Impact of socioeconomic status on prostate cancer diagnosis, treatment, and prognosis

Impact of Socioeconomic Status onProstate Cancer Diagnosis, Treatment,and PrognosisElisabetta Rapiti, MD, MPH1; Gerald Fioretta, MSc1; Robin Schaffar, MSc1; Isabel Neyroud-Caspar, MD1;

Helena M. Verkooijen, MD, PhD1,2; Franz Schmidlin, MD3; Raymond Miralbell, MD4;

Roberto Zanetti, MD1,5; and Christine Bouchardy, MD, MPH1

BACKGROUND: The objective of the current study was to evaluate the impact of socioeconomic dis-

parities on prostate cancer presentation, treatment, and prognosis in Geneva, Switzerland, in which

healthcare costs, medical coverage, and life expectancy are considered to be among the highest in the

world. METHODS: This population-based study included all patients diagnosed with invasive prostate can-

cer among the resident population between 1995 and 2005. Patients were divided into 3 socioeconomic

groups according to their last known occupation. Compared were patient and tumor characteristics and

treatment patterns between socioeconomic groups. Cox multivariate regression analysis was used to

assess and explain socioeconomic inequalities in prostate cancer-specific mortality. RESULTS: Compared

with patients of high socioeconomic class, those of low socioeconomic class were more often foreigners,

were found less frequently to have screen-detected cancer, were found to have a more advanced stage of

disease at diagnosis, and less often had information regarding disease characteristics and staging. These

patients underwent prostatectomy less frequently and were more often managed with watchful waiting.

The risk of dying as a result of prostate cancer (hazards ratio [HR]) in patients of a low versus high socioe-

conomic status was increased 2-fold (95% confidence interval [95% CI], 1.5-2.6). After adjustment for

patient and tumor characteristics and treatment, the mortality risk was no longer found to be significantly

increased (HR, 1.2; 95% CI, 0.8-1.6). CONCLUSIONS: In the current study, patients of low socioeconomic

class were found to be at increased risk of dying as a result of their prostate cancer. This increased mortal-

ity is largely attributable to delayed diagnosis, poor diagnostic workup, and less invasive treatments in

these individuals. Cancer 2009;115:5556–65. VC 2009 American Cancer Society.

KEY WORDS: diagnosis, prostate cancer, socioeconomic status, survival treatment.

Received: December 4, 2008; Revised: February 27, 2009; Accepted: March 6, 2009

Published online September 28, 2009 in Wiley InterScience (www.interscience.wiley.com)

DOI: 10.1002/cncr.24607, www.interscience.wiley.com

Corresponding author: Christine Bouchardy, MD, MPH, Geneva Cancer Registry, 55 Boulevard de la Cluse, 1205 Geneva, Switzerland; Fax: (011)

41-22-379-4971; [email protected]

1Geneva Cancer Registry, Institute for Social and Preventive Medicine, University of Geneva, Geneva, Switzerland; 2Department of Community, Occu-

pational and Family Medicine, Faculty of Medicine, National University of Singapore, Singapore, Singapore; 3Urological Center, Grangettes Clinic,

Geneva, Switzerland; 4Piedmont Cancer Registry, Centro di Riferimento per l’Epidemiologia e la Prevenzione Oncologica, Torino, Italy; 5Radio-oncol-

ogy Service, Geneva University Hospitals, Geneva, Switzerland

We thank Stina Blagojevic for her technical and editorial help and Hyma Schubert and the registry team for their assistance during the

investigation.

This article is dedicated to the memory of Professor Charles-Henri Rapin, former president of the Association PROSCA (Prostate Cancer Patient Asso-

ciation), who conceived the idea for this study.

5556 Cancer December 1, 2009

Original Article

Cancer patients with low socioeconomic status (SES)have an increased risk of dying as a result of their diseasecompared with the risk in patients of higher SES.1,2 Thisassociation has been established for several other cancersites, such as the breast, cervix, colon, etc.3-6

SES plays an important role in prostate cancer.

