DOES ADJUVANT THERAPY ASSOCIATED WITH ESOPHAGECTOMY IMPROVE SURVIVAL IN PATIENTS WITH ESOPHAGOGASTRIC JUNCTION ADENOCARCINOMA? Terapia adjuvante associada à esofagectomia melhora a sobrevida nos pacientes portadores de adenocarcinoma da junção esofagogástrica?

In the last ten years several authors have reported progressive increase in the prevalence of adenocarcinoma of the esophagus and the esophagogastric junction in occidental countries1,2,3,4 and also in some oriental ones5. The main factors involved are chronic gastroesophageal reflux, untreated Barrett’s esophagus, smoking and obesity6. The low intake of fresh fruits, vegetables and cereal fibers may raise this risk7,8,9,10. Obesity is associated with the prevalence of various types of tumors and may be an association between patterns of fat distribution and risk of malignant transformation of Barrett’s esophagus, for example. Furthermore, altered metabolic profiles in metabolic syndrome may be a key factor in the genetic/cellular changes cycle that mark the progression of Barrett’s esophagus to cancer. Surgery is the primary mode in the treatment of adenocarcinoma of the esophagus. However, the results of surgical treatment alone are limited. Another aspect to be considered is the fact that in Western countries where there is no endoscopic surveillance programs generally adenocarcinomas of the esophagogastric junction are diagnosed in advanced stages, with disease extension to the serosa or to regional lymph nodes at the moment of diagnosis. Thus, adjuvant and neoadjuvant therapies have attracted the interest of several research groups in order to improve survival rates and relatively low cure. Therefore, the increasing prevalence of this disease in the world, its association with risk factors significant for the population, their surgical treatment esophagectomy – with important risks and its poor prognosis despite the best surgical techniques, fully justify the need to study new therapeutic strategies. Adjuvant therapy is generally defined as a treatment that is given after transaction considered “curative” (R0 resection) in order to improve the chances of long term survival. Depending on the type of disease, may be adjuvant chemotherapy, radiotherapy or both. Adjuvant therapy after surgery has theoretical advantages and disadvantages. The potential advantages are: a) may or not be based on pathological staging, and in potentially inaccurate clinical staging; b) patients who might benefit from adjuvant therapy can be identified, avoiding toxicity in those who do not need or will not be benefited with this treatment; c) delay, resulting from the neoadjuvant therapy, is prevented and the resection is carried; d) dysphagia is released early in the treatment; e) nutrition can be maintained by jejunostomy performed during the operation; and f) toxicity of neoadjuvant therapy does not affect the operation. The potential disadvantages are: a) blood flow in the area of resection can be reduced and reducing the amount of chemotherapeutic agents in locoregional tumor bed; b) the therapy target for radiotherapy has been removed in the operation, complicating the definition of the fields to do it; c) postoperative surgical complications may delay adjuvant therapy; d) deaths in the immediate preoperative do not permit completion of adjuvant therapy, causing bias in survival data; and f) the effects of neoadjuvant therapy on tumor resectability are eliminated. The publication that guides adjuvant treatment is the one of Macdonald et al.4 in 2001. Was a prospective randomized study involving 556 patients with high risk of recurrence of adenocarcinoma of the stomach and the esophagogastric junction (2/3 with T3 or T4 tumors and 85% with lymph node metastases). The research evaluated the possible benefit of adjuvant chemoradiation. The median overall survival in the surgery group unique was 27 months, whereas in associated with adjuvant chemoradiation was 36 months. The authors concluded that postoperative chemoradiotherapy