Barrett's esophagus: treatments of adenocarcinomas II

The following topics are explored in this collection of commentaries on treatments of adenocarcinomas related to Barrett's esophagus: the importance of intraoperative frozen sections of the margins for the detection of high dysplasia; the preferable way for sentinel node dissection; the current role of robotic surgery and of video-endoscopic approach; the value of the Siewert's classification of adenocarcinomas; the indications of two-step esophagectomy; the evaluation of pathological complete response; the role of PET scan in staging and response assessment; the role of p53 in the selection of adenocarcinomas patients; chemotherapy regimens for adenocarcinomas; the use of monoclonal antibodies in the control of cell proliferation; he attempt to define a stage-specific strategy, and the possible indications of selective therapy; and changes in mortality rates from esophageal cancer.

Low-dose taxotere enhances the ability of sorafenib to induce apoptosis in gastric cancer models

Despite the low efficacy of conventional antitumour drugs, chemotherapy remains an essential tool in controlling advanced gastric and oesophageal cancers. We aimed to provide a biological rationale based on the sorafenib-taxotere interaction for the clinical treatment of gastric cancer. In vitro experiments were performed on four human gastric cancer cell lines (GK2, AKG, KKP and NCI-N87). Cytotoxicity was evaluated by sulforhodamine B (SRB) assay, cell cycle perturbations, apoptosis and mitotic catastrophe were assessed by flow cytometric and microscopic analyses, and protein expression was studied by Western blot. In the in vivo experiments, nude mice xenografted with the most resistant line were treated with sorafenib and docetaxel singly or in association. Sorafenib inhibited cell growth (IG(50) values ranged from 3.4 to 8.1 μM) and caused down-regulation of MAP-K/ERK phosphorylation and of mcl-1 and p-bad expression after a 48-hr exposure. Apoptosis induction was associated with caspase-3 and -9 activation and mitochondrial membrane depolarization. The drug combination enhanced apoptosis (up to 80%) and produced a synergistic interaction when low doses of the taxane preceded administration of the antityrosine kinase. This synergism was probably due to the induction of an anomalous multidiploid G0-G1 peak and to consequent mitotic catastrophe, which increased sensitivity to sorafenib. Consistent with in vitro results, the docetaxel-sorafenib sequence exhibited high therapeutic efficacy in NCI-N87 mouse xenografts producing tumour weight inhibition (> 65%), tumour growth delay (up to 25 days) and increased mouse survival (30%). Our findings suggest the potential clinical usefulness of treatment with sorafenib and docetaxel for advanced gastric cancer.

Multidisciplinary management of gastric and gastroesophageal cancers

Carcinomas of the stomach and gastroesophageal junction are among the five top leading cancer types worldwide. In spite of radical surgical R0 resections being the basis of cure of gastric cancer, surgery alone provides long-term survival in only 30% of patients with advanced International Union Against Cancer (UICC) stages in Western countries because of the high risk of recurrence and metachronous metastases. However, recent large phase-III studies improved the diagnostic and therapeutic options in gastric cancers, indicating a more multidisciplinary management of the disease. Multimodal strategies combining different neoadjuvant and/or adjuvant protocols have clearly improved the gastric cancer prognosis when combined with surgery with curative intention. In particular, the perioperative (neoadjuvant, adjuvant) chemotherapy is now a well-established new standard of care for advanced tumors. Adjuvant therapy alone should be carefully discussed after surgical resection, mainly in individual patients with large lymph node positive tumors when neoadjuvant therapy could not be done. The palliative treatment options have also been remarkably improved with new chemotherapeutic agents and will further be enhanced with targeted therapies such as different monoclonal antibodies. This article reviews the most relevant literature on the multidisciplinary management of gastric and gastroesophageal cancer, and discusses future strategies to improve locoregional failures.

Esophageal cancer: adjuvant therapy

In the United States, esophageal cancer is an uncommon but aggressive malignancy. Prior research has focused on the incorporation of chemotherapy and radiotherapy in both the pre- and postoperative setting. Both squamous cell and adenocarcinoma histologies have been treated in trials, with adenocarcinoma now the predominant histology seen in the United States. Although preoperative chemotherapy improves survival compared with surgery alone, the addition of concurrent radiotherapy to preoperative chemotherapy improves rates of curative resection, reduces local tumor recurrence, and achieves a significant rate of pathologic complete response. Combined preoperative chemoradiotherapy is the preferred preoperative strategy for locally advanced esophageal cancers in the United States. Definitive chemoradiotherapy alone appears to be equivalent in terms of overall survival compared with chemoradiotherapy followed by surgery in squamous cancers, although the addition of surgery after chemoradiotherapy may afford superior local control of disease. Postoperatively, survival is improved with postoperative chemotherapy and radiotherapy in adenocarcinoma of the gastroesophageal junction, if none has been delivered preoperatively. Ongoing research involves evaluating regimens with newer chemotherapeutic drugs, such as paclitaxel or irinotecan, as well as the incorporation of targeted molecular therapies.

Docetaxel in the treatment of gastric cancer

Docetaxel is part of the standard chemotherapy in breast, non-small cell lung cancer and androgen-independent metastatic prostate cancer and has recently been approved for advanced gastric cancer. It demonstrated promising single-agent efficacy in gastric cancer and was therefore investigated in different combination regimens. The combination of docetaxel with 5-fluorouracil (5-FU), capecitabine, irinotecan or cisplatin demonstrated high efficacy. The triple combination of docetaxel/cisplatin and 5-FU (DCF) was investigated in randomized Phase II trials and a randomized Phase III study (TAX325). In TAX325, DCF demonstrated superiority in terms of time to tumor progression, response rate and survival against a cisplatin/5-FU combination. Docetaxel was therefore approved for advanced gastric cancer by the US FDA and the European Agency for the Evaluation of Medicinal Products and will evolve as an integral part of routine combination regimens against gastric cancer. This review will discuss and interpret the different Phase II and III trials of docetaxel in gastric cancer.