False-positive results in neuroblastoma screening: the parents' view

Continued use of scrotal ultrasounds for the workup of undescended testes: Confirmation bias and inaccuracies

AIM

Scrotal ultrasounds are utilised in some primary care settings for suspected cryptorchidism, despite inaccuracies. We aim to identify the correlation between ultrasound and primary care provider (PCP) findings of undescended testicles (UDTs) as a potential source of confirmation bias.

METHODS

Males referred for suspected UDT by PCPs who underwent scrotal ultrasound and paediatric urologist examination from 2014 to 2019 were included. Correlation between PCP and ultrasound findings and diagnostic accuracy were evaluated. Logistic regression was utilised to determine associations between patient factors and UDT misdiagnosis.

RESULTS

Out of 145 testes, ultrasound corroborated PCPs' UDT diagnoses 87.6% of the time, 49.6% of which were confirmed as UDT by paediatric urologists. Ultrasound had a false positivity rate of 81.0% and specificity of 19.0%. Ultrasound versus paediatric urologist findings regarding testicle location were significantly different (P < 0.0001). Patients aged ≥8 years old had 5.2 times greater odds of being misdiagnosed with UDT than patients <8 years old (95% confidence interval: 1.6-16.7; P < 0.002) by PCP and ultrasound.

CONCLUSION

Scrotal ultrasound highly corroborated PCPs' UDT diagnoses. Older patients were more likely to be misdiagnosed with UDT by PCP and ultrasound. As ultrasounds rarely refute PCP examinations for suspected UDTs and are highly inaccurate, confirmation bias may explain the use of ultrasound in the workup of UDT.

Effectiveness of screening for neuroblastoma at 6 months of age: a retrospective population-based cohort study

BACKGROUND

In Japan, a nationwide programme between 1984 and 2003 screened all infants for urinary catecholamine metabolites as a marker for neuroblastoma. Before 1989, this was done by qualitative spot tests for vanillylmandelic acid in urine, and subsequently by quantitative assay with high-performance liquid chromatography (HPLC). However, the Japanese government stopped the mass-screening programme in 2003, after reports that it did not reduce mortality due to neuroblastoma. We aimed to assess the effectiveness of the programme, by comparing the rates of incidence and mortality from neuroblastomas diagnosed before 6 years of age in three cohorts.

METHODS

We did a retrospective population-based cohort study on all children born between 1980 and 1998, except for a 2-year period from 1984. We divided these 22,289,695 children into three cohorts: children born before screening in 1980-83 (n=6,130,423); those born during qualitative screening in 1986-89 (n=5,290,412); and those born during quantitative screening 1990-98 (n=10,868,860). We used databases from hospitals, screening centres, and national cancer registries. Cases of neuroblastoma were followed up for a mean of 78.7 months.

FINDINGS

21.56 cases of neuroblastoma per 100,000 births over 72 months were identified in the qualitatively screened group (relative risk [RR] 1.87, 95% CI 1.66-2.10), and 29.80 cases per 100,000 births over 72 months in the quantitatively screened group (RR 2.58, 2.33-2.86). The cumulative incidence of neuroblastoma in the prescreening cohort (11.56 cases per 100,000 births over 72 months) was lower than that in other cohorts (p<0.0001 for all comparisons), but more neuroblastomas were diagnosed after 24 months of age in this cohort (p=0.0002 for qualitative screening vs prescreening, p<0.0001 for quantitative screening vs prescreening). Cumulative mortality was lower in the qualitative screening (3.90 cases per 100,000 livebirths over 72 months) and quantitative screening cohorts (2.83 cases) than in the prescreening cohort (5.38 cases). Compared with the prescreening cohort, the relative risk of mortality was 0.73 (95% CI 0.58-0.90) for qualitative screening, and 0.53 (0.42-0.63) for quantitative screening. Mortality rates for both the qualitative and quantitative screening groups were lower than were those for the prescreening cohort (p=0.0041 for prescreening vs qualitative screening, p<0.0001 for prescreening vs quantitative screening).

INTERPRETATION

More infantile neuroblastomas were recorded in children who were screened for neuroblastoma at 6 months of age than in those who were not. The mortality rate from neuroblastoma in children who were screened at 6 months was lower than that in the prescreening cohort, especially in children screened by quantitative HPLC. Any new screening programme should aim to decrease mortality, but also to minimise overdiagnosis of tumours with favourable prognoses (eg, by screening children at 18 months).

Newborn screening expands: recommendations for pediatricians and medical homes--implications for the system

Advances in newborn screening technology, coupled with recent advances in the diagnosis and treatment of rare but serious congenital conditions that affect newborn infants, provide increased opportunities for positively affecting the lives of children and their families. These advantages also pose new challenges to primary care pediatricians, both educationally and in response to the management of affected infants. Primary care pediatricians require immediate access to clinical and diagnostic information and guidance and have a proactive role to play in supporting the performance of the newborn screening system. Primary care pediatricians must develop office policies and procedures to ensure that newborn screening is conducted and that results are transmitted to them in a timely fashion; they must also develop strategies to use should these systems fail. In addition, collaboration with local, state, and national partners is essential for promoting actions and policies that will optimize the function of the newborn screening systems and ensure that families receive the full benefit of them.

"Wait and see" strategy in localized neuroblastoma in infants: an option not only for cases detected by mass screening

Neuroblastomas in infants may regress or mature spontaneously. Consequently, some authors have applied a "wait and see" strategy for tumors found by urinary mass screening. Recently, improved technique and increasing frequency of ultrasound examinations have led to an increase of neuroblastoma cases in pre- and post-natal period. We describe five cases, four diagnosed by routine ultrasound examination and one detected by urinary mass screening, who were monitored with a "wait and see" strategy in order to spare surgery. Median age at diagnosis was 4 months (range 2-10 months). All tumors were adrenal neuroblastomas. All patients met the following criteria: localized tumors, tumor size less than 5 cm in diameter, absence of invasive growth, vanillylmandelic acid (VMA) and homovanillic acid (HVA) less than 50 microg/mg creatinine, and informed consent of parents. Monitoring was performed by monthly ultrasound examinations and urine catecholamine analysis. Median follow-up is 14 months (5-28 months). Three tumors showed spontaneous regression, one is still under observation. In one patient the tumor increased in size and was resected after 14 months of observation displaying favorable histology, but chromosome 1p imbalance. Previous reports describe the adoption of a "wait and see" strategy in selected cases of localized neuroblastoma detected by mass screening. Our study confirms that this strategy may be similarly applied in incidentally or clinically detected cases. However, possible benefit has to be carefully balanced against possible risks.