Autism spectrum disorder in a child with megalencephaly-capillary malformation-polymicrogyria syndrome (MCAP)

Megalencephaly-capillary malformation-polymicrogyria syndrome (MCAP) is a rare disorder that arises as a result of a somatic mosaic mutation in the PIK3CA gene. It characteristically presents with postnatal or congenital megalencephaly, cutaneous capillary malformations, postaxial polydactyly and often segmental or focal body overgrowth. We report a 7-year-old boy with known MCAP who was diagnosed at around 10 months old with a mosaic change in the PIK3CA gene. He was found to have hall-mark clinical signs; macrocephaly and four-limb postaxial polydactyly. Since diagnosis, he has had multiple clinical features, most of which typically present in children with MCAP. He has now been diagnosed with autism spectrum disorder (ASD), demand avoidance and is under assessment for attention deficit hyperactivity disorder. Although some cases have been raised to the M-CM Network, to our knowledge this is the first case of ASD in MCAP to be reported in the literature.

Hepatoid adenocarcinoma of the stomach with PIK3Ca mutation during pregnancy: A case report with molecular profile

ABSTRACT Hepatoid adenocarcinoma is an extremely aggressive special subtype of gastric tumors. It can be lethal as no standard treatment options for this type of gastric cancer exist. Here, we describe a very rare case of a young female on her 21st week of pregnancy who was diagnosed with stage IV hepatoid adenocarcinoma of the stomach with elevated α fetoprotein (AFP) level. Gene mutation analysis performed by next-generation sequencing identified somatic mutations in the PIK3CA gene. Despite the treatment, patient died 2 months after the initial disease presentation. To our best knowledge, this case represents the first report of pregnancy-associated hepatoid gastric adenocarcinoma with the PIK3CA gene mutations, which can provide further clues for the understanding of molecular features of this type of tumor that can reflect biological behavior and may lead to further effective treatment options.

Expanding the Molecular Genetic Spectrum of Bone and Soft Tissue Fibrosarcomas: An Institutional Experience

Introduction. Fibrosarcomas, once comprising the majority of unclassifiable spindle-cell sarcomas, are now regarded as a diagnosis of exclusion. Objectives. Prompted by an index report of neurotrophic receptor tyrosine kinase (NTRK)3 fusion in fibrosarcomas by Yamazaki et al bone/soft tissue tumors diagnosed as fibrosarcoma at our institution were evaluated in an attempt to expand the genetic spectrum of fibrosarcomas and identify therapeutically targetable cases. Methods. Institutional archives were searched for cases diagnosed as “fibrosarcoma” involving bone/soft tissue from 2000 to present. Twenty-one cases meeting inclusion criteria were identified, 10 of which had formalin-fixed paraffin-embedded tissue available for molecular testing. One case, at the submitting clinician's request, underwent outside deoxyribonucleic acid/ribonucleic acid (DNA/RNA) sequencing while the 9 remaining cases underwent in-house next-generation sequencing RNA fusion analysis. Results. At the time of diagnosis the mean age was 54.5 (range 14-88) with a male to female ratio of 1.5:1. Locations included soft tissue of the lower extremity (3), trunk (2), pelvis (2), head (1), upper extremity (1), and bone (1). Of the 10 cases, 1 demonstrated an FNDC3B-PIK3CA gene fusion and 1 demonstrated a BRAF (p.G469A ) mutation and CDKN2A/B loss. Conclusion. In conclusion, our study demonstrated gene fusions in 1 (10%) of 10 fibrosarcomas diagnosed at our institution in the past 20 years, including FNDC3B-PIK3CA gene fusion. Additionally, 1 case harbored BRAF (p.G469A) mutation and CDKN2A/B loss with no evidence of gene fusion. NTRK rearrangements were not detected. The significance of these molecular aberrations is presently unclear and future studies are needed to establish whether these findings carry any clinicopathologic significance.

Analysis of EGFR, KRAS, and PIK3CA gene mutation rates and clinical distribution in patients with different types of lung cancer

Background To analyze and evaluate EGFR, KRAS, and PIK3CA gene mutation rates and clinical distribution in patients with different types of lung cancer Method A total of 221 lung cancer patients treated in our hospital between January 2016 and June 2019 were enrolled. Tissue and whole blood samples were collected and analyzed to determine the mutation status of EGFR, KRAS, and PIK3CA genes. The gene exon mutation rates were determined. Relevant clinical data, such as age, gender, tumor sample type, treatment method, pathologic type, and lung cancer stage were recorded and statistically analyzed. Results The EGFR gene mutation rates in exons E18-E21 were 2.3%, 17.6%, 3.6%, and 20.4%, respectively. E18, E19, and E20 mutations were commonly detected in adenosquamous carcinoma, and E21 mutations were commonly detected in adenocarcinoma. Mutations in exons E18-E21 were frequently detected in patients with lung cancer stages IA, IB, IIA, or IIB, respectively. The KRAS gene mutation rate in lung cancer patients in exon E2 was higher in whole blood and tissue samples than other exon mutations, while the KRAS gene mutation rate in exons E2 and E3 was significantly higher in patients with lung cancer stages IIB and IA, respectively. PIK3CA gene mutations in exons E9 and E20 occurred in patients < 60 years of age. Exon E9-positive mutations were more common in men or patients with squamous cell carcinoma, while exon E20-positive mutations were more common in females. Conclusion The EGFR, KRAS, and PIK3CA gene exon mutation rates differ and were shown to be correlated with different clinical indicators, which have significance in clinical treatment.

