Neuroblastoma screening in the United States: results of the Texas Outreach Program for Neuroblastoma Screening

Effectiveness of nationwide screening program for neuroblastoma in Japan

BACKGROUND

Neuroblastoma (NB) is one of the most malignant neoplasms in childhood. In Japan, while a nationwide screening program at six months of age was introduced in 1985, its efficacy has not been systematically evaluated before or after its introduction. The screening test was changed from a qualitative method to a quantitative method (i.e., high performance liquid chromatography, HPLC) with higher test precision around 1990. However, the Japanese government stopped the program in 2003, after reports which did not show a reduction in mortality from NB. To evaluate the effectiveness of the program, a systematic large-scale epidemiological study was conducted.

METHODS

A retrospective cohort study was carried out to evaluate the effectiveness of the NB screening with HPLC test at 6 months of age in Japan, in comparing mortality and incidence of NB after 6 months of age between screened children and concurrent non-screened children in the same area. The study cohort was defined retrospectively as those children who were born after the introduction of HPLC test, from its earliest introduction of January 1984 to December 31, 1997, in twenty-five prefectures of Japan, which cover approximately half of the newborn population of Japan.

RESULTS

The study cohort consisted of 4.31 million. We identified 66 NB deaths in the study cohort for the analysis after 6 months. Kaplan-Meier estimate of cumulative mortality of NB per million children at 6 years was 15.33 for the screened group and 32.63 for the non-screened group, respectively. The difference of hazard between the two groups was statistically significant. The age specific mortality rate ratio of NB (95% confidence interval (CI)) was statistically lower at 1 - 3 years [0.415 (0.212 - 0.810)]. The rate ratio of NB incidence (95% CI) at the early stage (i.e., 1, 2 and 4S) between them was statistically higher at 6 months - 1 year [9.56 (4.76 - 19.23)]. That of NB incidence at the advanced stage (i.e., 3 and 4) was statistically lower at 1 - 4 years [0.40 (0.26 - 0.62)].

CONCLUSION

The present study showed the reduction of mortality from NB, as well as the increase of the identification of early stage of NB and the decrease of advanced stage of NB. These findings strongly suggest the effectiveness of the NB screening with HPLC test in Japan. Although there could be several biases inherent to the study design, their possibilities are considered to be relatively low from observational information and theoretical consideration.

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).

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

PURPOSE

One of the major problems of any screening program is the occurrence of false-positive results. For neuroblastoma screening, little information is available on the psychological consequences for parents whose children had false-positive results that made further clinical evaluation necessary. It was the aim of this study to evaluate the parents' view by a semistructured interview.

PATIENTS AND METHODS

Among 267,302 infants screened in the Austrian study between 1991 and 1999, 19 had to be considered as repeatedly false-positive (no clinical evidence of neuroblastoma). Sixteen of 19 parent pairs could be reached by phone and were interviewed separately by use of a semistructured questionnaire to evaluate for psychological consequences resulting from the screening result.

RESULTS

The psychological burden appeared to be small during the initial screening procedure, but it increased significantly through hospital admission and was then described as severe by 19 of the 32 parents.

CONCLUSIONS

Investigators should be aware of the psychological consequences of hospital admission for tumor screening in children. In ongoing neuroblastoma screening studies, laboratory methods as well as cutoff limits should be selected carefully.