Long term follow-up of combination chemotherapy-radiotherapy of stage III Hodgkin's disease: a Cancer and Acute Leukemia Group B study

Second malignancy risk associated with treatment of Hodgkin's lymphoma: meta-analysis of the randomised trials

BACKGROUND

Despite several investigations, second malignancy risks (SMR) following radiotherapy alone (RT), chemotherapy alone (CT) and combined chemoradiotherapy (CRT) for Hodgkin's lymphoma (HL) remain controversial.

PATIENTS AND METHODS

We sought individual patient data from randomised trials comparing RT versus CRT, CT versus CRT, RT versus CT or involved-field (IF) versus extended-field (EF) RT for untreated HL. Overall SMR (including effects of salvage treatment) were compared using Peto's method.

RESULTS

Data for between 53% and 69% of patients were obtained for the four comparisons. (i) RT versus CRT (15 trials, 3343 patients): SMR were lower with CRT than with RT as initial treatment (odds ratio (OR) = 0.78, 95% confidence interval (CI) = 0.62-0.98 and P = 0.03). (ii) CT versus CRT (16 trials, 2861 patients): SMR were marginally higher with CRT than with CT as initial treatment (OR = 1.38, CI 1.00-1.89 and P = 0.05). (iii) IF-RT versus EF-RT (19 trials, 3221 patients): no significant difference in SMR (P = 0.28) although more breast cancers occurred with EF-RT (P = 0.04 and OR = 3.25).

CONCLUSIONS

Administration of CT in addition to RT as initial therapy for HL decreases overall SMR by reducing relapse and need for salvage therapy. Administration of RT additional to CT marginally increases overall SMR in advanced stages. Breast cancer risk (but not SMR in general) was substantially higher after EF-RT. Caution is needed in applying these findings to current therapies.

The cancer and leukemia group B lymphoma committee

The malignant lymphomas include at least 30 entities that are distinct with respect to histology, immunology, genetics, clinical features, and outcome following therapy. The clinical behavior of these diseases ranges from indolent but generally incurable to aggressive and frequently fatal yet potentially curable with appropriate chemotherapy or chemotherapy-antibody regimens. Over the past 50 years, the Cancer and Leukemia Group B (CALGB) Lymphoma Committee has conducted a series of clinical trials that have contributed to an improvement in outcome for patients with a number of the more common lymphoma subtypes. The World Health Organization has classified approximately 30 neoplastic diseases of the hematopoietic and lymphoid tissues (1). The Cancer and Leukemia Group B (CALGB) Lymphoma Committee highlight below clinical trials that have resulted in improved patient outcome for the more frequent lymphoma subtypes.

Radiation oncology research in the cancer and leukemia group B

Radiation oncology initiatives have been an integral component in the evolution of multidisciplinary research in the Cancer and Leukemia Group B. Although early studies in the Group primarily focused on chemotherapy for hematologic and pediatric malignancies, the Radiation Oncology Committee was established in 1972, reflecting the broadening scope of clinical investigation with an increased emphasis on solid tumor research. A major early contribution of the Radiation Oncology Committee was the recognition of the importance of formalized radiation quality review, which led to the development of the Quality Assurance Review Center. The committee has been instrumental in designing trials, in conjunction with our medical oncology and surgical oncology colleagues, to assess multimodality therapy. The results of many of these studies have had important implications for clinical practice. Recent efforts have explored our major research theme of treatment intensification via radiotherapy dose modulation and novel combinations of radiotherapy with sensitizing agents, with an emphasis on safely implementing advanced technologies in the cooperative group setting.

Chemotherapy, radiotherapy and combined modality for Hodgkin's disease, with emphasis on second cancer risk

BACKGROUND

Second malignancies (SM) are a major late effect of treatment for Hodgkin's disease (HD). Reliable comparisons of SM risk between alternative treatment strategies are lacking.

OBJECTIVES

Radiotherapy (RT), chemotherapy (CT) and combined chemo-radiotherapy (CRT) for newly-diagnosed Hodgkin's disease are compared with respect to SM risk, overall (OS) and progression-free (PFS) survival. Further, involved-field (IF-)RT is compared to extended-field (EF-)RT.

SEARCH STRATEGY

We searched the Cochrane Controlled Trials Register, PubMed, EMBASE, CancerLit, LILACS, relevant conference proceedings, trials lists and publications.

SELECTION CRITERIA

RCTs accruing 30+ patients and completing accrual before/during 2000, comparing at least two treatment modalities for newly-diagnosed HD.

DATA COLLECTION AND ANALYSIS

Individual patient data were collected and assessed for data quality. Trialists submitted additional information concerning methods and data quality. Peto Odds Ratios (OR) with 95% confidence intervals (CI) were calculated for OS, PFS and SM-free survival. Secondary acute leukemia (AL), non-Hodgkin's lymphoma (NHL) and solid tumours (ST) were also analysed separately.

