Biphasic reduction and concanavalin A binding properties of serum alpha-fetoprotein in preterm and term infants

The Diagnostic Accuracy of Serum Alpha-Fetoprotein Levels in Follow-up for Recurrence of Sacrococcygeal Teratoma; a Nationwide Review of SCT Cases in the Netherlands

BACKGROUND

Serum alpha-fetoprotein (AFP) is often used as tumour marker for recurrent sacrococcygeal teratoma (SCT). We aimed to assess the normal dynamics of serum AFP levels after initial resection and diagnostic accuracy of serum AFP levels the follow-up for recurrence in SCT.

METHODS

This retrospective study included 57 patients treated for SCT in the six pediatric surgical centers in the Netherlands from 1980 to 2018.

MAIN RESULTS

57 patients were included in the study of whom 19 children developed 20 recurrences at a median of 14.0 months after initial resection. No significant difference was found in serum AFP level dynamics between the recurrence and non-recurrence group after initial resection (p = 0.950). Serum AFP levels did not significantly increase before recurrence (p = 0.106) compared to serum AFP levels of children without recurrence at the same time. However, serum AFP levels did significantly increase in malignant recurrences (n = 7) (p = 0.03) compared to patients without recurrence. A cut-off value of 55 μg/L was found to be predictive for recurrent SCT with an Area Under the Curve (AUC) of 0.636 with sensitivity of 50% and specificity of 100%.

CONCLUSION

Dynamics of serum AFP levels are not different between patients with and without recurrence after initial resection of SCT. Serum AFP levels are not predictive for mature or immature recurrent SCT and normal AFP levels do not rule out recurrent SCT. However, serum AFP levels exceeding 55 μg/L can indicate recurrent SCT, especially malignant recurrences.

Type 1 tyrosinemia in Finland: a nationwide study

Background

Introduction of nitisinone and newborn screening (NBS) have transformed the treatment of type 1 tyrosinemia, but the effects of these changes on the long-term outcomes remain obscure. Also, the predictors for later complications, the significance of drug levels and the normalization of laboratory and imaging findings are poorly known. We investigated these issues in a nationwide study.

Results

Type 1 tyrosinemia was diagnosed in 22 children in 1978–2019 in Finland. Incidence was 1/90,102, with a significant enrichment in South Ostrobothnia (1/9990). Median age at diagnosis was 5 (range 0.5–36) months, 55% were girls and 13 had homozygotic Trp262X mutation. Four patients were detected through screening and 18 clinically, their main findings being liver failure (50% vs. 100%, respectively, p = 0.026), ascites (0% vs. 53%, p = 0.104), renal tubulopathy (0% vs. 65%, p = 0.035), rickets (25% vs. 65%, p = 0.272), growth failure (0% vs. 66%, p = 0.029), thrombocytopenia (25% vs. 88%, p = 0.028) and anaemia (0% vs. 47%, p = 0.131). One patient was treated with diet, seven with transplantation and 14 with nitisinone. Three late-diagnosed (6–33 months) nitisinone treated patients needed transplantation later. Kidney dysfunction (86% vs. 7%, p = 0.001), hypertension (57% vs. 7%, p = 0.025) and osteopenia/osteoporosis (71% vs. 14%, p = 0.017) were more frequent in transplanted than nitisinone-treated patients. Blood/serum alpha-fetoprotein decreased rapidly on nitisinone in all but one patient, who later developed intrahepatic hepatocellular carcinoma. Liver values normalized in 31 months and other laboratory values except thrombocytopenia within 18 months. Imaging findings normalized in 3–56 months excluding five patients with liver or splenic abnormalities. Low mean nitisinone concentration was associated with higher risk of severe complications (r = 0.758, p = 0.003) despite undetectable urine succinylacetone.

Conclusions

Prognosis of type 1 tyrosinemia has improved in the era of nitisinone, and NBS seems to provide further benefits. Nevertheless, the long-term risk for complications remains, particularly in the case of late diagnosis and/or insufficient nitisinone levels.

