Julie Eggert, RN, PhD, GNP-C, AOCN, and Lori Williams, PhD, RN, AOCN, OCN, presented a session at the 2012 ONS Annual Congress titled "PARP Is a Perp: Biology of Cancer Update."
In this session, you'll learn about the action of new therapies based on the PARP enzyme in relation to cancer biology. Identify your role in patient education and symptom management during PARP inhibitor therapy.
PARP is an acronym for poly (ADP-ribose) polymerase. PARP is a protein that has several roles in cellular processes, mostly in DNA repair and apoptosis. Normal cells may utilize PARP to help repair themselves, but here's the clincher: cancer cells may also use PARP to repair DNA damage. This, in turn, will allow the cancer cells to multiply, therefore contributing to tumor growth.
So, why all the hype regarding PARP these days? Well, the answer is PARP inhibitors. A PARP inhibitor is a drug that blocks PARP proteins from repairing damaged cancer cells; they have the potential to impair tumor growth without damaging normal cells. PARP inhibitors may be used to prevent repair in cancer cells damaged by chemotherapy and radiation. PARP inhibitors have demonstrated significant anti-tumor effects in several types of cancer:
- BRCA 1 & BRCA2 inherited tumors
- BrCa1 phenotypic basal-like breast cancers
- Sporadic BrCa1 tumors
- Uterine cancer
- Ovarian cancer
- Prostate cancer
- Colorectal cancer
- Squamous cell lung cancer
- Metastatic Melanoma
PARP inhibitors have gained quite a bit of attention for their use in women who are BRCA1 and BRCA2 carriers or have triple negative breast tumors. People who have BRCA1 and BRCA 2 genetic mutations are at very high risk for developing breast cancer. Normal BRCA genes can suppress tumor formation, but mutated BRCA genes are defenseless against cancer cells.
Here is a list of the PARP inhibitors discussed at the ONS session:
It is important to note that PARP inhibitors are still investigational, and patients may participate in a clinical trial if eligibility requirements are met.
Even though the PARP inhibitors are not considered chemotherapy per se, they still could have potential side effects. There is currently no treatment regimen for symptoms related to PARP inhibitors, so general symptom management would apply.
Although these particular drugs are still in the clinical trial phases, the oncology nurse should be aware of the most current information surrounding PARP inhibitors as it pertains to:
- Clinical trials
- Patient education
- Nursing research
We need to keep a close eye on the future of these PARP inhibitors; these drugs may help to increase the effectiveness of chemotherapy without serious side effects.
You can review the bibliography and the slide deck here.
Are any of you currently treating patients on a clinical trial with a PARP inhibitor?