Received: 1 October 2020

Revised: 27 October 2020

Accepted: 14 November 2020

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Pediatric Blood & Cancer

SOCIÉTÉ INTERNATIONALE D’ONCOLOGIE PÉDIATRIQUE

aspho The American Society of Pediatric Hematology/Oncology

INTERNATIONAL SOCIETY OF PAEDIATRIC ONCOLOGY

Clinical prognostic factors in pediatric adrenocortical tumors: A meta-analysis

Elisa Zambaiti1 İD Miriam Duci1 Federica De Corti1 Piergiorgio Gamba1

Patrizia Dall’Igna2 1D

Filippo Ghidini1 Calogero Virgone1 İD

1 Department of Women’s and Children’s Health, University Hospital of Padua, Padua, Italy

2 Department of Emergencies and Organ Transplantation, Azienda Ospedaliero-Universitaria Consorziale Ospedale Pediatrico Giovanni XXIII, Bari, Italy

Correspondence

Calogero Virgone, Department of Women’s and Children’s Health, University Hospital of Padua, Via Giustiniani 3, 35128 Padua, Italy. Email: calogero.virgone@unipd.it

Abstract

Pediatric adrenocortical tumors (ACT) are rare and sometimes aggressive malignan- cies, but there is no consensus on the outcome predictors in children. A systematic search of MEDLINE, SCOPUS, Web of Science, and the Cochrane Library for studies from 1994 to 2020 about pediatric ACT was performed. In 42 studies, 1006 patients, aged 0-18 years, were included. The meta-analyses resulted in the following predictors of better outcome: age <4 years (P <. 00001), nonsecreting tumors (P =. 004), complete surgical resection (P <. 00001), tumor volume (P <. 0001), tumor weight (P <. 00001), tumor maximum diameter (P = . 0009), and Stage I disease (P < . 00001). Moreover, patients affected by Cushing syndrome showed a worse outcome (P < . 0001). Inter- national prospective studies should be implemented to standardize clinical prognostic factors evaluation, together with pathological scores, in the stratification of pediatric ACT.

KEYWORDS

adrenocortical carcinoma, adrenocortical tumors, children, meta-analysis, prognosis study, prog- nostic factors, systematic review

1 INTRODUCTION

Pediatric adrenocortical tumors (ACTs) are rare and sometimes aggres- sive endocrine malignancies, frequently associated with Li-Fraumeni syndrome, a familial cancer predisposition disorder caused by germline mutations in the tumor suppressor gene TP53, and account for approx- imately 0.38% of all childhood cancer cases.1 ACT develop from the adrenal cortex, with an estimated incidence of one per million each year, and comprise benign adrenocortical adenomas (ACA) and highly malignant adrenocortical carcinomas (ACC), whose pathogenesis is incompletely understood. Patients with ACC generally have a poor clinical outcome, because there is no effective therapy for advanced and metastatic forms, accounting for a 5-year overall survival of less than 40%.2 On the other hand, ACA is associated with excellent prog- nosis, but only about 20% of pediatric ACTs are classified as ACA.

As a matter of fact, children with ACC seem to have a better out- come when compared with adults, and some authors attributed this finding to an overestimation of malignancy based on the use of adult scores, which may be not fully applicable to the pediatric population.3,4 The Wieneke index has been reported to have a prognostic value more reliable in comparison with adult scores,5,6 and lately the five- item score7 was described to be useful when stratifying patients with ACT.

In this scenario, it is still difficult to establish which patients may benefit from a more aggressive medical approach after surgery, and the use of pediatric pathology scores could be a valid option if considered together with clinical risk factors, as it happens in the management of other pediatric tumors as neuroblastoma or rhabdomyosarcoma.

In the past, various clinical features were variably reported to asso- ciate with a poor outcome: age >4 years, volume, weight, size, Cushing syndrome, R1 resections, initial biopsy, and stage are the clinical fea- tures more commonly taken into account to define risk stratification.8,9

Unfortunately, there is no consensus on which clinical features may be determinant to predict the outcome in pediatric ACT, as most of the features described above did correlate with prognosis in a univariate analysis but were not confirmed at the multivariate analysis.8

2 METHODS

This review was performed according to an a priori designed protocol and recommended for systematic reviews and meta-analysis.10-12

MEDLINE, SCOPUS, Web of Science, and the Cochrane Library, including the Cochrane Database of Systematic Reviews (CDSR), Database of Abstracts of Reviews of Effects (DARE), and the Cochrane Central Register of Controlled Trials (CENTRAL), were searched elec- tronically in April 2020 utilizing combinations of relevant medical subject heading (MeSH) terms, keywords, and word variants for “adrenocortical tumors,” “adrenocortical adenoma,” “adrenocortical carcinoma,” “prognostic factors,” and “children” (Supporting Informa- tion S1). The search and selection criteria were restricted to English language. Reference lists of relevant articles and reviews were manu- ally searched for additional reports. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA-P) guidelines13 were followed.

The study was registered with the PROSPERO database (registra- tion number CRD42020180970).

