Immunotherapy is an emerging treatment for cancer which targets malignant cells without harming the healthy ones

Not many who are diagnosed with late stage cancer gather enough courage to go in for a high- risk surgery.

Four years ago 43 year old Aruna Tyagi underwent one of the most complex surgeries for cancer, Whipple operation, after being diagnosed with the rarest form of pancreatic cancer. And this was just the beginning of her trials and tribulations.

About a year after the tumour was removed, Tyagis cancer recurred. She went under the knife for the second time and was also given a few cycles of chemotherapy and radiation.

But nothing worked to halt the spreading cancer. It was at that point that she decided to take a chance on a new treatment, dendritic therapy. “ Aruna wasnt responding well to the chemo and radiation, so we decided to put her on dendritic therapy which, to our surprise, slowed the spread of cancer after a few cycles,” says Dr Sameer Kaul, senior consultant, surgical oncology, Indraprastha Apollo Hospital. Tyagi has been on this treatment for three years now and has been living an active and healthy life for this period. “ I felt a difference in my health after 3rd or 4th cycle of dendritic therapy. Three years of therapy has given me a new life,” she says.

Immunotherapy based on the dendritic cell therapy is a new modality of cancer treatment which plays a role in the repair, stimulation or enhancement of the immune system. “ Dendritic cell therapy is emerging as a very useful form of treatment for cancer patients. And, I have recommended this to my patients on a few occasions,” says Dr Purvish Parikh, former chief of medical oncology at Tata Memorial Hospital, Mumbai.

Getting the immune system to attack cancer has fascinated scientists for decades, because it promises to have fewer side effects than chemotherapy. While conventional treatment for cancer works by killing malignant cells in the body, immunotherapy makes the body capable enough of fighting its own battle and targets only cancerous cells. Boosting the immune system can help people fight cancer, but this boost needs to be large enough to overcome the already reigning cancer cells.

Though immunotherapy has a fairly small role in treatment currently, oncologists believe this is the future weapon to deal with cancer. “ We are beginning to understand immunotherapy or targeted therapy. Its too early to say much about it,” says Dr Rangaraju Ranga Rao, chairman, medical oncology at Artemis Health Institute, Gurgaon.

The bodys immune system can be stimulated in several ways. One way of doing it is by immunisation of the patient i. e administering a cancer vaccine.

This way the patient's own immune system is trained to recognise tumour cells as targets to be destroyed. And, the recent development to add credibility to the treatment is US FDA's approval to the cancer vaccine, a drug that trains the bodys own immune system to fight the disease. T HE DRUG, Provenge, developed by the Dendreon Corporation is approved to treat advanced prostate cancer. The second way to strengthen the immune system is through the administration of therapeutic antibodies as drugs, in which case the patient's immune system is employed to destroy tumour cells by the therapeutic antibodies. One such method is dendritic cell therapy.

Dendritic cells are immune cells that form part of our immune systems. Dendritic therapy involves the extraction of white blood cells from the patients blood and exposure of these to cancerous cells taken from the tumour. This exposure transforms white blood cells into better cancer- fighting cells which are then infused back into patients blood. The therapy is administered for the treatment of solid tumours only. “ Since blood cells are used, those with blood cancer cant be treated with this,” says Dr Samuel J K Abraham of Nichi- In Centre for Regenerative Medicine ( NCRM), Chennai.

While chemotherapy and radiation are already being used to kill rogue cells and do succeed to some extent, these treatments have plenty of side effects. This is the reason why oncologists are recommending immunotherapeutic treatment to cancer patients. “ Unlike conventional cancer treatments, immunotherapy has no side effects and chances of relapse are less since the body throws out the cancer rather than suppressing it like medicines,” says Dr Abraham. A STUDY done by NCRM showed that immunotherapy improved the impact of conventional treatment “ Though its better to give this therapy along with conventional treatment to increase chances of recovery, it can be given solo for cases in advanced stages where surgery or medicines are not working. There is an increase in survival rate for these patients,” says Dr Abraham.

Dr Rao also believes a combination of therapies could be the best way to deal with cancer.

“ Immunotherapy has shown encouraging results in advanced cancer patients who were given this therapy in combination with the conventional treatment. We too would soon begin trials on locally advanced mouth cancer patients,” says Dr Rao.

Critics of dendritic therapy, however, feel that the benefits of the therapy dont outweigh the exorbitant cost. According to Dr Shyam Aggarwal, head of oncology, Sir Ganga Ram Hospital, though dendritic therapy has shown some good results in colon, kidney and skin cancer, it is still at an experimental stage.

“ The therapy doesnt seem any worth it so we arent prescribing it to our patients,” says Dr Aggarwal.

However, with the approval of the first therapeutic cancer vaccine many doctors feel confident prescribing this therapy to their patients. “ Most of the cancers work in similar fashion so the approval of the drug for prostate cancer is in a way a step forward,” says Dr Rajeev Sood, oncologist, Rajiv Gandhi Cancer Hospital.