Stage 1

The stage of a cancer tells you how big it is and whether it has spread. It helps your doctor decide which treatment you need. It can also give some idea of your outlook (prognosis).

Stage 1 is part of the number staging system and means your cancer is small. It hasn’t spread to your lymph nodes or other distant organs.

Stage 1 can be divided into 1A and 1B.

Here is a simplified description:

Stage 1A means the cancer is 3cm or smaller. 

Stage 1B means the cancer is between 3cm and 4cm.

It might also be growing into structures such as:

  • the main airway of the lung (main bronchus)
  • the membrane covering the lung (visceral pleura)
Diagram showing stage 1A and 1B lung cancer

Or the cancer is making the lung partly or completely collapse by blocking the airway.

TNM stages

The TNM staging system stands for Tumour, Node, Metastasis.

  • T describes the size of the tumour
  • N describes whether there are any cancer cells in the lymph nodes
  • M describes whether the cancer has spread to a different part of the body

In the TNM staging system, stage 1A is the same as T1a-c, N0, M0.

Stage 1B is the same as T2a, N0, M0


The stage of your cancer helps your doctor to decide which treatment you need. Treatment also depends on:

  • your type of cancer (the type of cells the cancer started in)
  • where the cancer is
  • other health conditions that you have

The treatment for small cell lung cancer is different to the treatment for non small cell lung cancer.

Non small cell lung cancer

If you have surgery

If you are fit enough, you usually have surgery to remove

  • part of your lung (a lobectomy, segmentectomy or wedge resection)
  • all of the lung (pneumonectomy)

Your fitness for surgery depends on your general health and how well you are likely to recover.

After surgery your doctor might offer you chemotherapy. This lowers the chance of your cancer coming back. It is called adjuvant chemotherapy.

If your surgeon is not able to remove all of your tumour, you might have radiotherapy after surgery.

If you aren’t having surgery

If you aren’t fit enough for surgery or you decide that you don't want to have it, you might have:

  • radiotherapy - either traditional radiotherapy or stereotactic ablative body radiotherapy
  • radiofrequency ablation (RFA)

Small cell lung cancer

Chemotherapy followed by radiotherapy to the chest is the main treatment for small cell lung cancer. 

If you are fit enough you might have chemoradiotherapy. This means you have chemotherapy at the same time as radiotherapy.

Some people have surgery to remove all or part of the lung but this is very rare in small cell lung cancer. It is not usually possible to remove all of the cancer with surgery. After surgery, you have chemotherapy and possibly radiotherapy.

After you finish treatment, you might have radiotherapy to your head. This treatment is called prophylactic cranial radiotherapy (PCR). You have this because it is quite common for small cell lung cancer to spread to the brain. The radiotherapy aims to kill any cancer cells that may have already spread to the brain but are still too small to see on scans.

You might have prophylactic cranial radiotherapy if:

  • your chemotherapy or radiotherapy treatment has stopped your cancer growing
  • you are well enough

Other stages

Last reviewed: 
29 Jan 2020
  • TNM Classification of Malignant Tumours (8th edition)
    International Union Against Cancer   
    John Wiley and Sons, 2016

  • AJCC Cancer Staging Manual (8th edition)
    American Joint Committee on Cancer
    Springer, 2016

  • Lung cancer: diagnosis and management
    National Institute for Health and Care Excellence (NICE), 2019

  • Management of lung cancer
    Scottish Intercollegiate Guideline Network, 2014

  • The IASLC Lung Cancer Staging Project: Proposals for Revision of the TNM Stage Groupings in the Forthcoming (Eighth) Edition of the TNM Classification for Lung Cancer
    P Goldstraw and others for the Study of Lung Cancer Staging and Prognostic Factors Committee
    Journal of Thoracic Oncology, 2015. Volume 11, Number 1

  • Guidelines on the Radical Management of Patients with Lung Cancer
    British Thoracic Society guidelines
    Thorax, October 2010. Volume 65, Supplement 3

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