There’s a lot of chatter these days about PARP inhibitors and cancer treatment. And there’s more talk about whether these cancer drugs can be combined with radiation to treat prostate cancer.
So, let’s start with some of the basics about PARP inhibitors, then dig into whether they can be combined with radiation for prostate cancer.
What is a PARP Inhibitor?
PARP stands for poly ADP ribose polymerase, according to Cancer Research UK. It’s a type of protein found in our cells that helps repair damaged cells.
When it comes to cancer, PARP inhibitors stop the PARP from repairing cancer cells. Then the cancer cells die.
Right now, PARP inhibitors are used to treat breast, ovarian, fallopian tube, peritoneal and prostate cancers. And there are trials to see if they can be used in other cancers including lung, pancreatic, head and neck, cervical, kidney cancers as well as glioblastomas, a type of brain cancer.
PARP Inhibitors for Prostate Cancer
When it comes to prostate cancer, PARP inhibitors can improve survival for prostate cancer patients when the cancer is not responding to treatment with hormone therapy — often called castration-resistant prostate cancer (CRPC).
They can also be used for patients who have certain genetic changes, according to WebMD. These types of genetic changes are found in 25% of late-stage CRPC patients.
The most common genetic mutations are BRCA1 and BRAC2. These changes make it harder for cells to fix their damaged DNA. And while the BRAC mutations increase the risk of prostate cancer and are also the reason the cancer spreads faster, the mutations also increase the PARP inhibitors’ effectiveness against prostate cancer.
PARP Inhibitors Combined with Radiation for Prostate Cancer
According to an article in the Frontiers of Pharmacology found in the National Library of Medicine, there are studies that suggest that PARP inhibitors combined with radiation can “enhance the sensitivity of cancer cells to radiation, intensify DNA damage, and trigger cell death. Combining radiotherapy with PARP inhibitors in clinical trials has enhanced the response rate and progression-free survival of diverse cancer patients.”
However, the combination of PARP inhibitors and radiation for cancer is in its infancy.
While the data is encouraging, much more research is needed to see if the two therapies should be combined and if it increases long-term survival.
As we wait for answers, we know there is hope.
In the meantime, radiation for prostate cancer remains a gold standard of treatment. And radiation using CyberKnife is among the most advanced and successful treatments.
CyberKnife for Prostate Cancer
CyberKnife uses image-guided robotic technology to deliver targeted radiation called stereotactic body radiation therapy (SBRT) directly to the cancer or tumor without harming healthy tissue, for example.
“CyberKnife is the most sophisticated and refined way to treat most tumors,” says Dr. Mark Pomper, board-certified radiation oncologist and medical director of CyberKnife Center of Miami, South Florida’s state-of-the art, free standing radiation treatment center on CyberKnife Miami’s YouTube Channel.
CyberKnife Treatment for Prostate Cancer in South Florida
CyberKnife alone can treat prostate cancer, especially if it’s low grade and localized to the prostate. For early prostate cancers, the success rate with CyberKnife is 98%, and CyberKnife treatment has lower risks of long-term side effects including incontinence or erectile disfunction when compared to traditional radiation and surgical options.
CyberKnife can also be used in combination with other treatments if necessary, during early stages or as the disease progresses. And it can be an option for CRPC.
According to one case study from November of 2020, a 69-year-old man with urethral metastasis of CRPC (hormone-resistant prostate cancer that spread to the urethra) had CyberKnife treatment with no adverse effects.
“There has been no recurrence for 50 months. To the best of our knowledge, there is no other case of urethral metastasis of the CRPC successfully controlled with CyberKnife radiosurgery in the literature.” according to the abstract.
The CyberKnife Advantage
CyberKnife has some distinct advantages over other forms of radiation for prostate cancer, including CRPC. It can destroy prostate tumors while leaving the surrounding healthy tissue alone.
Here are some benefits of CyberKnife:
Fewer treatments
CyberKnife requires five treatments, compared to 30–40 treatments for traditional radiation.
Faster recovery
Patients can usually resume normal activities almost immediately after treatment.
Less side effects
CyberKnife can minimize the risk of side effects by delivering radiation with sub-millimeter accuracy.
Preserves healthy tissue
CyberKnife can precisely target the prostate while minimizing radiation to healthy tissue.
Maintains sexual function
A clinical study found that the majority of patients treated with CyberKnife maintained sexual function.
Here’s how CyberKnife works:
- Implant markers
Before treatment, a urologist implants four tiny gold markers into the prostate to track the prostate movement. - Create a treatment plan
A team of physicians uses MRIs, CT scans, and 3D technology to create a treatment plan. - Deliver radiation
The CyberKnife’s robotic arm delivers radiation in a series of fractions, with each fraction lasting about 30 minutes. The system automatically tracks and adjusts the radiation beam in real time to account for prostate movement. Some possible side effects of CyberKnife include
- Constipation
- Hemorrhoids
- Bleeding from the rectum or urinal tract
- Difficulty urinating
- Frequent and urgent urination
- Blood in the stool
At the CyberKnife Center of Miami, we have successfully treated hundreds of prostate cancer patients from across the country and right here in South Florida with excellent results.
It’s noninvasive.
CyberKnife’s treatments can be done in five therapy sessions over 10 days instead of 42 over three months with other types of radiation treatments.
CyberKnife can be a radiation treatment option even for patients who have had radiation in the past or in the event of a recurrence.
If you would like to find out more about CyberKnife, call the prostate cancer treatment experts at 305-279-2900 or go to our prostate cancer website now.