Second malignant neoplasms among long-term survivors of Hodgkin's disease: a population-based evaluation over 25 years

Chemotherapy only for localized Hodgkin lymphoma

Radiation therapy (RT) alone and more recently in combination with chemotherapy (combined modality therapy; CMT) has been the cornerstone of curative treatment for early-stage Hodgkin lymphoma (HL) for over 40 years. Because of increasing awareness of the late morbidity and mortality associated with RT, recent treatment regimens have attempted to limit its use. Chemotherapy only has been demonstrated to be a treatment option for most patients with localized HL. Current clinical trials have targeted subgroups of such patients who may be at an increased risk of recurrence for the addition of limited RT to chemotherapy.

Rationale for and preliminary results of proton beam therapy for mediastinal lymphoma

PURPOSE

To evaluate the potential of three-dimensional proton beam therapy (3D-PBT) for reducing doses to normal structures in patients with mediastinal lymphomas compared with conventional photon radiation therapy (RT).

METHODS AND MATERIALS

We treated 10 consecutive patients with mediastinal masses from lymphomas with 3D-PBT between July 2007 and February 2009 to 30.6-50.4 cobalt-Gray equivalents (CGE). Of those patients, 7 had primary refractory or recurrent disease, and 8 had Hodgkin lymphoma. Dosimetric endpoints were compared with those from conventional RT plans.

RESULTS

PBT delivered lower mean doses to the lung (6.2 vs. 9.5 Gy), esophagus (9.5 vs. 22.3 Gy), and heart (8.8 vs. 17.7 Gy) but not the breasts (5.9 vs. 6.1 Gy) than did conventional RT. Percentages of lung, esophagus, heart, and coronary artery (particularly the left anterior descending artery) volumes receiving radiation were consistently lower in the 3D-PBT plans over a wide range of radiation doses. Of the 7 patients who had residual disease on positron emission tomography before PBT, 6 (86%) showed a complete metabolic response.

CONCLUSIONS

In patients with mediastinal lymphomas, 3D-PBT produced significantly lower doses to the lung, esophagus, heart, and coronary arteries than did the current conventional RT. These lower doses would be expected to reduce the risk of late toxicities in these major organs.

Site-specific dose-response relationships for cancer induction from the combined Japanese A-bomb and Hodgkin cohorts for doses relevant to radiotherapy

Background and Purpose

Most information on the dose-response of radiation-induced cancer is derived from data on the A-bomb survivors. Since, for radiation protection purposes, the dose span of main interest is between zero and one Gy, the analysis of the A-bomb survivors is usually focused on this range. However, estimates of cancer risk for doses larger than one Gy are becoming more important for radiotherapy patients. Therefore in this work, emphasis is placed on doses relevant for radiotherapy with respect to radiation induced solid cancer.

Materials and methods

For various organs and tissues the analysis of cancer induction was extended by an attempted combination of the linear-no-threshold model from the A-bomb survivors in the low dose range and the cancer risk data of patients receiving radiotherapy for Hodgkin's disease in the high dose range. The data were fitted using organ equivalent dose (OED) calculated for a group of different dose-response models including a linear model, a model including fractionation, a bell-shaped model and a plateau-dose-response relationship.

Results

The quality of the applied fits shows that the linear model fits best colon, cervix and skin. All other organs are best fitted by the model including fractionation indicating that the repopulation/repair ability of tissue is neither 0 nor 100% but somewhere in between. Bone and soft tissue sarcoma were fitted well by all the models. In the low dose range beyond 1 Gy sarcoma risk is negligible. For increasing dose, sarcoma risk increases rapidly and reaches a plateau at around 30 Gy.

Conclusions

In this work OED for various organs was calculated for a linear, a bell-shaped, a plateau and a mixture between a bell-shaped and plateau dose-response relationship for typical treatment plans of Hodgkin's disease patients. The model parameters (α and R) were obtained by a fit of the dose-response relationships to these OED data and to the A-bomb survivors. For any three-dimensional inhomogenous dose distribution, cancer risk can be compared by computing OED using the coefficients obtained in this work.

Risk of second cancer after initial treatment of breast cancer: An Osaka Cancer Registry Database study

In the present study, the association between the incidence of second cancer and initial treatment for primary breast cancer was investigated using the Osaka Cancer Registry in Japan. We selected 45,575 patients diagnosed with breast cancer between January 1975 and December 2003. Information on initial cancer treatment and second cancer was obtained from the Osaka Cancer Registry. Patients were classified according to initial treatment (chemo-, hormone, or radiotherapy, or no treatment). We calculated the incidence rate ratio of second cancers in patients classified by treatment for the first cancer. The effects of treatment adjusted for covariates on second cancers were examined using stratified analyses and a Cox proportional hazard model. The final number of 33,043 subjects had a mean duration of follow-up of 5.2±4.3 years, during which 1,857 second cancers were diagnosed. For hormone therapy, the incidence rate ratio (IRR) of all second cancers was 0.64 [95% confidence interval (CI), 0.58-0.70], and that of corpus uteri cancer was 3.04 (95% CI, 1.78-5.19). The multivariate analysis revealed that the IRR of corpus uteri cancer associated with hormone therapy was 2.53 (95% CI, 1.41‑4.55). The incidence rate of all second cancers associated with initial treatment was lower than that associated with no treatment. Only second corpus uteri cancer may be related to hormone therapy.

The cancer is over, now what?: Understanding risk, changing outcomes

About 26,000 adolescents and young adults ages 15 to 29 years are diagnosed with invasive cancer each year. Although >80% will survive beyond 5 years from their cancer diagnosis, many will develop serious morbidity or die prematurely secondary to health problems in part related to their cancer therapy. This article provides a brief overview of mortality, morbidity, and health status among long-term survivors of adolescent and young adult (AYA) cancer. Four examples were used to illustrate the potential of risk-reducing strategies: breast cancer after chest irradiation, coronary artery disease after chest irradiation, cardiovascular disease in testicular cancer survivors, and the multitude of health problems faced by survivors receiving an allogeneic hematopoietic stem cell transplant. A conceptual model for risk-based health care was presented and future directions of the delivery of care for AYA cancer survivors discussed.

Survival after second primary lung cancer: a population-based study of 187 Hodgkin lymphoma patients

BACKGROUND

Lung cancer accounts for the largest absolute risk of second malignancies among Hodgkin lymphoma (HL) survivors. However, no population-based studies have compared overall survival (OS) between HL survivors who developed nonsmall cell lung cancer (HL-NSCLC) versus patients with first primary NSCLC (NSCLC-1).

