Second malignancy risks after non-Hodgkin's lymphoma and chronic lymphocytic leukemia: differences by lymphoma subtype

Incidence of solid cancer in patients with follicular lymphoma

Introduction: Patients with follicular lymphoma (FL) have classically had a higher risk of solid cancers than the general population, but there is little data available in patients diagnosed and treated with modern day regimens.Material and methods: We conducted a retrospective multicenter study assessing the cumulative incidence of solid cancers other than nonmelanoma skin cancer in patients with FL between 1997 and 2016 and determined the standardized incidence ratio (SIR) to compare the incidence of solid cancers with that of the general populationResults: Among 1002 FL patients with 7 years of median follow-up, we found 74 solid cancers (most common breast [n = 19], lung and colon [n = 9 each]). The cumulative incidence was 3.8% at 5 years (95%CI 2.6-5.2) from the time of diagnosis and 4.4% at 5 years (95%CI 3.1-5.9%) from the time of front-line treatment. Although a comparison of all front-line strategies did not reveal differences in the risk of solid cancers, patients treated with anthracycline-based regimens appeared to have a lower incidence than those treated with bendamustine-based strategies (2.8% vs. 6.9%). However, patients receiving the former regimen were younger than the latter. On multivariable analysis, older age was correlated with the incidence of solid cancer and bendamustine-based treatment was of borderline significance. SIR for any solid cancer was 1.22 (95%CI 0.91-1.64), indicating no increased risk of solid cancer in patients with FL over that of the general population. However, on subgroup analyses, female patients treated with bendamustine-based strategies appeared to have a greater risk (SIR 3.85 [95%CI 1.45-10.27])Discussion: The incidence of solid cancer in this cohort of patients with FL was low and not greater than in the general population. However, the risk may be greater in female patients treated with bendamustine.

Trends in the risk of second primary malignancies among survivors of chronic lymphocytic leukemia

With improving survivorship in chronic lymphocytic leukemia (CLL), the risk of second primary malignancies (SPMs) has not been systematically addressed. Differences in risk for SPMs among CLL survivors from the Surveillance, Epidemiology, and End Results (SEER) database (1973–2015) were compared to risk of individual malignancies expected in the general population. In ~270,000 person-year follow-up, 6487 new SPMs were diagnosed with a standardized incidence ratio (SIR) of 1.2 (95% CI:1.17–1.23). The higher risk was for both solid (SIR 1.15; 95% CI:1.12–1.18) and hematological malignancies (SIR 1.61; 95% CI:1.5–1.73). The highest risk for SPMs was noted between 2 and 5 months after CLL diagnosis (SIR 1.57; 95% CI:1.41–1.74) and for CLL patients between 50- and 79-years-old. There was a significant increase in SPMs in years 2003–2015 (SIR 1.36; 95% CI:1.3–1.42) as compared to 1973–1982 (SIR 1.19; 95% CI:1.12–1.26). The risk of SPMs was higher in CLL patients who had received prior chemotherapy (SIR 1.38 95% CI:1.31–1.44) as compared to those untreated/treatment status unknown (SIR 1.16, 95% CI:1.13–1.19, p < 0.001). In a multivariate analysis, the hazard of developing SPMs was higher among men, post-chemotherapy, recent years of diagnosis, advanced age, and non-Whites. Active survivorship plans and long-term surveillance for SPMs is crucial for improved outcomes of patients with a history of CLL.

Risk and subtypes of secondary primary malignancies in diffuse large B-cell lymphoma survivors change over time based on stage at diagnosis

BACKGROUND

Previous studies have shown an increased risk of secondary primary malignancies (SPMs) after diffuse large B-cell lymphoma (DLBCL) treatment. Whether stage of DLBCL at diagnosis affects the subtypes of SPMs that occur has not been previously described.

METHODS

The Surveillance, Epidemiology, and End Results database was queried for patients aged >18 years diagnosed with primary DLBCL from 1973 to 2010 and categorized by early stage (ES) (stage I-II) or advanced stage (AS) (stage III-IV) disease. Differences in overall and location-specific SPM incidence by stage and time since diagnosis were assessed in 5-year intervals using a Fine-Gray hazards model. Overall survival was compared using the log-rank test. A Cox proportional hazards model was used to assess differences in survival.

