Modelling survival and factors associated with HIV-infected and -uninfected patients of prostate cancer at the University Teaching Hospital, Lusaka, Zambia

Abstract

: Incidence and mortality rates as a result of prostate cancer (PCa) remain high in the world, especially among the population of people living with human immunodeficiency virus (HIV), with high mortality mainly in Africa. Therefore, this study determined the survival rates among HIV-positive compared to HIV-negative PCa patients and factors associated with mortality. This was a retrospective cohort study of PCa patients at Cancer Disease Hospital in Lusaka, Zambia, for the observational period of 5 years. Patients were followed up using mobile phone calls to understand the time contributed from time at diagnosis to death. Patients who were lost to follow-up were censored at the date of last follow-up at the hospital. A total of 662 cases were evaluated. The total person time at risk was 7,548 months. After 5-year follow-up, there were 290 (43.8%) deaths, suggesting crude mortality rate of 430 per 10,000 persons per year. The overall median survival time was 16 months. In an adjusted model, the following variables had a statistically significant effect on the hazard of death: 1-year increase in age, increased the hazard of death by about 3%, AHR: 1.03 (95% CI: 1.02, 1.05, p = 0.001); HIV-positive patients had reduced hazard of death by about 41%, AHR: 0.59 (95% CI: 0.44, 0.79, p = 0.001); Gleason score (GS) less than or equal to 8, the patients with GS greater than 8 had increased hazard of death by about 43%, AHR: 1.43 (95% CI: 1.27, 1.59, p = 0.001); those on hormonal therapy had reduced hazard of death by about 28% AHR: 0.72 (95% CI: 0.54, 0.94, p = 0.018) and those presented with tumour stages I and II had reduced hazard of death by about 82%, AHR: 0.18 (95% CI: 0.04, 0.78), p = 0.021). Survival from death following whether a patient was HIV-positive or not was more in the HIV-positive compared to HIV-negative and this could be due to high GS in the HIV-negatives compared to HIV-positives and late-stage diagnosis of the disease at the hospital especially among the HIV-negative patients as evidenced by the increased hazard of death compared to HIV-positives. Therefore, medical check-up such as screening for PCa which leads to early diagnosis of the cancer must be encouraged in men.

Keywords:

• Cancer Disease Hospital
• human immunodeficiency virus
• mortality
• prostate cancer
• Zambia

Acknowledgments

We acknowledge Cancer Disease Hospital in Zambia for enabling us to get data by reaching out to the patients or family members of the cancer patient during the follow-up.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

The data for this article supporting the findings will be made available once requested by the reviewer for supporting the conclusions.

Author contributions

KM: conceptualization. SC, MM, KM and VM: data curation. KM, VM and PK: investigation and methodology. KM and PM: formal analysis. KM: writing—original draft: KM, VM and PK writing—review and editing. All authors read and approved the final manuscript and contributed to the development of research.

Ethics statement

University of Zambia Biomedical Research Ethics Committee (UNZABREC) which is one of the ethical committee in Zambia gave the approval of this research with reference number 447-2019 before the study was undertaken.

Additional information

Funding

No funding was received.

Notes on contributors

Kelvin Mwangilwa

Kelvin Mwangilwa is a Medical Statistician.

Moses Mwale

Moses Mwale is a Data spacialist.

Susan Citonje

Suzan Chitengi is Medical Doctor and spacialist in Oncology.

Michael Vinikool

Micheal Vinikoor is a Medical Doctor/Research and Professor in Public health.

Patrick Musonda

Patrick Musonda is a Professor in Medical Statistics.