Metastasis from small-cell lung cancer to the colon is very rare. A 74-year-old man without respiratory or abdominal symptoms underwent a follow-up lower gastrointestinal endoscopy after a polypectomy. He was diagnosed with a 5 mm IIa non-hyperplastic polyp in the cecum and underwent a cold snare polypectomy. The histopathological findings confirmed the diagnosis of small cell carcinoma. The tumor was positive in the deep margins of the submucosal layer. Subsequent systemic examination revealed a mass in the lower lobe of the left lung. Thus, the tumor in the cecum was determined to be a colorectal metastasis from primary small-cell carcinoma of the lung. Metastasis to the colon was diagnosed as small-cell lung cancer based on local positivity for thyroid transcription factor-1 and morphologic and immunochemical features. To our best knowledge, this is the first report of colon metastasis from small cell carcinoma identified by endoscopic treatment.

Squamous cell lung carcinoma (LUSC) originates from squamous cells and has a high rate of metastasis and recurrence. The lack of effective genetic targets and specific therapies has resulted in a poor prognosis for patients with LUSC. Gastrointestinal metastasis of LUSC is a rare occurrence in clinical practice. Patients with gastrointestinal metastasis usually have worse overall survival and the process of diagnosis is more complicated than those with metastasis elsewhere. What's more, there are no helpful guidelines for treating patients with a clinically confirmed diagnosis of gastrointestinal metastasis, which means the treatment method is limited. Here, we review the clinical features, diagnosis, and treatment of LUSC patients with gastrointestinal metastasis and report a rare case of LUSC accompanied by gastrointestinal metastasis. The patient was admitted to the hospital with coughing and hemoptysis. A tumor was found in his lung, and lesions were initially controlled with standard treatment. The patient's tumor re-occurred again shortly for which treatment was lacking. Without effective treatment methods, the disease was difficult to control. Our learnings from the case demonstrate that LUSC metastasizes to secondary lymphoid organs of the gastrointestinal tract, usually with a poor prognosis.

Transformation to small cell lung cancer (SCLC) is one of the mechanisms of resistance to epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs). However, no standard treatment is available after the transformation. In addition, gastric metastasis of primary lung cancer is rarely observed; thus, little is known about its metastatic characteristics.

A 58-year-old male patient was treated with gefitinib (0.25 g /day) as the 1st line treatment due of recurrence after surgical resection for EGFR exon 19 mutation pulmonary adenocarcinoma. However, he experienced recurrence with positive T790 M, and osimertinib (80 mg/day) was administered as the 2nd line therapy.

One year and 6 months after osimertinib initiation, he complained of stomachache, and a diagnostic gastroscopy biopsy confirmed small cell lung cancer in the gastric body, indicating osimertinib-induced phenotypic transformation.

The patient was treated with etoposide and platinum chemotherapy and maintenance therapy with osimertinib. Finally, the patient achieved a partial response after 4 cycles.

Timely second biopsies should be considered in the diagnosis of phenotypic transformation. After transformation, chemotherapeutic treatment with etoposide and platinum and maintenance therapy with osimertinib inhibited the progression of the disease.

Nearly 50% of primary lung carcinoma patients present with distant metastasis at their first visit. However, gastrointestinal tract (GIT) metastasis is an infrequent impediment. Herein, we report a case of progressive dysphagia and epigastralgia as an initial manifestation of recurrence as gastric metastasis of primary lung squamous cell carcinoma (SCC) after curative surgery. A 64-year-old man was diagnosed with primary lung SCC of the right lower lobe, and underwent thoracoscopic lower lobectomy. One year after lobectomy, computed tomography (CT) scan showed a gastric fundal mass located in the gastric cardia which measured 5 cm. Endoscopic biopsies and histopathology subsequently confirmed that tumor was SCC. The patient then underwent proximal gastrectomy with resection of the diaphragmatic crus. Following surgery, histopathological examination revealed gastric metastasis from primary lung SCC. KEY POINTS: Gastric metastasis of primary lung carcinoma is one of the rarest phenomena. Gastrointestinal symptoms should raise suspicion of the presence of advanced metastatic disease with poor prognosis.

The purpose of this current study is to elucidate whether altered microRNA-365 (miR-365) has an association with the initiation and development of non-small-cell lung cancer (NSCLC) by targeting TRIM25 expression. The expression of miR-365 and TRIM25 in NSCLC tissues, adjacent normal tissues, and NSCLC cell lines were detected. The relationship between miR-365 expression and TRIM25 with the clinicopathological characteristics of NSCLC was analyzed. The putative binding site between miR-365 and TRIM25 was determined by luciferase activity assay. miR-365 inhibitors and miR-365 mimics were transfected to human NSCLC A549 cells, and the cell viability was detected by cell counting kit-8 assay; flow cytometry was carried out to determine cell cycle and apoptosis rate. Poorly expressed miR-365 and overexpressed TRIM25 was found in NSCLC tissues. TRIM25 was determined as a target gene of miR-365. The miR-365 and TRIM25 expression were related to the clinicopathological features of NSCLC, such as pathological classification, differentiation degree, TNM stage as well as lymph node metastasis. miR-365 suppressed the expression of TRIM25 and elevated the expression of the proapoptotic protein in NSCLC cells. Our study demonstrates that altered expression of miR-365 has a close association with the occurrence and development of NSCLC by inhibiting TRIM25 expression.

