Stomach cancer is a malignant neoplasm of certain cells in the stomach. In 95 per cent of cases, the glandular cells that produce gastric juice are affected (adenocarcinoma). Very rarely, lymphatic cells (lymphoma) or cells of muscle or connective tissue (sarcoma) degenerate.

The causes for the development of gastric carcinoma are still unclear in detail.

Chronic alcohol and nicotine consumption, chronic Helicobacter pylori infection and dietary habits, such as the consumption of smoked or salted foods containing nitrates, are considered exogenous (caused by external factors) risk factors.

Endogenous risk factors are adenomatous gastric polyps (1-2% of all polypoid gastric mucosal lesions), chronic atrophic gastritis (inflammation of the gastric mucosa) type A (pernicious anaemia), Menetrier's disease (giant fold gastritis), gastric ulcers, previous stomach surgery and genetic factors (blood group A, familial gastric carcinomas).

Symptoms of gastric carcinoma usually only occur in the advanced stages of the disease in the form of uncharacteristic upper abdominal complaints (loss of appetite, feeling of fullness, bad breath, vomiting, stomach pain, etc.), as well as weight loss and poor performance or symptoms of gastric bleeding (tarry stools = black stools, vomiting blood).

Medical history and physical examination

During a detailed consultation, you told the doctor about all your symptoms and previous illnesses (including family hereditary diseases). A detailed physical examination was also carried out.

Laboratory

By analysing your blood, we obtain information about your general condition and certain organ functions. Frequent changes affect the blood count, for example, as the red blood pigment haemoglobin may be reduced due to chronic blood loss from the tumour.

Tumour markers are only of secondary importance in gastric tumours and are only used in patients who present for follow-up care after complete surgical removal of the tumour

Gastroscopy (gastroscopy/endosonography)

In instrumental diagnostics, gastroscopy is considered the cornerstone of diagnostics, in which histological confirmation should be achieved by means of 5-10 biopsies (tissue samples). The accuracy of this method is 97-98% with 6-10 biopsies. In addition, the examiner should precisely describe the localisation and extent of the process. Endosonography (ultrasound via endoscopy device) performed during the same examination provides important information regarding the depth of penetration of the tumour (assignment to the T category) and any regional lymph node enlargement.

Upper abdominal sonography

In the diagnosis of spread (staging), it is essential to perform an ultrasound of the abdomen including the small pelvis to detect abdominal fluid, metastases (liver, in women Krukenberg tumour = ovarian metastases) and infiltration into surrounding organs.

X-ray thorax in 2 planes

As part of the staging process, a radiological chest x-ray can be used to diagnose distant metastases, particularly in the lung area.

Computed tomography

Depending on the location of the tumour, computer tomography provides information about possible metastases of the tumour in other organs or lymph nodes. As with ultrasound, however, it is often not possible to visualise smaller tumours. The disadvantage is a certain exposure to radiation.

Laparoscopy (laparoscopy)

If the tumour is at an advanced stage (T3/4), a diagnostic laparoscopy should be performed to rule out distant metastases, e.g. in the peritoneum, liver or ovary, before planned chemotherapy prior to surgery (neoadjuvant therapy).

Skeletal scintigraphy (bone scintigraphy)

By administering a radioactive substance intravenously (via a vein), an accumulation in bone metastases is achieved, which can be detected using a special camera.

Histological typing

The histological (fine tissue) classification of gastric carcinomas is generally based on the WHO (World Health Organisation). Over 90% of all malignant gastric tumours are adenocarcinomas (originating from gland-forming tissue). Almost all stomach tumours are made up of glandular cells (adenocarcinomas).

Tumour stage/classification

In order to determine the optimal therapy, the exact spread of the tumour must be determined in the form of the so-called TNM formula, which should result from the staging examinations. In addition to the exact determination of the anatomical extent of the tumour, the TNM classification guarantees a uniform classification of the various gastric carcinomas. Three different components are taken into account: The extent of the primary tumour (T), the absence or presence, as well as the extent of lymph node metastases (N), and the absence or presence of distant metastases (M).

Furthermore, the microscopic examination of the tumour tissue is necessary for the determination of the therapy concept in order to assess the malignancy. This involves a comparative assessment of the tumour cell with the original organ cell(grading = cell similarity).

Finally, the resection stage is determined postoperatively (after surgery), which provides information on the absence or presence of residual tumour.

As before, only radical resection (complete surgical removal of a diseased organ) of gastric carcinoma offers a chance of cure. Primary surgery should only be performed with the aim of achieving an R0 resection. It may make sense to first treat a gastric tumour with medication before surgery, as this can provide better results. An indication for palliative resection (palliative = disease-mitigating, without the aim of a cure) is given on a case-by-case basis and is justified by the occurrence of tumour complications (bleeding, passenger disorder). The results of the investigations into the spread and stage of the tumour determine the procedure here. Every case of a patient with a stomach tumour is discussed in our interdisciplinary tumour conference

• Surgical therapy

As a cure can only be achieved through complete resection, all patients for whom surgery appears possible must be presented to an experienced visceral surgeon.

• Radiotherapy

To date, there are no reliable data on postoperative (after surgery) radiotherapy. With palliative intent, radiotherapy in the cardiac area may be particularly useful for irresectable (inoperable) stenosing (narrowing) tumours. In individual cases, radiotherapy can also be used in combination with chemotherapy after surgery in the case of extensive lymph node involvement.

• Chemotherapy

Gastric carcinomas are tumours that can be treated with chemotherapy. Several substances are used here. Chemotherapy can be administered both before (neoadjuvant therapy) and after (adjuvant chemotherapy) a possible operation as well as in patients for whom the aim of therapy is not to cure but to contain the disease (palliative chemotherapy).

As with bowel cancer, antibodies have found their way into the treatment of gastric cancer. In tumours that show increased production (overexpression) of the surface protein HER2, chemotherapy can be improved with a HER2 antibody. For this reason, it is recommended to clarify the HER2 status of all gastric cancer patients before chemotherapy.

• Supportive therapy methods

These therapies are primarily based on the symptoms reported to us by the patient or serve to prevent imminent complications caused by the tumour.

The aims of supportive therapy for gastric carcinoma are

Ensuring adequate food intake/nutrition and pain relief

If a recurrence (recurrence of the tumour in the former tumour area) occurs, treatment should be repeated, although the restrictions on treatment described above also apply here.

The patient can eat and drink anything that is good for them and does not cause any discomfort. Patients usually have a poor tolerance for strongly flavoured foods and fatty foods. The daily requirement should be divided into at least 6 smaller meals throughout the day. Care should be taken to eat slowly and chew thoroughly.

If gastric emptying is delayed, as can occur after partial gastric resection, a trial with propulsants (metoclopramide, erythromycin) should be undertaken. If diarrhoea occurs as a result of fatty stools, the use of pancreatic enzyme preparations can improve fat absorption.

Particularly in gastrectomised patients, but often also in subtotally gastric resected patients, vitamin B12 supplementation (1,000 µg subcutaneously or intramuscularly every 3 months) should be given throughout the patient's life to prevent macrocytic anaemia or nervous deficits (funicular myelosis).

The prognosis of patients with gastric carcinoma is essentially determined by the tumour stage at the time of diagnosis and the extent of resection depending on this.