METHODS

The authors compared the OS of 178,431 patients who had NSCLC-1 and 187 patients who had HL-NSCLC (among 22,648 HL survivors), accounting for sex, race, sociodemographic status, calendar year, and age at NSCLC diagnosis, and NSCLC histology and stage. All patients were reported to the population-based Surveillance, Epidemiology, and End Results Program. Hazard ratios (HRs) were derived from a Cox proportional hazards model.

RESULTS

Although the NSCLC stage distribution was similar in both groups (20% localized, 30% regional, and 50% distant), HL survivors experienced significantly inferior stage-specific OS. For patients with localized, regional, and distant stage NSCLC, the HRs (95% confidence interval [CI]) for death among HL survivors were 1.60 (95% CI, 1.08-2.37; P < .0001), 1.67 (95% CI, 1.26-2.22; P = .0004), and 1.31 (95% CI, 1.06-1.61; P = .013), respectively. Among HL-NSCLC patients, significant associations were observed between more advanced NSCLC stage and the following variables: younger age at HL diagnosis (P = .003), younger age at NSCLC diagnosis (P = .048), and longer latency between HL and NSCLC diagnoses (P = .015).

CONCLUSIONS

Compared with patients who had de novo NSCLC, HL survivors experienced a significant 30% to 60% decrease in OS after an NSCLC diagnosis. Further research is needed to not only elucidate the clinical-biologic underpinnings of NSCLC after HL, including the influence of previous HL treatment, but also to define the role of lung cancer screening in selected patients.

Dose-response relationship for breast cancer induction at radiotherapy dose

Purpose

Cancer induction after radiation therapy is known as a severe side effect. It is therefore of interest to predict the probability of second cancer appearance for the patient to be treated including breast cancer.

Materials and methods

In this work a dose-response relationship for breast cancer is derived based on

(i) the analysis of breast cancer induction after Hodgkin's disease,

(ii) a cancer risk model developed for high doses including fractionation based on the linear quadratic model, and

(iii) the reconstruction of treatment plans for Hodgkin's patients treated with radiotherapy,

(iv) the breast cancer induction of the A-bomb survivor data.

Results

The fitted model parameters for an α/β = 3 Gy were α = 0.067Gy^-1 and R = 0.62. The risk for breast cancer is according to this model for small doses consistent with the finding of the A-bomb survivors, has a maximum at doses of around 20 Gy and drops off only slightly at larger doses. The predicted EAR for breast cancer after radiotherapy of Hodgkin's disease is 11.7/10000PY which can be compared to the findings of several epidemiological studies where EAR for breast cancer varies between 10.5 and 29.4/10000PY. The model was used to predict the impact of the reduction of radiation volume on breast cancer risk. It was estimated that mantle field irradiation is associated with a 3.2-fold increased risk compared with mediastinal irradiation alone, which is in agreement with a published value of 2.7. It was also shown that the modelled age dependency of breast cancer risk is in satisfying agreement with published data.

Conclusions

The dose-response relationship obtained in this report can be used for the prediction of radiation induced secondary breast cancer of radiotherapy patients.

Exposure to ionizing radiation and development of bone sarcoma: new insights based on atomic-bomb survivors of Hiroshima and Nagasaki

BACKGROUND

Radiation-induced bone sarcoma has been associated with high doses of ionizing radiation from therapeutic or occupation-related exposures. However, the development of bone sarcoma following exposure to lower doses of ionizing radiation remains speculative.

METHODS

A cohort analysis based on the Life Span Study (n = 120,321) was performed to assess the development of bone sarcoma in atomic-bomb survivors of Hiroshima and Nagasaki followed from 1958 to 2001. The excess relative risk per gray of ionizing radiation absorbed by the bone marrow was estimated. Additional subject demographic, survival, and clinical factors were evaluated.

RESULTS

Nineteen cases of bone sarcoma (in eleven males and eight females) were identified among the 80,181 subjects who met the inclusion criteria, corresponding to an incidence of 0.9 per 100,000 person-years. The mean ages at the time of the bombing and at diagnosis were 32.4 and 61.6 years, respectively. The mean bone marrow dose was 0.43 Gy. Osteosarcoma was the most commonly identified bone sarcoma. The most common bone sarcoma site was the pelvis. The overall unadjusted five-year survival rate was 25%. A dose threshold was found at 0.85 Gy (95% confidence interval, 0.12 to 1.85 Gy), with a linear dose-response association above this threshold. The linear slope equaled an excess relative risk of 7.5 per Gy (95% confidence interval, 1.34 to 23.14 per Gy) in excess of 0.85 Gy.

CONCLUSIONS

On the basis of what we believe is one of the longest and largest prospective studies assessing the development of bone sarcoma in individuals exposed to ionizing radiation, it appears that the development of radiation-induced bone sarcoma may be associated with exposure to much lower doses of ionizing radiation than have previously been reported. Such new insights may potentially improve bone sarcoma prevention measures and broaden our understanding of the role of ionizing radiation from various sources on the development of malignant tumors. This study stresses the need to become increasingly aware of the various health risks that may be attributable to even low levels of ionizing radiation exposure.

LEVEL OF EVIDENCE

Prognostic Level I. See Instructions to Authors for a complete description of levels of evidence.

Locoregional treatment for breast carcinoma after Hodgkin's lymphoma: the breast conservation option

PURPOSE

To report clinical and pathologic characteristics and outcome of breast cancer (BC) after irradiation for Hodgkin's lymphoma (HL) in women treated at the Institut Curie, with a special focus on the breast-conserving option.

METHODS AND MATERIALS

Medical records of 72 women who developed either ductal carcinoma in situ or Stage I-III invasive carcinoma of the breast after HL between 1978 and 2009 were retrospectively reviewed.

