Is Stage 1 lung cancer curable?

Yes, Stage 1 lung cancer is often curable. When the tumour is completely removed by surgery, five-year survival rates range from roughly 68% to over 90% depending on the sub-stage, outcomes that make early detection the most important single factor.

Does Stage 1 lung cancer always need surgery?

Surgery is the first choice, but it is not always possible. Patients with poor lung function or significant other health conditions can be effectively treated with SBRT, which achieves comparable local control for many Stage 1 tumours.

Can Stage 1 lung cancer recur after surgery?

Yes, recurrence is possible even after complete resection. Five-year recurrence-free survival is around 81 to 82% for Stage 1 NSCLC. Regular CT scans every six months for two years, then annually, are recommended after treatment.

What is the difference between Stage 1A and Stage 1B?

Stage 1A tumours are 3 cm or smaller with no structural involvement. Stage 1B tumours are 3 to 4 cm or have specific features such as visceral pleural involvement, but still have no lymph node spread.

Why is Stage 1 lung cancer often found without symptoms?

Small tumours confined to lung tissue rarely press on airways or nerves. Symptoms typically emerge once the tumour grows or spreads, which is why annual LDCT screening is recommended for high-risk individuals aged 50 to 80 with a heavy smoking history.

Stage 1 Lung Cancer: Symptoms, Treatment, and Survival Rate

What Is Stage 1 Lung Cancer?

Stage 1 applies almost exclusively to non-small cell lung cancer (NSCLC), which accounts for about 85% of all lung cancer cases. At this stage, the primary tumour sits within lung tissue and has not invaded nearby lymph nodes (N0) or spread to distant organs (M0).

Staging follows the AJCC TNM system, version 9, in use since January 2025. Stage 1 covers T1 and some T2 tumours with N0M0 status. It is split into two main groups, Stage 1A and Stage 1B.

Stage 1A - Sub-stages 1A1, 1A2, and 1A3

All Stage 1A tumours are 3 cm or smaller, confined to lung tissue or the visceral pleura, and have not reached the main bronchus or any lymph nodes.

Stage 1A has three sub-stages:

Stage 1A1: Tumour is 1 cm or smaller. Also includes minimally invasive adenocarcinoma, a tumour with a small invasive component of 5 mm or less.
Stage 1A2: Tumour is between 1 cm and 2 cm, with no bronchial, pleural, or lymph node involvement.
Stage 1A3: Tumour is between 2 cm and 3 cm, with no lymph node or pleural involvement.

Stage 1B

Stage 1B tumours are between 3 cm and 4 cm. Smaller tumours may also be Stage 1B if they meet at least one of the following:

The tumour involves the main bronchus but is not within 2 cm of the carina.
The tumour has grown into the visceral pleura.
The tumour has caused partial lung collapse or obstructive pneumonitis extending to the hilar region.

Lymph node involvement is absent in all Stage 1B cases.

Symptoms of Stage 1 Lung Cancer

Stage 1 lung cancer often causes no symptoms at all. The tumour is small and not yet pressing on major airways or surrounding structures. This is why most Stage 1 cases are found incidentally, through LDCT screening or imaging done for an unrelated condition.

When symptoms do occur, they are often mistaken for a respiratory infection, acid reflux, or smoking-related changes. Common symptoms include:

A cough that lasts longer than three weeks or that gets worse over time
Coughing up blood or blood-streaked mucus (haemoptysis)
Shortness of breath, particularly on exertion
Pain or discomfort in the chest with deep inhaling or coughing
Hoarseness or a change in voice
Recurring chest infections like bronchitis or pneumonia
Unexplained fatigue or loss of energy
Mild, unexplained weight loss or reduced appetite

None of these symptoms is unique to lung cancer. However, any symptom lasting more than two to three weeks, especially in a current or former smoker, warrants medical evaluation. Even Stage 1 cancer found because of symptoms carries a better outlook than cancer found at a later stage.

How Is Stage 1 Lung Cancer Diagnosed?

