Surgery can be a viable option

Professor em. Paul Van Schil

Interview with Professor em. Paul Van Schil

While chemotherapy is likely the most well-known treatment for lung cancer, it is by no means the only one. Surgery, for example, also plays a crucial role. Let’s delve deeper.

Professor emeritus Paul Van Schil, a thoracic and vascular surgery professor at the University of Antwerp and a consultant at the University Hospital of Antwerp, begins by discussing the TNM staging system for tumors.

Depending on the stage, tumors are classified according to the so-called TNM Classification. What is that classification about?

Paul Van Schil The T in the TNM Classification stands for tumor and N for nodule, which refers to the lymph nodes. This is important because tumors can spread through the lymph nodes. The M, metastasis, refers to metastases elsewhere in the body that have spread via the bloodstream. The primary goal of this classification is prognosis, though it may also inform treatment plans. 

For lung cancer, there is now a ninth edition of the Classification, which further refines the previous edition. Nothing changes for the T under the ninth edition, focusing on the size of the tumor and whether or not the primary tumor – the tumor itself – has grown into neighboring organs. There is an important change in the N, lymph nodes, however. If the tumor grows and almost reaches the lung, the hilar lymph nodes are affected. It can also extend further along the (bifurcation of the) trachea. These are the mediastinal lymph nodes. The mediastinum is the space between the lungs. This is referred to as N2, where the tumor has spread further away, which is now subdivided into N2a and N2b. In N2a, one lymph node station in the mediastinum is affected; in N2b, multiple stations are affected and the prognosis is clearly worse. Hence the division, which also allows for a different treatment. Some N2a patients are immediately eligible for surgery. For N2b patients we provide other forms of treatment, such as a combination of chemotherapy and radiotherapy.

The ‘M’ category traditionally classifies limited chest metastasis (M1a), a single distant metastasis (M1b), such as in the brain or bone, and multiple metastases (M1c). The third division, multiple metastasis (M1c), is now further divided into M1c1 and M1c2. M1c1 means that multiple metastases are present in a single organ system, M1c2 signifies multiple metastases in multiple organ systems, such as the adrenal gland and the liver.

Are minimally invasive and robotic surgeries also being used to treat lung cancer?

Paul Van Schil The goal of any surgical procedure is a complete R0 resection, meaning total tumor removal, clear microscopic margins, and the removal of sufficient nearby lymph nodes for pathological analysis.  

In the past, incisions were quite large. An incision in the chest (thoracotomy), for example, would cut through several layers of muscle to reach the tumor between the ribs. This evolved to muscle-sparing procedures that minimize injury to the large back muscle, promoting faster postoperative recovery.  

Over the past 20 years, we have evolved to minimally invasive procedures, using smaller incisions (thoracic ports) to access the chest cavity and perform good oncological surgery. Video equipment is used for this purpose: video-assisted thoracic surgery (VATS). It employs a small camera inserted through one port, with surgical instruments inserted through adjacent ports, allowing the surgeon to monitor the operation on a screen.  

"Over the past 20 years, we have evolved to minimally invasive procedures, using smaller incisions."

Recently, robotic-assisted thoracic surgery (RATS) has also been introduced, which also involves just a few incisions. A major advantage is the introduction of the double camera via one port. The surgeon sits next to the patient, works at a console and sees a three-dimensional picture. Flexible instruments are inserted through other ports, enabling surgery within the thorax much like traditional open surgery, but with smaller incisions.  

This 3D view broadens our capabilities significantly, providing a highly effective approach for the patient with faster recovery times. However, the surgery must remain oncologically sound. VATS and RATS are ideal for small, non-invasive tumors that haven’t grown into surrounding organs. For tumors around 9–10 cm that have grown into the surrounding organs, muscle-sparing thoracotomy remains necessary because they cannot be removed via a small incision.  

Each patient requires an individual assessment to determine the optimal access route and the best surgical approach, to ensure that the surgical procedure is oncologically effective and ensure the fastest possible recovery for the patient. 

More lung-sparing surgeries are being pursued. What does that entail?

Paul Van Schil Until a few years ago, patients with adequate heart and lung reserve would undergo a lobectomy, where one lung lobe is removed. The right lung has three lobes; the left, two. For very large tumors, a pneumonectomy, or removal of the entire lung, may be necessary. 

A 1995 study showed higher relapse rates when less than a full lobe was removed, so lobectomy became the standard treatment. Back then, only large tumors were detected due to the lack of advanced CT and PET scans, and lung cancer screening wasn’t yet available. Recently, however, advanced imaging has allowed us to detect much smaller tumors, some less than a centimeter in size. This raises the question of whether a lobectomy is still necessary for such cases, or if a more conservative approach removing less lung tissue might be preferable.  

"Recently, however, advanced imaging has allowed us to detect much smaller tumors, some less than a centimeter in size."

Lobes consist of several segments. When less than a full lobe is removed, this is called a segmental resection or wedge resection. A wedge resembles a slice of pie and can be excised from lung tissue with a stapling device.  

A Japanese study and a more recent US study compared lobectomy with segmental or wedge resection. They found that for tumors smaller than 2 cm without lymph node involvement, segmental or wedge resection yielded comparable results to lobectomy, even showing better survival rates. This is because many patients undergoing lobectomy later died from other causes unrelated to primary lung cancer. However, the results are comparable only when the tumor is fully excised. But for small tumors with negative lymph nodes, all three techniques are valid options.

What role does surgery play alongside other therapies?

Paul Van Schil With the advances in immunotherapy, we’re still determining surgery’s exact role. Combination treatments are increasingly used: chemotherapy, immunotherapy, surgery and radiotherapy or possibly combined with targeted therapies. Targeted therapy employs drugs tailored to specific genetic mutations or abnormalities within the tumor. 

The consensus is that immediate surgery is preferred for small tumors that can be completely removed (R0 resection). Following a pathological analysis and multidisciplinary review, patients with certain mutations may receive postoperative chemotherapy, immunotherapy, or even radiotherapy, especially if unexpected positive nodes are found. This is assessed on a case-by-case basis.  

In the past, chemotherapy was mainly given postoperatively (adjuvant chemotherapy) for large tumors or positive nodes. However, studies showed only a 5% survival benefit over the long term, similar to preoperative chemotherapy (induction or neoadjuvant chemotherapy). With immunotherapy, new protocols are being explored—both pre- and post-surgery—to improve outcomes.  

The aim isn’t always tumor shrinkage but to enhance overall survival and prevent rapid metastatic spread. There’s ongoing debate about how best to implement this in practice, and more definitive answers will come from ongoing studies.