RESULTS

Median age at HL diagnosis was 23 years (range, 14-53 years). Median total dose received by the mediastinum was 40 Gy, mostly by a mantle-field technique. Breast cancers occurred after a median interval of 21 years (range, 5-40 years). Ductal invasive carcinoma and ductal carcinoma in situ represented, respectively, 51 cases (71%) and 14 cases (19%). Invasive BCs consisted of 47 cT0-2 tumors (82%), 5 cN1-3 tumors (9%), and 20 Grade 3 tumors (35%). Locoregional treatment for BCs consisted of mastectomy with (3) or without (36) radiotherapy in 39 patients and lumpectomy with (30) or without (2) adjuvant radiotherapy in 32 patients. The isocentric lateral decubitus radiation technique was used in 17 patients after breast-conserving surgery (57%). With a median follow-up of 7 years, 5-year overall survival rate and locoregional control rate were, respectively, 74.5% (95% confidence interval [CI], 64-88%) and 82% (95% CI, 72-93%) for invasive carcinoma and 100% (95% CI, 100 -100%) and 92% (95% CI, 79-100%) for in situ carcinoma. In patients with invasive tumors, the 5-year distant disease-free survival rate was 79% (95% CI, 69-91%), and 13 patients died of progressive BC. Contralateral BC was diagnosed in 10 patients (14%).

CONCLUSIONS

Breast-conserving treatment can be an option for BCs that occur after HL, despite prior thoracic irradiation. It should consist of lumpectomy and adjuvant breast radiotherapy with use of adequate techniques, such as the lateral decubitus isocentric position, to protect the underlying heart and lung.

Characteristics and outcomes of breast cancer in women with and without a history of radiation for Hodgkin's lymphoma: a multi-institutional, matched cohort study

PURPOSE

To compare characteristics and outcomes of breast cancer in women with and without a history of radiation therapy (RT) for Hodgkin's lymphoma (HL).

PATIENTS AND METHODS

Women with breast cancer diagnosed from 1980 to 2006 after RT for HL were identified from eight North American hospitals and were matched three-to-one with patients with sporadic breast cancer by age, race, and year of breast cancer diagnosis. Information on patient, tumor and treatment characteristics, and clinical outcomes was abstracted from medical records.

RESULTS

A total of 253 patients with breast cancer with a history of RT for HL were matched with 741 patients with sporadic breast cancer. Median time from HL to breast cancer diagnosis was 18 years. Median age at breast cancer diagnosis was 42 years. Breast cancer after RT for HL was more likely to be detected by screening, was more likely to be diagnosed at an earlier stage, and was more likely to be bilateral at diagnosis. HL survivors had an increased risk of metachronous contralateral breast cancer (adjusted hazard ratio [HR], 4.3; 95% CI, 1.7 to 11.0) and death as a result of any cause (adjusted HR, 1.9; 95% CI, 1.1 to 3.3). Breast cancer-specific mortality was also elevated, but this difference was not statistically significant (adjusted HR, 1.6; 95% CI, 0.7 to 3.4).

CONCLUSION

In women with a history of RT for HL, breast cancer is diagnosed at an earlier stage, but these women are at greater risk for bilateral disease and are more likely to die as a result of causes other than breast cancer. Our findings support close follow-up for contralateral tumors in these patients and ongoing primary care to manage comorbid conditions.

Outcomes of patients with non-Hodgkin's lymphoma treated with Bexxar with or without external-beam radiotherapy

PURPOSE

To compare the efficacy and toxicity of external-beam radiotherapy (EBRT) to sites of bulky lymphadenopathy in patients with chemotherapy-refractory low-grade non-Hodgkin's lymphoma (NHL) immediately before receiving Bexxar (tositumomab and (131)I) vs. in patients receiving Bexxar alone for nonbulky disease.

METHODS AND MATERIALS

Nineteen patients with chemotherapy-refractory NHL were treated with Bexxar at our institution (University of Florida, Gainesville, FL) from 2005 to 2008. Seventeen patients had Grade 1-2 follicular lymphoma. Ten patients received a median of 20 Gy in 10 fractions to the areas of clinical involvement, immediately followed by Bexxar (EBRT + Bexxar); 9 patients received Bexxar alone. The median tumor sizes before EBRT + Bexxar and Bexxar alone were 4.8 cm and 3.3 cm, respectively. All 5 patients with a tumor diameter >5 cm were treated with EBRT + Bexxar. A univariate analysis of prognostic factors for progression-free survival (PFS) was performed.

RESULTS

The median follow-up was 2.3 years for all patients and 3.1 years for 12 patients alive at last follow-up. Of all patients, 79% had a partial or complete response; 4 of the 8 responders in the EBRT + Bexxar group achieved a durable response of over 2 years, including 3 of the 5 with tumors >5 cm. Three of 9 patients treated with Bexxar alone achieved a durable response over 2 years. Actuarial estimates of 3-year overall survival and PFS for EBRT + Bexxar and Bexxar alone were 69% and 38% and 62% and 33%, respectively. The median time to recurrence after EBRT + Bexxar and Bexxar alone was 9 months. Having fewer than 4 involved lymph-node regions was associated with superior PFS at 3 years (63% vs. 18%). There was no Grade 4 or 5 complications.

CONCLUSIONS

Adding EBRT immediately before Bexxar produced PFS equivalent to that with Bexxar alone, despite bulkier disease. Hematologic toxicity was not worsened. EBRT combined with Bexxar adds a safe and effective therapeutic treatment for managing recurrent low-grade follicular NHL.

Long-Term Complications of Lymphoma and Its Treatment

As a result of therapeutic advances, there is a growing population of survivors of both Hodgkin's lymphoma (HL) and non-Hodgkin's lymphoma (NHL). A thorough understanding of the late effects of cancer and its treatment, including the risk of developing a second malignancy and non-neoplastic complications, most notably cardiac disease, is essential for the proper long-term follow-up care of these patients. For HL survivors cured in the past 5 decades, a large body of literature describes a range of long-term effects, many of which are related to extent of treatment. These studies form the basis for many of the follow-up recommendations developed for HL survivors. As HL therapy continues to evolve, however, with an emphasis toward treatment reduction, in particular for early-stage disease, it will be important to rigorously observe this new generation of patients long term to document and quantify late effects associated with modern treatments. Although data on late effects after NHL therapy have recently emerged, the formulation of structured follow-up plans for this heterogeneous group of survivors is challenging, given the highly variable natural history, treatments, and overall prognosis. However, the chemotherapy and radiation therapy approaches for some types of NHL are similar to that for HL; thus, some of the follow-up guidelines for patients with HL may also be transferrable to selected survivors of NHL. Additional work focused on treatment-related complications after NHL will facilitate the development of follow-up programs, as well as treatment refinements to minimize late effects in patients with various types of NHL.