Diagnostic accuracy of serum alpha-fetoprotein levels in diagnosing recurrent sacrococcygeal teratoma: A systematic review

BACKGROUND

The incidence of children developing recurrent sacrococcygeal teratoma (SCT) is 2-35%. Serum alpha-fetoprotein (AFP) is often used as a tumor marker for (malignant) recurrences of SCT and could potentially be used during routine follow-up after SCT resection. However, the diagnostic accuracy of serum AFP levels during follow-up has not been well established. Therefore, we aimed to systematically review the diagnostic accuracy of serum AFP levels in recurrent SCT.

METHODS

We queried Search Premier, COCHRANE Library, EMCARE, EMBASE, PubMed, ScienceDirect and Web of Science databases to identify studies regarding patients with SCT with follow-up using serum AFP levels postoperative. We estimated sensitivity and specificity of serum AFP levels.

RESULTS

Fifteen studies (613 patients, 121 recurrences) were included and these mainly described serum AFP levels in patients with recurrent SCT (n = 111); 83 (75%) patients with recurrent SCT had elevated serum AFP levels. A subgroup analysis of articles that measured serum AFP levels in all patients (n = 6, 136 patients, 14 recurrences) showed a sensitivity and specificity of 79% and 95%, respectively. The sensitivity of AFP levels to detect malignant recurrence was 96%.

CONCLUSION

Diagnostic accuracy of serum AFP levels to detect recurrent SCT seems promising, though sensitivity could be overestimated since serum AFP levels are mainly described in patients with elevated AFP levels or at recurrent SCT. Furthermore, serum AFP levels could be helpful to detect malignant recurrences.

TYPE OF STUDY

Systematic review of level 2-4 studies.

LEVEL OF EVIDENCE

Level 2-4 (mostly level 2).

Human Epididymis Protein 4 Levels in Neonates with Respiratory Disorder

Results

There were no differences found in the HE4 levels determined for the mothers' blood samples and umbilical cord blood samples in all investigated groups. In comparison with healthy children, the elevated HE4 levels were observed in neonates with TTN. Significant positive correlation between HE4 and CRP as well as PCT levels was observed in all investigated neonates. The receiver operating characteristic (ROC) curve analysis demonstrated the cut-off value for the serum HE4 in the researched neonates at the level of 318.5 pmol/L, yielding the sensitivity of 73.9% and specificity of 66.7% for the early diagnosis of TTN.

Conclusions

Serum HE4 could be considered as a candidate biomarker for the early diagnosis of pulmonary dysfunction in the newborns.

Development of the Serum α-Fetoprotein Reference Range in Patients with Beckwith-Wiedemann Spectrum

OBJECTIVE

To establish reference ranges for serum α-fetoprotein (AFP) at various ages in patients with Beckwith-Wiedemann spectrum (BWSp), to better predict the risk for hepatoblastoma in this population.

STUDY DESIGN

A retrospective analysis of AFP measurements collected from patients with BWSp was performed. Factors including sex, prematurity, molecular diagnosis of patients, and performing laboratory were evaluated for significant differences. In total, 1372 AFP values were collected from 147 patients and the predictive AFP values at various ages were calculated to establish reference ranges. Mixed-effects polynomial regression models were used to study various potential factors affecting log(AFP) values.

RESULTS

Overall, predicted AFP values declined to normal range for age (<10 ng/mL) by 14 months old. Patient sex and performing laboratory were found not to influence values. A significant difference was demonstrated between premature and nonpremature patients, and separate reference values were established. Significant differences in the predicted AFP value were not broadly apparent between molecular subtypes; however, interpretation was limited due to the small sample size of some of these subtypes.

CONCLUSIONS

Predictive AFP values were created for premature and nonpremature patients with BWSp to aid with interpretation and monitoring of the risk for hepatoblastoma. Further analysis is needed to determine whether AFP values differ within the less common molecular subtypes of patients with BWSsp.

