Surgery

What is it ?

Surgery is used in many medical conditions, particularly in oncology.

Most often, it is used with a curative intent, meaning to completely remove the cancerous tumor. This is referred to as oncologic surgery.

However, there are other types of interventions as well.

Functioning of oncologic surgery

The general principles of surgery in oncology don’t differ from surgery in other contexts. However, only a surgeon experienced in this field and in rare tumors should perform this surgery.

Expertise is often required. Doctors may use this treatment at different stages of the cancer.

Diagnostic surgery

The goal of this surgery is to make a precise diagnosis of cancer by performing a biopsy if it could not be done more easily and/or by exploring the tumor's environment to determine the stage of the disease (e.g., exploratory laparoscopy in ovarian cancer).

Curative surgery can be performed at the same time as diagnostic surgery if it is feasible.

Curative surgery

In oncology, surgery is primarily focused on localized cancers. When tumor cells circulate in the blood, it leads to an advanced stage of cancer with metastases. Therefore, oncologic surgery is not always necessary.

This is why the medical team must perform a staging assessment of the disease before confirming oncologic surgery.

Curative surgery involves the complete removal of the tumor with safety margins that contain no visible tumor to the naked eye :

• If the margins are clear, the resection is called R0.
• If the cancer has microscopically infiltrated the margins, as determined by pathological examination, the resection is called R1. In such cases, additional surgery may be proposed to achieve clear margins.
• If the surgeon is unable to remove the entire tumor, leaving a visible residual tumor, this is referred to as an R2 resection.

The goal of preoperative imaging is to avoid this scenario, which would be considered a failure of oncologic surgery.

In addition to tumor removal, it is often necessary to analyze the lymph nodes that drain the tumor site. These lymph nodes are typically the first locations where tumor cells spread before they reach other organs.

There are two techniques for lymph node analysis :

• Lymph node dissection : this involves removing the entire chain of lymph nodes for analysis. If the lymph nodes are found to be invaded by cancer cells, additional treatment, such as radiotherapy and/or chemotherapy, will be recommended.
• Sentinel lymph node biopsy : a less invasive technique. First, the surgeon injects a marked substance to identify the first lymph node(s) that act as a relay between the tumor and the general circulation. The pathologist then removes and analyzes these lymph nodes on-site (frozen section examination). If tumor cells are present in the lymph nodes, a full lymph node dissection is performed. If not, the rest of the lymph node chain is left in place.

Cytoreductive surgery

As mentioned earlier, oncologic surgery should only be performed when there is certainty of removing the entire visible mass.

In rare cases, such as peritoneal involvement, a maximal but still incomplete resection can offer a survival benefit when combined with additional treatments, particularly chemotherapy. The indication for this surgery must be validated during a multidisciplinary consultation meeting (MCM).

Surgery for metastases

Similarly, exceptions can be made in cases of metastatic disease.

If metastases are present from the outset but are few in number (oligometastatic disease: 1 to 3, or even up to 5 secondary lesions), surgery for the primary tumor and its metastases may be proposed if all can be accessed with curative surgery and sufficient safety margins. Additional treatment, such as chemotherapy or radiotherapy, may be necessary.

If metastases appear later and are again few in number, surgery may be proposed by the oncologist. Beforehand, doctors will have discussed this option during a multidisciplinary tumor board meeting (RCP), comparing it with other possible treatments such as stereotactic radiotherapy, interventional radiology (radiofrequency ablation, cryoablation), and possibly complemented by chemotherapy.

Palliative surgery

This type of surgery is offered when the tumor causes significant symptoms (such as a painful mass or skin complications like bleeding or infections). The goal is to relieve the patient, but it is not intended to treat the cancer itself.

Prophylactic surgery

This refers to one or more procedures that an oncologist may recommend even before the onset of cancer. There are hereditary genetic predisposition syndromes that increase the risk of cancer (for example, BRCA1 and BRCA2 mutations, which are responsible for breast and ovarian cancers).

An oncogeneticist may prescribe a test to confirm or rule out the presence of a mutation if there is suspicion. If the mutation is identified, a significant risk is confirmed, and the doctor may suggest preventive surgery (in the case of BRCA mutations: double mastectomy +/- oophorectomy, meaning the removal of both breasts and ovaries). The medical team must discuss this option with the patient. The benefit-risk ratio is less clear than in the case of a diagnosed cancer, and the consequences can be significant (infertility, surgical risks, etc.).

Reconstructive surgery

Reconstructive surgery is not a cancer treatment. It addresses complications from cancer treatment, specifically aiming to restore self-image and repair aesthetic and functional damage. The surgeon can perform it at the time of tumor removal, or a specialized practitioner can carry out the procedure at a later stage.

Adverse effects of oncologic surgery

The adverse effects of oncologic surgery are those inherent to any surgical procedure :

• Anesthetic risks
• Infection at the surgical site
• Healing complications: these may be more common if chemotherapy and/or radiotherapy were performed beforehand.
• Residual pain

Indications

Cancer professionals (oncologists, surgeons, radiotherapists, radiologists, etc.) discuss the surgical indication during a multidisciplinary consultation meeting (MCM).

The decision will validate the surgery itself as well as its role within the overall therapeutic strategy.

Neoadjuvant treatment (such as chemotherapy) may precede the surgery, and adjuvant treatment (including chemotherapy, radiotherapy, hormone therapy, immunotherapy, etc.) may follow it.