Targeted therapy for gastrointestinal cancer
Targeted therapy for gastrointestinal cancer is a type of cancer treatment that acts on specific proteins, genes, or other molecular features involved in cancer growth and spread. Unlike conventional chemotherapy, which affects many rapidly dividing cells, targeted medicines are designed to interfere with particular processes that help cancer cells survive or multiply. Their suitability depends on the type of cancer and the molecular characteristics of the tumour.
Gastrointestinal cancers include cancers of the stomach, colon, rectum, oesophagus, pancreas, liver, and biliary tract. Targeted therapy is not appropriate for every patient with these cancers. Doctors may recommend specialised biomarker testing to determine whether a tumour has a feature that can be treated with a particular medicine.
What Is Targeted Therapy for Gastrointestinal Cancer?
Targeted therapy uses medicines designed to act on specific molecular targets involved in cancer development. These targets may help cancer cells grow, divide, repair damage, or form blood vessels that supply a tumour.
Some targeted medicines block signals that tell cancer cells to grow. Others interfere with proteins involved in cell survival or reduce the formation of new blood vessels that feed a tumour.
The treatment differs from one cancer to another because gastrointestinal cancers do not all share the same molecular features. Two people with the same type of cancer may have different biomarker results and may therefore have different treatment options.
Targeted therapy may be used alone or in combination with chemotherapy, immunotherapy, or other treatments when appropriate. The choice depends on the diagnosis, cancer stage, test results, previous treatment, and the patient’s overall health.
How Does Targeted Therapy Work?
Cancer cells can develop changes in their genes or proteins that help them grow and survive. These changes may create specific targets for treatment.
Targeted medicines work in different ways, including:
Blocking growth signals: Some medicines interrupt signals that encourage cancer cells to multiply.
Targeting specific proteins: Certain drugs act on proteins that are unusually active or present in greater amounts in some tumours.
Reducing blood vessel formation: Some medicines interfere with signals that help tumours develop a blood supply.
Blocking abnormal molecular pathways: Certain drugs target pathways that cancer cells rely on to grow or survive.
The effect of a targeted medicine depends on whether the cancer has the relevant target and whether the medicine is suitable for that particular diagnosis. A medicine that works for one molecular subtype may not work for another.
Which Gastrointestinal Cancers May Be Treated With Targeted Therapy?
Targeted medicines are available for selected gastrointestinal cancers. Their use depends on the cancer type, stage, biomarker results, and current treatment recommendations.
1. Colorectal Cancer
Some colorectal cancers have molecular features that help guide targeted treatment. Testing may examine changes in genes such as KRAS, NRAS, and BRAF, along with other relevant markers.
For selected patients, treatment may target particular growth-signalling pathways or tumour blood vessel formation. Some treatment decisions also depend on the tumour’s location and whether certain gene changes are present.
Not every patient with colorectal cancer benefits from the same targeted medicine. Biomarker results help identify which options may be appropriate.
2. Stomach and Gastroesophageal Junction Cancer
Some stomach and gastroesophageal junction cancers have specific molecular features that may make targeted treatment an option. Testing may include HER2, and other biomarkers may be relevant depending on the clinical situation.
For patients whose tumours have an appropriate target, a targeted medicine may be considered as part of a treatment plan. The choice depends on the test findings, stage of disease, previous treatment, and other medical factors.
3. Oesophageal Cancer
Treatment options for oesophageal cancer depend on the tumour’s location, cell type, stage, and molecular characteristics. Targeted therapy may be relevant in selected cases, particularly when the cancer falls within a group for which an appropriate targeted medicine is available.
Not all oesophageal cancers have an actionable target, so testing and specialist assessment are important when deciding whether this treatment approach is suitable.
4. Biliary Tract Cancer
Some bile duct and other biliary tract cancers have molecular changes that can be matched with specific treatments. Depending on the diagnosis, testing may identify alterations involving FGFR2 or other clinically relevant targets.
These findings may help guide treatment decisions, especially when the cancer is advanced or has progressed after previous treatment. The availability and suitability of a medicine depend on the exact alteration and current treatment guidance.
