title: Prevalence, clinicopathological characteristics, treatment, and prognosis of intestinal metastasis of primary lung cancer: a comprehensive review.
abstract: OBJECTIVE
  Lung cancer is mostly diagnosed at the advanced stage of disease. This review focused on prevalence, clinicopathological characteristics, treatment, and prognosis of intestine metastasis of primary lung cancer.
  
  
  METHODS
  Published literature was searched using PubMed/Medline databases to extract studies on primary lung cancer metastasized to the intestine and then analyzed statistically.
  
  
  RESULTS
  A total of 57 case reports and 3 retrospective studies were obtained from PubMed database. The prevalence of small bowel metastasis of primary lung cancer ranged between 2.6 and 10.7%. Histologically, poor tumor differentiation and advanced T and N stages of primary lung cancer associated with intestinal metastasis. Clinically, primary lung cancer metastasized to the intestine led to three frequent clinical presentations, i.e., intestine perforation, obstruction, and bleeding. The time interval between diagnosis of primary tumor and manifestation of intestinal metastasis ranged between 2 week and 4 years, while the time was within one year for 36 reported cases. 70% (45 of 63 cases) of patients did have an extra-intestinal metastasis at diagnosis of intestine metastasis. The median survival rate of 79 patients with follow-up data was 2.3 month and the old age, extra-intestinal metastasis, and intestine perforation were associated with poor prognosis.
  
  
  CONCLUSIONS
  This study suggests that the primary lung cancer metastasized to the small bowel is not so rare as it is thought. Clinical management and treatment decision will be warranted and considered accordingly.
authors.affiliation: Department of Surgery, Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao-Tong University, Shanghai 200233, China.
authors.forename: Jian-Zhong
authors.initials: JZ
authors.lastname: Di
authors.affiliation: Department of Surgery, Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao-Tong University, Shanghai 200233, China. Electronic address: ppsuzhi@gmail.com.
authors.forename: Jia-Yuan
authors.initials: JY
authors.lastname: Peng
authors.affiliation: Department of Surgery, Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao-Tong University, Shanghai 200233, China.
authors.forename: Zhi-Gang
authors.initials: ZG
authors.lastname: Wang
mesh_terms: D002681:China / Q000453:epidemiology; D006801:Humans; D007414:Intestinal Neoplasms / Q000453:epidemiology / Q000401:mortality / Q000556:secondary / Q000628:therapy*; D008175:Lung Neoplasms / Q000401:mortality / Q000473:pathology / Q000628:therapy*; D011379:Prognosis; D015996:Survival Rate
keywords: Intestine metastasis; Lung cancer; Non-small cell lung cancer