At times, cancer patients can build up resistance to certain medications, leading to a relapse of the disease. Hence, it is critical to monitor the progression or regression of the illness constantly.
In a recent breakthrough, a team of Indian scientists, working with their collaborators, have shown how clusters of circulating tumour cells (CTCs) could help monitor the response to cancer treatments and predict a patient's survival chances. CTCs are nothing but the cancer cells that have sloughed off the tumour and are circulating in the blood.
"Assessing if a treatment is working for a patient is an extremely challenging area", says Prof Prashant Kumar, Faculty Scientist at the Institute of Bioinformatics, Bengaluru, who led the study told Research Matters.
In collaboration with his colleagues Ajay Balakrishnan and Dr Annapoorni Rangarajan from the Indian Institute of Sciences, Prof Kumar has proposed a method to quantify clusters of circulating tumour cells in cancer patients during different treatments.
Their study was published in the journal Scientific Reports and was funded by the Ministry of Science and Technology and Wellcome Trust-DBT India Alliance.
Often, doctors resort to periodic biopsies to monitor cancer. It is an invasive procedure, and most of the time, when the patient reaches the terminal stage, it is not advisable to collect tissue samples through a biopsy. Besides, not every patient can go through surgery, especially when the cancer is in advanced stages. Here is where "liquid biopsy" comes to the rescue.
In the proposed technique, the researchers used blood from the patient to predict the progression of cancer and the response of the treatment. "This method, called liquid biopsy, or simply a blood test, could be used for cancer diagnosis and treatment monitoring", explains Prof Kumar, who has been studying clusters of circulating tumour cells since 2013. "Here we are not isolating the CTCs or enriching them, but allowing them to grow in a natural microenvironment before testing them".
Based on how the cultured cells look, a doctor can assess whether a patient is responding to the treatment provided to him/her. Blood samples that contained tight clusters indicate patients who are not responding to the therapy. Thus, the technique can help them determine the best course of treatment.
The researchers, in collaboration with oncologists from Bengaluru’s Kidwai Memorial Institute of Oncology, validated their method by testing it on over 150 blood samples of patients suffering from one of four cancers – lung, breast, esophageal, or bladder cancer.
The test takes around a week to show the results and costs a fraction of most present-day tests. It can monitor how cancerous cells in the body would respond to the drugs in real-time.
In a country where roughly 1.2 million people succumb to cancer every year, it is incredible how a simple blood test could facilitate a better way to follow up with this disease.