5. Pancreatic Cancer
Most pancreatic cancers are not treated with targeted medicines in the same way as some colorectal or stomach cancers. However, selected patients may have specific molecular changes that open up additional treatment options.
Depending on the circumstances, testing may look for inherited or tumour-related changes such as BRCA1 or BRCA2, as well as other uncommon actionable alterations. These results may help guide treatment discussions and decisions.
6. Liver Cancer
The term liver cancer includes different diseases with different treatment approaches. Targeted medicines are used in certain cases of hepatocellular carcinoma, the most common primary liver cancer, particularly when systemic treatment is required.
The choice of treatment depends on factors such as liver function, the extent of the cancer, general health, and other clinical considerations. Treatment options may include targeted medicines, immunotherapy, or other approaches depending on the individual case.
What Is Biomarker Testing, and Why Is It Important?
Biomarker testing looks for particular genes, proteins, or other features in cancer cells that may help guide treatment. It can be especially important when considering targeted therapy for gastrointestinal cancer.
Testing may be performed on tumour tissue obtained during a biopsy or surgery. In some situations, blood-based tests may also provide useful information.
The tests recommended depend on the type of cancer. They may include:
HER2 testing: May help identify certain stomach or gastroesophageal cancers that could respond to HER2-directed treatment.
RAS testing: KRAS and NRAS results help guide the use of certain targeted medicines in colorectal cancer.
BRAF testing: May identify a molecular alteration relevant to treatment in selected cancers.
MSI or mismatch repair testing: Helps identify tumours with particular DNA repair features that may influence immunotherapy decisions.
Other molecular tests: Depending on the cancer, testing may examine alterations such as FGFR2, NTRK, or BRCA-related changes.
Not every patient needs every test. The oncology team determines which biomarkers are relevant based on the cancer diagnosis and the treatment decisions being considered.
A positive result does not automatically mean that a targeted medicine is suitable. The specific alteration, cancer type, stage, previous treatments, and approved or available treatment options all matter.
What Are the Benefits of Targeted Therapy?
For patients whose cancers have an appropriate molecular target, targeted therapy may offer an additional treatment option. Potential benefits vary by medicine and cancer type.
Possible advantages include:
More specific treatment: The medicine is designed to act on a particular molecular target or pathway.
Additional options: Targeted therapy may be available when a tumour has a feature that can be matched with a treatment.
Combination approaches: Some targeted medicines can be used with chemotherapy or other treatments when supported by clinical evidence.
Treatment guided by tumour biology: Biomarker results can help clinicians select among available options.
However, targeted therapy is not guaranteed to work. Cancer cells can sometimes develop resistance, and the benefit varies from person to person. Some targeted medicines can also cause significant side effects. The expected benefits and risks should be discussed before treatment begins.
What Are the Possible Side Effects?
Targeted therapy does not have one universal side-effect profile. The effects depend on the medicine, the molecular pathway it affects, the dose, and the patient’s health.
Possible side effects include:
Skin rash or dry skin
Diarrhoea or other digestive changes
Fatigue
High blood pressure with certain medicines
Changes in liver function
Mouth irritation
Infusion-related reactions with some treatments
Effects on wound healing or bleeding risk with certain medicines
Some side effects may be mild, while others require prompt medical attention or a change in treatment. Patients should report new or worsening symptoms rather than waiting for the next scheduled appointment.
The treatment team may recommend blood tests, blood pressure checks, skin care, or other monitoring based on the medicine being used. Patients should seek urgent medical advice for severe breathing difficulty, signs of a serious allergic reaction, uncontrolled bleeding, or other severe symptoms.
Targeted Therapy vs Chemotherapy
Targeted therapy and chemotherapy both aim to control cancer, but they work differently.
| Feature | Targeted therapy | Chemotherapy |
|---|---|---|
| Main approach | Acts on specific molecular targets or pathways | Interferes with processes involved in cell growth and division |
| Treatment selection | Often depends on biomarker or molecular findings | Depends on cancer type, stage, and treatment plan |
| Side effects | Vary according to the target and medicine | Vary according to the drugs and their effects on healthy cells |
| Use with other treatments | May be combined with chemotherapy or other treatments | May be combined with targeted therapy, radiotherapy, or other treatments |
| Suitability | Only appropriate when supported by the cancer’s features and clinical evidence | Appropriate for many cancers, but not every patient or situation |
Neither treatment is automatically better than the other. In some cases, chemotherapy remains the main treatment. In others, targeted therapy may provide an important option. Some patients receive both as part of a planned combination.
