This study systematically analyzed the TP53 mutation status in 253 DLBCL patients, exploring its mutational characteristics and prognostic value. While TP53 mutations are generally associated with poor treatment response and adverse prognosis in most cancers, there is significant heterogeneity in clinical outcomes among different TP53 mutants [17]. Functional assessment of TP53 genetic alterations is crucial for optimizing risk stratification, identifying prognostically distinct subgroups, and guiding individualized therapy for DLBCL patients.
Our study revealed significant site-specific prognostic heterogeneity among TP53 hotspot mutations. The high-risk group (G245, R175, R248, R273, R282) was associated with significantly shorter PFS and OS, whereas the low-risk group (C242, Y234, Y236) showed outcomes statistically similar to TP53-wt patients. This finding aligns with the concept of functional heterogeneity among TP53 mutants. For instance, Blandino et al. showed that specific mutants (e.g., His175, His179) can confer a selective survival advantage during chemotherapy[26]. Young et al. reported that in DLBCL, hotspot codons 158, 175, 245, 248, 273, 280, and 282 were associated with the highest mortality rates [23].
This site-specific prognostic difference may stem from distinct downstream oncogenic pathways activated by different mutants. For example, the R175H mutant has been shown to specifically bind the BACH1/LSD2 complex, promoting tumor metastasis by suppressing ferroptosis via histone demethylation [27]. G245S and R175H can cooperatively lift the transcriptional repression of IL-34, fostering an immunosuppressive microenvironment via a CSC–IL-34–macrophage axis [28]. The R273H mutant can reshape tumor cell glycosylation and metabolism by relieving negative regulation of MGAT4A [29]. These findings suggest that precision targeting of mutant-specific pathways is a promising future direction for treating TP53-mutated DLBCL.
Our findings support a refined risk stratification based on the TP53 mutational profile. Patients in the high-risk group who received R-CHOP plus targeted therapy had survival outcomes comparable to TP53-wt patients, suggesting this combination may mitigate the adverse prognosis. We propose that patients with high-risk mutations should be considered for R-CHOP-based combination therapies and enrollment in trials exploring novel agents targeting pathways like BACH1/LSD2, IL-34, or MGAT4A. In contrast, standard R-CHOP may remain a viable option for patients with low-risk mutations.
Consistent with previous research [30], we found that mutations in key DBD motifs (Loop-L2, Loop-L3, and LSH) were associated with poor prognosis. However, unlike some studies [24], we did not find that mutation type (missense vs. non-missense) or VAF (using a 50% cutoff) could stratify prognosis. This discrepancy with a study by Zhang et al., which found a VAF > 34% to be a poor prognostic marker [31], suggests that the prognostic value of VAF may depend on an optimized cutoff, which requires further investigation in larger cohorts.
The treatment of TP53-mutated DLBCL remains a major clinical challenge. Our results show that neither standard R-CHOP nor intensified R-DAEPOCH regimens significantly improved outcomes for these patients, consistent with other studies [15, 32]. Importantly, in the R-CHOP + X cohort, the survival outcomes of TP53-mut patients were not significantly different from TP53-wt patients, reinforcing the potential of combination strategies.
Bruton's Tyrosine Kinase (BTK) inhibitors like zanubrutinib, which block the essential B-cell receptor (BCR) signaling pathway, are a rational choice, as about 45% of A53-subtype DLBCLs have alterations in the BCR-dependent NF-κB pathway [7, 33]. Our finding of no prognostic difference between TP53-mut and TP53-wt patients in the ZR-CHOP group supports this approach. This aligns with findings in other hematologic malignancies like CLL, where targeted therapies are prioritized for patients with TP53 alterations [34]
While CAR-T cell therapy and ASCT are important salvage options for R/R DLBCL [35, 36], our study suggests that TP53 mutations may limit their efficacy, as evidenced by the significantly lower 2-year PFS rate in TP53-mut patients. This highlights the need for novel strategies, such as CAR-T followed by consolidative ASCT, which has shown promise in improving outcomes for this high-risk population.
In the context of molecular subtypes, our study confirmed that TP53 mutations confer a poor prognosis in DEL, consistent with Meriranta et al[37]. The lack of a significant finding in DHL was likely due to the small sample size. Since there was no prognostic difference between DEL/DHL and non-DEL/non-DHL status within the TP53-mut cohort, TP53 mutation may act as an independent, high-risk prognostic factor.
At the protein expression level, p53 immunohistochemistry (IHC) serves as a surrogate marker for inferring TP53 mutation status, and previous studies have explored various positivity thresholds. Some studies have proposed that p53 expression > 50% or a pattern of either ≥ 65% (overexpression) or < 1% (complete absence) are effective cutoffs [30, 38]. Our study found that in diffuse large B-cell lymphoma (DLBCL), the majority of cases with *TP53* mutations exhibited high levels of p53 protein expression (> 75%). This suggests that the optimal threshold may vary by tumor type and assay conditions, highlighting the need for future standardization in large, multicenter cohorts.
In summary, TP53 mutation is a key adverse prognostic factor in DLBCL. Given the marked prognostic heterogeneity associated with different TP53 hotspot mutations, clinical practice should incorporate refined risk stratification based on the TP53 mutational profile. For patients harboring high-risk mutations (e.g., G245, R175, R248, R273, and R282), the exploration of novel combination therapies targeting relevant pathways is recommended. Conversely, for those with low-risk mutations (e.g., C242, Y234, and Y236), the standard R-CHOP regimen remains a viable treatment option. In the future, more prospective clinical trials are needed to validate the efficacy of R-CHOP combined with targeted agents in TP53-mutated DLBCL. Such studies will be crucial for optimizing current therapeutic strategies to improve patient outcomes and quality of life.