Stage 4 Ovarian Cancer
Relation between socioeconomic status and tumour stage in patients with breast, colorectal, ovarian, and lung cancer: results from four national, population based studiesDavid H Brewster Although there is evidence that patients with cancer from deprived communities in Scotland might present with more advanced disease,[1-3] this finding has not been replicated in every study.[4] Using data from four population based audits, we investigated whether there is any relation between socioeconomic status and tumour stage at presentation in patients with breast, colorectal, ovarian, and lung cancer.
Participants, methods, and results
For each audit potential study populations were identified from the Scottish Cancer Registry, and data were abstracted from medical records. The years of diagnosis for patients with breast, colorectal, ovarian, and lung cancer were 1993, 1993, 1992-4, and 1995, respectively.
The staging details examined were: pathological size, pathological nodal status, and metastatic status for breast cancers; Dukes' stage for colorectal cancers; Federation Internationale de Gynecologie et d'Obstetrique stage for ovarian cancers; and a simple extent of disease classification based on clinical findings or investigations for lung cancers (as only 11% of cases had surgical resection), or both.
Medical records were available for 2518 patients with breast cancer, 2778 with colorectal cancer, 1387 with ovarian cancer, and 3855 with lung cancer, representing more than 90% of potentially eligible cases for each of the four cancer sites. A higher proportion of records was unobtainable for deprived than for affluent patients with lung cancer (11.7% v 7.0%, P [is less than] 0.001) (see table on website). No significant differences were found in availability of medical records by deprivation grouping for the other cancers.
Relation between socioeconomic status and tumour stage in patients with
breast, ovarian, colorectal, and lung cancer. Values are numbers
(percentages)
Deprivation group(*)
Affluent Middle
Breast cancer([dagger]) n=548 n=1605
Tumour size (mm):
0-20 271 (49.5) 730 (45.5)
21-50 124 (22.6) 409 (25.5)
>50 14 (2.6) 49 (3.1)
Unknown 139 (25.4) 417 (26.0)
Significance [chi square]=9.89, df=6, P=0.13
Node status:
Positive 144 (26.3) 467 (29.1)
Inadequate negative
sample([double dagger]) 58 (10.6) 178 (11.1)
Negative([sections]) 208 (38.0) 523 (32.6)
Unknown 138 (25.2) 437 (27.2)
Significance [chi square]=7.79, df=6, P=0.25
Metastatic status at presentation
M0 517 (94.3) 1492 (93.0)
M1 31 (5.7) 113 (7.0)
Significance [chi square]=3.89, df=2, P=0.14
Colorectal cancer([dagger]) n=590 n=1734
Dukes' stage:
A 61 (10.3) 149 (8.6)
B 202 (34.2) 576 (33.2)
C 130 (22.0) 415 (23.9)
`D' 117 (19.8) 377 (21.7)
Unknown 80 (13.6) 217 (12.5)
Significance [chi square]=4.74, df=8, P=0.79
Ovarian cancer([dagger]) n=304 n=856
Federation Internationale de
Gynecologie et d'Obstetrique
stage:
I 73 (24.0) 191 (22.3)
II 30 (9.9) 77 (9.0)
III 126 (41.4) 388 (45.3)
IV 51 (16.8) 131 (15.3)
Unknown 24 (7.9) 69 (8.1)
Significance [chi square]=14.96, df=8, P=O.06
Lung cancer n=534 n=2371
Clinical stage:
Localised 152 (28.5) 758 (32.0)
Regional 134 (25.1) 628 (26.5)
Distant 183 (34.3) 726 (30.6)
Unknown 65 (12.2) 259 (10.9)
Significance [chi square]=13.52, df=6, P=0.04
Deprivation
group(*)
Deprived Total
Breast cancer([dagger]) n=364 n=2517
Tumour size (mm):
0-20 166 (45.6) 1167 (46.4)
21-50 109 (29.9) 642 (25.5)
>50 13 (3.6) 76 (3.0)
Unknown 76 (20.9) 632 (26.1)
Significance [chi square]=9.89, df=6, P=0.13
Node status:
Positive 111 (30.5) 722 (28.7)
Inadequate negative
sample([double dagger]) 31 (8.5) 267 (10.6)
Negative([sections]) 128 (35.2) 859 (34.1)
Unknown 94 (25.8) 669 (26.6)
Significance [chi square]=7.79, df=6, P=0.25
Metastatic status at presentation
M0 331 (90.9) 2340 (93.0)
M1 33 (9.1) 177 (7.0)
Significance [chi square]=3.89, df=2, P=0.14
Colorectal cancer([dagger]) n=453 n=2777
Dukes' stage:
A 38 (8.4) 248 (8.9)
B 156 (34.4) 934 (33.6)
C 97 (21.4) 642 (23.1)
`D' 101 (22.3) 595 (21.4)
Unknown 61 (13.5) 358 (12.9)
Significance [chi square]=4.74, df=8, P=0.79
Ovarian cancer([dagger]) n=226 n=1386
Federation Internationale de
Gynecologie et d'Obstetrique
stage:
I 33 (14.6) 297 (21.4)
II 14 (6.2) 121 (8.7)
III 108 (47.8) 622 (44.9)
IV 44 (19.5) 226 (16.3)
Unknown 27 (11.9) 120 (8.7)
Significance [chi square]=14.96, d1=8, P=O.06
Lung cancer n=950 n=3855
Clinical stage:
Localised 342 (36.0) 1252 (32.5)
Regional 214 (22.5) 976 (25.3)
Distant 295 (31.1) 1204 (31.2)
Unknown 99 (10.4) 423 (11.0)
Significance [chi square]=13.52, df=6, P=0.04
(*) Patients were assigned to a 1991 census derived Carstairs
deprivation category based on their postcode sector of residence at
diagnosis. Carstairs deprivation categories: 1 and 2, affluent; 3,
4, and 5, middle; 6 and 7, deprived.