Can Targeted Therapy Be Combined With Immunotherapy?
In selected situations, targeted therapy may be used alongside immunotherapy or other cancer treatments. These medicines work through different mechanisms, and combining them may be appropriate for particular cancer types or treatment settings.
Immunotherapy helps the immune system recognise or attack cancer cells, while targeted therapy acts on specific molecular targets or pathways. The decision to combine treatments depends on clinical evidence, tumour characteristics, potential side effects, and the patient’s overall health.
A combination is not suitable for every gastrointestinal cancer. The oncology team considers the expected benefits and risks before recommending a particular regimen.
How Is the Response to Targeted Therapy Monitored?
Monitoring helps determine whether the treatment is working and whether side effects are manageable. The follow-up plan depends on the cancer type and the medicine prescribed.
It may include:
Reviewing symptoms: Changes in pain, appetite, bowel habits, energy, or other symptoms may help guide assessment.
Blood tests: These can monitor blood counts, liver function, kidney function, or other measures relevant to the medicine.
Imaging scans: CT, MRI, or other appropriate scans may be used to assess changes in the tumour.
Specific monitoring: Some medicines require checks such as blood pressure measurement or heart-function assessment.
Reviewing treatment response: Results help determine whether treatment should continue, be adjusted, or be changed.
If the cancer progresses despite treatment, further assessment may be needed to understand whether resistance has developed or whether another treatment option is appropriate.
Who May Be Eligible for Targeted Therapy?
Eligibility depends on more than the name of the cancer. A treatment may be considered when the tumour has a relevant target and there is evidence that the medicine can help in that clinical setting.
The assessment may consider:
The exact type and stage of gastrointestinal cancer
Biomarker and molecular testing results
Previous cancer treatments and the response to them
Liver and kidney function, and other health conditions
Possible interactions with current medicines
The likely benefits, risks, availability, and cost of treatment
Patients can ask whether biomarker testing is recommended for their diagnosis and how the results may affect their treatment options. It is also reasonable to ask about alternative treatments, expected monitoring, side effects, and practical considerations before making a decision.
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Frequently Asked Questions
Targeted therapy uses medicines that act on specific proteins, genes, or molecular pathways involved in cancer growth. It may be considered when a gastrointestinal tumour has a relevant target and the treatment is appropriate for that diagnosis.
Targeted therapy may be an option for selected colorectal, stomach, liver, pancreatic, and biliary tract cancers. Its suitability depends on the cancer type, stage, molecular features, and available treatment evidence.
Biomarker testing identifies certain genes, proteins, or molecular changes in a tumour. These results can help determine whether a specific targeted medicine may be suitable for the patient's cancer.
Targeted therapy acts on particular molecular targets or pathways involved in cancer growth. Chemotherapy interferes with processes involved in cell growth and division. The choice depends on the cancer diagnosis, treatment goals, and relevant test results.
Side effects vary by medicine and may include skin rash, diarrhoea, fatigue, high blood pressure, changes in liver function, or infusion-related reactions. Patients should report new or worsening symptoms to their treatment team.
The outcome depends on the cancer type, stage, molecular features, and response to treatment. Targeted therapy may help control cancer in selected situations, but it cannot be expected to cure every gastrointestinal cancer.
Yes. Certain targeted medicines may be combined with chemotherapy or other treatments when clinical evidence supports the approach. The appropriate combination depends on the cancer type, molecular findings, and the patient's health.
Monitoring may involve symptom reviews, blood tests, imaging scans, and medicine-specific checks. The results help the oncology team assess whether the treatment is working and whether any changes are needed.
No. Targeted therapy is suitable only in specific clinical situations. The decision depends on the cancer's molecular features, stage, previous treatments, overall health, and whether an appropriate medicine is available.
If the cancer progresses, the treatment team may reassess the disease, review test results, or consider additional testing. Depending on the findings, other targeted medicines, chemotherapy, immunotherapy, or alternative treatment approaches may be considered.