The GI tract is rarely affected by secondary tumors. Patients often present at an advanced stage of the disease, and prognosis is dismal. This study aimed to analyze the clinical, endoscopic, and pathologic features of secondary tumors that had been diagnosed endoscopically.

We conducted a retrospective database analysis of 217 patients with secondary tumors of the GI tract. Endoscopic findings and histologic diagnoses were systematically re-evaluated.

Malignant melanoma (n = 33, 15%), breast cancer (n = 32, 15%), and pancreatic cancer (n = 27, 12%) were the most common corresponding primaries. About one-third of secondary tumors were detected in the stomach (n = 76, 35%), followed by small intestine (n = 54, 25%) and rectum (n = 53, 24%). The median time between the diagnoses of primary and secondary tumors was 19 months (mean, 31; range, 0-251), and this time was particularly long for renal cell carcinoma and breast cancer (median, 38 and 45 months, respectively). Direct invasion from extra-GI malignancies was more common (56%) than vascular cancer spread (44%) and depended on both sites of tumor involvement and corresponding primary. The lesions presented with various endoscopic patterns. In patients for whom a definitive diagnosis of cancer was known before the examination (n = 168), a secondary tumor was included in the differential diagnosis in only 48% of lesions. It is of note that the remaining cases were diagnosed endoscopically as primary tumors and rarely also as nonneoplastic change.

Secondary tumors may affect all parts of the GI tract. Malignant melanoma and breast and pancreatic cancer represent the most common primaries. Diagnosis based on examination of biopsy specimens is crucial to avoid misclassification.

Gastrointestinal multiple metastases of lung cancer are extremely rare. The majority of gastrointestinal metastasis cases are diagnosed at a late stage and the prognosis is extremely poor. This report describes the clinical characteristics and outcomes of a patient with gastrointestinal multiple metastases from squamous-cell lung cancer, with special emphasis on the diagnosis and treatment of metastatic lung cancer.

A 61-year-old man who presented with progressive abdominal distention was admitted to our hospital. Radiological examinations showed changes of post-primary pulmonary tuberculosis and mechanical obstruction of the small bowl. Histopathological findings of gastroscopic examination and biopsy specimens showed a diagnosis of squamous-cell carcinoma in the body of the stomach.

Postoperative histopathology confirmed a gastrointestinal multiple squamous-cell carcinoma in stomach and small bowl. Finally, squamous-cell lung cancer was confirmed by lung biopsy.

During his hospitalization urgent surgery was performed because of acute abdomen. The patient underwent a laparotomy with curative gastrectomy for gastric cancer and small bowel partial resection. The patient was recommended with combination chemotherapy of carboplatin and paclitaxel for 3 cycles.

Six months later after operation, the patient succumbed to respiratory failure.

We searched the related literature of gastrointestinal metastases from lung cancer and the clinical presentation, site of metastasis, diagnosis, treatment, and survival time in these cases were reviewed. The present study may increase the awareness of early diagnosis and appropriate treatment of metastatic lung cancer of gastrointestinal tract.

Lung cancer is one of the most common causes of cancer-related deaths worldwide. Although great efforts and progressions have been made in the study of the lung cancer in the recent decades, the mechanism of lung cancer formation remains elusive. To establish effective therapeutic methods, new targets implied in lung cancer processes have to be identified. Tripartite motif-containing 25 has been associated with ovarian and breast cancer and is thought to positively promote cell growth by targeting the cell cycle. However, whether tripartite motif-containing 25 has a function in lung cancer development remains unknown. In this study, we found that tripartite motif-containing 25 was overexpressed in human lung cancer tissues. Expression of tripartite motif-containing 25 in lung cancer cells is important for cell proliferation and migration. Knockdown of tripartite motif-containing 25 markedly reduced proliferation of lung cancer cells both in vitro and in vivo and reduced migration of lung cancer cells in vitro Meanwhile, tripartite motif-containing 25 silencing also increased the sensitivity of doxorubicin and significantly increased death and apoptosis of lung cancer cells by doxorubicin were achieved with knockdown of tripartite motif-containing 25. We also observed that tripartite motif-containing 25 formed a complex with p53 and mouse double minute 2 homolog (MDM2) in both human lung cancer tissues and in lung cancer cells and tripartite motif-containing 25 silencing increased the expression of p53. These results provide evidence that tripartite motif-containing 25 contributes to the pathogenesis of lung cancer probably by promoting proliferation and migration of lung cancer cells. Therefore, targeting tripartite motif-containing 25 may provide a potential therapeutic intervention for lung cancer.