Recovery of adrenal function after stopping mitotane in patients with adrenocortical carcinoma

OBJECTIVE

Mitotane is the standard therapy of adrenocortical carcinoma (ACC) due to its relative selectivity of its cytotoxic effects toward adrenocortical cells. Therefore, it virtually always leads to adrenal insufficiency. Frequency and characteristics of hypothalamic-pituitary-adrenal axis recovery after discontinuation are ill-defined.

METHODS

This was a retrospective study of patients with ACC adjuvantly treated with mitotane for ≥12 months who were disease-free at mitotane stop and had a minimum follow-up ≥1 year. Primary endpoint was adrenal recovery. Cox regression analyses were used to identify predictive factors. Moreover, mitotane plasma elimination rate and hormonal changes after mitotane stop were investigated.

RESULTS

Fifty-six patients (36 women) treated with mitotane for a median time of 25 months and an average daily dose of 2.8 g were included. Median time after discontinuation until mitotane levels dropped below 5 and 2 mg/L, and the detection limit was 152 days (interquartile range: 114-202), 280 days (192-370), and 395 days (227-546), respectively. Full adrenal recovery was documented in 32 (57%) patients after a median time of 26 months (95% confidence interval [CI] = 19.6-32.4). In 4 patients (7.1%), adrenal insufficiency persisted >5 years after discontinuation. Mitotane peak ≥ 27 mg/L significantly correlated with longer time to adrenal recovery (hazard ratio [HR] = 0.2, 95% CI = 0.1-0.8, P = .03). Twenty-seven of 38 patients (71%) followed in reference centers achieved adrenal recovery compared with only 5/18 (28%) followed up in non-reference centers (HR = 4.51, 95% CI = 1.71-11.89, P = .002). Other investigated factors were not associated with adrenal function after discontinuation.

CONCLUSIONS

Our study demonstrates that adrenal recovery occurs in most patients after stopping mitotane, particularly when followed up in specialized centers, but not in all. Elimination time of mitotane after treatment discontinuation is very long but individually quite variable.

Adjuvant mitotane versus surveillance in low-grade, localised adrenocortical carcinoma (ADIUVO): an international, multicentre, open-label, randomised, phase 3 trial and observational study

BACKGROUND

Adjuvant treatment with mitotane is commonly used after resection of adrenocortical carcinoma; however, treatment remains controversial, particularly if risk of recurrence is not high. We aimed to assess the efficacy and safety of adjuvant mitotane compared with surveillance alone following complete tumour resection in patients with adrenocortical carcinoma considered to be at low to intermediate risk of recurrence.

METHODS

ADIUVO was a multicentre, open-label, parallel, randomised, phase 3 trial done in 23 centres across seven countries. Patients aged 18 years or older with adrenocortical carcinoma and low to intermediate risk of recurrence (R0, stage I-III, and Ki67 ≤10%) were randomly assigned to adjuvant oral mitotane two or three times daily (the dose was adjusted by the local investigator with the target of reaching and maintaining plasma mitotane concentrations of 14-20 mg/L) for 2 years or surveillance alone. All consecutive patients at 14 study centres fulfilling the eligibility criteria of the ADIUVO trial who refused randomisation and agreed on data collection via the European Network for the Study of Adrenal Tumors adrenocortical carcinoma registry were included prospectively in the ADIUVO Observational study. The primary endpoint was recurrence-free survival, defined as the time from randomisation to the first radiological evidence of recurrence or death from any cause (whichever occurred first), assessed in all randomly assigned patients by intention to treat. Overall survival, defined as time from the date of randomisation to the date of death from any cause, was a secondary endpoint analysed by intention to treat in all randomly assigned patients. Safety was assessed in all patients who adhered to the assigned regimen, which was defined by taking at least one tablet of mitotane in the mitotane group and no mitotane at all in the surveillance group. The ADIUVO trial is registered with ClinicalTrials.gov, NCT00777244, and is now complete.

FINDINGS

Between Oct 23, 2008, and Dec 27, 2018, 45 patients were randomly assigned to mitotane and 46 to surveillance alone. Because the study was discontinued prematurely, 5-year recurrence-free and overall survival are reported instead of recurrence-free and overall survival as defined in the protocol. 5-year recurrence-free survival was 79% (95% CI 67-94) in the mitotane group and 75% (63-90) in the surveillance group (hazard ratio 0·74 [95% CI 0·30-1·85]). Two people in the mitotane group and five people in the surveillance group died, and 5-year overall survival was not significantly different (95% [95% CI 89-100] in the mitotane group and 86% [74-100] in the surveillance group). All 42 patients who received mitotane had adverse events, and eight (19%) discontinued treatment. There were no grade 4 adverse events or treatment-related deaths.

