April 2012

Gastrointestinal stromal tumor associated with other primaries: A study of 154 patients

Abstract 10567, Renganayaki K. Pandurengan, MD Department of Epidemiology, University of Texas M. D. Anderson Cancer Center, Houston, TX

In a retrospective study of GIST patients treated at MD Anderson Cancer Center from 1995 through 2007, 153 of 783 (20 percent) patients were identified as having a primary cancer in addition to GIST. Although they did not include a comparison with a similar population without GIST, the authors report that the occurrence of other malignancies appears to be more common than expected. In their conclusions they state that surveillance (for other cancers) is an important component of GIST management.

The 20 percent coincidence rate observed here is within the range of other studies of secondary cancer in GIST patients (4.5% - 33%). The most common second cancers occurring in this population in percentage terms of the 153 total cancers were:

• Genitourinary Carcinoma-62
High runners included in this total were

o Prostate-28
o Kidney-12

• Gastrointestinal Carcinoma-48
High runners included in this total were

      o Colorectal-17
      o Esophagus-10
      o Pancreas-6

Other major cancers mentioned were:

• Breast-15
• Leukemia/Lymphoma-12
• Head, Neck and Lung-11
• Other sarcomas-9
• Melanoma-9
• Thyroid-6
• Endocrine-3
• Neurologic-1
• Unknown primary-10

These numbers add up to186, reflecting the fact that some patients had multiple additional cancers. Higher percentages of GI carcinoma and lower percentages of prostate cancer were observed in a larger (4,813 GIST patients) and earlier review study.