Scar carcinoma of the lung: a historical perspective

Lung scar carcinoma (SC) was first described by Friedrich in 1939 as a type of lung cancer that originates around peripheral scars in the lung. Scarring in the lung can result from a variety of infections, injuries, and lung diseases. Scars can also be due to repeated episodes of tumor necrosis and healing. SCs are typically found as subpleural adenocarcinomas with retraction or puckering of the overlying pleura. They were considered a histologic curiosity that was promoted for decades until doubts about their existence were raised in the 1980s. Finding type III collagen, type V collagen, and myofibroblasts characteristic of fibrosis in the scars, finally reversed the original SC concept. The presence of type III collagen and extracellular matrix suggested an ongoing fibrosing process secondary to host response to the neoplasm. The high concentration of type III collagen in SC indicates that the fibrous tissue is in an active immature state compared with noneuplastic fibrous tissue, which is mature and contains type I and type V collagen. A recent cohort analysis of data from the PLCO (Prostate, Lung, Colorectal and Ovarian) cancer screening trial demonstrated a correlation between the presence of scar and the development of carcinoma, but the causation of this association has to be determined by future studies. The role of inflammation, infections, and smoking in the development of cancer is discussed in this article. Additional research is necessary to determine if lung scarring detected by imaging requires clinical monitoring in the context of the development of lung cancer when a defined set of risk factors is identified.

Autologous transplant for primary mediastinal B-cell lymphoma

Primary mediastinal large B-cell lymphoma (PMBCL) is a subtype of lymphoma that shares similarities with diffuse large B-cell lymphoma and with classic Hodgkin's lymphoma. The current study evaluates the use of autologous stem cell transplant (ASCT) as part of initial therapy in a cohort of patients with PMBCL treated between 1985 and 2006. The study demonstrates excellent survival and progression-free survival for patients in complete remission (CR) at ASCT, and for those achieving CR after ASCT. It also shows a benefit to administration of involved-field radiation therapy. However, front-line therapy has evolved considerably since these patients were treated. Dose-dense chemotherapy regimens show excellent results without transplant and the incorporation of rituximab in the treatment may have further improved outcomes. Given these excellent results, ASCT should not currently be used in patients in first CR, but ASCT remains the treatment of choice in relapsed and refractory PMBCL. Similarly, radiotherapy is unnecessary in patients in first CR but is probably useful in patients with residual active mass.

Using epidemiology and genomics to understand osteosarcoma etiology

Osteosarcoma is a primary bone malignancy that typically occurs during adolescence but also has a second incidence peak in the elderly. It occurs most commonly in the long bones, although there is variability in location between age groups. The etiology of osteosarcoma is not well understood; it occurs at increased rates in individuals with Paget disease of bone, after therapeutic radiation, and in certain cancer predisposition syndromes. It also occurs more commonly in taller individuals, but a strong environmental component to osteosarcoma risk has not been identified. Several studies suggest that osteosarcoma may be associated with single nucleotide polymorphisms in genes important in growth and tumor suppression but the studies are limited by sample size. Herein, we review the epidemiology of osteosarcoma as well as its known and suspected risk factors in an effort to gain insight into its etiology.

Human immunodeficiency and Hodgkin lymphoma

Presentation of Hodgkin lymphoma (HL) is distinctive in the infected individual being more advanced, accompanied by B symptoms and the presence of extranodal disease particularly lymphadenopathy of the head and neck. Bone marrow involvement may be found in over 50% of cases. Virtually all co express gamma-herpesvirus. Phenotypically there is prominence of the mixed-cellularity and lymphocyte depleted histopathologic subtypes that define an aggressive clinical course in comparison to other variants. Prior to the induction of cART, median survival was only 1-2 years. Notably the first chemotherapy trial using ABVD (doxorubicin, bleomycin, vinblastine, and dacarbazine) in 21 patients, without treating the viral infection, resulted in a 43% complete remission rate accompanied by severe haematological toxicities but did not extend median survival with this being 1.5 years matching the negative cases. Significant change accompanied concomitant anti-retroviral therapy that could be given safely even with dose intensive regimens exemplified by BEACOPP (bleomycin, etoposide, doxorubicin, cyclophosphamide, vincristine, procarbazine, and prednisone) in 12 patients or the Stanford V regimen (doxorubicin, vinblastine, mechlorethamine, etoposide, vincristine, bleomycin, prednisone) coupled with involved-field radiation for bulky disease studied in 59 patients. BEACOPP extended overall survival (OS) to 83% at 2 years. A similar trend was seen when using the Stanford V regimen with an OS rate of 51% at 3 years, disease-free survival (DFS) of 68% and freedom from progression (FFP) in 60%. Additional benefits accrued from supportive care with stimulatory peptides such as G-CSF and when combined with bacterial prophylaxis results approached that found in the uninfected reference group. Current consensus holds this particular lymphoma as still among the non-AIDS defining cancers being lung, stomach, liver or anal despite these having recently gained more attention as several of these neoplasms may be occurring more commonly in the era of cART. While the relative risk of developing a non-AIDS-defining neoplasm in HIV-infected persons on the average is 2-3 times, the risk for developing HL in HIV-infected cases impressively ranges between 5 and 25 times when compared to the general population. Based on the precedent in which Kaposi sarcoma and the non-Hodgkin lymphomas distinctively alter the course of this retroviral infection in a way indistinguishable from concurrent Hodgkin lymphoma we propose that this entity be similarly regarded and the hypothesis tested in large randomised prospective study.

Breast cancer occurred after Hodgkin's disease: clinico-pathological features, treatments and outcome: analysis of 214 cases

BACKGROUND

Secondary tumours (ST) represent a major concern in survivors of Hodgkin's disease (HD). Breast cancer (BC) is the most frequent ST among young treated women.

MATERIAL AND METHODS

One hundred and eighty-nine women treated for HD by radiotherapy (RT) and/or chemotherapy (CT) subsequently developed 214 BCs.

