What are the Symptoms and Signs of Stomach Cancer?
The most common symptom of stomach cancer is upper abdominal discomfort or pain. Also, weight loss is seen in the majority of patients.
Loss of appetite, early satiety and vomiting is also a common symptom.
Less commonly we may see an abdominal mass or distention, or jaundice due to the local extension or distant spread to other abdominal structures.
Rarely; a distant spread of the tumor may present as nodules near the umbilicus, or in the neck.
Anyone or combination of these symptoms is highly suspicious for stomach cancer, especially when it is present in a person with risk factors for disease.
What are the Investigations for Diagnosis and Staging of Stomach Cancer?
Most important investigation to confirm the diagnosis of stomach cancer is upper GI endoscopy, which also helps us to take a biopsy and do endoscopic ultrasound.
Once the diagnosis is confirmed, imaging help us to assess the spread of the tumor to local sites and distant metastasis.
In some cases, laproscopy may be required to explore the spread of disease into the peritoneum and other parts of abdomen.
Upper GI endoscopy is the first and the most important test to be done, when we are suspecting a patient to have stomach cancer.
As we have discussed previously, it help us to take a biopsy from the mass.
And also to do a endoscopic ultrasound, to look for the depth of the infiltration of the tumor into the esophageal wall and the local structures, and to look for the involvement of regional lymph nodes.
Once the diagnosis of the stomach cancer is confirmed, the next step is to do a CT scan of the abdomen and preferably thorax, to look for local extension and distant spread of the tumor.
PET CT scan may also be done rarely.
Sometimes, the tumor spread to peritoneum or abdominal structures may not be diagnosed accurately on imaging.
So laproscopic exploration of the abdomen and collection of peritoneal fluid for cytology may be required.
So these were the investigations required to confirm the diagnosis of stomach cancer and stage the disease.
What is the Normal Anatomy of Stomach?
What is the TNM Staging of Stomach Cancer?
Now, after discussing the different layers of the stomach wall, let’s discuss the T-staging of the stomach cancer.
First is the Tis or carcinoma in situ. This is not considered as malignant and is localized to the epithelium.
Infiltration of lamina propria or muscularis mucosa is called as T1a disease.
Infiltration into the submucosa is called as T1b. Muscularis propria infiltration is called as T2.
Infiltration of subserosa is called as T3. And infiltration of the tumor into the serosa is called as T4a disease.
When the tumor extends through the stomach walls to involve the adjacent structures it is called as T4b.
In this figure, the tumor extends to involve the colon.
And here it infiltrates the pancreas.
And here the tumor infiltrates into the spleen.
And here it invades the kidney.
It may also infiltrate into the liver or the diaphragm.
Now next comes the N staging or the nodal staging.
The regional nodes which drain the stomach are different in different part of the stomach.
These nodes drain the lesser curvature of the stomach.
And these drain the upper part of the greater curvature of the stomach.
And these the lower part.
These nodes drain the pyloric antrum.
All the nodes draining the different part of the stomach, ultimately drain into these nodes which are called the coeliac nodes.
Depending on the number of regional lymph nodes involved, it can be divided into different N stages.
N0 – No regional lymph node involved by tumor.
N1 – Cancer has spread to 1 or 2 regional lymph nodes.
N2 – Cancer has spread to 3 to 6 regional lymph nodes.
N3a – Cancer has spread to 3 to 6 regional lymph nodes.
N3b – Cancer spread to >/=6 regional lymph nodes.
M0 – Cancer has not spread to non-regional lymphj nodes and/or distant organs.
M1 – Cancer that has spread to the distant important organs such as lungs, bones, and brain
Distant metastasis may be seen to the liver.
The peritoneum in form of multiple peritoneal deposits.
To the lungs in form of multiple nodular deposits.
Rarely, it may spread to the left supraclavicular lymph node which presents as nodular deposits in the left side of the neck.
Or a nodular deposit in the periumbilical region called as sister Mary Joseph Nodule.
It may also present as pelvic deposits in the rectovesical pouch or pouch of Douglas.
Or as nodular deposits in one or both the ovaries, called as Krukenberg’s tumor.
Very rarely, it may also spread to brain or bones.
The stomach cancer treatment mainly depends on the stage, location of the tumor, performance status of the patient, the presence of certain genetic abnormalities, along with other factors.
Treatment of Localised and Locally Advanced Stomach Cancer
As you can see in the figure, only the superficial cancerous portion is removed, while the remaining tissue remains unaffected.
