Computer simulation determines how much drug is harmless © Getty

In recent times, clinicians have fallen back on mathematics to go around the severe side effects of chemotherapy on cancer patients. They have devised a drug application strategy called metronomic chemotherapy (MCT), which releases anti-cancer drugs in smaller, harmless doses.

However, several studies have cautioned of the risks of toxicity in MCT in the long run. Now, a new mathematical model and on-screen simulation study1 promises better understanding of the toxicity profile of cancer drugs for MCT.

The simulation study helps determine the frequency and timing of the cancer drugs that do not shoot up the toxicity level in the patient’s body. In the interaction between cancer cells and drugs, toxicity is produced by the drug deposition or drug burden (DB) as also by the accumulation of dead cells and metabolites secreted by the growing tumour cells. All the toxic chemicals thus generated are excreted by the body and this is measured in terms of clearance rate (CR).

The researchers ran simulation studies using an initial tumour load of 40 million drug sensitive cells and 10 million drug resistant cells. The study found that if the kidney function deteriorates regularly in a cancer patient, he or she needs therapy to improve removal of toxic chemicals. This could lead to better drug application decisions. With low drug retention, when the CR is high, toxicity does not reach a severe stage without the need of drug withdrawal.

"From the simulation studies, the model looks apt for a given clinical setting," says Durjoy Majumder, lead researcher.

The model has considered the patho-physiological constraints of cancer that vary among populations according to food habits, lifestyles, height, and weight. This opens up the possibility of tailor-made medicine.