Abstract 836P
Background
The influence of socioeconomic status (SES) on access to standard chemotherapy and/or monoclonal antibody therapy, and associated secular trends, relative survival, and excess mortality, among diffuse large B-cell lymphoma (DLBCL) patients is not clear.
Methods
We developed a population-based study based on a territory-wide electronic database of Hong Kong. We identified adult patients with DLBCL who were histologically diagnosed between 2000 and 2018. We evaluated the odds and the secular trends of receipt of chemotherapy and/or rituximab by levels of SES. In addition, we estimated DLBCL long term relative survival by SES utilizing Hong Kong life tables.
Results
Among 4,017 patients with DLBCL, 2,363 (58·8%) patients received both chemotherapy and rituximab and 740 (18·4%) patients received chemotherapy alone, while 1,612 (40·1%) and 914 (22·8%) patients received no rituximab or chemotherapy, respectively. On multivariable analysis, low SES was associated with lesser use of any chemotherapy (OR, 0·44; 95% CI 0·34-0·57; p <0·001) and rituximab (OR, 0·41; 95% CI, 0·32-0·52; p < 0·001). The socioeconomic disparity for either treatment showed no secular trend of change. Additionally, patients with low SES showed increased excess mortality compared with those with high SES, with a hazard ratio of 2·34 (95% CI 1·67 to 3·28; P < 0·001). Table: 836P
Factors for initiation of any chemotherapy and rituximab by multivariable logistic regression models among patients with DLBCL, Hong Kong, 2000–2018 (N = 4,017)
| Characteristics | Use of Chemotherapy vs None | Use of Rituximab vs None | ||
| OR (95% CI) | P | OR (95% CI) | P | |
| SES (Lower vs Higher) | 0.44 (0.34 to 0.57) | <0.001 | 0.41 (0.32 to 0.52) | <0.001 |
| Age (>60 vs ≤60) | 0.41 (0.34 to 0.51) | <0.001 | 0.72 (0.61 to 0.85) | <0.001 |
| Sex (Male vs Female) | 0.99 (0.83 to 1.18) | 0.916 | 0.80 (0.68 to 0.93) | 0.004 |
| RCS Comorbidity score (One vs Zero) | 1.11 (0.90 to 1.37) | 0.345 | 1.10 (0.92 to 1.32) | 0.297 |
| (Two vs Zero) | 0.80 (0.64 to 0.99) | 0.044 | 0.84 (0.69 to 1.02) | 0.087 |
| Year of diagnosis (2005–2009 vs 2000–2004) | 2.39 (1.84 to 3.10) | <0.001 | 5.92 (4.58 to 7.66) | <0.001 |
| (2010–2014 vs 2000–2004) | 2.98 (2.30 to 3.87) | <0.001 | 12.92 (9.93 to 16.79) | <0.001 |
| (2015–2018 vs 2000–2004) | 2.26 (1.74 to 2.93) | <0.001 | 12.03 (9.20 to 15.73) | <0.001 |
Abbreviations: CI, confidence intervals; OR, odds ratio; RCS, Royal College of Surgeons; SES, socioeconomic status
Conclusions
In this Asian population-based study on patients with DLBCL, low SES was associated with a lower propensity of receipt of chemotherapy and/or rituximab. Furthermore, low SES was associated with an increased excess mortality and markedly reduced relative survival compare to those with higher SES.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
The authors.
Funding
Spanish National Health Institute.
Disclosure
All authors have declared no conflicts of interest.