Removal of the stomach is all an option for early stage disease, but is practiced less commonly.
Then comes the T1b disease which infiltrates upto the submucosa.
Gastrectomy is the preferred treatment for T1b disease.
Then comes the T2 disease which extends up to the muscular propria.
And T3, which infiltrates the subserosal tissue. And lastly, T4a which infiltrates the serosa.
Form T2a and T4a, surgery may not be sufficient and may not be possible in many cases, so a combination of chemotherapy, radiation therapy, and surgery may be required.
CancerBro, how is it decided what combination of modalities is to be used?
It is decided by the oncologist on an individual patient basis, depending upon the exact stage of disease, performance status and comorbidities of the patient.
Now lets come to the treatment of the T4b disease, in which the tumor extends through the wall of the stomach to involve adjacent structures.
In this figure, the tumor infiltrates into the large intestine.
tumor infiltrates into the large intestine
And here, it invades the pancreas.
And here it extends into the spleen.
Here it infiltrates into the kidney.
It may also extend into the liver or diaphragm.
Surgery may not be possible in all cases of T4b disease, so in such cases, chemotherapy with or without radiation therapy may be used.
Whereas, if the tumor is surgically resectable, multimodality treatment with surgery, with or without chemotherapy or radiation therapy is used
In T4b disease also, the decision to move ahead with surgery, or treat the disease with chemotherapy or radiation therapy is taken by the oncologist on an individual patient basis, depending upon the exact stage of the disease, performance status and the comorbidities of the patient. That is the treatment for non-metastatic stomach cancer.
Surgery for Stage I Stomach Cancer
Endoscopic mucosal resection (EMR)
- Indications include
- Well differentiated
- Type IIa or IIc
- Confined to mucosa
- Complications include
- Bleeding ~ 3%
- Perforation ~ 3%
- Complete resectability ~ 73%
Intragastric mucosal resection
- Endoscopy+ laparoscopy
- Uses three balloon trocar plased in the Gastric lumen
- Indications similar to EMR
- Resection is done laparoscopically
- Results and complications similar to EMR
Laproscopic Wedge Resection
- Indications similar to EMR
- Minimally invasive
- Sufficient margin
- Detailed HPR
- Minimal complication
- Limitation – cannot be used for lesion in lesser curvature, near Cardia, and Pylorus
- Indications include
- Poorly dif. Intramucosal lesion
- Submucosal extension
- Pts who cannot be treated by EMR or by limited surgery
Surgery for Stage II and Stage III Disease
- Principles underlying a potentially curable resection are
- Appropriate resection with adequate free margin
- Adequate regional lymph node clearance corresponding to the location of the primary tumor
- Safe and well functioning reconstruction
- Absolute curative resection: may be deemed when
- There is no peritoneal or hepatic metastasis
- Serosa not involved by tumor
- Resection margins free histologically
- Total vs Subtotal Gastrectomy
- Initially total gastrectomy was preferred
- It was associated with increased duration of surgery, increased risk of complication and impaired nutritional status.
- Therefore subtotal gastrectomy was done for distal tumors, and found to be safe and effective provided adequate margins was given.
- Recommended Margins
- Proximally – 3cm for Intestinal type, 5cm for Diffuse type
- Distally at least 2cm of uninvolved duodenum
- Total gastrectomy is deemed necessary-
- When adequate proximal margin is not possible
- When tumor involves 2 or more sectors of the stomach
- Diffuse carcinoma (Borman 4)
Treatment of Metastatic Stomach Cancer
Now we come to the treatment of metastatic disease.
It may present as metastasis to the liver or peritoneum or lungs, one or both the ovaries.
It may also present as pelvic deposits in rectovesical pouch or pouch of Douglas.
Or involvement of left supraclavicular lymph node, presenting as swelling in the left side of the neck.
Or as a nodule in the periumbilical region, called as Sister Mary Joesph module.
Very rarely, it may present as metastasis to brain or bones. In all these cases of metastatic disease, chemotherapy and/or targeted therapy is the mainstay of treatment.
But other modalities like surgery, radiation therapy or bone-directed therapy may be used for palliation or relief of symptoms.
Always remember that the treatment for metastatic disease is not generally curative, so the intent of the treatment is prolongation of life, reduction of symptoms and improvement of the quality of life.
Systemic therapy agents that are effective in Stomach Cancer Treatment are-