Stomach cancer ( gastric carcinoma ) is the second most common type of cancer in the world (about 800,000 new cases and 650,000 deaths per year; 7.8% of all malignancies; male: female ratio 2: 1) with areas of high incidence represented by Asia, Eastern and Central Europe and South America. The mortality rate in Italy is around 5-10 cases per 100,000 inhabitants.
The predisposing factors are manifold:
- Cigarette smoke;
- a diet with a high intake of red meat, smoked and salted foods and low in fruit and vegetables;
- Helicobacter Pylori infection, which induces a series of histological changes that precede the development of gastric cancer such as chronic gastritis, intestinal metaplasia, atrophy and dysplasia.
Therefore, primary prevention of gastric cancer could potentially be possible through diet, encouraging high-risk populations to decrease the consumption of smoked meats, sausages and foods preserved with salt and to increase the consumption of fruit and vegetables. Prevention can also be done through the eradication of H. pylori infection, particularly in childhood and adolescence.
The most frequent site of onset is the anthro-pyloric (distal) region, although in recent years in Europe and the USA there has been a high incidence of cardiac malignancies and of the esophagus-gastric (proximal) junction.
Macroscopically gastric carcinoma is divided into initial forms (Early Gastric Cancer in its PenA variants, which shows both a higher frequency of lymph node metastases than other EGCs and a worse survival, and PenB) confined to the mucosa and submucosa, and in advanced forms , classified by Borrmann as polypoid (type I), exophytic / fungiform (type II), ulcerated (type III) and diffusely infiltrating (type IV).
Microscopically it is characterized by a wide intratumoral heterogeneity and it is not uncommon to observe cases in which different cytological and architectural aspects coexist. The WHO classification foresees 4 most frequent histological types: tubular, papillary, mucinous, ring-cell carcinoma with bezel as well as some rare variants (hepatoid carcinoma, carcinoma with lymphoid stroma, chorioncarcinoma, adenosquamous, squamous, undifferentiated and small cell carcinoma) . Lauren’s classification has found great diffusion and application, above all for its simplicity. It distinguishes two main types of carcinoma, that of “intestinal type” and “diffuse”. Neoplasms that have both aspects are classified as “mixed type”.
The gastric carcinoma spreads mainly to adjacent organs (such as the pancreas, duodenum, esophagus, transverse colon, peritoneum), via lymphatics with invasion of regional and estraregionali lymph node stations or even at a distance the tumor site, and via blood more frequently to the liver, lungs.
Symptomsthey are vague and nonspecific, usually underestimated for a long time or treated as “gastritis” or benign ulcer: the most common are weight loss, epigastric pain, nausea, anorexia, anemia, sometimes dysphagia (for cardiac tumors and the esophagus-gastric junction) early satiety and sarcophobia (repulsion for meat). Symptoms can be absent until the tumor reaches such a size as to give stenosis or bleeding. Clinical manifestations of metastatic extension are the appearance of abdominal pain, the increase in liver volume, the appearance of ascites, jaundice and palpable lymph nodes (those in the left supraclavicular region are identified as the “Troiser sign”). Sometimes,
Diagnosis and staging
The diagnostic gold standard for stomach cancer is undoubtedly represented by Esophagogastroduodenoscopy (EGDS) which allows, in addition to a direct view of the bowel, also the possibility of performing biopsy specimens necessary to make histological diagnosis.
Additional diagnostic imaging methods for the diagnosis, staging and follow-up of gastric cancer are X-ray of the digestive tract (less and less used after the diffusion of endoscopy), ultrasound with or without contrast medium, Chest and abdomen CT with contrast medium, ecoendoscopy and diagnostic laparoscopy.
Circulating biomarkers (CEA, CA 19.9, AFP, BHCG) play a marginal role in the diagnosis of stomach cancer, while they are more reliable in post-operative monitoring (follow-up) providing more precise information on the clinical course or more timely on the presence of a relapse, in order to select the optimal therapeutic treatment.
The tumor is staged using the TNM classification, which describes the anatomical extent of the lesion (T) at the time of diagnosis and after therapy, the presence or absence of loco-regional lymph nodes (N) and metastases (M).
