“What stage is it, and what are my options?” is the first question almost every patient and family asks me after a lung cancer diagnosis. It is also one of the most searched lung cancer questions in Ontario. Here is how I explain it.
First: what type of lung cancer is it?
There are two main types, and they are treated differently.
- Non-small cell lung cancer (NSCLC) makes up about 85% of lung cancers. It includes adenocarcinoma, the most common type, and squamous cell carcinoma. This is the type where surgery plays the biggest role.
- Small cell lung cancer (SCLC) makes up about 15%. It tends to grow and spread quickly, so it is usually treated with chemotherapy and immunotherapy, often with radiation. Surgery is considered only for the rare very early cases.
For non-small cell cancer, the tumour is also tested for biomarkers: gene changes such as EGFR or ALK, and the immune marker PD-L1. These results can open the door to targeted pills or immunotherapy, so they are an important part of planning.
What the stages mean
Lung cancer is staged with the TNM system: the size and extent of the Tumour, whether it has reached the lymph Nodes, and whether it has Metastasized (spread) elsewhere in the body. Staging uses a CT scan, a PET scan, often a brain MRI, and in many cases a biopsy of the lymph nodes in the chest, for example by EBUS (a camera test through the airway).
| Stage | What it usually means | Main treatment (non-small cell) |
|---|---|---|
| Stage I | A small tumour confined to the lung, with no lymph node spread | Surgery. Focused radiation (SBRT) if surgery isn’t safe |
| Stage II | A larger tumour, or spread to lymph nodes within the lung | Surgery, usually with chemotherapy, immunotherapy or targeted drugs before or after |
| Stage III | Spread to lymph nodes in the centre of the chest, or a tumour invading nearby structures | A team plan: chemo-radiation then immunotherapy for most; surgery for selected patients |
| Stage IV | Spread to the other lung, the lining of the lung, or distant organs | Medication: targeted therapy, immunotherapy and/or chemotherapy; radiation for symptoms |
Stage I and II: where surgery offers the best chance of cure
For early-stage non-small cell lung cancer, surgery to remove the tumour along with the surrounding lymph nodes offers the best chance of cure. In the international staging data, about 92% of people with the smallest stage I cancers are alive five years later, compared with about 60% at stage IIA and 36% at stage IIIA.1 The earlier it is found, the better the outlook.
The operation is usually a lobectomy, which removes the lobe of the lung containing the tumour. For some small, early tumours, a segmentectomy, which removes a smaller section of the lobe, is now an option that preserves more lung. A large trial found survival with segmentectomy at least as good as with lobectomy for carefully selected small tumours.2
I perform these operations with minimally invasive techniques, either VATS (video-assisted keyhole surgery) or robotic surgery, through a few small incisions rather than a large opening of the chest. That usually means less pain, a shorter hospital stay and a faster return to normal life. You can read about what to expect in the recovery guide for lung surgery.
Treatment around surgery has also improved a great deal. For some stage II and III cancers, chemotherapy combined with immunotherapy before surgery increases the chance that no living cancer is left when the tumour is removed.3 For cancers with an EGFR mutation, a targeted pill taken after surgery substantially reduces the risk of the cancer coming back.4
Stage III: a team decision
Stage III lung cancer is the most varied stage, and it is where a multidisciplinary team (thoracic surgeon, medical oncologist and radiation oncologist) matters most. For many patients, the standard is chemotherapy and radiation together, followed by a year of immunotherapy, which improves survival.5 For selected patients, particularly with limited lymph node spread, treatment before surgery followed by an operation is the better path.
Stage IV: treatment with medication
When lung cancer has spread to distant parts of the body, surgery to remove the lung tumour usually doesn’t help, and treatment is based on medication. This is where biomarker testing makes the biggest difference: many people with EGFR, ALK or other gene changes can take targeted pills, and others benefit from immunotherapy. Radiation is used to control specific symptoms. Stage IV lung cancer is generally not curable, but these treatments have extended survival and quality of life considerably.
Why early detection changes everything
Earlier in my career, most patients I saw with lung cancer had advanced disease by the time it was found. Too often, it had already spread too far for an operation to be an option, and I couldn’t offer surgery at all. Lung cancer screening is changing that. Finding cancers at stage I or II means I can operate early, when the chance of cure is highest. If you are 55 to 74 and have smoked, ask your family doctor about the Ontario Lung Screening Program.
Learn more about what causes lung cancer, or see the lung cancer surgery page.
Common questions
What is the best treatment for early-stage lung cancer?
What is the difference between small cell and non-small cell lung cancer?
What is the survival rate for stage 1 lung cancer?
Can stage 4 lung cancer be treated?
Is lung cancer surgery done by keyhole?
References
- Goldstraw P, Chansky K, Crowley J, et al. 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. J Thorac Oncol. 2016;11(1):39–51.
- Saji H, Okada M, Tsuboi M, et al. Segmentectomy versus lobectomy in small-sized peripheral non-small-cell lung cancer (JCOG0802/WJOG4607L): a multicentre, open-label, phase 3, randomised, controlled, non-inferiority trial. Lancet. 2022;399(10335):1607–1617.
- Forde PM, Spicer J, Lu S, et al. Neoadjuvant nivolumab plus chemotherapy in resectable lung cancer. N Engl J Med. 2022;386(21):1973–1985.
- Wu YL, Tsuboi M, He J, et al. Osimertinib in resected EGFR-mutated non-small-cell lung cancer. N Engl J Med. 2020;383(18):1711–1723.
- Antonia SJ, Villegas A, Daniel D, et al. Durvalumab after chemoradiotherapy in stage III non-small-cell lung cancer. N Engl J Med. 2017;377(20):1919–1929.