The medical records of all men, whether still living or deceased, diagnosed with PCa from two private urologists’ offices were reviewed. One urologist was based in the country, in the south-western part of the island, while the other was based in Kingston but saw patients on a fortnightly basis in the south-western region of Jamaica as well. The study was approved by the Ethics committee of the University of the West Indies.
Cases were men with histologically confirmed PCa or men with overwhelming clinical, biochemical and/or radiological evidence of PCa who did not undergo biopsy but were presumed to have the disease. The latter comprised less than 1 % of cases and invariably had PSA levels > 500 ng/ml.
Information on patients’ age, address, date at presentation, initial PSA level, local tumour stage based on digital rectal examination (DRE) findings, biopsy Gleason score and initial treatment received were extracted from the patients’ files. The records spanned a 12 year period from 1999 to 2011.
Setting
Although urban is defined by the Statistical Institute of Jamaica (STATIN) as a place that “has a population of 2000 or more persons and provides a number of amenities and facilities which in Jamaica indicates modern living”, for the purpose of this study only cities and capitals of parishes were considered urban. The capital city of Jamaica, the largest urban centre, is located within the geographic boundaries governed by the municipal authority of the parishes of Kingston and St. Andrew (KSA) found in the south-eastern part of the island and has a population of 670,000 people. It has two tertiary-level care public hospitals and 12 urologists.
The designation ‘rural’ was applied to patients residing outside of named capital towns and cities in the south-western part of Jamaica which was one of the two study settings.
One urologist practices solely in the south-western region of the island, a country area comprised of 4 parishes – Westmoreland, St. Elizabeth, Manchester and Clarendon with a combined population of 738,000 people (Fig. 1). He is the only fixed practicing urologist in this region. His practice is comprised of 3 locations, Junction (St. Elizabeth), Mandeville (Manchester) and May Pen (Clarendon). Mandeville and May Pen are the capital towns for their respective parishes of Manchester and Clarendon and are considered urban centres. Junction is a small non-capital town in the parish of St. Elizabeth and is considered rural for the purpose of this study.
The south-western region of the island consists of many rural villages and extremely remote areas with very hilly terrain. The majority of patients accessing private urological care for prostate cancer from this region of the island would be seen by the fixed country urologist.
A minority of country patients may be managed by general surgeons, opt to go to a city-based urologist in Kingston or Montego Bay, or may be seen by itinerant urologists who travel from Kingston to the country on an infrequent basis.
The city-based urologist practices in Kingston and May Pen, the latter being the capital town for the parish Clarendon and therefore an urban centre, situated in the mid-southern portion of the island (Fig. 1) where he sees patients fortnightly. Patients seen by both urologists in the country offices may be from either urban or rural settings. Patients from the country seen in Kingston by the Kingston-based urologist were excluded from the analysis.
Clinical and pathologic assessments
Both urologists used the AJCC TNM staging system to assess local prostate tumour stage clinically on DRE. However, because of slight differences in the classification of the sub-categories of T2 based on the 1992 versus the 2003 TNM staging systems, only general T categories (T2, T3 and T4) and T1c were used in the analysis to minimise misclassification errors. PSA levels done in KSA were done by one of three medical laboratories while those outside of Kingston and St Andrew were done by a limited number of medical laboratories inclusive of the same three laboratories in Kingston which had branches in the country.
Most prostate biopsies done in KSA were done by a single radiologist under transrectal ultrasound guidance taking a minimum of 12 to 16 cores. Prostate biopsies outside of KSA were mostly done under transrectal ultrasound guidance but men with palpable, locally advanced tumours (T3 and T4) commonly had finger-guided biopsies, taking fewer cores in the process. Specimens from KSA were evaluated by a single pathologist in almost all cases and this was the same for outside of KSA.
Analyses
The clinico-pathologic features of men with prostate cancer from urban and rural areas were described using summary tables. As appropriate, means of the two groups were compared using the Student’s t-test, median PSAs were compared with the Wilcoxon rank-sum test. Clinical T stage was re-categorised into 2 groups organ-confined (T1 and T2) and locally-advanced (T3 and T4) disease and associations with geographic location determined using Pearson’s chi squared test. P-values of <0.05 were deemed statistically significant.
Regression analysis was also done to control for confounding and identify independent predictor variables for rural–urban status. The variables included in the regression analysis were those associated with rural/urban location in bivariate analyses. The outcome ‘rural’ and ‘urban’ was coded as one and zero respectively. Potential independent variables identified through bivariate analysis were entered in the model. For logistic regression Gleason scores were recoded as 5–6 ‘low’, 7 ‘intermediate’ and 8–10 ‘high’. DRE stage was converted to a binary variable with Stages T1c and T2 being combined as ‘organ-confined disease’ and Stages T3 and T4 being ‘locally-advanced disease’ (i.e. disease extending beyond the prostatic capsule).
The Statistical Package for the Social Sciences (SPSS) version 17 was used for the analyses.