How Biomarker Testing Helps Guide HER2-Positive Stomach Cancer Treatment

How Biomarker Testing Is Shaping Decisions About HER2 Positive Stomach Cancer Treatment

Biomarkers have become important tools in helping to understand cancer better than by knowing where it is and how far it has spread.

Biomarker tests can tell the oncologist about the biology of the cancer in patients with stomach cancer and aid in the choice of the best treatment for individual patients.

Stomach cancer, also known as gastric cancer, starts in the stomach lining and is increasingly common in western countries.

Gastric cancer, also known as stomach cancer, is a cancer that originates in the stomach or in the lining of the stomach.

Most decisions regarding the treatment of a patient with stomach cancer are based on the size and location of the primary tumor as well as the extent of cancer spread (stage).

In addition, a patient’s general health as well as medical history can also be factors in treatment choices for a patient with stomach cancer.

However, a deeper understanding of the tumor can provide additional information to help a patient and their family decide on the best course of action and to help a patient’s oncologist to make the best treatment decisions for his or her patient.

Understanding Biomarkers in Stomach Cancer

Biomarkers are cellular, tissue or other eventually, biological sample characteristics that can be measured.

A protein, alteration in a gene or change in the expression of genes can be used to measure and characterize a disease.

The results from a biomarker test can help a cancer patient’s and their family members to better understand their disease and to help the cancer patient’s physician to decide on the best treatment for a patient’s cancer.

Depending on the test results, your oncologist will decide which patients might benefit from certain cancer treatments and which patients may not get any relief from other treatments.

The biomarker test can be used in conjunction with other cancer tests.

Most of the biomarkers for stomach cancer are studied in the context of the disease’s stage, the patient’s medical history, and the variety of approved and experimental treatments for the cancer.

Often the studies focus on patients with advanced or metastasizing gastric cancer who are being considered for systemic therapy with conventional chemotherapy or for targeted or immunotherapeutic approaches.

Why HER2 Testing Matters

HER2, stands for human epidermal growth factor receptor 2.

This protein is involved in the normal growth of cells. In some cancer cells, like gastric cancer, there is an overactivity of this protein due to changes in the HER2 gene leading to an overproduction of the HER2 protein in cancer cells.

This type of gastric cancer is referred to as HER2-positive.

The HER2 status of a patient’s tumor can tell their oncologist if the patient is a candidate for HER2-targeted medications.

HER2-targeted medications work to reverse processes that help cancer cells grow.

Most tests for HER2 status use a tumor tissue sample.

They measure the amount of the HER2 protein on cancer cells, or they look for an excess copy number of the HER2 gene.

These test results are interpreted by experienced pathologists using established criteria for classification.

It is essential to point out that all stomach cancers are not HER2 positive and having this biomarker detected does not mean that a particular treatment will be recommended for the whole course of the cancer.

All other factors such as the stage of the cancer, previous treatment(s), patient’s general health and other findings from investigations into the patient’s cancer would be taken into account by the oncology team.

How Biomarker Results Influence Treatment Decisions

The results of biomarker tests can be used by a patient’s oncologist to choose a cancer treatment that is more likely to be effective.

For example, in some cases patients with advanced or metastatic, HER2 positive gastric cancer can be treated with trastuzumab, sometimes in combination with chemotherapy, in suitable clinical circumstances.

By knowing what to expect when it comes to the issues related to your her2 positive stomach cancer treatment, you will be able to help your oncology team choose the best treatment options based on the many factors that contribute to a patient’s overall treatment plan.

Additional information from biomarker testing can influence selection of further treatment(s) by a physician and/or their cancer treatment team.

In some instances, a variety of systemic anticancer therapies can be considered for patients with stomach cancer depending on a number of factors, including the patient’s clinical situation and from what cancer treatment recommendations are derived from clinical evidence.

Other Biomarkers That May Be Relevant

Some other biomarkers which may be of value for gastric cancer include the measurement of the expression of PD-L1 by immunohistochemistry.

While information on this marker is becoming more widely available and being used to aid in the selection of patients for immunotherapy for other cancer types, its use is still in its infancy for gastric cancer.

Another important biomarker for gastric cancer is PD-L1. Its expression in tumor cells can influence the use of certain immunotherapies.

Just like for HER2, interpretation of PD-L1 results is largely method-dependent and must be considered in conjunction with the tumor’s characteristics and the intended treatment.

Because cancers with deficient mismatch repair are immunogenic and may be responsive to immunotherapy, testing for these defects and associated increases in microsatellite instability (MSI) is also important for selecting patients for consideration of certain therapies.

Depending on the stage of cancer, the therapies available and the clinical guidelines that apply, there are additional biomarkers which can be of value to decide on the optimal cancer therapy.

A patient together with their oncologist can decide on which additional tests are of value and how the results of these tests can influence cancer treatment.

Understanding the Testing Process

Most tumor biomarker tests are run on the tissues removed during a cancer patient’s surgery or a biopsy (tested to see if there is cancer).

There are different types of biomarker tests that are run on a biopsy or on removed tissues to look for specific proteins in cancer cells or genetic mutations in cancer cells.

In some instances the amount of tumor tissue from a biopsy may not be sufficient to test for all the relevant biomarkers and further tissue may be required.

It may also take some time to receive the results from the biomarker testing and this will depend on the type of testing done and the laboratory that is doing the test.

Patients may want to know if the tissue from their existing biopsy can be tested for additional biomarkers, how long it will take to receive results, and how the results from biomarker testing can influence treatment decisions.

The patient should retain a copy of the pathology report and test results as they would for any other medical treatment and consult these documents when the patient sees other health care providers for other medical problems including other cancers.

Discussing Biomarker Results With the Oncology Team

Reporting Test Results & Their Significance

In addition to identifying potential alternative therapies for the cancer, patients and families should ask whether the cancer has been tested for relevant biomarkers and whether additional testing is required.

Patients and families should also ask about the potential side effects of proposed treatments and the expected monitoring and response to therapy for patients on these medications.

One thing to keep in mind is that biomarker testing is part of a larger array of factors that will determine the best course of treatment for individual patients with cancer.

Thus, while a patient’s physical health, prior treatments, and treatment goals all will figure into decisions regarding his or her care, biomarker test results will guide the oncologist and other health care providers in choosing among various different options for treatment.

Moving Toward More Individualized Cancer Care

Biomarker testing in gastric cancer has allowed us to gather more information about the tumor and to tailor the treatment of stomach cancer based on the molecular characteristics of the individual cancer.

Understand the purpose of tests for you and your family’s information and in order to have better discussions with your oncologist.

Work with your oncologist to translate test results into the most appropriate treatment for your individual circumstances.