Pathology of stomach cancer

2021-01-27 12:00 AM

About 85% of stomach cancers are adenocarcinomas, 15% are lymphomas-non-Hodgkin and leiomyosarcomas, and secondary tumours are uncommon.

Outline

Stomach cancer is at the forefront of gastrointestinal cancers. Although the mortality rate has decreased over the past 60 years, the rate of disease compared with other cancers is still high.

Epidemiology

The incidence of stomach cancer varies from country to country. In Japan, China, Chile, and Ireland the morbidity and mortality rates have tended to decrease significantly. In the US, in recent years, the rate of this disease has decreased (in men from 28 / 100,000 to 5 / 100,000 and for women from 27 / 100,000 to 2, 3 / 100,000) the ratio between men / women is 1. , 7, median age 63. Mortality decreased from 33 / 100,000 in 1930 to 3, 7 / 100,000 in 1990. In 1996, about 22,800 new cases of stomach cancer were diagnosed and had 14,000 people died.

In Japan, the rate of stomach cancer is 69 / 100,000, the average age is 55, and the incidence is related to the race (Black Americans, Indians, and Hispanics fold cancer rates. 2 times that of white Americans). In addition to the environment, substances known as carcinogen from food have also been linked to the disease. In terms of epidemiology, the risk of stomach cancer is high in the lower socioeconomic class.

Particularly in Vietnam, there are no specific statistics

Gastric adenocarcinoma

Approximately 85% of stomach cancers are adenocarcinomas (gastric adenocarcinomas), 15% are lymphomas-non-Hodgkin and leiomyosarcomas, and secondary tumours are uncommon.

Gastric adenocarcinoma is divided into two types: diffuse type and small intestine type.

Pathology

Type of small intestine:

It is a common stomach cancer. The proliferating cells have a glandular tubular structure. Dysplasia is characteristic of this form of the disease, with a high degree of dysplasia in the advanced phase as well as in the silent period lasting 5 to 15 years. Dysplasia can occur against the background of atrophic gastritis as well as in an area with intestinal dysplasia and both combined increase the risk of gastric adenocarcinoma. Lesions in the form of ulcers, common in gastric cavities and curvatures and often with a long pre-cancer progression. The tumour has a clear boundary, metastasized blood sugar to the liver and lymphatic route to the lymph node, the rate is more common in the elderly.

Spillover type:

This is a less differentiated cancer than the bowel type. The proliferative cells infiltrate into plaques, thickening the stomach wall. It develops everywhere in the stomach, including the mind, which loses the ability to simplify the stomach (called the linitis plastica or the bladder) the ability to spread far away. It infects the peritoneum and retroperitoneal, diffuses into the lymphatic ducts, bones. This type is most commonly found where stomach cancer is considered low-risk as in the United States and more common in younger people. This type has a worse prognosis than the gut type. There is also another form Adenosquamous with very bad prognosis because of rapid progression and early metastasis.

Depending on the depth and width of the tumour, it is divided into surface cancer and invasive cancer.

Surface cancer:

Only limited to the mucosa and submucosa, not to the muscle layer, manifesting 3 forms:

Typ I: Convex or in the form of a polype .

Typ IIa: Mucosal folds are raised, Typ IIb: The mucous membrane is flat, Typ IIc: Lean is slightly subsided.

Typ III. It is a cavernous digging, surrounded by mucous nodules. There are cases where a combination between the types makes it ulcerative.

Invasive cancer:

Crosses the mucous layer to the muscular layer, serosa. There are 3 types.

Lapar cancer: A mass on the hard base and on the inside of the stomach, no ulcers or necrosis.

Ulcerative cancers: The mucosal folds converge beyond the oedema ring.

Infectious carcinoma: Lesions spread soaked in the entire stomach (corpus type).

Stomach cancer usually spreads towards the oesophagus at the gastroesophageal junction when the cancer is located in the body, aneurysm. In the cavity, cancer often spreads down and causes pyloric stenosis, but invasions through the duodenum are rare. Cancer can spread to the small junction, the large junction, the spleen, the colon, the pancreas, and the nearby lymph nodes.

Stomach cancer often metastasizes to the lungs, liver, brain, bones, adrenal lymph nodes (Virchow's lymph nodes), left axillary lymph nodes (Irish lymph nodes), peri-navel lymph nodes (Sister Mary Joseph's lymph nodes), ovaries (Krukenberg's tumours), cornea, rectum

Risk factors and pathogenesis of stomach cancer

Factors have been confirmed:

Severe gastric dysplasia: Common in inflammatory and ulcerative forms with gland dysplasia. About 10% may progress to stomach cancer after 5 to 15 years.

Chronic atrophy of the stomach, intestinal dysplasia.

Familial adenocarcinoma (FAP): Is associated with cancer.