2.2 Study selection, data collection, and data items

Studies were assessed according to the following criteria: population, outcome, clinical features, and tumor features. Inclusion criteria were: studies reporting pediatric cases of ACTs with available data on treatment, histology, and follow up; publication span including the last 25 years (1994-2020). Four authors, divided in two groups (Filippo Ghidini, Calogero Virgone and Elisa Zambaiti, Miriam Duci) reviewed all abstracts independently. Agreement about potential relevance was reached by consensus, and full-text copies of those articles were obtained. The same reviewers independently extracted relevant data regarding study characteristics and ACT features and outcomes. Case reports or case series without outcome data and/or clinical data were excluded. Inconsistencies were discussed by the reviewers and consensus reached. If more than one study was published for the same cohort with identical end points, the report containing the most comprehensive information on the population was included to avoid overlapping populations. For those articles in which information was not reported but the methodology was such that this information would have been recorded initially, the authors were contacted. Quality assessment of the included studies was performed using the Newcastle-Ottawa Scale for cohort studies (Supporting Information S2).14

2.3 Summary measures, synthesis of the results, and risk of bias

The clinical prognostic factors analyzed in this review were age, sex, tumor secreting status, tumor volume, tumor weight, tumor maxi- mum diameter, surgical results, and stage. Age greater than or less than 4 years was considered according to previous reports, which showed that children under 4 years of age usually show a favorable outcome. Indeed, distant metastases are observed at a higher rate in adolescents.7,8

Secretion pattern has been sporadically reported to associate with outcome: Cushing syndrome and nonsecreting tumors were reported to have worse prognosis.2

Cut-off values for tumor volume (200 cm3), for tumor weight (100 or 400 g), and for tumor maximum diameter (<5 cm, between 5 and 10 cm, >10 cm) were established in previous literature data.1,8,9 Although size in the ACT literature has been described with different units of mea- surement, the evidence that larger tumors may present a dismal out- come at higher rates is widely recognized.

Surgical results were defined as complete resection or incom- plete resection (microscopic or macroscopic residuals) in patients who underwent surgery on the primary tumor. A complete resection at diagnosis is considered to be a major prognostic factor, since ACTs are localized in greater part. Stage was assessed on the basis of COG staging system for ACT proposed by Sandrini et al15 and later mod- ified by Michalkiewicz et al2 and Ribeiro et al,1 as it represents the most currently used worldwide: studies in which stage assessment was performed with different systems were not included into this analysis.

The outcome analyzed in this systematic review was the reported patient’s status (alive or dead).

2.4 Statistical analysis

Overall, we evaluated separately the association between eight clinical prognostic factors and the outcome for a total of 17 separated meta- analyses.

Data were analyzed by using Review Manager (RevMan, Version 5.3, Cochrane Collaboration). For categorical variables risk ratio (RR) with 95% confidence intervals (CIs) were generated. We performed descriptive statistics, and calculated the pooled RR and 95% CI for each prognostic factor that was studied in more than one different study. The RRs were pooled using the fixed-effects model. The hetero- geneity was assessed by the chi-square test and quantified using the /2 statistic. The I 2 statistic represents the percentage of between-study variation that is due to heterogeneity rather than chance: a value of 0% indicates no observed heterogeneity, whereas I 2 values of ≥50% indicate a substantial level of heterogeneity. A fixed-effects model was used if substantial statistical heterogeneity was not present. Publication bias was examined by funnel plot analysis. A P-value of less than .05 was considered statistically significant.

FIGURE 1 Flowchart summarizing inclusion of studies in the systematic review

2226 papers found

Scopus: 1219

PubMed: 376

Web of Science: 631

Manual search: 7

Total (minus overlap): 1895

Rejected on Tital/Abstract: 1620

· case reports

· review of the literature

· age > 18 years

· clinical data/outcome not available

Full Text found: 275

Rejected on Full Text: 233

· case reports

· review of the literature

· age > 18 years

· clinical data/outcome not available

· mixed population

· raw data not available

· overlapping series

Accepted studies: 42 (1006 patients)

3 RESULTS

A total of 2233 articles were identified and 275 were assessed with respect to their eligibility for inclusion. Forty-two studies were included in the systematic review (Figure 1), accounting for a total of 1006 pediatric patients with diagnosis of an ACT. The general charac- teristics of the studies included in the systematic review are reported in Table 1.

Quality assessment of the included studies was performed using Newcastle-Ottawa Scale for cohort studies. Almost all the included studies showed an overall good rate with regard to the selection and comparability of the study groups and to the ascertainment outcome of interest (Supporting Information S2). The major weaknesses of these studies were represented by their retrospective design, a lack of homo- geneity of the clinical features evaluated, and the different thresholds adopted to define clinical features (as age, tumor volume, weight, max- imum diameter, and stage).

3.1 Age

Thirty-three papers entered this meta-analysis.2,5,16-45 An age of more than 4 years was found to have RR of 3.07 (P < . 00001; 95% CI 2.35- 4.02; I 2 0%) (Figure 2).

