Immunotherapy offers a new strategy in the treatment of cervical cancer, a preventable cancer.
Decades ago, the treatment for advanced cervical cancer (where abnormal cells in the cervix grow uncontrollably) was radiation. Then came clinical trials that showed that adding low-dose chemotherapy during radiation therapy (chemoradiation) improved survival outcomes. It became the gold standard worldwide for treating this cancer.
Fast forward to the present, and researchers are now developing the next paradigm for cervical cancer treatment – incorporating immunotherapy. The immune system recognises the human papillomavirus (HPV), which causes cervical cancer, as foreign to us, said Dr John Chia Whay Kuang, Visiting Consultant,
Department of Medical Oncology,
National Cancer Centre Singapore (NCCS).
“Preliminary data from
earlier clinical trials indicate that cervical cancer responds to immunotherapy which blocks the cancer.
“Efforts are now underway to incorporate immunotherapy earlier in the treatment of cervical cancer. It’s a nasty disease. Half the patients at stage 3B relapse and succumb to their cancer. Doctors really need to do more to bring the field forward and improve the cure rate,” said Dr Chia.
The worldwide trial
A worldwide clinical drug trial is now being done to explore the use of a compound, Z-100, in combination with standard chemoradiation therapy for six weeks on stage 3B cervical cancer patients. The Phase 3 trial involves about 500 patients, 20 of whom are from three centres in Singapore, including NCCS.
“Results from an earlier Z-100 study in Japan, of patients with stage 3B locally advanced cervical cancer, were encouraging. The current study is to validate the earlier results,” said Dr Chia, who is a lead investigator in the Singapore trial.
He said Z-100 helps the immune system recognise and kill cancers. It also helps the body “remember” the cancer, so that if it encounters it again, it will kill it more efficiently. This immunological “memory” is similar to what the immune system naturally activates against viral infections such as measles. The memory is lifelong, but cancer can subvert the immune system.
Incorporating immunotherapy into standard radiation therapy appears to be highly synergistic, and may overcome many barriers the cancer has against the immune system. “Developing immunological memory is associated with much better survival because if there are tiny cancer ‘seeds’ elsewhere in the body, outside the field of radiotherapy, the immune system will destroy them. We anticipate that this will translate into improved cure rates.”