Significance of bulky mass and residual tumor—Treated with or without consolidative radiotherapy—To the risk of relapse in DLBCL patients

Abstract

Bulky and residual tumor are considered to increase the risk of relapse in diffuse large B‐cell lymphoma (DLBCL) patients. Radiotherapy is conventionally used to reduce the risk, but the evidence is controversial. We performed a retrospective analysis to evaluate the significance of bulky and residual tumor treated with or without radiotherapy in DLBCL patients. We analyzed 312 DLBCL patients treated from 2010‐2017 in Oulu University Hospital. A bulky tumor was detected in 123 patients and 55 of these patients (44.3%) received consolidative radiation therapy (RT) to the bulky tumor. Residual tumor meeting the required criteria was found in 138 (39.3%) patients, and 65 (45.5%) of these patients received consolidative RT to the site of residual tumor. iPET‐CT scans were performed in 102 patients. In multivariate analyses, bulky was an independent risk factor in limited stage patients in progression free survival (HR 6.43 [95%CI 1.609‐25.710]; P = .008) not related to International prognostic index (HR 1.35 [95% CI 0.256‐7.124]; P = .724) or age (HR 1.62 [95% CI 0.468‐5.638]; P = .445). This was not seen in advanced stage patients or in patients with residual tumor. Radiotherapy to the bulky or residual tumor was not able to improve the long‐term PFS of patients. In this study, it appears that performing iPET is the most convincing method in improving evaluation and in finding patients with increased risk of relapse. Evidently, patients with negative iPET will not benefit from including RT in the treatment after metabolic complete response (CR), and patients with primary refractory disease are most likely in the group of positive iPET.

A Favorable Outcome of Grade 3 Follicular Lymphoma Treated With Surgery and Obinutuzumab Combined With Chemotherapy: A Case Report and Literature Review

“…In continuing the challenge in treating our patient’s condition, studies reviewing the significance of extranodal maximum tumor diameter (EN-MTD) in the treatment of DLBCL have demonstrated that patients have a higher progression-free survival rate if their EN-MDT was <7.5 cm [ 17 - 19 ]. Our patient had promising prognostic factors because of his EN-MDT < 7.5 cm, but his less favorable clinical presentation of malignancy-related SBO eventually led the clinical team to treat him as if he had “bulky” DLBCL (defined as mass ≥ 7.5 cm) [ 14 , 17 , 18 ]. Ultimately, our patient received six cycles of R-CHOP (transitioned to O-CHOP due to tolerability), with a complete successful response to chemotherapy [ 14 , 18 ].…”

Evolution of therapy for limited stage diffuse large B-cell lymphoma

“…Among limited-stage patients, the presence of bulky tumor was associated with inferior prognosis, with 2-year PFS of 53% compared to 90% to those with non-bulky disease; however, the benefit of RT in delaying time to progression disappeared after excluding primary refractory cases. They additionally noted that within bulky disease, a negative iPET retained its favorable prognostic benefit, with a 2-year PFS of 87% for those with negative iPET and bulky disease, compared to 57% for those with a positive iPET [ 53 ]. While retrospective in nature, this study suggests that RT provides an additional benefit in cases of bulky limited-stage disease such as primary refractory disease, but reinforces that a negative iPET retains its prognostic power even in the presence of other risk factors and that RT may not be necessary.…”

The Effect of the Tumor Microenvironment on Lymphoid Neoplasms Derived from B Cells

“…The higher percentage of tryptase + mast cells found in the non-responders' group when compared with the responders' group positively correlated with the MVD [24], indicating the important role of mast cells in promoting and sustaining tumor angiogenesis in DLBCL. Bulky and residual tumors are considered to increase the risk of relapse in DLBCL patients [26]. To investigate the complex relationships occurring between immune cells, stromal cells, endothelial cells and the tumor cells, the involvement of T cells in the control of bulky and non-bulky DLBCL development and their correlation with mast cells and MVD has been estimated [27].…”