Multimodal treatment of gastrointestinal tract tumors: consequences for surgery

Tissue tolerable plasma (TTP) induces apoptosis in pancreatic cancer cells in vitro and in vivo

Background

The rate of microscopic incomplete resections of gastrointestinal cancers including pancreatic cancer has not changed considerably over the past years. Future intra-operative applications of tissue tolerable plasmas (TTP) could help to address this problem. Plasma is generated by feeding energy, like electrical discharges, to gases. The development of non-thermal atmospheric plasmas displaying spectra of temperature within or just above physiological ranges allows biological or medical applications of plasmas.

Methods

We have investigated the effects of tissue tolerable plasmas (TTP) on the human pancreatic cancer cell line Colo-357 and PaTu8988T and the murine cell line 6606PDA in vitro (Annexin-V-FITC/DAPI-Assay and propidium iodide DNA staining assay) as well as in the in vivo tumour chorio-allantoic membrane (TUM-CAM) assay using Colo-357.

Results

TTP of 20 seconds (s) induced a mild elevation of an experimental surface temperature of 23.7 degree Celsius up to 26.63+/−0.40 degree Celsius. In vitro TTP significantly (p=0.0003) decreased cell viability showing the strongest effects after 20s TTP. Also, TTP effects increased over time levelling off after 72 hours (30.1+/−4.4% of dead cells (untreated control) versus 78.0+/−9.6% (20s TTP)). However, analyzing these cells for apoptosis 10s TTP revealed the largest proportion of apoptotic cells (34.8+/−7.2%, p=0.0009 versus 12.3+/−6.6%, 20s TTP) suggesting non-apoptotic cell death in the majority of cells after 20s TTP. Using solid Colo-357 tumours in the TUM-CAM model TUNEL-staining showed TTP-induced apoptosis up to a depth of tissue penetration (DETiP) of 48.8+/−12.3μm (20s TTP, p<0.0001). This was mirrored by a significant (p<0.0001) reduction of Ki-67+ proliferating cells (80.9+/−13.2% versus 37.7+/−14.6%, p<0.0001) in the top cell layers as well as typical changes on HE specimens. The bottom cell layers were not affected by TTP.

Conclusions

Our data suggest possible future intra-operative applications of TTP to reduce microscopic residual disease in pancreatic cancer resections. Further promising applications include other malignancies (central liver/lung tumours) as well as synergistic effects combining TTP with chemotherapies. Yet, adaptations of plasma sources as well as of the composition of effective components of TTP are required to optimize their synergistic apoptotic actions.

Lymph node metastasis from cancer of the esophagogastric junction, and determination of the appropriate nodal dissection

PURPOSE

Both squamous cell carcinomas and adenocarcinomas can develop in the esophagogastric junction. To clarify the appropriate lymph node dissection range, lymph node metastases from cancers in the esophagogastric junction were investigated.

METHODS

The nodal metastases were analyzed in 64 patients with squamous cell carcinoma and 129 with adenocarcinoma according to Siewert's classification, which is based on topographic anatomical criteria for adenocarcinoma.

RESULTS

The squamous cell carcinomas located above the esophagocardial junction had more frequent metastasis to the lower and middle mediastinal lymph nodes in proportion to the depth of the tumor. Nodal metastasis was also often detected in the abdominal lymph nodes. In contrast, adenocarcinomas metastasized less frequently to the mediastinal lymph nodes, and the metastatic rates in the abdominal nodes were higher than those from squamous cell carcinoma.

CONCLUSION

Esophagectomy with mediastinal and abdominal lymph node dissection is considered to be an appropriate approach for surgical resection of squamous cell carcinomas, whereas transhiatally extended gastrectomy with lower mediastinal and abdominal lymph node dissection is recommended for the treatment of adenocarcinomas.

[Neoadjuvant therapy in the upper gastro-intestinal tract. Modern strategies for Barrett's cancer]

While primary surgical resection with systematic lymphadenectomy remains the treatment of choice for locoregional Barrett's cancer, neoadjuvant chemotherapy is an increasingly accepted treatment modality for patients with locally advanced tumors and patients with extensive lymphatic spread. In contrast to neoadjuvant radiochemotherapy preoperative chemotherapy alone does not seem to increase peri-operative complications and mortality. Responders to pre-operative treatment clearly have a survival advantage as compared to those who do not respond. The use of positron emission tomography to measure changes in glucose metabolism of the primary tumor can predict response early after initiation of neoadjuvant chemotherapy and thus help to select patients who will or will not benefit from this approach. The best treatment strategy for non-responders to neoadjuvant therapy remains to be defined.

Neoadjuvant chemotherapy with a combination of docetaxel, cisplatin, fluorouracil, and leucovorin in nonresectable advanced gastric cancer: a short communication

The aim of this study was to evaluate the efficacy and toxicity of docetaxel (TAX), cisplatin (CDDP), and fluorouracil (5-FU) plus leucovorin (CF) as the neoadjuvant chemotherapy (NACT) regimens in the treatment of nonresectable advanced gastric cancer. Twelve patients with nonresectable advanced gastric cancer were treated with NACT regimens consisted of docetaxel, cisplatin, fluorouracil, plus leucovorin before operation. Nine of the 12 patients were downstaged and 8 were radically operated after the end of the NACT. The overall response rate was 75% with 8.3% complete response and 66.7% partial response, and the ascites disappeared in 63.6%. The most common toxicities were bone marrow suppression, nausea, vomiting, alopecia, and heptoses. The toxicities were recoverable after symptomatic treatment. The results confirmed that the combination of docetaxel, cisplatin, fluorouracil plus leucovorin (CF) is a very effective and well-tolerated regimen as NACT for the patients with nonresectable advanced gastric cancer.