Half-life of alpha-fetoprotein in neonatal sacrococcygeal teratoma

BACKGROUND

Alpha-fetoprotein (AFP) is useful as a tumor marker for sacrococcygeal teratoma (SCT). We investigated the half-life of AFP in SCT.

METHODS

Neonates who underwent surgical treatment for SCT between 1997 and 2016 were included in the study, whereas patients who died before or after surgery or had malignant germ cell tumors were excluded.

RESULTS

Fifty-five non-recurrent SCT patients (M:F = 18:37) were enrolled. They underwent surgery on average 7.4 ± 4.1 days after birth. Serum AFP was measured an average 4.25 ± 2.07 times per patient. We obtained 165 half-lives following the formula (M = Mo * (1/2) ^Δt/T). A positive correlation was observed between half-life and patient age using the formula T_1/2 = 0.0597 × days +6.1643 (p < 0.001). It was different from recurrent SCT (T_1/2 = 0.1196 × days -0.0633) (p < 0.05). Half-life was different between mature SCT (T_1/2 = 0.0671 × days +4.3912) and immature SCT (T_1/2 = 0.0433 × days +8.9339) (p < 0.05).

CONCLUSION

The half-life of AFP in neonatal patients with SCT was prolonged in proportion to the age, and it was getting longer in recurrent tumor than non-recurrent tumor. The half-life of AFP was longer in immature teratoma than in mature teratoma.

LEVEL OF EVIDENCE

IV.

Serum α-fetoprotein in pediatric oncology: not a children’s tale

Background

Measurement of α-fetoprotein (AFP) concentrations in the serum of infants is useful for the management of testicular germ cell tumors, hepatoblastoma and hepatocellular carcinoma. Here, we provide a critical review of the available information about pediatric reference intervals (RI), focusing on their utility in interpreting AFP as an aid for cancer diagnosis.

Content

Evidence sources in the available literature were critically appraised. Out of 3873 retrieved papers, 24 were finally selected and carefully inspected, and six of them overcame exclusion criteria (i.e. methodological limitations in the study design, statistical gaps, drawbacks in traceability of the AFP assay to higher order materials and/or biased reporting of AFP results). Preterm and term infants up to the 3rd month of life exhibited the highest average AFP concentrations, but the attempt of defining RI by data pooling and partitioning for age intervals was impeded by the wide variability of data. The inability of defining robust RI in the first months of life made difficult, if not impossible, using upper reference limits for ruling out malignancies with a single AFP result. Evaluating the behavior of AFP concentrations 5 days from the baseline result, if this exceeds risk thresholds partitioned for age, according to the formula Xt=X0*2−t/HL (where: t=days elapsed for AFP retest; HL=AFP half-life according to age; X0=AFP baseline concentration, and Xt=predicted AFP concentration at day 5), could give a better information.

Summary

Novel studies defining AFP RI in infants based on robust methodology are warranted to improve the interpretation of AFP results in pediatric oncology. In the meantime, algorithms based on both serum AFP absolute concentrations and HL may aid in cancer diagnosis.

Serum α-fetoprotein concentration in extremely low-birthweight infants

BACKGROUND

Extremely low-birthweight infants (ELBWI) are at greater risk of developing hepatoblastoma than are normal-weight infants. Serum α-fetoprotein (AFP) plays an important role as a tumor marker in the diagnosis of hepatoblastoma, therefore the aim of this study was to determine the changes in serum AFP concentration after birth in ELBWI.

METHODS

Data were obtained for infants born between January 2005 and March 2008 with birthweight <1000 g who were followed up at Gunma Children's Medical Center with clinical examinations, including monitoring of the development of hepatoblastoma. The relationship between serum AFP concentration and age was analyzed up to 730 days after birth.

