Histologic and Genotypic Characterization of Lung Cancer in the Inuit Population of the Eastern Canadian Arctic.

Inuit are the Indigenous Arctic peoples and residents of the Canadian territory of Nunavut who have the highest global rate of lung cancer. Given lung cancer's mortality, histological and genomic characterization was undertaken to better understand the disease biology. We retrospectively studied all Inuit cases from Nunavut's Qikiqtani (Baffin) region, referred to the Ottawa Hospital Cancer Center between 2001 and 2011. Demographics were compiled from medical records and tumor samples underwent pathologic/histologic confirmation. Tumors were analyzed by next generation sequencing (NGS) with a cancer hotspot mutation panel. Of 98 patients, the median age was 66 years and 61% were male. Tobacco use was reported in 87%, and 69% had a history of lung disease (tuberculosis or other). Histological types were: non-small cell lung carcinoma (NSCLC), 81%; small cell lung carcinoma, 16%. Squamous cell carcinoma (SCC) represented 65% of NSCLC. NGS on 55 samples demonstrated mutation rates similar to public lung cancer datasets. In SCC, the STK11 F354L mutation was observed at higher frequency than previously reported. This is the first study to characterize the histologic/genomic profiles of lung cancer in this population. A high incidence of SCC, and an elevated rate of STK11 mutations distinguishes this group from the North American population.

Tumor genomic, transcriptomic, and immune profiling characterizes differential response to first-line platinum chemotherapy in high grade serous ovarian cancer.

BACKGROUND: In high grade serous ovarian cancer (HGSOC), there is a spectrum of sensitivity to first line platinum-based chemotherapy. This study molecularly characterizes HGSOC patients from two distinct groups of chemotherapy responders (good vs. poor). METHODS: Following primary debulking surgery and intravenous carboplatin/paclitaxel, women with stage III-IV HGSOC were grouped by response. Patients in the good response (GR) and poor response (PR) groups respectively had a progression-free intervals (PFI) of ≥12 and ≤6 months. Analysis of surgical specimens interrogated genomic and immunologic features using whole exome sequencing. RNA-sequencing detected gene expression outliers and inference of immune infiltrate, with validation by targeted NanoString arrays. PD-L1 expression was scored by immunohistochemistry (IHC). RESULTS: A total of 39 patient samples were analyzed (GR = 20; PR = 19). Median PFI for GR and PR patient cohorts was 32 and 3 months, respectively. GR tumors were enriched for loss-of-function BRCA2 mutations and had a significantly higher nonsynonymous mutation rate compared to PR tumors (p = 0.001). Samples from the PR cohort were characterized by mutations in MGA and RAD51B and trended towards a greater rate of amplification of PIK3CA, MECOM, and ATR in comparison to GR tumors. Gene expression analysis by NanoString correlated increased PARP4 with PR and increased PD-L1 and EMSY with GR. There was greater tumor immune cell infiltration and higher immune cell PD-L1 protein expression in the GR group. CONCLUSIONS: Our research demonstrates that tumors from HGSOC patients responding poorly to first line chemotherapy have a distinct molecular profile characterized by actionable drug targets including PARP4.

Vulvar Squamous Cell Carcinoma (VSCC) as Two Diseases: HPV Status Identifies Distinct Mutational Profiles Including Oncogenic Fibroblast Growth Factor Receptor 3.

Purpose: Patients with advanced or recurrent invasive vulvar squamous cell carcinoma (VSCC) have limited treatment options and a grave prognosis. Understanding the genomic landscape may facilitate the identification of new therapies and improve clinical outcomes.Experimental Design: A retrospective chart review and molecular analysis of patients with VSCC from 2000 to 2016 was performed at the Ottawa Hospital Research Institute. The presence of oncogenic human papillomavirus (HPV) was determined by nested PCR and amplified DNA was sequenced using the Ion AmpliSeq Cancer Hotspot v2 Panel. The patients were divided into two groups according to HPV status (HPV-positive versus HPV-negative) and clinical outcome correlated with mutation status using descriptive statistics.Results: In 43 VSCC patients, there was a high mutation rate in both HPV-positive (73%) and HPV-negative (90%) disease with the two subgroups expressing distinct genetic profiles. HPV-positive tumors were characterized by oncogenic mutations in PIK3CA (27%), FGFR3 (14%), and PTEN (9%), whereas HPV-negative tumors were found to have mutations in TP53 (57%), HRAS (24%), PI3KCA (19%), and CDKN2A (14%). Mutation S249C in FGFR3 occurred in 14% of HPV-positive tumors. While there were notable differences in the occurrence of TP53, HRAS, PTEN, and FGFR3 mutations according to HPV status, only the rate of TP53 mutations was statistically significant (P = 0.0004). No significant difference in prognosis was found between patients with HPV-positive and HPV-negative VSCC.Conclusions: HPV-positive VSCC is characterized by oncogenic FGFR3 mutations that helps classify this subtype as a separate disease. Inhibitors of FGFR3 merit consideration as a therapeutic strategy in this neglected cancer in women. Clin Cancer Res; 23(15); 4501-10. ©2017 AACR.