[Change in surgical treatment of esophageal cancer in the course of the past 50 years]

Oesophageal surgery--apart from sporadic attempts--has a history of about fifty years. It was traditionally fallen into the realm of thoracic surgery developing collaterally and accomplished by the development of anaesthesiology and perioperative care. Initial surgery of the oesophagus begun by procedures aimed at tumours of the lower third and those of the gastroesophageal junction and the cardia. Surgical procedures for esophageal cancer became widespread by 1970's, leading to establishment of oesophageal surgical centres. Partial resections were succeeded by subtotal resections by 1980's. Hypopharyngeal and cervical oesophageal tumours were routinely extirpated in specialized centres by the 1990's. Extended lymph node dissection became routine and generally accepted. By the end of the decade, the importance of neoadjuvant radio-chemotherapy was highlighted and became inevitable. Growing experience of open transthoracic and blunt transhiatal resections without thoracotomy led to the onset of early thoracoscopic and laparoscopic procedures. The current practice for intraepithelial neoplasms is a minimally invasive procedure, such as endoscopic mucosectomy beside blunt transhiatal resection without thoracotomy. In case of submucosal tumours transthoracic or transhiatal blunt subtotal resections are recommended with 2-field lymphadenectomy. Solely subtotal resection with 2- or 3-field lymphadenectomy can be considered as curative intervention for advanced stage T2 cancer. In cases of T3 and T4 mid, or upper third and cervical neoplasms neoadjuvant radio-chemotherapy is recommended. Curative resection is only considered for responders.

Surgical management of esophagogastric junction tumors

Surgical resection with lymphadenectomy is the mainstay of treatment for all resectable esophagogastric junction tumors, prior to systemic generalization of the disease. This makes accurate pre-treatment staging and classification of the tumors most demanding. A well-established and internationally accepted classification for adenocarcinomas of the esophagogastric junction (AEG) helps to choose the appropriate surgical approach and to make results from different institutions comparable. Distal esophageal adenocarcinomas (AEGI) are distinguished from true cardia carcinomas (AEG II) and subcardiac gastric cancers (AEG III). Substantial advancements in this surgical field during the preceding decades have clearly revealed that individualization of the surgical strategy is the key to successfully approaching these entities. In this review we discuss the surgical management of esophagogastric junction tumors with a tailored surgical strategy.

Response to neoadjuvant chemotherapy and effects of tumor regression in gastric cancer

AIMS

Aim of this study is the evaluation of the effects induced by neoadjuvant chemotherapy (NACT) and its impact on survival on a series of locally advanced gastric carcinomas.

METHODS

Downstaging was assessed comparing pre-treatment clinical and laparoscopic staging with post-operative pathologic staging on 30 consecutive patients who completed a 3-year follow-up. Tumor downstaging and the grade of pathologic response were included in a statistical correlation between tumor regression induced by NACT and 3-year survival.

RESULTS

In this series tumor downstaging was obtained in 13 out of 30 patients. After the completion of 3-year follow-up, overall survival was >37.5months with an overall survival rate of 56.7%; this figure reached up to 70.8% in those cases who benefited from a R0-resection (24/30 patients: R0-resection rate 80.0%).

CONCLUSIONS

In this study the 3-year survival for locally advanced gastric cancer treated by NACT prior to "D2" surgical resection, compares favourably with historical series treated by surgery alone. Patients who obtained T-downstaging and subsequently benefited from a R0-resection had a definitely better chance of cure, according to a complete 3-year follow-up.

Ösophagektomie als chirurgisches Therapieprinzip beim Plattenepithelkarzinom des Ösophagus

The fatalistic approach towards surgical therapy of esophageal squamous cell cancer has been replaced in recent years by a more differentiated view. This was triggered by the establishment of individualized therapeutic modalities based on tumor stage, tumor location, general patient status, and comorbidity. Despite advances in nonsurgical therapy of squamous cell esophageal cancer, esophagectomy remains the central therapeutic modality. Primary subtotal en-bloc esophagectomy with lymphadenectomy is the only curative option with a high likelihood of success for resectable tumors (uT1-3 categories) located below the level of the tracheal bifurcation and for early more proximal tumors. In patients with locally advanced tumors at or above the level of the tracheal bifurcation, surgical resection can still cure those who respond to neoadjuvant radiochemotherapy. Preoperative "conditioning" of risk patients, surgical safety strategies in risk situations, and standardization of both the operative procedure and the perioperative management have resulted in a marked reduction of the previously substantial postoperative mortality to below 3% in experienced centers. In our own experience of 900 esophagectomies for squamous cell esophageal cancer, the 5-year survival rate rose from about 20% to more than 50% in the last two decades. Esophagectomy thus has become a safe operation and remains the only therapeutic option offering cure for a substantial proportion of patients with squamous cell cancer of the esophagus.