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.

Prevalence and clinical correlations of SF3B1 variants in lactotroph tumours

OBJECTIVE

A somatic mutational hotspot in the SF3B1 gene was reported in lactotroph tumours. The aim of our study was to examine the prevalence of driver SF3B1 variants in a multicentre independent cohort of patients with lactotroph tumours and correlate with clinical data.

DESIGN AND METHODS

This was a retrospective, multicentre study involving 282 patients with lactotroph tumours (including 6 metastatic lactotroph tumours) from 8 European centres. We screened SF3B1 exon 14 hotspot for somatic variants using Sanger sequencing and correlated with clinicopathological data.

RESULTS

We detected SF3B1 variants in seven patients with lactotroph tumours: c.1874G > A (p.Arg625His) (n = 4, 3 of which metastatic) and a previously undescribed in pituitary tumours variant c.1873C > T (p.Arg625Cys) (n = 3 aggressive pituitary tumours). In two metastatic lactotroph tumours with tissue available, the variant was detected in both primary tumour and metastasis. The overall prevalence of likely pathogenic SF3B1 variants in lactotroph tumours was 2.5%, but when we considered only metastatic cases, it reached the 50%. SF3B1 variants correlated with significantly larger tumour size; higher Ki67 proliferation index; multiple treatments, including radiotherapy and chemotherapy; increased disease-specific death; and shorter postoperative survival.

CONCLUSIONS

SF3B1 variants are uncommon in lactotroph tumours but may be frequent in metastatic lactotroph tumours. When present, they associate with aggressive tumour behaviour and worse clinical outcome.

Transplantable human thyroid organoids generated from embryonic stem cells to rescue hypothyroidism

The thyroid gland captures iodide in order to synthesize hormones that act on almost all tissues and are essential for normal growth and metabolism. Low plasma levels of thyroid hormones lead to hypothyroidism, which is one of the most common disorder in humans and is not always satisfactorily treated by lifelong hormone replacement. Therefore, in addition to the lack of in vitro tractable models to study human thyroid development, differentiation and maturation, functional human thyroid organoids could pave the way to explore new therapeutic approaches. Here we report the generation of transplantable thyroid organoids derived from human embryonic stem cells capable of restoring plasma thyroid hormone in athyreotic mice as a proof of concept for future therapeutic development.

Results of the ADIUVO Study, the First Randomized Trial on Adjuvant Mitotane in Adrenocortical Carcinoma Patients

Background: The ESE-ENSAT guidelines on the management of adrenocortical carcinoma (ACC) suggest adjuvant mitotane for patients at high risk of recurrence following radical surgery. This indication has a limited evidence base, lacking results from randomized controlled trials. No suggestion for or against adjuvant mitotane in low-risk patients was given, since studies did not stratify patients for prognosis. The randomized controlled study ADIUVO compared the efficacy of adjuvant mitotane treatment vs. observation in prolonging recurrence-free survival (RFS) in ACC patients at low-intermediate risk of recurrence.

Methods: The main inclusion criteria were: stage I-III ACC, R0 surgery, and Ki-67 ≤10%. Patients were randomly assigned 1:1 to adjuvant mitotane (MIT) or observation (OBS). The primary endpoint of the study was RFS. Patients who refused randomization were offered inclusion in the ADIUVO OBSERVATIONAL study. In this prospective, observational study, patients were managed as in the ADIUVO study. A total of 91 patients were enrolled in ADIUVO, 45 in the MIT and 46 in the OBS arm. Baseline characteristics of patients were perfectly matched between the 2 arms: median age, 51 vs. 50.5 years; female, 73% vs. 67%; stage I, 20% vs. 26%; stage II, 67% vs. 63%, stage III, 13% vs. 11%; ACC secretion 44% vs. 36%; Weiss 5 vs. 5; respectively. In ADIUVO OBSERVATIONAL, 42 patients were treated with mitotane and 53 were untreated. Baseline characteristics of patients were matched between the 2 groups and with MIT and OBS groups in ADIUVO. Thus, the ADIUVO OBSERVATIONAL cohorts could be analyzed in parallel to those of ADIUVO.

Results: In the ADIUVO study, recurrences were 8 in the MIT and 11 in the OBS arm, while deaths were 2 and 5, respectively. RFS and overall survival (OS) did not significantly differ between the 2 arms. Tumor size was a predictor of RFS in multivariable analysis. In the OBS arm, the HR for recurrence was 1.321 (95%CI, 0.55–3.32, p=0.54) and HR for death 2.171 (95%CI, 0.52–12.12, p=0.29). The survival analysis in the ADIUVO OBSERVATIONAL study confirmed the findings of ADIUVO. Given the outcome of both studies, the NNT is 55.