There is talk of neoadjuvant or preoperative chemotherapy when it precedes surgery and adjuvant chemotherapy if it is performed after surgery (it aims to reduce the risk of local recurrence or the appearance of distant metastases). Chemotherapy associations include platinum salts (cisplatin or oxaliplatin) and fluoropyrimidines (fluorouracil, capecitabine), anthracyclines (epiadriamycin) and, when used preoperatively, they are able to obtain a partial or complete pathological response on the primary tumor and on the lymph nodes, increasing the possibilities to obtain surgical radicality. When the disease has advanced both locally and remotely (liver, lungs, lymph nodes, peritoneum, bone) chemotherapy represents the only therapeutic weapon capable of obtaining control of the disease. Among the new molecules active in advanced gastric cancer are antiangiogenic drugs. Chemotherapeutics are typically administered intravenously and in some cases in tablets and their administration occurs through treatment cycles with variable cadence.
The interventions that can be carried out in gastric cancer surgery are divided into exeresis interventions, with an understanding of radicality in the oncological sense, and palliative interventions, which may be exeresis or derivative. In some cases, however, even palliation is not feasible and the intervention is limited to exploration only. In the case of single metastases or infiltration of single contiguous organs, the possibility of a metastasectomy and a resection of the infiltrated organ portion (liver, transverse colon, mesocolon, pancreas, spleen, anterior abdominal wall) can be evaluated.
Based on the localization of the tumor, we distinguish 3 types of surgical interventions : upper or lower polar resection, subtotal gastrectomy and total gastrectomy associated with lymphadenectomyD1, D2 or D3 (i.e. with the removal of retro and perigastric lymphatic tissues located along the major vascular trunks and in border areas such as duodenum, pancreas, hepatic ilus and upper mesentery). The intervention can be further expanded with the exeresis of other contiguous viscera that were eventually affected by the neoplasm (enlarged total gastrectomy). This includes en-bloc resection of the stomach, about 2 cm of esophagus and duodenum, body and tail of the pancreas and spleen with epiploon; in this case the lymphadenectomy is conducted up to the hepatic, gastroduodenal, preaortic and renal chains. An enlarged D3 lymphadenectomy is always practiced in Japan. This also for EGC, where the N3, N4 lymph nodes are positive in 1%. There is currently no common orientation in the rest of the world.
The operation is completed by restoring intestinal continuity through multiple techniques, among which the most used are gastro-jejunal reconstruction according to Billroth II with “omega” handle or according to Roux (the latter useful to avoid complications typical of Billroth II such as biliary duodeno-gastric reflux gastritis) with a latero-lateral entero-enteroanastomosis with “Y” loop.
The surgical approach can be traditional (or laparotomic) or laparoscopic or minimally invasive. The use of laparoscopy in gastric carcinoma is a well-established technique for intra-operative staging as it is possible to highlight the loco-regional extension of the neoplasm and the possible presence of distant metastases or peritoneal carcinosis. Depending on the intraoperative finding, it will be decided whether to continue laparotomy with a curative resection or simply with a palliation. As far as laparoscopy is concerned in the treatment of gastric cancer, the scientific world is at the beginning of the experience and has not yet found a consolidated space. Numerous studies have been published demonstrating technical feasibility,
An improvement in the regional control of locally advanced gastric neoplasia can be achieved through the use of intra-peritoneal chemo-hypertemia once the exeresis of a gastric heteroplasia infiltrating the serous is carried out, or in the presence of peri-gastric carcinosis, or in the case of a positive peritoneal cytology, ascertained during the surgical exeresis of the neoplasm or during a pre-operative staging laparoscopy. The drugs commonly used for chemohyperthermia are represented by Cisplatin (25 mg / l / m2) and Mitomycin C (3.3 mg / l / m2) at a temperature of about 42 degrees for 60 minutes.
The complications of surgery can be manifold: intraoperative (contusion or rupture of spleen or liver, vascular lesions, lesion of the biliary tract or transverse mesolon) and early postoperative (fistula and anastomotic dehiscence, anastomotic stenosis, hemorrhages, pancreatitis, the formation of hematomas, empyema or abscesses, ischemia and necrosis of the pedunculated loops) or late (dumping syndrome, incoercible diarrhea and mechanical ileum, afferent loop syndrome, gastritis or esophagitis from biliary reflux, Total gastrectomy syndrome with malabsorption of VIT B12, folic acid, VIT D and iron and consequent anemia, weight loss, osteomalacia and osteoporosis).