RESULTS

Median age at HD diagnosis was 25 years (34% were less than 20). Median interval between HD and BC was 18.6 years, with a 42-year median age at first BC. According to the TNM classification, there were 30 (14%) T0 (non palbable lesions), 86 (40%) T1, 56 (26%) T2, 13 (6%) T3T4 and 29 (14%) Tx. There were 25 (13.2%) contralateral BC. 160 (75%) and 15 (7%) tumours were infiltrating ductal and lobular carcinomas, 7 (3.3%) were other subtypes and 27 (22%) DCIS. The rate of axillary nodal involvement was 32%. Among 203 operated tumours, 79 (39%) were treated by breast conserving surgery (BCS), with RT in 56 (71%) cases. CT and hormonal treatment were delivered in 51% and 45% of the patients. With a 50-month median follow-up, local recurrence occurred in 12% of the tumours (9% after mastectomy, 21% after lumpectomy alone and 13.7% after lumpectomy with RT). Metastasis occurred in 47 (26%) patients. The risk factors were pN+, pT, high SBR grade and young age (< 50 years). The ten-year overall and specific survival rates were 53% and 63.5%, respectively. The ten-year specific survival rates were 79% for pT0T1T2, 48% for pT3T4 (p = 0.0002) and 79% for pN0 versus 38.5% for pN+ (p = 0.00026). Among 67 deaths, 43 (73%) were due to BC.

CONCLUSION

Patients and physicians should be aware that BC is the most frequent secondary tumour in young women treated for HD. The new RT modalities (lower doses and involved fields) may decrease the risk in the future. However, these women require a careful monitoring as from 8 to 10 years after HD treatment, combining mammography, ultrasound and MRI according to several ongoing studies. BC with whole breast irradiation is feasible in some selected cases.

Chemotherapy alone versus chemotherapy plus radiotherapy for early stage Hodgkin lymphoma

BACKGROUND

Combined modality treatment (CMT) consisting of chemotherapy followed by localised radiotherapy is standard treatment for patients with early stage Hodgkin lymphoma (HL). However, due to long term adverse effects such as secondary malignancies, the role of radiotherapy has been questioned recently and some clinical study groups advocate chemotherapy only for this indication.

OBJECTIVES

We performed a systematic review with meta-analysis of randomised controlled trials (RCTs) comparing chemotherapy alone with CMT in patients with early stage Hodgkin lymphoma with respect to response rate, progression-free survival (alternatively tumour control) and overall survival (OS).

SEARCH STRATEGY

We searched MEDLINE, EMBASE and CENTRAL as well as conference proceedings from January 1980 to November 2010 for randomised controlled trials comparing chemotherapy alone to the same chemotherapy regimen plus radiotherapy. 

SELECTION CRITERIA

Randomised controlled trials comparing chemotherapy alone with CMT in patients with early stage HL. Trials in which the chemotherapy differed between treatment arms were excluded. Trials with more than 20% of patients in advanced stage were also excluded.

DATA COLLECTION AND ANALYSIS

Effect measures used were hazard ratios (HR) for tumour control and OS as well as relative risks for response rates. Two review authors independently extracted data and assessed quality of trials. We contacted study authors to obtain missing information. Since none of the trials reported progression-free survival according to our definitions, all similar outcomes were evaluated as tumour control.

MAIN RESULTS

Five RCTs involving 1245 patients were included. The HR was 0.41 (95% confidence interval (CI) 0.25 to 0.66) for tumour control and 0.40 (95% CI 0.27 to 0.61) for OS for patients receiving CMT compared to chemotherapy alone. Complete response rates were similar between treatment groups. In sensitivity analyses another six trials were included that did not fulfil the inclusion criteria of our protocol but were considered relevant to the topic. These trials underlined the results of the main analysis.

AUTHORS' CONCLUSIONS

Adding radiotherapy to chemotherapy improves tumour control and overall survival in patients with early stage Hodgkin lymphoma.

Late effects in the era of modern therapy for Hodgkin lymphoma

Extended-field and subtotal nodal radiation therapy (RT), developed in the 1960s, was the first reliably curative treatment for early-stage Hodgkin lymphoma (HL). However, the large volume of normal tissue irradiated resulted in significant delayed toxicity, including cardiac disease and second cancers (SCs). The 30-year cumulative incidence of heart disease among adult survivors receiving 40-45 Gy of extended-field or mantle RT is approximately 30%; the incidence of SCs is similar. Improving disease control while reducing the toxicity of treatment has been a major objective of HL trials for more than 2 decades. Contemporary involved-field RT (IFRT) reduces irradiated volumes and produces significant reductions in normal tissue dose compared with historic treatments. Recent data indicate that, compared with mantle RT, IFRT reduces the relative risk of breast cancer among young females receiving mediastinal RT by approximately 60% and also reduces cardiac dose. The recent transition to involved-node RT allows further reductions in normal tissue dose. Response-adapted therapy is being evaluated in clinical trials as a means of identifying those patients most likely to benefit from treatment reduction or intensification, enhanced screening will facilitate early intervention to reduce the clinical burden of late effects, and there is increasing interest in elucidating the genetic correlates of treatment toxicity.

Effect of organ size and position on out-of-field dose distributions during radiation therapy

Mantle field irradiation has historically been the standard radiation treatment for Hodgkin lymphoma. It involves treating large regions of the chest and neck with high doses of radiation (up to 30 Gy). Previous epidemiological studies on the incidence of second malignancies following radiation therapy for Hodgkin lymphoma have revealed an increased incidence of second tumors in various organs, including lung, breast, thyroid and digestive tract. Multiple other studies, including the Surveillance, Epidemiology and End Results, indicated an increased incidence in digestive tract including stomach cancers following mantle field radiotherapy. Assessment of stomach dose is challenging because the stomach is outside the treatment field but very near the treatment border where there are steep dose gradients. In addition, the stomach can vary greatly in size and position. We sought to evaluate the dosimetric impact of the size and variable position of the stomach relative to the field border for a typical Hodgkin lymphoma mantle field irradiation. The mean stomach dose was measured using thermoluminescent dosimetry for nine variations in stomach size and position. The mean doses to the nine stomach variations ranged from 0.43 to 0.83 Gy when 30 Gy was delivered to the treatment isocenter. Statistical analyses indicated that there were no significant differences in the mean stomach dose when the stomach was symmetrically expanded up to 3 cm or shifted laterally (medial, anterior or posterior shifts) by up to 3 cm. There was, however, a significant (P > 0.01) difference in the mean dose when the stomach was shifted superiorly or inferiorly by ≥2.5 cm.

Long-term survival among patients with Hodgkin's lymphoma who developed breast cancer: a population-based study

PURPOSE

The increased risk of breast cancer (BC) among women receiving chest radiotherapy for Hodgkin's lymphoma (HL) is well-established. However, there are no large population-based studies that describe overall survival (OS) and cause-specific survival (CSS) compared with women with first primary BC.