RESULTS

Overall, 95 serum AFP measurements were obtained from 23 infants 30-730 days of age, with gestational age 24-32 weeks, and birthweight 498-982 g. Log₁₀ (AFP [ng/mL]) was significantly correlated with log₁₀ (age [days]) (r = -0.961, P = 0.000, n = 95), with the following regression formula: log₁₀ (AFP [ng/mL]) = 11.063 - 3.752 log₁₀ (age [days]) (adjusted R²  = 0.923, n = 95). The standard error of the estimate, mean log₁₀ (age [days]), and the sum of squares for log₁₀ (age [days]) were 0.363, 2.503, and 10.579, respectively.

CONCLUSIONS

A correlation was found between serum AFP concentration and age in ELBWI, and the 95%CI of serum AFP concentration was determined for ELBWI up to 2 years after birth.

Overview of pediatric testicular tumors in Korea

Prepubertal testicular tumors are rare compared with postpubertal testicular tumors. The incidence of prepubertal testicular tumors peaks at 2 years of age, tapers off after 4 years of age, and then begins to rise again at puberty. Prepubertal and postpubertal testicular tumors show many differences, including the typical tumor histology, molecular biological differences, and the malignant potential of tumors at different ages. Pediatric testicular tumors are classified as benign or malignant on the basis of their clinical behavior and histologically are divided into germ cell and gonadal stromal (nongerm cell) tumors. Many histological and biological studies have further confirmed the distinct nature of prepubertal and postpubertal testicular tumors. These differences have led to various management strategies for prepubertal and postpubertal tumors. Because overall about 75% of prepubertal testicular tumors are benign, a testis-sparing approach is becoming more common in children. Orchiectomy and observation with very selective use of chemotherapy has become the standard approach when a malignant tumor is identified. Retroperitoneal lymph node dissection and radiation therapy play very limited roles.

Pediatric Population Reference Value Distributions for Cancer Biomarkers and Covariate-Stratified Reference Intervals in the CALIPER Cohort

BACKGROUND

Cancer biomarkers are commonly used in pediatrics to monitor cancer progression, recurrence, and prognosis, but pediatric reference value distributions have not been well established for these markers. The Canadian Laboratory Initiative on Pediatric Reference Intervals (CALIPER) sought to develop a pediatric database of covariate-stratified reference value distributions for 11 key circulating tumor markers, including those used in assessment of patients with childhood or adult cancers.

METHODS

Healthy community children from birth to 18 years of age were recruited to participate in the CALIPER project with informed parental consent. We analyzed serum samples from 400–700 children (depending on the analyte in question) on the Abbott Architect ci4100 and established reference intervals for α-fetoprotein (AFP), antithyroglobulin (anti-Tg), human epididymis protein 4 (HE4), cancer antigen 125 (CA125), CA15-3, CA19-9, progastrin-releasing peptide (proGRP), carcinoembryonic antigen (CEA), squamous cell carcinoma antigen (SCC), and total and free prostate specific antigen (PSA) according to CLSI C28-A3 statistical guidelines.

RESULTS

We observed significant fluctuations in biomarker concentrations by age and/or sex in 10 of 11 biomarkers investigated. Age partitioning was required for CA153, CA125, CA19-9, CEA, SCC, proGRP, total and free PSA, HE4, and AFP, whereas sex partitioning was also required for CA125, CA19-9, and total and free PSA.

CONCLUSIONS

This CALIPER study established a database of childhood reference intervals for 11 tumor biomarkers and revealed dramatic fluctuations in tumor marker concentrations between boys and girls and throughout childhood. In addition, important differences between the adult and pediatric population were observed, further highlighting the need for pediatric-specific reference intervals.

Prepubertal testicular tumors: frequently overlooked

OBJECTIVE

Prepubertal testicular tumors are fundamentally distinct from their adult counterparts. We reviewed our 10-year, two-institution experience with respect to diagnosis and treatment.

