Upper gastrointestinal contrast radiology or endoscopy usually establishes the diagnosis of gastric cancer.
Once the diagnosis is confirmed the next question is the extent of the disease.
The key aims of staging gastric cancer are: to rule out distant metastasis; to determine recurrence risk by assessing the loco-regional ( T and N ) stage; to establish the opportunity of a neoadjuvant therapeutic approach.
Precise preoperative staging is mandatory in neoadjuvant trials, in order to compare the results of different treatments, identify subgroups of patients that will benefit most, and prevent over treatment in patients who will clearly not benefit.
In the neoadjuvant treatment setting, staging must correctly identify 1) incurable tumors with distant metastatic disease and 2) high risk tumors with serosal infiltration.
Patients with stage M1 gastric cancer have no meaningful chance of cure, and should be offered some form of palliative therapy.
Ajani et al, Fink et al. and Kelsen et al. make the case that, because of the poor prognosis associated with peritoneal carcinomatosis and the inefficacy of neoadjuvant therapy in this situation, these patients should be excluded from trials of neoadjuvant chemotherapy.
Determining the pretreatment T stage is important since it is of prognostic value and more easily 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 require further refinement: tumors confined to the muscolaris propria have better survival than tumors invading the subserosa. Published reports to date support the combined use of EUS or LUS as the most accurate methods to assess T stage.
Because of the natural progression of this disease the risk of finding peritoneal implants ( M1 disease ) at the time of laparotomy is 25-37% after an otherwise unremarkable CT scan. Considering the fact that few patients with M1 disease actually develop surgical bleeding or significant gastric outlet obstruction prior to death a strong argument can be made for laparoscoping all patients with advanced gastric cancer ( 1, 2, 3, 4 ).
Until recently preoperative staging was inaccurate in a third or more of primary cases. Decisions about adjuvant treatment were made based on intraoperative and histologic examination of the specimen, which hampered the development of neoadjuvant approaches ( 1 ).
Fung reaffirming that staging of gastric adenocarcinoma is important for comparing aspects of the disease in Asia and in the Western countries, and that it may be used to direct the treatment strategy, examines the accuracy of the textbooks and dedicated review journals at this regard.
A survey of 13 popular current surgical textbooks and review journals finds a high level of inaccuracy; this level of inaccuracy leads to confusion for the reader and to difficulty interpreting other relevant literature ( 5 ).
References
1) J Tschmelitsch, M R Weise, M S Karpeh. Modern staging in gastric cancer. Surgical Oncology, 2000; 9, 23-30.
2) Ajani et al. potentially resectable gastric canrcinoma : current approaches to staging and preoperative therapy. World Journal Surgery, 1995; 19: 216-20.
3) Fink U et al. Neoadjuvant chemotherapy for gastric cancer. W J Surg 1995; 19: 509-16.
4) Kelsen DP. Adjuvant and neoadjuvant therapy for gastric cancer. Seminars in Oncology. 1996; 6 (7): 664-70.
5) Anthony SY Fung. Accuracy of current educational literature on the staging of gastric carcinoma. World Journal Surgery 21,237-239,1997.