Higher SES has been associated with more frequent PSA

screening,7,8 a lower stage of disease at diagnosis, and bet-

ter tumor differentiation.9,10 With regard to prostate can-

cer survival, results are not always consistent. Previous

studies have reported both positive association10,11 and

no association between SES and prostate cancer-specific

survival.12-14

Access inequalities to appropriate care and therapy

as well as differences in tumor biology are possible explan-

ations for survival differences between SES classes.

Inconsistent or inadequately measuring of socioeco-

nomic factors may affect conclusions regarding the rela-

tion between SES and health outcomes, and this appears

to be particularly true when other strong determinants of

survival, such as race/ethnicity, complicate establishing

the true association.15 Many previous studies regarding

SES and prostate cancer mortality are from North Amer-

ica, particularly from the United States, in which the area

code generally is used as surrogate of individual level of

SES.8,9,12,13,16,17 In addition, SES measures may have dif-

ferent meanings in different populations.15 Furthermore,

to our knowledge, few studies to date have evaluated fac-

tors impacting social disparities in prostate cancer mortal-

ity, such as differences in screening, disease stage at

diagnosis, tumor characteristics, and treatment.1,13,18

To the best of our knowledge, no studies are cur-

rently available regarding disparities and prostate cancer

mortality in Switzerland, a country with an extremely

well-developed healthcare system19,20 Medical insurance

is compulsory for all residents. The cost for this compul-

sory insurance package amounts to approximately 350

euros per month per person. The Swiss government covers

the complete medical insurance fees for indigent individu-

als (approximately 10%of the population) and covers

between 5% and 25% of the insurance fees for people

with low income (approximately 17% of the population).

The basic insurance package covers universal access to pre-

ventive and therapeutic care as well as pharmaceuticals. It

has been estimated that <3% of the population is not

insured.21 The main supplementary health insurance

policies, known as private and semi-private, cover addi-

tional benefits not covered by compulsory health insur-

ance (ie, free choice of hospital physician and superior

levels of hospital accommodation). Approximately 25%

of the population has 1 of the main forms of supplemen-

tary health insurance.

In the current study, we evaluated the effect of SES

on presentation, screening, tumor characteristics, treat-

ment, and survival in prostate cancer patients in a popula-

tion-based cohort of men diagnosed in Geneva,

Switzerland.

MATERIALS AND METHODS

We used data from the Geneva Cancer Registry (Geneva,

Switzerland), which records all incident cancers occurring

in the population of the canton (approximately 465,000

inhabitants in 2007). All hospitals, pathology laborato-

ries, and practitioners are requested to report all cancer

cases. Trained registrars systematically abstract data from

medical and laboratory records. Physicians regularly

receive questionnaires to obtain missing data. Recorded

data include sociodemographic variables, method of

detection, prostate-specific antigen (PSA) level at the time

of diagnosis, tumor characteristics (including histology,

differentiation based on tumor grade, and Gleason score),

stage at diagnosis according to the TNM classification,

lymph node status, treatment, survival status, and cause of

death. The registry regularly assesses survival data. The

index date was the date of confirmation of diagnosis or

the date of hospitalization if it preceded the diagnosis and

pertained to the disease. Active follow-up is performed

yearly using the files of the Cantonal Population Office,

which is in charge of registration of the resident popula-

tion. Trained registrars establish cause of death by system-

atically consulting clinical records, interpreting

questionnaires completed by the patient’s physician, or

both.

Between January 1, 1995, and December 31, 2005,

a total of 2865 men were diagnosed with prostate cancer

in the resident population. We excluded 76 men with

prostate cancer diagnosed at the time of death and 51 men

for whom information regarding SES was missing. The

final cohort included 2738 patients.

