Stomach cancer: “Unfortunately, the diagnosis is often made at an advanced or metastatic stage”

– Why doctor: What does the term “digestive cancer” encompass?

Pr Jean-Baptiste Bachet : Digestive cancers represent all cancers that can occur within the digestive tract, which begins at the esophagus and ends at the anus, along with the stomach, duodenum, and small intestine. , colon and rectum. So, we can have cancers that affect these different areas, but also all the organs that are linked to the digestive tract: the pancreas, the liver, the gallbladder.

Esophageal cancer: “lifestyle changes” increase cases of “so-called proximal cancers”

What are the risk factors for stomach cancer?

Stomach cancer is one of the most common cancers worldwide. It has several particularities. First, in France and in Western countries, the incidence has decreased in recent years: we had around 8,500 cases per year in France in the 1980s and today we are around 6,500 cases per year. There is therefore a reduction in risk which can be explained epidemiologically by the evolution of risk factors. In fact, historically, we have a bacteria called Helicobacter pylori: it is a bacteria which is a carcinogen which can cause stomach cancer. Its presence in the stomach is totally linked to lifestyle and changes in hygiene. So the improvement in hygiene conditions in France and in Western countries has meant that we are less carriers of this bacteria, and as a result, we have fewer stomach cancers linked to it. This mainly gave rise to so-called distal stomach cancers, that is to say, which affect the distal part, the antrum and the body of the stomach.
At the same time, there is an increase in another type of stomach cancer which is linked this time to changes in lifestyle, particularly overweight and obesity, and which will promote the occurrence of reflux. gastroesophageal. Over time, this gastroesophageal reflux can lead to abnormalities and irritation. So we have an increase in cases of so-called proximal cancers which will affect either the lower esophagus or the cardia.

Lynch syndrome increases the risk of developing certain cancers

Besides poor lifestyle, do we know the genetic causes of stomach cancer?

There are rare genetic causes, in around 3% of cases. There are mainly two genetic syndromes which are responsible for stomach cancers of genetic origin. There is Lynch syndrome, which is a syndrome that will give rise to a whole spectrum of different cancers, including colorectal cancers as well. And then, we have a very particular syndrome, which is called hereditary diffuse gastric cancer syndrome. It is linked to a mutation in a gene which will promote the occurrence of cancer at a young age.

What symptoms can lead to diagnosis?

As there is no screening in France, diagnosis is more often made based on symptoms. You may have symptoms linked to the presence of the primary tumor in the stomach, therefore pain in the epigastric cavity. We can have complications such as hemorrhage, therefore bleeding which can reveal the presence of these tumors. If the tumors are high enough, we can also have blockages, what we call dysphagia, that is to say difficulty in getting food down, a feeling of blockage with potentially regurgitation. And then we can also have symptoms which are non-specific to the primary tumor, but which correspond to the evolution of the disease, since unfortunately, the diagnosis is often made at an advanced or metastatic stage. At this time, you may experience fatigue, slightly more diffuse pain, and a change in your general condition, which will lead to examinations and a diagnosis of cancer.

“For very small tumors, we can do surgical or endoscopic treatment alone”

What are the possible treatments ?

In terms of treatments, we differentiate two things. First, tumors that are localized, the goal of which is healing. For very small tumors, surgical or endoscopic treatment can be done alone. As soon as the tumors are a little larger, there will be preoperative treatment which is essentially based, in France, on chemotherapy two months before the operation. Then we perform the operation and do more chemotherapy. Or, we can do radiochemotherapy for proximal tumors, quite high, in the esophagus or cardia. So, in all cases, we do treatment before the operation as soon as the tumor has progressed a little.
For tumors which are not immediately operable, which are said to be locally advanced, for which there are contraindications to the operation, or for tumors which are metastatic, the treatment is based on chemotherapy in combination. with different types of treatments.
In recent years, many new treatments have arrived: we have notably had immunotherapy for a subgroup of stomach cancers for which we know that they will respond better, which allows a good percentage of cancers to of the stomach to benefit from it. This immunotherapy is combined with chemotherapy. Or, we have other types of treatments that are under development and which are targeted therapies, which we will also use in combination with chemotherapy. In the future, we will have to see if we can combine these targeted therapies in the event of a double alteration or not. Or to know if it is better to start with one therapy rather than another in patients who have double alterations… So there is a lot of work in perspective, a lot of new treatments arriving, and hope for our patients !

How is the support provided to patients?

Many things are done in France to support families. The national cancer institution offers a lot of information, there are also a lot of things that are done by the League against Cancer, which also provides support for patients. There are also associations that are created for genetic syndromes, associations for particular types of cancers… So there are quite a few things that are done, which vary depending on the region, depending on the center in which we are. supported. And for post-cancer too, that is to say once we have completed the entire therapeutic sequence. The goal is to cure patients after this treatment, so we also have a whole bunch of help to enable them to live with the potential after-effects of different surgeries, help with professional reintegration, etc.
What is also important is physical activity! We now have a lot of evidence to show that physical activity helps to better tolerate treatments, with fewer complications, both for medications and for surgery, and that it also helps strengthen the immune system. This activity is therefore important at all times during treatment and favored for our patients.

You can find the interview in images with Professor Jean-Baptiste Bachet, by scientific editor Juliette de Noiron (PhD):