Surgical treatment of neuroblastoma with micrometastasis

A comprehensive overview of liquid biopsy applications in pediatric solid tumors

Liquid biopsies are emerging as an alternative source for pediatric cancer biomarkers with potential applications during all stages of patient care, from diagnosis to long-term follow-up. While developments within this field are reported, these mainly focus on dedicated items such as a specific liquid biopsy matrix, analyte, and/or single tumor type. To the best of our knowledge, a comprehensive overview is lacking. Here, we review the current state of liquid biopsy research for the most common non-central nervous system pediatric solid tumors. These include neuroblastoma, renal tumors, germ cell tumors, osteosarcoma, Ewing sarcoma, rhabdomyosarcoma and other soft tissue sarcomas, and liver tumors. Within this selection, we discuss the most important or recent studies involving liquid biopsy-based biomarkers, anticipated clinical applications, and the current challenges for success. Furthermore, we provide an overview of liquid biopsy-based biomarker publication output for each tumor type based on a comprehensive literature search between 1989 and 2023. Per study identified, we list the relevant liquid biopsy-based biomarkers, matrices (e.g., peripheral blood, bone marrow, or cerebrospinal fluid), analytes (e.g., circulating cell-free and tumor DNA, microRNAs, and circulating tumor cells), methods (e.g., digital droplet PCR and next-generation sequencing), the involved pediatric patient cohort, and proposed applications. As such, we identified 344 unique publications. Taken together, while the liquid biopsy field in pediatric oncology is still behind adult oncology, potentially relevant publications have increased over the last decade. Importantly, steps towards clinical implementation are rapidly gaining ground, notably through validation of liquid biopsy-based biomarkers in pediatric clinical trials.

Opportunities and challenges of circulating biomarkers in neuroblastoma

Molecular analysis of nucleic acid and protein biomarkers is becoming increasingly common in paediatric oncology for diagnosis, risk stratification and molecularly targeted therapeutics. However, many current and emerging biomarkers are based on analysis of tumour tissue, which is obtained through invasive surgical procedures and in some cases may not be accessible. Over the past decade, there has been growing interest in the utility of circulating biomarkers such as cell-free nucleic acids, circulating tumour cells and extracellular vesicles as a so-called liquid biopsy of cancer. Here, we review the potential of emerging circulating biomarkers in the management of neuroblastoma and highlight challenges to their implementation in the clinic.

Value of surgical resection in children with high-risk neuroblastoma

BACKGROUND

The value of gross total resection (GTR) for children with high-risk neuroblastoma (NB) is controversial. We hypothesized that patients undergoing GTR would demonstrate improved overall survival (OS) compared those having <GTR.

METHODS

Using a single institutional database, we reviewed the medical records of all children with high-risk NB undergoing hematopoietic stem cell transplantation (HSCT) as part of multimodality therapy from 1990 to 2012. Children had received surgical care at multiple institutions (n = 14) prior to HSCT and were divided into two groups based on extent of surgical resection: GTR (no visible or palpable disease at end of operation) and <GTR (no surgery, biopsy only, or subtotal resection). Kaplan-Meier curves and Cox hazards models evaluated differences in overall survival (OS).

RESULTS

One hundred four children underwent HSCT, and 87 (83.6%) had adequate data for analysis. Thirty eight percent had GTR while 62% had <GTR prior to HSCT. There was no significant difference in OS in patients undergoing GTR compared to <GTR (Log rank test: P = 0.49). Post-hoc analysis demonstrated a survival advantage for patients undergoing >90% resection compared to <90% resection (P = 0.008). Multivariable Cox models confirmed these findings with improved survival in children undergoing >90% vs. <90% resection but no difference in GTR vs. <GTR.

CONCLUSION

Gross total resection prior to HSCT in high-risk NB patients is not associated with improved OS compared to <GTR; however, these results suggest that >90% resection is associated with improved OS compared to less than 90% resection.

Excellent local tumor control regardless of extent of surgical resection after treatment on the Chicago Pilot II protocol for neuroblastoma

BACKGROUND

Our aim was to investigate the impact of the extent of surgical resection on local recurrence and survival in high-risk patients treated with the Chicago Pilot II protocol.

METHODS

Retrospective chart review was performed on 30 patients enrolled in the Chicago Pilot II protocol between 1995 and 2003. Variables studied were location of tumor, extent of resection, timing and location of recurrence, MYCN amplification, surgical complications, event-free survival, and overall survival (OS). Operative reports and postoperative meta-iodobenzylguanidine scans were used to assess extent of resection. Complete resection (CR) was defined as no gross residual tumor including primary and nodal disease.

