Dr. Moushumi Suryavanshi 

M.D (Pathology), Ph.D. (Cellular & Molecular Oncology)

Senior Consultant Molecular Diagnostics 

Rajiv Gandhi Cancer Institute & Research Center Delhi, India

        The field of molecular has arisen from the convergence of work by geneticists, physicists, and structural chemists. Historically it began with the geneticist finding it difficult to analyze beyond Mendel’s laws of segregation and independent assortment, the actual mechanisms of gene reproduction, mutation, and expression. This gave birth to the term “molecular biology” in the year 1938 by Warren Weaver, then the director of the Natural Sciences Section of the Rockefeller Foundation. This new branch of science began to uncover many secrets concerning the ultimate units of the living cell….in which delicate modern techniques are being used to investigate ever more minute details of certain life processes (quoted in Olby 1994: 442). This branch has grown from just being “Molecular” to “Genomics”.

Molecular Diagnostics in Oncology is low-hanging fruit in the field of Genomics. Cancers occur whenever there is an abnormality at the genetic level which leads to uncontrolled growth of cells. These molecular aberrations are detected by special Molecular Tools. Molecular diagnostic tests can be used to select a cancer therapy and/or to monitor the effects of a treatment based on characteristics of or changes in the biomarker. This approach has revolutionized cancer diagnosis and treatment. It has replaced conventional chemotherapy in many cancer types.  Many patients are matched to a Molecular therapy based on the genomic profile. Lung cancer is one such cancer whose treatment including the quality of life of patients has been radically altered by these targeted or precision therapies. There are a number of predictive Molecular tests involving either the analysis of individual drug targets or identification of specific tumor phenotype, which aid the choice of anticancer drugs. Molecular diagnostics also provide biomarkers to include patients for the new age Immunotherapy which harness the patient’s immune system to destroy the cancer cells.

 There are several other major avenues in cancer medicine, which utilize molecular-based assays. Testing for hereditary cancer syndromes is now routinely used both for the identification of persons at-risk and for personalization of systemic treatment.

A liquid biopsy is a liquid biomarker that can be isolated from body fluids, such as blood, saliva, urine, ascitic fluid, or pleural fluid. The armamentarium of liquid biopsy practically comprises Circulating tumor cells (CTC) and Circulating tumor DNA (ctDNA). This can be used to detect primary and secondary genetic abnormalities to tailor treatment in cancer patients without the need for a tissue biopsy in multiple scenarios. Monitoring of malignant disease can also be achieved through molecularly-driven detection of residual tumor fragments. It is anticipated that liquid biopsy will serve as an instrument for early cancer diagnosis and screening in the near future.

This information is for general guidance and reflects the opinions and experience of the author. It is not intended to replace specialist consultation or provide treatment advice for specific cases.

Leave a Reply

Your email address will not be published.