Background PIK3CA-related overgrowth spectrum (PROS) include a group of disorders that affect only the terminal portion of a limb, such as type I macrodactyly, and conditions like fibroadipose overgrowth (FAO), megalencephaly-capillary malformation (MCAP) syndrome, congenital lipomatous asymmetric overgrowth of the trunk, lymphatic, capillary, venous, and combined-type vascular malformations, epidermal nevi, skeletal and spinal anomalies (CLOVES) syndrome and Hemihyperplasia Multiple Lipomatosis (HHML). Heterozygous postzygotic PIK3CA mutations are frequently identified in these syndromes, while timing and tissue specificity of the mutational event are likely responsible for the extreme phenotypic variability observed.MethodsWe carried out a combination of Sanger sequencing and targeted deep sequencing of genes involved in the PI3K/AKT/mTOR pathway in three patients (1 MCAP and 2 FAO) to identify causative mutations, and performed immunoblot analyses to assay the phosphorylation status of AKT and P70S6K in affected dermal fibroblasts. In addition, we evaluated their ability to grow in the absence of serum and their response to the PI3K inhibitors wortmannin and LY294002 in vitro.Results and ConclusionOur data indicate that patients’ cells showed constitutive activation of the PI3K/Akt pathway. Of note, PI3K pharmacological blockade resulted in a significant reduction of the proliferation rate in culture, suggesting that inhibition of PI3K might prove beneficial in future therapies for PROS patients.

Neurofibromatosis type 1 (NF1) is one of the most common autosomal dominant genetic diseases. It is caused by mutations in the NF1 gene encoding for the large protein, neurofibromin. Genetic testing of NF1 is cumbersome because 50% of cases are sporadic, and there are no mutation hot spots. In addition, the most recognizable NF1 clinical features—café-au-lait (CALs) spots and axillary and/or inguinal freckling—appear early in childhood but are rather non-specific. Thus, the identification of causative variants is extremely important for early diagnosis, especially in paediatric patients. Here, we aimed to identify the underlying genetic defects in 72 index patients referred to our centre for NF1. Causative mutations were identified in 58 subjects, with 29 being novel changes. We evaluated missense and non-canonical splicing mutations with both protein and splicing prediction algorithms. The ratio of splicing mutations detected was higher than that reported in recent patients’ series and in the Human Gene Mutation Database (HGMD). After applying in silico predictive tools to 41 previously reported missense variants, we demonstrated that 46.3% of these putatively missense mutations were forecasted to alter splicing instead. Our data suggest that mutations affecting splicing can be frequently underscored if not analysed in depth. We confirm that hamartomas can be useful for diagnosing NF1 in children. Lisch nodules and cutaneous neurofibromas were more frequent in patients with frameshifting mutations. In conclusion, we demonstrated that comprehensive in silico analysis can be a highly specific method for predicting the nature of NF1 mutations and may help in assuring proper patient care.

Molecular testing for KRAS and BRAF mutations in tumor tissue is a fundamental tool to identify patients with metastatic colorectal cancer (CRC) who are eligible for anti-EGFR monoclonal antibody therapy. We here report a molecular analysis by high-resolution melting analysis and direct sequencing of KRAS, BRAF and PIK3CA hot spot mutations in 209 Italian CRC patients. One hundred and ten patients (51%) were identified who were potentially nonresponders to anti-EGFR therapy: 90/209 patients (43%) harboring KRAS mutations, 13/117 (11.1%) with the V600E BRAF mutation, and 7/209 (3.3%) with mutations in PIK3CA exon 20. The prevalence of BRAF and PIK3CA mutations was significantly higher in patients older than 65 years (p=0.014 and p=0.018), while patients with triple-negative tumors were significantly younger than mutation carriers (p=0.000011). Patients with gene mutations also showed a trend towards preferential tumor location in the colon (p=0.026). Moreover, although involving a relatively small number of samples, we report the presence of a discordant mutational profile between primary tumors and secondary lesions (3/9 patients), suggesting that it is worthwhile to test other available tissues in order to better define the efficacy of targeted therapy. Further correlations of specific clinical features with tumor mutational profile could be helpful to predict the response of CRC patients to monoclonal antibody therapy.