Conclusions: ACC patients at low-intermediate risk of recurrence after surgery are a minority; however, they show a far better prognosis than expected (5-year RFS is about 75%) and do not benefit significantly from adjuvant mitotane. The results of the ADIUVO study do not support routine use of adjuvant mitotane in this subset of patients, who may thus avoid a potentially toxic treatment. This is an important step toward personalization of ACC care.

cfDNA in pancreatic neuroendocrine carcinoma management with Cushing's syndrome

Summary

We report a case of metastatic pancreatic neuroendocrine carcinoma associated with paraneoplastic Cushing's syndrome, successively treated with five lines of treatment (platin-etoposide, LV5FU2-dacarbazine, FOLFIRINOX, pembrolizumab, and paclitaxel) and anti-secretory treatment. Circulating-free DNA (cfDNA) was analysed at each morphological evaluation starting from the second-line treatment. cfDNA changes were well correlated with the disease course, and cfDNA may be used as a predictive marker and/or as an early marker of response. In addition, the absolute count of atypical cells was elevated upon disease progression.

Learning points

cfDNA changes were well correlated with the Cushing's syndrome course and with the tumour burden changes assessed by laboratory markers and by RECIST criteria.cfDNA analysis was used to determine the pharmacogenetic patterns of the present patient.An elevated number of atypical circulating cells was noticed upon disease progression.

Age- and Sex-Specific TSH Upper-Limit Reference Intervals in the General French Population: There Is a Need to Adjust Our Actual Practices

It is well known that thyroid dysfunction increases with age. This study is aimed to determine reference intervals, in males and females, suitable for thyroid disease exploration during adult life using routinely collected serum thyrotropin (TSH) data in a tertiary center from 2007 to 2018. Over 11 years, 295,775 TSH levels were measured in a single lab. Among the 156,025 TSH results available for analysis, 90,538 values were from female subjects, 82,019 were from patients aged >60 years and 26,825 were from patients aged >80 years. By using an indirect approach, we determined reference values of TSH adapted to age and sex, and we then evaluated the proportion of patients who would have been reclassified with these reference values. The median TSH ranged from 1.2–1.4 mUI/L during the study period. The upper limit of reference range of TSH increased with age; in females the median to 97.5th percentile values increased continuously from the age of 30 years to the oldest age group. Using new calculated reference values in patients with TSH above the conventional upper-limit reference value (4 mUI/L), the proportion of results reclassified as within the reference interval among patients aged >60 years ranged, according to age group, from 50.5% to 65.1% of females and from 33.0% to 37.7% of males. The use of TSH age-specific and sex-specific upper-limit reference values led to the reclassification of a great number of samples, notably among women. This suggests that age-specific TSH upper-limit reference intervals in daily practice should be used in order to avoid misclassification.

Effect of Buparlisib, a Pan-Class I PI3K Inhibitor, in Refractory Follicular and Poorly Differentiated Thyroid Cancer

BACKGROUND

Dysregulation of the phosphatidylinositol 3-kinase (PI3K) pathway is frequent in advanced follicular (FTC) and poorly differentiated thyroid (PDTC) carcinomas and has been implicated in oncogenesis and tumor progression. This study investigated the efficacy and safety of buparlisib, a pan-PI3K inhibitor in radioiodine refractory FTC and PDTC.

METHODS

The primary endpoint of this open-label, multicenter, phase 2 pilot study was progression-free survival (PFS) at 6 months. The sample size was determined considering that a PFS ≤50% at 6 months would denote an absence of benefits (null hypothesis). Secondary endpoints were objective response rate, PFS at 12 months, overall survival at 6 and 12 months, and safety based on the frequency and severity of adverse events (AEs).

RESULTS

Forty-three patients (19M/24 F; median age: 67 years) with metastatic, radioiodine refractory, progressive disease received buparlisib, 100 mg, daily. Histology was PDTC in 25 (58%), FTC in 17 (40%), and Hürthle cell carcinoma in 1 (2%). RAS mutation was found in 44% (12/27) and activation of the PI3K pathway in 35% (8/23) of tested tumors. The probability of PFS was 41.7% [95% confidence interval (CI) 7.7-55.5] at 6 months and 20.9% [CI 0-35.7] at 12 months, lower than the 50% expected PFS. At 6 months, 25.6% patients had stable disease, 48.8% were progressive and 25.6% had stopped treatment due to AE. The response to therapy was not influenced by age, sex, histology, or genetic alterations. The overall survivals at 6 and 12 months were 85.9% [CI 76-97] and 78.7 % [CI 67-92], respectively. The mean tumor growth rate decreased from 3.78 mm/month [CI 2.61-4.95] before treatment to 0.8 mm/month [CI -0.2-1.88] during treatment (p < 0.02). Severe grade 3-4 AEs occurred in 27 patients (63%), including hepatitis (25%), hyperglycemia (21%), mood disorders (12%), and skin toxicity (12%), with favorable outcome after temporary or permanent treatment discontinuation or dose reduction.

CONCLUSIONS

Buparlisib did not result in significant efficacy in advanced FTC and PDTC. However, the decrease in tumor growth rate may suggest incomplete inhibition of oncogenic pathways and/or escape mechanisms. This should lead to evaluate combined therapy associating inhibitors of both the PI3K and mitogen-activated protein kinase pathways.