The data in the study presented at the ASCO Gastrointestinal Cancers Symposium demonstrated that while rare, stage 4 gastrointestinal stromal tumors often spread to the liver.
Results of an analysis presented at the 2021 American Society of Clinical Oncology Gastrointestinal Cancers Symposium demonstrated that a rare type of advanced gastrointestinal cancer — stage 4 gastrointestinal stromal tumors — commonly presents in the small intestine and stomach, predominantly in men.
The data also demonstrated that while rare, stage 4 gastrointestinal stromal tumors often spread to the liver. However, the results also indicated that more than half of the study population with stage 4 gastrointestinal stromal tumors (51%) were alive at five years.
“Combined surgery [and] systemic therapy demonstrates best outcomes, although surgical resection alone might yield comparable results in selected patients,” Dr. Johannes Uhlig, a resident in the department of diagnostic and interventional radiology at University Medical Center Gottingen in Denmark and visiting researcher in the department of radiology and biomedical imaging at Yale School of Medicine, and colleagues wrote in the abstract.
To assess the epidemiology, treatment and outcomes of patients with stage 4 gastrointestinal stromal tumors, the study authors analyzed data from the United States National Cancer Database from 2010 to 2016. This analysis focused on 1,578 patients with invasive stage 4 gastrointestinal stromal tumors without prior malignant disease.
The number of patients in this study represented 13.3% of all patients with gastrointestinal stromal tumors. Patients were diagnosed with gastrointestinal stromal tumors at a median age of 62 years. Most patients had cancer in the stomach (55.4%) and small intestine (40%). More than half of the patients had distant organ metastases (58.7%), with the most common being hepatic, occurring in 50.8% of patients.
Most patients were treated with systemic therapy (78.6%) either combined with surgery (43.3%) or alone (35.4%). For patients who underwent surgical resection, 6.9% received neoadjuvant systemic therapy, 32% received adjuvant therapy (treatment given in addition with initial treatment) and 5.1% received a combination of both. In addition, 12.9% of patients underwent surgical resection alone.
Overall, 88% of patients with stage 4 gastrointestinal stromal tumors were alive at one year, 77% were alive at two years, 67% were alive at three years and 51% were alive at five years.
Based on multivariable Cox proportional hazard models, researchers found that primary treatment for gastrointestinal stromal tumors independently affected overall survival. Patients had shorter overall survival when treated with systemic therapy alone or no treatment, compared to treatment with surgery and systemic therapy. The difference in overall survival was not significant when patients treated with surgery and systemic therapy were compared to patients who received surgery alone. Overall survival was not statistically different when neoadjuvant, adjuvant and combined neoadjuvant and adjuvant systemic therapy was compared in subgroup analyses of patients who underwent surgical resection.
Patients treated at non-academic centers had shorter overall survival compared with those treated at academic centers. Other independent predictors of overall survival included older age, male sex, higher cancer grade, higher comorbidities and large cancer diameter.
The authors concluded by noting that stage 4 gastrointestinal stromal tumors are rare, but most commonly occur in the stomach and small intestine of men, with an “excellent” five-year overall survival rate.
A version of this story appeared on OncLive® as “Invasive Gastrointestinal Stromal Tumors More Common in Men, Initiating in the Small Intestine and Stomach.”
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