Parkinson’s disease is linked with at least 16 types of cancer, according to the results of a new study based on East Asian populations. The majority of prior research has been conducted in Western populations.

The study authors discovered a diagnosis of Parkinson’s disease (PD) was not linked with increased risk of ovarian, thyroid, or breast cancers. PD did, however, appear associated, as measured by increased hazard ratios, with 16 other cancers.

The associated cancer include:

At least 25 epidemiological studies have been carried out in the last 50 years on the potential links between PD and cancer.

Most of the studies demonstrated that people with PD had a lower risk of cancer compared to those without PD. But most of those studies were done in Western populations. Tt has since become more evident that genetic background plays a key role in disease development.

The authors conclude that:

“Based on this nationwide study on the association between PD [Parkinson disease] and cancer risk, we conclude that PD is a risk factor for most cancer in Taiwan. In our cohort, only breast, ovarian and thyroid cancers show no association with PD. Further studies are needed to clarify whether our findings can be applied to other East Asian populations. The striking differences between our study and the previous studies in Western cohorts suggest the importance of ethnicity and environmental exposures in disease pathogenesis."

In a related commentary Mary Ganguli, MD, MPH, of Western Psychiatric Institute and Clinic, writes:

“Clearance of defective mitochondria, through a form of autophagy known as mitophagy, enables quality control of these important organelles. New rounds of mitochondrial biogenesis are promoted by clearance of ROS-generating mitochondria disabling further mutagenesis, likely important in PD and certainly in cancer. We believe that the nuclear protein high-mobility group box 1 (HMGB1) is central to the emergence of cancers in the setting of chronic stress. We also believe HMGB1 is likely important in both compartments, given its ability to promote both nuclear and mitochondrial DNA repair. It binds to α synuclein, which is implicated in PD, serving as an important intermediary between nuclear and mitochondrial functions. HMGB1 promotes autophagy; its loss or diminution may promote disordered cellular homeostasis associated with both PD and cancer."

Association Between Parkinson Disease and Risk of Cancer in Taiwan Pei-Ying Lin, MD; Shih-Ni Chang, MS; Tzu-Hung Hsiao, PhD; et al. JAMA Oncol. Published online June 18, 2015. doi:10.1001/jamaoncol.2015.1752

Parkinson Disease and Malignant Disease: Minding Cancer’s Own Business Mary Ganguli, MD, MPH; Michael T. Lotze, MD JAMA Oncol. Published online June 18, 2015. doi:10.1001/jamaoncol.2015.1810

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