1.What are the general types and stages of gastric cancer?
(1) In terms of tumor invasion depth and general shape, it can be divided into early gastric cancer and progressive gastric cancer.
(1) Early gastric cancer refers to early lesions limited to mucosa and submucosa regardless of the extent. It can be divided into three types: elevated type (polyp type), superficial type (gastritis type) and depressed type (ulcer type). Type II is subdivided into three subtypes, IIa (elevated superficial type), IIb (flat superficial type) and IIc (depressed superficial type). Each of the above types can have different combinations. For example, IIc+IIa, IIc+III, etc. (see the figure below). Early gastric cancer with a diameter of 5-10mm is called small gastric cancer, and those with a diameter <5mm are called micro gastric cancer.
Diagram showing the typing of early gastric cancer
(2) Intermediate and advanced gastric cancer is also called progressive gastric cancer, in which the cancerous lesions invade the muscle layer or the whole layer, and often have metastasis. There are several types as follows (see the following diagram).
Diagram showing the typology of intermediate and advanced gastric cancer
Mycosis fungoides type (or polyp-like type): it accounts for about 1/4 of advanced gastric cancer, the cancer is confined and grows mainly into the lumen, nodular or polyp-like, with rough surface like cauliflower and central erosion and ulcer, also called nodular mycosis fungoides type. If the cancer is disc-shaped, with elevated edges and central ulcers, it is called disc-shaped mycosis fungoides.
Ulcerated type: It accounts for about 1/4 of advanced gastric cancer and is divided into limited ulcerated type and infiltrated ulcerated type, the former is characterized by limited, disc-shaped cancer with central necrosis. The former is characterized by a limited, disc-shaped cancer with central necrosis, often with a large and deep ulcer; the bottom of the ulcer is generally uneven, the edge of the ulcer is elevated in the shape of a dike or crater, and the cancer is infiltrated into the deeper layers, often accompanied by bleeding and perforation. The infiltrative ulcer type is characterized by infiltrative growth of the cancer, often forming a mass with obvious infiltration to the periphery and deeper, with central necrosis forming an ulcer, often invading the plasma membrane or lymph node metastasis earlier.
(3) Infiltrative type: This type is also divided into two types, one is limited infiltrative type, in which the cancer tissue infiltrates all layers of the stomach wall, mostly limited to the gastric sinus, and the infiltrated stomach wall thickens and hardens, and the wrinkled wall disappears, mostly without obvious ulcers and nodules. If the infiltration is limited to a part of the stomach, it is called “limited infiltrative type”. The other type is diffuse infiltration type, also known as leathery stomach, in which the cancerous tissue expands under the mucosa and invades all layers with a wide range, making the stomach cavity smaller and the stomach wall thicker and stiffer, while the mucosa can still exist and there can be congestion and edema without ulceration.
④Mixed type: two or more lesions of the above mentioned types co-exist at the same time.
⑤ Multiple carcinomas: the cancerous tissues are multifocal and unconnected to each other. For example, gastric cancer occurring on the basis of atrophic gastritis may belong to this type, and it is mostly found in the upper part of the stomach body.
The arrow indicates the ulcerated area of gastric cancer
(2) There are 4 types of histotypes (pathological types).
①Adenocarcinoma: including papillary, tubular and mucinous adenocarcinoma, which are classified into three types: highly differentiated, moderately differentiated and poorly differentiated according to their degree of differentiation;
②Undifferentiated carcinoma;
(3) Mucinous carcinoma (i.e. Indolent cell carcinoma);
④Special type of carcinoma: including adenosquamous carcinoma, squamous cell carcinoma, carcinoid tumor, etc. It can be divided into two types according to histogenesis.
①Intestinal type: the cancer originates from the epithelium of intestinal glandular metaplasia, the cancer tissue is better differentiated, and the giant form is mostly myxoid;
Gastric type: the cancer originates from the intrinsic mucosa of the stomach, including undifferentiated cancer and mucinous cancer, the cancer tissue is poorly differentiated, and the giant form is mostly ulcerative and diffuse infiltrative.
In clinical practice, there are more detailed staging and typing based on tumor size, nature, infiltration depth, lymph node metastasis and distant metastasis, etc., which will not be introduced here.
2.What are the metastatic pathways of gastric cancer?
(1) Direct dissemination: Infiltrating gastric cancer can develop along the mucosa or plasma membrane directly into the stomach wall, esophagus or duodenum. Once the cancer invades the plasma membrane, it can easily infiltrate to the surrounding organs or tissues such as liver, pancreas, spleen, transverse colon, jejunum, diaphragm, greater omentum and abdominal wall. When cancer cells are shed, they can also be planted in the abdominal cavity, pelvis, ovaries and rectal bladder sockets.
