Stage 3 Lung Cancer
Locally Advanced NSCLC: Treatment in London

Why This Page Exists

The first question in stage 3 lung cancer is whether surgery is on your treatment plan. The drug regimen follows from that answer.

For most patients diagnosed today the answer is yes, including many whose disease would have been called inoperable five years ago. The route to that answer, and what follows it, has changed since 2022. This page sets out the stage 3 (stage III, locally advanced) lung cancer pathway as it stands in 2026, starting with the decision about surgery and then the treatments that follow it.

Aspect	Resectable Stage 3 Pathway	Unresectable Stage 3 Pathway
Common name	Perioperative chemoimmunotherapy	The PACIFIC pathway
Treatment sequence	Chemotherapy + immunotherapy → Surgery → Immunotherapy (up to 1 year)	Chemotherapy + radiotherapy together → Immunotherapy (up to 1 year)
Goal	Cure through removal of all visible and microscopic cancer	Cure through chemoradiation, with consolidation immunotherapy reducing the risk of recurrence
Evidence base	Six positive phase 3 trials since 2022: CheckMate 816, KEYNOTE-671, AEGEAN, CheckMate 77T, Neotorch, RATIONALE-315	PACIFIC trial (Antonia, NEJM 2017); LAURA trial (Lu, NEJM 2024) for EGFR-mutated patients
Approximate duration	4–5 months before surgery; up to 1 year of immunotherapy afterwards	6–7 weeks of chemoradiotherapy; up to 1 year of consolidation immunotherapy
Who decides this is for you	Thoracic MDT, based on tumour pattern, lymph node involvement, lung function, and fitness for surgery	The same MDT, based on extensive lymph node spread, tumour location making safe resection impossible, or significant comorbidities ruling out surgery

An important clarification

Both pathways are standard treatments, for different patients. Some medical summaries, including AI-generated ones, describe chemoradiotherapy followed by immunotherapy as the "gold standard" for all stage 3 lung cancer.

That is true for unresectable disease. For resectable disease, the standard is the perioperative pathway, supported by six phase 3 trials, and the criteria for "resectable" have widened since 2022.

Treatment therefore depends on which pathway fits the disease, and that decision needs a thoracic surgical opinion alongside oncology input.

Whether stage 3 lung cancer is "resectable" is judged on four factors, weighed together by the multidisciplinary team:

Factors 1 and 2 describe the cancer. Factors 3 and 4 describe the patient and the operation they can withstand.

What Has Changed Since 2022

Five years ago, the line between resectable and unresectable was drawn relatively tightly. Patients with T4 tumours (invading major structures), bulky or multistation N2 disease, or borderline lung function were often routed to chemoradiotherapy without surgery being seriously considered.

Three things have changed in clinical practice since then:

1. Chemoimmunotherapy can shrink tumours considerably before surgery, converting cancers that looked unresectable on the diagnostic scan into ones that are operable after restaging.
2. The robotic platform handles fibrosis better. Chemoimmunotherapy causes scarring around the tumour and lymph nodes; the magnification, stability, and articulated instruments of the robotic platform make dissection through this scarring significantly more feasible than with older keyhole techniques.
3. The trial evidence extends into stage IIIB. The perioperative phase 3 trials enrolled patients with T4 disease and resectable stage IIIB disease, and the survival benefit applies to these groups as well as to stage IIIA.

The practical result: patients with T4N1 disease, T4N2 disease, and multistation N2 disease who would once have been told surgery was "off the table" are now increasingly considered for the surgical pathway after induction chemoimmunotherapy. The decision is made case by case, and it can change after restaging.

In the perioperative trials that report it, between 17% and 41% of patients had a complete pathological response, against 2% to 6% with chemotherapy alone (trial table below). How many patients reach this pathway depends on how resectability is judged at the start. For anyone newly diagnosed with stage 3 lung cancer, and particularly anyone told their disease is "borderline" or "probably not operable", a second opinion at an experienced centre before the treatment plan is finalised is reasonable. The reasons people are given, and which of them can change, are set out on the page for patients told surgery is not an option.

