Rise of HER2 Positive Breast Cancer in India
As per the report by the Indian Council of Medical Research, 1,62,468 new cases and 87,090 deaths related to breast cancer were reported last year. It is estimated that India has the third-largest number of cancer cases amongst women in the world, after China and the US. The report also stated that breast cancer is the most common type of cancer in Indian women. These numbers have been significantly increasing since the past decade along with the mortality rates.
Breast cancer is a clinically heterogeneous disease in which gene and pathway function alter with genetic and epigenetic changes. It has varied morphology, molecular features, behavior, and response to therapy. Based on the gene expression profile, breast cancer is classified into ER-positive (luminal A and B) and ER-negative (basal-like, HER2 positive and normal-like). The HER2‐positive subtype is more aggressive, has a high propensity for early metastases, relapse and shorter survival rates as compared to other subtypes.
Today, many experts would agree with the fact that it is important to understand the subtypes of cancer, how they respond differently to different treatments, and how it can impact the survival rates. Personalizing the treatment and tailoring it as per the genetic and molecular characteristics of the patient could bring a huge breakthrough in cracking the right treatment. However, clinical decision making is challenging in current circumstances as most studies on breast cancer are based on western populations and additional evidence is required from studies on the Indian population. Real-world clinical data can offer new possibilities to assess the impact of new medical interventions in clinical care settings.
THB, India’s leading clinical intelligence company for personalized care and syndicated insights, conducted a survival analysis in the Indian population. Clinical big data repository was used just for HER2 receptor, irrespective of any other factor(s). The following insights were observed:
Causes of HER2-positive
There are a number of reasons that may explain the aggressiveness of HER2-positive as compared to HER2-negative including, but not limited to stages at diagnosis, size and grade of tumour, lymph node involvement, ER/PR status, overall health, smoker, non-smoker, response to therapy, historical report, age, financial health, socio-economic status, etc. Multiple factors must be analyzed to understand the survival path of a patient.
Testing the accuracy of HER2
The medical practitioners need to accurately identify the sub-type of the disease. Studies have highlighted that some HER2 status test results may be wrong as different labs have different criteria to assess HER2 status. The test results can sometimes be borderline — not strongly HER2-positive or negative. Also, tissue tested from one area can test HER2-positive and tissue from another area can test HER2-negative. Inaccurate lab results may lead to inaccurate diagnosis and treatment.
More awareness and more screening
As they say, a problem is half solved when identified at the right time. Likewise, the number of breast cancer deaths too can be reduced when women are more conscious about their health and timely check-ups. Experts suggest that women with a family history of breast cancer should start their screening mammogram 10 years before the index case.
India has a high burden of breast cancer as people are unaware of the disease until someone close to them suffers from it. When healthcare is not your top priority, screening becomes an ‘alien' word. Women with breast cancer go for screening only when they are symptomatic. On average, most 'symptomatic' cancers are stage 2B and beyond (significant numbers in stages 3 and 4). Because of this, breast cancer patients in India have lower survival rates.
In the west, more than 75% of breast cancer incidents are detected when it is present in early stages 1 and 2, resulting in good survival rates. Whereas in India, patients are diagnosed at later stages, when the disease is in a more advanced stage. Hence, survival rates are lower than in the west. India needs an aggressive promotion of screening and awareness as well as accuracy/precision in diagnosis and treatment. Lastly, women should be made more aware of the signs and symptoms of breast cancer and be encouraged to go for breast cancer screening.
Real-world evidence from tumour-specific models
Real-world data (RWD) from the electronic health records can be leveraged to create robust genomic and molecular models to not only inform clinicians but also to improve prognostic factors and treatment outcomes. THB can empower precision medicine interventions in oncology by distilling real-world evidence (RWE) from tumour-specific RWD models. This RWE generated has the potential to discover clinical breakthroughs from novel therapies, support oncology research, expand indications, accelerate regulatory approvals, track post-marketing safety, and provide more value to the drug pipeline.