The Geneva Cancer Registry systematically retrieves

the patient’s most recent occupation from the files of the

Prostate Cancer and Socioeconomic Status/Rapiti et al

Cancer December 1, 2009 5557

Cantonal Population Office. We used the classification of

vital statistics, which includes 12 major groups subdivided

into 40 submajor groups and 130 minor groups.22 Occupa-

tional subgroups were classified into SES indicators on 7

levels based on the Social Classes of the British Registrar

General.23 For the purpose of the current study, we

regrouped SES into 3 levels only: low (manual employees

and skilled and unskilled workers, including farmers), mid-

dle (nonmanual employees and clerks), and high (professio-

nals, executives, administrators, and entrepreneurs).24

For this study, variables of interest were age, nation-

ality (Swiss vs other), period of diagnosis (1995-1999 vs

2000-2005), and sector of care (public vs private). We

classified the method of detection as screening (by PSA

with or without digital rectal examination) and other

(including fortuitous discovery during treatment for other

diseases and after symptoms). Tumor stage was based on

the TNM classification system. We used pathologic stage,

or when absent, clinical stage. Tumors were classified as

T1 (clinically unapparent tumor not palpable or visible by

imaging), T2 (tumor confined within the prostate), T3

(tumor extends through the prostate capsule with or with-

out invasion of the seminal vesicles), T4 (tumor is fixed or

invades adjacent structures), and TX (unknown). Lymph

node invasion was classified as N0 (no regional lymph

node metastasis), N1 (regional lymph node metastasis),

and NX (unknown) and distant metastasis as M0 (absent),

M1 (present), or MX (unknown). Differentiation was

classified as grade 1 (well-differentiated: Gleason score of

2-4), Grade 2 (moderately differentiated: Gleason score of

5-6), Grade 3 to 4 (poorly differentiated, undifferenti-

ated: Gleason score of 7-10), and unknown.25

Stage was classified in 5 groups: stage I (T1a and N0

and Gleason score 1), stage II (T1a and N0 and Gleason

score 2-4; or T1a or T1b, or T1 or T2 and N0 and any

Gleason score), stage III (T3 and N0 and any Gleason

score), stage IV (T4 and N0 and any Gleason score, or any

T and N1 and any Gleason score, or any T and any N and

M1 and any Gleason score), and unknown.26

Treatments given during the first 6 months after a

diagnosis of prostate cancer included prostatectomy (radi-

cal, retropubic, or perineal), hormonal treatment (surgical

or hormonal castration), and external radiotherapy (with

or without hormonal therapy). Brachytherapy was not

used during the study period. Watchful waiting was com-

prised of active follow-up of the patient and treatment

only in the case of disease progression. We did not con-

sider transurethral prostate resection as surgical treatment

for prostate cancer.

Differences between SES levels were tested with the

chi-square test. Follow-up of patients was completed on

December 31, 2006. We calculated cumulative disease-

specific survival rates by Kaplan-Meier analysis and tested

survival differences with the log-rank test. We evaluated

the impact of SES on disease-specific survival by multivar-

iate Cox proportional hazards analysis, adjusting for age

(in continuous), period of diagnosis (in continuous),

method of detection, lymph node status, tumor stage, dif-

ferentiation, sector of care, and treatment. To evaluate to

what extent patient and tumor characteristics, method of

detection, treatment, and sector of care explained the soci-

oeconomic differences in prostate cancer survival, we

gradually entered the factors in the Cox model. Analyses

were performed using SPSS statistical software (version

15; SPSS Inc, Chicago, Ill). All P values <.05 were con-

sidered statistically significant.

RESULTS

Table 1 shows the demographic and tumor characteristics

of the study population. There were 839 men of low SES

(30.6%), 1173 of middle SES (42.8%), and 726 of high

SES (26.5%). Men of low SES were older at the time of

diagnosis, more likely to be foreigners, were less fre-

quently diagnosed by screening, and underwent treatment

more often in the public sector. They presented with a

higher tumor grade and more advanced stage of disease at

the time of diagnosis than men of middle or high SES.

They had also less information regarding tumor character-

istics and stage of the disease. However, the proportion of

patients with an unknown Gleason score/grade was high:

approximately 10%, for all the SES levels. Men of low

SES underwent prostatectomy less often and were more

frequently managed by watchful waiting. The treatment

differences by SES also remained significant when stratify-

ing by stage of disease at diagnosis. In particular, in the

group of patients with early stage disease, the proportion

of men who underwent surgery was 56% in the high SES

group, 52% in the middle SES group, and 47% in the low

SES group (P value for Pearson chi-square¼ .023).

