KOLKATA: The little white headache pill that costs less than Rs 1.5 per tablet could catalyse one of the biggest breakthroughs in cancer treatment. A study by researchers in Kolkata says aspirin may not only block the growth of cancer cells but also give a lifeline to Stage IV patients by making them respond to chemotherapy.

The study, by the Institute of Post-Graduate Medical Education and Research (IPGMER) and Bose Institute, has tasted success on animals and even human tissues. Aspirin is being researched the world over as a low-cost preventive for many types of GI cancers, but the Kolkata study takes it a few steps higher -to prove its potential in combating malignant cells. The research team has proved that it can shrink cancer stem cells -the principal cause of the disease and the reason behind its spread -and turn them ‘chemo-sensitive’, or reactive to chemo. The finding, which holds out hope for 1.5 lakh chemo-resistant patients in the country, is in the human trial stage.

IPGMER started the study in 2010 to explore aspirin’s preventive role, but the aim took new dimensions as the research progressed. It’s now in its fourth and final phase. The initial studies, held on breast cancer patients, revealed that the pill indeed checked the proliferation of cancerous cells. This was seen in 80% of the patients in the study. “At this juncture, we came to know that Bose Institute, too, was working to establish a link between aspirin and chemo-sensitivity. Since we were working on the same lines, we decided to merge our studies,” said Diptendra Sarkar, head of the department of breast cancer, IPGMER. A joint research took off and the results left the research team stunned. An analysis of cancerous cells and tissues revealed that aspirin indeed altered the nature of cancer stem cells and made them respond to chemotherapy.

“Cancer stem cells are responsible for the disease. Chemotherapy that kills cancer cells fails to eliminate these highly resistant cancer stem cells. They proliferate and turn more aggressive. Often, they hide in tissues and cause a relapse, spreading the disease to other parts of the body. Aspirin inhibits chemotherapy-induced increase in cancer stem cells and sensitizes them to chemotherapy by decreasing the levels of resistance-giving proteins in these cells.

Therefore, although aspirin itself cannot kill cancer stem cells, but it can make chemotherapy effective and check the spread of the disease in the body,” said Tanya Das, senior professor at Bose Institute, who led the study on behalf of the institute.

Though the research is based largely on screening of breast cancer patients, researchers believe it holds true for all forms of cancer, though each has a different stem cell type. “We got early indications of this dramatic finding when we screened 1,200 patients on aspirin. Only one had cancer, so we compared it to a screening of an equal number of breast cancer patients who had not had aspirin. So, it was statistically proved that aspirin did help to prevent the disease. Later, we confirmed the finding through an analysis of human tissues, which showed that it did help to check cancerous tumours by blocking the Cox 2 receptor gene,” said Sarkar.

Almost all terminal stage cancer patients turn resistant to chemotherapy in eight-nine months, say experts. “After five-six cycles, chemotherapy doesn’t yield any result for these patients. So, aspirin might help. If it makes the therapy effective, then the rate of survival is bound to go up,” said Sarkar.

Oncologist Gautam Muk hopadhyay called for more research on the long-term impact of aspirin.