Background

Intra-operative tumor spill increases the risk of local recurrence of Wilms tumor, and adversely impacts relapse-free (RFS) and overall survival (OS) rates.

Methods

Surgical checklists, operative notes, institutional pathology reports, central pathology review and flow sheets of 602 patients registered between August 1986 and September 1994 on National Wilms Tumor Study-4 as randomized, followed or switched and coded as Final Stage II, favorable histology (FH) were reviewed. RFS and OS were estimated using the Kaplan-Meier method. Hazard ratios (HRs) were estimated using the Cox model and tested for statistical significance by the log-rank test.

Results

Four hundred ninety-nine patients were found after review to have Stage II, FH Wilms tumor. The 8-year RFS percentages were 85.0% (95% confidence interval (CI): 81.1%, 88.1%) for those with no spill compared to 75.7% (65.8%, 83.2%) for those with spill. The 8-year OS percentages were 95.6% (93.1%, 97.3%) for those with no spill compared to 90.3% (82.2%, 94.9%) for those with spill. The HR for relapse among those with spill was 1.55 ((95%CI: 0.97,2.51), P = 0.067) and the HR for death was 1.94 ((0.92,4.09), P = 0.077).

Conclusions

RFS and OS were lower for patients who had intra-operative tumor spill. The majority of NWTS Stage II, FH patients with intra-operative tumor spill have an overall excellent outcome when treated with two drug chemotherapy (vincristine and actinomycin D) and no abdominal irradiation.

Purpose

The use of computed tomography (CT) for routine surveillance to detect recurrence in patients with Wilms tumor (WT) has increased in recent years. The utility of CT, despite increased risk and cost, to improve outcome for these patients is unknown. We conducted a retrospective analysis with patients enrolled in the fifth National Wilms Tumor Study (NWTS-5) to determine if surveillance with CT correlates with improved overall survival (OS) after recurrence compared with chest x-ray (CXR) and abdominal ultrasound (US).

Patients and methods

Overall, 281 patients with recurrent unilateral favorable-histology WT were reviewed to assess how WT recurrence was detected: sign/symptoms (SS), surveillance imaging (SI) with CT scan, or SI with CXR/US.

Results

The estimated 5-year OS rate after relapse was 67% (95% CI, 61% to 72%). Twenty-five percent of recurrences were detected with SS; 48.5%, with CXR/US; and 26.5%, with CT. Patients with SS had a 5-year OS rate of 59% (95% CI, 46% to 72%) compared with 70% (95% CI, 63% to 77%; P = .23) for those detected by SI. Recurrences detected by CT had a shorter median time from diagnosis to recurrence (0.60 years) compared with SS (0.91 years) or CXR/US (0.86 years; P = .003). For recurrences detected by SI, more tumor foci at relapse ( P < .001) and size of the largest focus greater than 2 cm ( P = .02) were associated with inferior OS. However, there was no difference in OS after relapse when recurrence was detected by CT versus CXR/US (5-year OS rate, 65% v 73%; P = .20).

Conclusion

In patients with favorable-histology WT, elimination of CT scans from surveillance programs is unlikely to compromise survival but would result in substantial reduction in radiation exposure and health care costs.

Purpose The National Wilms Tumor Study (NWTS) treatment of favorable histology Wilms tumor with lung metastases was vincristine/dactinomycin/doxorubicin (DD4A) and lung radiation therapy (RT). The AREN0533 study applied a new risk stratification and treatment strategy to improve event-free survival (EFS) while reducing exposure to lung RT. Methods Patients with favorable histology Wilms tumor and isolated lung metastases showing complete lung nodule response (CR) after 6 weeks of DD4A continued receiving chemotherapy without lung RT. Patients with incomplete response (IR) or loss of heterozygosity at chromosomes 1p/16q received lung RT and four cycles of cyclophosphamide/etoposide in addition to DD4A drugs (Regimen M). AREN0533 was designed to preserve a 4-year EFS of 85% for lung nodule CR and improve 4-year EFS from 75% to 85% for lung nodule IR. Results Among 292 assessable patients, 133 had CR and 159 had IR. For patients with CR, 4-year EFS and overall survival (OS) estimates were 79.5% (95% CI, 71.2% to 87.8%) and 96.1% (95% CI, 92.1% to 100%), respectively. Expected versus observed event rates were 15% and 20.2% ( P = .052), respectively. For patients with IR, 4-year EFS and OS estimates were 88.5% (95% CI, 81.8% to 95.3%) and 95.4% (95% CI, 90.9% to 99.8%), respectively. Expected versus observed event rates were 25% and 12.2% ( P < .001), respectively. Overall, 4-year EFS and OS were 85.4% (95% CI, 80.5% to 90.2%) and 95.6% (95% CI, 92.8% to 98.4%) compared with 72.5% (95% CI, 66.9% to 78.1%; P < .001) and 84.0% (95% CI, 79.4% to 88.6%; P < .001), respectively, in the predecessor NWTS-5 study. Conclusion Excellent OS was achieved after omission of primary lung RT in patients with lung nodule CR, although there were more events than expected. EFS was significantly improved, with excellent OS, in patients with lung nodule IR using four cycles of cyclophosphamide/etoposide in addition to DD4A drugs. The overall AREN0533 treatment strategy yielded EFS and OS estimates that were superior to previous studies.

Purpose

In National Wilms Tumor Study 5 (NWTS-5), tumor-specific combined loss of heterozygosity of chromosomes 1p and 16q (LOH1p/16q) was associated with adverse outcomes in patients with favorable histology Wilms tumor. The AREN0533/AREN0532 studies assessed whether augmenting therapy improved event-free survival (EFS) for these patients. Patients with stage I/II disease received regimen DD4A (vincristine, dactinomycin and doxorubicin) but no radiation therapy. Patients with stage III/IV disease received regimen M (vincristine, dactinomycin, and doxorubicin alternating with cyclophosphamide and etoposide) and radiation therapy.

Methods

Patients were enrolled through the AREN03B2 Biology study between October 2006 and October 2013; all underwent central review of pathology, surgical reports, and imaging. Tumors were evaluated for LOH1p/16q by microsatellite testing. EFS and overall survival were compared using the log-rank test between NWTS-5 and current studies.

Results

LOH1p/16q was detected in 49 of 1,147 evaluable patients with stage I/II disease (4.27%) enrolled in AREN03B2; 32 enrolled in AREN0532. LOH1p/16q was detected in 82 of 1,364 evaluable patients with stage III/IV disease (6.01%) in AREN03B2; 51 enrolled in AREN0533. Median follow-up for 83 eligible patients enrolled in AREN0532/0533 was 5.73 years (range, 2.84 to 9.63 years). The 4-year EFS for patients with stage I/II and stage III/IV disease with LOH1p/16 was 87.3% (95% CI, 75.1% to 99.5%) and 90.2% (95% CI, 81.8% to 98.6%), respectively. These results are improved compared with the NWTS-5 updated 4-year EFS of 68.8% for patients with stage I/II disease (P = .042), and 61.3% for patients with stage III/IV disease (P = .001), with trends toward improved 4-year overall survival. The most common grade 3 or higher nonhematologic toxicities with regimen M were febrile neutropenia (39.2%) and infections (21.6%).

Conclusion

Augmentation of therapy improved EFS for patients with favorable histology Wilms tumor and LOH1p/16q compared with the historical NWTS-5 comparison group, with an expected toxicity profile.