Pediatric reference intervals for serum alpha-fetoprotein

Yolk sac tumor of the uterus in a 2-year-old girl: A case report and literature review

BACKGROUND

Extragonadal yolk sac tumors (YSTs) occurring in the uterus are extremely rare. To report a uterine YST case in a prepubertal girl and review literature on uterine YST to outline clinical management in diagnosis and treatment.

CASE

We present a case of a 2-year-old girl who presented with vaginal bleeding and a pelvic mass. The diagnosis of YST was confirmed via biopsy. After four cycles of neoadjuvant chemotherapy combined with cisplatin, etoposide, and bleomycin (PEB), vaginoscopic examination and laparoscopy revealed a uterine YST without metastasis. The patient was treated with laparoscopic hysterectomy and two cycles of PEB postoperatively. During the 18 months of follow-up, the patient remained disease-free.

SUMMARY AND CONCLUSION

Primary uterine YST is extremely rare and no treatment guidelines have been established to date. Surgery combined with PEB chemotherapy is considered effective for uterine YST.

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.

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.