Retrospective and integrative analyses of molecular characteristics and their specific imaging parameters in pediatric grade 1 gliomas.

BACKGROUND: Pediatric low-grade gliomas (PLGG) are the most common brain tumors diagnosed during childhood and represent a heterogeneous group associating variable molecular abnormalities. To go further and develop specific statistical patterns between tumor molecular background, imaging features, and patient outcome, a retrospective study was performed in a group of non-neurofibromatosis type 1 (non-NF1) grade 1 PLGGs. PATIENTS AND METHODS: Seventy-eight children, followed from 2004 to 2017, were retrospectively reported. In this population, we analyzed radiological and molecular parameters. Their therapeutic management comprised surgery or surgery plus chemotherapies. RESULTS: Considering all 78 patients, 59 had only a surgical removal and 19 patients were treated with postoperative chemotherapy. Twelve progressions were reported in the partially resected and chemotherapeutic groups, whereas four deaths occurred only in the highly treated patients. As expected, in the global cohort, PLGG with BRAF p.V600E and/or CDKN2A loss exhibited poor outcomes and we evidenced significant associations between those molecular characteristics and their imaging presentation. In the chemo-treated patients, when associating initial and 6-month magnetic resonance imaging (MRI) parameters to the molecular features, the good risk situations were significantly linked to the presence of a large tumor cyst at diagnosis and the appearance during treatment of a higher cystic proportion that we called cystic conversion. CONCLUSION: So, additionally to the presence of BRAF p.V600E or CDKN2A deletion in grade 1 PLGGs, the absence on diagnostic MRI of cystic parts and/or cystic conversion at 6-month chemotherapy were significantly linked to a worst prognosis and response to treatment. These imaging features should be considered as prognostic markers in future PLGG studies.

Second malignant neoplasm occurring years after hyperthermic isolated limb perfusion for melanoma.

BACKGROUND: Hyperthermic isolated limb perfusion (HILP) is a useful therapeutic option in patients with locally advanced melanoma of the extremities. Because HILP allows very high doses of cytotoxic agents to be administered without systemic leakage, the theoretical risk of a secondary malignant neoplasm is real, particularly in the treated limb. Such an event has never been reported to our knowledge, however, possibly in part because survival in these patients is often too short to permit the development of chemo-induced cancers. OBSERVATIONS: We describe 2 cases of secondary rare cancers in 2 elderly women: 1 fatal pleomorphic sarcoma and 1 Merkel cell carcinoma, which developed on the same limb 16 years after HILP for melanoma. The first patient had an exceptional prolonged complete response after HILP for unresectable regional metastases, while the second had been overtreated with HILP and dacarbazine in an adjuvant setting for an early-stage melanoma. CONCLUSIONS: Because long-term survivors of regionally advanced melanoma, although rare, do exist, candidates for HILP should be warned of the risk of long-term development of nonmelanoma secondary cancers. The risk-benefit balance of high-dose local chemotherapy should be carefully evaluated in the light of these findings, especially in patients with early-stage melanoma or other non-life-threatening medical conditions.