Trial	Immunotherapy	Design	N	Headline result	What it means for surgery
CheckMate 816 Forde et al. NEJM 2022 · 5-yr OS ASCO 2025	Nivolumab	Neoadjuvant only (3 cycles)	358	5-year OS 65% vs 55%; pCR 24% vs 2.2%	Established that immunotherapy before surgery does not delay or compromise the operation.
KEYNOTE-671 Wakelee et al. NEJM 2023 · 5-yr ESMO 2025	Pembrolizumab	Perioperative (4 cycles pre-op + 13 cycles post-op)	797	5-year OS 64.6% vs 53.6%; 5-year EFS 49.9% vs 26.5%	Largest of the six trials. Survival benefit holds at five years, in both node-positive and node-negative groups.
AEGEAN Heymach et al. NEJM 2023	Durvalumab	Perioperative (4 cycles pre-op + 12 months post-op)	802	32% reduction in risk of recurrence, progression or death; pCR 17.2% vs 4.3%	Confirmed the perioperative signal with a different immunotherapy drug; ~70% of trial population had stage 3 disease.
CheckMate 77T Cascone et al. NEJM 2024 · N2 update Nature Cancer 2026	Nivolumab	Perioperative (4 cycles pre-op + 13 cycles post-op)	461	EFS HR 0.58 overall; pCR 25.3% vs 4.7%	Pneumonectomy rate 1% vs 14% in the N2 subgroup, the largest reduction in pneumonectomy reported in these trials. Detail below.
Neotorch Lu et al. JAMA 2024	Toripalimab	Perioperative (3 cycles pre-op + 1 cycle post-op + 13 cycles maintenance)	404 (stage III)	EFS HR 0.40; MPR 48.5% vs 8.4%	Pure stage IIIA/IIIB population; consistent with the global trials.
RATIONALE-315 Yue et al. Lancet Respir Med 2025	Tislelizumab	Perioperative (3–4 cycles pre-op + 8 cycles post-op)	453	EFS HR 0.56; pCR 40.7% vs 5.7%	A sixth positive trial. The open questions concern sequencing: how many cycles before surgery, and how long immunotherapy continues afterwards.

N2 disease means the cancer has reached lymph nodes in the centre of the chest, between the lungs, on the same side as the original tumour. It is the most debated category in stage 3 lung cancer, because the decision to operate or not carries the largest consequences either way.

Until recently, N2 disease was often treated with chemoradiotherapy rather than surgery, particularly when it involved multiple lymph node stations or when the nodes were enlarged ("bulky"). Surgery in this setting frequently meant removal of the whole lung (pneumonectomy), with significant impact on lung function for life.

The most informative data on what perioperative immunotherapy has changed in N2 disease comes from CheckMate 77T, with supporting evidence from AEGEAN and KEYNOTE-671. All three trials have published subgroup analyses focused specifically on patients with N2 involvement.

N2 Subgroup Outcomes: Perioperative Immunotherapy vs Placebo

Outcome (N2 patients)	CheckMate 77T	AEGEAN	KEYNOTE-671
Event-free survival benefit	HR 0.46 (54% reduction in risk)	HR 0.63 (37% reduction)	Favourable trend in node-positive subgroup
Complete pathological response (pCR)	22% vs 5.6%	16.6% vs 4.9%	Not separately reported in N2 subgroup
Lymph nodes cleared by treatment (downstaging to ypN0)	57% vs 44%	47% vs 40%	Not separately reported in N2 subgroup
Pneumonectomy rate	1% vs 14%	9.2% vs 11.1%	Not separately reported in N2 subgroup

Three findings stand out for any patient told they have N2 disease.

