Introduction
The sex differences in the incidence of gastric cancer have been well known. However, uncertainty still exists in terms of prognosis of GC. For example, the US SEER data reports a significantly better prognosis in females than in males, but the prognosis is better in males than in females in Korean Central Cancer Registry data. Roles of molecular markers and gut microbiota as new prognostic factor are emerging recently, but few studies seem to try to reveal sex differences.
Aims & Methods
In this background, we aimed to analyze the differences in GC characteristics according to sex in Korean patients, mainly focused on survival. This was a single-center retrospective study. A total of fifteen thousand patients diagnosed with GC at the Seoul National University Bundang Hospital between 2003 and 2023 were included. Clinicopathological characteristics, histologic types, survival rates with age- and stage-stratification, and associated risk factors were analyzed. Information related to death was cross-verified using medical record review and data from the National Statistical Office.
Results
The ratio of males and females was about 2:1, and there was no differences in stage between sexes. Female patients were significantly younger than males, had more gastric body cancers and tumors with diffuse type or poorly differentiated histology. Females underwent less endoscopic treatment and more surgery, and tumors with microsatellite instability was more common in females, while mutation of p53 was less common. In histological types according to Lauren classification, diffuse type histology was more common in younger patients in both males and females. The proportion of intestinal type GC increased with age, but the proportion increased rapidly in males while increased gradually in females. In Cox multivariate regression analysis for GC-related death, older age, proximal tumor location, diffuse type histology and advanced tumor stage were risk factors. In terms of survival, overall and GC-specific survival did not show significant differences between sexes in the analysis of the total population. However, sex differences in survival reversed with age, that younger females under 50 showed survival disadvantages, but the survival became similar in 50s, and older females over 60 showed survival advantages in both overall and GC-specific survival. Furthermore, in the stratification analysis according to the stage, there were no significant differences in stages I to III. But, stage IV female patients showed significant survival disadvantages. In subgroup analysis of stage IV patients, the differences between males and females in median survival were two months, and female patients were significantly younger and had a higher proportion of diffuse type GC than male patients, which shows aggressive feature and is related to poorer survival.
|
| Total
(N=1,924) (%)
| Male
(n=1,282) (%)
| Female
(n=642) (%)
| p
|
|---|
Median survival (mo)
|
| 10
| 11 | 9 | 0.022
|
Age (mean±SD)
|
| 61.59±14.25
| 62.41±13.23
| 59.96±15.97
| 0.001
|
Age (in diffuse type patients, mean±SD)
|
| 54.55±14.71
| 56.43±14.29
| 52.26±14.91
| 0.001
|
Lauren classification
| Intestinal
| 554
(48.0)
| 438
(56.7)
| 116
(30.4)
| <0.001
|
| Diffuse
| 574
(49.7)
| 315
(40.7)
| 259
(68.0)
|
|
| Mixed / Indeterminate
| 26
(2.3)
| 20
(2.6)
| 6
(1.6)
|
|
Conclusion
Significant differences in survival between sexes were observed with stratification analysis, although sex itself was not an independent prognostic factor. These age-dependent changes are thought to suggest the effect of sex hormones. These differences should be considered in clinical practice and later research in terms of tailored medicine.
