CALLING OFF CANCER
INTRODUCTION-
A new drug which unleashes the body's immune system promises the cure for rectal cancer sans surgery or chemotherapy. The first instance where 100% cure in treated patients with any cancer, with complete disappearance of the cancerous tumours, is because of dostarlimab. There is a change of strategy from attacking the cancer cells directly with drugs or radiation to helping the body battle and beat cancer with its own troops.
Dostarlimab-
- Dostarlimab belongs to a group of monoclonal antibodies called "checkpoint inhibitors."
- They are synthetic antibodies which block the proteins that cancer cells produce to prevent the body's immune system from attacking them.
- It is a game of blocking the blocker, the native immune system which has recognized the cancer threat is not impeded in launching its attack on the malignant cells.
- This form of immunotherapy does not attack the cancer cells directly but unshackles the body's defenders.
Explanation-
- Among the key components of the human immune system are T-cells, containing checkpoint proteins on their surface.
- Some of the T-cells switch on the immune response to fight infections and cancers, while others switch off the immune response when it threatens to become hyperactive and damage the body's tissues.
- While the body tries to maintain a fine balance between these switches, cancer cells may attempt to subvert the process by blocking the action of proteins that regulate the immune system's response to a recognized danger.
- Checkpoint inhibitors are named according to the type of protein they block- CTLA-4 inhibitors, PD-1 inhibitors and PD-L1 inhibitors.
- Dostarlimab is an inhibitor of the Programmed Cell Death Protein(PD-1)
- Other checkpoint inhibitors have been used for treating patients with melanoma, Hodgkin lymphoma and non-small cell lung cancer.
Pros-
- This theory is a marvel. This may unleash the immune system to operate the way it was intended to work.
- Within days or weeks, the body's own defences could destroy a tumour that toxic chemotherapy couldn't kill over months or years.
- The locks would be taken off the T-cell guns, the canons unshackled, and cancer's magic trick is exposed.
- Phase 2 clinical trial, involved patients who have rectal cancer, and dostarlimab therapy was proposed as an early-stage intervention.
- Long-term duration of protection from recurrence is not known yet and the trial is continuing.
Cons-
- Small numbers can be misleading while estimating statistical significance. Small numbers in a non-random, purposive sample follow a poison distribution.
- A small formula, 3/n ( n is the sample size) provides an upper estimate of negative outcomes that can possibly occur even where zero failures were observed.
- The zero failure rate reported in the dostarlimab study is statistically compatible with a possible 16.6% rate of treatment failure, because of the small sample size of 18.
- A larger study would help to shrink the estimate of possible failure.
Conclusion-
If the dostarlimab continues to demonstrate a high level of success in providing a complete cure for rectal cancer.
source-https://indianexpress.com
