Because of the natural progression of this illness the risk of finding peritoneal implants (M1 illness) at the time of laparotomy is 25-37% after an otherwise, unremarkable CT scan.Thinking about the fact that few patients with M1 illness actually create surgical bleeding or significant gastric outlet obstruction prior to death a powerful argument can be made for laparoscoping all patients with advanced gastric cancer.
Moreover in order to pick patients that will most likely benefit from neoadjuvant treatment, distant metastases must be ruled out preoperatively. In the neoadjuvant treatment setting, staging must correctly identify (1) incurable tumors with distant metastatic illness and (2) high-risk tumors with serosal infiltration. Patients with stage M1 gastric cancer have no significant chance of cure, and ought to be offered some type of palliative therapy .
If the patient is due to get preoperative chemotherapy LUS is used to choose the extent of stomach wall invasion and lymph node involvement prior to treatment. These procedures identify patients with locally advanced illness (serosal invasion or obvious nodal metastases) that are at high risk for local recurrence and candidates for neoadjuvant chemotherapy trials.
Determining the pretreatment T stage is important since it is of prognostic value, and more basically verified than N stage. For T1 gastric cancers, resection alone is regarded as the treatment of choice. In T3 cancer the risk of recurrence is high and trials of neoadjuvant chemotherapy can clearly be justified. For T2 tumors decisions regarding investigational treatment may need further refinement: tumors confined to the muscularis propria, have better survival than tumors invading the subserosa. Published reports to date support the combined use of EUS or LUS as the most correct methods to assess T stage ( 2 ).
In the Yano's study only patients with T3 or T4 tumors were enrolled.With the advanced gastric cancer important findings that decide the operative indication are an unresectable T4 tumor, paraaortic node metastasis, and peritoneal dissemination. An unresectable T4 lesion and paraaortic node metastasis can be diagnosed by dynamic CT.Surgical laparoscopy offers high accuracy for detecting intraabdominal small metastases. Laparoscopic inspection is better than macroscopic examination under open laparotomy for several reasons. The subphrenic space and Douglas pouch, where peritoneal metastasis is often observed but direct observation under laparotomy misses small metastatic nodules, can be observed by laparoscopy depending on the magnifying power. Therefore, staging laparoscopy ought to be performed for patients at high risk for peritoneal metastasis, such as patients with type 4 tumors, undifferentiated tumors, or tumors in over three regions.
Several studies showed that preoperative chemotherapy induced down-staging of the disease and resulted in a higher healing resection rate for surgically staged unresectable cancer. Correct staging is necessary in advanced cases not only to settle on neoadjuvant treatment but also on whether to proceed with salvage surgical procedure after neoadjuvant treatment. A second staging laparoscopy effectively determined whether patients ought to undergo salvage surgical procedure after neoadjuvant therapy, in cases where peritoneal metastasis was the only reason for noncurability.
Staging laparoscopy also makes it feasible to perform abdominal lavage for cytologic, immunohistochemical, or molecular biologic detection of intraabdominal free cancer cells. The positive cytology of free cancer cells in the abdominal lavage liquid is an independent prognostic factor for T2 & T3/4 patients with no apparent
peritoneal seeding in the coursework of surgical procedure. Recent work with immunohistochemical staining suggests that patients with intraabdominal free cancer cells are at high risk for later diffuse metastasis. Evaluation of free tumor cells or tumor markers in the lavage liquid is a clue to detecting invisible peritoneal micrometastasis. Cancer Treatment planning for patients with positive cytology ought to be determined in future trials ( 3 ).
Siewert affirms that beyond any doubt surgical laparoscopy constitutes a step forward in surgical methodologies and contributes to improved preoperative staging, for peritoneal carcinomatosis. It ought to be used if therapeutic benefits can be gained, as is true for neoadjuvant chemotherapy. Otherwise, benefits and risks must be evaluated carefully. Irresponsible usage of surgical laparoscopy is not beneficial for the doctor or for the patient.In fact in addition to the morbidity and mortality related to surgical procedures, dissemination of tumor cells as a consequence of biopsies or other tumor manipulations could occur. Port-site metastases following diagnostic laparoscopy have been well described in the literature ( 4 ).
Luis F. Onate-Ocana et al define a three group staging method: stage I, no serosal involvement; stage II, serosal involvement; stage III, adjoining organ invasion; & stage IV, distant disease found at laparoscopy.The proposed staging method is a simplification of the TNM staging & is not intended to be a substitute. It ought to be regarde as a tool for the choice of the best therapeutic option for the specific patient & also for pretherapeutic stratification of risk factors in the setting of new randomised clinical trials ( 5, 6 ).
Rosin et al. define important technical aspects regarding diagnostic laparoscopy. The first controversial issue is its timing: it can be a separate procedure, or performed immediately before the planned healing surgical procedure. Another unresolved debate is the extent of the procedure: it ranges from inspection only, with biopsy of suspicious lesions, to extensive dissection, use of LUS, and peritoneal citology sampling ( 7 ).