1. Cancer is cleared from lymph nodes in roughly half of patients. In the CheckMate 77T N2 subgroup, 57% of patients had no remaining cancer in their mediastinal nodes at the time of surgery. Nodal clearance is the main contributor to the survival benefit.
2. Whole-lung removal becomes uncommon. Pneumonectomy rate in the N2 subgroup fell from 14% to 1% in CheckMate 77T. The treatment shrinks central tumours enough that a lobectomy, which preserves most of the lung, becomes possible where it was not before.
3. The benefit holds in multistation N2. Patients with cancer in multiple separate lymph node stations, the N2 subtype with the poorest outlook, also had an event-free survival benefit with perioperative immunotherapy (57% reduction in event risk in CheckMate 77T; favourable trend in AEGEAN).

Were the lymph nodes biopsied, or only seen on a scan?

A PET-CT scan shows lymph nodes that are active. That activity is often cancer, and it can also be inflammation or old infection. Some patients are given stage 3 on lymph nodes that were seen on a scan and never sampled. The multidisciplinary team asks for the nodes to be sampled before the stage is settled, because the result decides between surgery and chemoradiotherapy. The first test is usually an EBUS, a camera passed into the airway under sedation that takes needle samples from the nodes. Where EBUS is not possible or not tolerated, the nodes can be removed by mediastinoscopy, a day-case operation under general anaesthetic, or colleagues can perform the EBUS under general anaesthetic.

A lymph node above the collarbone (a supraclavicular node) is counted as N3, which places the cancer in stage 3. On its own it does not make the cancer stage 4. In tumours at the very top of the lung (superior sulcus or Pancoast tumours), a supraclavicular node on the same side is often treated as part of the region around the tumour, and whether surgery is part of the plan is decided case by case at the multidisciplinary meeting.

N2 disease is the subgroup where a second opinion at a thoracic surgical centre changes things most often. If you have been told you have N2 lung cancer and chemoradiotherapy is the only pathway being discussed, ask whether your case has been reviewed by a thoracic surgeon as well as by an oncologist.

The Question to Ask Before Treatment Starts

Has my tumour been tested for EGFR mutation, ALK rearrangement, and PD-L1 expression?

If the answer is no or "not yet", systemic treatment should not start until results are available. Testing typically takes one to two weeks and changes the treatment plan in about a quarter of stage 3 patients. Patients sometimes find themselves several cycles into chemoimmunotherapy before discovering their tumour carried a targetable mutation that would have led to a different, more effective pathway.

Reference	Treatment	Who it is for	Based on
NICE TA876 March 2023	Neoadjuvant nivolumab with chemotherapy	Resectable NSCLC, 4 cm or larger or with involved lymph nodes, before surgery only	CheckMate 816
NICE TA1017 November 2024	Perioperative pembrolizumab	Resectable NSCLC with high risk of recurrence, given before surgery and continued for up to one year afterwards	KEYNOTE-671
NICE TA1127 February 2026	Perioperative nivolumab	Resectable NSCLC with high risk of recurrence, an alternative to perioperative pembrolizumab	CheckMate 77T
NICE TA1037 February 2025	Adjuvant osimertinib	EGFR-mutated NSCLC after complete surgical resection; three years of tablets after surgery	ADAURA
NICE TA1010 January 2025	Osimertinib after chemoradiotherapy	EGFR-mutated unresectable stage 3 NSCLC, after concurrent chemoradiotherapy	LAURA
NICE TA1071 June 2025	Adjuvant atezolizumab	PD-L1 positive NSCLC after surgery and adjuvant chemotherapy	IMpower010
NICE TA823 August 2022	Consolidation durvalumab	Unresectable stage 3 NSCLC, after concurrent chemoradiotherapy (the PACIFIC pathway)	PACIFIC
NICE NG122 Last update 2024	Lung cancer: diagnosis and management guideline	The national framework requiring MDT review, biomarker testing, and multi-modality treatment planning for every resectable lung cancer	Guideline

The decisions on staging, biomarker testing, the choice between the two pathways, and the sequencing of treatments require input from multiple specialists reviewing the same case together. National guidance (NICE NG122) requires this for every patient with resectable lung cancer in the UK. The forum where it happens is the lung cancer multidisciplinary team meeting, the MDT.

