Immunotherapy and targeted therapy give patients more options in the battle against cancer.
A gift from God. That is how Dr Ang Peng Tiam, the Medical Director of Parkway Cancer Centre, described the outcome for one patient.
Back in 2002, a man with cancer of the kidney came to see Dr Ang. By the time the cancer had been diagnosed, it had spread to his lungs and bones, and the tumour was pressing on his spinal cord. The outlook was grim.
Fortunately for the patient, there was a medication called interferon. This is a kind of protein naturally produced by white blood cells to fight infection. Interferon treatment is a manmade protein that is given to patients to stimulate the immune cells to fight cancer. It is part of a class of treatment known as immunotherapy.
“Not many patients respond to interferon, but if they do, they respond well,” said Dr Ang. This patient was one of those who responded well. He stuck with the treatment for eight years, then decided to stop. But the disease never came back – it was as if the patient’s immune system had stayed awake, said Dr Ang.
“Cancer of the kidney, Stage 4, and still alive after 13 years. It’s a miracle,” he said.
Dr Ang recounted this story at a seminar on Overcoming Cancer, organised by Channel NewsAsia and Parkway Cancer Centre in October at the Swissotel Merchant Court. The focus of the seminar was on using immunotherapy and targeted therapy to fight cancer.
At the seminar, various doctors from PCC spoke about the potential of these two treatments for lung, gastrointestinal, breast and blood cancers.
Targeted therapies block the growth and spread of cancer by interfering with specific molecules that are involved in the growth, progression, and spread of cancer.
Immunotherapy is a form of treatment that relies on the body’s immune system to fight cancer. The body’s immune system is already able to fight off bacterial and viral infections. Immunotherapy makes the immune system work against the cancer, said Dr Tan Wu Meng, consultant and medical oncologist.
“It is also about removing the camouflage some cancer cells use to hide from the immune system,” he added.
Another advantage is how it can keep on working, even after treatment stops. “Once you wake up the immune system, in some cases, you are able to keep fighting.”
He described advances in immunotherapy as “a scientific revolution happening in front of our very eyes.”
Dr Lim Hong Liang, senior consultant (medical oncology), described how immunotherapy and targeted treatments are being used for lung cancer patients.
Targeted therapy for lung cancer first became available in 2003 with an agent called Iressa. While it was initially a blunt instrument, oncologists have over time been able to use targeted treatments with greater efficiency. In the case of immunotherapy, approval was given this year for the first immunotherapy treatment for lung cancer.
With breast cancer, targeted therapy is relatively well developed, said Dr Khoo Kei Siong, Deputy Medical Director of PCC. Targeted agents exist for cancer subtypes such as ER positive and HER2-positive cancers. Immunotherapy is still new for breast cancer but has shown promise in triple-negative disease, an aggressive form of breast cancer. Dr Khoo was cautiously optimistic about its potential.
In the treatment of blood cancers, these two therapies have also made an impact. Dr Lim ZiYi, senior consultant (haematology), described how targeted therapy, specifically a tyrosine kinase inhibitor known as Gleevec, has been used to successfully treat patients with chronic myeloid leukaemia, almost doubling five-year survival rates.
Two immunotherapy agents have also been shown to be successful in attacking Hodgkins lymphoma.
During the question and answer session, many people asked about treatment for loved ones or for themselves. However, there were other questions, such as whether cancer could be cured and whether cancer cells could be starved by not consuming sugar.
On whether cancer could be cured, Dr Ang said a cure was difficult to define. “In breast cancer, recurrence may still occur after being free of cancer for 10 years whereas with lung and colon cancers, very few recurrences occur after five years.” He added: “The only time you can say you are cured is when you die, and your cancer never comes back.”
On the issue of sugar, he emphasised that everyone needs sugar to live. “If you don’t have sugar, you will go into a coma. You can’t starve cancer cells. If you want to starve the cancer, you must die first,” he stressed.
Targeted therapies and immunotherapy offer more options for cancer patients and Dr Tan recommended that people become more informed about them.
“I encourage you to have that conversation with your doctor to explore how you can live better and live longer,” he said.
By Jimmy Yap
Tags: cancer diet & nutrition, cancer relapse, immunotherapy, kidney (renal) cancer, new ways to treat cancer, seminar & workshop, targeted therapy