METHODS

For 298 HL survivors who developed BC (HL-BC group) and 405,223 women with a first or only BC (BC-1 group), actuarial OS and CSS were compared, accounting for age, BC stage, hormone receptor status, sociodemographic status, radiation for HL, and other variables. All patients were derived from the population-based Surveillance, Epidemiology, and End Results program.

RESULTS

OS among patients with HL-BC was significantly inferior that of to patients with BC-1: 15-year OS was 48% versus 69% (P < .0001) for localized BC, and 33% versus 43% (P < .0001) for regional/distant BC. Patients with HL-BC had a significantly increased seven-fold risk (P < .0001) of death from other cancers (ie, not HL or BC) compared with patients with BC-1. Mortality from heart disease among patients with HL-BC with either localized or regional/distant disease was also significantly increased (hazard ratio = 2.22, P = .04; and hazard ratio = 4.28, P = .02, respectively) compared with patients with BC-1. Although 10-year BC-CSS was similar for patients with HL-BC and BC-1 with regional/distant disease, it was inferior for patients with localized BC (82% v 88%, respectively; P = .002).

CONCLUSION

Women with HL may survive a subsequent diagnosis of BC, only to experience significant excesses of death from other primary cancers and cardiac disease. Greater awareness of screening for cardiac disease and subsequent primary cancers in patients with HL-BC is warranted.

Reduced versus full doses of irradiation after 3 cycles of combined doxorubicin, bleomycin, vinblastine, and dacarbazine in early stage Hodgkin lymphomas: results of a randomized trial

BACKGROUND

The combination of 3 cycles of doxorubicin, bleomycin, vinblastine, and dacarbazine (ABVD) and a tailored, extended irradiation schedule has been used to treat patients with early Hodgkin lymphoma (HL) in the authors' group since 1981. The randomized H97-E trial (1997-2004) was designed to assess the impact of a slightly reduced irradiation dose on the freedom from treatment failure (FFTF) rate.

METHODS

Patients with supradiaphragmatic HL at clinical stages I and II who had </=2 affected lymph node areas and a mediastinal mass ratio <0.33 were randomized into an experimental arm (EA) and a control arm (CA). Patients in the EA received 3 cycles of ABVD followed by irradiation at 36 grays (Gy) to initially involved sites and 24 Gy to adjacent sites, the upper infradiaphragmatic area, and the spleen. Patients in the CA received the same chemotherapy regimen and the same irradiation given at doses of 40 Gy and 30 Gy, respectively. Two hundred two patients who had received the CA treatment in 2 previous trials served as a historic control group (HCG).

RESULTS

The 10-year FFTF and overall survival rates were similar for the 89 patients in the EA (88.6% and 97.8%, respectively), for the 99 patients in the CA (92.6% and 95%, respectively), and for the 202 patients in the HCG (91.9% and 92.9%, respectively). Surprisingly, the 10-year incidence of severe or fatal complications was nil in the EA but reached 15.5% in the CA (P < .003) and 11.1% in the HCG.

CONCLUSIONS

Slightly lowering the radiation dose did not have an impact on the excellent cure rate among patients with early HL but significantly reduced the rate of long-term, radiation-induced complications.

Screening and surveillance for second malignant neoplasms in adult survivors of childhood cancer: a report from the childhood cancer survivor study

BACKGROUND

Survivors of childhood cancer may develop a second malignant neoplasm during adulthood and therefore require regular surveillance.

OBJECTIVE

To examine adherence to population cancer screening guidelines by survivors at average risk for a second malignant neoplasm and adherence to cancer surveillance guidelines by survivors at high risk for a second malignant neoplasm.

DESIGN

Retrospective cohort study.

SETTING

The Childhood Cancer Survivor Study (CCSS), a 26-center study of long-term survivors of childhood cancer that was diagnosed between 1970 and 1986.

PATIENTS

4329 male and 4018 female survivors of childhood cancer who completed a CCSS questionnaire assessing screening and surveillance for new cases of cancer.

MEASUREMENTS

Patient-reported receipt and timing of mammography, Papanicolaou smear, colonoscopy, or skin examination was categorized as adherent to the U.S. Preventive Services Task Force guidelines for survivors at average risk for breast or cervical cancer or the Children's Oncology Group guidelines for survivors at high risk for breast, colorectal, or skin cancer as a result of cancer therapy.

RESULTS

In average-risk female survivors, 2743 of 3392 (80.9%) reported having a Papanicolaou smear within the recommended period, and 140 of 209 (67.0%) reported mammography within the recommended period. In high-risk survivors, rates of recommended mammography among women were only 241 of 522 (46.2%) and the rates of colonoscopy and complete skin examinations among both sexes were 91 of 794 (11.5%) and 1290 of 4850 (26.6%), respectively.

LIMITATIONS

Data were self-reported. Participants in the CCSS are a selected group of survivors, and their adherence may not be representative of all survivors of childhood cancer.

CONCLUSION

Female survivors at average risk for a second malignant neoplasm show reasonable rates of screening for cervical and breast cancer. However, surveillance for new cases of cancer is very low in survivors at the highest risk for colon, breast, or skin cancer, suggesting that survivors and their physicians need education about their risks and recommended surveillance.

PRIMARY FUNDING SOURCE

The National Cancer Institute, National Institutes of Health, and the American Lebanese Syrian Associated Charities.

Risk of breast cancer according to clinicopathologic features among long-term survivors of Hodgkin's lymphoma treated with radiotherapy

Background:

It is unknown whether breast cancer (BC) characteristics among young women treated with radiotherapy (RT) for Hodgkin's lymphoma (HL) differ from sporadic BC.

Methods:

Using population-based data, we calculated BC risk following HL according to clinicopathologic features.

Results:

Compared with BC in the general population, risks of oestrogen receptor (ER)-positive/progesterone receptor (PR)-positive and ER-negative/PR-negative BC in young, irradiated HL survivors were increased five-fold (95% confidence interval (CI)=3.81–6.35) and nine-fold (95% CI=6.93–12.25), respectively. Among 15-year survivors, relative risk of ER-negative/PR-negative BC exceeded by two-fold (P=0.002) than that of ER-positive/PR-positive BC.

Conclusion:

Radiotherapy may disproportionately contribute to the development of BC with adverse prognostic features among young HL survivors.

Predicted risk of radiation-induced cancers after involved field and involved node radiotherapy with or without intensity modulation for early-stage hodgkin lymphoma in female patients

PURPOSE

To assess the excess relative risk (ERR) of radiation-induced cancers (RIC) in female patients with Hodgkin lymphoma (HL) female patients treated with conformal (3DCRT), intensity modulated (IMRT), or volumetric modulated arc (RA) radiation therapy.

