Rescue intra-arterial chemotherapy in unilateral multirelapsed peripapillary retinoblastoma: Decision making and the role of MRI

Introduction:

In this case report we report our experience with rescue intra-arterial chemotherapy in a case of multi-relapsed peripapillary Retinoblastoma (RB) and the importance of high resolution MRI in detecting possible optic disc infiltration.

Case report:

In 2007, a 14 month-old caucasian girl was referred to our ocular oncology unit for leukocoria. Only left eye was interested, with a single mass of the posterior pole. Patient underwent six cycles of systemic chemotherapy and focal laser consolidation. Several relapses occurred during follow-up. Selective intra-arterial chemotherapy (SIAC) with Melphalan was performed and type IV remission was achieved. A new relapse occurred next to the optic disc. MRI was performed and we decided to try to save the globe with a rescue cycle of SIAC.

Conclusion:

MRI has demonstrated to be useful in decision making in RB, giving us a last chance to save the globe.

Two-point-NGS analysis of cancer genes in cell-free DNA of metastatic cancer patients

BACKGROUND

Although the efficacy of molecularly target agents in vitro, their use in routine setting is limited mainly to the use of anti-HER2 and antiEGFR agents in vivo. Moreover, core biopsy of a single cancer site may not be representative of the whole expanding clones and cancer molecular profile at relapse may differ with respect to the primary tumor.

METHODS

We assessed the status of a large panel of cancer driver genes by cell-free DNA (cfDNA) analysis in a cohort of 68 patients with 13 different solid tumors at disease progression. Whenever possible, a second cfDNA analysis was performed after a mean of 2.5 months, in order to confirm the identified clone(s) and to check the correlation with clinical evolution.

RESULTS

The approach was able to identify clones plausibly involved in the disease progression mechanism in about 65% of cases. A mean of 1.4 mutated genes (range 1-3) for each tumor was found. Point mutations in TP53, PIK3CA, and KRAS and copy number variations in FGFR3 were the gene alterations more commonly observed, with a rate of 48%, 20%, 16%, and 20%, respectively. Two-points-Next-Generation Sequencing (NGS) analysis demonstrated statistically significant correlation between allele frequency variation and clinical outcome (P = .026).

CONCLUSIONS

Irrespective of the primary tumor mutational burden, few mutated genes are present at disease progression. Clinical outcome is consistent with variation of allele frequency of specific clones indicating that cfDNA two-point-NGS analysis of cancer driver genes could be an efficacy tool for precision oncology.

Specific clonal expansion at disease progression (PD) in solid cancers pinpointed by cell free DNA analysis

e13144

Background: More than 50% of solid cancers sooner or later escape control of standard treatments. Detection and analysis of cell free circulating DNA (cfDNA) now offer the possibility to detect key mutations of cancer driver genes which may play a major role in the therapy escaping mechanism. We sought to identify clones of solid tumors escaping standard treatments in order to assess personalized treatment at PD. Methods: A cohort of patients with 10 different solid tumors progressing after standard therapy were selected. CfDNA analysis was performed using PAXgene blood ccfDNA tubes (QIAGEN), MagMAX cell-free total nucleic acid isolation kit, and ION PROTON platform (ThermoFisher Scientific). Results: Next generation sequencing analysis of 52 cancer-driver genes of cfDNA samples of 39 patients allowed for picking up clones plausibly involved in the PD mechanism in 60% of cases. A mean of 1.3 mutated genes (range 1-3) for each tumor was found. Point mutations in TP53, PIK3CA, and CNV in FGFR3 were the most commonly observed, with a rate of 41%, 16%, and 13%, respectively. Increased copy number variations of FGF receptors were identified in patients with non-small cell lung, pancreatic, and gastric cancer, and cholangiocarcinoma. Other clones had mutations in ESR1 (breast), CTNNB1 (uterus), KRAS and CCND2 (pancreas), EGFR and BRAF (lung). Interestingly, retinoblastomas resistant to Melphalan showed expanding mutated clones in PTEN or SMAD4. Increased levels of cfDNA were observed in the plasma of all patients. Conclusions: The results presented here show that irrespective of the primary tumor mutational burden and subsequent complex clonal evolution, a simplified mutational load is present at PD. One or few “sniper” clones drive progression and the molecular profile has a weak correlation with the primary tumor. Single driver mutations in TP53 remain the main target of a not yet developed specific therapy in most tumors such as breast, ovarian, uterine, lung, gastric cancers and glioblastoma. Among the actionable mutations, PIK3CA were found, not only in breast cancers, but also in uterine carcinoma, Sezary syndrome and glioblastoma, pinpointing the needs of specific trials in these tumors.