A recent study found that taking antibodies before immunotherapy reduces the survival rate in cancer patients.
The scientists of Imperial College London suggest that antibiotics remove the beneficial bacteria from the gut. This results in the weakening of the immune system. As an outcome, it reduces the effect of immunotherapy in boosting the immune system to fight against cancer cells.
The study involved around 200 participants from two NHS hospitals.
Effect of antibiotics before immunotherapy
The researchers found distinct results from the study. The patients who took broad-spectrum antibiotics for common diseases survived for a median of two months after immunotherapy. On the other hand, the patients without antibiotic use survive for 26 months.
This is a significant result. The major difference in survival rate and clear evidence from CT scans proves the faster growth of tumors due to antibiotics use. This has worked like an alarm for researchers to conduct more studies so that they could guide the therapists.
Dr. David Pinato said that antibiotics noticeably remove the gut microbiota to some extent. If a person has a healthy gut microbiome, his immune system can effectively fight cancer.
An important finding of the study was that all antibiotics have the same effect on all types of cancer. For instance, in lung cancer, chest infections are very common. The patients who used antibiotic before immunotherapy had a survival rate of a median for 2 months.
In contrast, those patients who did not use any antibiotic survived for 26 months after immunotherapy.
In melanoma, the survival rate in cancer patients was 3.9 months compared with 14 months for no use of antibiotics. Similarly, in other types of tumors, the rate was 5 weeks versus 11 months.
Another important finding of the study was that some patients took antibiotics during their immunotherapy. However, in their case, the antibiotics did not cause adverse effects on their survival.
The study is published in the journal Jama Oncology.
Effectiveness of immunotherapy
Some people respond better and adapt more to immunotherapy. In almost 20% of cancer patients, cancer nearly disappears and they have high chances of complete cure. However, this does not happen to all patients.
Pinato said that some other studies have found different factors that can reduce the survival rate in cancer patients. However, this association has a solid base and we need to pay attention to it.
The use of antibiotics before immunotherapy is not the only significant factor for less survival span. However, researchers are willing to find out how much it affects survival as a factor itself.
Pinato said that these findings compel us to be more careful about prescribing antibiotics to different cancer patients. We should find out whether we need to find a threshold to prescribe any antibiotic to cancer patients or not.
The health services are already advised to give antibiotics only in need to avoid antibiotic resistance in the body. However, this finding adds more stress to the use of antibiotics more cautiously.
Moreover, we also need to find out how we can strengthen the gut microbiome in cancer patients. Also, how it can help the immune system to fight cancer.