A recent study by researchers at the National Taiwan University College of Medicine (Taipei, Taiwan) has demonstrated that Parkinson’s disease (PD) is associated with 16 types of cancer. The study was conducted to explore this association in an East Asian population as most previous data had been collected in Western populations. The article was published online in the journal JAMA Oncology.
In excess of 25 epidemiological studies have been performed over the past 50 years investigating the link between PD and cancer. Most of these studies have demonstrated that individuals suffering from PD had a decreased risk of cancer compared with those without PD. The majority of these previous studies were carried out in Western populations; however, it has become increasingly clear that genetic background has an important role in the development of PD.
The authors of the study utilized the Taiwan National Health Insurance Research Database to create a final study group of 62,023 patients newly diagnosed with PD from 2004 to 2010, and 124,046 control participants without PD.
It was discovered that PD diagnosis was not associated with an increased risk of breast, ovarian or thyroid cancers. Conversely, hazard ratio analysis demonstrated that PD appears to be associated with 16 other cancers, including malignant brain tumors, gastrointestinal tracts cancers, lung cancers, some hormone-related cancers, urinary tract cancers, lymphoma/leukemia, melanoma and other skin cancers.
However, limitations of the study are also stated by the authors. These include the possible underestimation of PD incidence, the omission of smoking status from their analysis, speculation regarding pesticide exposure and questions surrounding genetic correlations.
The authors conclude that PD is a risk factor for most cancer in Taiwan, but highlight the need for further studies to ascertain whether the findings can be applied to other East Asian populations. The authors also suggest the importance of ethnicity and environmental exposures in disease pathogenesis.