Imaging

A chest X-ray is frequently the first step in the diagnosis process. In order to obtain a sharper picture, doctors typically follow up with a low-dose CT scan or a contrast CT if something strange appears. LDCT can detect tumours far smaller than those visible on a standard X-ray, which is why it is the recommended screening tool for high-risk individuals aged 50 to 80 with a significant smoking history.

A PET-CT scan may be ordered to assess whether the lesion is metabolically active and to check for any evidence of lymph node or distant spread.

Biopsy

To confirm the diagnosis, doctors need a sample of the tumour. This can be done through bronchoscopy, where a thin camera is passed into the airways, a CT-guided needle biopsy through the chest wall, or sometimes a surgical biopsy if the tumour is harder to reach. The same sample is also tested for gene changes such as EGFR, ALK, ROS1, and KRAS, which helps guide treatment, especially if surgery is not an option or if the cancer comes back.

Treatment for Stage 1 Lung Cancer

Surgery

Surgery is the standard treatment for Stage 1 NSCLC in patients fit enough to undergo an operation. The goal is complete removal with clear margins.

Lobectomy: Surgical removal of the entire lobe containing the tumour. This has been the historical gold standard for Stage 1 lung cancer.
Segmentectomy: Removal of the lung segment containing the tumour, preserving more lung tissue. For tumours 2 cm or smaller (Stage 1A1-1A2), landmark trials (JCOG0802 and CALGB 140503) showed segmentectomy provides equivalent survival to lobectomy while protecting lung function.
Wedge Resection: Removal of a small wedge of lung tissue around the tumour. Used in patients with limited lung reserve who cannot tolerate a larger resection.

Most thoracic surgeons now perform these procedures using video-assisted thoracoscopic surgery (VATS) or robotic-assisted techniques, which involve small incisions and result in shorter hospital stays and faster recovery.

Stereotactic Body Radiotherapy (SBRT)

For people who are not able to have surgery, whether due to poor lung function, heart problems, or personal choice, SBRT can be a good option. It uses focused, high-dose radiation given over a few sessions to target the tumour. In many Stage 1 cases, it controls the cancer as effectively as surgery and is widely used as an alternative.

Adjuvant Therapy After Surgery

Stage 1A patients are generally monitored after surgery without further treatment. For Stage 1B, adjuvant therapy may be recommended in specific situations:

Adjuvant osimertinib (targeted therapy) is approved for Stage 1B patients whose tumours carry an EGFR mutation following complete resection.
Adjuvant atezolizumab (immunotherapy) is approved for Stage 1B patients with PD-L1 expression of 1% or more.
Adjuvant chemotherapy may be considered for Stage 1B with high-risk pathological features such as visceral pleural invasion or lymphovascular invasion.

Stage 1 Lung Cancer Survival Rate

Stage 1 carries the best survival outlook of all lung cancer stages. Survival decreases incrementally as the tumour grows, which is why sub-stage matters.

Five-year survival rates by sub-stage, based on a 16-country IASLC analysis:

Stage 1A1: approximately 90 to 92%
Stage 1A2: approximately 83 to 85%
Stage 1A3: approximately 77 to 80%
Stage 1B: approximately 68 to 73%

In patients with adenocarcinoma who have complete tumour removal, five-year survival in Stage 1A1 has been reported as high as 95 to 100% in specialist centres (PMID 36260144). For Stage 1 NSCLC overall, about 81 to 82% of patients remain cancer-free at five years, based on a 2023 systematic review published in CHEST.

These numbers are based on patients treated in earlier years. With newer options like minimally invasive surgery, SBRT, and adjuvant targeted therapies now available, outcomes for people diagnosed today may be even better.

Conclusion

Stage 1 lung cancer is the earliest stage, where the tumour remains confined to the lung without lymph node spread. Early detection allows treatment with surgery or targeted radiotherapy in many cases. With timely care, patients often have a strong chance of long-term survival. To know more on lung cancer contact our lung cancer.