After a median follow-up of 3.9 years (range, 4 days-

12 years), 1730 patients (63%) were still alive, 840 (31%)

Original Article


had died (385 of prostate cancer), and 168 (6.1%) were lost

to follow-up. The 5-year cumulative survival rate for pros-

tate cancer was 88% (95% confidence interval [95% CI],

84-92%) amongmen of high SES, 84% (95%CI, 82-86%)

among men of middle SES, and 77% (95% CI, 73-81%)

among men of low SES (P value for log-rank test <.001).

Subgroup analysis by stage indicated that SES differences in

prostate cancer mortality were present only among patients

with advanced stage disease; among those patients diagnosed

at stage III to stage IV, the 5-year survival rates of men in the

high, middle, and low SES groups were 53% (95% CI, 41-

65%), 39% (95% CI, 29-49%), and 27% (95% CI, 17-

37%), respectively (P value for log-rank test ¼ .019). No

differences were observed for patients with stage I to II dis-

ease (P value for log-rank test¼ .124) (Fig. 1).

Unadjusted Cox analysis demonstrated that patients

in the low SES group had a significantly higher risk of

death from prostate cancer than patients in the high SES

group (crude hazards ratio [HR], 2.0; 95% CI, 1.5-2.6

[P< .001]) (Table 2).

After adjustment for age, sector of care, method of

detection, stage of disease, tumor grade, and treatment

Table 1. Patient and Tumor Characteristics, Method of Detection, Sector of Care, and TreatmentsAccording to Socioeconomic Status AmongMenWith Prostate Cancer (Geneva 1995–2005)

Characteristics Socioeconomic Status P

Low Middle HighNo. (%) No. (%) No. (%)

All patients 839 (30.6) 1173 (42.8) 726 (26.5)

Mean age at diagnosis, y 71.3 69.3 68.9 .000

Nationality .019

Swiss 448 (61.7) 795 (67.8) 535 (63.8)

Other 278 (38.3) 378 (32.2) 304 (36.2)

Period of diagnosis .268

1995-1999 290 (39.9) 425 (36.2) 316 (37.7)

2000-2005 436 (60.1) 748 (63.8) 523 (62.3)

Method of detection .000

Screening 351 (48.3) 724 (61.7) 529 (63.1)

Symptoms 207 (28.5) 265 (22.6) 177 (21.1)

Other 168 (23.1) 184 (15.7) 133 (15.9)

Sector of care .000

Private 368 (50.7) 801 (68.3) 635 (75.7)

Public 358 (49.3) 372 (31.7) 204 (24.3)

Stage of disease .006

I-II 322 (44.4) 613 (52.3) 435 (51.8)

III 177 (24.4) 282 (24.0 201 (24.0)

IV 146 (20.1) 176 (15.0) 125 (14.9)

Unknown 81 (11.2) 102 (8.7) 78 (9.3)

Lymph node invasionNo 360 (49.6) 689 (58.7) 512 (61.0) .000

Yes 44 (6.1) 71 (6.1) 56 (6.7)

Unknown 322 (36.7) 413 (35.2) 271 (32.3)

Gleason grade .040

Well-differentiated (Gleason 2-4) 51 (7.0) 887 (7.4) 68 (8.1)

Moderately differentiated (Gleason 5-6) 290 (39.9) 549 (46.8) 395 (47.1)

Poorly or undifferentiated (Gleason 7-10) 306 (42.1) 428 (36.5) 302 (36.0)

Unknown 79 (10.9) 109 (9.3) 74 (8.8)

Type of treatment .001

Prostatectomy 253 (34.8) 474 (40.4) 382 (45.5)

Radiotherapy 141 (19.4) 246 (21.0) 141 (16.8)

Hormonal therapy 100 (13.8) 116 (9.9) 79 (9.4)

Watchful waiting 164 (22.6) 245 (20.9) 180 (21.5)

Other 68 (9.4) 92 (7.8) 57 (6.8)



(all independent and significant determinants of prostate

cancer-specific mortality), low SES was no longer found

to be significantly associated with prostate cancer-specific

mortality (adjusted HR, 1.2; 95%CI, 0.8-1.6) (Table 2).

