How did you come to practice radiation oncology and, ultimately, proton therapy?
Good question. In medical school, what really drew me to radiation oncology is that it’s a unique branch of medicine. Cancer itself is very diverse and intricate and requires you to understand every organ system in the body. The technology and equipment are just incredibly innovative, with lots of physics and math, which is pretty unique to medicine. Plus, unlike some disciplines you really get to see the patient a lot. So the job is never boring because every patient is unique, and you really get to build these individual relationships because of how often we see our patients.
And then protons take it to the next level. There’s this incredible precision, a unique and most technologically advanced process of delivering and distributing the radiation compared to conventional linear accelerators.
What landed you at the New York Proton Center?
Coincidentally, NYPC opened the year I was applying for a position. So I was at the ASTRO convention, where typically only about five percent of people who interview actually end up getting a job. But the stars aligned. I met with Dr. Simone, who liked what I had to say and brought me aboard.
Let’s talk about prostate cancer. Who is most at risk and are there genetic or lifestyle factors men should be aware of?
I would say that every male is basically at risk for prostate cancer, every single one.
Overall, though, age is definitely the biggest factor. About 1 in 8 men will be diagnosed with prostate cancer in their lifetime, and over half of those cases are in men over 65 years old.
The problem is that because prostate cancer is so common in general, it’s hard to find particular risk factors—since a lot of people can have it without those risk factors.
As for genetic risk, there are two BRCA genes, BRCA1 and BRCA2. While both are common breast cancer risks for women, the BRCA2 gene can also predispose men to prostate cancer.
Beyond that, investigators have assessed a correlation with prostate cancer and lifestyle, and there’s probably something there. But we don’t really have hard evidence. Obesity can lead to inflammation in the body and, therefore, malignancies in general, and there has been a link between colorectal/endometrial cancer and obesity. But there’s no definitive link to prostate cancer.
Given that high degree of risk, when and how often do you recommend screening?
Again, every single male is at risk. I think the most important thing is to raise awareness of that risk.
Guidelines of the National Comprehensive Cancer Network recommend that anyone over 45 get a PSA and digital rectal exam—though it’s 40 if you’re African-American, have a germline mutation such as BRCA, or a suspicious family history of prostate cancer.
But really, any male over 40 can and should request a PSA from their primary care provider.
Let’s talk about why proton therapy is so effective. Is it just the lack of side effects, or is it actually better at eradicating the tumor?
Overall, protons “pack a stronger punch” by creating more complicated DNA damage. The idea is that you could kill more cancer cells and ultimately might have a higher cure rate.
As to side effects, the big advantage is how the protons are delivered. Instead of building up radiation from multiple different angles and then having it dissipate beyond the target, you generally just need two angles—from the left and the right hip. You can deliver a curative ultra-high dose directly to the prostate without an exit dose hitting other body parts like the bladder, rectum or bowel as much as you would with conventional radiation. This should theoretically lead to less long-term side effects such as erectile and bladder dysfunction, and rectal bleeding.
Proton therapy has the potential to reduce the risk of secondary cancers around the treatment site compared to conventional radiation, given the lower total radiation dose to the body. Additionally, if prostate cancer were to come back after being irradiated, protons can re-irradiate the cancer very effectively and offer a new chance of cure, again because the amount of total radiation to the surrounding healthy tissues is reduced compared to conventional radiation.
Is there any evidence to show that proton therapy reduces side effects?
There is really good data with over 1,400 patients treated at the University of Florida that showed patients who had proton therapy reported having fewer side effects, particularly gastrointestinal ones like rectal urgency and frequent bowel movements. We are still collecting more prospective and randomized data to produce more evidence.
Does that mean you always recommend proton therapy for prostate cancer?
Well first off, I think it’s important to point out that many prostate cancer patients just hear about a particular treatment option—usually surgery. But they need to know that many radiation treatments can achieve similar tumor control with few side effects. Radiation options include IMRT, brachytherapy, SBRT/CyberKnife—and of course proton therapy. So they need to explore and understand their options, and ultimately choose the therapy that they feel most comfortable with.
Sometimes surgery is preferred over radiation, like when the patient presents with obstructive uropathy. In other words, parts of the prostate gland are enlarged and obstruct the urinary pathway, and this obstruction will not improve with radiation and thus needs to be surgically removed. That said, there’s no situation in prostate cancer I can think of where protons could or should not be utilized relative to the other radiation modalities. Given the dosimetric advantage (less total dose to healthy tissues), it makes sense to go with protons if opting for radiation.
Watch Dr. Shaakir Hasan present at the ZERO Prostate Cancer Summit 2022
Dr. Shaakir Hasan is a radiation oncologist at the New York Proton Center specializing in proton therapy for genitourinary and prostate cancers, lymphoma, and pediatric malignancies. He is the author of more than 70 peer-reviewed publications and has presented at many international conferences.