Treatment Drugs for Stomach Cancers

If you have stomach (or gastric) cancer and are discussing treatment options with your cancer care team, you may be recommended certain types of anticancer drugs based on your condition. This would entail knowing what drugs to take, when to take them and their dosage. All this information can be a lot to take in if you don’t know what to expect. Learning about the various drugs used in gastric cancer treatment and understanding how they work will be very helpful in preparing you for this stage in your cancer journey.

This page is a compiled list of the individual drugs and common drug combinations used in the treatment of gastric cancers, namely gastric adenocarcinomas, gastrointestinal stromal tumors (GISTs) of the stomach and gastric neuroendocrine tumors (NETs).

Chemotherapy drugs

When cells grow and divide to form new cells, they go through a series of phases called the cell cycle, during which the cells will copy their genetic material (DNA). Chemotherapy is a type of treatment that uses cancer-killing drugs to interfere with DNA and the cell cycle, thereby stopping the uncontrolled growth of cancer cells and killing them.

Apart from gastric adenocarcinomas, chemotherapeutic agents are also used to treat gastric neuroendocrine cancers (NECs), which are rapidly-growing NETs. They can be classified according to the class of drugs they belong to, which include:

• Alkylating agents: For adenocarcinomas, cisplatin, carboplatin and oxaliplatin are commonly used. For gastric NECs, on top of these three alkylating agents, streptozocin, dacarbazine and temozolomide are also used.
• Antimetabolites: 5-fluorouracil (5-FU), capecitabine and trifluridine/tipiracil combination pill can be used to treat gastric adenocarcinomas and gastric NECs.
• Antitumor antibiotics: epirubicin and doxorubicin are anthracyclines used to treat gastric adenocarcinomas and gastric NECs respectively.
• Mitotic inhibitors: docetaxel and paclitaxel are two mitotic inhibitors that are commonly used to treat gastric adenocarcinomas.
• Topoisomerase inhibitors: irinotecan and etoposide can be used to treat both gastric adenocarcinomas and gastric NECs.

Some of these drugs are administered together in what is known as a chemotherapy drug combination. While different drug combinations are used in the treatment of gastric adenocarcinomas and gastric NECs, common combinations across these two types of gastric cancers include:

• FOLFIRI: leucovorin, 5-FU and irinotecan
• FOLFOX: leucovorin, 5-FU and oxaliplatin
• XELOX: capecitabine and oxaliplatin

Targeted therapy drugs

Targeted therapy is a type of cancer treatment that uses drugs specifically designed to identify and attack cancer cells while limiting damage to healthy cells. It does this by targeting the specific genes, proteins and tissue environments that are unique to cancer cells and play a vital role in their uncontrolled growth and survival. This effectively interferes with and stops the cancer’s growth and spread within the body.

Thus far, there are only three targeted therapy drugs approved for the treatment of gastric adenocarcinomas. They are trastuzumab, ramucirumab and fam-trastuzumab deruxtecan.

Targeted drugs used in the treatment of GISTs are known as tyrosine kinase inhibitors (TKIs). These drugs target proteins called tyrosine kinases, which are responsible for sending signals that promote cellular processes that encourage cancer progression. TKIs that are most commonly used to treat stomach GISTs are imatinib, sunitinib, regorafenib, ripretinib and avapritinib.

In terms of treating gastric NETs, there is only one targeted drug therapy approved for use: everolimus. Everolimus works by targeting a protein called mechanistic target of rapamycin (mTOR), which is hyperactive in many cancers. This hyperactivity results in cancer-promoting effects, like tumor angiogenesis and the uncontrolled growth of cancer cells. By blocking the activity of mTOR in the cancerous neuroendocrine cells, everolimus is thus able to slow tumor growth.

Immunotherapy drugs

Immunotherapy is a type of cancer treatment that works by boosting the ability of your immune system to identify and attack cancer cells, thereby strengthening your body’s immune response to cancer.

The use of immunotherapy agents in gastric cancer is still fairly new and thus far, only two have been approved to treat gastric adenocarcinomas: nivolumab and pembrolizumab. Both belong to a class of drugs called immune checkpoint inhibitors (ICIs), which block checkpoint proteins that turn off your body’s immune response and thus stop your immune system from killing cancer cells.

Interferon therapy is a type of immunotherapy used occasionally in the treatment of metastatic gastric NETs to slow the growth of tumors and treat the symptoms of carcinoid syndrome. It uses a drug called interferon alpha-2b (IFNα2b), which can boost your immune response and destroy cancer cells directly.

Hormone therapy

Hormone therapy is a type of cancer treatment that slows or stops the growth of NETs and reduces the levels of circulating hormones. It uses drugs called somatostatin analogs (SSAs), which mimic the action of a natural hormone called somatostatin that controls the release of other hormones such as gastrin, insulin and serotonin. Two SSAs that are used as first-line treatment for carcinoid syndrome and unresectable, metastatic gastric NETs are octreotide and lanreotide.

Peptide receptor radionuclide therapy (PRRT)

PRRT is a type of internal radiation therapy that destroys NETs with a small but powerful radioactive dose. It uses radioactive drugs called radiopeptides or radiopharmaceuticals, which can deliver radiation to the tumor directly. The most widely used radiopeptide in PRRT is called 177Lu-DOTATATE, also known by its commercial name Lutathera®.

While there are many different drugs and medications that can be used for gastric cancers, finding the type of cancer treatment and drug regimen that is best suited for you plays a very important part in the success of your treatment journey. Therefore, please consult your doctors and cancer care team to discuss which treatment options work best for you.