D1 Versus D2 Lymphadenectomy in High Risk Elderly With Gastric Adenocarcinoma

Background Although worldwide incidence of gastric cancer has decreased, it still remains the fourth most common type of cancer and the second leading cause of cancer-related death, with a growing prevalence in the elderly owing to increased life expectancy. The Literature often shows limited and discordant data regarding the prognostic value of age in gastric-cancer patients. Generally, disease-specific survival does not seem to be worse in the elderly when compared with younger patients. This evidence leads to the standardization of surgery in gastric cancer patients, whatever the age (and comorbidity). Gastrectomy with extended lymphadenectomy for non-early tumors is considered the "standard" surgical therapy for operable patients, despite any age- or comorbidity-related limitations. Following the initial doubts concerning its safety in the first randomized controlled studies, extended lymphadenectomy in gastric-cancer surgery now shows good results. Recent trials, minimizing the impact of nodal dissection on early postoperative outcome, showed a survival benefit for extended nodal dissection compared with the more limited method, particularly in advanced stages. Some of these studies showed age (and comorbidities) to be a relevant predictor of postoperative complications, conditioning the safety of the surgical procedure itself.

In a retrospective multicenter study, we examined 1.322 non-metastatic gastric-cancer patients that underwent curative gastrectomy with D2 versus D1 lymphadenectomy from January 2000 to December 2009. Postoperative complications, overall survival (OS), and disease-specific survival (DSS) according to age and the Charlson Comorbidity Score (CCS) were analyzed in relation to the extent of lymphadenectomy.

Postoperative morbidity was 30.4%. Complications were more frequent in high-morbidity elderly patients, and, although general morbidity rates after D2 and D1 lymphadenectomy were similar (29.9% and 33.2%, respectively), they also increased following D2 in high-morbidity elderly patients (39.6%). D2-lymphadenectomy significantly improved 5-year OS and DSS (48.0% vs. 37.6% in D1, p<0.001 and 72.6% vs. 58.1% in D1, p<0.001, respectively) in all patients. In elderly patients, this benefit was present only in 5-year DSS. D2 nodal dissection induced better 5-year OS and DSS rates in elderly patients with positive nodes (29.7% vs. 21.2% in D1, p=0.008 and 47.5% vs. 30.6% in D1, p=0.001, respectively), although it was present only in DSS when high-morbidity elderly patients were considered.

Even if promising, these results are derived by a retrospective study with some unavoidable biases: particularly, the selection bias depending on the choice of surgeons to perform a D1 in most elderly considered in the analysis (23.8% vs 14.4% of D1 in younger patients, p<0.001) and the unmeasurable effect of the adjuvant treatments.

Hence, a phase-III randomized controlled trial could be useful to obtain reliable data about relevant topic.

Rationale With the aging of world population, in next years we will have to face with a greater number of elderly patients. Actually, also concerning gastric cancer, this part of population is usually excluded from clinical trial, and hence guidelines are not "tested" for them. Many retrospective studies (including our retrospective analysis on a very large series) did not solve any doubt about short-term outcomes and survival benefit of D2 gastrectomy in high-risk elderly patients. Evident methodological limitations limit the relevance of their conclusions. Firstly, the retrospective design of these studies implies non-homogeneous groups, unavoidably influenced by the different cut-offs used for "elderly" definition and by the surgeons' choice with particular regard to lymphadenectomy. Secondly, they often did not consider any adjuvant therapy: although analysis would have been influenced by the administration of different regimens with different schedules, survival might have been modified, thus conditioning the interpretation of results. According the results of these retrospective reports extended lymphadenectomy confirmed its efficacy in determining better survival rates in gastric cancer patients. However, after extended nodal dissection OS in high-morbidity elderly patients, even with nodal involvement, does not present undoubted benefits. Most of these studies did not have sufficient power to validate their conclusions.

In conclusion, this prospective randomized multicenter trial will test the effect of extension of lymphadenectomy on the particular setting of high-risk elderly patients in the attempt to identify those patients most likely to benefit from aggressive radical surgery with acceptable perioperative risk.

STUDY DESIGN This is a multicenter, open randomized trial