Published online Jan 15, 2018. doi: 10.4251/wjgo.v10.i1.31
Peer-review started: September 7, 2017
First decision: October 9, 2017
Revised: November 24, 2017
Accepted: December 13, 2017
Article in press: December 13, 2017
Published online: January 15, 2018
In view of the limited evidence regarding T4bN1-3M0/TxN3bM0 GC, as well as the difficulty of achieving R0 resection and the high risk of disease recurrence, this retrospective study is complementary to large-scale phase III prospective trials and may provide implications for clinical practice.
The population targeted in our study is difficult to treat with no accepted standard of care. This study is the largest retrospective analysis of the effect of adjuvant therapy on patients with T4bN1-3M0/TxN3bM0 GC. Furthermore, our study explored the patterns of recurrence and their relationships to the prognosis of these patients.
To provide evidence regarding the postoperative treatment of patients with T4bN1-3M0/TxN3bM0 gastric cancer, for which guidelines have not been established.
Patients who had undergone curative resection between 1996 and 2014 with a pathological stage of T4bN1-3M0/TxN3bM0 for gastric cancer were retrospectively analyzed; staging was based on the 7th edition of the American Joint Committee on Cancer staging system. The clinicopathological characteristics, administration of adjuvant chemotherapy, and patterns of recurrence were studied. Univariate and multivariate analyses of prognostic factors were conducted. The chemotherapeutic agents mainly included fluorouropyrimidine, platinum and taxanes, used as monotherapy, doublet, or triplet regimens. Patterns of first recurrence were categorized as locoregional recurrence, peritoneal dissemination, or distant metastasis.
The 5-year overall survival (OS) of the whole group (n = 176) was 16.8%, and the median OS was 25.7 mo (95%CI: 20.9-30.5). Lymphovascular invasion and a node positive rate (NPR) ≥ 0.8 were associated with a poor prognosis (P = 0.01 and P = 0.048, respectively). One hundred forty-seven (83.5%) of the 176 patients eventually experienced recurrence; the most common pattern of the first recurrence was distant metastasis. The prognosis was best for patients with locoregional recurrence and worst for those with peritoneal dissemination. Twelve (6.8%) of the 176 patients did not receive adjuvant chemotherapy, while 164 (93.2%) patients received adjuvant chemotherapy. Combined chemotherapy, including doublet and triplet regimens, was associated with a better prognosis than monotherapy, with no significant difference in 5-year OS (17.5% vs 0%, P = 0.613). The triplet regimen showed no significant survival benefit compared with the doublet regimen for 5-year OS (18.5% vs 17.4%, P = 0.661). Thirty-nine (22.1%) patients received adjuvant chemotherapy for longer than six months; the median OS in patients who received adjuvant chemotherapy for longer than six months was 40.2 mo (95%CI: 30.6-48.2), significantly longer than the 21.6 mo (95%CI: 19.1-24.0) in patients who received adjuvant chemotherapy for less than six months (P = 0.001).
Patients with T4bN1-3M0/TxN3bM0 gastric cancer showed a poor prognosis, with the most common pattern of first recurrence being distant metastasis rather than locoregional recurrence. Adjuvant chemotherapy for longer than six months may improve the outcomes of this patient group.
To date, few retrospective studies have analyzed the survival and prognosis factors for T4bN1-3M0/TxN3bM0 GC patients; however, due to the small sample sizes and different treatment regimens, the results have been mixed. No meta-analyses have been conducted on this topic. However, a prospective randomized controlled study will be required to confirm these findings and to improve the outcomes for patients with T4bN1-3M0/TxN3bM0 gastric cancer.