INTERPRETATION

Adjuvant mitotane might not be indicated in patients with low-grade, localised adrenocortical carcinoma considering the relatively good prognosis of these patients, and no significant improvement in recurrence-free survival and treatment-associated toxicity in the mitotane group. However, the study was discontinued prematurely due to slow recruitment and cannot rule out an efficacy of treatment.

FUNDING

AIFA, ENSAT Cancer Health F2-2010-259735 programme, Deutsche Forschungsgemeinschaft, Cancer Research UK, and the French Ministry of Health.

Efficacy and safety of radiation therapy in advanced adrenocortical carcinoma

BACKGROUND

International guidelines emphasise the role of radiotherapy (RT) for the management of advanced adrenocortical carcinoma (ACC). However, the evidence for this recommendation is very low.

METHODS

We retrospectively analysed all patients who received RT for advanced ACC in five European centres since 2000.

PRIMARY ENDPOINT

time to progression of the treated lesion (tTTP). Secondary endpoints: best objective response, progression-free survival (PFS), overall survival (OS), adverse events, and the establishment of predictive factors by Cox analyses.

RESULTS

In total, 132 tumoural lesions of 80 patients were treated with conventional RT (cRT) of 50-60 Gy (n = 20) or 20-49 Gy (n = 69), stereotactic body RT of 35-50 Gy (SBRT) (n = 36), or brachytherapy of 12-25 Gy (BT) (n = 7). Best objective lesional response was complete (n = 6), partial (n = 52), stable disease (n = 60), progressive disease (n = 14). Median tTTP was 7.6 months (1.0-148.6). In comparison to cRT20-49Gy, tTTP was significantly longer for cRT50-60Gy (multivariate adjusted HR 0.10; 95% CI 0.03-0.33; p < 0.001) and SBRT (HR 0.31; 95% CI 0.12-0.80; p = 0.016), but not for BT (HR 0.66; 95% CI 0.22-1.99; p = 0.46). Toxicity was generally mild and moderate with three grade 3 events. No convincing predictive factors could be established.

CONCLUSIONS

This largest published study on RT in advanced ACC provides clear evidence that RT is effective in ACC.

Somatostatin receptor-directed molecular imaging for therapeutic decision-making in patients with medullary thyroid carcinoma

BACKGROUND

Somatostatin receptor (SSTR) positron emission tomography/computed tomography (PET/CT) is increasingly deployed in the diagnostic algorithm of patients affected with medullary thyroid carcinoma (MTC). We aimed to assess the role of SSTR-PET/CT for therapeutic decision making upon restaging.

METHODS

23 pretreated MTC patients underwent SSTR-PET/CT and were discussed in our interdisciplinary tumor board. Treatment plans were initiated based on scan results. By comparing the therapeutic regimen before and after the scan, we assessed the impact of molecular imaging on therapy decision. SSTR-PET was also compared to CT portion of the SSTR-PET/CT (as part of hybrid imaging).

RESULTS

SSTR-PET/CT was superior in 9/23 (39.1%) subjects when compared to conventional CT and equivalent in 14/23 (60.9%). Those findings were further corroborated on a lesion-based level with 27/73 (37%) metastases identified only by functional imaging (equivalent to CT in the remaining 46/73 (63%)). Investigating therapeutic decision making, no change in treatment was initiated after PET/CT in 7/23 (30.4%) patients (tyrosine kinase inhibitor (TKI), 4/7 (57.2%); surveillance, 3/7 (42.8%)). Imaging altered therapy in the remaining 16/23 (69.6%). Treatment prior to PET/CT included surgery in 6/16 (37.5%) cases, followed by TKI in 4/16 (25%), active surveillance in 4/16 (25%), and radiation therapy (RTx) in 2/16 (12.5%) subjects. After SSTR-PET/CT, the therapeutic regimen was changed as follows: In the surgery group, 4/6 (66.7%) patients underwent additional surgery, and 1/6 (16.7%) underwent surveillance and TKI, respectively. In the TKI group, 3/4 (75%) individuals received another TKI and the remaining subject (1/4, 25%) underwent peptide receptor radionuclide therapy. In the surveillance group, 3/4 (75%) underwent surgery (1/4, (25%), RTx). In the RTx group, one patient was switched to TKI and another individual was actively monitored (1/2, 50%, respectively). Moreover, in the 16 patients in whom treatment was changed by molecular imaging, control disease rate was achieved in 12/16 (75%) during follow-up.