(2) Lymph node metastasis: it accounts for 70% of gastric cancer metastasis. Lower gastric cancer often metastasizes to lymph nodes such as subpyloric, subgastric and para-abdominal artery, while upper cancer often metastasizes to lymph nodes such as para-pancreatic, para-pancreatic and supragastric. Advanced cancer may metastasize to periaortic and supra-diaphragmatic lymph nodes. Since the abdominal lymph nodes are in direct communication with the thoracic duct, it may metastasize to the left supraclavicular lymph node.
(3) Hematogenous metastasis: cancer cells can be found in peripheral blood of some patients, which can metastasize to liver through portal vein and reach lung, bone, kidney, brain, meninges, spleen, skin, etc.
3.What are the treatment methods of gastric cancer?
The treatment of gastric cancer is similar to that of other malignant tumors, surgery should be the first choice, and at the same time, chemotherapy, radiotherapy, Chinese medicine and immunotherapy should be reasonably combined with other comprehensive treatments.
According to the stage of gastric cancer, comprehensive treatment plan is currently adopted, which is roughly as follows. stage I gastric cancer belongs to early stage gastric cancer, which is mainly treated by surgical resection. For individual type IIa and IIc invading the submucosa and metastasis of lymph nodes, certain chemotherapy should be used. Stage II gastric cancer belongs to the middle stage gastric cancer, which is mainly resected by surgery. Some adjuvant chemotherapy or immunotherapy are available. Stage III gastric cancer mostly invades surrounding tissues and has extensive lymph node metastasis, although surgical resection is the main treatment, it should be combined with chemotherapy, radiotherapy, immunotherapy and traditional Chinese medicine. Stage IV gastric cancer is already advanced, and mostly adopts non-surgical treatment. Those who are suitable for surgery should try to remove the primary and metastatic lesions, and cooperate with chemotherapy, radiotherapy, immunotherapy and TCM as comprehensive treatment.
(I) Surgery: Surgery is divided into radical surgery, palliative surgery and short-circuit surgery.
(1) Radical surgical resection: This concept is relative, referring to the subjective judgment from the doctor that the tumor has been cut out and can achieve the effect of treatment, in fact, only part of it can achieve cure.
(2) Palliative resection: It refers to the doctor’s subjective judgment that the tumor is impossible to be completely removed, but the main tumor mass can be removed. Removing the tumor can relieve the symptoms, prolong the life span and create conditions for further comprehensive treatment.
(3) Short-circuit surgery: It is mainly used for cases with pyloric obstruction where surgical resection is impossible, and gastrojejunostomy can relieve the obstruction.
(2) Radiotherapy: including preoperative radiotherapy, intraoperative radiotherapy and postoperative radiotherapy.
(C) Chemotherapy: Except for early gastric cancer which can be treated without chemotherapy, all other progressive gastric cancers should be treated with chemotherapy. Chemotherapy includes systemic chemotherapy and intraperitoneal chemotherapy, and intraperitoneal chemotherapy refers to postoperative intraperitoneal tube placement or intraperitoneal buried chemotherapy pump and intubation chemotherapy to increase local concentration. The specific chemotherapy regimen should follow the doctor’s advice.
(iv) Immunotherapy: immunotherapy is used with chemotherapy to prolong the life of patients. Interferon, IL-2, BCG and other drugs are commonly used.
(v) Chinese herbal medicine: treatment is based on supporting the righteousness. It can counteract the side effects of radiotherapy, improve white blood cells and platelets, adjust the gastrointestinal function and improve the resistance of the body.
4.What is neoadjuvant chemotherapy for gastric cancer? What are the benefits?
Neoadjuvant chemotherapy for gastric cancer is a new concept proposed in recent years and is now being used more and more in clinical practice. The main purpose of neoadjuvant chemotherapy for gastric cancer, also known as preoperative chemotherapy, is to shrink the tumor, increase the radical surgical resection rate, and improve the treatment effect. In recent years, due to the emergence of new chemotherapeutic drugs, neoadjuvant chemotherapy for gastric cancer has become a hot spot of hope and research for the treatment of progressive gastric cancer. Neoadjuvant chemotherapy for gastric cancer has the following advantages:
(1) It can prevent the effect of chemotherapy from being affected by the alteration of tumor blood supply after surgery;
(2) Preventing resection of the primary tumor from stimulating the growth of the remaining tumor;
(3) It can reduce the stage of tumor and improve the rate of surgical resection;
(4) Reduce intraoperative dissemination, eliminate potential micrometastases, and reduce postoperative metastasis and recurrence;
(5) Chemotherapy sensitivity test to understand the sensitivity of tumor to chemotherapeutic drugs and to reasonably select sensitive drugs;
(6) Eliminate patients who are not suitable for surgical treatment.