MATERIAL AND METHODS

A retrospective review was performed of all testicular tumors diagnosed between 1996 and 2006 in males younger than 14 years. We analyzed clinical characteristics, diagnostic procedures, treatment methods, histopathologic findings and outcome.

RESULTS

Of 15 primary testicular tumors, eight (53%) were germ-cell tumors (three teratomas, two yolk sac tumors, one seminoma, one embryonic carcinoma and one choriocarcinoma), four (27%) tumor-like lesions (epidermoid cysts), two (13%) gonadal stromal tumors (a Leydig and a Sertoli cell tumor), and one (7%) gonadoblastoma with gonadal dysgenesis. All boys were presented with a painless scrotal mass and four (27%) of them with elevated tumor markers. Ten cases (66%) were misdiagnosed by urologists preoperatively and presented for treatment of congenital or acquired scrotal disorders. Twelve children (80%) were treated with radical orchiectomy and three (20%) with a testis-sparing procedure. At a mean 4-year follow-up no patient has presented with recurrent tumor in the residual or contralateral testicle. Postoperative physical examination and scrotal ultrasound were obtained in 14 patients at a median follow-up of 48.2 months, and there was no evidence of tumor progression. One boy with a choriocarcinoma (stage IV) died due to distant metastases.

CONCLUSIONS

Benign teratoma and epidermoid cysts were the most common prepubertal testicular tumors. Any suspicion of a testicular tumor warrants an inguinal approach to prevent scrotal violation of the tumor. Our limited experience with testis-sparing procedures supports the current trends that organ-confined surgery should be performed for benign lesions such as teratoma, Leydig cell tumor and epidermoid cysts based on frozen biopsy findings.

Current strategies for the treatment of hereditary tyrosinemia type I

Hereditary tyrosinemia type I (HT-I) is the most common of the three known diseases caused by defects in tyrosine metabolism. This type of tyrosinemia is caused by a mutation in the gene coding for fumarylacetoacetate hydrolase; several mutations in this gene have been identified. The main clinical features of HT-I are caused by hepatic involvement and renal tubular dysfunction. Dietary intervention with restriction of phenylalanine and tyrosine together with supportive measures can ameliorate the symptoms, but given the high risk for hepatocellular carcinoma, a cure for these patients has so far been possible only with liver transplantation. Pharmacologic treatment with nitisinone, a peroral inhibitor of the tyrosine catabolic pathway, offers an improved means of treatment for patients with HT-I. However, longer follow-up periods are needed to establish the role of this drug in ultimately protecting patients from end-stage organ involvement and hepatocellular carcinoma. Experimental work in mice has provided some promise for the future management of tyrosinemia with gene therapy.

Pediatric testicular tumors: contemporary incidence and efficacy of testicular preserving surgery

PURPOSE

Testicular tumors in the pediatric population are fundamentally distinct from their adult counterparts. We reviewed a contemporary single series from a large pediatric health science center. We also examined our experience with testis conserving surgery and then used it to develop a preoperative management algorithm.

MATERIALS AND METHODS

A retrospective review was performed of all testicular tumors at a single institution from 1984 to 2002. Data were compiled using the American Academy of Pediatrics testis tumor registry data collection form. We further examined partial orchiectomies for indications and outcomes with respect to cancer control and testicular viability.

RESULTS

A total of 51 primary testicular lesions were identified. Patient age was prenatal to 16 years with a scrotal mass the most common presentation (81%). Mature teratoma, rhabdomyosarcoma, epidermoid cyst, yolk sac and germ cell tumors accounted for 43%, 26%, 10%, 8% and 6% of cases, respectively. This distribution was markedly different from the last reported American Academy of Pediatrics data base. Organ preserving surgery was planned and achieved in 13 cases. All surgeries were successful with respect to cancer control and testicular preservation.