Detection of PIK3CA Gene Mutation in Head and Neck Squamous Cell Carcinoma Using Droplet Digital PCR and RT-qPCR

Head and neck squamous cell carcinomas (HNSCC) are the seventh cause of human malignancy with low survival rate due to late diagnosis and treatment. Its etiology is diverse; however genetic factors are significant. The most common mutations in HNSCC were found in the genes: PIK3CA (10–12%), BRCA1 (6%), and BRCA2 (7–9%). In some cases, these biomarkers correlate with recurrences or survival showing a potential of prognostic and predictive value. A total of 113 formalin-fixed paraffin embedded (FFPE) tumor samples were collected from patients with HNSCC (oral cavity: 35 (31.0%); oropharynx: 30 (26.0%); larynx: 48 (43.0%)). We examined PIK3CA H1047R mutation by Real Time PCR (RT-qPCR) and droplet digital PCR (ddPCR). BRCA1 and BRCA2 mutations were analyzed by RT-qPCR while p16 protein expression was assessed by immunohistochemistry. Finally, we identified HPV infection by RT-qPCR. The relationships between genomic alterations and clinical parameters were assessed using the Yates’ corrected Chi-squared test or Fisher’s exact test for nominal variables. Kaplan Meier plots were applied for survival analysis. Our results revealed 9 PIK3CA H1047R mutations detected by ddPCR: 8 of them were negative in RT-qPCR. Due to the use of different methods to test the presence of the PIK3CA gene mutation, different treatment decisions might be made. That is why it is so important to use the most sensitive methods available. We confirmed the usefulness of ddPCR in the PIK3CA mutation assessment in FFPE samples.

Uncovering the differential impact of ESR1 and PIK3CA codon variants on the clinical phenotype of metastatic breast cancer (MBC) through circulating tumor DNA (ctDNA) next-generation sequencing (NGS).

1033 Background: The exposure to endocrine therapy (ET) can induce the onset of ESR1 gene alterations that have an impact on not only treatment resistance but also clinical phenotype. We previously demonstrated the potential of liquid biopsy in describing the metastatic behavior of MBC. The aim of this study was to explore the different clinical phenotype across the main ESR1 and PIK3CA codon variants. Methods: The study retrospectively analyzed a cohort of 501 MBC patients (pts) characterized for ctDNA through NGS before treatment start at Northwestern University (Chicago, IL), Massachusetts General Hospital (Boston, MA), CRO National Cancer Institute (Aviano, IT) and ASUFC Hospital (Udine, IT) between 2014 and 2020. Associations between clinical characteristics and ESR1 and PIK3CA codon variants were explored through logistic regression corrected for sites and ESR1/ PIK3CA status. Survival was tested through Cox regression both for progression-free survival (PFS) and overall survival (OS). Results: Of the total 501 pts, 289 (58%) were diagnosed with hormone-receptor positive (HRpos) MBC, 114 (23%) with HER2-positive MBC, and 93 (19%) with triple-negative MBC. ESR1 mutations were detected in 71 pts (14%) and PIK3CA in 154 pts (31%). The most represented ESR1 gene mutations were found in codons 380 (9%), 536 (23%), 537 (34%), and 538 (34%), while alterations in codons 542 (19%), 545 (21%), and 1047 (60%) were the most common for PIK3CA. As expected, ESR1 mutations were found only in HRpos pts previously exposed to ET (P < 0.001). No significant differences were observed for PIK3CA. After multivariable analysis, ESR1mutations were confirmed as highly associated with liver and bone metastases (OR 3.31, P < 0.001 and OR 5.09, P < 0.001). Moreover, an association with lung (OR 2.07, P = 0.010) was observed in this cohort. After multivariable analysis, codon 537 mutations were associated with bone involvement (OR 12.97, P = 0.014), codon 538 with liver (OR 4.73, P = 0.010), and codon 536 with soft tissue (OR 5.84, P = 0.006) and liver (OR 4.06, P = 0.048). PIK3CA mutations were associated with bone (OR 2.61, P < 0.001) and lung metastases (OR 1.62, P = 0.044). Specifically, codon 1047 mutations were the primary driver (OR 3.14, P = 0.001 and OR 1.97, P = 0.019). In HRpos MBC, baseline mutations in ESR1 codon 537 and 538 had a negative impact on OS (HR 3.73, P < 0.010 and HR 2.99, P < 0.021), while 380 and 536 had a negative impact on PFS (HR 18.98, P < 0.001 and HR 2.60, P = 0.015). No impact was observed across PIK3CA gene variants. Conclusions: This study showed the different tumor biology across ESR1 and PIK3CA gene variants. As novel selective estrogen receptor degraders (SERDS) and PIK3CA inhibitors are gaining momentum as new ET options in MBC, these results highlight the future pivotal role of ctDNA NGS in refining tumor biology characterization.