5.What patients are suitable for neoadjuvant chemotherapy for gastric cancer? What issues should be noted in neoadjuvant chemotherapy for gastric cancer?
Generally speaking, it is more appropriate to select patients with locally progressive gastric cancer. Patients with distant organ metastases and extensive abdominal metastases will not be considered as indications for surgery even if the tumor shrinks, while patients with earlier lesions will easily lose the best opportunity for surgery because chemotherapy is ineffective. Therefore, in general, neoadjuvant chemotherapy for gastric cancer should be applied to patients with pathologically confirmed progressive stage (UICC and TNM stage II, IIIA, IIIB, IVM0) of gastric cancer, where there are objective and measurable lesions to facilitate the evaluation of the effect, where the patient’s other organ functions can tolerate chemotherapy, and where the patient’s informed consent is obtained.
Neoadjuvant chemotherapy should be based on several principles: first, do not delay surgical resection by pursuing the effectiveness of chemotherapy; surgical resection is still the best means; second, the selection of chemotherapy drugs for gastric cancer is a dynamic process, and there is no gold standard yet. Due to the relative insensitivity of many chemotherapeutic drugs to gastric cancer, neoadjuvant chemotherapy for gastric cancer can only hope for the clinical application of new chemotherapeutic drugs, including paclitaxel, doxorubicin, oxaliplatin, CPT211, etc., especially molecularly targeted drugs.
6.How to prevent gastric cancer?
Since the etiology of gastric cancer is not yet clear, there is no special prevention method. Besides paying attention to dietary hygiene, avoiding or reducing the intake of possible carcinogenic substances, eating more vegetables and fruits rich in vitamin C, etc. For the so-called pre-cancerous lesions, close follow-up should be carried out in order to detect changes at an early stage and provide timely treatment.
7.What is gastric mesenchymal tumor? What are its treatment methods and therapeutic effects?
Among the non-epithelial tumors of the stomach, malignant lymphoma is the most common, followed by smooth muscle tumors, nerve fiber or nerve sheath tumors, rhabdomyosarcoma, etc. With the advancement of pathological studies, especially the application of immunohistochemistry and electron microscopy, it was found that many cases originally referred to as smooth muscle tumors lacked corresponding features in immunohistochemistry or ultrastructure, and the previous kind of classification and nomenclature were obviously not scientific and rigorous enough. In the 1990s, the concept of gastric stromal tumor (GST) was introduced to emphasize the histogenetic uncertainty of this type of tumor. The current term gastric stromal tumor consists of a large group of primary non-epithelial tumors of the stomach other than lymphomas, which arise from cells in the organ laminae and are often confusing to recognize because of the variability of differentiation pathways. Tumors that lack differentiation features or differentiate in both smooth muscle and nerve directions are currently referred to collectively as gastric mesenchymal tumors, while terms such as smooth muscle tumor (sarcoma) or nerve sheath tumor may still be used for those with clear evidence of differentiation.
Surgery is now recognized as the treatment of choice for gastric mesenchymal tumors. For limited lesions, local wedge resection can achieve similar results to regular gastrectomy as long as the sarcoma is completely removed. It is believed that even if there is residual microscopic margin after local excision, it does not affect postoperative survival. This is because most of these tumors grow in a gastric shape, and a positive margin is not as important as the dispersal of tumor cells into the abdominal cavity. Even if the tumor invades adjacent organs or has peritoneal dissemination, surgical resection should be pursued. If all visible tumors can be resected without disruption, similar results as in limited lesions can still be achieved. Since lymph node metastases are indeed rare in this disease, extensive or regional lymph node dissection is not required. Although the overall prognosis of gastric mesenchymal tumor is better than that of gastric cancer, the 5-year survival rate of patients is still only 50%, which indicates that it is still a relatively poor prognosis tumor and proves that the efficacy of surgery alone is still limited. Especially for high-grade gastric mesenchymal tumor, although “curative resection” is performed, the recurrence rate is still high, and effective adjuvant therapy with multiple programs should be carried out.
8.What is duodenal congestion?