3.2 | S Sex

Thirty-six papers2,5,16-18,20-47,49,50 allowed the evaluation of gender effect on outcome: females were found to have RR of 1.21, without reaching a significance (P = . 14; 95% CI 0.94-1.55; /2 0%).

3.3 Tumor secreting status

Three different meta-analyses were performed in order to deter- mine the effect of secretion pattern on outcome. Firstly, the patients affected by Cushing syndrome versus those without Cushing syndrome were compared (Figure 3A). Twenty-seven studies2,5,16-19,23,24,26,29-34,36-41,43,45,46,48,51 assessed the outcomes between these two groups, and being affected by Cushing syndrome resulted in a worse outcome (P < . 0001; RR 1.88; 95% CI 1.38-2.58; [2 6%). Secondly, 19 studies5,18,20,26,30-33,36-38,40,41,43,45,46,49,51 com- pared the secreting tumors and nonsecreting masses, identifying hormonal secretion as a negative prognostic factor (P = . 004; RR 1.63; 95% CI 1.17-2.27; I 2 0%). Finally, the comparison between patients affected by Cushing syndrome and nonsecreting tumors was performed in 17 studies5,18,20,26,30-33,37,38,40,41,43,45,46,49,51 and no difference in outcome was found (P = . 40; RR 1.19; 95% CI 0.79-1.79; I 2 0%) (Figure 3B).

3.4 Tumor volume

Five papers reported tumor volume.5,18,20,30,31 The meta-analysis (Supporting Information S3) showed a worse outcome for the tumors more than 200 cm3 of volume (P <. 0001; RR 3.37; 95% CI 1.93-5.88; /2 60%).

3.5 Tumor weight

Tumor weight was reported in 15 studies. Two meta-analyses were performed for the two different cutoffs. Either tumors weighing more than 400 g17-21,27,31,33,35,37-40,42,52 or tumors weighing more than 100 g17,18,20,21,31,33-35,37-40,42,45,52 were considered as risk factor for a worse outcome (respectively, P <. 00001; RR 4.29; 95% CI 3.19-5.78; I 2 0% and P < .00001; RR 5.46; 95% CI 3.24-9.20; I 2 0%) (Figure 4A,B).

3.6 Tumor maximum diameter

Three different meta-analyses were performed, considering tumor maximum diameter as a risk factor. The different groups were com- pared as follows. First, tumors <5 cm versus tumors >5 and <10 cm were included in 11 studies,5,25,29,32-35,37,42,45,52 showing a worse outcome for the tumors >5 and <10 cm (P = . 008; RR 2.85; 95% CI 1.31-6.17; I 2 0%). Second, tumors <5 cm versus tumors >5 cm were included in 15 studies,5,19,22,23,25,28,29,32-35,37,42,45,52 resulting

