Cancer of the gastroesophageal adenocarcinoma (GEA) type is a complex and serious form of cancer. It can start in the stomach and work its way down to the lower part of the esophagus. A number of factors must be taken into account when deciding on the course of treatment for a patient with GEA. An accurate diagnosis of the patient’s cancer must be made, an understanding of the tumor must be gained, and the patient’s total health must be assessed. For the patient with HER2+ GEA cancer, the process of planning the First-Line treatment can be complex and requires the coordination of the testing for the cancer’s biomarkers and the multifaceted team of health care professionals who are involved in the patient’s total care.
In the complex process of treatment planning for first-line HER2+ GEA cancer, more than one biomarker has to be tested and considered by the oncology specialist in charge of the patient together with pathologists and radiologists and with the help of specialist nurses, dietitians and other members of the multidisciplinary team of health care professionals involved in the cancer treatment process.
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Understanding the Role of Biomarker Testing
Biomarkers are characteristics of cancer cells and their surrounding environment that may influence a particular treatment’s efficacy. In the case of HER2-positive GEA, the HER2 protein is involved in the growth, division and survival of cells. Tumors with increased levels of HER2 protein, as indicated by a positive IHC score, or those in which there is an amplification of the HER2 gene (detected by ISH) may benefit from HER2-directed treatment for eligible patients.
Typically HER2 status is determined by means of Immunohistochemistry (IHC) and if indicated by IHC also by means of In-Situ Hybridization (ISH) to measure copy number of the HER2 gene. The amount of HER2 protein expressed by cancer cells and number of copies of the HER2 gene in tumor cells are measured and compared with normal cells to determine a score to determine if the tumor is HER2-positive according to clinical criteria.
Getting the right biomarker information is crucial for the choosing the treatment and interpreting results from tests. Results from tests need to be accurate and reviewed by a pathologist and discussed with the treating oncologist. Samples for testing can at times be inadequate or unclear and further testing or review of existing tissue may be required.
Evaluating Additional Biomarkers
While HER2 status is the primary factor that is taken into account for the choice of treatment for patients with HER2-positive GEA, other biomarkers also can influence the clinical choices of the treating physician. PD-L1, dMMR and MSI are examples of such other biomarkers that can be tested for in addition to HER2 status.
However, in addition to the HER2 status of a patient’s tumor other biomarkers may be important to establish the tumor’s biological profile and to select an appropriate treatment for the patient. Other biomarkers like the expression of PD-L1, dMMR-status or MSI-status can be important in specific situations and in line with clinical evidence.
In terms of the testing of additional biomarkers, it is essential to ensure that all relevant tests are performed and that results are interpreted. In many cases, the pathologist will work with the treating oncologist to ensure that all necessary tests are performed, and results are interpreted for the treating clinician. Where tests are inconclusive, further testing may be performed on the same sample or alternative samples considered.
The Importance of Multidisciplinary Collaboration
Multidisciplinary care is provided by a team of health care professionals who are specialists in their respective fields. Cancer care for patients with GEA benefits from the complex combination of diagnostic and treatment-related data from a team of different specialists.
The Oncologist outlines the appropriate treatment for the patient’s cancer and discusses the benefits and potential problems of the treatment with patients. The Pathologist provides information on the type of cancer and the patient’s tumors, and the Radiologist tells patients about the images taken of their tumors to assess the extent of spread of their cancer and to check on them at subsequent assessments.
Dietitians and other supportive care professionals can play a role in assessing a patient’s nutrition needs, tackling issues with weight loss, reduced appetite, problems with swallowing food and any emotional problems that may affect a patient’s ability to complete their treatment or return to good health.
Coordinating First-Line Treatment Decisions
The consideration of factors for planning the first-line treatment of HER2+ GEA takes into account the tumor biomarker information in conjunction with other clinical features of the cancer, the patient’s GEA and general health, the tumor site, the patient’s performance status, and their general medical history. Other medical conditions that the patient may have, current medication, and the patient’s nutritional status can also influence the suitability of certain treatments.
When appropriate, First-Line HER2+ GEA treatment could be provided as HER2-directed therapies in conjunction with other systemic treatments. In discussing appropriate treatment options for patients with GEA, the team reviews the clinical evidence to ensure the chosen First-Line treatment is most suitable for individual patients.
There are many people involved in a diagnosis of cancer and this means that often information is given at different times. Therefore, it is important that all the people involved are able to communicate with each other to make sure that all the relevant information has been considered.
The healthcare professionals will set up the appropriate monitoring program considering possible adverse effects of the chosen treatment and the specific health risks of the patient. Patients should be provided with information of the reasons for their treatment, of the follow-up schedule, and of the symptoms they should report without delay.
Supporting Shared Decision-Making
Patients are major participants in the decisions to be made about their cancer care. Patients must be informed of the diagnostic findings, the treatment options available and the benefits and potential problems associated with each of the options. In this way patients are able to ask questions and express any of their concerns prior to planning their treatment.
These priorities can often vary between patients and a discussion around them with the patient’s priorities being the main driver for the clinician’s recommendations allows for the appropriate treatment to be recommended for that individual. Involving family members or carers (if required by the patient) to the consultation can also be helpful to support the patient’s understanding of the cancer and the treatment, as well as to plan practical ways to manage the consequences of cancer and its treatment.
Conclusion
Coordinating the biomarker testing with the multidisciplinary cancer care is crucial in planning the treatment option for a patient with HER2-positive GEA. Accurate diagnostic information, collective expertise of all health care professionals and individual clinical circumstances of each patient are key to making suitable treatment recommendations for patients with cancer.
An individualized approach to treatment of patients with HER2-positive GEA can be achieved using clinical evidence to inform Shared Decision Making with the patient and their family and support the patient through their treatment and its side effects. Continued communication between all involved and regular review and re-reference to clinical evidence as needed will allow for the right treatment strategy to manage the disease and the patient’s needs throughout their illness.
Disclaimer: The information provided in this article is intended for educational purposes only and should not be interpreted as medical advice, a clinical guideline, or a recommendation for any specific treatment.
