Impact of prognostic tests in the treatment of early-stage breast cancer

Dr Alpesh Kikani, Medical Oncologist, Shashwat Haemato-Onco Associates, Rajkot explains that breast cancer patients who are diagnosed at an early stage can take help of a prognostic test to understand the disease better and get personalised treatment.

Globally, in 2020, there were 6.85 million deaths due to breast cancer, according to a report by WHO (World Health Organisation). Approximately 1 in 4 cancer cases in women worldwide are breast cancers. Breast cancer is the most frequent cancer among women and the leading cause for mortality.

Breast cancer is diagnosed in India every four minutes and is fatal every 13 minutes. The incidence of this cancer is highest among Indian women.

Early detection and treatment of breast cancer result in high survival rates. In many low and middle-income countries, including India, almost 50 per cent of breast cancer cases are diagnosed at an advanced stage (Stage 3 or 4). It is more difficult to treat diseases diagnosed at these stages, and they are usually incurable. Depending on its type, breast cancer can be aggressive or non-aggressive. TNBC (Triple Negative Breast Cancer) and HER2+/neu are more aggressive compared to ER+/HER2-/neu breast cancer which is relatively less aggressive.

If diagnosed at an early stage, patients with ER+/HER2-/neu breast cancer have a positive prognosis. Most patients with early-stage HR+/HER2- breast cancer do not benefit from chemotherapy, as has been observed and well documented in the literature. The standard hormonal or chemotherapy treatments may not work equally for all patients. Prognosis for each patient receiving standard therapy is different. Typically, the clinicians gauge the prognosis of patients based on clinical factors such as tumor size, tumor grade, age of the patient, no.of +ve nodes and Ki-67 status, ER, PR etc. Chemotherapy affects both physical and mental health of the patient undergoing treatment. Chemotherapy is given to target the fast-growing cancer cells. However, along with cancer cells, it also destroys healthy cells, mostly the fast growing cells, causing side effects in the patients.

A prognostic test predicts the response to a standard treatment that is given to treat a disease thereby predicting a patient’s likelihood of developing a disease or experiencing a future medical event. Breast cancer prognostic tests analyse certain biomarkers within a patient’s body such as specific genes, patterns of gene expression, or protein biomarkers that can assess the risk of recurrence. With the use of a prognostic test in breast cancer patients, especially in HR+/HER2-  disease, patients could avoid non-beneficial and ineffective chemotherapy. The prognostic tests identify the patient who would derive benefit from chemotherapy.

Early detection of breast cancer can save a patient from aggressive treatments such as chemotherapy  especially in ER+/HER2/neu negative patients and can lead to a better “quality of life” for the patient.

Breast cancer patients who are diagnosed at an early stage can take help of a prognostic test to understand the disease better and get personalised treatment. Prognostic tests assess the risk of recurrence of cancer for individual patient and enables the doctors to personalise treatment for everyone, resulting in improved quality of life and better clinical outcomes.

In certain cases, the patients may be identified as having lower chances of relapse of cancer based on clinical parameters or other prognostic markers like Ki67 as judged by the oncologist, which may not be accurate in defining how the cancer could behave in the future. The benefit of the prognostic test is that it identifies the patient with higher chances of recurrence based on the characteristics of the cancer which further helps in optimizing the treatment for each patient. This approach makes sure that the patients are not under-treated or over-treated and saves patients from the risk of recurrences in the future.

According to major international cancer treatment guidelines such as NCCN((National Comprehensive Cancer Network), prognostic tests are an essential part of breast cancer treatment. .

Despite the wide variety of prognostic tests available, not all of them have been proven to be useful or clinically useful for Indian patients. An Indian option ‘CanAssist Breast’ has been validated on Indian patients. CanAssist Breast is a prognostic test developed by OncoStem Diagnostics that classifies the patients as ‘low-risk’ or ‘high-risk’ based on the patient’s risk of breast cancer recurrence over five years. Tests like this provide information about the risk of recurrence of early-stage, hormone receptor-positive breast cancer patients. It analyses critical biomarkers in the tumour to assess the risk of recurrence and helps oncologists to personalise treatment plans. The test uses a proteomics- based method and an artificial intelligence-based algorithm to analyse a patented combination of protein biomarkers from the patient’s tumour to compute the risk of recurrence of cancer. The test result allows breast cancer patients who are classified as ‘low-risk’ to potentially avoid chemotherapy and its side effects.

Seeking the help of a prognostic test has proven to enable an oncologist with in-depth information related to breast cancers allowing them to take an informed decision and deliver better outcomes. Patients, on the other hand, can safely skip chemotherapy helping them to lead a normal life post cancer treatment.