title: Clinical significance of evaluating primary lesions in patients with gastric cancer who receive chemotherapy.
abstract: BACKGROUND
  In Western countries, the response of gastric cancer to chemotherapy is evaluated by assessing measurable metastatic lesions (MMLs) according to the response evaluation criteria in solid tumors (RECIST). In Japan, the response of primary lesions is assessed according to local Japanese criteria. We compared the response to chemotherapy as evaluated by these two sets of criteria.
  
  
  METHODS
  Patients with unresectable, advanced gastric cancer who had primary lesions and had received first-line chemotherapy were studied. Responses of MMLs were evaluated with RECIST. Responses of primary lesions were evaluated with the Japanese criteria. Median survival times (MSTs) were compared according to treatment response by each set of criteria.
  
  
  RESULTS
  Data from 341 patients were analyzed. Of the 242 patients with MMLs, 108 were MML responders and 134 were MML nonresponders. MST was significantly longer in MML responders (293 days; 95% confidence interval [CI], 244-342) than in MML nonresponders (159 days; 95% CI, 127-191; P < 0.0001). According to the Japanese criteria, there were 128 primary-lesion responders and 213 primary-lesion nonresponders. MST was significantly longer in responders (304 days; 95% CI, 266-342) than in nonresponders (168 days; 95% CI, 143-193, P < 0.0001). Of the 99 patients without MMLs, 26 were primary-lesion responders and 73, primary-lesion nonresponders; MST was significantly longer in the former (300 days; 95% CI, 266-334) than in the latter group (173 days; 95% CI, 111-235; P = 0.019).
  
  
  CONCLUSIONS
  The responses of primary lesions according to the Japanese criteria and the responses of MMLs according to the RECIST were both significantly related to the MST. Use of the RECIST alone might bias the evaluation of treatment response because response cannot be evaluated in patients without an MML.
authors.affiliation: Department of Gastroenterology, Kitasato University School of Medicine, Sagamihara, Kanagawa, Japan.
authors.forename: Kento
authors.initials: K
authors.lastname: Nakatani
authors.forename: Wasaburo
authors.initials: W
authors.lastname: Koizumi
authors.forename: Katsuhiko
authors.initials: K
authors.lastname: Higuchi
authors.forename: Chikatoshi
authors.initials: C
authors.lastname: Katada
authors.forename: Toru
authors.initials: T
authors.lastname: Sasaki
authors.forename: Norisuke
authors.initials: N
authors.lastname: Nakayama
authors.forename: Satoshi
authors.initials: S
authors.lastname: Tanabe
authors.forename: Katsunori
authors.initials: K
authors.lastname: Saigenji
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000970:Antineoplastic Agents / Q000627:therapeutic use*; D016001:Confidence Intervals; D005060:Europe; D005260:Female; D006801:Humans; D007564:Japan; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D009656:North America; D011379:Prognosis; D012189:Retrospective Studies; D013274:Stomach Neoplasms / Q000188:drug therapy* / Q000401:mortality / Q000473:pathology*; D016896:Treatment Outcome
chemical_list: D000970:Antineoplastic Agents