Can lung cancer spread while waiting?

Perhaps your mum or dad has just been told by their doctor that a scan shows something that could be lung cancer. Or perhaps you had a lung screening scan yourself, and it found a nodule. Either way, you are probably reading this late at night, frightened, and wondering what happens next.

The question I am asked most often in that situation is this: could the cancer spread while we wait for the tests?

I often say that lung cancer doesn't wait, and nor should we.

What does the stage of lung cancer mean?

The stage describes how big the cancer is and how far it has spread. Together with the type of cancer cell, it is the most important thing that decides whether we can aim to cure it. You can read more in my guide, What is lung cancer?

• Stage 1: a small tumour, confined to the lung.
• Stage 2: a larger tumour, or spread to nearby lymph nodes.
• Stage 3: spread to lymph nodes in the centre of the chest, or into nearby structures. Often called locally advanced.
• Stage 4: spread to the other lung, the lining of the lung, or distant organs such as the liver, bones or brain.

The chances of cure fall with each step up. In England, almost 65 out of 100 people diagnosed with stage 1 lung cancer live for at least 5 years. That falls to around 40 out of 100 for stage 2, around 15 out of 100 for stage 3, and around 5 out of 100 for stage 4 [4]. These figures come from Cancer Research UK.

There is good news too. Survival from lung cancer has been improving. Five-year survival in the UK was around 5% for decades, and has risen to around 17% since about 2010 [5]. Better treatments are a big part of that. But those treatments work best when the cancer is caught at an early stage, and that is exactly why the time between diagnosis and treatment matters.

Can lung cancer really change stage in a few weeks?

Yes. Three studies show it clearly. Each one scanned people with lung cancer twice: once at diagnosis, and again just before treatment started.

• One patient, 22 days apart. In a study from Australia, one patient had stage 3 lung cancer on their first PET scan. Twenty-two days later, a second scan showed the cancer had spread to the liver. It was now stage 4 [2].
• 29% lost the chance of curative treatment. In that same study of 28 people waiting a median of 24 days for radiotherapy, 39% had visible growth or spread, and 29% had to switch from treatment aiming to cure to treatment aiming to control [2].
• 32% moved up a stage. A larger study of 181 people at five international centres found that 32% had been upstaged by the time of their planning scan. Their waits ranged from 2 days to about 7 months, with a median of 6 weeks. The researchers also estimated the chance of having moved up a stage by a given day: above 5% by 22 days, 10% by 34 days, and 15% by 42 days [1]. The authors recommend repeating the PET scan if more than three weeks have passed.
• 13% developed distant spread over 8 weeks. A study of 40 people found that 48% showed progression while waiting, and 13% developed new distant spread, moving from curable to incurable [3].

It is in the nature of cancer to grow and spread. These studies simply show how quickly that can happen.

Has my cancer spread while I have been waiting?

If you or your parent has already waited weeks, please do not panic. Sometimes tests take longer than anyone would like. In the largest of these studies, about two-thirds of people did not move up a stage during their wait [1].

Most people do not progress. The aim of moving quickly is to make sure you are not the unlucky one who does. If your scans are more than a few weeks old by the time treatment is being planned, it is reasonable to ask whether they need repeating [1].

Which tests are needed to diagnose and stage lung cancer?

If there is a chance that treatment could aim to cure the cancer, most people need all of these:

1. A CT scan of the chest, liver and adrenal glands [6].
2. A PET-CT scan, which national guidance recommends for everyone who could have curative treatment [6].
3. An MRI scan of the brain. National guidance recommends brain imaging for people with stage 2 or 3 disease before curative treatment [6]. I prefer MRI.
4. A biopsy, to confirm the diagnosis and the type of cancer cell, with enough tissue for molecular testing of the cancer's genes [6].
5. Lung function tests, which guidance recommends for everyone being considered for curative treatment [7].

Your case should then be discussed at a multidisciplinary team meeting, where specialists agree the best treatment together.

Why do lung cancer test results take so long?

The biggest wait is usually for molecular testing. This looks for gene changes in the cancer that can be treated with targeted drugs. The UK Lung Cancer Coalition recommends that results should come back within 14 days of the biopsy, and has called for laboratories to turn samples around within 7 days [8]. In my experience, it often takes 2 to 3 weeks.

That is why I want the biopsy done as early as possible. The genetic clock cannot start until we have tissue. For a stage 1 cancer, we can often go straight to surgery or stereotactic radiotherapy without waiting for molecular results.

Many people tell me the waiting is torture. What they find hardest is being left in the dark: not knowing which tests are needed, which results are back, or what happens next.

How can lung cancer tests be done faster?

The single biggest change is to stop doing tests one at a time.

Too often, a patient has one test, waits for the result, then has the next test, then waits again. The cancer keeps growing in the gaps.

When I first meet a patient, I request all of the tests on that same day, and aim to have them done within a couple of days. I also take blood for circulating tumour DNA testing alongside the biopsy, as a backup in case the tissue sample is not enough.

