Faculty Bibliography

Mixed carcinomas in the esophagus are highly uncommon neoplasms that represent a diagnostic challenge on small tissue biopsies. We present a case of a primary mixed sarcomatoid-small cell carcinoma of the esophagus that was diagnosed after repeat sampling of the lesion. The components were morphologically distinct and could be further classified by immunohistochemistry. Next-generation sequencing identified mutations in PIK3CA and CDKN2A. The small cell component morphology was also identified in brain metastasis.

BACKGROUND: Human papillomavirus (HPV) positive head and neck squamous cell carcinoma (HNSCC) accounts for 25% of HNSCCs and frequently presents with neck lymph node metastases. We investigated utilizing cytology needle rinse material for HPV DNA testing by Hybrid Capture 2 molecular testing (HC2) as an alternative to p16 immunohistochemistry. METHODS: Twenty-two cases of HNSCC presenting with neck lymph node metastasis were prospectively identified by assessment of Diff Quik stained cytology smears. An aliquot of the needle rinse material from the lymph node was analyzed for HPV status using standard HC2 protocol. P16 status was determined with immunohistochemistry on the cell block and/or surgically obtained tumor. RESULTS: The mean age of patients with p16 negative HNSCC was 7 years older than p16 positive disease (Table ). Primary tumor subsites were as follows: 17 oropharynx, 1 hypophayrnx, 3 larynx, and 1 oral cavity (Table ). All ten p16 negative patients had a history of smoking compared with 33% of p16 positive. Only 3 (25%) of p16 positive tumors demonstrated keratinization, whereas 90% of the p16 negative tumors keratinized (Fig. 1). Twelve of 22 HNSCC cases (55%) were p16 positive, of which 7 (58%) tested positive for HPV by HC2. Ten cases (45%) were negative for p16, all of which were negative for HPV by HC2 (Table ). CONCLUSION: Molecular testing for HPV using HC2 on needle rinse material of FNA of HNSCC is a useful method of determining HPV status in HNSCC.

Metastasis is a complex, multistep process of cancer progression that has few treatment options. A critical event is the invasion of cancer cells into blood vessels (intravasation), through which cancer cells disseminate to distant organs. Breast cancer cells with increased abundance of Mena [an epidermal growth factor (EGF)-responsive cell migration protein] are present with macrophages at sites of intravasation, called TMEM sites (for tumor microenvironment of metastasis), in patient tumor samples. Furthermore, the density of these intravasation sites correlates with metastatic risk in patients. We found that intravasation of breast cancer cells may be prevented by blocking the signaling between cancer cells and macrophages. We obtained invasive breast ductal carcinoma cells of various subtypes by fine-needle aspiration (FNA) biopsies from patients and found that, in an in vitro transendothelial migration assay, cells that migrated through a layer of human endothelial cells were enriched for the transcript encoding Mena(INV), an invasive isoform of Mena. This enhanced transendothelial migration required macrophages and occurred with all of the breast cancer subtypes. Using mouse macrophages and the human cancer cells from the FNAs, we identified paracrine and autocrine activation of colony-stimulating factor-1 receptor (CSF-1R). The paracrine or autocrine nature of the signal depended on the breast cancer cell subtype. Knocking down Mena(INV) or adding an antibody that blocks CSF-1R function prevented transendothelial migration. Our findings indicate that Mena(INV) and TMEM frequency are correlated prognostic markers and CSF-1 and Mena(INV) may be therapeutic targets to prevent metastasis of multiple breast cancer subtypes.

Septins are a large family of GTP-binding proteins abnormally expressed in many solid tumors. Septin 9 (SEPT9) in particular has been found overexpressed in diverse human tumors including breast, head and neck, ovarian, endometrial, kidney, and pancreatic cancer. Although we previously reported SEPT9 amplification in breast cancer, we now show specifically that high-grade breast carcinomas, the subtype with worst clinical outcome, exhibit a significant increase in SEPT9 copy number when compared with other tumor grades. We also present, for the first time, a sensitive and quantitative measure of seven (SEPT9_v1 through SEPT9_v7) isoform variant mRNA levels in mammary epithelial cells. SEPT9_v1, SEPT9_v3, SEPT9_v6, and SEPT9_v7 isoforms were expressed at the highest levels followed by SEPT9_v2 and SEPT9_v5, whereas SEPT9_v4 was almost undetectable. Although most of the isoforms were upregulated in primary tumor tissues relative to the patient-matched peritumoral tissues, SEPT9_v4 remained the lowest expressing isoform. This comprehensive analysis of SEPT9 provides substantial evidence for increased SEPT9 expression as a consequence of genomic amplification and is the first study to profile SEPT9_v1 through SEPT9_v7 isoform-specific mRNA expression in tumor and nontumor tissues from patients with breast cancer.