In a recent interview, Amy Pfeifer, PharmD, BCPS, CSP, of AllianceRx Walgreens Pharmacy, discussed the important role that pharmacists can play in the treatment of patients with prostate cancer
Pfeifer:One of the most recent advances in treatment is the use of PARP inhibitors for men with metastatic castrate resistant prostate cancer. PARP stands for poly adenosine diphosphate ribose polymerase. These inhibitors were the first class of targeted treatments approved for this type of prostate cancer. Targeted treatments act on proteins that are involved in the growth, development, and spread of cancer. PARP inhibitors were originally approved for use in ovarian and breast cancer and are taken by mouth.
There are currently 4 PARP inhibitors approved on the market, 2 of which can be used in prostate cancer. At the end of March this year, we saw our most recent approval in the prostate cancer space with the approval of another targeted treatment known as radioligand therapy. With this type of treatment, radiation can be delivered directly to cancer cells, thereby eliminating damage to healthy cells. It's given intravenously every 6 weeks for 6 doses, and like the PARP inhibitors it is used to treat the most advanced form of prostate cancer. It's so important to have these new treatment options, as advanced cancer is the most difficult type to treat. Both of these new treatment options have improved survival and quality of life in men with metastatic castrate resistant prostate cancer.
Specific to PARP inhibitors, they can cause a number of gastrointestinal side effects, such as nausea, vomiting, diarrhea, loss of appetite, and constipation. Additionally, they can cause skin rashes and fatigue. Specialty pharmacists are in a prime position to inquire whether patients are experiencing the side effects and assess the severity. Based on what the patient reports, pharmacists can offer lifestyle modifications to help them deal with the side effects and reach out to the prescriber if necessary. Based on the severity, the prescriber might want to hold the medication until the side effect resolves or decrease the dose of the medication. Temporarily holding and decreasing doses are important strategies that allow the patient to continue on the treatment, which might have a benefit for them. Additionally, PARP inhibitors can cause low red blood cell and platelet counts. So, it's recommended that patients have these monitored at least monthly. Pharmacists can remind patients about the need for this testing and just encourage them to keep all their lab and provider appointments.
Some important considerations are the patient's life expectancy, their family genetics, and the risk group, which is how severe the cancer is. Before deciding on a treatment plan, the doctor first needs to know whether the cancer has spread or if it's contained within the prostate. So, it could spread either to nearby organs or more distant sites such as the bones or lymph nodes. If it is still within the prostate or has spread to nearby organs, surgery, radiation or radiation with hormone therapy is often used. But if it has spread to those more distant sites, typically treatment begins with medications. Additionally, there are personal considerations for the patient. So just depending on the risks and benefits of each of the treatments and what they might prefer.
For prostate cancer, early detection can occur by measuring prostate specific antigen levels or PSA levels in the blood. A digital rectal exam may also be used. Unfortunately, neither one of these tests is 100% accurate and can lead to a false positive, which is thinking there's cancer when there's not, or false negatives. Both of these situations can either lead to unnecessary additional testing or a delay in treatment.
When prostate cancer is detected early, an additional issue that can come up is whether to treat the cancer. So, with most cancers, we think about early detection and treatment having the most benefits Prostate cancer is a little bit different in that it can grow slowly in some men—so slowly that it never would cause them any negative effects and it wouldn't lead to their death. So, finding prostate cancer early in these men can actually lead to what they call overtreatment, which means you're now treating a patient for a cancer that wouldn't cause them any problems. But the treatment itself can have some really serious side effects and greatly impact their quality of life.
So, based on all of this information, the American Cancer Society recommends that men make a decision about when to start screening for prostate cancer in conjunction with their doctor, depending on their age and any risk factors. So, I would say the most important thing is that men starting at age 40 go have their annual checkup and talk to their provider about when they should start testing. The nice thing about a PSA screening is that it is a blood test. So, if the time is now that they need to be screened, they can often do it that same day, either in the office or a lab nearby.
One of the main goals of our interactions with patients is to increase adherence. As I mentioned earlier, managing side effects is one of the main ways that we can help prevent the early discontinuation of a treatment that might have a positive outcome for the patient. So, with that, first of all, we will educate patients on the administration, storage, potential side effects, and expected benefits of their therapy. Here at AllianceRx Walgreens Pharmacy, we call to check in with patients every couple of weeks at the beginning of their therapy, and one of the first things that we're doing is confirming that they actually started their treatment, or you know, has there been any hesitation in taking that first dose, we know that they received the medication. So, when we call the patient if they haven't started yet, we can talk about any concerns that they might be having and work to get them on their treatment plan as prescribed. If they have started taking it, we then can talk about any side effects they're experiencing or adherence barriers that they're facing.
I think it's important to ask patients about specific side effects for their medication. So again, we could catch those reactions early and manage them through lifestyle modifications, dose adjustments, or supportive care medications that will help keep them on their treatment. Additionally, we can connect patients with other services they might need, such as financial aid programs or patient support groups. We do see ourselves as part of the patient's care team and want to do whatever we can to help that specific patient meet their treatment.