In News: In a medical trial, 12 patients in the United States were completely cured of rectal cancer without requiring any surgery or chemotherapy.
- The trial used a monoclonal antibody called dostarlimab every three weeks for six months for the treatment of a particular kind of stage two or three rectal cancer.
- The trial showed that immunotherapy alone – without any chemotherapy, radiotherapy, or surgery that have been staples of cancer treatment – could completely cure the patients with a particular kind of rectal cancer called ‘mismatch repair deficient’ cancer”.
- No cases of progression or recurrence had been reported during the follow-up
What is this deficiency, and how was it cured?
- ‘Mismatch repair deficient’ cancer is most common among colorectal, gastrointestinal, and endometrial cancers.
- Patients suffering from this condition lack the genes to correct typos in the DNA that occur naturally while cells make copies.
- The immunotherapy belongs to a category called PD1 blockades that are now recommended for the treatment of such cancers rather than chemotherapy or radiotherapy.
- PD1 is a type of protein that regulates certain functions of the immune system, including by suppressing T cell activity, and PD1 blockade therapy looks to release the T cells from this suppression.
- By giving the PD1 blockades, we release and T cells to destroy the cancerous growth
If PD1 therapy was already in use, what’s new in the trial?
- Earlier, this therapy was used post-surgery, but the study has shown that a surgery may not be required.
- Although the therapy is usually used for cancers that have metastasised (spread to locations other than where the cancer formed), it is now recommended for all mismatch repair deficient cancers as they result in quicker improvement and lesser toxicity as compared to traditional chemotherapy and radiotherapy.
- This study shows that even the surgery was not needed in these patients
Cost is a concern
- Immunotherapies are expensive and unaffordable for most people in India
- An immunotherapy treatment can cost around Rs 4 lakh per month, with patients needing the treatment for six months to a year.
Source: Indian Express