CONCLUSIONS

In patients with MTC, SSTR-PET/CT was superior to CT alone and provided relevant support in therapeutic decision-making in more than two thirds of cases, with most patients being switched to surgical interventions or systemic treatment with TKI. As such, SSTR-PET/CT can guide the referring treating physician towards disease-directed treatment in various clinical scenarios.

Management of Patients With Glucocorticoid-Related Diseases and COVID-19

The ongoing coronavirus disease 2019 (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is a global health crisis affecting millions of people worldwide. SARS-CoV-2 enters the host cells by binding to angiotensin-converting enzyme 2 (ACE2) after being cleaved by the transmembrane protease serine 2 (TMPRSS2). In addition to the lung, gastrointestinal tract and kidney, ACE2 is also extensively expressed in endocrine tissues, including the pituitary and adrenal glands. Although glucocorticoids could play a central role as immunosuppressants during the cytokine storm, they can have both stimulating and inhibitory effects on immune response, depending on the timing of their administration and their circulating levels. Patients with adrenal insufficiency (AI) or Cushing's syndrome (CS) are therefore vulnerable groups in relation to COVID-19. Additionally, patients with adrenocortical carcinoma (ACC) could also be more vulnerable to COVID-19 due to the immunosuppressive state caused by the cancer itself, by secreted glucocorticoids, and by anticancer treatments. This review comprehensively summarizes the current literature on susceptibility to and outcome of COVID-19 in AI, CS and ACC patients and emphasizes potential pathophysiological mechanisms of susceptibility to COVID-19 as well as the management of these patients in case of SARS-CoV-2. Finally, by performing an in silico analysis, we describe the mRNA expression of ACE2, TMPRSS2 and the genes encoding their co-receptors CTSB, CTSL and FURIN in normal adrenal and adrenocortical tumors (both adenomas and carcinomas).

Expression of SOAT1 in Adrenocortical Carcinoma and Response to Mitotane Monotherapy: An ENSAT Multicenter Study

CONTEXT

Objective response rate to mitotane in advanced adrenocortical carcinoma (ACC) is approximately 20%, and adverse drug effects are frequent. To date, there is no marker established that predicts treatment response. Mitotane has been shown to inhibit sterol-O-acyl transferase 1 (SOAT1), which leads to endoplasmic reticulum stress and cell death in ACC cells.

OBJECTIVE

To investigate SOAT1 protein expression as a marker of treatment response to mitotane.

PATIENTS

A total of 231 ACC patients treated with single-agent mitotane as adjuvant (n = 158) or advanced disease therapy (n = 73) from 12 ENSAT centers were included. SOAT1 protein expression was determined by immunohistochemistry on formalin-fixed paraffin-embedded specimens.

SETTING

Retrospective study at 12 ACC referral centers.

MAIN OUTCOME MEASURE

Recurrence-free survival (RFS), progression-free survival (PFS), and disease-specific survival (DSS).

RESULTS

Sixty-one of 135 patients (45%) with adjuvant mitotane treatment had recurrences and 45/68 patients (66%) with mitotane treatment for advanced disease had progressive disease. After multivariate adjustment for sex, age, hormone secretion, tumor stage, and Ki67 index, RFS (hazard ratio [HR] = 1.07; 95% confidence interval [CI], 0.61-1.85; P = 0.82), and DSS (HR = 1.30; 95% CI, 0.58-2.93; P = 0.53) in adjuvantly treated ACC patients did not differ significantly between tumors with high and low SOAT1 expression. Similarly, in the advanced stage setting, PFS (HR = 1.34; 95% CI, 0.63-2.84; P = 0.45) and DSS (HR = 0.72; 95% CI, 0.31-1.70; P = 0.45) were comparable and response rates not significantly different.

CONCLUSIONS

SOAT1 expression was not correlated with clinical endpoints RFS, PFS, and DSS in ACC patients with mitotane monotherapy. Other factors appear to be relevant for mitotane treatment response and ACC patient survival.