RESULTS

In total, 26,038 patients with DLBCL were identified, including 14,724 with ES and 11,314 with AS disease. The median follow-up was 13.3 years. Overall, 13.0% of patients developed SPM, with a higher but nonsignificantly increased risk of SPM development in those who had ES disease compared with those who had AS disease (14% vs 11.6%; P = .14). During the first 5 years after diagnosis, patients who had ES disease had a higher risk of SPM than those who had AS disease, specifically colorectal, pancreas, breast, and prostate SPMs. During the period from 10 to 15 years after diagnosis, patients who had AS disease had a higher risk of SPM than those who had ES disease, specifically hematologic SPMs. Development of SPM was found to significantly increase the risk of death regardless of stage at diagnosis.

CONCLUSIONS

In this large, population-based study, distinctly different subtypes and temporal patterns of SPM development were identified based on stage of DLBCL at diagnosis. The current study merits consideration of tailored site-specific and time-specific surveillance for patients with DLBCL according to stage and time interval since diagnosis.

Population-based incidence of lymphomas in the French Nord-Pas-de-Calais region between 2001 and 2005: Annual estimations and spatial analysis

BACKGROUND

Non-Hodgkin's lymphomas (NHL) are the seventh most commonly diagnosed cancer in France. Nord-Pas-de-Calais is ranked as the region with the highest incidence of cancers and deaths by cancer in France. With its rich industrial past and its contrasted population densities between urban and rural territories, Nord-Pas-de-Calais represents a geographic area of interest to study the overall incidence of NHL and examine spatial variation of NHL incidence between the 170 cantons of the region.

METHODS

LYMPHONOR was a population-based multicentre retrospective study of patients residing in the Nord-Pas-de-Calais region and diagnosed with NHL between January 2001 and December 2005. Spatial distribution of NHL incidence in Nord-Pas-de-Calais was explored using two complementary approaches: adjusted smoothed standardised incidence ratio (SIR) and spatial scan statistics (detection of atypical clusters).

RESULTS

Between 2001 and 2005, 2132 new cases of NHL were diagnosed in the Nord-Pas-de-Calais region. In 2005, age-standardised NHL incidence rates were 10.2 and 7.0 cases per 100,000 person-years in male and female residents, respectively. No significant spatial disparities in NHL incidence were found within the Nord-Pas-de-Calais region. The age-adjusted smoothed SIR varied from 0.82 to 1.25 between cantons. Consistently, spatial scan statistics did not detect any significant atypical cluster of high NHL incidence.

CONCLUSION

Comparison with national data collected during the same period does not show an overincidence of NHL in the Nord-Pas-de-Calais region. In addition, no evidence for spatial heterogeneity and clustering of NHL incidence was found within this region. Future epidemiological research using large-scale registries is needed to better appraise spatial variation of NHL incidence in France and to investigate possible reasons for significant clusters.

Pentostatin, Cyclophosphamide, and Rituximab Followed by Alemtuzumab for Relapsed or Refractory Chronic Lymphocytic Leukemia: A Phase 2 Trial of the ECOG-Acrin Cancer Research Group (E2903)

Patients with relapsed/refractory (R/R) chronic lymphocytic leukemia (CLL) may benefit from salvage chemoimmunotherapy (CIT). To explore further the use of CIT in the pre-novel agent era, ECOG-ACRIN undertook a phase 2 trial (E2903) for R/R CLL utilizing pentostatin, cyclophosphamide, and rituximab (PCR) followed by a consolidation course of alemtuzumab. This trial enrolled 102 patients with a median age of 64 years. Treatment consisted of 6 cycles of PCR followed by alemtuzumab for either 4 or 18 weeks depending on the initial response to PCR. The overall response after PCR (complete remission, CR, nodular partial remission, nPR, and partial remission, PR) was 55%. Major responses (CR or nPR) were achieved in 6%. The median overall survival (OS) and the median progression-free survival were 28 and 12 months, respectively. The most serious nonlethal adverse events were myelosuppression, febrile neutropenia, fatigue, nausea, and hyponatremia. PCR is an effective and well-tolerated nucleoside-based regimen for heavily pretreated CLL patients with R/R disease. The addition of alemtuzumab to CLL patients with a minor response (PR) or stable disease did not result in a significant number of higher responses (CR or nPR) nor an improvement in OS.

