Prognostic impact of six versus eight cycles of standard regimen in patients with diffuse large B-cell lymphoma: propensity score-matching analysis

Background

R-CHOP-21 has been the standard treatment for diffuse large B-cell lymphoma (DLBCL), but there is a paucity of evidence focusing on the number of cycles of regimens.

Patients and methods

We conducted a retrospective study to compare the effectiveness of six cycles of standard regimens versus eight cycles for overall survival (OS) in DLBCL patients using propensity score matching, in consideration of relative dose intensity (RDI).

Results

A total of 685 patients with newly diagnosed DLBCL were identified in three institutions from 2007 to 2017. Patients treated using six cycles of standard regimens were matched by propensity scores with those treated using eight cycles. A 1 : 1 propensity score matching yielded 138 patient pairs. Eight cycles did not significantly improve OS in the conventional Cox proportional hazards model (hazard ratio 0.849, 95% confidence interval 0.453-1.588, P = 0.608). Restricted cubic spline Cox models for OS confirmed that the effect of the number of cycles was not modified by total average RDI, the International Prognostic Index, and age. Occurrence of adverse events did not differ between six and eight cycles.

Conclusion

Even considering the impact of RDI, six cycles of the initial standard regimen for DLBCL is not inferior to eight cycles.

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The optimal number of cycles of standard regimens including R-CHOP-21 for newly diagnosed DLBCL has not been determined.

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This study was conducted to verify whether six cycles or eight cycles of standard regimen improved the prognosis of DLBCL.

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Propensity score matching and a Cox hazards model with restricted cubic spline were used in this study.

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No survival benefit of eight cycles compared with six cycles was seen, even taking into account RDI.

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Prognosis was no better with eight cycles of (R-)CHOP-21 or THP-COP-21 than with six cycles, after age and IPI modifications.

Denture quality has a minimal effect on health-related quality of life in patients with removable dentures

The present study examined the association of denture quality and health-related quality of life (HRQoL) in patients with removable dentures. In a study of 171 consecutive patients with removable partial dentures or complete dentures (mean age: 68·0 ± 9·3 years) at a university-based prosthodontic clinic, dentists rated two aspects of denture quality (stability and aesthetics) using a 100-mm visual analog scale (VAS). HRQoL was evaluated using the mental and physical component summary (MCS and PCS) scores of the Medical Outcomes Study Short-Form 36-Item Health Survey (SF-36). Oral health-related quality of life (OHRQoL) was evaluated using the Oral Health Impact Profile-Japanese version (OHIP-J). The associations among denture quality, OHRQoL, and HRQoL were examined by linear regression models. Bivariable linear regression analyses revealed that denture stability was significantly associated with the SF-36 MCS [regression coefficient = 0·52 for a 10-unit increase in denture stability on a 0-100 VAS, 95% confidence interval (CI): 0·03-1·00, P = 0·04], but not with the PCS (0·11, 95% CI: -0·49 to 0·70). Denture aesthetics was not related to the PCS or the MCS (0·22, 95% CI: -0·44 to 0·88 or 0·07, 95%CI: -0·47 to 0·62). When OHIP-J was added to the regression model, this variable was substantially and significantly associated with the MCS and PCS summary scores; in addition, the regression coefficient for denture quality decreased in magnitude and was statistically nonsignificant in all analyses. The quality of removable dentures had a minimal effect on HRQoL in patients with removable dentures, and this association was mediated by OHRQoL.