Stomach adenomas.

Barrette of the oesophagus: Cancer of the heartland.

Helicobacter pylori bacteria: Causes chronic gastroenteritis, atrophic gastritis, peptic ulcer, gastric lymphoma (MALT) and stomach cancer.

Factors that can cause stomach cancer:

After 15-25 years of gastric bypass surgery, the rate of cancer is 50-70% because of dysplasia near the junction.

Malignant anaemia in the elderly: Associated with chronic gastritis type A in the gastrointestinal tract with the emergence of antibodies against parietal cells and antibodies to internal factor.

Menetrier Disease (Hypertrophic Gastritis): There are many suggestive factors that have been linked to cancer. But there is no evidence regarding glandular polyp, although teeth that exhibit an enlarged appearance sometimes appear as polyp.

Stomach hamartomas.

Food: It has been found that people who overeat and prolong foods preserved with salted, smoked or dried have high levels of nitrates often associated with stomach cancer. Under the effect of bacteria Nitrate will be turned into nitrosamine, a carcinogen.

Bacteria

Eat fewer fresh fruits and vegetables: Suggested by vitamin C to inhibit the conversion of nitrite to nitrosamine. In the United States, a decrease in the incidence of stomach cancer is associated with a decrease in intestinal lesions in the lower stomach area; suggests that, better food preservation, good ability to freeze food (which inhibits bacteria growth) can be widely available to all walks of life, reducing the incidence of cancer. stomach.

Socio-economic status also plays an important role: The rate of stomach cancer is high in low-living countries, the higher the chance of infection.

Tobacco and alcohol are also considered risk factors.

Doubt factor:

Hyperplasia polyps.

Basal region polyps.

Benign stomach ulcers.

Type A blood is more prone to stomach cancer than other groups. Perhaps this blood type, the gastric mucosa's ability to protect against tumour-causing factors, is weaker than other blood types.

Clinical characteristics

In the early stage: 80% often have no symptoms, the rest often have symptoms of ulcers, nausea, loss of appetite, decreased appetite, abdominal pain, stomach bleeding, weight loss, difficulty swallowing.

In advanced stage: Significant signs of weight loss (60%), nausea, vomiting, loss of appetite, feeling of heaviness after eating, epigastric pain, sometimes ulcer pain, loss of alcohol and tobacco There may be a fever. Mild bleeding and oozing are most common, with symptoms of hypochromia. Stenosis of the oesophagus makes it difficult to swallow in high cancer. Pyloric stenosis, pre-pyloric stenosis causes abdominal pain, vomiting, dehydration.

Abdominal Examination: Sometimes normal or palpable at times of lump or vagina in the epigastric region. Stomach cancer can spread to the serosa sticking to neighbouring organs such as the pancreas, colon, lymph nodes, connective membranes, metastases to the peritoneum, ovaries (Krukenberg's tumours), peri-navel lymph nodes (Sister Mary Joseph nodules), metastasis to regional and Virchow lymph nodes (parietal lymph nodes), bones, lungs, liver, spinal cord, brain.

General examination: Anaemia, oedema or jaundice, ascites may appear.

Uncommon clinical manifestations: (Signs of near-tumour): Hypoplasia of the marrow, dark pigmentation patches in the armpit area (Acanthosis nigricans), Trousseau's syndrome, dermatitis, microscopic haemolytic anaemia, keratosis sebaceous gland, membrane kidney disease.

Subclinical

About blood:

Increases Fibrinogen and other proteins of the inflammatory response.

VS medium increase.

Anaemia: Reduced red blood cells.

Carcinogenic embryonary antigen (CEA) quantification: Increased, seen only in the late stage in 1/2 of cases, useful in monitoring the progression after gastric bypass surgery.

Gastric juice:

The analysis showed that acidosis was caused by previous gastric atrophy or in association with cancer.

Endoscopy and biopsy:

Advancement in superficial cancer diagnosis, for locating, spreading condition of tumour, bleeding condition.

Cytology test:

B deny that comb cell.

Supersonic:

Abdominal, laparoscopic ultrasound, abdominal scanner: assess the width, depth and detect metastasis of cancer.

Bone marrow test:

Cerebrospinal puncture, skull scanner, skin biopsy: when metastasis suggests.

X-ray:

With conventional Baryte staining technique, we have the following images:

The missing picture with sharp angle inserted into the wall of the stomach in cancerous warts or ulcers.

Shrinkage and stiffness in widespread laxative cancer.

The wedge-shaped appearance (triangular image or apple core) in ulcerative cancers.

The double contrast technique helps to diagnose small lesions lying close to the shore, corresponding to 3 types of pathology. (type 1: polypoid, type 2: shallow ulcer, type 3: burrow).

