytic; P=.009), necrosis (P=.001), and stage (P=.005). Cox multivariate analysis using a backward stepwise selection method retained only Helsinki Score and Weiss Score as predictors of poor prognosis (P<.0001 and P=.0005, respectively). Helsinki Score (with a threshold of 28.5 points; area under the curve [AUC]=0.729, 95% confidence interval=0.66-0.79) and Ki-67 (with a threshold of 20.5%; AUC=0.727, 95% confidence interval=0.66-0.79) showed the best and equivalent AUCs predicting disease-related deaths determined using receiver operating characteristic statistics. In conclusion, the Helsinki Score is a valuable system to predict prognosis in adrenocortical carcinoma, outperforming the currently established prognostic parameters.

Pitfalls in the diagnosis of adrenocortical tumors: a lesson from 300 consultation cases.

The correct pathologic classification of adrenocortical carcinoma (ACC) is relevant to establish an early therapeutic strategy of this rare malignancy. The aim of the study was to assess the most frequent pitfalls in ACC diagnosis reviewing a large consecutive series of 300 cases with an original diagnosis or a clinical suspect of ACC, which were sent in consultation to our institution between 2004 and 2014. A major disagreement that significantly modified the clinical management of patients was recorded in 26 cases (9%). The most common pitfall (10 cases) was to distinguish ACC from pheochromocytoma and vice versa. Seven other cases diagnosed as ACC were reclassified as metastases from other primaries and primary adrenal soft tissue tumors (including 3 angiosarcomas). Finally, 5 adrenocortical adenomas were reclassified into carcinomas, and 4 ACCs were converted into adenomas. Minor disagreements were mostly related to the identification of ACC variants (up to 32% of cases of adrenocortical tumors in the present series). Moreover, more than 50% of ACC cases lacked Ki-67. In conclusion, our results indicate that, in the presence of a histologically suspected ACC, a special attention should be devoted to exclude metastatic and soft tissue tumors and pheochromocytoma (in this latter case with special reference to the oncocytic variant of adrenocortical tumors). Moreover, pathologists should be aware of the major role of Ki-67 in determining prognosis and in selecting patients to the most appropriate treatment.

Evaluation of Midnight Salivary Cortisol as a Predictor Factor for Common Carotid Arteries Intima Media Thickness in Patients with Clinically Inapparent Adrenal Adenomas.

Purpose. The aim of the present study was to investigate the atherosclerotic vascular damage in a consecutive series of patients with AI and to correlate it with MSC. Methods. We studied 32 patients with AI matched with control subjects for age, sex, and cardiovascular risk factors. Either patients or control subjects underwent MSC measurement as outpatients and carotid arteries ultrasound (US) imaging studies. Results. The patients with AI had higher mean carotid artery IMT values and higher MSC levels than control subjects. In a multivariate analysis performed in AI age was the best predictor for IMT. We have stratified patients and control subjects by age (<60 yrs and ≥60 yrs). The patients showed significantly higher MSC levels than controls in both groups, whereas significantly higher IMT values were observed only in older subjects. Conclusions. Patients with AI have signs of accelerated atherosclerosis. Patients older than 60 years seem more susceptible to the possible detrimental effect of subclinical hypercortisolism on cardiovascular system. The MSC levels are not a strong predictor of the accelerated atherosclerosis, but they seem to indicate the subtle but not autonomous cortisol excess that may potentially raise the cardiovascular risk.

Practical treatment using mitotane for adrenocortical carcinoma.

PURPOSE OF REVIEW: Description of novel findings about the mechanism of action of mitotane and its activity as an adjunctive postoperative measure, or for treatment of advanced adrenocortical carcinoma. RECENT FINDINGS: Several in-vitro studies have shown that mitotane suppresses gene transcription of different enzymatic steps of the steroidogenetic pathway. Moreover, mitotane induces CYP3A4 expression, thus accelerating the metabolic clearance of a variety of drugs including steroids. Retrospective studies provided evidence that adjunctive mitotane can prolong recurrence-free survival of treated patients. The concept of a therapeutic window of mitotane plasma concentrations was confirmed also for adjunctive treatment, but the relationship between mitotane concentration and given dose is loose. Genetic variability of the P450-dependent enzymes metabolizing mitotane may explain individual differences. SUMMARY: Mitotane concentration of 14-20  mg/l should be reached and maintained during treatment also in an adjunctive setting. In advanced adrenocortical carcinoma, a high-dose starting regimen should be employed when mitotane is used as monotherapy. The combination of mitotane with other drugs should consider the possibility of pharmacologic interactions due to mitotane-induced activation of drug metabolism. This concept applies also to steroid replacement in mitotane-treated patients, who need higher doses to adjust for increased steroid metabolism.