Objective Response and Prolonged Disease Control of Advanced Adrenocortical Carcinoma with Cabozantinib

BACKGROUND

Objective response of advanced adrenocortical carcinoma (ACC) to mitotane and cytotoxic chemotherapy regimen is only ~20% and early tumor progression is frequent. Previous clinical trials with oral multikinase inhibitors were negative, which has been attributed in part to inadvertent drug interaction with mitotane. Cabozantinib (CABO) is an inhibitor of c-MET, vascular endothelial growth factor receptor 2, AXL, and RET and approved for advanced kidney cancer, liver carcinoma after previous sorafenib, and medullary thyroid carcinoma.

OBJECTIVE

To investigate the clinical efficacy and safety of CABO monotherapy in ACC patients.

DESIGN

Retrospective cohort study.

SETTING

Three referral centers for ACC (Germany, United States).

RESULTS

Sixteen patients (13 female) with progressive ACC received CABO after previous mitotane in 15/16 and 3 (median, range 0-8) further systemic treatments. Prior CABO therapy, mitotane was discontinued in all patients. Mitotane plasma concentration was <2 mg/L in 7/16 patients and discontinued >12 months in 6 additional patients before CABO use. In 4/5 cases with available plasma samples, CABO concentration was in the expected steady-state range. Adverse events of grade 1/2 and 3 were observed in 13 and 3 patients, respectively, and consistent with the known safety profile of CABO. Best response was partial response in 3, stable disease in 5, and progressive disease in 8 patients. Median progression-free and overall survival was 16 and 58 weeks, respectively.

CONCLUSION

CABO monotherapy appears to be safe and effective as a monotherapy in advanced ACC after failing prior treatments. Therefore, prospective investigation of CABO in ACC patients is warranted.

Objective response and prolonged stable disease in refractory adrenocortical carcinoma treated with cabozantinib: An international case series and protocols of phase II clinical trials

e16118

Background: Median overall survival (OS) in advanced adrenocortical (ACC) is only 12-15 months. Previous clinical trials with oral multi-kinase inhibitors (MKI) were negative likely due to inadvertent drug interaction with mitotane. Objective: To investigate the potential of cabozantinib (CABO) monotherapy in ACC patients. Methods: Retrospective cohort study at three referral centers for ACC (U.S. and Germany). Results: Fifteen patients (13 female) with progressive disease after mitotane (14/15 patients) and three (median; range 0-8) further systemic therapies were treated with 60 mg (20-140) CABO. Mitotane had been discontinued in all patients, in 11/15 patients mitotane was stopped > 270 days before CABO treatment or plasma concentration documented to be < 2 mg/L. Adverse events (AE) of grade 1/2 and 3 were observed in 12 and 2 patients, respectively and consistent with the known safety profile of CABO. Best response was partial response in 3, stable disease in 4 and progressive disease in 8 patients. Progression-free survival (PFS) of > 4 months (PFS4) was observed in 7 patients. Median PFS and OS was 12 and 41 weeks, respectively. Two single center phase II trials of CABO in advanced ACC in the U.S. (NCT03370718) and Germany (NCT03612232) will accrue 18 and 37 patients, respectively. Mitotane discontinuation and plasma concentrations < 2 mg/L are key inclusion criteria. The primary endpoint is PFS4. Conclusions: Cabozantinib monotherapy appears to be safe and active as a monotherapy in advanced ACC. Two parallel phase II trials will investigate CABO prospectively while controlling for drug interaction with mitotane.

SUN-350 Sterol-O-Acyl Transferase 1 Protein Expression Alone Is Not Sufficient to Predict Response to Mitotane Treatment in Adrenocortical Carcinoma