MAIN RESULTS

37 trials (9312 patients) were analysed: 15 (3343) for RT vs. CRT, 16 (2861) for CT vs. CRT, 3 (415) for RT vs. CT and 10 (3221) for IF-RT vs. EF-RT.CRT was superior to RT in terms of OS (OR=0.76, CI=0.66 to 0.89, p=0.0004), PFS (OR=0.49, CI=0.43 to 0.56, p<0.0001) and SM (OR=0.78. CI=0.62 to 0.98, p=0.03). The superiority of CRT also applied to early and advanced stages (mainly IIIA) separately. Excess SM with RT is due mainly to ST and is apparently caused by greater need for salvage therapy after RT.CRT was superior to CT in terms of PFS (OR=77, CI 0.68 to 0.77, p<0.0001). OS was better with CRT for early stages only (OR=0.62, CI 0.44 to 0.88, p=0.006). SM risk was higher with CRT (OR=1.38, CI 1.00 to 1.89, p=0.05), although not significant for early stages alone. This effect, also seen in AL and ST separately, was due directly to first-line treatment. Data were insufficient to compare RT to CT.EF-RT was superior to IF-RT (each additional to CT in most trials) in terms of PFS (OR=81, CI 0.68 to 0.95, p=0.009) but not OS. No significant difference in SM was observed.

AUTHORS' CONCLUSIONS

CRT seems to be optimal for most early stage (I-II) HD patients. For advanced stages (III-IV), CRT better prevents progression/relapse but CT alone seems to cause less SM. RT alone gives a higher overall SM risk than CRT due to increased need for salvage therapy. Reduced SM risk after IF-RT instead of EF-RT could not be demonstrated. Due to the large number of studies excluded because no IPD were received, to the inclusion of many outdated treatments and to the limited amount of long-term data, one must be cautious in applying these results to current therapies.

Prognostic factors in Hodgkin's disease stage III with special reference to tumour burden

143 patients with Hodgkin's disease stage III (65 PS III, 78 CS III) were treated with radiotherapy alone (33 patients), combination chemotherapy alone (56 patients), or radiotherapy plus combination chemotherapy (54 patients). They were followed till death or from 7 to 191 months. Prognostic factors including treatment, peripheral + intrathoracic tumour burden (assessed by combining tumour size in each involved region with number of involved regions), intraabdominal tumour burden (assessed by combining size of lymphographically involved lymph nodes in each region with number of lymphographically involved regions), histologic subtype, B-symptoms, number of involved regions, mediastinal involvement, pretreatment ESR, sex, age, laparotomy, and substage were examined in multivariate analysis. With regard to disease-free survival, total tumour burden (intraabdominal and peripheral + intrathoracic) emerged as the only pre-treatment factor of independent prognostic significance. With regard to overall survival the only factor of independent significance apart from age turned out to be intraabdominal tumour burden. The results of the present study thus support recently published findings regarding early stage disease to the effect that tumour burden is the single most important prognostic factor in Hodgkin's disease.

Second malignancies and Hodgkin's disease--the Royal Marsden Hospital experience

The frequency of secondary malignant neoplasms occurring in patients treated for Hodgkin's disease at the Royal Marsden Hospital between 1963 and 1978 is reported and the literature is reviewed. 730 patients were reviewed and 583 patients permanently resident in the United Kingdom were included in the analysis. The frequency of leukaemia and solid tumors was determined from age- and sex-corrected data from the South Thames Cancer Registry. Thirty-seven malignancies were recorded in 36 patients including 9 leukaemias, 10 lung cancers, 6 skin cancers and 2 non-Hodgkin's lymphoma, all of which were observed in significant excess. When all remaining sites are combined, there was a slight excess but no one site is individually significant.

A Southwest Oncology Group: chemotherapy versus chemotherapy plus radiotherapy in treatment of stage III Hodgkin's disease

The Southwest Oncology Group (SWOG) performed a randomized study (SWOG 7518, CAR 2) of chemotherapy using ten courses of nitrogen mustard, vincristine, procarbazine, and prednisone (MOPP) plus low-dose bleomycin (LDB), versus three courses of combined therapy, MOPP + LDB plus radiotherapy (XRT) from October, 1974, to April 1980, in pathologic stage III Hodgkin's disease. The present report includes data on 136 registered patients, of whom 112 are fully or partially evaluable. At this preliminary analysis, complete remission rates are 82% for chemotherapy alone and 82% for combined treatment. There are no statistically significant differences in survival or relapse-free survival between the two treatment programs, and no specific trends for stage IIIA versus IIIB. The estimated 3-year survival rate for all patients was 82%. Toxicities are comparable when considering the highest grades. There was one case of acute myeloblastic leukemia on combined treatment. Preliminary evidence suggests that patients with nodular sclerosis histologic type are more likely to relapse on chemotherapy alone than on combined treatment.

Reassessment of prognostic factors in stage IIIA and IIIB Hodgkin's disease treated with MOPP and radiotherapy

Prognostic factors have been re-evaluated for 88 patients with Stage III Hodgkin's disease to see if they have remained significant on a long-term basis. Treatment had consisted of two cycles of MOPP followed by radiotherapy to the mantle, abdomen, and pelvis; all patients had achieved complete remission. Case material was grouped according to the presence of absence of mediastinal disease. Five-year survivals for Stage IIIA and IIIB patients were 85 and 80%; corresponding disease-free survivals were 76 and 73%. Significant prognostic factors include age, histopathology, and extent of abdominal disease, but the relative importance of these factors differs for the mediastinal and nonmediastinal patients. Modifications of current treatment policy for both mediastinal and nonmediastinal patients are discussed in relation to the prognostic factors.