METHODS AND MATERIALS

Plans for 10 early-stage HL female patients were computed for 3DCRT, IMRT, and RA with involved field RT (IFRT) and involvednode RT (INRT) radiation fields. Organs at risk dose--volume histograms were computed and inter-compared for IFRT vs. INRT and 3DCRT vs. IMRT/RA, respectively. The ERR for cancer induction in breasts, lungs, and thyroid was estimated using both linear and nonlinear models.

RESULTS

The mean estimated ERR for breast, lung, and thyroid were significantly lower (p < 0.01) with INRT than with IFRT planning, regardless of the radiation delivery technique used, assuming a linear dose-risk relationship. We found that using the nonlinear model, the mean ERR values were significantly (p < 0.01) increased with IMRT or RA compared to those with 3DCRT planning for the breast, lung, and thyroid, using an IFRT paradigm. After INRT planning, IMRT or RA increased the risk of RIC for lung and thyroid only.

CONCLUSIONS

In this comparative planning study, using a nonlinear dose--risk model, IMRT or RA increased the estimated risk of RIC for breast, lung, and thyroid for HL female patients. This study also suggests that INRT planning, compared to IFRT planning, may reduce the ERR of RIC when risk is predicted using a linear model. Observing the opposite effect, with a nonlinear model, however, questions the validity of these biologically parameterized models.

Treating prostate cancer with radiotherapy

This Review focuses on the adverse effects of radical radiotherapy for localized prostate cancer. The adverse effects are described in the context of alternative treatment modalities. First, we consider the methodological issues that make comparison between the different treatment modalities problematic. Such issues include differences in baseline levels of urinary, bowel and sexual dysfunction, the importance of using patient-reported outcomes and the distinction between actuarial and prevalence rates of treatment-related toxic effects. Second, we describe the pattern of adverse effects that occur over time after radiotherapy. Here, we focus on evidence for a beneficial effect of radiotherapy on some urinary symptoms, and the controversy regarding the risk of secondary malignancy. Third, predictors of radiation toxicity are discussed. Accurate prediction of radiotherapy toxicity would be an invaluable tool for treatment individualization. It is noteworthy that the data on the adverse effects of prostate radiotherapy necessarily relate to treatment as it was delivered in the past. It is likely that recent technical advances, such as intensity modulation and image guidance, will further improve the toxicity profile of prostate radiotherapy.

Class I histone deacetylases 1, 2 and 3 are highly expressed in classical Hodgkin's lymphoma

OBJECTIVE

HDAC inhibitors (HDI) are anti-neoplastic drugs with preliminary successful clinical applications in Hodgkin's lymphoma (HL). Systematic investigations of HDAC expression in HL, based on histology and immunohistochemistry are yet rare.

RESEARCH DESIGN/METHODS

We investigated the expression of HDAC1, 2 and 3 in 283 HL on tissue microarrays.

MAIN OUTCOME MEASURES

Expression of HDAC isoforms was scored in Hodgkin and Reed-Sternberg cells (HRSC) and background infiltrate and compared with freedom of treatment failure (FTF) in 118 cases, for which all data was available.

RESULTS

All analyzable HL expressed the HDAC isoforms 2 (n = 194) and 3 (n = 207) in over 50%, mostly 100%, of HRSC and almost all background lymphocytes. HDAC1 was expressed in 169 of 179 analyzable HL in a mean of 82% and in 172 out of 179 analyzable cases in a mean of 83% of infiltrating lymphocytes. HDAC1 of below 75% in HRSC correlated with worse FTF with 16 out of 32 events, compared with 16 out of 82 in cases with over 75% HDAC1-expressing HRSC.

CONCLUSION

HDAC isoforms 1, 2 and 3 are highly expressed in HL. In addition, decreased HDAC1 expression is accompanied by worse outcome in HL.

Dose-response relationship for lung cancer induction at radiotherapy dose

Cancer induction after radiation therapy is a severe side effect. It is therefore of interest to predict the probability of second cancer appearance for the treated patient. Currently there is large uncertainty about the shape of the dose-response relationship for carcinogenesis for most cancer types at high dose levels. In this work a dose-response relationship for lung cancer is derived based on (i) the analysis of lung cancer induction after Hodgkin's disease, (ii) a cancer risk model developed for high doses including fractionation based on the linear quadratic model, and (iii) the reconstruction of treatment plans for Hodgkin's patients treated with radiotherapy. The fitted model parameters for an α/β=3 Gy were α=0.061Gy(-1) and R=0.84. The value for α is in agreement with analysis of normal tissue complications of the lung after radiation therapy. The repopulation/repair parameter R is large, but seems to be characteristic for lung tissue which is sensitive with regard to fractionation. Lung cancer risk is according to this model for small doses consistent with the finding of the A-bomb survivors, has a maximum at doses of around 15 Gy and drops off only slightly at larger doses. The predicted EAR for lung after radiotherapy of Hodgkin's disease is 18.4/10000PY which can be compared to the findings of several epidemiological studies were EAR for lung varies between 9.7 and 21.5/10000PY.

Pelvic radiotherapy and the risk of secondary leukemia and multiple myeloma

BACKGROUND

Although several studies had examined secondary malignancies in patients with specific primary tumor types, to the authors' knowledge there are very few data examining the long-term sequelae of pelvic radiation as a whole. The goal of the current study was to examine the risk of treatment-associated leukemia and multiple myeloma in patients treated with pelvic radiotherapy.

METHODS

Patients with invasive tumors of the vulva, cervix, uterus, anus, and rectosigmoid treated from 1973 to 2005 and recorded in the Surveillance, Epidemiology, and End Results (SEER) database were analyzed. Patients were stratified based on receipt of pelvic radiotherapy. The incidence of secondary leukemia (except chronic lymphocytic leukemia) and multiple myeloma were examined. Multivariate Cox proportional hazards models and Kaplan-Meier curves were constructed to examine the association between pelvic radiation and the development of subsequent hematologic malignancies.

