Molecular profiling of pediatric and young adult colorectal cancer reveals a distinct genomic landscapes and potential therapeutic avenues.

Colorectal cancer (CRC) is a global health concern, and the incidence of early onset (EO) CRC, has an upward trend. This study delves into the genomic landscape of EO-CRC, specifically focusing on pediatric (PED) and young adult (YA) patients, comparing them with adult (AD) CRC. In this retrospective monocentric investigation, we performed targeted next-generation sequencing to compare the mutational profile of 38 EO-CRCs patients (eight PED and 30 YA) to those of a 'control group' consisting of 56 AD-CRCs. Our findings reveal distinct molecular profiles in EO-CRC, notably in the WNT and PI3K-AKT pathways. In pediatrics, we observed a significantly higher frequency of RNF43 mutations, whereas APC mutations were more prevalent in adult cases. These observations suggest age-related differences in the activation of the WNT pathway. Pathway and copy number variation analysis reveal that AD-CRC and YA-CRC have more similarities than the pediatric patients. PED shows a peculiar profile with CDK6 amplification and the enrichment of lysine degradation pathway. These findings may open doors for personalized therapies, such as PI3K-AKT pathway inhibitors or CDK6 inhibitors for pediatric patients. Additionally, the distinct molecular signatures of EO-CRC underscore the need for age-specific treatment strategies and precision medicine. This study emphasizes the importance of comprehensive molecular investigations in EO-CRCs, which can potentially improve diagnostic accuracy, prognosis, and therapeutic decisions for these patients. Collaboration between the pediatric and adult oncology community is fundamental to improve oncological outcomes for this rare and challenging pediatric tumor.

Efficacy and safety of single-agent pan-human epidermal growth factor receptor (HER) inhibitor dacomitinib in locally advanced unresectable or metastatic skin squamous cell cancer.

BACKGROUND: In recurrent or metastatic (R/M) skin squamous cell cancer (sSCC) not amenable to radiotherapy (RT) or surgery, chemotherapy (CT) has a palliative intent and limited clinical responses. The role of oral pan-HER inhibitor dacomitinib in this setting was investigated within a clinical trial. METHODS: Patients with diagnosis of R/M sSCC were treated. Dacomitinib was started at a dose of 30 mg daily (QD) for 15 d, followed by 45 mg QD. Primary end-point was response rate (RR). Tumour samples were analysed through next-generation sequencing using a custom panel targeting 36 genes associated with sSCC. RESULTS: Forty-two patients (33 men; median age 77 years) were treated. Most (86%) received previous treatments consisting in surgery (86%), RT (50%) and CT (14%). RR was 28% (2% complete response; 26% partial response), disease control rate was 86%. Median progression-free survival and overall survival were 6 and 11 months, respectively. Most patients (93%) experienced at least one adverse event (AE): diarrhoea, skin rash (71% each), fatigue (36%) and mucositis (31%); AEs grade 3-4 occurred in 36% of pts. In 16% of cases, treatment was discontinued because of drug-related toxicity. TP53, NOTCH1/2, KMT2C/D, FAT1 and HER4 were the most frequently mutated genes. BRAF, NRAS and HRAS mutations were more frequent in non-responders, and KMT2C and CASP8 mutations were restricted to this subgroup. CONCLUSIONS: In sSCC, dacomitinib showed activity similar to what was observed with anti-epidermal growth factor receptor agents, and durable clinical benefit was observed. Safety profile was comparable to previous experiences in other cancers. Molecular pt selection could improve therapeutic ratio.

Negative hyper-selection of metastatic colorectal cancer patients for anti-EGFR monoclonal antibodies: the PRESSING case-control study.

BACKGROUND: Refining the selection of metastatic colorectal cancer patients candidates for anti-epidermal growth factor receptor (EGFR) monoclonal antibodies beyond RAS and BRAF testing is a challenge of precision oncology. Several uncommon genomic mechanisms of primary resistance, leading to activation of tyrosine kinase receptors other than EGFR or downstream signalling pathways, have been suggested by preclinical and retrospective studies. PATIENTS AND METHODS: We conducted this multicentre, prospective, case-control study to demonstrate the negative predictive impact of a panel of rare genomic alterations [PRESSING (PRimary rESiStance IN RAS and BRAF wild-type metastatic colorectal cancer patients treated with anti-eGfr monoclonal antibodies) panel], including HER2/MET amplifications, ALK/ROS1/NTRK1-3/RET fusions and PIK3CA mutations. Hypothesizing a prevalence of candidate alterations of 15% and 0% in resistant and sensitive RAS and BRAF wild-type patients, respectively, with two-sided α and ß errors of 0.05 and 0.20, 47 patients per group were needed. RESULTS: Forty-seven patients per group were included. PRESSING panel alterations were significantly more frequent in resistant (24 out of 47, 51.1%) than in sensitive (1 out of 47, 2.1%) patients (P < 0.001) and in right- (12 out of 29, 41.4%) than left-sided (13 out of 65, 20.0%) tumours (P = 0.03). The predictive accuracy of PRESSING panel and sidedness was 75.3% and 70.2%, respectively. Among hyper-selected patients, right-sidedness was still associated with resistance (P = 0.002). The predictive accuracy of the combined evaluation of PRESSING panel and sidedness was 80.4%. As a secondary analysis, 8 (17.0%) resistant and 0 sensitive patients showed microsatellite instability (P < 0.001). CONCLUSION: The investigated panel of genomic alterations allows refining the selection of RAS and BRAF wild-type metastatic colorectal cancer patients candidates for anti-EGFRs, partially explaining and further corroborating the predictive ability of primary tumour sidedness.

