New research presented at the Gastrointestinal (GI) Cancers Symposium from the American Society of Clinical Oncology, or ASCO, from January 22-24, 2010 in Orlando addressed key issues on the prevention, screening, and treatment of GI cancers. The features below highlight just some of the studies that emerged from the symposium.
Comparing Treatments for True Cardia & Sub-Cardia Cancer
The Particulars: Different surgical treatments are available for the treatment of true cardia and sub-cardia cancer. In left thoracoabdominal (LT) approaches, surgeons make a large incision from the left side of the chest to the middle of the abdomen. In abdominal and transhiatal (AT) approaches, the incision is smaller in the upper abdomen. The AT approach does not provide as much space to remove lymph nodes for analysis as the LT approach, but it is less invasive.
Data Breakdown: Researchers randomly assigned 167 patients to undergo surgery with AT or LT between 1995 and 2003. After a medium follow-up of 7.7 years, 5-year survival rates were higher in the AT group than the LT group (51% vs 37%). AT recipients experienced significantly less deterioration in respiratory function, body weight, and other symptoms.
Take Home Pearl: When surgical treatment is indicated in true cardia or sub-cardia cancer, AT approaches appear to be superior to LT approaches.
Predicting Survival in Gastric Cancer
The Particulars: Peritoneal cytology is often used to determine the presence of cancer spread in gastric cancer patients that is not visible to the naked eye. It is performed by microscopic examination of cell samples collected during surgery.
Data Breakdown: A study was conducted to analyze poor disease-specific survival (DSS) among patients with gastric cancer. Positive peritoneal cytology in the abdominal cavity predicted poor DSS, even in the absence of visible peritoneal or visceral metastases. About half of patients selected for repeat staging laparoscopy with positive peritoneal cytology who were initially treated with chemotherapy before surgical resection were converted to negative peritoneal cytology patients. These patients had significantly longer DSS than those that did not convert (2.5 years vs 1.4 years).
Take Home Pearl: The presence of microscopic cancer cells in positive peritoneal cytology appears to predict poor DSS among gastric cancer patients.
An New Approach to Preventing Colorectal Cancer?
The Particulars: Polyamines have been associated with cell growth and cancer development. Food products rich in polyamines include orange juice, meat, green peas, and corn. Previous research has shown that a polyamine-inhibiting regimen of difluoromethylornithine (DFMO) plus sulindac can prevent precancerous colorectal adenomas.
Data Breakdown: A randomized, phase III clinical trial investigated the role of dietary intake of polyamines and the efficacy of DFMO/sulindac for preventing adenomas in 188 patients. Those with the highest dietary polyamine intake were more likely to have colorectal adenomas greater than 1 cm and advanced adenomas when compared with those who had the lowest dietary polyamine intake (43.6% vs 26.4%, and 52.7% vs 35.9%, respectively). DFMO/sulindac treatment, however, only reduced adenoma risk in patients with lower intake of dietary polyamines and not in those with higher dietary polyamine intake.
Take Home Pearl: Control of dietary intake of polyamines may be an effective adjunctive strategy to polyamine inhibitors for preventing colorectal adenomas and cancer.