Diagnose

The earlier the diagnosis, the better chance of cure (Tis stage), and longer lifetime. Detection is based on X-ray and endoscopic biopsy series. In Japan, the early detection of stomach cancer is 90% of the cases compared with 40% in the United States. This is the T1, T2 stage and usually has few symptoms.

In the late stage, the symptoms are more obvious and severe, the distant metastasis can be, and the treatment is very limited.

During endoscopy, a biopsy of at least 10 pieces is required. In the body, a deep biopsy is required. During the scar-making period during treatment, 2 biopsies are required.

Prognosis

Depending on the histology of cancer, the location of the tumour, its local invasion, and metastasis.

Good prognosis: Early-stage stomach cancer (mucosal damage, submucosa)

Cancer of small bowel type has a clearer limit, so the prognosis is better than diffuse cancer, cancer of the heartland and large aneurysms due to slow diagnosis, so the prognosis is worse than cancer of the lower stomach. The prognosis is worse.

TNM classification allows assessment and prognosis of survival but also based on the size of the tumour (T), lymph node damage (N) and the appearance of metastasis (M). T1: U has not yet exceeded the mucosa, corresponding to surface cancer. T2: U goes to muscle class.

T3: U to the serosa.

 

T4: U sticks to neighbouring organs. N0: No lymph nodes.

N1: Only lymph nodes near the stomach, around 3 cm.

N2: Hach area is intrusive but can be removed. N3: extensive lymph node metastasis: Cannot be removed.

M0: No organ metastasis.

M1: metastasis.

Stage1: Only in the stomach: The relative rate is 26-28%

Stage2: There are abdominal lymph nodes: 43-49%.

Stage3: There are lymph nodes on the diaphragm.

Stage 4: Spread injury (stages 3 and 4 are 13-31%).

Other types of stomach cancer

Primary gastric lymphoma

Epidemiology:

Rarely, adenocarcinoma, accounting for less than 15% of all stomach cancers and about 40% of lymphomas of the digestive tract. About 1/3 of cases do not have lymph nodes. This category has increased over the past 20 years.

Gastric lymphoma can be primary or secondary, seen at all ages, especially after 50 years of age. H. pylori infection seems to increase the risk of developing gastric lymphoma especially the MALT (mucosa-associated lymphoid tissue) type. The form of gastric lymphoma is diverse, tumours arise from submucosal organs that spread to the inside of the wall, over a large area, or form an intact mass. There the mucosa is nodular, thickened, sometimes eroded, large masses create polyps, or sometimes spread to the duodenum.

Symptom:

Weight loss, epigastric pain, nausea and vomiting, anaemia, fever, bleeding, rarely perforation. A clinically palpable tumour (1/3 of cases)

Diagnose:

Distinguishing from gastric Adenocarcinoma is sometimes difficult to rely on endoscopy and biopsy (sometimes deep biopsy). No X-ray images are specific, but a combination of polyp lesions and flashes in the same patient is suggestive of the diagnosis.

Metastasis:

Nodules, liver, bone marrow, spleen, peritoneum, spleen.

Prognosis:

Better than adenocarcinoma, 40% - 60% of patients live 5 years. Prognosis of various stages of gastric lymphoma according to Ann Arbor.

Stage1: Only in the stomach: The relative rate is 26-28%.

Stage2: There are abdominal lymph nodes: 43-49%.

Stage3: There are lymph nodes on the diaphragm.

Stage 4: Spread injury (stages 3 and 4 are 13-31%).

Smooth muscle sarcoma

Account for 1% - 3% Malignancy is derived from muscles. Damage to the stomach stem, causing ulcers and bleeding. It rarely penetrates nearby organs and does not spread to the lymph nodes but can spread to the liver and lungs.

The carcinoid stomachs

Account for 0, 3% of stomach cancer. This type of endocrine tumour produces substances with many biological activities such as serotonin, histamine, somatostatin and kinins but does not cause symptoms of flushing, diarrheal and cardiopulmonary symptoms like in carcinoid syndrome. Lesions are usually in the submucosal layer but can be ulcerated to the muscle layer. Lesions in many places poorly increased blood gastrin.

Other mesenchymal tumours

Malignancy originates in nerve tissue.

Sarcoma vascular Kaposi

Mainly in the skin, internal organs, especially the stomach. Manifests as submucosal nodules, sometimes dark red in colour, 1-2 cm in diameter. Common in AIDS patients or patients undergoing immunosuppressive therapy.

Secondary gastric tumour

Usually rare, originating from malignant melanoma, cancers of the breast, lung, pancreas, testicles, and parotid glands. X-ray picture resembles lymphoma or diffuse gastric tumour. Diagnosed by endoscopy, biopsy

Treatment

Treatment of gastric carcinoma

Surgery:

Surgery is still the leading indication, early detection, the higher the outcome after surgery (5-year survival rate is 37% in Japan and 10-15%: in the United States).

