Multiparametric Phenotyping of Circulating Tumor Cells for Analysis of Therapeutic Targets, Oncogenic Signaling Pathways and DNA Repair Markers.

Detection of circulating tumor cells (CTCs) has been established as an independent prognostic marker in solid cancer. Multiparametric phenotyping of CTCs could expand the area of application for this liquid biomarker. We evaluated the Amnis® brand ImageStream®X MkII (ISX) (Luminex, Austin, TX, USA) imaging flow cytometer for its suitability for protein expression analysis and monitoring of treatment effects in CTCs. This was carried out using blood samples from patients with head and neck squamous cell carcinoma (n = 16) and breast cancer (n = 8). A protocol for negative enrichment and staining of CTCs was established, allowing quantitative analysis of the therapeutic targets PD-L1 and phosphorylated EGFR (phospho-EGFR), and the treatment response marker γH2AX as an indicator of radiation-induced DNA damage. Spiking experiments revealed a sensitivity of 73% and a specificity of 100% at a cut-off value of ≥3 CTCs, and thus confirmed the suitability of the ISX-based protocol to detect phospho-EGFR and γH2AX foci in CTCs. Analysis of PD-L1/-L2 in both spiked and patient blood samples further showed that assessment of heterogeneity in protein expression within the CTC population was possible. Further validation of the diagnostic potential of this ISX protocol for multiparametric CTC analysis in larger clinical cohorts is warranted.

Prognostic significance of Ki-67 levels and hormone receptor expression in low-grade serous ovarian carcinoma: an investigation of the Tumor Bank Ovarian Cancer Network.

Low-grade serous ovarian carcinoma (LGSOC) has recently come up as a distinct rare entity of epithelial ovarian cancer. Predictive and prognostic markers are not well studied yet. Because Ki-67 and hormone receptors (HR) have been established as relevant cancer biomarkers in several malignant tumors, we evaluated Ki-67 and HR expression rates by immunohistochemistry in 68 patients with LGSOC. We used a standardized cutoff finder algorithm to analyze prognostic significance for overall survival (OS) and progression-free survival (PFS). Cox regression showed a significant continuous decrease in OS for higher proliferation rates with an HR  of 1.07% (95% confidence interval, 1.01%-3.67%; P = .048) but not in PFS (P = .86). Cutoff finder analysis revealed the best possible cutoff for OS at 6.28% (P = .04) and for PFS at 1.85% proliferative activity (P = .04). Estrogen receptors (ERs) were expressed in most LGSOC patients (n = 61; 89.7%), progesterone receptor (PR) in about half of patients (n = 33; 48.5%). For both ER/PR, a statistically significant cutoff for PFS could be determined, which was at 75% of positive tumor cells for ER (P = .02) and at 15% of positive tumor cells for PR (P = .03). For OS, HR expression showed a tendency toward better OS for HR-positive tumors but did not turn out statistically significant. Our results show that Ki-67 is a valuable prognostic marker in the subgroup of LGSOC. We could also show that most LGSOCs express HRs but that this expression is associated with a better PFS, a finding valuable in times of antihormonal therapy in LGSOC.

Two patients with rare mixed adenoneuroendocrine carcinomas of the rectum.

Mixed adenoneuroendocrine carcinomas of the gastrointestinal tract are until today poorly understood and thus very challenging for interdisciplinary therapy. We herewith report the first case series of patients with a primary mixed adenoneuroendocrine carcinoma of the rectum. Both cases were initially diagnosed as adenocarcinoma and only secondarily with mixed adenoneuroendocrine carcinoma and had a poor outcome due to a rapid tumor progression and resistance to chemotherapy. A 65-year-old female presented with local tumor recurrence and hepatopulmonary metastasis 1 year after primary surgery for adenocarcinoma of the rectum and consecutive radiochemotherapy regimen. Fluorouracil (5-FU) was followed by bevacizumab- and capecitabine-based chemotherapy but had to be discontinued due to side effects and progressive disease. Progressive local pain syndrome accompanied by recurrent bleeding episodes led to a local tumor-debulking operation. Afterward, mixed adenoneuroendocrine carcinoma as the underlying diagnosis in the final histopathological examination was detected. The patient died 3 months after the operation in the context of a fulminant tumor progress. A 63-year-old male patient underwent neoadjuvant radiochemotherapy and laparoscopic rectum resection. After 5 months, postoperative oxaliplatin/capecitabine-based adjuvant chemotherapy was switched to carboplatin/etopsid due to a progressive polyneuropathy and biopsy-proven pulmonary metastasis. The patient then had to be switched to local radiation of cerebral metastases and Topotecan due to cerebral bleeding episodes but died 18 months after the initial diagnosis. In conclusion of our case series, mixed adenoneuroendocrine carcinomas of the rectum should be considered as a rare but aggressive tumor entity. An early and detailed histopathological diagnosis is required in order to establish an individual interdisciplinary treatment concept.