Ovarian cancer treatment is complex and often comes with a host of side effects. One of the newer treatments on the block, PARP inhibitors, show promise in the fight against ovarian cancer, particularly among women who carry a BRCA genetic mutation, though recently shown to provide some benefit to almost all women.
The American Society of Clinical Oncology (ASCO) guidelines recommend PARP inhibitors be offered to women, with or without genetic mutations, who are newly diagnosed with stage III or IV ovarian cancer and have improved with chemotherapy.
Read MoreCommon Side Effects of PARP Inhibitors
Whether or not you’ll experience significant side effects from PARP inhibitors depends on a number of factors, including which PARP inhibitor you’re taking, what dose you’re ingesting, and whether you’re using it alone or in combination with other therapies. Still, the side effects of most PARP inhibitor protocols can overlap across each of the three FDA-approved PARP inhibitors and include:- Nausea
- Vomiting
- Stomach upset
- Fatigue
These side effects can be intolerable for some patients, but in almost every case, doctors can offer options to alleviate or even eliminate them. Plus, when it comes to gastrointestinal upset, doctors have multiple tools at their disposal. Common anti-nausea medications include:
Most of these anti-nausea medications last for more than eight hours. So if you have a single day dosing with a PARP inhibitor, taking anti-nausea medication the evening before treatment can help reduce or even eliminate nausea.
Since PARP inhibitors disrupt how cells repair damaged DNA, killing off tumor cells and healthy cells simultaneously, the bone marrow and blood cells may take a hit. As a result, a subset of patients encounter side effects of PARP inhibitor treatment related to bone marrow suppression. Two of the most common:
- Reduced blood cells counts: Since bone marrow makes both red and white blood cells, PARP inhibitor treatment may cause a drop in these cell counts. Patients may notice fatigue, reduced immunity, and light-headedness.
- Reduced platelet counts: Platelets play a role in blood clotting, so low platelet counts can cause excessive bleeding, easy bruising, and blood in the urine or stool.
“There are also some rare, potentially life threatening side effects with PARP inhibitors that affect less than 1 to 2% of the population,” Dr. Eskander says. “One is acute myelogenous leukemia (AML) or myelodysplastic syndrome (MDS). Another is pneumonitis, or inflammation of the lung tissue.”
Treating Side Effects
No matter which PARP inhibitor protocol you’ve embarked on, doctors can modify your treatment schedule to reduce side effects. A few possibilities:
- Discontinue treatment for a brief time period
- Reduce the dose
- Transition to another PARP inhibitor to see if there’s any improvement
Dr. Amanika Kumar of The Mayo Clinic who spoke to SurvivorNet, cautioned that women still need to speak with their doctor to evaluate the benefit of taking a PARP inhibitor to extend life, because there are very real side effects due to the toxicity of the drug.
"Patients with HRD (homologous recombination deficiency) have a far better response than those without and those with BRCA mutations even more so. It is on us as clinicians to help patients understand the risks and benefits of treatment. Patients that have no mutation or HRD may choose not to go on maintenance (in fact I recommend they don't) because there is real toxicity to these meds."
According to Dr. Eskander, navigating PARP inhibitor treatment is really no different from any other form of therapy.
“It’s about education to empower our patients. It’s about communication, so that our patients feel confident in reaching out to us, and it’s about strategies to manage those side effects when patients experience them,” Dr. Eskander says.
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