Dr Okiror is part of the lung cancer MDT at London Bridge Hospital, attending regularly as one of the thoracic surgeons in the meeting. Every private patient under his care is discussed at this MDT before a treatment plan is finalised.

The team brings together six specialties:

Each case is reviewed collectively. Imaging is displayed on the screen. The pathologist confirms tumour type and biomarker status. The thoracic surgeon assesses resectability. The oncologists discuss systemic options. A plan is agreed before anyone speaks to the patient.

Published experience. Dr Okiror co-authored the 2025 Guy's Cancer Centre real-world series on neoadjuvant chemoimmunotherapy in operable lung cancer. Toki M, Elkhalifa M, Bille A, Tan C, Ashrafian L, Okiror L, et al. Lung Cancer 2025;200(Suppl 1):108200. doi: 10.1016/j.lungcan.2025.108200.

Surgery after three or four cycles of chemoimmunotherapy is more technically demanding than surgery on an untreated tumour. The tissues develop fibrosis, a form of scarring. The natural anatomical planes between structures that normally make keyhole surgery feasible can become obliterated.

Many centres respond to this difficulty by converting the operation to open thoracotomy, a larger incision that requires the ribs to be spread apart, a longer hospital stay, and slower recovery.

Patients who have just completed four months of systemic therapy are the least able to tolerate a large open operation. The robotic approach, where it remains feasible, shortens their hospital stay and returns them to daily life sooner.

Most of Dr Okiror's private patients having surgery after chemoimmunotherapy at London Bridge Hospital have keyhole robotic surgery. A minority require conversion to open thoracotomy during the operation if the anatomy is too distorted to continue safely. That decision is made in the interests of safe and complete cancer clearance.

For a walk-through of the surgical journey week by week, from the first scan to discharge home, see the patient guide on surgery after chemotherapy and immunotherapy.

Dr Okiror consults and operates at both London Bridge Hospital and The Lister Hospital Chelsea.

For straightforward lung cancer surgery, either hospital offers full robotic capability and excellent private care.

For more complex cases, for instance surgery forming part of multi-modality treatment for stage 3 disease, Dr Okiror usually recommends London Bridge Hospital, which has more experience and fuller support for these operations.

Patients first seen at The Lister who are found to have more complex disease are not turned away. The surgical episode transfers to LBH, while consultations and follow-up can continue at whichever hospital is more convenient for the patient.

What is stage 3 lung cancer?

Stage 3 lung cancer (also written stage III) is locally advanced non-small cell lung cancer. The cancer has grown beyond the lung itself but has not spread to distant organs such as the liver, brain, or bones. It is divided into three substages, stage IIIA, stage IIIB and stage IIIC, based on how far the tumour has grown and which lymph nodes are involved. Curative-intent treatment remains possible for the great majority of patients with stage 3 disease.

Is stage 3 lung cancer curable?

Yes. Stage 3 lung cancer is treated with curative intent in most patients. The cure depends on the substage, biomarker testing results, lung function, fitness, and whether the cancer can be surgically removed. The modern combined approach of chemotherapy with immunotherapy before surgery, with further immunotherapy afterwards, has substantially improved survival over the past four years across six large international trials. For patients whose disease cannot be surgically removed, chemoradiotherapy followed by consolidation immunotherapy is also a curative pathway.

What is the gold standard treatment for stage 3 lung cancer?