Background and aim The BRCA 1 and BRCA 2 genes are associated with an inherited susceptibility to breast cancer with a cumulative risk of 60% in BRCA 1 mutation carriers and of 30% in BRCA 2 mutation carriers. Several lifestyle factors could play a role in determining an individual’s risk of breast cancer. Obesity, changes in body size or unhealthy lifestyle habits such as smoking, alcohol consumption and physical inactivity have been evaluated as possible determinants of breast cancer risk. The aim of this study was to explore the current understanding of the role of harmful lifestyle and obesity or weight change in the development of breast cancer in female carriers of BRCA 1/2 mutations. Methods Articles were identified from MEDLINE in October 2020 utilizing related keywords; they were then read and notes, study participants, measures, data analysis and results were used to write this review. Results Studies with very large case series have been carried out but only few of them have shown consistent results. Additional research would be beneficial to better determine the actual role and impact of such factors.

Background: Environmental factors may influence the lifetime risk of cancer (penetrance) in women with a BRCA mutation. Materials and Methods: In 89 BRCA-mutant women, affected or unaffected by breast/ovarian cancer, we explored serum levels of adipokines and their relation with the polymorphism SNP276G>T as modulators of BRCA penetrance. Results: Affected women had significantly lower adiponectin than healthy women. Affected women with rs1501299 TT had significantly lower adiponectin and higher leptin than GT and GG genotypes. GT genotype was significantly associated with the disease status [odds ratio (OR)=3.24, 95% confidence interval (95% CI)=1.03-10.17]. Women in the lower tertile of serum adiponectin had a RR of BRCA-associated cancer of 2.80, 95% CI=1.1-7.1 (p for trend=0.03) compared with women in the higher tertile. Conclusion: In the SNP rs1501299 the T allele was significantly associated with lower serum levels of adiponectin in affected women, suggesting that the T allele might be related to cancer. Women who inherit a germ-line BRCA1 or BRCA2 mutation face a high lifetime cumulative risk (penetrance) of developing breast cancer (BC), in the order of 55% compared to 12% in the general population, and ovarian cancer (OC) in the order of 16-59% (1-4). Given the incomplete penetrance, it has been suggested that several factors, genetic (polymorphisms) and/or "environmental", may influence BRCA penetrance. The cancer risk is higher if genotype carriers are obese or have a high energy intake and lifelong weight gain (5-8). Obesity may affect BRCA penetrance through a number of mechanisms including insulin resistance, induction of a metabolic syndrome, chronic low-grade inflammation and insulin-like growth factor I (IGF-I) regulation. Metabolic syndrome and diabetes are also associated with hereditary BC (6, 9). A case-control analysis of 308 high genetic-risk women showed that high serum levels of IGF-I were associated with significantly greater penetrance (10). Body weight is regulated by leptin and adiponectin, two adipokines that have pathological signaling cascades in relation to the pathogenesis of various diseases, including cancer (11-20). Leptin is an adipokine produced in white adipose tissue that controls appetite and energy balance, increases with BMI (16) and is linked epidemiologically with obesity-related cancers, including sporadic BC risk (13, 21). Adiponectin, an adipose-derived protein of 244 amino acids, is an endogenous insulin sensitizer that also regulates the secretion of estrogens, TNF-α and IGF-I (11, 14). It has an inverse relationship with adiposity, so its levels are low in obese and diabetic subjects, with a stronger negative correlation with visceral adiposity (16). Adiponectin is inversely related to the risk of obesity-related cancers, including sporadic BC, even after controlling for BMI or other anthropometric markers (18).