title: A second malignancy is the major cause of death among thoracic squamous cell esophageal cancer patients negative for lymph node involvement.
abstract: BACKGROUND
  The aim of the present study was to determine the major causes of death among esophageal cancer patients whose lymph nodes did not show metastasis at the time they received esophagectomy, and to consider strategies for improving survival rates among these patients.
  
  
  METHODS
  Between 1989 and 1999, 93 of our patients who underwent curative esophagectomy with extended lymph node dissection for thoracic squamous cell esophageal cancer showed no lymph node metastasis. We followed up these node-negative patients for as long as 10 years and determined the major causes of death.
  
  
  RESULTS
  Sixty-three patients were still alive after esophagectomy, although 30 had died. Six patients died within 3 years after esophagectomy as a direct result of recurrence of their esophageal cancer; 13 died as a result of a second (extraesophageal) malignancy. Within the first 3 years, the major causes of death were recurrence (35%) and the second malignancy (35%); thereafter, the major cause was only the second malignancy (54%). There was no difference in the survival rates among patients with earlier, synchronous, or subsequent malignancies. Univariate and multivariate analyses of the 10-year survival showed the independent prognostic factors to be recurrence of esophageal cancer and development of a second malignancy, which respectively increased the risk of death 6.4 and 2.7 times.
  
  
  CONCLUSIONS
  The major cause of reduced survival among thoracic squamous esophageal cancer patients, whose lymph nodes did not show metastasis, was a second malignancy. New strategies aimed at preventing or treating synchronous and subsequent malignancies could prolong the survival of these patients.
authors.affiliation: Department of Surgery, Akita University School of Medicine, Akita City, Japan.
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Sato
authors.forename: Satoru
authors.initials: S
authors.lastname: Motoyama
authors.forename: Kiyotomi
authors.initials: K
authors.lastname: Maruyama
authors.forename: Manabu
authors.initials: M
authors.lastname: Okuyama
authors.forename: Junichi
authors.initials: J
authors.lastname: Ogawa
mesh_terms: D000359:Aftercare; D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D002294:Carcinoma, Squamous Cell / Q000401:mortality* / Q000473:pathology / Q000628:therapy; D002423:Cause of Death; D004938:Esophageal Neoplasms / Q000401:mortality* / Q000473:pathology / Q000628:therapy; D016629:Esophagectomy; D005260:Female; D005500:Follow-Up Studies; D006301:Health Services Needs and Demand; D006785:Hospitals, University; D006801:Humans; D007564:Japan / Q000453:epidemiology; D008197:Lymph Node Excision; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D009017:Morbidity; D009364:Neoplasm Recurrence, Local / Q000401:mortality* / Q000473:pathology / Q000628:therapy; D009367:Neoplasm Staging; D016609:Neoplasms, Second Primary / Q000401:mortality* / Q000473:pathology / Q000628:therapy; D011379:Prognosis; D016016:Proportional Hazards Models; D012307:Risk Factors; D016019:Survival Analysis