Table 3 shows the modification of prostate cancer-

specific mortality risk after stepwise adjustment for other

prognostic factors. The excess mortality risk associated

with a low SES diminished but remained statistically sig-

nificant after adjustment for sociodemographic patient

characteristics such as age, period of diagnosis, and

nationality, and for tumor characteristics such as stage and

grade. Compared with men of high SES, the multiad-

justed HR was 1.3 for men of middle SES (95% CI, 0.9-

1.7) and 1.4 for men of low SES (95% CI, 1.0-2.0) (P ¼.031). After further adjustment for method of detection,

the risk of death from prostate cancer for patients of low

SES was still higher than for patients of high SES,

although the difference was not significant (HR, 1.4; 95%

CI, 1.0-1.9 [P¼ .054]). Adjustment for type of treatment

and sector of care further reduced the excess risk of mor-

tality among patients of low SES (Table 3). Subgroup

analysis by stage confirmed that the excess mortality was

limited to patients with stage III through IV disease, with

a crude HR of 1.8 (95% CI, 1.3-2.5; P ¼ .001) for the

FIGURE 1. The 5-year overall prostate cancer-specific cumulative survival according to socioeconomic level is shown (Geneva,

1995-2005) in (a) the overall cohort, (b) patients with stage I through stage II prostate cancer, and (c) patients with stage III

through stage IV prostate cancer.

Original Article


low SES group. Then again, adjustment for tumor and

patient characteristics, screening, sector of care, and treat-

ment lowered the risk, which then became not statistically

significant (HR, 1.2; 95%CI, 0.8-1.7 [P¼ .401]).

DISCUSSION

Despite the high quality of and widespread access to med-

ical care in Geneva, Switzerland, the results of the current

study demonstrate that prostate cancer patients of low

SES have a 2-fold increased risk of death from their dis-

ease compared with prostate cancer patients of high SES.

Socioeconomic discrepancies in prostate cancer mortality

were limited to patients with an advanced stage of disease

at the time of diagnosis. However, differences in PSA

screening, tumor characteristics, treatment, and sector of

care almost completely explain the increased mortality

observed among patients of low SES.

Table 2. Unadjusted and Adjusted Prostate Cancer-Specific Mortality Risk According to Patient Characteristics, Period,Sector of Care, and Tumor Characteristics (Geneva 1995–2005)

UnadjustedHR

95% CI MultiadjustedHR*

95% CI¶

Age at diagnosis (continuous) 1.11y 1.10-1.12 1.03y 1.0-1.1

Socioeconomic statusHigh 1.0z 1.0zMiddle 1.3 1.0-1.7 1.1 0.8-1.6

Low 2.0y 1.5-2.6 1.2 0.9-1.7

NationalitySwiss 1.0z 1.0zOther 1.8y 1.4-2.4 1.2 0.9-1.6

Period of diagnosis (continuous) 0.91y 0.87-0.94 1.0 0.94-1.02

Method of detectionScreening 1.0z 1.0zSymptoms 8.8y 6.5-12 3.1y 2.2-4.4

Other 5.3y 3.7-7.5 2.3y 1.5-3.5

Sector of carePrivate 1.0z 1.0zPublic 2.7y 2.1-3.3 1.5§ 1.1-2.0

Stage of diseaseI-II 1.0z 1.0zIII 1.9§ 1.2-3-1 1.3 0.8-2.2

IV 26y 18-37 7.0z 4.6-11

Gleason gradeWell-differentiated (Gleason 2-4) 1.0z 1.0zModerately differentiated (Gleason 5-6) 1.9 0.7-5.3 3.4| 1.0-11

Poorly or undifferentiated (Gleason 7-10) 11y 4.1-29 8.1z 2.5-26

Unknown 29y 11-79 12z 3.6-38

Type of treatmentProstatectomy 1.0z 1.0zRadiotherapy¶ 1.7| 1.0-2.8 1.6 0.9-2.7

Hormonal therapy 4.7y 3.1-7.1 2.6z 1.6-4.1

Watchful waiting 17y 11-25 2.6z 1.7-4.2

Other 11y 7.1-17 1.7| 1.1-2.8¶

HR indicates hazards ratio; 95% CI, 95% confidence interval.

