Session Information
Session Type: ACR Poster Session B
Session Time: 9:00AM-11:00AM
Background/Purpose:
Patients with rheumatoid arthritis (RA) have been shown to have an increased risk of developing malignancies. This study was undertaken to determine the incidence and pattern of malignancy in RA patients and identify risk factors of malignancy among patients with RA.
Methods:
Patients from the TTSH RA Registry were followed up longitudinally and those who developed malignancies from 2001 to 2013 after the onset of RA were identified. Age-standardised rates (ASRs) of various cancers were analyzed and compared with the Singapore Cancer Registry data. Risk factors for developing malignancy, including demographics, disease characteristics and treatment history, were analyzed using Chi-squared test and student’s t test.
Results:
Of the 1,134 patients in the registry, 81 patients developed malignancies at a mean interval of 15.1 (SD 9.7) years after the onset of RA. The mean age of the 81 patients was 65.9 (SD 10.8) years, of which 61 (75.31%) were females and 69 (85.19%) were Chinese. There were 70 (86.4%) with solid-organ tumours and 11 (13.6%) haematological malignancies.
The ASR of cancer in RA patients was 310.3 for males and 232.5 for females per 100,000 person-years, compared with 229.3 (95%CI 226.5-232) for males and 218.3 (95%CI 213.8-216.3) for females in the general population. By cancer type, there is an increased risk of lung cancer, lymphoid neoplasms and stomach cancer in RA compared with the general population.
The risks factors for developing malignancy (p<0.05) include male gender, non-Indian ethnicity, onset of RA at an older age, untreated RA and higher disease activity.
Conclusion:
The incidence of solid-organ malignancies was higher than hematological malignancies, unlike that in the literature. The overall risk of malignancy is higher in RA patients. Chronic inflammation from RA is associated with increased risk of malignancy.
Table 1
|
Crude Rates (CR) and Age standardize rates (ASR) of specific cancer types among the general population and rheumatoid arthritis cohort |
||||||||||
|
Gender |
Maligancy |
Singapore general population (2009-2013) |
1106 RA patients (2001-2013) |
|||||||
|
Cancer Types |
Observed cancer cases |
CR |
ASR |
95% CI for ASR |
total RA |
Observed cancer cases |
Cancer % |
CR |
ASR |
|
|
Male |
All cancers |
28520 |
305.2 |
229.3 |
(226.5, 232) |
177
|
20 |
100 |
1194.10 |
310.30 |
|
Lung |
4318 |
46.2 |
34 |
(33, 35) |
8 |
40 |
477.64 |
148.63 |
||
|
Lymphoid neoplasms |
1890 |
20.2 |
16.7 |
(15.9, 17.5) |
3 |
15 |
179.11 |
38.91 |
||
|
Stomach |
1414 |
15.1 |
11.1 |
(10.5, 11.7) |
3 |
15 |
179.11 |
36.35 |
||
|
Kidney & other urinary |
1035 |
11.1 |
8.1 |
(7.6, 8.6) |
2 |
10 |
119.41 |
29.45 |
||
|
Colo-rectum |
4935 |
52.8 |
38.7 |
(37.6, 39.8) |
1 |
5 |
59.7 |
15 |
||
|
Prostate |
3456 |
37 |
28.1 |
(27.1, 29) |
1 |
5 |
59.7 |
10.01 |
||
|
Nasopharynx |
1122 |
12 |
8.4 |
(7.9, 8.9) |
1 |
5 |
59.7 |
19.44 |
||
|
Female |
All cancers |
30237 |
314.6 |
213.8 |
(213.8, 216.3) |
928
|
61 |
100 |
665.00 |
232.52 |
|
Colo-rectum |
3996 |
41.6 |
26.3 |
(25.5, 27.1) |
11 |
18.03 |
119.92 |
32.83 |
||
|
Female Breast |
8867 |
92.2 |
63.4 |
(62.1, 64.8) |
10 |
16.39 |
109.02 |
46.68 |
||
|
Lymphoid neoplasms |
1323 |
13.8 |
10.8 |
(10.2, 11.5) |
7 |
11.47 |
76.31 |
31.59 |
||
|
Lung |
2294 |
23.9 |
15 |
(14.4, 15.6) |
6 |
9.84 |
65.41 |
27.46 |
||
|
Skin, including Melanoma |
1321 |
13.7 |
8.4 |
(7.9, 8.8) |
5 |
8.2 |
54.51 |
15.82 |
||
|
Cervix uteri |
952 |
9.9 |
6.8 |
(6.4, 7.3) |
5 |
8.2 |
54.51 |
21.76 |
||
|
Stomach |
1089 |
11.3 |
6.9 |
(6.5, 7.3) |
3 |
4.92 |
32.7 |
7.7 |
||
|
Corpus uteri |
1922 |
20 |
13.8 |
(13.2, 14.4) |
2 |
3.28 |
21.8 |
6.45 |
||
|
Pancreatic |
|
|
|
|
2 |
3.28 |
21.8 |
8 |
||
|
Thyroid |
1076 |
11.2 |
8.4 |
(7.8, 8.9) |
2 |
3.28 |
21.8 |
8.01 |
||
|
Ovary, etc. |
1646 |
17.1 |
12.5 |