RESULTS

A total of 199,268 individuals, including 66,896 (34%) who received pelvic radiotherapy and 132,372 (66%) not treated with radiation, were identified. In a Cox proportional hazards model adjusting for other risk factors, post-treatment leukemia was increased by 72% (hazard ratio [HR], 1.72; 95% confidence interval [95% CI], 1.37-2.15) in the patients who received pelvic radiotherapy. The risk of secondary leukemia peaked at 5 to 10 years after primary treatment (HR, 1.85; 95% CI, 1.40-2.44) and remained elevated even 10 to 15 years after initial treatment (HR, 1.50; 95% CI, 1.03-2.18). There was no significant association between radiation and the development of multiple myeloma (HR, 1.08; 95% CI, 0.81-1.44).

CONCLUSIONS

Pelvic radiation was associated with an increased risk of secondary leukemia but did not appear to increase the risk of multiple myeloma.

Secondary malignancies across the age spectrum

Development of a second malignancy is one of the most serious late effects in survivors of both childhood and adult-onset cancers. Patterns of second malignancy risk across the age spectrum can differ in terms of the types of second malignancies observed, magnitude of the risks, the latency period, associated risk factors, and modifying influences. Potential explanations for the varying risk patterns by age include differences in susceptibility of individual tissue/organ to carcinogenesis based on stage of development and level of tissue maturity, microenvironment, attained age, and lifestyle factors. A thorough understanding of these differences is essential when considering treatment modifications in newly diagnosed cancer patients who are aimed at reducing the risk of second malignancy and other late effects without compromising cure. Moreover, an understanding of the variations in second cancer risk according to age at treatment is important in customizing patient follow-up.

Hodgkin's Lymphoma in Adolescents Treated With Adult Protocols: A Report From the German Hodgkin Study Group

Purpose

The standard of care for adolescent patients with Hodgkin's lymphoma (HL) is undefined, particularly the choice between pediatric and adult protocols. Thus, we compared risk factors and outcome of adolescents and young adults treated within study protocols of the German Hodgkin Study Group (GHSG).

Patients and Methods

Three thousand seven hundred eighty-five patients treated within the GHSG studies HD4 to HD9 were analyzed; 557 patients were adolescents age 15 to 20 years, and 3,228 patients were young adults age 21 to 45 years.

Results

Large mediastinal mass and involvement of three or more lymph node areas were more frequent in adolescents (P < .001). The incidence of other risk factors did not differ significantly between age groups. With a median observation time of 81 months for freedom from treatment failure (FFTF) and 85 months for overall survival (OS), log-rank test showed no significant differences between age groups regarding FFTF (P = .305) and a superior OS (P = .008) for adolescents. Six-year estimates for FFTF and OS were 80% and 94%, respectively, for adolescents and 80% and 91%, respectively, for young adults. After adjustment for other predictive factors, Cox regression analysis revealed age as a significant predictor for OS (P = .004), with a higher mortality risk for young adults. Secondary malignancies were more common in young adults (P = .037).

Conclusion

Outcome of adolescent and young adult patients treated within GHSG study protocols is comparable. These data suggest that adult treatment protocols exhibit a safe and effective treatment option for adolescent patients with HL. However, longer follow-up, including assessment of late toxicity, is necessary for final conclusions.

Involved-node and involved-field volumetric modulated arc vs. fixed beam intensity-modulated radiotherapy for female patients with early-stage supra-diaphragmatic Hodgkin lymphoma: a comparative planning study

PURPOSE

A comparative treatment planning study was performed to compare volumetric-modulated arc (RA) to conventional intensity modulated (IMRT) for involved-field (IFRT) and involved-node (INRT) radiotherapy for Hodgkin lymphoma (HL).

METHODS AND MATERIALS

Plans for 10 early-stage HL female patients were computed for RA and IMRT. First, the planning target volume (PTV) coverage and organs at risk (OAR) dose deposition was assessed between the two modalities. Second, the OAR (lung, breast, heart, thyroid, and submandibular gland) dose-volume histograms were computed and compared for IFRT and INRT, respectively.

RESULTS

For IFRT and INRT, PTV coverage was equally homogeneous with both RA and IMRT. By and large, the OAR irradiation with IFRT planning was not significantly different between RA and IMRT. For INRT, doses computed for RA were, however, usually lower than those with IMRT, particularly so for the lung, breast, and thyroid. Regardless of RA and IMRT modalities, a significant 20-50% decrease of the OAR computed mean doses was observed with INRT when compared with IFRT (Breast D(Mean) 1.5 +/- 1.1 vs. 2.6 +/- 1.7 Gy, p < 0.01 and 1.6 +/- 1.1 vs. 2.9 +/- 1.9 Gy, p < 0.01 for RA and IMRT, respectively).

CONCLUSIONS

RA and IMRT results in similar level of dose homogeneity. With INRT but not IFRT planning, the computed doses to the PTV and OAR were usually higher and lower with RA when compared to IMRT. Regardless of the treatment modality, INRT when compared with IFRT planning led to a significant decrease in OAR doses, particularly so for the breast and heart.

Roles of radiation dose and chemotherapy in the etiology of stomach cancer as a second malignancy

PURPOSE

To evaluate the roles of radiation dose, chemotherapy, and other factors in the etiology of stomach cancer in long-term survivors of testicular cancer or Hodgkin lymphoma.

METHODS AND MATERIALS

We conducted a cohort study in 5,142 survivors of testicular cancer or Hodgkin lymphoma treated in the Netherlands between 1965 and 1995. In a nested case-control study, detailed information on treatment, smoking, gastrointestinal diseases, and family history was collected for 42 patients with stomach cancer and 126 matched controls. For each subject, the mean radiation dose to the stomach was estimated. Relative risks (RRs) of stomach cancer and the radiation-related excess relative risk (ERR) per gray were calculated by conditional logistic regression analysis.

RESULTS

The risk of stomach cancer was 3.4-fold increased compared with the general population. The risk increased with increasing mean stomach dose (p for trend, <0.001), at an ERR of 0.84 per Gy (95% confidence interval [CI], 0.12-15.6). Mean stomach doses of more than 20 Gy were associated with a RR of 9.9 (95% CI, 3.2-31.2) compared with doses below 11 Gy. The risk was 1.8-fold (95% CI, 0.8-4.4) increased after chemotherapy and 5.4-fold (95% CI, 1.2-23.9) increased after high doses of procarbazine (>or=13,000 mg) vs. <10,000 mg. The RR of smoking more than 10 cigarettes per day vs. no smoking was 1.6 (95% CI, 0.6-4.2).

CONCLUSIONS

Stomach cancer risk is strongly radiation dose dependent. The role of chemotherapy, particularly of procarbazine and related agents, needs further study, because of the relatively small numbers of chemotherapy-treated subjects.