Growth hormone values after an oral glucose load do not add clinically useful information in patients with acromegaly on long-term somatostatin receptor ligand treatment.

The optimal method of assessing GH status in acromegalic patients receiving medical therapy with somatostatin analogs (SSA) has been matter of debate. The aim of the study has been to investigate whether OGTT may add information in patients with discordant random GH (GHr) and IGF values. Moreover, we evaluated the association of GH nadir with the prevalence of co-morbidities observed in acromegalic patients on SSA therapy. We evaluated 130 patients with proven diagnosis of acromegaly on SSA. The patients were subdivided in three groups: patients with controlled disease (both safe random GH and normal IGF-I, group A, 20.0 %), patients with uncontrolled disease (both high random GH and IGF-I, group B, 34.6 %), and patients with discordant random GH and IGF-I values (group C, 35.4 %). A high concordance rate for GH nadir with random GH and IGF-I was observed in group B, while a significant reduced concordance rate has been observed in group A (100 % sensitivity, 64.5 % specificity). By contrast, in group C, we observed concordant results between GH nadir and IGF-I only in 14/59 patients. In group A, the prevalence of diabetes was lower than in group B or C. Safe random GH was the only single criteria associated with a lower prevalence of diabetes. Discrepant IGF-I and either GH nadir or random GH values are frequently observed in acromegalic patients treated with SSA. Concordant IGF-I and random GH may influence the prevalence of metabolic complications. GH nadir measurement may help to interpret discrepancies between random GH and IGF-I data only in few cases.

Influence of the CYP2B6 polymorphism on the pharmacokinetics of mitotane.

OBJECTIVE: The aim of this study was to assess the potential impact of the pharmacogenetic variability of CYP2B6 and ABCB1 genes on the pharmacokinetics of mitotane. METHODS: A retrospective analysis was carried out on 27 patients with adrenocortical carcinoma on postoperative adjunctive mitotane. CYP2B6 and ABCB1 polymorphisms were genotyped and tested for an association with plasma trough concentration after 3, 6, 9, and 12 months of therapy. RESULTS: Patients with the GT/TT genotype had higher mitotane plasma concentrations compared with patients with GG at 3 months (14.80 vs. 8.01 µg/ml; P=0.008) and 6 months (17.70 vs. 9.75 µg/ml; P=0.015). Multivariate logistic regression analysis showed that only the CYP2B6 rs3745274GT/TT genotype (odds ratio=10.7; P=0.017) was a predictor of mitotane plasma concentrations of at least 14 µg/ml after 3 months of treatment. Mitotane concentrations were not influenced by the polymorphisms of the ABCB1 gene. CONCLUSION: Evaluation of the CYP2B6 polymorphism enabled prediction of the individual response to adjuvant mitotane treatment.

Gemcitabine plus metronomic 5-fluorouracil or capecitabine as a second-/third-line chemotherapy in advanced adrenocortical carcinoma: a multicenter phase II study.

Adrenocortical carcinoma (ACC) is a rare neoplasm characterized by poor prognosis. First-line systemic treatments in advanced disease include mitotane, either alone or in combination with chemotherapy. Studies evaluating second-line therapy options have obtained disappointing results. This trial assessed the activity and toxicity of gemcitabine plus metronomic fluoropyrimidines in heavily pretreated advanced ACC patients. From 1998 to 2008, 28 patients with advanced ACC progressing after mitotane plus one or two systemic chemotherapy lines were enrolled. They received a combination of i.v. gemcitabine (800 mg/m(2), on days 1 and 8, every 21 days) and i.v. 5-fluorouracil protracted infusion (200 mg/m(2)/daily without interruption until progression) in the first six patients, or oral capecitabine (1500 mg/daily) in the subsequent patients. Mitotane administration was maintained in all cases. The rate of non-progressing patients after 4 months of treatment was 46.3%. A complete response was observed in 1 patient (3.5%); 1 patient (3.5%) obtained a partial regression, 11 patients (39.3%) obtained a disease stabilization and 15 patients (53.7%) progressed. Treatment was well tolerated, with grade III and IV toxicities consisting of leukopenia in six patients (21.4%), thrombocytopenia in one patient (3.5%), and mucositis in one patient (3.5%). Median time to progression and overall survival in the patient population were 5.3 (range: 1-43) and 9.8 months (range: 3-73) respectively. Gemcitabine plus metronomic fluoropyrimidines is a well-tolerated and moderately active regimen in heavily pretreated ACC patients.

Retrospective evaluation of the outcome of open versus laparoscopic adrenalectomy for stage I and II adrenocortical cancer.

