The patient was also prescribed erlotinib (150 mg, once per day)

The patient was also prescribed erlotinib (150 mg, once per day). identical genetic profile. The MUC16 bone lesion was identified to be a metastasis from the lung cancer. The patient was prescribed an epithelial growth factor receptor inhibitor, which resulted in a partial response in the lung mass and alleviation of the patient’s bone pain. Through this case study, we advocate the importance of using genetic testing in addition to pathological assessment. Keywords: metastasis, genetic profiling, epidermal growth factor receptor == Introduction == Cancer metastasis remains responsible for the vast majority of cases of cancer-related morbidity and mortality. Metastasis, by its definition, is the spread of cancer from the primary site to the distant tissues. The prerequisite PRT 4165 for the establishment of a diagnosis of metastasis is a consistent pathology between the primary site and the metastasis (1). However , to fully endow metastatic potential, cancer cells must accumulate a spectrum of alterations. The pathological consistency may be compromised during this accumulation. The genomic landscape has been revealed for the most common types of cancer, including lung cancer (2, 3). Lung cancer ranks first in both morbidity and mortality worldwide. Its annual incidence in China is estimated to be ~500 per million people (4). With the progress of genomic technology, lung cancer is considered as a disease of the genome. The gene mutations that confer a selective growth advantage to the tumor cell are called driver mutations (5). The most prominent driver gene in lung cancer is the epidermal growth factor receptor (EGFR) gene (6). Patients haboring EGFR mutation respond markedly to EGFR tyrosine kinase inhibitors (TKI) such as erlotinib (6). The capability of genetic testing expands our armamentarium to recognize occult cancer metastasis. The present study describes a notable case of lung cancer in which bone metastasis was revealed by genetic profiling, but was not based on pathological analysis. == Case report == A 44-year-old, non-smoking, male was admitted to West China Hospital (Chengdu, Sichuan, China) on July 16, 2014 with pain in the neck and right hip, and weight loss of 11 pounds over 3 weeks. The physical examination was normal. The patient underwent whole-body positron emission tomography-computed tomography, and PRT 4165 a mass in the upper lobe of the left lung and multiple areas of high metabolism in the bone (ilium and first cervical vertebra) were revealed. Magnetic resonance imaging of the neck showed destruction of the Atlas vertebra. The patient then underwent laminoplasty. Biopsies were performed in the right ilium and left lung, and the tissue specimens were fixed in 10% formaldehyde, embedded in paraffin, and cut into sections (5-m). For immunohistochemical analysis, the sections were incubated for 1 h at 37C with primary antibodies against cytokeratin (CK) 5/6 (1: 100; MAB-0276; Fuzhou Maixin Biotech Co., Ltd., Fuzhou, China), CK7 (1: 200; ZM-0071; OriGene Technologies, Inc., Beijing, China), P63 (1: 200; CM163C; Biocare Medical, LLC, Concord, CA, USA), NapsinA (1: 200; RAB-0639; Fuzhou Maixin Biotech Co., Ltd. ) and thyroid transcription factor (1: 200; 8G7G3/1; Abcam, Cambridge, MA, USA). Hematoxylin was used for counterstaining. The pathological examination revealed different histological types with different immunohistochemical phenotypes (Fig. 1). However , exactly the same genetic profile between these two lesions confirmed the same entity (Table I). A diagnosis of adenocarcinoma in the left lung with bone metastasis was established (cT3N3M1b, stage IV) (7). == Figure 1 . == Results of immunohistochemical analysis. Pathological examination revealed a completely different morphological and immunohistological pattern between the lung and bone lesions. While the bone lesion (lower panel) was diagnosed as squamous carcinoma, as shown by HE staining and immunohostochemical analysis, the lung lesion (upper panel) was a typical adenocarcinoma (magnification, 400). HE, hematoxylin and eosin; CK, cytokeratin; TTF, thyroid transcription factor. == Table I. == Results of genetic testing from the lung and ilium were identical. EGFR, epidermal growth factor receptor; ALK, anaplastic lymphoma receptor tyrosine kinase; ROS-1, ROS proto-oncogene 1, receptor tyrosine kinase. Zoledronic acid PRT 4165 (4 mg) was administered each month to prevent severe bone-related events. The patient was also prescribed erlotinib (150 mg, once per day). PRT 4165 The medication was well-tolerated, with the exception of a persistent acneform rash on the face (Fig. 2). This TKI treatment achieved a partial response in the primary lung lesion (Fig. 3) and relief of the pain in the right ilium. However , progression of the PRT 4165 disease occurred after 6 months of erlotinib.