Localized infant neuroblastomas often show spontaneous regression: results of the prospective trials NB95-S and NB97

PURPOSE

The excellent prognosis of localized neuroblastoma in infants, the overdiagnosis observed in neuroblastoma screening studies, and several case reports of regression of localized neuroblastoma prompted us to initiate a prospective cooperative trial on observation of localized neuroblastoma without cytotoxic treatment.

PATIENTS AND METHODS

For infants with localized neuroblastoma without MYCN amplification, chemotherapy was scheduled only in cases with threatening symptoms; otherwise, the tumor was either resected or observed by ultrasound and magnetic resonance imaging (MRI).

RESULTS

Of 340 eligible participants, 190 underwent resection, 57 were treated with chemotherapy, and 93 were observed with gross residual tumor. Of those 93 patients with unresected tumors, spontaneous regression was seen in 44, local progression in 28, progression to stage 4S in seven, and progression to stage 4 in four. Time to regression was quite variable, with first signs of regression noted 1 to 18 months after diagnosis and in 15 of 44 patients even after the first year of life. So far, complete regression was observed in 17 of 44 patients 4 to 20 months after diagnosis. Known clinical risk factors were not able to differentiate between patients with regression and regional or metastatic progression. Overall survival (OS; 3-year OS, 0.99 +/- 0.01) and metastases-free survival (rate at 3 years, 0.94 +/- 0.03) for patients with unresected tumors was excellent and was not different from patients treated with surgery or chemotherapy.

CONCLUSION

Spontaneous regression is regularly seen in infants with localized neuroblastoma and is not limited to the first year of life. A wait-and-see strategy is justified in those patients.

Results for 79 patients with neuroblastoma detected through mass screening at 6 months of age in a single institute

BACKGROUND

In Japan, mass screening for neuroblastoma has been performed at 6 months of age to improve the prognosis of this condition for more than 20 years. In recent years, most neuroblastomas detected by mass screening were considered to have favorable biological features and sometimes tend to regress spontaneously.

METHODS

The authors established non-treated observation criteria in 1997 and criteria for observation of residual tumor after first-line chemotherapy in 1999, and have made an effort to reduce the intensity of medical treatment for neuroblastoma. The authors examined outcomes of 79 patients who were found in the Shizuoka neuroblastoma mass screening at 6 months of age and who received medical treatment or underwent observation in Shizuoka Children's Hospital, Shizuoka, Japan, between December 1981 and December 2004.

RESULTS

A total of 77 patients survived but the remaining two patients died from complications of medical treatment. None of the patients died due to progression of neuroblastoma. In the cases, non-treated observation was performed in 17. Of those, 12 patients are now under non-treated observation. Of their tumors, two have disappeared, nine have become smaller and another one has not change in size. Observation of residual tumor after first-line chemotherapy was performed in 15 cases, and three disappeared and the other 12 cases became smaller. Medical treatment-related complications were observed in 20 of 67 patients who received medical treatment, and 18 of the 20 patients were seen before establishing non-treated observation criteria.

CONCLUSION

Non-treated observation and observation of residual tumor after first-line chemotherapy were useful to reduce medical treatment-related complications.

Survival of children with neuroblastoma. time trends and regional differences in Europe, 1978--1992

Neuroblastoma is one of the most common solid cancers in children. We present the data collected for the EUROCARE II study, describing survival patterns for children diagnosed in Europe 1985--1989 in detail, and exploring time trends from 1978 to 1992. On average, the mean 5-year survival rate was considerably higher in infants (79%) compared with older children (30--33%). The risk of death has dropped by 37% from 1978--1981 to 1990--1992. There is a pronounced difference between countries, with Scotland and England and Wales having two of the lowest survival rates (28% (95% confidence interval (CI) 14--48) and 36% (95% CI 31--41) 5-year survival rates, respectively). The survival rates in France, Germany and Italy (48--66% 5-year survival rate) were among the highest. This pattern corresponds to the incidence rates for these countries. It can be assumed that in neuroblastoma, both incidence and survival are related to the frequency of diagnosing asymptomatic cases with good prognosis among infants. However, one cannot ignore possible intercountry differences in the effectiveness of therapy.

Neuroblastoma in the neonate

Neuroblastoma is the most common malignant neoplasm occurring in the neonate and arguably the most variable in its presentation. This review examines differences in the tumor's clinical course in the context of known biologic determinants of behavior. Tumors that would go undetected except for prenatal ultrasonography or postnatal neuroblastoma screening characteristically undergo spontaneous regression or maturation and require little or no treatment. Most low stage tumors with favorable biological features are effectively treated with surgery alone. The more bulky locoregional (stage 3) tumors require chemotherapy in addition to surgery. The most challenging tumors are those that are disseminated at birth (stages 4 and 4S). Management plans for these tumors are based on the biological characteristics of the tumor and (in the case of stage 4S tumors) on the presence and extent of functional embarrassment of vital organs.