Background: Objective response rate to mitotane in advanced ACC is only ~20% and adverse drug effects are frequent and potentially serious. Markers of treatment response are not established. We have previously discovered that mitotane is an inhibitor of sterol-O-Acyl transferase 1 (SOAT1) which leads to depletion of cholesterol esters, endoplasmic reticulum stress and cell death in the ACC cell line NCI-H295. Data from a small cohort of patients with advanced ACC treated with mitotane monotherapy suggested longer progression-free survival in patients with high SOAT1 expression in ACC tissue. Aim: To investigate SOAT1 protein expression as a marker of treatment response to mitotane. Methods: SOAT1 protein expression was semiquantitatively determined by immunohistochemistry in full sections of 223 ACC treated with mitotane monotherapy in an adjuvant (n=151) and palliative setting (n=72) from eleven ENSAT centers. Expression was classified as high (H-score ≥2) and low (H-score <2) and correlated with recurrence-free (RFS) and progression-free survival (PFS), overall survival (OS), and mitotane levels after three and six months. Results: After multivariate adjustment for sex, ENSAT stage and Ki67 index, RFS (HR=1.3, log rank p=0.09) and OS (HR=1.6, log rank p=0.14) in adjuvantly treated ACC patients did not differ significantly between tumours with high and low SOAT1 expression. Similarly in the palliative setting, OS (HR=1.0, p=0.47) and PFS (HR=0.6, p=0.66) were not different. In line, high SOAT1 expression did not predict if patients reach the therapeutic window of mitotane. Conclusion: SOAT1 expression alone was not correlated with clinically significantly RFS, PFS, and OS in ACC patients neither in the adjuvant nor in the palliative setting.

Advanced Adrenocortical Carcinoma - What to do when First-Line Therapy Fails?

Adrenocortical carcinoma is a rare endocrine malignant disease with a generally unfavorable but heterogeneous prognosis. Although even in advanced stages a subset of patients experiences long-term disease stabilisation, effective systemic treatment options are limited. Mitotane is the only approved drug and the combination of etoposide, doxorubicin and cisplatin (plus mitotane) is currently considered as treatment standard for advanced adrenocortical carcinoma based on the results of a large randomized phase III trial. However, progression-free survival is often limited and further treatment options are frequently needed. Here we summarize the current knowledge about second and third-line therapeutic modalities (local and systemic) in advanced disease. Following the recent ESE-ENSAT guidelines local therapies play an important role for these patients. Regarding systemic therapies the best data are available for gemcitabine+capecitabine or streptozotocin (both with or without mitotane). Furthermore, we introduce our own approach to patients with advanced adrenocortical carcinoma based on our experience as a large multidisciplinary clinic dedicated to the care of patients with this orphan disease.

Treatment of Refractory Adrenocortical Carcinoma with Thalidomide: Analysis of 27 Patients from the European Network for the Study of Adrenal Tumours Registry

OBJECTIVE

Adrenocortical carcinoma (ACC) is a rare malignancy with a dismal prognosis. In advanced stages, tumour control by mitotane and cytotoxic chemotherapy is often temporary and salvage treatments are warranted.

METHODS

Retrospective cohort study of participants in the prospective European Networks for the Study of Adrenal Tumours (ENSAT) registry. Main outcome measures were best response during treatment, progression-free survival (PFS), both measured according to RECIST 1.1 by two blinded radiologists, and overall survival (OS).

RESULTS

Twenty-seven patients (13 males; median age 44.1 years) progressing after mitotane and a median of 4 further systemic treatments were included. Thalidomide was administered as tolerated with a starting dose of 50 mg and target dose of 200 mg /d. The median interval between treatment initiation and first imaging was 10.5 (4.4-17.5) weeks. The best response to treatment was stable disease (SD, n=2) and progressive disease (n=25), with a median PFS of 11.2 weeks and a median OS of 36.4 weeks. The first patient with SD discontinued treatment due to mild epistaxis and diarrhea after 22.3 weeks. The second patient had SD at the second treatment evaluation after 25.2 weeks and continued thalidomide but then had clinical progression and deceased after 54.3 weeks. In general, thalidomide induced only mild or moderate adverse effects (mainly fatigue and gastrointestinal complaints).

CONCLUSION

Thalidomide was overall well tolerated but resulted in disease control in only 2/27 (7.4%) patients. In the absence of predictive response markers, thalidomide should only be considered in exceptional cases as a salvage therapy in ACC.

Biochemical Diagnosis of Chromaffin Cell Tumors in Patients at High and Low Risk of Disease: Plasma versus Urinary Free or Deconjugated O-Methylated Catecholamine Metabolites

BACKGROUND

Measurements of plasma or urinary metanephrines are recommended for diagnosis of pheochromocytoma and paraganglioma (PPGL). What test offers optimal diagnostic accuracy for patients at high and low risk of disease, whether urinary free metanephrines offer advantages over deconjugated metanephrines, and what advantages are offered by including methoxytyramine in panels all remain unclear.