TABLE 1 General characteristics of the included studies
Author, year (location)Study designSample sizePeriodM;FMean age at diagnosis (years)Number of deathsMean follow-up years (range)
Federici, 1994 (Italy)Cohort121976-19895;75.026.4 (1.5-14)
Damiani, 1995 (Brazil)Cohort331975-199311;223.7176.7 (0-20)
Bergadà, 1996 (Argentina)Cohort201970-19915;157.1210 (0-23)
Mendonca, 1996 (Brazil)Cohort181980-19925;133.125.1 (0.5-9.5)
Michalkiewicz, 1997 (USA, Brazil, Canada, Uruguay, Norway, Chile)Cohort201988-199418;12.012.5 (0.1-6.2)
Mayer, 1997 (Canada)Cohort111972-19963;87.015.6 (0.8-15)
Driver, 1998 (UK)Cohort181954-19953;155.6124.3 (0.1-26)
Teinturier, 1999 (France)Cohort541973-199327;274.0283.2 (0.1-20)
Wolthers, 1999 (UK)Cohort301976-19967;234.943.8 (0.4-75)
Wilkin, 2000 (Canada)Cohort10-2;85.717.5 (0.5-18)
Mishra, 2001 (India)Cohort101990-19994;67.452.2 (0-7.6)
Misu, 2001 (Japan)Cohort4-3;12.515.9 (3.0-12)
Ciftici, 2001 (Turkey)Cohort301970-199911;196.7112.5
Latronico, 2001 (Brazil)Cohort18-5;132.215.3 (0.2-13)
McDonnell, 2003 (Australia)Cohort121976-20016;62.5310 (1.0-25.8)
Narasismhan, 2003 (India)Cohort81989-20002;62.522.3 (0.5-5.0)
Sandrini, 2005 (Brazil)Cohort21-7;143.748.6 (0.3-19)
Figuereido, 2005 (Brazil)Cohort9-3;62.62-
Barbosa, 2004 (Brazil)Cohort7-4;35.115.8 (1.2-8.2)
Pinto, 2005 (Brazil)Cohort16-6;104.414.4 (1.0-10)
Rosati, 2008 (Brazil)Cohort12-3;93.656.6 (2.4-15.8)
Loncarevic, 2008 (Germany)Cohort141998-20076;83.864.4 (4.3-9.8)
Lorea, 2012 (Brazil)Cohort601991-200915;453.4105.7 (0.7-14)
Waldmann, 2012 (Germany)Cohort2-1;11614.2 (1.9-6.5)
Fragoso, 2012 (Brazil)Cohort241990-20107;173.856.7 (0.6-14)
Custodio, 2013 (Brazil)Cohort192005-20104;151.543.8 (2.0-5.8)
Borges, 2013 (Brazil)Cohort571991-200914;433.4105.2 (0-14)
Wendt, 2014 (USA)Cohort51975-20113;23.137.6 (0.5-32)
Nazli Gonç, 2014 (Turkey)Cohort181999-20138;105.766.0 (1.0-11)
Kerkhofs, 2014 (The Netherlands)Cohort121989-20133;94.156.4 (0.1-14.8)
Dall'Igna, 2014 (Italy)Cohort581982-201119;395.1125.9 (0.2-9.9)
Sakoda, 2014 (UK)Cohort291987-201114;152.2102.1 (0.1-15)
Chatterjee, 2015 (India)Cohort132005-20144;92.932.2
Das, 2016 (India)Cohort142005-20155;92.134.1 (0.5-5)
Bulzico, 2016 (Brazil)Cohort271997-20158;195.1102.3 (0.1-12.8)
Pinto, 2017 (USA)Cohort592006-201317;423.3144.0 (0-23)
Picard, 2018 (France)Cohort952000-201828;675.0165.3 (0.2-17)
Jehangir, 2019 (India, Australia)Cohort222006-201612;106.326.0 (2.1-6.7)
Monteiro, 2019 (Brazil)Cohort122004-20152;102.014.5 (0.4-11)
Parise, 2019 (Brazil)Cohort48-18;302.8157.0 (0.2-21)
Zekri, 2020 (Egypt)Cohort182007-20166;124.083.2
Pinto, 2020 (USA)Cohort11-3;84.53-
Study or Subgrouplog[Risk Ratio]SEWeightRisk Ratio IV, Fixed, 95% CIRisk Ratio IV, Fixed, 95% CI
Barbosa 20041.32181.48880.8%3.75 [0.20, 69.39]
Bergada 1996-0.40551.33851.0%0.67 [0.05, 9.19]
Borges 20131.62470.5635.9%5.08 [1.68, 15.30]
Chatterjee 20151.19390.68983.9%3.30 [0.85, 12.75]
Custodio 20131.4040.63234.7%4.07 [1.18, 14.06]
Dall'Igna 20141.40180.72823.5%4.06 [0.97, 16.93]
Damiani 19951.09860.376113.3%3.00 [1.44, 6.27]
Das 201601.30931.1%1.00 [0.08, 13.02]
Federici 19942.19721.39161.0%9.00 [0.59, 137.65]
Figuereido 2004-0.5390.72373.6%0.58 [0.14, 2.41]
Fragoso 20121.89711.03551.8%6.67 [0.88, 50.74]
Gonc 20140.69310.72653.6%2.00 [0.48, 8.31]
Jehangir 2019-0.36771.34611.0%0.69 [0.05, 9.69]
Kerkhofs 20142.68561.37481.0%14.67 [0.99, 217.06]
Latronico 20013.29581.4530.9%27.00 [1.57, 465.74]
Lonarevic 20080.28770.61245.0%1.33 [0.40, 4.43]
Lorea 20121.62470.5635.9%5.08 [1.68, 15.30]
Mayer 1997-0.62861.53030.8%0.53 [0.03, 10.71]
McDonnell 20031.02961.07571.6%2.80 [0.34, 23.06]
Mendonca 19951.25281.29561.1%3.50 [0.28, 44.35]
Michalkiewicz 19971.2041.45490.9%3.33 [0.19, 57.72]
Mishra 20012.06141.35611.0%7.86 [0.55, 112.09]
Monteiro 20191.68641.53480.8%5.40 [0.27, 109.35]
Narasismhan 20031.09861.15471.4%3.00 [0.31, 28.84]
Parise 20191.23210.395912.0%3.43 [1.58, 7.45]
Pinto 20052.05411.54590.8%7.80 [0.38, 161.42]
Pinto 20173.53161.41530.9%34.18 [2.13, 547.60]
Rosati 20081.17560.55786.0%3.24 [1.09, 9.67]
Sakoda 20142.02810.68734.0%7.60 [1.98, 29.23]
Sandrini 20042.63911.42820.9%14.00 [0.85, 230.06]
Wendt 20140.28770.81652.8%1.33 [0.27,6.61]
Wilkin 2000-1.09861.52750.8%0.33 [0.02, 6.65]
Zekri 20190.51080.55786.0%1.67 [0.56, 4.97]
Total (95% CI)100.0%3.07 [2.35, 4.02]
Heterogeneity: Chiz= 29.91, df = 32 (P = 0.57); 12= 0% Test for overall effect: Z = 8.20 (P < 0.00001)0.0020.1 1 10
Favours[> 4 years] Favours [< 4 years]