RESULTS

Three-year event-free survival and OS of this cohort of 30 patients was 58% and 82%, respectively. Only 1 patient developed a local recurrence, whereas metastatic recurrent disease was observed in 13 (43%) of the 30; and this subset had a significantly worse OS (23% vs 94%, P = .001). The most common relapse location was in bone. Patients with incomplete resection (IR) (11/30) and CR (19/30) had recurrence rates of 64% (7/11) and 32% (6/19, P = .12), respectively. Event-free survival was significantly better for patients with CR (68%) vs IR (27%; P = .05; odds ratio, 2.9). Overall survival rates for patients with CR vs IR were 68% vs 55%, respectively (P = .25).

CONCLUSIONS

Recurrence rate was the significant determinant of survival. Patients with CR had lower recurrence rates; however, they did not have improved local control. Final outcome of patients with unfavorable neuroblastoma will be determined by metastatic recurrence, not by extent of resection.

Tumor cell dynamics and metastasis in advanced neuroblastoma

This study deals with the advancement process of neuroblastoma through clinical observations and circulating tumor cell exploration. Clinical feature, tumor biology, and circulating tumor cell detected by the previously described polymerase chain reaction (PCR) method were analyzed in 31 patients with advanced neuroblastoma treated in our department since 1991 through 2004. Treatment was completed in 28 patients, of whom 17 are alive without the disease and 11 died. The primary lesion was not confirmed in 2 patients with disseminated metastasis, both of whom showed positive circulating tumor cell. Circulating tumor cell was positive in 6 of 9 examined at their first appearance at the hospital, all had stage 4 disease, and 4 of the 6 (66.7%) died of systemic spread of the disease. N-myc was amplified in 15 patients, of whom only 2 (13.3%) died of systemic metastasis. N-myc amplification did not correlate with positive circulating tumor cell. A certain population of neuroblastoma may provide circulating tumor cells from the early period of the disease to form metastatic lesions independently of the primary lesion, which must be regulated by factors other than N-myc. Circulating tumor cells may suggest higher risk for systemic dissemination and poor prognosis.

The impact of gross total resection on local control and survival in high-risk neuroblastoma

BACKGROUND/PURPOSE

Gross total resection of the primary tumor in treatment of high-risk neuroblastoma remains controversial. Furthermore, there are few reports of the effect of primary tumor resection on local control as opposed to overall survival. The authors reviewed their institutional experience to assess the effect of primary tumor resection on local control and overall survival.

METHODS

A total of 141 patients were treated on protocol between November 1, 1979 and June 25, 2002 and are the subject of this report. Gross total resection was assessed by review of operative notes, postoperative computerized axial tomograms, and postoperative meta-iodobenzyl guanidine (MIBG)1 scans when available.

RESULTS

The median age was 3.3 years, and all patients were International Neuroblastoma Staging System (INSS) stage 4 with 79% having metastases to cortical bone. The primary site was the adrenal gland in 74%, the central abdominal compartment in 13%, the posterior mediastinum in 7%, and other sites in 6%. Gross total resection was accomplished in 103 (73%) but was more than 90% for the last 3 protocols. Five kidneys were lost overall. The probability of local progression was 50% in unresected patients compared with 10% in patients undergoing gross total resection (P <.01). Overall survival rate in resected patients was 50% compared with 11% in unresected patients (P <.01).

CONCLUSIONS

Our data indicate that local control and overall survival rate are correlated with gross total resection of the primary tumor in high-risk neuroblastoma. Gross total resection should be part of the management of stage 4 neuroblastoma in patients greater than 1 year of age.

Clinical significance of intensive surgery with intraoperative radiation for advanced neuroblastoma: does it really make sense?

PURPOSE

The aim of this study was to evaluate the significance of intensive surgery combined with intraoperative radiation therapy (IORT) in advanced neuroblastoma.

METHODS

Clinical features and outcome were reviewed in 33 advanced neuroblastoma patients (24 with INSS stage 4, 9 with stage 3), who had surgery (total excision 29, subtotal excision 4) with IORT (10 to 15 Gy) against the primary tumor site.

RESULTS

Three patients (8.8%) had relapse at the primary site, all of which arose from the unirradiated area after stem cell transplantation. Among 29 patients with total excision, disease-free survival was obtained in 15 (51.7%) for an average of 6.9 years, which included 5 survivors of 9 patients (55.9%) with amplified N-myc. In contrast, none of 4 patients with macroscopic residual survived. The Kaplan-Meier analysis showed significantly longer survival rates in the patients with total resection compared with those with macroscopic remnants.

CONCLUSIONS

The intensive surgery with IORT dramatically increased the local eradication and improved the outcome even in advanced neuroblastoma with N-myc amplification. However, long-term survival was not obtained in patients with unresectable residual disease. These results may indicate the key role of surgical eradication in advanced neuroblastoma.