There is no single gold standard for all stage 3 lung cancer. There are two pathways, and which one is right depends on whether the cancer is surgically removable. For resectable stage 3 disease, the modern standard is chemotherapy combined with immunotherapy before surgery (perioperative chemoimmunotherapy), supported by six positive phase 3 trials since 2022. For unresectable stage 3 disease, the standard is chemoradiotherapy followed by up to one year of consolidation durvalumab, known as the PACIFIC pathway. For EGFR-mutated unresectable disease, osimertinib after chemoradiotherapy is now the standard. The first decision is therefore whether the cancer is resectable, made by a thoracic multidisciplinary team.

What is the difference between stage IIIA, IIIB, and IIIC lung cancer?

Stage IIIA includes tumours with limited nearby lymph node involvement, or smaller tumours with mediastinal lymph nodes on the same side as the tumour (N2 disease). Surgery is usually possible after chemoimmunotherapy. Stage IIIB describes larger or more invasive tumours (T4) with significant lymph node involvement; surgery is sometimes possible after the MDT reviews the response to treatment. Stage IIIC describes cancer that has spread to lymph nodes on the opposite side of the chest or above the collarbone; surgery is uncommon in IIIC, and chemoradiotherapy with consolidation immunotherapy is usually the route.

What is neoadjuvant chemoimmunotherapy?

Neoadjuvant chemoimmunotherapy is platinum-based chemotherapy combined with immunotherapy given before surgery, usually for three or four cycles over nine to twelve weeks. It shrinks the tumour, treats microscopic cancer cells already spread beyond the lung, and helps the body mount a lasting immune response. Surgery is planned four to eight weeks after the final cycle. After surgery, immunotherapy is sometimes continued for up to one year. This combined approach is called perioperative chemoimmunotherapy and is supported by the KEYNOTE-671, AEGEAN, CheckMate 77T, Neotorch, and RATIONALE-315 phase 3 trials.

What tests should be done before stage 3 lung cancer treatment starts?

Three tests on the tumour tissue are essential before systemic treatment for stage 3 lung cancer: EGFR mutation testing, ALK rearrangement testing, and PD-L1 expression. EGFR and ALK mutations identify cancers that respond better to targeted oral tablets than to chemoimmunotherapy; these patients were excluded from the chemoimmunotherapy trials. PD-L1 expression predicts how strongly the cancer will respond to immunotherapy. Testing typically takes one to two weeks and changes the treatment plan in about a quarter of stage 3 patients. If you have been offered systemic treatment without these results, ask for them before treatment starts.

What is N2 lung cancer and can it be operated on?

N2 disease means the cancer has reached lymph nodes in the centre of the chest, between the lungs, on the same side as the original tumour. Until recently, N2 disease was usually treated without surgery, particularly when the nodes were bulky or involved several stations. In CheckMate 77T, perioperative immunotherapy in N2 patients cleared mediastinal lymph nodes of cancer in 57% of cases at surgery, achieved complete pathological responses in 22%, and reduced pneumonectomy rates from 14% to 1%. Patients with N2 disease are now routinely operated on at experienced centres after chemoimmunotherapy. A second opinion at a thoracic surgical centre is particularly important if your N2 case has not been reviewed by a thoracic surgeon.

Can T4 lung cancer be surgically removed?

T4 lung cancer means the tumour has grown into major structures in the chest (large blood vessels, the windpipe, the heart sac, the spine or the diaphragm), or there are tumour nodules in a different lobe of the same lung. T4 disease was for many years considered too advanced for surgery. Chemoimmunotherapy given before surgery can shrink T4 tumours sufficiently that resection becomes safely possible, particularly when the cancer responds well to the systemic treatment. At experienced robotic centres, patients with T4N1 and selected T4N2 disease are increasingly being operated on after chemoimmunotherapy. The decision is made by the multidisciplinary team after restaging scans.

Is robotic surgery possible after chemoimmunotherapy?