500

FIGURE 2 Forest plot showing risk ratio (RR) according to age (<4 years vs >4 years) for each study and pooled for all studies. Only first author of each study is given
aWeightRisk Ratio IV, Fixed, 95% CIRisk Ratio IV, Fixed, 95% CI
Study or Subgrouplog[Risk Ratio)SE
Barbosa 2004-0.60610.59037.4%0.55 [0.17. 1.73]
Bergada 19961.42711.48881.2%4.17 [0.23. 77.10]
Borges 20131.09860.57747.7%3.00 [0.97. 9.30]
Ciftici 20010.36770.65046.1%1.44 [0.40, 5.17]
Custodio 2013-0.55961.36711.4%0.57 [0.04. 8.33]
Dalligna 20141.32180.63576.4%3.75 [1.08. 13.04]
Federici 19940.69311.27481.6%2.00 [0.16. 24.33]
Figuereido 20040.22311.2451.7%1.25 [0.11, 14.34]
Gonc 2014-0.40550.76384.4%0.67 [0.15, 2.98]
Latronico 20011.09861.57061.0%3.00 [0.14. 65.16]
Lonarevic 2008-1.50411.35911.4%0.22 [0.02. 3.19]
Lorea 20121.64790.406815.6%5.20 [2.34. 11.53]
Mayer 19971.65821.50791.1%5.25 [0.27, 100.85]
McDonnell 2003-0.40551.4721.2%0.67 [0.04. 11.94]
Mendonca 19952.45671.47031.2%11.67 [0.65, 208.19]
Michalkiewicz 19971.65821.57171.0%5.25 [0.24, 114.28]
Misu 20011.09861.41421.3%3.00 [0.19. 47.96]
Monteiro 20190.62861.53031.1%0.53 [0.03. 10.71]
Narasismhan 2003-0.28771.19021.8%0.75 [0.07. 7.73]
Parise 2019.0.23460.55498.4%0.79 [0.27. 2.35]
Pinto 20050.40551.55461.1%1.50 [0.07. 31.58]
Pinto 20170.8210.64396.2%2.27 [0.64. 8.03]
Pinto 20201.38631.17261.9%4.00 [0.40. 39.83]
Rosati 20080.18230.54778.6%1.20 [0.41, 3.51]
Sandrini 20040.33651.10842.1%1.40 (0.16. 12.29]
Wilkin 20002.07941.4861.2%8.00 [0.43, 147.22]
Zekri 20191.04980.65746.0%2.86 [0.79. 10.36]
Total (95% CI)100.0%1.88 [1.38, 2.58]
Heterogeneity: Chi= 27.56, df= 26 (P = 0.38); P= 6%0.0050.1 1 10
Test for overall effectZ = 3.95 (P < 0.0001)Favours [Cushing] Favours [No Cushing]
blog[Risk Ratio]SEWeightRisk Ratio IV, Fixed, 95% CIRisk Ratio IV, Fixed, 95% CI
Study or Subgroup
Borges 2013-0.42351.35171.6%0.65 [0.05. 9.26]
Ciftici 20011.04980.39118.7%2.86 [1.33. 6.15]
Custodio 20130.081.00322.8%1.08 [0.15. 7.74]
Dalligna 20140.33210.5768.6%1.39 [0.45, 4.31]
Damiani 19950.29110.436415.0%1.34 [0.57. 3.15]
Gonc 20140.470.79844.5%1.60 [0.33. 7.65]
Lonarevic 20080.22310.80624.4%1.25 [0.26, 6.07]
Lorea 2012-0.42351.35171.6%0.65 [0.05. 9.26]
Mayer 19970.10541.49441.3%1.11 [0.06. 20.79]
McDonnell 20031.43510.99522.9%4.20 [0.60, 29.54]
Monteiro 20190.28771.51.3%1.33 [0.07. 25.22]
Narasismhan 2003-0.22311.33231.6%0.80 [0.06. 10.89]
Parise 2019-0.26240.65346.7%0.77 [0.21. 2.77]
Pinto 20170.55430.506511.2%1.74 [0.65. 4.70]
Pinto 20201.19390.68986.0%3.30 [0.85. 12.75]
Rosati 2008-0.77321.25321.8%0.46 [0.04. 5.38]
Sandrini 20041.15270.88363.7%3.17 [0.56, 17.90]
Wilkin 20000.51081.43761.4%1.67 [0.10. 27.89]
Zekri 20190.0690.75915.0%1.07 [0.24. 4.74]
Total (95% CI)100.0%1.63 [1.17, 2.27]
Heterogeneity: Chiª = 9.07, df = 18 (P = 0.96); P= Test for overall effect: Z = 2.88 (P = 0.004)0%0.050.2 1 5 20
Favours[non secreting] Favours [secreting]