CONCLUSIONS

We believe that the higher incidence of teratoma is more representative of this population and yolk sac tumor is a minority diagnosis. The single institution review eliminates the interinstitutional referral heterogeneity that may have skewed larger data bases. Furthermore, the concept of testicular preserving surgery becomes an attractive option since we present its safety and efficacy. The management algorithm should facilitate the preoperative decision to perform less radical surgery and help preserve testicular tissue.

Serum alpha-fetoprotein screening for hepatoblastoma in children with Beckwith-Wiedemann syndrome or isolated hemihyperplasia

An elevated risk of hepatoblastoma for children with Beckwith-Wiedemann syndrome or isolated hemihyperplasia is well established. We describe five children with Beckwith-Wiedemann syndrome or isolated hemihyperplasia for whom serial serum alpha-fetoprotein screening, usually in combination with abdominal ultrasound, led to early detection of hepatoblastoma.

Clinical use of tumor markers in childhood malignancies

Tumor markers are developmentally regulated proteins or carbohydrate molecules, which are expressed in specific tissues in the fetus during certain developmental periods. With malignant transformation, these molecules are reexpressed in neoplastic tissues. Some developmental or metabolic disorders can also lead to the expression of tumor marker genes, hereditary tyrosinaemia and ataxia teleangiectasia associating with elevated serum alpha-fetoprotein are examples of such conditions. In pediatric malignancies, the most common markers in clinical use are alpha-fetoprotein in liver and yolk sac tumors, chorionic gonadotropin in germ cell tumors, and catecholamines and neuron specific enolase in neuroblastoma. Several other molecules including carbohydrate antigens CA 19-9 and CA 125 may also have a role in the diagnosis and follow-up of distinct types of childhood malignancies. The non-specificity of several markers, such as tissue polypeptide antigen and sialic acid, greatly hampers their clinical use. In this review we will discuss the biology and current knowledge on the use of serum and urine tumor markers. We also highlight the putative future use of these molecules in cancer diagnosis and therapy, including the use of monoclonal antibodies directed against these antigens.

Current management of prepubertal yolk sac tumors of the testis

Over the last 3 decades, the management of pediatric yolk sac tumors of the testis has changed significantly. These changes reflect improvement in the treatment of testicular tumors in adults and children, such as the advent of platinum-based chemotherapy regimens. They also reflect increased understanding of the biology and natural history of prepubertal yolk sac tumors of the testis as a unique disease entity.

Alpha 1-fetoprotein (AFP) reference values in infants up to 2 years of age

The aim of this study was to establish reference values and factors associated with serum AFP elevation in infants. Five hundred twenty-four samples collected from infants up to the age of 2 years at the University Hospital Düsseldorf (Germany) were analyzed. At birth mean serum AFP levels were 41,687 ng/ml in 256 term babies and 158,125 ng/ml in 90 premature babies born before the 37th gestational week, excluding samples from children with factors known to be associated with AFP elevation. In the first 4 weeks of life, AFP levels decreased by 50% in 5.1 days in term babies. Between day 180 and 720 of life, AFP levels up to 87 ng/ml were within the 95.5% interval (assumed logarithmic normal distribution) with a mean of 8 ng/ml without a further decline. By the age of 2 years the infants of this study had not reached adult serum AFP levels (0-6 ng/ml).

Maternal serum alpha-fetoprotein and epithelial tumour marker concentrations are not increased by fetal sacrococcygeal teratoma

Maternal serum alpha-fetoprotein (AFP) and total beta-human chorionic gonadotrophin (hCG) concentrations were measured at the 15th gestational week in ten pregnancies complicated by fetal sacrococcygeal teratoma. The findings corresponded to those in normal pregnancies. Similarly, third-trimester concentrations of cancer antigen 12-5, tumour-associated trypsin inhibitor, and the amino-terminal propeptide of type III procollagen in the maternal serum were not significantly elevated. Histologically mature and immature/malignant cases did not differ from each other as regards the above-mentioned parameters. This abnormality cannot be detected by maternal serum trisomy screening in the second trimester.