Yes, in experienced hands. Surgery after chemoimmunotherapy is more technically demanding because the tissues develop fibrosis and the natural anatomical planes can become obliterated. Many centres respond by converting to open thoracotomy. At high-volume robotic centres, surgeons encounter these fibrotic cases regularly and develop the technique to dissect through them robotically. Patients who have just completed four months of systemic therapy recover significantly faster from keyhole surgery than from thoracotomy. Most of Dr Okiror's private patients having surgery after chemoimmunotherapy at London Bridge Hospital have keyhole robotic surgery, with conversion to open only when anatomy demands it for safe cancer clearance.

Do I need a pneumonectomy for stage 3 lung cancer?

Pneumonectomy, removal of an entire lung, remains the right operation for some patients with central tumours or major vascular involvement. For many others, particularly after chemoimmunotherapy has shrunk the tumour, a lobectomy preserves more lung and delivers equivalent cancer control. Pneumonectomy rates vary significantly between centres. At Dr Okiror's NHS base, Guy's and St Thomas', only 1.5% of primary lung cancer operations are pneumonectomies, one of the lowest rates nationally. If you have been offered a pneumonectomy elsewhere, a second opinion at a robotic surgical centre may identify a lung-sparing alternative.

What does pCR mean in lung cancer treatment?

pCR stands for complete pathological response. It means that when the surgical specimen is examined under the microscope after chemoimmunotherapy and surgery, no living cancer cells are found anywhere in the removed tumour or lymph nodes. pCR is the strongest single predictor of long-term survival after combined treatment. In the phase 3 perioperative trials that report it, pCR rates ranged from 17% (AEGEAN) to 41% (RATIONALE-315) with immunotherapy, against 2% to 6% with chemotherapy alone. Five years ago, pCR in stage 3 lung cancer was rare.

Should I get a second opinion for stage 3 lung cancer?

Yes, particularly in three situations. First, if you were told your cancer is inoperable, especially if that advice was given more than twelve months ago or before biomarker testing was done. Second, if you have been offered a pneumonectomy. Third, if chemoradiotherapy is the only plan being discussed and you have not been formally reviewed by a thoracic surgeon as part of the MDT. Treatment has changed quickly enough that advice given a year ago may not reflect current options. Private second opinion consultations with Dr Okiror are typically available within 2–3 working days. Bring imaging, the pathology report, and any prior treatment recommendations.

Book a Consultation → Request Second Opinion

Mediastinoscopy & Lymph Node Biopsy

Whole lymph nodes removed as a day case when EBUS has not answered the question: lymphoma, molecular testing, staging

Sleeve Resection

Lung-sparing reconstruction of the airway for central tumours, the alternative to removing a whole lung

Pneumonectomy

When removing the whole lung is the correct operation: indications, fitness assessment, and life with one lung

Cancer Invading the Chest Wall

When the tumour involves the ribs: what decides operability, en bloc resection, and reconstruction of the chest wall.

Lung Cancer Surgery Overview

The full private lung cancer surgery service: all stages, robotic and keyhole resection

Your Treatment Journey

Patient guide to multi-modality treatment week by week: what happens, when, and why

Second Opinion Service

Private second opinion appointments within 2–3 days: how to prepare and what to bring

Robotic Lung Surgery

Robotic lobectomy, segmentectomy, and complex resection, including post-chemoimmunotherapy cases

Robotic Segmentectomy

Lung-sparing resection, relevant for patients downstaged by chemoimmunotherapy

Told Surgery Is Not an Option?

When you have been told surgery is not an option: the reasons given, and which of them can change

Stage 4 With One Site of Spread

Whether the lung tumour can still be removed when the cancer has spread to one place

Surgery After Radiotherapy

When an operation is considered after chemoradiotherapy, including after the PACIFIC pathway

Lung Cancer Surgery in 2026

The full pathway from diagnosis through surgery to systemic therapy

International Patients

Video consultation first, scans shared digitally, and family able to join from other countries

Journal: Let Me See Him

Commentary on who is judged fit for an operation before chemoimmunotherapy starts

Lung Nodule Pathway

Combined biopsy-and-resection pathway for indeterminate nodules, under one anaesthetic