200

FIGURE 3 Forest plots showing risk ratio (RR) (A) according to Cushing’s syndrome (Cushing vs non-Cushing); and (B) secretion status (secreting vs nonsecreting tumors), for each study and pooled for all studies. Only first author of each study is given

aSERisk RatioRiskRatio 95% CI
Study or Subgrouplog[Risk Ratio]WeightIV, Fixed, 95% CIIV, Fixed,
Bergada 19961.38631.2994.2%4.00 [0.31, 51.02]
Borges 20132.86371.01566.9%17.53 [2.39, 128.28]
Custodio 20131.87181.08316.1%6.50 [0.78, 54.31]
Damiani 19951.68950.674315.6%5.42 [1.44, 20.31]
Lorea 20122.94441.01456.9%19.00 [2.60, 138.77]
McDonnell 20032.12821.38533.7%8.40 [0.56, 126.89]
Mendonca 19951.60941.26494,4%5.00 [0.42, 59.65]
Mishra 20010.69310.707114.2%2.00 [0.50. 8.00]
Narasismhan 2003-0.76211.3873.7%0.47 [0.03. 7.07]
Parise 20192.07940.99547.2%8.00 [1.14, 56.28]
Pinto 20051.79181.55462.9%6.00 [0.29. 126.31]
Pinto 20173.38391.40583.6%29.49 [1.87, 463.69]
Sakoda 20141.54040.70514.3%4.67 [1.17, 18.58]
Wilkin 20000.91631.51663.1%2.50 [0.13, 48.85]
Wolthers 19992.14841.47443.3%8.57 [0.48, 154.19]
Total (95% CI)100.0%5.46 [3.24, 9.20]
Heterogeneity: Chiª = 10.17, df= 14 (P = 0.75); P= 0% Test for overall effect: Z = 6.37 (P < 0.00001)0.0020.1 1 10
Favours [>100g]Favours [<100g]

200

500

FIGURE 4 Forest plots showing risk ratio (RR) according to tumor weight for each study and pooled for all studies in (A) <100 g versus >100 g, and (B) <400 g versus >400 g. Only first author of each study is given
blog[Risk Ratio]SEWeightRisk Ratio IV, Fixed, 95% CIRisk Ratio IV. Fixed, 95% CI
Study or Subgroup
Bergada 19961.73461.2681.4%5.67 [0.47, 68.02]
Borges 20131.54040.50349.0%4.67 [1.74, 12.52]
Chatterjee 20152.10011.40581.2%8.17 [0.52, 128.43]
Custodio 20131.32180.96612.5%3.75 [0.56, 24.91]
Damiani 19951.29580.345119.2%3.65 [1.86, 7.19]
Jehangir 20192.60271.01382.2%13.50 [1.85, 98.47]
Lorea 20121.59990.50469.0%4.95 [1.84, 13.32]
McDonnell 20031.49170.783.8%4.44 [0.96. 20.50]
Mishra 20010.98080.58456.7%2.67 [0.85, 8.38]
Narasismhan 2003-0.22311.33231.3%0.80 [0.06. 10.89]
Parise 20191.40180.364317.2%4.06 [1.99, 8.30]
Pinto 20052.70811.50551.0%15.00 [0.78, 286.81]
Pinto 20172.00720.51088.8%7.44 [2.73, 20.25]
Sakoda 20141.25280.388715.1%3.50 [1.63, 7.50]
Wolthers 19992.01491.19721.6%7.50 [0.72, 78.36]
Total (95% CI)100.0%4.29 [3.19, 5.78]
Heterogeneity: Chi? = 6.50, df= 14 (P = 0.95); P= 0% Test for overall effect: Z = 9.63 (P < 0.00001)0.0050.1 1 10
Favours [>400 g] Favours [<400 g]
alog[Risk Ratio)SEWeightRisk Ratio IV, Fixed, 95% CIRisk Ratio IV, Fixed, 95% CI
Study or Subgroup
Chatterjee 20150.74191.3615.8%2.10 [0.15, 30.25]
Dalligna 20142.38851.41265.4%10.90 [0.68, 173.67]
Das 20161.15751.41245.4%3.18 [0.20, 50.69]
Federici 19941.32181.4525.1%3.75 [0.22, 64.56]
Fragoso 20122.39791.42415.3%11.00 [0.67, 179.30]
Kerkhofs 20141.04981.41675.4%2.86 [0.18, 45.90]
Latronico 20011.32181.56264.4%3.75 [0.18, 80.19]
Mayer 19970.62861.53034.6%1.87 [0.09, 37.63]
McDonnell 20031.94591.41425.4%7.00 [0.44, 111.91]
Mendonca 19951.92791.47795.0%6.88 [0.38, 124.53]
Mishra 20010.22310.741619.7%1.25 [0.29, 5.35]
Narasismhan 20030.22311.2457.0%1.25 [0.11, 14.34]
Sakoda 20141.16320.974711.4%3.20 [0.47, 21.62]
Wilkin 20000.40551.51384.7%1.50 [0.08. 29.15]
Wolthers 19991.97411.43955.2%7.20 [0.43, 120.96]
Total (95% CI)100.0%2.98 [1.56, 5.67]
Heterogeneity: ChP = 5.02, df= 14 (P = 0.99); P= 0%0.0050.1 1 10
Test for overall effect: Z= 3.32 (P = 0.0009)Favours [>5 cm]Favours [<5 cm]