*Multivariate analysis adjusted for age, socioeconomic status, nationality, period of diagnosis, method of detection, sector of care, clinical stage of disease,

grade, and type of treatment.

yP < .001.

zReference value.

§P < .01.

|P < .05.

¶With or without hormonal therapy.



In Geneva, prostate cancer patients of low SES were

older, and presented with a higher tumor grade and more

advanced stage of disease at the time of diagnosis than

patients of high SES. This might be the consequence of a

lower awareness regarding PSA screening and prostate

cancer warning signs among patients of low SES. How-

ever, less health conscious behavior, in terms of the under-

utilization of preventive services, may have played a role as

well. Prostate tumors can be detected early through PSA

screening, and it has been well documented that SES

affects access and utilization of PSA screening.7,8,16

Indeed, in our study, approximately 63% of prostate can-

cers diagnosed among men of high SES are detected

through screening compared with 48% for men of low

SES. The results of the current study are consistent with

previous studies reporting that men from higher social

classes are more likely to be diagnosed with localized dis-

ease8,10,13,27 and that lower SES is associated with a lower

likelihood of undergoing PSA testing.7 Although evidence

that prostate cancer deaths are reduced by PSA screening

is insufficient, its use may still serve as a marker of delivery

of care.

We also observed a high proportion of patients with

unknown Gleason score/grade, who had an extremely

higher risk of dying from prostate cancer. These patients

were older (>52% were aged �80 years at the time of di-

agnosis) and tended not to receive surgery as treatment for

their prostate cancer (only 6.5% underwent surgery,

whereas 49% were managed by watchful waiting and

33% by hormonal therapy only). This finding reveals a

tendency not to perform a biopsy or initiate an aggressive

treatment because of the older age of the patient and pos-

sible presence of comorbidities, which in turn may explain

the extremely high risk of dying from prostate cancer

noted in this population. The majority of these cases were

relative to the period 1995 through 2000 (63.3%) and,

with time, we observed a trend toward a decrease in the

proportion of patients without available tumor grade.

In the current study, men of low SES tended to

receive treatment with curative intent, such as surgery or

radiotherapy, less often and were more often managed by

watchful waiting. The differences in treatment were not

explained by differences in the stage of disease at the time

of diagnosis, because they persisted when considering

only patients with early stage prostate cancer. This result

confirms the findings of other studies reporting that menTable

3.Risk(H

R)ofDyingasaResultofPro

state

CancerAccord

ingto

Socioeconomic

Statu

sAfterPro

gressiveAdjustmentonOth

erPutativeExplanato

ryFacto

rs(G

enevaCancerRegistry,1995–2005)

Socioeconomic

Level

No.

Deaths

Unadjusted

HR

HR

Adjusted

forAge,Period

ofDiagnosis,

andNationality

HR

Additionally

AdjustedforStage

andGradeofDisease

HR

Additionally

Adjustedfor

Method

ofDetection

HR

Additionally

Adjustedfor

SectorofCare

andTreatm

ent

High*

839

71

11

11

1

Middle

1173

126

1.3

(1.0-1.7)

1.2

(0.9-1.6)

1.3

(0.9-1.8)

1.3

(0.9-1.8)

1.1

(0.8-1.5)

Low

726

112

2.0y(

1.5-2.6)

1.5z(

1.1-2.0)

1.4z(

1.0-2.0)

1.4

(1.0-1.9)

1.2

(0.8-1.6)

PvalueforWald

test

.000

.043

.094

.141

.667

HR

indicateshaza

rdsratio.

*Referencevalue.

yP<.001.

zP<.05.

