Large mediastinal tumor mass as a prognostic factor in Hodgkin’s lymphoma

Two distinct prognostic groups in advanced-stage Hodgkin lymphoma revealed by the presence and site of bulky disease

Controversy exists regarding the definition and prognostic significance of bulk in advanced-stage (stage III/IV) Hodgkin lymphoma (ASHL), and bulk location (mediastinum vs other sites) further complicated the setting. This retrospective, multi-institutional study comprised 814 ASHL patients between 2000 and 2010 and aimed to evaluate the significance of bulk in ASHL. End points of interest included progression-free survival (PFS) and overall survival (OS). Covariates included maximum diameter and the site of bulky disease. SmoothHR and Kaplan-Meier analyses were used to assess for an association of PFS and OS with covariates. In the exploratory cohort (n = 683), maximum diameter had no association with PFS and a complex, U-shaped association with all-cause mortality on smoothHR analysis. Using 5 cm as a cutoff for bulk, Kaplan-Meier analyses confirmed the smoothHR results. The site of bulk was incorporated to divide patients into 2 groups. The mediastinal bulk (MB) type had more favorable characteristics than the nonbulky/non-MB (NB/NMB) type on age, histology, and bone marrow involvement (P < .001). The MB type was associated with better OS than the NB/NMB-type on univariable analysis (5-year OS, 92% vs 86%; HR, 0.53; 95% confidence interval, 0.34-0.84; P = .007). These findings persisted in the subgroup treated with chemotherapy alone and were confirmed in an independent validation cohort (n = 131). Our findings indicate that mediastinal bulk was associated with more favorable disease characteristics and improved OS in ASHL, and may be a surrogate of a more favorable biology.

Volumetric assessment of mediastinal lymphoma masses in Hodgkin lymphoma

The large mediastinal mass (LMM) at initial staging represents a risk factor in Hodgkin lymphoma (HL) and is measured by X-ray. Depending on location of the LMM, different results can occur regardless of the initial lymphoma volume. To assess this risk factor more accurately, we evaluated the method of volumetry in 77 patients of HD13/14 study of the German Hodgkin Study Group. Furthermore, volume calculations based on three or only one diameter, were performed to simplify volume assessment. Inter-rater reliability was good for all methods. The 3-diameter measurement produced larger volumes than volumetric assessment with an intraclass correlation coefficient (ICC) of 0.93, which could be improved to 0.95 by multiplying volumes with a correction factor of 0.86. The 1-dimensional measurement strongly overestimated the volume with an ICC of 0.7. In conclusion, the simplified volume estimation based on 3 largest diameters provides a reliable concept for the staging of HL patients.

Anterior mediastinal solid tumours in adults: characterisation using dynamic contrast-enhanced MRI, diffusion-weighted MRI, and FDG-PET/CT

AIM

To find significant parameters to characterise anterior mediastinal solid tumours in adults using dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI), diffusion-weighted MRI (DWI), and combined 2-[(18)F]-fluoro-2-deoxy-d-glucose positron-emission tomography/computed tomography (FDG-PET/CT).

MATERIALS AND METHODS

Forty-eight histologically confirmed anterior mediastinal solid tumours in 48 patients (24 men, 24 women; age range 21-83 years, mean 50.7 years) were examined. The parameters analysed were maximal diameter, presence of capsule/septa on T2-weighted images, time-signal intensity curves (TICs), apparent diffusion coefficient (ADC), and maximum standardised uptake value (SUVmax). Also examined was whether any differences between histological types could be seen in these parameters. In a validation study, 42 anterior mediastinal solid tumours in 42 patients were examined consecutively.

RESULTS

The washout pattern on TIC was seen only in thymic epithelial tumours (20/32). SUVmax of lymphoma (mean, 17.9), malignant germ cell tumours (14.2), and thymic carcinomas (15.6) were significantly higher than that of thymomas (6.1). The mean maximal diameter of thymic epithelial tumours was significantly smaller than that of lymphomas (p<0.01) and malignant germ cell tumours (p<0.05). The validation study also yielded high accuracy (38/42, 91%) in differentiation among the anterior mediastinal solid tumours.

CONCLUSION

The SUVmax, TIC pattern on DCE-MRI, and maximal diameter might be useful to differentiate anterior mediastinal solid tumours in adults.

Randomized Phase III Trial Comparing ABVD Plus Radiotherapy With the Stanford V Regimen in Patients With Stages I or II Locally Extensive, Bulky Mediastinal Hodgkin Lymphoma: A Subset Analysis of the North American Intergroup E2496 Trial

PURPOSE

The phase III North American Intergroup E2496 Trial (Combination Chemotherapy With or Without Radiation Therapy in Treating Patients With Hodgkin's Lymphoma) compared doxorubicin, bleomycin, vinblastine, and dacarbazine (ABVD) with mechlorethamine, doxorubicin, vincristine, bleomycin, vinblastine, etoposide, and prednisone (Stanford V). We report results of a planned subgroup analysis in patients with stage I or II bulky mediastinal Hodgkin lymphoma (HL).

PATIENTS AND METHODS

Patients were randomly assigned to six to eight cycles of ABVD every 28 days or Stanford V once per week for 12 weeks. Two to 3 weeks after completion of chemotherapy, all patients received 36 Gy of modified involved field radiotherapy (IFRT) to the mediastinum, hila, and supraclavicular regions. Patients on the Stanford V arm received IFRT to additional sites ≥ 5 cm at diagnosis. Primary end points were failure-free survival (FFS) and overall survival (OS).

RESULTS

Of 794 eligible patients, 264 had stage I or II bulky disease, 135 received ABVD, and 129 received Stanford V. Patient characteristics were matched. The overall response rate was 83% with ABVD and 88% with Stanford V. At a median follow-up of 6.5 years, the study excluded a difference of more than 21% in 5-year FFS and more than 16% in 5-year OS between ABVD and Stanford V (5-year FFS: 85% v 79%; HR, 0.68; 95% CI, 0.37 to 1.25; P = .22; 5-year OS: 96% v 92%; HR, 0.49; 95% CI, 0.16 to 1.47; P = .19). In-field relapses occurred in < 10% of the patients in each arm.

CONCLUSION

For patients with stage I or II bulky mediastinal HL, no substantial statistically significant differences were detected between the two regimens, although power was limited. To the best of our knowledge, this is the first prospective trial reporting outcomes specific to this subgroup, and it sets a benchmark for comparison of ongoing and future studies.