200

200

FIGURE 5 Forest plots showing risk ratio (RR) according to tumor size diameter for each study and pooled for all studies: (A) maximum size <5 cm versus >5 cm, and in (B) maximum size <10 cm versus >10 cm. Only first author of each study is given
Risk Ratio Risk Ratio IV, Fixed, 95% CI IV, Fixed, 95% CI
blog[Risk Ratio)SEWeight
Study or Subgroup
>10 cm
Chatterjee 20152.41591.40032.5%11.20 [0.72, 174.24]
Dall'igna 20141.38630.496419.6%4.00 [1.51, 10.58]
Das 20162.45671.42092.4%11.67 [0.72, 188.97]
Federici 19942.90871.40562.4%18.33 [1.17, 288.19]
Fragoso 20121.70040.555815.7%5.48 [1.84, 16.28]
Jehangir 20191.22381.31952.8%3.40 [0.26, 45.15]
Kerkhofs 20141.79181.42592.4%6.00 [0.37, 98.15]
Mayer 19970.10541.49442.2%1.11 [0.06, 20.79]
McDonnell 20031.81010.80157.5%6.11 [1.27, 29.40]
Mendonca 19952.01491.19723.4%7.50 [0.72, 78.36]
Mishra 20010.15420.83097.0%1.17 [0.23. 5.95]
Narasismhan 2003-0.10541.33752.7%0.90 [0.07, 12.38]
Sakoda 20141.07610.487720.3%2.93 [1.13. 7.63]
Wilkin 200001.49072.2%1.00 [0.05, 18.57]
Wolthers 19991.65820.83816.9%5.25 [1.02, 27.14]
Total (95% CI)100.0%3.87 [2.51, 5.96]
Heterogeneity: ChP = 8.78, df = 14 (P = 0.84); P=0%0.0050.1 1 10
Test for overall effect: Z = 6.15 (P <0.00001)Favours [<10cm]Favours [>10cm]

in a worse outcome for those >5 cm (P = . 0009; RR 2.98; 95% CI 1.56-5.67; I 2 0%) (Figure 5A). Finally, the last meta-analysis among 15 studies5,19,22,23,25,28,29,32-35,37,42,45,52 showed that tumors larger than 10 cm had worse outcome (P < .00001; RR 3.87; 95% CI 2.51-5.96; I 2 0%) (Figure 5B).

3.7 Surgery results

A meta-analysis (Supporting Information S3) including 13 studies5,20,23,36,27,32,33,37,38,42,51,53,54 compared the outcome between patients undergone complete resection and those undergone incom- plete resection. The first ones showed a better outcome (P < . 00001; RR 3.50; 95% CI 2.51-4.88; /2 16%).

3.8 Stage

Five different meta-analyses assessed the impact on the outcome of the different stage of disease at diagnosis (Supporting Information S4). The stages were compared as follows. Stage I versus Stage II, III, and IV included eight studies.7,18,20,31,36,38,40,46 The meta-analysis showed a better outcome for Stage I (P < . 00001; RR 6.94; 95% CI 3.35- 14.4; I 2 12%). Then, Stage I versus Stage II and III included seven studies.7,18,20,31,38,40,46 This resulted in a better outcome for patients with Stage I disease (P < .00001; RR 4.69; 95% CI 2.11-10.4; I 2 28%). Stage I versus Stage II, including six studies,7,18,20,31,38,40 showed a bet- ter outcome once again for Stage I (P <. 002; RR 5.02; 95% CI 1.82-13.9;

I 2 53%). Stage II was compared to Stage III in six studies,18,20,31,38,40,46 and no difference was found (P < .12; RR 1.93; 95% CI 0.84-4.47; I 2 39%). Lower stages (Stage I and II) versus advanced disease (Stage III and IV) showed RR of 4.99 for advanced tumors (95% CI 3.57-6.98; P <. 00001; /2 0%).7,18,20,31,36,38,40,46

4 DISCUSSION

4.1 Main findings

The findings from this systematic review partially confirmed the previ- ous reports. Age <4 years, R0 resection, tumor diameter <5 cm, tumor volume <200 cm3, tumor weight <100 g and <400 g, and lower stage at diagnosis strongly correlated with good outcome. An association with worse outcome was also found when patients presenting with Cushing syndrome were compared with patients without Cushingoid features (secreting and nonsecreting together), but not when com- pared with nonsecreting tumors only. Secreting tumors showed a slight increase in the RR when compared with nonsecreting tumors. Lower stages are associated with a better outcome independently from the inclusion of metastatic patients into the analysis.

4.2 Limitations

Limitations and bias derived from the features of the studies are included in this review. The main weaknesses of these series were

represented by their retrospective design, small sample size, dif- ferent thresholds or classifications used (such as to describe vol- ume and weight, or stage), and by the fact that most of the stud- ies did not explore all the clinical features taken into account by this systematic review. The variability in the thresholds limited the evaluation of some clinical features, as it lowered the number of patients who entered the single analysis, decreasing the rate of events. In this scenario, it is plausible that the relationship between a given clinical feature and the outcome may have been under- or overestimated.