(11.8, 13.1) |
1 |
1.64 |
1.64 |
2.78 |
||
Note: Both the ASR for Singapore general population and our RA cohort were standardized to Segi’s world population age structure. CR; ASR: Per 100,000 person-year
Table 2
|
Demographics, disease characteristics and treatment history of patients without malignancy and those who develop malignancy |
|||||
|
|
|
Total No. of Patients n=1106 (%) |
No. of Patients without maligancy n=1025 (%) |
No. of Patients with maligancy after 1st study entry n=81 (%) |
Univariate test p-value (t-test or chi2) |
|
Demographics |
|||||
|
Age at RA onset (yrs) |
mean (SD) |
45.03 (13.40) |
44.58 (13.20) |
50.77 (14.59) |
0.0001 |
|
Age at RA diagnosis (yrs) |
mean (SD) |
47.31 (13.69) |
46.74 (13.55) |
54.43 (13.52) |
<0.0001 |
|
Duration of RA onset to RA diagnosis (mths) |
mean (SD) |
27.34 (66.63) |
26.02 (64.86) |
43.96 (84.61) |
0.0196 |
|
Gender |
Male |
177 (16.02) |
157 (15.33) |
20 (24.69) |
0.0390 |
|
Ethnicity |
Chinese |
849 (76.83) |
780 (76.17) |
69 (85.19) |
0.1350 |
|
|
Malay |
96 (8.69) |
91 (8.89) |
5 (6.17) |
|
|
|
Indian |
129 (11.67) |
125 (12.21) |
4 (4.94) |
|
|
|
Others |
31 (2.81) |
28 (2.73) |
3 (3.70) |
|
|
Chinese |
Non-Chinese |
256 (23.17) |
244 (23.83) |
12 (14.81) |
0.0750 |
|
|
Chinese |
849 (76.83) |
780 (76.17) |
69 (85.19) |
|
|
Indian |
Non-Indian |
976 (88.33) |
899 (87.79) |
77 (95.06) |
0.0480 |
|
|
Indian |
129 (11.67) |
125 (12.21) |
4 (4.94) |
|
|
Education |
<= primary |
489(44.99) |
448(44.53) |
41(50.62) |
0.2980 |
|
|
>=secondary |
598(55.01) |
558(55.47) |
40(49.38) |
|
|
Smoking |
Ever |
150 (13.56) |
134 (13.07) |
16 (19.75) |
0.0930 |
|
Disease characteristics |
|||||
|
Rheumatoid Factor |
Positive |
797 (77.15) |
744 (77.66) |
53 (70.67) |
0.1980 |
|
Anti-CCP |
Positive |
548 (74.36) |
513 (74.56) |
35 (71.43) |
0.6140 |
|
Radiographic Erosion |
Positive |
648 (58.7) |
592 (57.87) |
56 (69.14) |
0.0600 |
|
ESR at 1st study visit |
mean (SD) |
37.58 (27.06) |
36.98 (26.60) |
45.15 (31.54) |
0.0102 |
|
CRP at 1st study visit |
mean (SD) |
20.23 (23.21) |
19.11 (22.24) |
33.56 (30.59) |
0.0248 |
|
No. of Tender Joints at 1st study visit |
mean (SD) |
1.84 (3.80) |
1.78 (3.69) |
2.54 (4.94) |
0.0817 |
|
No. of Swollen Joints at 1st study visit |
mean (SD) |
2.34 (3.59) |
2.26 (3.45) |
3.37 (4.90) |
0.0072 |
|
No. of deformity joints at 1st study visit |
mean (SD) |
2.30 (4.07) |
2.32 (4.14) |
2.09 (3.18) |
0.6166 |
|
DAS28 at 1st study visit |
mean (SD) |
3.35 (1.41) |
3.33 (1.39) |
3.61 (1.57) |
0.0894 |
|
Treatment history |
|||||
|
Duration of RA onset to 1st DMARD usage (mths) |
mean (SD) |
40.64 (65.34) |
39.43 (61.78) |
55.88 (99.04) |
0.0292 |
|
No. of DMARDs used at lst study visit |
Mean (SD) |
2.02 (1.29) |
2.03 (1.28) |
1.88 (1.32) |
0.3057 |
|
Methotrexate |
Ever |
802 (72.51) |
745 (72.68) |
57 (70.37) |
0.6980 |
|
Sulfasalazine |
Ever |
671 (60.67) |
620 (60.49) |
51 (62.96) |
0.7240 |
|
Hydroxychloroquine |
Ever |
459 (41.50) |
433 (42.24) |
26 (32.10) |
0.0800 |
|
Leflunomide |
Ever |
47 (4.25) |
44 (4.29) |
3 (3.70) |
1.0000 |
|
Gold |
Ever |
91 (8.23) |
84 (8.20) |
7 (8.64) |
0.8340 |
|
Penicillamine |
Ever |
106 (9.58) |
99 (9.66) |
7 (8.64) |
1.0000 |
|
Ciclosporin A |
Ever |
17 (1.54) |
15 (1.46) |
2 (2.47) |
0.3570 |
|
Biologics |
Ever |
6 (0.54) |
6 (0.59) |
0 (0) |
1.0000 |
To cite this abstract in AMA style:
Lim X, Liu L, Gao X, Tan JWL, Koh LW, Lian T, See WQ, Leong K, Koh E. Incidence and Risk Factors of Malignancy in a Cohort of Rheumatoid Arthritis Patients from Singapore [abstract]. Arthritis Rheumatol. 2015; 67 (suppl 10). https://acrabstracts.org/abstract/incidence-and-risk-factors-of-malignancy-in-a-cohort-of-rheumatoid-arthritis-patients-from-singapore/. Accessed .« Back to 2015 ACR/ARHP Annual Meeting
ACR Meeting Abstracts - https://acrabstracts.org/abstract/incidence-and-risk-factors-of-malignancy-in-a-cohort-of-rheumatoid-arthritis-patients-from-singapore/