Diffuse type advanced gastric cancer showing dismal prognosis is characterized by deeper invasion and emerging peritoneal cancer cell: the latest comparative study to intestinal advanced gastric cancer.
OBJECTIVE
Diffuse type advanced gastric cancer (D-AGC) is highly malignant disorder with dismal prognosis, however the causative attribution explaining such malignancy remains fully unexplained as compared to intestinal type AGC (I-AGC).


METHODS
We examined the archive of 232 AGC with cytology test (CY) but no distant metastasis, who underwent gastrectomy in Kitasato University Hospital in order to reveal the prognostic significance of D-AGC in a multivariate approach.


RESULTS
D-AGC occupied 68% (157/232) among AGC, and showed poorer prognosis than I-AGC (p = 0.024). Multivariate prognostic analysis revealed that independent prognostic factors for AGC are CY (p < 0.0001), pN (p = 0.0068), pT (p = 0.015), and age (p = 0.012), and that histology was eliminated, suggesting that histology itself does not represent high malignancy within the identical stage. D-AGC was significantly associated with younger age (p = 0.018), female preponderance (p = 0.006), advanced pT (p = 0.0002), advanced pN (p = 0.016), and positive CY factors (p = 0.032), among which negative prognostic factors were pT, pN, and CY factors. Multivariate logistic regression analysis elucidated that both pT (serosal exposure, p = 0.013) and CY (p = 0.034) factors were finally remnant independent predictors for D-AGC among the 3 univariate negative prognostic factors, but that pN was not. Intriguingly, age could be an independent prognostic factor only in D-AGC.


CONCLUSIONS
Our research revealed for the first time that more dismal prognosis of D-AGC than I-AGC could be explained by propensity of deeper invasion and emerging peritoneal cancer cell, and histology itself did not have a prognostic value, hence indicating that present staging system works properly even in D-AGC as well as I-AGC. We must identify its molecular mechanism of both invasion and emerging peritoneal disease of D-AGC in order to improve the prognosis.
Yamashita
K
K
Department of Surgery, Kitasato University Hospital, Kitasato 1-15-1, Sagamihara 228-8555, Kanagawa, Japan.
Sakuramoto
S
S
Katada
N
N
Futawatari
N
N
Moriya
H
H
Hirai
K
K
Kikuchi
S
S
Watanabe
M
M
D000367:Age Factors; D000368:Aged; D005260:Female; D005743:Gastrectomy; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D009367:Neoplasm Staging; D010534:Peritoneal Neoplasms / Q000556:secondary*; D011379:Prognosis; D012189:Retrospective Studies; D012307:Risk Factors; D013274:Stomach Neoplasms / Q000473:pathology* / Q000601:surgery; D015996:Survival Rate