Tumor Size Linked to Risk for Relapse

TOPLINE:

Maximum tumor diameter (MTD) showed a strong association with the risk for relapse in patients with limited-stage Hodgkin lymphoma (HL) achieving PET negativity, with each centimeter increase in MTD linked to a 21% higher risk for relapse.

METHODOLOGY:

• Researchers analyzed 1278 patients with stage I/IIA HL without mediastinal bulk who achieved PET negativity after doxorubicin, bleomycin, vinblastine, and dacarbazine treatment across two trials: RAPID (n = 419) and H10 (n = 859).
• Participants received either chemotherapy alone (n = 514) or combined modality therapy with chemotherapy plus radiotherapy (n = 764), with treatment allocation determined by trial protocols.
• Analysis included evaluation of baseline MTD measured using CT, with investigators examining its association with event-free survival and progression-free survival.

TAKEAWAY:

• MTD demonstrated a consistent association with event-free survival in both the H10 validation cohort (hazard ratio [HR], 1.22; 95% CI, 1.07-1.38; P = .003) and the RAPID cohort (HR, 1.19; 95% CI, 1.02-1.39; P = .02).
• Treatment modality and MTD emerged as independent risk factors, with patients receiving chemotherapy alone showing a 5-year event-free survival rate of 92.4% (95% CI, 89.1%-94.7%) with MTD < 5 cm vs 82.3% (95% CI, 73.8%-88.2%) with MTD ≥ 5 cm.
• According to the researchers, no clear MTD threshold was identified above which marked differences in event-free survival occurred, suggesting a continuous relationship between the tumor size and the risk for relapse.

IN PRACTICE:

“This international validation study confirms MTD is strongly associated with relapse risk in patients with LS-HL [limited-stage HL] achieving PET− and informs decision-making around risk-adapted application of radiotherapy…Treatment modality and MTD were independent risk factors; patients with higher MTD receiving chemotherapy alone had the greatest relapse risk,” the authors of the study wrote.

SOURCE:

This study was led by Elizabeth H. Phillips, PhD, Division of Cancer Sciences, The University of Manchester and Manchester Academic Health Science Centre, Manchester, England. It was published online on May 13 in Blood Advances.

LIMITATIONS:

According to the authors, this study lacked centralized radiology review, which may have affected the consistency of MTD measurements across different imaging planes. Additionally, baseline PET assessment was not mandatory in either trial, limiting the ability to compare tumor diameter measurements with advanced PET metrics such as metabolic tumor volume.

DISCLOSURES:

This study received support from the National Institute for Health Research and Social Care, the Wellcome/EPSRC Centre for Medical Engineering at King’s College London, and the National Institute for Health Research Manchester Biomedical Research Centre. Additional disclosures are noted in the original article.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.