Pazopanib in advanced germ cell tumors after chemotherapy failure: results of the open-label, single-arm, phase 2 Pazotest trial.

Background: Therapeutic options for patients with chemoresistant germ cell tumors (GCTs) are limited. Pazopanib is a selective tyrosine kinase inhibitor with distinct antiangiogenic activity. We aimed to evaluate pazopanib activity in patients with refractory GCT. Patients and methods: In the open-label, single-arm, phase 2 Pazotest study (NCT01743482), patient eligibility included failure of ≥2 platinum-based regimens, and allowed prior high-dose chemotherapy administration. Patients were given pazopanib 800 mg/day until disease progression (PD) or onset of unacceptable toxicity. Measurements of serum tumor markers (STM), computed tomography and FDG-PET were carried out at baseline, after 4 weeks of pazopanib treatment, and every 8 weeks thereafter. PD was defined as increasing levels of STM, increasing size of non-teratomatous masses, or appearance of new lesions. The study primary endpoint was progression-free survival (PFS, H0: 3-month PFS ≤ 10%, H1: ≥25%, α = 5%, ß = 20%). Results: Forty-three patients were enrolled from May 2013 to July 2016. The number of prior chemotherapy regimens was: 2 (11.6%), 3 (51.2%), >3 (37.2%). Grade 3 adverse events were observed in six patients (13.9%). Overall, 70.3% of patients had reduced levels of STM after 4 weeks. There were 2 partial responses (4.7%), 19 cases of stable disease, and 16 cases of PD (6 not evaluable by RECIST). The median follow-up duration was 29.6 months. The 3-month PFS probability was 12.8% [95% confidence interval (CI): 5.7%-28.9%]. The 24-month OS probability was 14.2% (95% CI: 6.0%-33.7%). In patients with a >50% decline in STM, the 24-month OS probability was 24.1% (95% CI: 8.3%-69.6%). The small sample size was the major limitation. Conclusions: Despite pazopanib showed potent but short-lived activity in refractory GCT, long-term survival was obtained in a proportion of treated patients. According to the kinetics of pazopanib activity, this drug may be investigated in less pre-treated patients as an optimal bridging therapy preceding and/or combined with salvage chemotherapy.

Toward the molecular dissection of peritoneal pseudomyxoma.

BACKGROUND: Outcome of pseudomyxoma peritonei (PMP) after cytoreductive surgery (CRS) and hypertermic intraperitoneal chemotherapy (HIPEC) is heterogeneous even after adjusting for clinico-pathological prognostic variables. The identification of additional prognostic or even predictive biomarkers is an unmet clinical need. PATIENTS AND METHODS: Forty patients with mucinous appendiceal tumors and PMP were clinically eligible and had evaluable tumor samples obtained after CRS and HIPEC. We carried out next-generations sequencing (NGS) of 50 gene's hotspot regions contained in the Hotspot Cancer Panel v2 using the Ion Torrent Personal Genome Machine platform (Life Technologies). RESULTS: KRAS and GNAS mutations were found in 72% and 52%, and their allelic frequency was below 10% in 55% and 43% of samples, respectively. KRAS and GNAS mutations were associated with worse progression-free survival (PFS) at univariate analysis (P = 0.006 and 0.011, respectively). At multivariate analysis, only KRAS mutations were independently associated with PFS (P = 0.012); GNAS mutations were not-being significantly associated with other poor prognostic features such as incomplete cytoreduction or KRAS mutations. Validation of results was carried out in an independent bi-institutional cohort of 25 patients and the prognostic effect of KRAS mutations was again confirmed in the multivariate model (P = 0.029). NGS approach allowed the discovery of other potentially druggable mutations such as those in PI3K, AKT, LKB1, FGFR3 and PDGFRA. CONCLUSIONS: Given the homogeneity of this series and the sensitivity of NGS in this low-cellularity tumor, we demonstrated for the first time a poor prognostic role of KRAS mutations.

Activity of temozolomide in patients with advanced chemorefractory colorectal cancer and MGMT promoter methylation.

BACKGROUND: No evidence-based treatment options are available for patients with advanced colorectal cancer (CRC) progressing after standard therapies. MGMT is involved in repair of DNA damage and MGMT promoter methylation may predict benefit from alkylating agents such as temozolomide. The aim of our study was to evaluate the activity of temozolomide in terms of response rate in patients with metastatic CRC and MGMT methylation, after failure of approved treatments. PATIENTS AND METHODS: Patients were enrolled in a monocentre, open-label, phase II study and treated with temozolomide at a dose of 150 mg/m2/day for 5 consecutive days in 4-weekly cycles. The treatment was continued for at least six cycles or until progressive disease. RESULTS: Thirty-two patients were enrolled from August 2012 to July 2013. Treatment was well tolerated with one grade 4 thrombocytopenia and no other grade≥3 toxicities. No complete response occurred. The objective response rate was 12%, reaching the pre-specified level for promising activity. Median progression-free survival and overall survival were 1.8 and 8.4 months, respectively. Patients with KRAS, BRAF and NRAS wild-type CRC showed significantly higher response when compared with those with any RAS or BRAF mutation (44% versus 0%; P=0.004). TP53 status had no influence on the primary end point. CONCLUSIONS: Temozolomide is tolerable and active in heavily pre-treated patients with advanced CRC and MGMT promoter methylation. Further studies in biomolecularly enriched populations or in a randomized setting are necessary to demonstrate the efficacy of temozolomide after failure of standard treatments.