MOLECULAR-LEVEL targeted therapy is often used for personalised cancer treatment, with or without hormonal therapy and chemotherapy, says Dr Mithua Ghosh, Director, Clinical Diagnostics, at Strand Life Sciences. For instance, HER-2 protein is found in excess on the surface of some types of cancer cells. Specialists think this may cause them to grow and spread more quickly. So, targeted medications such as trastuzumab are used to treat conditions (especially certain breast and stomach cancers) that overexpress HER-2. Although targeted therapy is known to improve survival rates in certain types of cancer – lung, renal, breast, colorectal, liver, thyroid and melanoma, for instance – long-term survival or a complete cure remains elusive, says Dr Ghosh. The answer may lie in further understanding and evaluating the biology of cancer and the subsequent treatment based on accurate measurements of contributory factors via DNA-sequencing technologies. Targeted deep-sequencing of a large number of patients suffering from different types of cancer will help analyse mutation profiles of tumours and provide better insights into individuals’ cancer triggers. The tests available for this range from small gene panels of actionable hotspot mutations to clinical/whole exome sequencing and whole genome sequencing.