# Association of Sporadic and Genetic Parkinson’s Disease with Cancer: Insights from the PPMI Cohort

## TL;DR

This study explores the link between Parkinson’s disease and cancer using the PPMI dataset, finding varied cancer risks in PD patients and genetic subgroups.

## Contribution

The study provides insights into cancer incidence in sporadic and genetic Parkinson’s disease, highlighting gender-specific differences.

## Key findings

- Cancer often occurred before PD diagnosis in most patients.
- Skin cancer and prostate cancer were the most common cancers in PD patients.
- Female PD patients showed increased cancer risk, including higher breast cancer risk compared to controls.

## Abstract

Background/Objectives: Prior studies have reported a complex interplay between Parkinson’s disease (PD) and malignancy. Although patients with PD often present a lower general risk for several types of cancer, some forms—including melanoma—show elevated frequency. The present work aimed to evaluate the occurrence of cancers other than melanoma among individuals with sporadic and genetic PD. Methods: We examined medical histories from 1888 participants with PD and 438 healthy controls (HCs) using the Parkinson’s Progression Markers Initiative (PPMI) dataset, with a focus on neoplastic disease. In cases with positive cancer history, genetic information was additionally assessed [carriers of mutations in the most prevalent PD-related genes were evaluated]. Results: Our results demonstrate that cancer incidence was antecedent to PD diagnosis for the majority of PD patients, while the most common cancer types apart from malignant melanoma were non-melanoma skin cancer and prostate cancer. Conclusions: Regarding genetic PD patients, the most common cancer types in the LRRK2 and GBA1 groups were skin cancer and lymphoma, while PRKN/PARK2 carriers appeared with an overall increased incidence of cancer. No statistically significant results were observed comparing cancer incidence in PD patients to that in healthy control individuals. Interesting results were obtained by dividing the patients by gender, showing increased cancer risk in female PD patients and female LRRK2 carriers, along with increased breast cancer risk in female PD patients compared to healthy controls.