Lung cancer is categorized is various ways:


The American Joint Committee on Cancer (AJCC) has designated staging by TNM
classification: Primary tumor (T), Regional Lymph Nodes (N), Distant Metastasis (M).


TX: Primary tumor cannot be assessed, or tumor proven by the presence of
malignant cells in sputum or bronchial washings but not visualized by
imaging or bronchoscope or (T0: No evidence of primary tumor)

T1: A tumor that is 3 cm or less in greatest dimension, surrounded by lung
or visceral pleura, and without bronchoscopic evidence of invasion more
proximal than the lobar bronchus (i.e., not in the main bronchus)

T2: A tumor with any of the following features of size or extent:
More than 3 cm in greatest dimension
Involves the main bronchus, 2 cm or more distal to the carina
Invades the visceral pleura associated with atelectasis or obstructive

pneumonitis that extendsto the hilar region but does not involve the entire lung

T3: A tumor of any size that directly invades any of the following: chest
wall (including superior sulcus tumors), diaphragm, mediastinal pleura,
parietal pericardium; or tumor in the main bronchus less than 2 cm
distal to the carina but without involvement of the carina; or
associated atelectasis or obstructive pneumonitis of the entire lung

T4: A tumor of any size that invades any of the following: mediastinum,
heart, great vessels, trachea, esophagus, vertebral body, carina; or
separate tumor nodules in the same lobe; or tumor with a malignant
pleural effusion.


NX: Regional lymph nodes cannot be assessed
N0: No regional lymph node metastasis
N1: Metastasis to ipsilateral peribronchial and/or ipsilateral hilar lymph
nodes, and intrapulmonary nodes including involvement by direct
extension of the primary tumor
N2: Metastasis to ipsilateral mediastinal and/or subcarinal lymph node(s)
N3: Metastasis to contralateral mediastinal, contralateral hilar,
ipsilateral or contralateral scalene, or supraclavicular lymph node(s)


MX: Distant metastasis cannot be assessed
M0: No distant metastasis
M1: Distant metastasis present
Note: M1 includes separate tumor nodule(s) in a different lobe (ipsilateral or


Lung cancer is further categorized by cellular differentiation. Normal tissue is organized, whereas cancerous tissues is more haphazard. We have the following categories, in order of severity:

Well-differentiated, Moderately differentiated, and Poorly differentiated

Lung cancer can also be categorized by where it originates, such as Non-Small Cell Carcinoma, adenocarinoma, squamous cell, and Small-Cell Carcinoma


Patients need to be knowledgeable, since a doctor's time is limited, you want to spend it asking questions about your own or a family members particular condition. To learn about the disease, do the following:

1. Get a good general consumer text about medicine, such as Mayo Clinic medical guide. Read an encyclopedia section on lung cancer.

2. Once you have a basic understanding, go to a medical school and get a specialized text on cancer such as Devita, Cancer Principles and Practice of Oncology. Merck's Manual and Harrison,'s Internal Medicine are also helpful. A specialized text on Lung Cancer is Carney, Lung Cancer.

3. Obtain your relevant medical records, including pathology to acquire a basic understanding of what they say.

4. Then go to Medline,, and get information about recent developments.

5. Go to an internet user group and post a question or make a comment regarding the specifics of your situation.