Lung Cancer

“There are two main forms of lung cancer – small cell lung cancer and non-small cell lung cancer.

There are several types of non-small cell lung cancer characterized by different kinds of cancer cells. The cancer cells of each type grow and spread in different ways. The most common types of non-small cell lung cancer are squamous cell carcinoma that begins in the thin, flat squamous cells; large cell carcinoma; and adenocarcinoma, which begins in the cells that line the alveoli. Other less common types of non-small cell lung cancer are: pleomorphic, carcinoid tumor, salivary gland carcinoma, and unclassified carcinoma.

According to the National Cancer Institute, approximately 238,340 patients will be diagnosed with lung and bronchus cancer in the United States in 2023, and about 129,070 people will die of the disease. The five-year survival rate for these cancers is 25.4 percent.

Smoking cigarettes, pipes, or cigars is the most common cause of lung cancer. Other risk factors for lung cancer include being exposed to secondhand smoke, having a family history of lung cancer, being treated with radiation therapy to the breast or chest, exposure to asbestos, chromium, nickel, arsenic, soot, or tar in the workplace, and exposure to radon. When smoking is combined with other risk factors, the risk of lung cancer is increased.”


FDG PET/CT (Lung Cancer) Visualized at two time points

FDG PET CT images of a non-small-cell right lung cancer, which was biopsy proven showing a favorable but partial response to chemotherapy. The biopsy proven right lung squamous cell carcinoma is much reduced in size with 85% decreased metabolic activity in comparison to the baseline study (bottom panel). The FDG-avid left upper lung nodules (circled) are essentially resolved as well.

NCCN’s Commentary on PET/CT application in Lung Cancer Management

“A positive PET result is defined as a standardized uptake value (SUV) in the lung nodule greater than the baseline mediastinal blood pool. A positive PET scan finding can be caused by infection or inflammation, including absence of lung cancer with localized infection, presence of lung cancer with associated (eg, postobstructive) infection, and presence of lung cancer with related inflammation (eg, nodal, parenchymal, pleural). (page DIAG-2)

Concomitant staging is beneficial because it avoids additional biopsies or procedures. It is preferable to biopsy the pathology that would confer the highest stage (ie, to biopsy a suspected metastasis or mediastinal lymph node rather than the pulmonary lesion). Therefore, PET/CT imaging is frequently best performed before a diagnostic biopsy site is chosen in cases of high clinical suspicion for aggressive, advanced-stage tumors. (page DIAG-A)

A false-negative PET scan can be caused by a small nodule, low cellular density (nonsolid nodule or ground-glass opacity [GGO]), or low tumor avidity for FDG (eg, adenocarcinoma in situ [previously known as bronchoalveolar carcinoma], carcinoid tumor). (page DIAG-3)

FDG PET/CT is currently not warranted in the routine surveillance and follow-up of patients with NSCLC. However, many benign conditions (such as atelectasis, consolidation, and radiation fibrosis) are difficult to differentiate from neoplasm on standard CT imaging, and FDG PET/CT can be used to differentiate true malignancy in these settings. However, if FDG PET/CT is to be used as a problem-solving tool in patients after radiation therapy, histopathologic confirmation of recurrent disease is needed because areas previously treated with radiation therapy can remain FDG avid for up to 2 years.” (page NSCL-16).

Permission Pending from the NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines®) for Non-Small Cell Lung Cancer Version 3.2023 — April 13, 2023. © National Comprehensive Cancer Network, Inc. 2023. All rights reserved. Accessed August 15, 2023 To view the most recent and complete version of the guideline, go online to