METHODS

A population of 2056 patients with suspected PPGLs underwent prospective screening for disease using mass spectrometric-based measurements of plasma free, urinary deconjugated, and urinary free metanephrines and methoxytyramine. PPGLs were confirmed in 236 patients and were excluded in others on follow-up evaluation.

RESULTS

Measurements of plasma free metabolites offered higher (P &lt; 0.01) diagnostic sensitivity (97.9%) than urinary free (93.4%) and deconjugated (92.9%) metabolites at identical specificities for plasma and urinary free metabolites (94.2%) but at a lower (P &lt; 0.005) specificity for deconjugated metabolites (92.1%). The addition of methoxytyramine offered little value for urinary panels but provided higher (P &lt; 0.005) diagnostic performance for plasma measurements than either urinary panel according to areas under ROC curves (0.991 vs 0.972 and 0.964). Diagnostic performance of urinary and plasma tests was similar for patients at low risk of disease, whereas plasma measurements were superior to both urinary panels for high-risk patients.

CONCLUSIONS

Diagnosis of PPGLs using plasma or urinary free metabolites provides advantages of fewer false-positive results compared with commonly measured deconjugated metabolites. The plasma panel offers better diagnostic performance than either urinary panel for patients at high risk of disease and, with appropriate preanalytics, provides the test of choice. Measurements of methoxytyramine in urine show limited diagnostic utility compared with plasma.

Enzyme autoinduction by mitotane supported by population pharmacokinetic modelling in a large cohort of adrenocortical carcinoma patients

OBJECTIVE

Mitotane is used for the treatment of adrenocortical carcinoma. High oral daily doses of typically 1- 6 g are required to attain therapeutic concentrations. The drug has a narrow therapeutic index and patient management is difficult because of a high volume of distribution, very long elimination half-life, and drug interaction through induction of metabolizing enzymes. The present evaluation aimed at the development of a population pharmacokinetic model of mitotane to facilitate therapeutic drug monitoring.

METHODS

Appropriate dosing information, plasma concentrations (1137 data points) and covariates were available from therapeutic drug monitoring (TDM) of 76 adrenocortical carcinoma patients treated with mitotane. Using nonlinear mixed effects modeling, a simple structural model was first developed, with subsequent introduction of metabolic autoinduction. Covariate data were analyzed to improve overall model predictability. Simulations were performed to assess the attainment of therapeutic concentrations with clinical dosing schedules.

RESULTS

A one-compartment pharmacokinetic model with first order absorption was found suitable to describe the data, with an estimated central volume of distribution of 6086 L related to a high interindividual variability of 81.5%. Increase in clearance of mitotane during treatment could be modeled by a linear enzyme autoinduction process. Body mass index was found to have an influence upon disposition kinetics of mitotane. Model simulations favor a high dose regimen to rapidly attain therapeutic concentrations, with the first TDM suggested on day 16 of treatment to avoid systemic toxicity.

CONCLUSION

The proposed model describes mitotane pharmacokinetics and can be used to facilitate therapy by predicting plasma concentrations.

Missed clinical clues in patients with pheochromocytoma/paraganglioma discovered by imaging

CONTEXT

Pheochromocytomas and paragangliomas (PPGLs) are rare but potentially harmful tumors that can vary in their clinical presentation. Tumors may be found due to signs and symptoms, as part of a hereditary syndrome or following an imaging procedure.

OBJECTIVE

To investigate potential differences in clinical presentation between PPGLs discovered by imaging (iPPGLs), symptomatic cases (sPPGLs) and those diagnosed during follow-up because of earlier disease/known hereditary mutations (fPPGL).

DESIGN

Prospective study protocol, which has enrolled patients from 6 European centers with confirmed PPGLs.

SETTING AND PATIENTS

Data were analyzed from 235 patients (37% iPPGLs, 36% sPPGLs, 27% fPPGLs) and compared for tumor volume, biochemical profile, mutation status, presence of metastases and self-reported symptoms.

RESULTS

iPPGL patients were diagnosed at a significantly higher age than fPPGLs (p<0.001), found to have larger tumors (p=0.003) and higher metanephrine and normetanephrine levels at diagnosis (p=0.021). Significantly lower than in sPPGL, there was a relevant number of self-reported symptoms in iPPGL (2.9 vs. 4.3 symptoms, p<0.001). In 16.2% of iPPGL, mutations in susceptibility genes were detected, although this proportion was lower than in fPPGL (60.9%) and sPPGL (21.5%).

