Cancer remains one of the top causes of deaths in the Philippines. Four Filipino cancer patients die every hour, which totals to 96 patients succumbing to the disease every day, according to the University of the Philippines’ Institute of Human Genetics, National Institutes of Health.
But a novel cancer treatment is renewing hope of survival for patients who are otherwise terminally ill.
In his lecture during the 19th Mid-Year Convention of the Philippine Society of Oncologists, Dr. Marcelo Imasa, medical oncologist at St. Luke’s Medical Center, explained the science behind immuno-oncology as a cancer treatment option.
He said cancer grows and thrives because of its ability to hide from the immune system and immuno-oncology prevents this mechanism from taking place.
“When the tumor cells express a high population of protein biomarker called PD-L1 (programmed cell death ligand-1), then the T-Cell, a type of white blood cell that has a key role in immune response, becomes inactive,” said Dr. Imasa. “This is because the PD-L1 can combine with another protein PD-1. Their interaction prevents T-Cells from attacking what it perceives as non-harmful cells or non-cancer cells in the body.”
Dr. Imasa continued, “To overcome such an immune escape mechanism, what we do is try to block the interaction of PD-L1 and PD-1.”
“Immuno-oncology drugs are able to do this. When there is no interaction, there is no inhibitory effect now presented by the tumor cell to the T-Cell. The T-cell can then recognize and attack the cancer cells.”
Through immuno-oncology, the immune system is strengthened to be able to target and eliminate cancer cells that have been evading immune attack. “Its side effects are also manageable,” added Dr. Imasa.
Dr. Imasa also discussed how immuno-oncology has improved outcomes for some of his patients with stage 4 lung cancer.
“When you say stage 4 lung cancer, we’re talking of survival in months, probably a year. But this patient went through immuno-oncology and targeted therapy. She’s been alive for two years now and doing well. In her last evaluation, there’s no evidence of disease. No evidence of the cancer. This is one of the good results that have come out of immuno-oncology.”
Another speaker during the event, Dr. Jasper Andal, molecular pathologist and quality assurance officer at St. Luke’s Hospital, reiterated the indications for immuno-oncology and how it is opening up new pathways on how cancer can be fought and eventually beaten.
“In lung cancer, immuno-oncology can be used as first line of treatment, depending on the expression of PD-L1,” he said. “The approved indication for cancers with Microsatellite Instability (MSI)-high and mismatch repair (MMR)-deficient solid tumors is really groundbreaking as well. All solid tumors that are MSI-high are candidates for immuno-oncology, regardless of where they are located in the body.”
In the Philippines, immuno-oncology is approved by the Food and Drug Administration as treatment option for non-small cell lung cancer, Hodgkin lymphoma, melanoma, head and neck, bladder, and gastric cancers. Studies are being conducted to further look into the efficacy of immuno-oncology on cervical cancer and other types of cancers.
The National Integrated Cancer Control Act plays a critical role in making the supportive care system more inclusive for indigent cancer patients, which includes making immuno-oncology more reachable as treatment option.