4.3 Implications for clinical practice

The current pathological scores may not be sufficient to determine the malignant behavior of localized ACTs, especially in case of a Stage II-III disease. The Wieneke index seems to be the most reliable score in pedi- atric age so far,5,6,27 but because it addresses a group of tumors with indeterminate malignancy, it still leaves partially unsolved the deci- sion on which may be the best postoperative treatment (chemotherapy associated to mitotane or mitotane alone) for this subset of patients.

In the past, various clinical features have been considered to be associated with poor outcome, but they varied depending on the study: age >4 years, size, Cushing syndrome, incomplete resections, and stage have been more commonly reported. Additionally, initial biopsy is con- sidered to be an unfavorable prognostic factor and it should be avoided as much as possible.2,8,47,55,56 Moreover, few attempts have been made to overcome this variability of evidence before the present study, but they retrospectively took into account a limited number of patients and without reaching a wider consensus on a possible risk stratification. A paper published by the European group (EXPERT) tried to define a subset of “high-risk” tumors based on the presence of one of the fol- lowing features: age at diagnosis, volume more than 200 cm3, Cushing syndrome, initial biopsy (open or tru-cut), surgical excision with resid- uals or spillage, regional lymph node involvement, histologic vascular invasion, and distant metastases at diagnosis.8 An analysis performed on 111 patients of the American National Cancer Data Base suggested including in the risk stratification age, extension into adjacent organs, metastases, and incomplete resection.55

Identifying some clinical features, in order to stratify patients who are at major risk of relapse, could lead to identifying a subgroup of ACT which may be elected to a systemic treatment after surgery, but also in which a mini-invasive approach at diagnosis should be avoided.

The use of adjuvant mitotane for 24-36 months in some Stage II and III patients, alone or in combination with standard chemotherapy, has been found to be determinant56-59 to improve overall survival and event-free survival. In these cases, a distinction between benign and malignant forms may in turn avoid important and unnecessary side effects, or represent a possible improvement in terms of survival.

Indeed, the use of a mini-invasive approach (laparoscopic or robotic- assisted) in ACT is also the object of debate: some authors suggested that it could be associated with a higher rate of incomplete resection

or spillage60 and discouraged this technique.61,62 The definition of pre- operative clinical risk factors (eg, age >4 years, Cushing syndrome, or nonsecreting tumor), aside from size and suspicious nodes or exten- sion into adjacent organ at imaging, could drive the surgeon’s decision in order to avoid unnecessary hazards with potentially fatal outcomes.

4.4 Implications for research

Despite the presence of national registries and large studies, and a considerable number of ACT patients reported in the literature, the prognostic value to be attributed to a given clinical feature is currently extremely variable. For this reason, international cooperative studies or registries prospectively aimed at defining a risk stratification for pediatric ACT, ideally based both on clinical and histological features, are needed. These studies should consider prospectively the predictive accuracy of the different features, alone and in combination. The opti- mal cutoffs of quantitative variables, such as size and volume, should be investigated in order to provide a precise estimation of the pre- and postsurgical risk of localized ACT. Furthermore, such studies should provide standardization for qualitative variables in order to homoge- nize data collected in different countries (eg, staging or tumor scores).

5 CONCLUSIONS

As expected, localized small tumors did show a better prognosis: a low stage, size <10 cm, and weight under 100 g seem to have lesser risk of death. Some clinical factors (age >4 years, Cushing syndrome) corre- lated with a worse outcome and, despite the biological reasons being far from clear, they could be considered when stratifying patients or before planning the surgical approach at diagnosis. Notwithstanding its limitations, this systematic review strengthened in part the evidence coming from the previous literature, and it could be considered a step forward for risk stratification for pediatric ACT.

ACKNOWLEDGMENTS

We thank Carlos Alberto Scrideli (Pediatrics Department, Ribeira õ Preto Medical School, University of Sao Paulo, Brazil) for his contribu- tions to this systematic review in terms of additional explanations on their published data and unpublished data supplied.

CONFLICT OF INTEREST

The authors declare that there is no conflict of interest.

DATA AVAILABILITY STATEMENT

The data that support the findings of this study are available on request from the corresponding author.

ORCID

Elisa Zambaiti (D https://orcid.org/0000-0002-9610-1708 Patrizia Dall’Igna D https://orcid.org/0000-0002-3822-3272 Calogero Virgone (D https://orcid.org/0000-0002-3651-9416

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SUPPORTING INFORMATION

Additional supporting information may be found online in the Support- ing Information section at the end of the article.

How to cite this article: Zambaiti E, Duci M, De Corti F, et al. Clinical prognostic factors in pediatric adrenocortical tumors: A meta-analysis. Pediatr Blood Cancer. 2020;e28836. https://doi.org/10.1002/pbc.28836