CONCLUSIONS

Patients with PPGLs detected by imaging were older, have higher tumor volume and more excessive hormonal secretion in comparison to those found as part of a surveillance program. Presence of typical symptoms indicates that in a relevant proportion of those patients the PPGL diagnosis had been delayed. Précis: Pheochromocytoma/paraganglioma discovered by imaging are often symptomatic and carry a significant proportion of germline mutations in susceptibility genes.

Mitotane Monotherapy in Patients With Advanced Adrenocortical Carcinoma

CONTEXT

Although mitotane is the only approved drug for the treatment of adrenocortical carcinoma (ACC), data on monotherapy in advanced disease are still scarce.

OBJECTIVE

To assess the efficacy of mitotane in advanced ACC in a contemporary setting and to identify predictive factors.

DESIGN AND SETTING

Multicenter cohort study of three German referral centers.

PATIENTS

One hundred twenty-seven patients with advanced ACC treated with mitotane monotherapy.

OUTCOME MEASURES

Response Evaluation Criteria in Solid Tumors evaluation, progression-free survival (PFS) and overall survival (OS) by Kaplan-Meier method, and predictive factors by Cox regression.

RESULTS

Twenty-six patients (20.5%) experienced objective response, including three with complete remission. Overall, median PFS was 4.1 months (range 1.0 to 73) and median OS 18.5 months (range 1.3 to 220). Multivariate analysis indicated two main predictive factors: low tumor burden (<10 tumoral lesions), hazard ratio (HR) for progression of 0.51 (P = 0.002) and for death of 0.59 (P = 0.017); and initiation of mitotane at delayed advanced recurrence, HR 0.35(P < 0.001) and 0.34 (P < 0.001), respectively. Accordingly, 67% of patients with low tumor burden and mitotane initiation ≥360 days after primary diagnosis experienced a clinical benefit (stable disease >180 days). Patients who achieved mitotane levels >14 mg/L had significantly longer OS (HR 0.42; P = 0.003).

CONCLUSIONS

At 20.5% the objective response rate was slightly lower than previously reported. However, >20% of patients experienced long-term disease control at >1 year. In general, patients with late diagnosis of advanced disease and low tumor burden might especially benefit from mitotane monotherapy, whereas patients with early advanced disease and high tumor burden are probably better candidates for combined therapy of mitotane and cytotoxic drugs.

[Pheochromocytoma - Current Recommendations on Diagnostics, Therapy and Follow-up]

Laborchemische Diagnostik Die Bestimmung der Metanephrine (Überbegriff für Normetanephrin und Metanephrin) im Plasma oder der fraktionierten Metanephrine im 24h-Sammelurin sind Diagnostik der ersten Wahl und haben die Bestimmung von Adrenalin und Noradrenalin bzw. Vanillinmandelsäure endgültig abgelöst. Werte > 3fach der oberen Norm werden als diagnostisch angesehen. Bei leicht bis moderat erhöhten Befunden empfiehlt sich weitere Bestätigungsdiagnostik.

Bildgebende Diagnostik Computertomografie (CT) und Magnetresonanztherapie (MRT) sind ebenbürtige Optionen. Eine funktionelle Bildgebung ist nach den neuen Leitlinien nur bei Malignitätsverdacht bzw. metastasierten Phäochromozytomen oder zur Detektion von Paragangliomen zwingend.

Genetische Diagnostik Bei mind. 30 % der Patienten mit Phäochromozytom lässt sich eine genetische Disposition feststellen. Inzwischen wurden 14 „Phäochromozytom-Paragangliom-Gene“ identifiziert. Daher wird grundsätzlich jedem Patienten eine genetische Aufklärung und Diagnostik angeboten.

Therapie Hier geht die Empfehlung zur minimalinvasiven Resektion, sofern dies technisch möglich ist und kein Malignitätsverdacht besteht. Alle Patienten mit hormonell aktivem Phäochromozytom sollten eine präoperative α-Blockade für 7 – 14 Tage erhalten.

Nachsorge Alle Patienten bedürfen einer regelmäßigen jährlichen Nachsorge für mindestens 10 Jahre. Bei nachgewiesener Mutation, großem Tumor oder jungem Patientenalter wird lebenslängliche Nachsorge empfohlen.