PET has an established role in the initial staging of patients with newly diagnosed lung and gastrointestinal tumors.PET avidity is described with both maximum and mean standardized uptake values.Malignant cells have increased activity on PET, defined as the standardized uptake value (SUV), with increased uptake of FDG in tumor due to elevated levels of GLUT receptors, elevated intracellular levels of hexokinase and increased rates of glycolysis. However, there is a subset of patients with lung and gastrointestinal tumors that are not PET avid.These patients may present with clinically and systemically aggressive disease with a declining performance status and/or weight loss.

This study will be a retrospective review of patients in the tumor registry with lung and gastrointestinal tumors, not limited to but including small and non-small cell lung cancers, stomach cancer, small intestinal cancer, colon cancer, rectal cancer, liver and intrahepatic bile duct cancers, gallbladder and extrahepatic bile duct cancers, and pancreatic cancer.

There will be a maximum of 10,000 charts/records that will be reviewed to compile the data. Data to be collected will include patients' name, medical record number, date of birth, race, ethnicity, gender, medical history, medications, vital and performance status, vital signs including weight and body mass index, date of cancer diagnosis, clinical and pathologic stage, pathology, treatment course, prior treatment, location of primary lesion, and smoking history. CT and PET findings to be reviewed include the number of involved lymph nodes, size of primary tumor, average/maximum PET avidity in both the primary tumor and involved lymph nodes.

Inclusion Criteria:

Patients with histologically proven lung and gastrointestinal cancers, stages I-IV with PET and/or CT within 6 weeks of diagnosis.

Exclusion Criteria:

There will be no absolute exclusion criteria as long as the inclusion criteria have been met.

Patients with histologically proven lung and gastrointestinal cancers