Can esophageal cancer be removed as early as possible under endoscopy? The following conditions must be met

Author: Wu Qi, Chief Physician, Peking University Cancer Hospital

Reviewer: Shang Zhanmin, Chief Physician, Beijing Chaoyang Hospital (West Campus), Capital Medical University

Currently, gastroscopy is the most common examination method for detecting esophageal cancer. If esophageal cancer is in the early stages, it can be completely removed under endoscopy, which causes relatively little trauma to the patient.

Figure 1 Original copyright image, no permission to reprint

1. Which early esophageal cancers can be removed endoscopically?

First of all, in terms of the depth of lesion invasion, the esophageal mucosa is divided into three layers: M1 is the lesion limited to the mucosal epithelial layer, M2 is the lesion infiltrates into the mucosal propria, and M3 is the lesion infiltrates into the muscularis mucosa.

The absolute indications for endoscopic surgery are M1 and M2. When it reaches M3 or SM1, that is, the lesion infiltrates to the upper 1/3 of the submucosal layer, it is considered an expanded indication. At these two levels, there is a 2%-8% chance of lymph node metastasis. Postoperatively, regular CT examinations must be performed to follow up for metastasis of the mediastinal lymph nodes.

Secondly, in terms of the nature of the lesion, squamous cell carcinoma is divided into differentiated and undifferentiated types. The undifferentiated type is relatively more malignant. If it invades the muscularis mucosa, which is M3, or the superficial submucosal layer, which is SM1, the risk of lymph node metastasis will be higher.

For these patients, additional surgical procedures or radiotherapy to the mediastinum area are required to avoid incomplete endoscopic resection and later metastasis.

This is something that must be grasped when considering surgical indications. The above conditions can be removed under endoscopy.

Once lymph node metastasis occurs, endoscopic surgery becomes a contraindication because endoscopic surgery is currently unable to achieve simultaneous lymph node dissection.

In addition, the lesions invade the submucosal layer relatively deeply; the degree of differentiation is relatively poor, including basal cell esophageal cancer; some patients take hormone drugs all year round, causing degeneration and softening of the esophageal wall muscles, which is prone to perforation; some cannot tolerate surgery because the surgery requires general anesthesia. These situations are not suitable for endoscopic resection.

2. How is endoscopic resection of early esophageal cancer performed?

For patients with early esophageal cancer, the diagnosis and staging have been completed, and it has been determined that endoscopic treatment is appropriate. The corresponding preoperative examinations should be completed, including anesthesia evaluation, and surgery can be performed if there are no problems.

After general anesthesia, use a scalpel to make a mark 2-3 mm outside the edge of the entire lesion. Then inject some drugs into the submucosal layer to lift and separate the mucosal layer and the muscular layer. The lesion is completely peeled off along the layers of the submucosal layer, like peeling an orange. After the entire lesion is removed, the surgical wound needs to be treated in a certain way, and some large blood vessels exposed on it need to be electrocoagulated. Some patients have very thin esophageal walls or perforations, which need to be repaired. In addition, the surface is routinely sprayed with some drugs for protection.

Figure 2 Original copyright image, no permission to reprint

The diseased tissue that is cut off should be removed in time and the specimen should be fixed for later pathological examination.

This is the general process of endoscopic submucosal dissection.

Large mucosal resection is relatively simple. Just use a snare-like tool to encircle the lesion.

Figure 3 Original copyright image, no permission to reprint

If the patients meet the indications for endoscopic surgical resection and are given standardized and compliant resection, early esophageal cancer can be cured.

3. How to follow up after endoscopic resection of early esophageal cancer?

Generally, a follow-up examination is required within one month after the operation. The follow-up examination mainly involves gastroscopy. If the lesion exceeds the corresponding indications, some additional CT examinations are required.

First, it is important to evaluate the effect of surgical resection to determine whether complete radical resection has been achieved, whether it is within the scope of indications, or whether it has exceeded the indications, to determine whether other treatments are needed after surgery; second, to look at the wound healing situation and make adjustments to medication and diet.

In the first year after surgery, gastroscopy should be performed every 3 months; in the 2-3 years after surgery, examinations should be performed every 6 months; in the 4-5 years after surgery, examinations should be performed once a year. Generally, follow-up is performed until the end of the 5th year after surgery. If there is no recurrence or metastasis within 5 years, or no tumors grow in other parts, it can be called clinical cure.

If the cancer recurs after surgery, if it recurs at the edge of the previous incision, endoscopic resection can be performed again; if it recurs at the base, it means that the cancer was not completely removed. It may be that the indications were not properly judged. The lesion is too deep and will recur at the base. In this case, endoscopic mucosal resection is not suitable and a complete radical resection of the esophagus and surrounding lymph nodes is required.