Cut at least 5 cm from the edge of the tumour.

Partial resection: If there is surface cancer in the lower third of the lymph nodes, it is enough to cut the stomach partially.

Full cut: Cancer for the middle and upper gastric bypass is better than half or upper extremity, complete lymph node removal.

Combined splenectomy when stomach cancer is at a large curve.

Cardio: Cut the end of the oesophagus and the top of the stomach.

Stent, laser cut with haemostasis with Nd: YAG (Argon and Neodymium: Yttrium aluminium garner) through endoscopy in case the tumour is bleeding and over the surgical stage.

Temporary medical treatment:

Abdominal surgery found distant metastases.

Non-surgical treatment:

Chemotherapy:

Improvement of pain symptoms, generalized symptoms, delay in recurrence from lymph nodes or metastatic foci, treatment of non-surgical staging of cancer, and addition of surgical intervention. No increase in survival, liver, heart and kidney toxicity should be used with caution in the elderly.

PLF:

5-FU: 2600mg / m2 IV for 24 hours, once a week for 6 weeks Contraindications: pregnant women, leukocytes <2,500 / mm

Cisplatin: 50mg / m2 / IV for 15 minutes weeks 1, 3, 5 and 8.

Calcium folinate 500 mg / m2 intravenously for 30 minutes once a week for 6 weeks.

FAMtx:

Methotrexate 1500mg / m2 infusion 30 minutes at 60 minutes break on day 1 

5-FU: 1500mg / m2 infusion in 30 minutes, day 1.

Calcium folinate 15mg / m2 infusion within 24 hours after methotrexate infusion on day 2, from day 2 on, infusion for 6 hours.

Doxorubicin: 30mg / m2 infusion in 30 minutes, repeated on the 15th and 29th.

The drug has many side effects such as nausea, fever, diarrhoea, esophagitis, myelosuppression, agranulocytosis, myocardial toxicity, alopecia, and urticaria.

Radiotherapy:

Use 1 dose of 28-35Gy directly at the bottom of the tumour during surgery, or on the cut surface during surgery.

Using a dose of 45-50Gy, 20-30 times in combination with chemotherapy for inoperable cases with a bad prognosis (peritoneal metastases, bone, deep lymph nodes), or with surgery will reduce pain and delay tumour recurrence and limit metastasis.

Surgical treatment results: According to JRSGC:

Adverse: T1, T2, dredged lymph nodes far from the lesion area, no liver or peritoneum metastases have been found. The 5-year survival rate is 50%.

Relative: T1, T2, not metastasis, lymph nodes near the affected area. The 5-year survival rate is 25%.

Relative no treatment: T3, large, extensive, liver, peritoneal metastasis. Five-year survival rate was 15%.

No treatment for adversity: When the tumour is too large, the tumour is in stage T4N1, T4N2, there are more than 4 lymph nodes detected during surgery (2%).

Other supportive measures:

Iron supplementation, use of common painkillers, morphine and its derivatives.

Treatment of stomach lymphoma and other types of stomach cancers

Gastric lymphoma:

Stage1: Partial or full cut with chemotherapy and radiotherapy after surgery: 4 doses of CHOP, a combination of one or two doses of radiation therapy 39, 6Gy. Success 80%. If it is MALT lymphoma, the combination is to eradicate HP.

Stage 2, 3, 4: Surgery with chemotherapy, spread type not more than 2 years.

If no surgery is possible: Chemistry and radiotherapy: 4 doses of CHOP with radiation therapy 25, 5Gy on the upper half of the abdomen.

Follow-up for postoperative recurrence: Gastroscopy within the first 3 years, pay attention to Waldeyer lymphatic rings because this is the site or recurrence.

The outcome of treatment: Life for> 5 years is 50%

Smooth muscle sarcoma:

Malignancy is derived from muscle. Damage to the stomach stem, causing ulcers and bleeding. It rarely penetrates nearby organs and does not spread to the lymph nodes but can spread to the liver and lungs.

Surgical treatment combined with chemotherapy for metastatic cases

The carcinoid of the day:

This is the type of endocrine tumour that produces substances with many biological activities. Lesions are usually in the submucosal layer but can be ulcerated to the muscle layer. Lesions in many places with increased blood gastrin.

Treatment with surgery, chemotherapy plus Octreotide can improve symptoms in many patients.

Other mesenchymal tumours:

Malignancy originates in nerve tissue.

Treatment is mainly with surgery.

Kaposi vascular sarcoma:

Mainly in the skin, internal organs, especially the stomach.

Common in AIDS patients or in patients on immunosuppressive therapy.

Surgical treatment, the prognosis is very bad.

Secondary gastric tumour:

Treatment with chemotherapy, poor prognosis.