Multi-Site Tumour Sampling Improves the Detection of Intra-Tumour Heterogeneity in Oral and Oropharyngeal Squamous Cell Carcinoma

Background: Oral squamous cell carcinoma (OSCC) and oropharyngeal squamous cell carcinoma (OPSCC) are very common in head and neck malignancy. Intratumour heterogeneity (ITH) may hamper their responses to treatment. Hence, novel tumour sampling methods that reflect ITH are required. In this study, we investigated the clinical significance of multi-site tumour sampling (MSTS) to detect ITH in OSCC and OPSCC.Methods: One hundred eighty-two paired specimens were sampled by routine sampling (RS) or MSTS, respectively. Histologically, tumour grade, peri-tumoural vascular and lymphatic growth, perineural permeation, tumour necrosis, and muscle invasion were assessed. Immunohistochemically, the positive and average detection rates of P53(mutant), ki67 and CyclinD1 were detected. The exon 9 and exon 20 mutations of PIK3CA gene and the methylation status of the CDKN2A promoter were analysed.Results: Microscopically, the detection rate of perineural permeation, the detection density of peri-tumoural vascular and lymphatic growth, necrosis and muscle invasion in MSTS were significantly more frequent than those in RP (P &lt; 0.05, P &lt; 0.05, P &lt; 0.01, P &lt; 0.01). MSTS resulted in a higher detection rate of P53 (mutant), ki67, and CyclinD1 expression than did RS, but the difference was not significant. MSTS's detection rates in PIK3CA gene mutation and gene methylation sequencing in CDKN2A gene promoter region were both higher than RP (P &lt; 0.05, P &lt; 0.01). To be emphasised, the hotspot mutation H1047Rwas detected in one MSTS specimen (case 24M5) but in no RS specimens.Conclusions: This study verified that MSTS's advantage in the reflection of morphological and molecular characteristics of OSCC and OPSCC. MSTS was more representative than RP. Therefore, MSTS can compensate the RP limitations in ITH detection especially in large tumours.

Successful Use of Intragastric Dextrose in a Unique Presentation of Congenital Hyperinsulinism

Introduction: Congenital hyperinsulinism (HI) is the most common cause of persistent hypoglycemia in infants and can pose challenges if unresponsive to diazoxide. HI can be caused by monogenic mutations or can be associated with genetic syndromes. Macrocephaly Capillary malformation (MCAP) is a rare overgrowth syndrome, caused by heterozygous variants in the PIK3CA gene. A small number of pathologic variants in this gene have been reported to cause HI. Clinical Case: A 4-month-old boy presented with a hypoglycemic seizure while fasting for an MRI. His history was notable for being born LGA and having macrocephaly, segmental infantile hemangioma, and ventriculomegaly requiring VP shunt. Critical labs were consistent with HI: plasma glucose (PG) of 23 mg/dL (54-117), inappropriately detectable insulin (2.7 mIU/mL) and c-peptide (1.6 ng/mL), low beta hydroxybutyrate (0.1 mmol/L) and low free fatty acids (0.16 mmol/L), and a positive glucagon stimulation test (increase in PG from 48 to 101 mg/dL in 30 minutes). Diazoxide was started at 5 mg/kg/day and titrated to 15 mg/kg/day, but he was unable to maintain PG &gt;70 mg/dL. He was deemed unresponsive and the diazoxide was discontinued. His intravenous glucose infusion rate (GIR) was 14.4 mg/kg/min. An octreotide trial (8 mcg/kg/day) revealed a robust response: PG 64 mg/dL before initial dose, 105 mg/dL 3 hours later. However, he developed tachyphylaxis to the octreotide and it was discontinued. To further evaluate the etiology of his HI, he underwent an 18F-DOPA PET scan, which showed diffuse uptake. Genetic sequencing for the 9 known HI genes was negative. At 6-months-old, he was evaluated by genetics who based on his clinical features diagnosed him with MCAP. After failure of diazoxide and octreotide therapies, he was slowly transitioned from IV dextrose to continuous intragastric dextrose (IGD) using D20W. He was managed with a GIR of 10 mg/kg/min during the day (while receiving bolus feeds) and 5 mg/kg/min while on continuous feeds overnight. The continuous IGD allowed him to maintain euglycemia and develop his oral feeding skills. By 17-months-old, feeds by mouth improved and GIR had decreased to 6.5 mg/kg/min during the day and 2.5 mg/kg/min overnight. Genetic analysis eventually revealed a heterozygous p.Glu365Lys (c.1093 G&gt;A) variant in the PIK3CA gene as the likely cause of the HI. Conclusion: Genetic syndromes should be considered in infants with persistent hyperinsulinism and multiple congenital anomalies. Clinical work-up may provide important clues to the diagnosis. Diazoxide unresponsive HI can be treated with continuous IGD to prevent hypoglycemia-induced brain damage. Continuous IGD likely leads to better oral skills and decreased oral aversion compared to using continuous formula feeds.