Effect of timing of metastasis/disease recurrence and histologic differentiation on survival of patients with advanced gastric cancer

Abstract

Background: Patients with advanced gastric cancer have a median survival (MS) of <9 months. It is unclear whether the MS of patients who have advanced cancer at the time of diagnosis (synchronous, Group A) is different from that for patients who develop advanced cancer after curative surgery (metachronous, Group B). It was hypothesized that survival would be similar.

Methods: The medical records of all patients treated at the University of Texas M. D. Anderson Cancer Center who were in either Group A or Group B were reviewed. Survival of patients was assessed by the Kaplan-Meier method. A Cox proportional hazards model was used for multivariate hazards ratios that were adjusted for the effects of location of recurrence, histologic differentiation, patient sex and age, the location of the primary tumor, and timing of disease recurrence (Group A or Group B) on survival.

Results: In all, 773 consecutive patients qualified for the analysis. The distribution of age, race, histologic differentiation, and primary tumor location was similar in both groups. The MS of Group A (n = 603 patients) and Group B (n = 170 patients) was the same (7.6 months). Similarly, the location of the primary tumor and patient sex were found to have no impact on survival. Patients with poorly differentiated tumors (World Health Organization grade 3 or 4) were found to have a shorter survival compared with those with well-differentiated or moderately differentiated tumors (grade 1 or 2; P = .004). Patients with distant metastases had a shorter survival (P = .01) than those with locoregional disease recurrence.

Conclusions: The data show that MS is similarly poor in patients with advanced gastric cancer with synchronous metastasis (Group A) or those with metachronous metastasis/disease recurrence (Group B). Poor differentiation and anatomically distant site of metastasis were found to impact MS adversely.