Assessment of common somatic mutations of EGFR, KRAS, BRAF, NRAS in pulmonary non-small cell carcinoma using iPLEX® HS, a new highly sensitive assay for the MassARRAY® System.

Increased early detection and personalized therapy for lung cancer have coincided with greater use of minimally invasive sampling techniques such as endobronchial ultrasound-guided biopsy (EBUS), endoscopic ultrasound-guided biopsy (EUS), and navigational biopsy, as well as thin needle core biopsies. As many lung cancer patients have late stage disease and other comorbidities that make open surgical procedures hazardous, the least invasive biopsy technique with the highest potential specimen yield is now the preferred first diagnostic study. However, use of these less invasive procedures generates significant analytical challenges for the laboratory, such as a requirement for robust detection of low level somatic mutations, particularly when the starting sample is very small or demonstrates few intact tumor cells. In this study, we assessed 179 clinical cases of non-small cell lung carcinoma (NSCLC) that had been previously tested for EGFR, KRAS, NRAS, and BRAF mutations using a novel multiplexed analytic approach that reduces wild-type signal and allows for detection of low mutation load approaching 1%, iPLEX® HS panel for the MassARRAY® System (Agena Bioscience, San Diego, CA). This highly sensitive system identified approximately 10% more KRAS, NRAS, EGFR and BRAF mutations than were detected by the original test platform, which had a sensitivity range of 5-10% variant allele frequency (VAF).

Distribution of human papillomavirus genotypes in invasive squamous carcinoma of the vulva.

Many studies have established a critical role for human papillomavirus (HPV) in the development of anogenital squamous neoplasia. In this report, we show the distribution of 37 high- and low-risk HPV types in 116 cases of invasive squamous vulvar carcinoma. Sections from paraffin-embedded tissue blocks were dissected as necessary to select areas of invasive carcinoma. Clinical and pathologic variables were analyzed using t-tests, univariate odds ratios and logistic regression analysis. Seventy percent of cases were HPV-positive, with an average patient age of 65 years (n=81). HPV-negative cases (n=35) had a higher average age (70 years), but these populations were not statistically different (t=1.65, P=0.10). HPV16 was most common (n=65). Other HPV types were less frequent (HPV33, n=12; HPV45, n=4; HPV52 and 6, each n=3; HPV18, 53 and 62, each n=2). Additional HPV types were identified only once. Multiple infections typically included HPV16 (12/14 cases). Tumors showing low-risk HPV (11 cases) and low-risk HPV only (three cases) were uncommon. Regional node metastasis was documented in 29 of 116 tumors, and 8/9 HPV-positive nodes contained HPV types identical to the primary tumor. Of tumor types, warty carcinoma was most strongly associated with high-risk HPV (odds ratio 4.34, 95% confidence interval 1.32-18.45), particularly high-risk HPVs other than type 16 (odds ratio 9.04, 95% confidence interval 1.60-54.00). Tumors associated with any HPV type (odds ratio 0.40, 95% confidence interval 0.14-1.17), any high-risk type (odds ratio 0.36, 95% confidence interval 0.12-1.08), or type 16 alone (odds ratio 0.34, 95% confidence interval 0.11-1.12) were less likely to metastasize than HPV-negative tumors. Correcting for possible confounding variables, such as patient age and tumor histology, linear logistic regression analysis confirmed this association (high-risk HPV odds ratio 0.28, 95% confidence interval 0.09-0.89).