Duodenal stasis is a clinical syndrome caused by the obstruction of the duodenum from various causes, resulting in the proximal dilatation of the obstructed part of the duodenum and the accumulation of chyme. There are many causes of duodenal stasis, but the superior mesenteric artery compresses the duodenum and forms the majority of stasis (50%), which is also called superior mesenteric artery syndrome. Other causes include
① Congenital anomalies: such as congenital peritoneal girdle compression and pulling to block the duodenum; congenital stenosis or occlusion of the distal duodenum, compression of the descending duodenum by the annular pancreas; megaduodenum due to duodenal dysplasia, and severe prolapse of the duodenum due to congenital mutations, which can fold the duodenojejunal angle and close it, resulting in congestion.
②Tumors: benign and malignant duodenal tumors; retroperitoneal tumors such as renal tumors, pancreatic cancer, lymphoma; metastatic cancer of the duodenum, adjacent enlarged lymph nodes (cancer metastasis), mesenteric cysts or abdominal aortic aneurysm compressing the duodenum.
③Infiltrative disease and inflammation of the distal or proximal jejunum of the duodenum; such as progressive systemic sclerosis, Crohn’s disease, and inflammatory adhesions or compression of diverticula causing constriction.
④Adhesions occurring after gallbladder and gastric surgery pulling the duodenum; adhesions, ulcers, strictures or input collaterals syndrome after gastrojejunostomy.
⑤ Other congenital anomalies: duodenal inversion, duodenal obstruction due to gallbladder duodenal cords; anterior portal vein malformation of duodenum; abnormal position of Fate’s jugular (common bile duct opening in the third part of duodenum), etc.
The transverse duodenal segment is located behind the peritoneum and crosses the third lumbar vertebra and the abdominal aorta from right to left, and is crossed by the superior mesenteric vascular nerve bundle in the mesenteric root in front of it (see the figure below). If the angle between the two is too small, the duodenum can be compressed. The superior mesenteric artery usually divides at the level of the first lumbar vertebra and is at an angle of 30° to 42° with the aorta. In addition, the following five factors are also responsible for mechanical obstruction.
① The superior mesenteric artery is too long or too short;
②Variation of the superior mesenteric artery, which divides from the abdominal aorta at too low an angle or at a narrow angle when dividing;
(iii) abnormally large vein pressing across the front of the duodenum;
(iv) anterior spinal deformity reduces the space occupied by the duodenum; the weight of the intestinal canal pulls on the mesenteric root in lean and long types or those with visceral prolapse.
Schematic diagram of the anatomical location of mesenteric vessels
9.What are the manifestations of duodenal congestion? How to treat duodenal congestion?
Acute duodenal obstruction often occurs when the trunk is immobilized by a cast or traction and causes acute signs of gastric dilatation. Chronic obstruction is the most common type clinically, and erratic, nausea and vomiting are common symptoms, mostly after meals, and vomit contains bile, which can be alleviated by changes in position, such as lying on the side, prone, or in the chest and knee position. If it cannot be relieved, long-term attacks can lead to wasting, dehydration and general malnutrition.
Those without obvious symptoms may not need to be treated. Intravenous nutrition including fat emulsions, nasal cannula decompression and antitussive drugs are given during acute attacks to treat acute gastric dilatation. Usually it is advisable to have small and frequent meals, make knee-chest position for half an hour after meals and strengthen abdominal muscle exercise. If conservative medical treatment is not obvious, surgical treatment can be used. Surgical modalities are available as follows.
① Free the duodenal ligament;
② Duodenojejunostomy;
③ Duodenal repositioning.
10.Is duodenal diverticulum common? What are the manifestations of duodenal diverticulum?
The exact incidence of duodenal diverticula is difficult to count, because many diverticula do not produce clinical symptoms and are not easily detected in time. The detection rate of duodenal diverticula has been reported to be 1% on barium gastrointestinal examination and up to 22% on autopsy. 90% of diverticula are single and 80% are located in the second part of the duodenum, especially in the medial wall or concave surface. Duodenal diverticula occur mostly in patients between 40 and 60 years of age, and are rarer under 30 years of age. Its incidence does not differ among particulars.
There is no typical clinical presentation of duodenal diverticula and the symptoms that occur are mostly due to complications. Epigastric fullness is the more common symptom and is due to diverticulitis. It is accompanied by belching and vague pain. The pain is irregular and is not relieved by acid control drugs, and nausea or vomiting is common. When the diverticulum is full of food and swollen, it can compress the duodenum and cause partial obstruction. The vomit is initially stomach contents, then bile or even blood, which can be relieved by vomiting. When the diverticulum is complicated by ulceration or bleeding, the symptoms resemble ulcer disease or blood in the stool, respectively. When the diverticulum compresses the opening of the common bile duct or pancreatic duct, it can cause cholangitis, pancreatitis, or obstructive jaundice. When the diverticulum is perforated, it presents with symptoms of peritonitis.