Wedge Resection Apt for Gastrointestinal Stromal Tumors

08/22/16

By David Douglas

NEW YORK (Reuters Health) - With appropriate selection and on-table gastroscopy when needed, laparoscopic nonanatomic wedge resection can deal with most gastric gastrointestinal stromal tumors (GISTs), according to Canadian researchers.

As Dr. Carmen L. Mueller told Reuters Health by email, "This series demonstrates that wedge resection is feasible for gastric GISTs in challenging locations, such as the antrum and cardia. By avoiding anatomical resection, patients are spared total or subtotal gastrectomy while still achieving excellent surgical and oncologic outcomes."

In a paper online July 30 in Surgery, Dr. Mueller of St. Mary's Hospital Centre in Montreal and colleagues note that wedge resection is preferred to anatomic resection wherever possible "due to the reduction in physiologic derangement and lower risk of anastomotic leak."

However, they add, there is concern that the technique might not be "feasible or appropriate in certain anatomic locations, such as the cardia or antrum."

To examine their own performance, the team examined data on 59 patients who had undergone operative resection for GISTs between 2000 and 2014.

The procedure was completed laparoscopically in 71% of patients, was open in 24% and was converted to open in three patients. Wedge resection was performed in 54 patients (92%), and anatomic resection in the remaining five (8.5%). Median tumor size was 4.5 cm.

Tumor locations were in the fundus/body/greater curvature in 35 patients, lesser curvature in eight patients, antrum in eight patients, and cardia in eight patients.

Only three of the 16 patients with antral or cardia tumors underwent anatomic resection, and "all of these were during the early experience at our center," the authors say; 13 were removed with wedge resections and 12 of these were completed laparoscopically.

Of the cardia and antral tumors that were treated with wedge resection, the researchers add, "on-table gastroscopy was used to guide the operative approach and prevent narrowing of the gastric outlet or gastroesophageal junction in all cases."

Negative pathologic margins were achieved in all patients. Five year disease-free survival was 91% and overall survival was 95%.

"In conjunction with proper long-term follow-up and selective use of neoadjuvant/adjuvant treatment, oncologic outcomes achieved in this patient series were excellent," the researchers conclude.

Dr. Heikki Joensuu of the University of Helsinki, Finland, commended the authors on their "great paper."

"Patients presenting with a large gastric GIST are now often treated with neoadjuvant imatinib for about 6 to 9 months in an attempt to achieve organ-sparing surgery and to avoid gastrectomy," he told Reuters Health by email. "This may well succeed, but a disadvantage of (the) neoadjuvant approach is the lack of sufficient tumor tissue to carry out proper risk assessment for GIST recurrence."

"Usually only core needle tissue is available from patients who are treated with neoadjuvant imatinib, which does not allow proper mitotic counting, leading to inadequate risk stratification for GIST recurrence," said Dr. Joensuu, an oncologist who studies GIST. "Risk stratification is needed when the need of adjuvant imatinib is considered. Tumor mitotic count is generally considered as the most important single prognostic factor in GIST."

SOURCE: bit.ly/2b9fH7w

Surgery 2016.

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