J. Mol. Pathol., Volume 2, Issue 1 (March 2021) – 5 articles

Activation of the PI3K–AKT–mTOR pathway occurs in several human cancers, including hormone receptor (HR)-positive breast cancer (BC) where is associated with resistance to endocrine therapy and disease progression. In BC, the most common PI3K–AKT–mTOR pathway alteration is represented by PIK3CA oncogenic mutations. These mutations can occur throughout several domains of the p110α catalytic subunit, but the majority are found in the helical and kinase domains (exon 9 and 20) that represent the “hotspots”. Considering the central role of the PI3K–AKT–mTOR pathway in HR-positive BC, several inhibitors (both pan-PI3K and isoform-specific) have been developed and tested in clinical trials. Recently, the PI3Kα-selective inhibitor alpelisib was the first PI3K inhibitor approved for clinical use in HR-positive metastatic BC based on the results of the phase III SOLAR-1 trial. Several methods to assess PIK3CA mutational status in tumor samples have been developed and validated, including real-time polymerase chain reaction (PCR), digital droplet PCR (ddPCR), BEAMing assays, Sanger sequencing, and next-generation sequencing (NGS) panels. Several new challenges will be expected once alpelisib is widely available in a clinical setting, including the harmonization of testing procedures for the detection of PI3K–AKT–mTOR pathway alterations. Herein, we provide an overview on PI3K–AKT–mTOR pathway alterations in HR-positive BC, discuss their role in determining prognosis and resistance to endocrine therapy and highlight practical considerations about diagnostic methods for the detection of PI3K–AKT–mTOR pathway activation status. Full article

(1) Background: Human papillomaviruses (HPVs) are known to be related to the development of about 5% of all human cancers. The clinical relevance of HPV infection has been deeply investigated in carcinomas of the oropharyngeal area, uterine cervix, and anogenital area. To date, several different methods have been used for detecting HPV infection. The aim of the present study was to compare three different methods for the diagnosis of the presence of the HPV genome. (2) Methods: A total of 50 samples were analyzed. Twenty-five of them were tested using both next generation sequencing (NGS) and VisionArray^® technology, the other 25 were tested using Hybrid Capture (HC) II assay and VisionArray^® technology. (3) Results: A substantial agreement was obtained using NGS and VisionArray^® (κ = 0.802), as well as between HC II and VisionArray^® (κ = 0.606). In both analyses, the concordance increased if only high risk HPVs I(HR-HPVs) were considered as “positive”. (4) Conclusions: Our data highlighted the importance of technical choice in HPV characterization, which should be guided by the clinical aims, costs, starting material, and turnaround time for results. Full article

With a growing number of clinically relevant biomarkers needed to guide the management of patients with non-small cell lung cancer (NSCLC), pathologists are keenly aware of the need to collect adequate tissue not only for a diagnosis, but also for ancillary studies to provide predictive and prognostic information. Small specimens collected by minimally invasive techniques such as fine needle aspiration and core needle biopsy often fall short in meeting adequacy requirements for lung cancer molecular biomarkers. The College of American Pathologists (CAP) recently published an evidence-based clinical practice guideline, “Collection and Handling of Thoracic Small Biopsy and Cytology Specimens for Ancillary Studies”, to help direct clinicians and pathology laboratory personnel to optimally collect and handle thoracic small specimens for ancillary testing. This review summarizes the published guideline statements and provides a brief overview of the recommendations and how they impact the practice of pathology. Full article

Mucinous pancreatic cysts are precursor lesions of ductal adenocarcinoma. Discoveries of the molecular alterations detectable in pancreatic cyst fluid (PCF) that help to define a mucinous cyst and its risk for malignancy have led to more routine molecular testing in the preoperative evaluation of these cysts. The differential diagnosis of pancreatic cysts is broad and ranges from non-neoplastic to premalignant to malignant cysts. Not all pancreatic cysts—including mucinous cysts—require surgical intervention, and it is the preoperative evaluation with imaging and PCF analysis that determines patient management. PCF analysis includes biochemical and molecular analysis, both of which are ancillary studies that add significant value to the final cytological diagnosis. While testing PCF for carcinoembryonic antigen (CEA) is a very specific test for a mucinous etiology, many mucinous cysts do not have an elevated CEA. In these cases, detection of a KRAS and/or GNAS mutation is highly specific for a mucinous etiology, with GNAS mutations supporting an intraductal papillary mucinous neoplasm. Late mutations in the progression to malignancy such as those found in TP53, p16/CDKN2A, and/or SMAD4 support a high-risk lesion. This review highlights PCF triage and analysis of pancreatic cysts for optimal cytological diagnosis. Full article

Patients with non-small-cell lung cancer (NSCLC), harboring Epidermal Growth Factor Receptor (EGFR) mutations, are more susceptible to brain metastases (BM). Comparisons of the efficacy of different-generation EGFR-tyrosine kinase inhibitors (TKI) on BMs from NSCLC are currently limited. We identified studies comparing different EGFR-TKIs for NSCLC through Pubmed literature search and selected those with neurological outcome data. By two retrospective analyses, Erlotinib showed longer neurological time-to-progression (30 months vs. 15.8 months, P = 0.024) and reduced the risk of central nervous system (CNS) progression (Hazard Ratio (HR) 0.25; 95% CI, 0.08–0.81; P = 0.021) compared to Gefitinib. In a phase 2b randomized trial, 16% of patients with BMs had a similar Progression Free Survival (PFS) (HR 0.76, 95% CI 0.41–1.44) or Overall Survival (OS) (HR 1.16, 95% CI 0.61–2.21) with Afatinib versus Gefitinib; a lower risk of developing subsequent BMs with Afatinib than Gefitinib (HR 0.49; 95% CI 0.34–0.71; P < 0.001) was reported by a retrospective study. A randomized phase 3 trial proved that patients with BMs treated with Osimertinib had longer PFS (HR 0.47, 95% CI 0.30–0.74) and OS (HR 0.79, 95% CI 0.61–1.01) than with Gefitinib, and lower incidence of CNS progression (6% vs. 15%, respectively). Although there is limited evidence, differences in CNS activity may exist between EGFR-TKIs. Full article