Original Article


with lower SES were less likely to be treated at all, and

that men with a lower educational level were less likely to

undergo prostatectomy and more likely to receive

radiotherapy.17,28,29

With regard to prostate cancer-specific survival and

SES, we found an 11% unadjusted survival difference

between men of low versus high SES. The excess mortality

risk associated with low SES remained significant, even af-

ter adjusting for tumor characteristics at diagnosis. The

excess mortality risk disappeared when we introduced

method of detection, sector of care, and treatment into

the Cox model, suggesting that SES differences in prostate

cancer-specific mortality are largely attributable to socioe-

conomic differences in diagnosis and treatment. Although

the evidence base for the benefits of screening and treat-

ment options is not yet fully developed for prostate can-

cer, PSA screening with or without digital rectal

examination and curative treatments such as prostatec-

tomy and radiotherapy have been shown to be major

determinants of outcome.13,30-33 Lead time and length

time biases linked to early detection through PSA screen-

ing may partially explain the survival advantage observed

among patients with a high SES. However, we found that

the differences based on SES in prostate cancer mortality

were limited to patients with advanced disease, for whom

the impact of such biases is definitively less strong; on the

contrary, the choice of treatment most likely plays a more

important role. One likely reason why the effect of social

inequalities in treatment is more important in patients

with later stage disease than in those with early stage dis-

ease is because of the much higher mortality burden of

stage III through IV prostate cancers.

The association between SES and prostate cancer sur-

vival has been demonstrated in previous studies.10-14 In the

majority of them, SES remained an independent determi-

nant of mortality even after adjustment for clinical and

treatment factors, indicating a residual effect not explained

by differences in the healthcare received.3,30,33,34 However,

a great heterogeneity exists among the SES indicators used

and the variables chosen to adjust for confounding and that

may explain the divergence with the results of the current

study. Furthermore, in studies in which access to healthcare

was considered to be equivalent among men of different

SES, no association has been observed.12,14

The results of the current study are derived from

population-based cancer registry data covering all incident

cases of prostate cancer in the canton of Geneva. No

inclusion restrictions were made. The follow-up was pro-

spectively determined and complete for 94% of the study

population, and cause of death was ascertained for 94% of

the persons who died. SES was assessed at the individual

level. Furthermore, we had complete information regard-

ing therapy. In addition, the study population was rela-

tively uniform in terms of ethnicity, leaving little room for

confounding by ethnicity.

We realize that, despite detailed information regard-

ing patient and tumor characteristics and treatment, there

is still room for residual confounding associated with

unrecorded prognostic factors, such as surgical margin sta-

tus, type and dose of radiotherapy, and the patient’s com-

pliance with treatment. Evidence also indicates that a

single measure of SES is of limited information and that

other unmeasured socioeconomic factors may affect con-

clusions regarding the particular health outcome and pop-

ulation of interest.15 The patient’s most recent occupation

as registered at the Cantonal Population Office was the

only measure of SES available for the current study and,

although collected at an individual level, it may not be suf-

ficient to capture the multidimensional nature of SES.

However, studies conducted in Europe have repeatedly

found strong correlations between occupational status

using a similar classification as ours and diverse health

indicators, even after controlling for other commonly

used socioeconomic measures such as education and

income.15 In addition, we had no information available

regarding comorbidities, which could influence not only

general but also prostate cancer-specific mortality, because

comorbidities may influence choice of treatment, compli-

ance, or host response to tumor. However, adjustment for

comorbidities in previous large, population-based studies

resulted in nearly no differences in HR estimates of overall

mortality.13

In conclusion, we observed strong disparities

with regard to access to care and treatment of prostate

cancer between socioeconomic groups in a country

that has 1 of the best equipped healthcare systems in

Europe19 and compulsory basic insurance for the

entire population. These differences may explain the

higher prostate cancer-specific mortality risk associ-

ated with low SES. Policies ensuring a more equitable

access to screening and treatment are needed to elimi-

nate these disparities.



Conflict of Interest Disclosures

The authors made no disclosures.

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Original Article


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Impact of socioeconomic status on prostate cancer diagnosis, treatment, and prognosis

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