([dagger]) Deprivation score could not be assigned for one case.
([double dagger]) Represents 1, 2, 3, or unknown number of nodes
sampled, all negative.
([sections]) Represents 4 or more nodes sampled or axillary clearance,
all negative.
The table shows the distributions of variables for tumour staging by cancer site and deprivation grouping. P values for associations between the staging variables and deprivation were similar when unknown stages were excluded. We found no evidence that patients from deprived communities were likely to present with more advanced disease for breast or colorectal cancer. For ovarian cancer there was a possibility that deprived patients may have more advanced disease (see table); however, deprived patients with lung cancer were more likely to present with localised disease (see table). Multivariate analyses, performed using log linear modelling, showed no evidence of age dependent relations between stage of disease and deprivation. The four age groups used for these analyses differed by cancer site because they were predefined by different specialist groups--for example, the breast cancer specialists included a category for screening age group (50-64 years).
Comment
We found no consistent evidence that patients from deprived communities present with more advanced disease for breast, colorectal, ovarian, or lung cancer. Despite the introduction of breast screening and differential uptake by socioeconomic status,[5] our results for breast cancer remain similar to those of Carnon et al.[4] However, another recent but smaller study from the west of Scotland found that women from deprived areas were more likely to present with locally advanced or metastatic disease.[3] Our result for colorectal cancer conflicts with those of a study from Tayside, although the latter was based on cases for which there was a record of disease, and so not population based, and excluded patients with distant metastases.[2] The result for ovarian cancer was of borderline significance, although patients with stage unknown had a generally worse prognosis than those with stage IV disease, presumably reflecting inoperability. The greater likelihood of deprived patients with lung cancer presenting with localised disease could be an artefact resulting from differential availability of medical records across the socioeconomic groupings or, owing to comorbidity, less intensive investigation of these patients leading to less accurate data for staging. Alternatively, it might reflect a lower threshold for investigation and referral in patients from deprived communities presenting with suspicious symptoms, because they are more likely to be current smokers. Further research is needed to investigate the contribution of tumour, host, and treatment related factors to outcome.
We thank Professor Colin McArdle and his surgical colleagues in the west of Scotland who allowed their data from a previous audit to be used in the Scottish Cancer Therapy Networks national audit of colorectal cancer and the many other clinicians in Scotland who contribute to the network's audits.
Contributors: DHB initiated the analysis, but all the authors were involved in specifying the analysis and interpretation of the results. CST and DJH carried out the analyses. DHB wrote the first draft of the manuscript, which was modified to incorporate comments from all the other authors; he will act as guarantor.
Funding: The Scottish Cancer Therapy Network is funded by grants from the Clinical Resource and Audit Group and the Chief Scientist Office, both of the Scottish Executive Health Department. The views expressed, however, are those of the authors.
Competing interests: None declared.
[1] Lamont DW, Symonds RP, Brodie MM, Nwabineli NJ, Gillis CR. Age, socioeconomic status and survival from cancer of the cervix in the West of Scotland 1980-87. Br J Cancer 1993;67:351-7.
[2] Ionescu MV, Carey F, Tait IS, Steele RJC. Socioeconomic status and stage at presentation of colorectal cancer. Lancet 1998;352:1439.
[3] Macleod U, Ross S, Gillis C, McConnachie A, Twelves C, Watt GCM. Socio-economic deprivation and stage of disease at presentation in women with breast cancer. Ann Oncol 2000;11:105-7.
[4] Carnon AG, Ssemwogerere A, Lamont DW, Hole DJ, Mallon EA, George WD, et al. Relation between socioeconomic deprivation and pathological prognostic factors in women with breast cancer. BMJ 1994;309:1054-7.
[5] McLaren GL, Bain MRS. Deprivation and health in Scotland: insights from NHS data. Edinburgh: ISD Scotland, 1998.
(Accepted 13 December 2000)
Scottish Cancer Intelligence Unit, Information and Statistics Division, Trinity Park House, Edinburgh EH5 3SQ
David H Brewster director of cancer registration in Scotland
Catherine S Thomson senior statistician
Roger J Black head
Paul L Stroner coordinator of the Scottish Cancer Therapy Network
West of Scotland Cancer Surveillance Unit, Department of Public Health, University of Glasgow, Glasgow G12 8RZ
David J Hole deputy director
Charles R Gillis director
Correspondence to: D H Brewster David.Brewster@ isd.csa.scot.nhs.uk
COPYRIGHT 2001 British Medical Association
COPYRIGHT 2001 Gale Group
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