Preoperative chemotherapy could modify recurrence patterns through postoperative complications in patients with gastric cancer.

PURPOSE: Postoperative infectious complications have a negative impact on survival outcomes in patients with gastric cancer. It is recently reported that preoperative chemotherapy may eliminate this negative impact. This study aimed to confirm whether preoperative chemotherapy can eliminate the negative impact of postoperative infectious complications (IC) on survival outcomes and elucidate the association between postoperative infectious complications and recurrence patterns. METHODS: We retrospectively reviewed data of 86 patients who received preoperative chemotherapy with docetaxel, cisplatin, and S-1 followed by R0 gastrectomy at the Kitasato University between 2006 and 2016. Patients who developed grade II or higher infectious complications during hospitalization were grouped into the IC group, while others were grouped into the non-IC (NIC) group. Survival outcomes and recurrence patterns were analyzed between the two groups. RESULTS: Infectious complications with Clavien-Dindo classification of grade II or higher were found in 12 patients (14.0%, IC group). The median observational period was 61 months. Overall survival and progression-free survival were similar in the IC and NIC groups. Recurrence occurred in 39 patients. The proportions of peritoneal and lymph node recurrences were not significantly different between the two groups. However, the proportion of distant metastasis in the IC group was significantly higher than that in NIC group (3/4 [75%] vs. 9/35 [17%], p = 0.04). CONCLUSIONS: Pathological stage after neoadjuvant therapy plays a stronger role in recurrence than postoperative complications. Lymph node and peritoneal metastasis may be suppressed by preoperative chemotherapy.

Robust vascular invasion concurrent with intense EGFR immunostaining can predict recurrence in patients with stage IB node-negative gastric cancer.

PURPOSE: The prognosis of most patients with stage IB node-negative gastric cancer is good without postoperative chemotherapy; however, about 10% suffer recurrence and inevitably die. We conducted this study to establish the optimal indications for postoperative adjuvant chemotherapy in patients at risk of recurrence. METHODS: The subjects of this retrospective study were 124 patients with stage IB node-negative gastric cancer, who underwent gastrectomy at the Kitasato University East Hospital, between 2001 and 2010. We reviewed EGFR immunohistochemistry (IHC) as well as clinicopathological factors. RESULTS: Of the 124 patients, 47 (38%) showed intense EGFR IHC (2+ or 3+), with significantly less frequency than in stage II/III advanced gastric cancer (p < 0.001). According to univariate analysis, intense EGFR IHC was significantly associated with relapse-free survival (RFS) (p = 0.023) and associated with overall survival (OS) (p = 0.045) as well as vascular invasion (p = 0.031). On the multivariate Cox proportional hazards model, intense EGFR IHC(p = 0.016) was an independent prognostic predictor for RFS, and both vascular invasion (p = 0.033) and intense EGFR IHC (p = 0.031) were independent prognostic predictors for OS. The combination of both factors increased the risk of recurrence (p = 0.001). CONCLUSIONS: In stage IB node-negative gastric cancer, vascular invasion and intense EGFR IHC increase the likelihood of recurrence. We recommend adjuvant chemotherapy for such patients because of the high risk of metachronous recurrence.

Prognostic impact of venous invasion in stage IB node-negative gastric cancer.

BACKGROUND: Little is known about risk factors for recurrence in stage IB gastric cancer without lymph node metastasis. The aims of this study were to determine prognostic factors associated with long-term survival and to clarify patterns of recurrence. METHODS: We retrospectively reviewed the medical records of 130 patients with primary gastric cancer who underwent gastrectomy at Kitasato University East Hospital from 2001 through 2010 and analyzed clinicopathological characteristics associated with survival and patterns of recurrence. RESULTS: Of the 130 patients, 12 (9.2%) had recurrence, among whom 10 (83%) patients died. Four patients (3.1%) died of other diseases. The 5-year overall survival rate was 89%. Of the 12 patients with recurrence, 7 (58%) had liver metastasis, 3 (25%) had distant lymph-node metastasis, 2 (17%) had peritoneal dissemination, and 1 (8.3%) had locoregional recurrence. Patients with tumors more than 5 cm in diameter tended to have recurrence within 1 year. Patients who had recurrence more than 2 years after surgery tended to survive for longer than 5 years after recurrence. Moderate or marked venous invasion (v2 or v3) and age >65 years were significantly associated with relapse-free and overall survival on univariate analysis. On multivariate analysis, the only independent prognostic factor for relapse-free and overall survival was venous invasion. CONCLUSIONS: Moderate or marked venous invasion (v2 or v3) is an independent predictor of relapse-free and overall survival in stage IB node-negative gastric cancer. Postoperative adjuvant chemotherapy, currently not given to this subgroup of patients, may improve the outcomes of patients with stage IB node-negative gastric cancer, particularly when accompanied by venous invasion.

Haploinsufficiency by minute MutL homolog 1 promoter DNA methylation may represent unique phenotypes of microsatellite instability-gastric carcinogenesis.

Promoter DNA methylation of MutL homolog 1 (MLH1) is considered to play a causative role in microsatellite instability (MSI) carcinogenesis in primary gastric cancer, and a high MSI status is associated with treatment sensitivity to human cancers. Nevertheless, clinicopathological analysis is defective for MLH1 methylation status in a quantitative manner. We newly developed quantitative methylation specific PCR using a TaqMan probe and applied it to 138 patients with primary gastric cancer who underwent gastrectomy in addition to basic molecular features such as MSI, Epstein Barr virus, and other DNA methylation status. (1) In primary gastric cancer, median methylation value was 0.055, ranging from 0 to 124.3. First, MLH1 hypermethylation was strongly correlated with MSI-High/MSI-Low status and suppressed immunostaining (P < 0.0001). (2) The MLH1 hypermethylation was associated with advanced age (P = 0.0048), antral location (P = 0.0486), synchronous multiple gastric cancer (P = 0.0001), and differentiated histology (P = 0.028). (3) Log-rank plot analysis identified the most relevant cut-off value (0.23) to reflect gentle phenotypes in MLH1 hypermethylation cases (P = 0.0019), especially in advanced gastric cancer (P = 0.0132), which are designated as haploinsufficiency of MSI (MSI-haplo) phenotype in this study. (4) In synchronous multiple gastric cancer, MLH1 hypermethylation was not necessarily confirmed as field cancerization. (5) MSI-haplo defined by MLH1 methylation status represented distinct prognostic phenotype even after molecular classifications. MLH1 hypermethylation designated as MSI-haplo may represent unique prognostic phenotype during gastric carcinogenesis.