I also do not think doctors should wait for the multidisciplinary team meeting to decide every next step. Your doctor can arrange the next test while waiting for the meeting. That keeps momentum, and gets you to treatment sooner.

What should I ask my doctor about delays?

If you are supporting a parent, or going through this yourself, these questions are fair to ask:

Can any treatment start while we wait for results?

Sometimes, yes. If the cancer has spread and is causing pain or other symptoms, a short course of radiotherapy can often help without waiting for every result. If a bone-strengthening drug called denosumab may be needed because the cancer has spread to the bones, a dental check should be done before starting it [9]. Getting that done early saves time later.

Fitness matters too. In people having lung cancer surgery, exercise training before the operation roughly halved the risk of lung complications afterwards, and shortened the hospital stay by about two days [10]. Stopping smoking as soon as lung cancer is suspected also lowers the risk of complications after surgery [7].

Is waiting ever the right thing to do?

Yes, sometimes it is.

Lung screening often finds small nodules that are not definitely cancer. For many of these, the right step is a repeat scan after a set interval, as laid out in British Thoracic Society guidelines [11]. If we scan too soon, we may see no change and be falsely reassured. Leaving the right gap lets us see whether a slow-growing nodule is changing, which tells us much more about whether it is cancer.

So waiting is not always the enemy. Unplanned waiting is.

Why this matters to me

I want to give as many people as possible treatment that aims to cure their lung cancer. To do that, I need to see people at the earliest possible stage. What I do not want is for someone with early-stage disease to move to a later stage because of delays in their tests.

If you would like help, I can arrange some or all of the tests, quickly, alongside your NHS care. For some people, that can speed things up. You can find out more about second opinions or how to be referred.

Frequently asked questions

How fast can lung cancer spread?

In one study, a patient's lung cancer moved from stage 3 to stage 4, with new spread to the liver, in 22 days [2]. In a larger study, the risk of moving up a stage passed 10% after about a month of waiting [1].

How long is too long to wait for lung cancer treatment?

There is no single safe limit, but the risk of upstaging rises steadily with time: above 5% by 22 days, 10% by 34 days and 15% by 42 days [1]. If staging scans are more than three weeks old when treatment is planned, the study authors recommend repeating the PET scan [1].

Does everyone's lung cancer spread while they wait?

No. In the largest study, about two-thirds of people did not move up a stage while waiting [1].

Is stage 3 lung cancer curable?

Often, yes, usually with a combination of treatments. Around 15 out of 100 people diagnosed with stage 3 lung cancer in England live for at least 5 years [4].

How long do genetic test results take for lung cancer?

The UK Lung Cancer Coalition recommends results within 14 days of the biopsy [8]. In my experience it often takes 2 to 3 weeks, which is why the biopsy should be done early.

Should a lung nodule be watched or treated straight away?

It depends on its size, appearance and risk. Many nodules found on screening are best checked with a repeat scan after a set interval, following British Thoracic Society guidelines [11].

References

1. Bissonnette J-P, et al. Non-small cell lung cancer stage migration as a function of wait times from diagnostic imaging: a pooled analysis from five international centres. Lung Cancer 2021;155:136–143.
2. Everitt S, et al. High rates of tumor growth and disease progression detected on serial pretreatment fluorodeoxyglucose-positron emission tomography/computed tomography scans in radical radiotherapy candidates with nonsmall cell lung cancer. Cancer 2010;116:5030–5037.
3. Mohammed N, et al. Rapid disease progression with delay in treatment of non-small-cell lung cancer. Int J Radiat Oncol Biol Phys 2011;79:466–472.
4. Cancer Research UK. Survival for lung cancer. Survival by stage, people diagnosed in England 2016 to 2020 (NHS England data). Accessed November 2026.
5. Cancer Research UK. Cancer Statistics Data Hub: survival trends over time, lung cancer. Accessed October 2026.
6. NICE. Lung cancer: diagnosis and management (NG122). Diagnosis and staging, recommendations 1.2.4, 1.2.11, 1.2.14, 1.2.25 and 1.2.26.
7. NICE. Lung cancer: diagnosis and management (NG122). Treatment, recommendations 1.4.1, 1.4.2, 1.5.9 and 1.6.6.
8. UK Lung Cancer Coalition. Faster Testing, Better Outcomes: Genomic Testing in Lung Cancer. March 2025. Reported by ecancer.
9. MHRA. Denosumab: updated recommendations. Drug Safety Update, 2014.
10. Granger C, Cavalheri V. Preoperative exercise training for people with non-small cell lung cancer. Cochrane Database of Systematic Reviews 2022, Issue 9. CD012020.pub3.
11. Callister MEJ, et al. British Thoracic Society guidelines for the investigation and management of pulmonary nodules. Thorax 2015;70 Suppl 2:ii1–ii54.