BACKGROUND: Although there is consensus that laparoscopy is the standard of care for the resection of benign adrenal tumours, there is controversy regarding the role of laparoscopy for the resection of adrenocortical cancer (ACC). OBJECTIVE: The aim of the present study was to review the ACC database of the San Luigi Hospital to compare the oncologic effectiveness of open adrenalectomy (OA) versus laparoscopic adrenalectomy (LA) in the treatment of patients with stage I and II ACC. DESIGN, SETTING, AND PARTICIPANTS: We performed a retrospective analysis involving 43 patients with stage I and II ACC who had undergone radical surgery. INTERVENTION: The patients were stratified into two groups according to the surgical procedure. The "open group" consisted of patients treated with OA; the "lap group" consisted of patients treated with LA. MEASUREMENTS: Oncologic effectiveness of the procedures was tested comparing the recurrence-free survival of patients treated with OA versus LA. Secondary outcome measures were differences in terms of type of recurrence and overall survival. RESULTS AND LIMITATIONS: The open group consisted of 25 patients and the lap group of 18 patients. The two groups were comparable in terms of demographic data. The median follow-up was 38 mo in the open group and 30 mo in the lap group. Recurrence rate was 64% in the open group and 50% in the lap group. The median recurrence-free survival was 18 mo in the open group and 23 in the lap group (p=0.8). No differences in terms of pattern of recurrences were recorded. During follow-up, 28% of the open group patients and 5% of the lap group patients died. No differences in terms of survival time were noted (p=0.3). CONCLUSIONS: The present findings provide interesting evidence that OA and LA may be comparable in terms of recurrence-free survival for patients with stage I and II ACC when the principles of surgical oncology are respected.

Prospective evaluation of mitotane toxicity in adrenocortical cancer patients treated adjuvantly.

Toxicity of adjuvant mitotane treatment is poorly known; thus, our aim was to assess prospectively the unwanted effects of adjuvant mitotane treatment and correlate the findings with mitotane concentrations. Seventeen consecutive patients who were treated with mitotane after radical resection of adrenocortical cancer (ACC) from 1999 to 2005 underwent physical examination, routine laboratory evaluation, monitoring of mitotane concentrations, and a hormonal work-up at baseline and every 3 months till ACC relapse or study end (December 2007). Mitotane toxicity was graded using NCI CTCAE criteria. All biochemical measurements were performed at our center and plasma mitotane was measured by an in-house HPLC assay. All the patients reached mitotane concentrations >14 mg/l and none of them discontinued definitively mitotane for toxicity; 14 patients maintained consistently elevated mitotane concentrations despite tapering of the drug. Side effects occurred in all patients but were manageable with palliative treatment and adjustment of hormone replacement therapy. Mitotane affected adrenal steroidogenesis with a more remarkable inhibition of cortisol and DHEAS than aldosterone. Mitotane induced either perturbation of thyroid function mimicking central hypothyroidism or, in male patients, inhibition of testosterone secretion. The discrepancy between salivary and serum cortisol, as well as between total and free testosterone, is due to the mitotane-induced increase in hormone-binding proteins which complicates interpretation of hormone measurements. A low-dose monitored regimen of mitotane is tolerable and able to maintain elevated drug concentrations in the long term. Mitotane exerts a complex effect on the endocrine system that may require multiple hormone replacement therapy.

The combined low-dose dexamethasone suppression corticotropin-releasing hormone test as a tool to rule out Cushing's syndrome.

OBJECTIVE: It remains to be evaluated whether the combined low-dose dexamethasone suppression corticotropin-releasing hormone test (LDDST-CRH test) may add to the diagnostic approach of patients suspected to have Cushing's syndrome (CS). The aim of the present study was to evaluate whether the LDDST-CRH test may have a place in the diagnostic strategy of CS. DESIGN: Prospective evaluation of a consecutive series of patients with suspected CS from 2004 to 2006. METHODS: All the subjects underwent the same screening protocol including 1 mg dexamethasone suppression test, 24-h urinary free cortisol (UFC), and midnight serum cortisol, followed by the LDDST-CRH test whose results were not used to establish a definitive diagnosis. Plasma dexamethasone concentration was measured 2 h after the last dose of dexamethasone. Patients qualified for CS when at least two screening tests were positive. RESULTS: Sixteen patients had CS while in the remaining 15 subjects CS was excluded. Even if not statistically significant, the sensitivity and the negative predictive value of the cortisol 15 min after CRH were better than the other tests; on the other hand, the test specificity was lower. All of the patients classified as indeterminate were correctly diagnosed by the LDDST-CRH test. Nevertheless, the repeated assessment of the screening tests and the active follow-up gave the same correct results. In all of the patients misclassified by the LDDST-CRH test, the plasma dexamethasone concentrations were in the normal range. CONCLUSIONS: Based on our findings, we suggest that the LDDST-CRH test may still find a place as a rule-out procedure in patients who present with indeterminate results after screening and may be unavailable to repeat testing during follow-up.