Prevalence of multimorbidity in men of African descent with and without prostate cancer in Soweto, South Africa
Authors: Mapanga Witness , Norris Shane A. , Craig Ashleigh , Pumpalova Yoanna , Ayeni Oluwatosin A. , Chen Wenlong Carl , Jacobson Judith S. , Neugut Alfred I. , Muchengeti Mazvita , Pentz Audrey , Doherty Sean , Minkowitz Shauli , Haffejee Mohammed , Rebbeck Tim , Joffe Maureen 
Published: October 2022

Objective
With increases in chronic disease, men with prostate cancer are likely to have at least one other chronic health condition. The burden and complexity of each additional chronic disease may complicate prostate cancer treatment and reduce survival. In this paper, we describe the frequency of multimorbid chronic diseases, HIV and depression among men in Soweto, South Africa (SA) with and without prostate cancer and determine whether the presence of multimorbid diseases is associated with metastatic and high-risk, non-metastatic prostate cancer.

Methods
A population-based case-control study on prostate cancer was conducted among black men in Soweto. All participants completed a baseline survey on sociodemographics, lifestyle, and comorbid medical conditions. All participants completed a depression screening survey and HIV testing at enrolment. Blood pressure measurements and blood testing for fasting glucose, total cholesterol, and high-density lipoprotein were performed on a subset of randomly selected cases and controls. For men with prostate cancer, clinical T staging was assessed with the digital rectal examination, the diagnosis was confirmed with a biopsy and PSA levels were assessed at presentation. The metastatic staging was assessed by bone scans, and this was confirmed with PSMA PET scans, CT scans and X-rays, standard for our resource-constrained setting. Normal PSA scores were used as an inclusion criterion for controls.

Results
Of the 2136 men (1095 with prostate cancer and 1041 controls) included in the analysis, 43.0% reported at least one chronic metabolic disease; 24.1% reported two metabolic diseases; 5.3% reported three metabolic diseases; and 0.3% reported four metabolic diseases. Men with prostate cancer were more likely to report a multimorbid chronic metabolic disease compared to controls (p<0.001) and more likely to test positive for HIV (p = 0.05). The majority of men (66.2%) reported at least one metabolic disease, tested negative for HIV and had a negative depression screen. The clinical characteristics of men with prostate cancer, were as follows: 396 (36.2%) had a Gleason score of 8 and above; 552 (51.3%) had a PSA score of >20ng/ml; 233 (21.7%) had confirmed metastatic prostate cancer at diagnosis. Older age was associated with metastatic prostate cancer (OR = 1.043 95% CI:1.02–1.07) and NCCN defined high-risk non-metastatic prostate cancer (OR = 1.03 95% CI:1.01–1.05), whilst being hypertensive was protective (OR = 0.63 95% CI:0.47–0.84 and OR = 0.55 95% CI:0.37–0.83) respectively for metastatic and high-risk, non-metastatic prostate cancer.

Conclusion
The high prevalence of multimorbid metabolic diseases and HIV among men with prostate cancer represents a public health concern in South Africa. There is a need to effectively address multiple chronic diseases among men with prostate cancer by incorporating coordinated care models.