Lung Cancer

Question 1

Which histological subtype of lung cancer has the most favourable prognosis

Answer 1

Carcinoid - <5% lung tumours, typically cured by surgery

Question 2

PET scans:

Answer 2

Injecting a radioisotope bound to an analog of D-glucose (FDG) into the patient. – Cells with increased activity (ie: NSCLC) will accumulate more FDG because glycolysis is upregulated. – When the patient is imaged, two photos emitted by the FDG are detected.
PET scan is most useful in these three clinical settings:
1) Solitary pulmonary nodules – distinguishes benign vs malignant. – sens 96%, spec 78%.
2) Carcinoma staging
3) Surveillance – has great sensitivity and specificity for detecting recurrence or persistent malignant disease from changes caused by radiation or surgery. Not useful when lesion is <1cm

Note:
Hyperglycemia can reduce intracellular uptake of the radioactive substrate FDG
False negative results can occur with carcinoid tumors