Preoperative Therapy Regimen Influences the Incidence and Implication of Nodal Downstaging in Patients with Gastric Cancer

Purpose

Nodal downstaging after preoperative therapy for gastric cancer has been shown to impart excellent prognosis, but this has not been validated in a national cohort. The role of neoadjuvant chemoradiation (NACR) in nodal downstaging remains unclear when compared with that of neoadjuvant chemotherapy alone (NAC). Furthermore, it is unknown whether the prognostic implications of nodal downstaging differ by preoperative regimen.

Materials and Methods

Using the National Cancer Database, overall survival (OS) duration was compared among natural N0 (cN0/ypN0), downstaged N0 (cN+/ypN0), and node-positive (ypN+) gastric cancer patients treated with NACR or NAC. Factors associated with nodal downstaging were examined in a propensity score-matched cohort of cN+ patients, matched 1:1 by receipt of NACR or NAC.

Results

Of 7,426 patients (natural N0 [n=1,858, 25.4%], downstaged N0 [n=1,813, 24.4%], node-positive [n=3,755, 50.4%]), 58.2% received NACR, and 41.9% received NAC. The median OS durations of downstaged N0 (5.1 years) and natural N0 (5.6 years) patients were similar to one another and longer than that of node-positive patients (2.1 years) (P<0.001). In the matched cohort of cN+ patients, more recent diagnosis (2010–2015 vs. 2004–2009) (odds ratio [OR], 2.57; P<0.001) and NACR (OR, 2.02; P<0.001) were independently associated with nodal downstaging. The 5-year OS rate of downstaged N0 patients was significantly lower after NACR (46.4%) than after NAC (57.7%) (P=0.003).

Conclusions

Downstaged N0 patients have the same prognosis as natural N0 patients. Nodal downstaging occurred more frequently after NACR; however, the survival benefit of nodal downstaging after NACR may be less than that when such is achieved by NAC.

Linitis Plastica: a Distinct Type of Gastric Cancer

BACKGROUND

The prognosis of patients with linitis plastica (LP) gastric cancer is reported to be poor. The purpose of our retrospective study was to characterize the clinicopathologic features and survival outcomes of patients with LP, using a univocal definition.

METHODS

We defined LP as gastric cancer that involves more than 1/3 of the gastric wall macroscopically. We reviewed a prospectively maintained institutional database of gastric cancer patients and summarized and compared clinicopathologic factors of patients with and without LP who had undergone gastrectomy. Patients were matched 1:1 using propensity score matching, and their overall survival (OS) rates and durations were compared. Multivariable Cox regression analyses were conducted, using gastrectomy as a time-varying covariate.

RESULTS

We identified 740 patients with radiographically non-metastatic gastric cancer, 157 (21.2%) of whom had LP. Most patients with LP had advanced-stage disease (75.8% had stage IV disease, mainly due to peritoneal involvement). Patients with LP had significantly shorter OS durations than did those without LP in the entire cohort (median OS, 14.0 vs. 33.5 months; p value < 0.001) and in the surgical cohort (median OS after gastrectomy, 21.8 vs. 91.0 months; p < 0.001), as well as in the propensity-matched surgical cohort. In the LP cohort, chemotherapy (hazard ratio [HR] = 0.594; p = 0.076), chemoradiation therapy (HR = 0.346; p = 0.001), and gastrectomy (HR = 0.425; p = 0.003) were associated with a longer OS.

CONCLUSIONS

LP is a phenotype of gastric cancer that often presents at an advanced stage, with a high rate of peritoneal involvement. The survival durations of patients with LP were poor in our study, even in the surgical cohort. The use of preoperative chemotherapy, chemoradiation therapy, and gastrectomy appeared to be important in carefully selected patients with localized LP.

Characteristics and Survival of Gastric Cancer Patients with Pathologic Complete Response to Preoperative Therapy

BACKGROUND

Pathologic complete response of a primary tumor (ypT0) after preoperative therapy is associated with improved overall survival (OS). However, whether other variables are associated with outcome for gastric cancer patients with ypT0 status is unknown.

METHODS

This study reviewed an institutional database of patients who underwent resection of gastric or gastroesophageal adenocarcinoma after preoperative therapy and identified patients with ypT0 status. Cox regression models were used to identify clinicopathologic predictors of OS.

RESULTS

Of 77 patients with ypT0 status identified in this study, 36 (47%) had gastroesophageal junction tumors. At presentation, 62 patients (81%) had clinical T3 disease, and 7 (9%) had clinical T4 disease. The clinical nodal status was positive (cN+) for 45 patients (58%). Preoperative chemoradiation was administered to 75 patients (97%). The median follow-up duration was 3.54 years. The median OS was 10 years, and the 5-year OS rate was 61%. Univariable analysis identified age of 65 years or older at the time of diagnosis, histologic grade, and ypN status as significant predictors of OS. Multivariable analysis confirmed age of 65 years or older [hazard ratio (HR), 4.26; p < 0.001] and persistent nodal disease (ypN+ status; HR, 5.12; p < 0.001) to be independently associated with OS. Clinical stage was not associated with survival. In the subset of ypT0N0 patients, no clinicopathologic feature was predictive of survival.

CONCLUSION

For gastric or gastroesophageal adenocarcinoma patients with ypT0 status after preoperative therapy, ypN+ status substantially reduced survival. Pretreatment clinical stage had no impact on OS for patients with a pathologic complete response.

Adjuvant therapy in gastric cancer: what is the optimal approach?

Gastric cancer confers a poor prognosis even when diagnosed as localized disease. Multimodality therapy improves the cure rate of patients with localized cancer. However, adjunctive therapeutic approaches differ in different regions of the world. This review focuses on the current standards and unresolved issues based on updated literature on therapy for localized gastric cancer. In the USA, the Intergroup 0116 trial established the use of postoperative chemoradiotherapy as a standard for patients who have surgery first for treatment of gastric cancer. In Europe, the MAGIC trial investigating perioperative chemotherapy demonstrated a survival benefit for gastric cancer patients. Finally, in Asia, the ACTS-GC and CLASSIC trials investigating postoperative chemotherapy established this as the standard of care after primary surgery that included D2 dissection. It is clear, however, that surgery alone is insufficient to achieve the highest possible cure rates.