Risk for malignancies of infectious etiology among adult survivors of specific non-Hodgkin lymphoma subtypes

Infectious agents have been identified in the etiology of certain non-Hodgkin lymphoma (NHL) subtypes and solid tumors. The impact of this shared etiology on risk for second cancers in NHL survivors has not been comprehensively studied. We used US population-based cancer registry data to quantify risk of solid malignancies associated with infectious etiology among 127 044 adult 1-year survivors of the 4 most common NHL subtypes diagnosed during 2000 to 2014 (mean follow-up, 4.5-5.2 years). Compared with the general population, elevated risks for liver, stomach, and anal cancers were observed among diffuse large B-cell lymphoma (DLBCL) survivors (standardized incidence ratio [SIR], 1.85; 95% confidence interval [CI], 1.46-2.31; SIR, 1.51; 95% CI, 1.16-1.94; SIR, 3.71; 95% CI, 2.52-5.27, respectively) and marginal zone lymphoma (MZL; SIR, 1.98; 95% CI, 1.34-2.83; SIR, 2.78; 95% CI, 2.02-3.74; SIR, 2.36; 95% CI, 1.02-4.64, respectively) but not follicular lymphoma or chronic lymphocytic leukemia/small lymphocytic lymphoma. Anal cancer risk was particularly elevated among DLBCL survivors with HIV (SIR, 68.34; 95% CI, 37.36-114.66) vs those without (SIR, 2.09; 95% CI, 1.22-3.34). The observed patterns are consistent with shared associations between these cancers and hepatitis C virus, Helicobacter pylori, and HIV, respectively. In contrast, risks for cervical and oropharyngeal/tonsil cancers were not elevated among survivors of any NHL subtype, possibly because of the lack of NHL association with human papillomavirus or population-wide screening practices (for cervical cancer). In summary, patterns of elevated second cancer risk differed by NHL subtype. Our results suggest shared infectious etiology has implications for subsequent cancer risks among DLBCL and MZL survivors, which may help inform surveillance for these survivors.

[Primary central nervous system lymphoma following immunotherapy for metastatic melanoma]

BACKGROUND

Anti-PD-1 and anti-CTLA-4 monoclonal antibodies are used in melanoma, while anti-PD-1 are also used in Hodgkin's lymphoma. Primary central nervous system lymphoma is a rare form of non-Hodgkin's lymphoma with few effective treatments. However, several recent studies have reported multiple cases of non-Hodgkin's lymphoma and primary central nervous system lymphoma treated by anti-PD-1 antibodies with favourable responses.

PATIENTS AND METHODS

This study focuses on the case of a 59-year-old man with metastatic melanoma treated by immunotherapy (anti-CTLA-4 followed by anti-PD-1). He underwent 28 courses of therapy with pembrolizumab. Treatment was stopped after clinical and radiological remission. The patient presented left hemiparesis and a primary central nervous system lymphoma was diagnosed two months after discontinuation of immunotherapy. He started urgent high-dose methotrexate chemotherapy but without significant results. Despite second-line chemotherapy with R-ICE (rituximab-ifosfamide, carboplatin and etoposide), the patient died.

DISCUSSION

Several hypotheses may be advanced regarding a possible relationship between immunotherapy and the occurrence of this primary central nervous system lymphoma. The lymphoma may have been pre-existing and controlled by immunotherapy, but progressing rapidly after treatment, or it may have been induced by the immunotherapy. However, immunotherapy may have played no role; the relationship between melanoma and lymphoma is well known.

CONCLUSION

While immunotherapy cannot be unequivocally incriminated in primary central nervous system lymphoma, this case raises many questions about the imputability of immunotherapy in the occurrence of secondary cancers, including lymphomas.

Second primary cancers in non-Hodgkin lymphoma: Family history and survival

Second primary cancers (SPCs) account for an increasing proportion of all cancer diagnoses and family history of cancer may be a risk factor for SPCs. Using the Swedish Family-Cancer Database on non-Hodgkin lymphoma (NHL), we assessed the influence of family history on risk of SPCs and of SPCs on survival. NHL patients were identified from the years 1958 to 2015 and generalized Poisson models were used to calculate relative risks (RRs) for SPCs and familial SPCs. Among 14,393 NHL patients, a total of 1,866 (13.0%) were diagnosed with SPC. Familial risk of nine particular cancers was associated with risks of these cancers as SPCs, with twofold to fivefold increase in RRs. At the end of a 25-year follow-up period, the survival probability for persons with SPC was only 20% of that for patients without SPC; the hazard ratio for SPC was 1.59 (95% CI: 1.46-1.72). Survival could be predicted by the prognostic groups based on first cancers and HRs increase systematically with worse prognosis yielding a trend of p = 4.6 × 10^-5 . SPCs had deleterious consequences for survival in NHL patients. Family history was associated with increasing numbers of SPCs. Prevention of SPCs and their early detection is an important target in the overall strategy to improve survival in NHL patients. Counseling for avoidance of risk factors and targeted screening based on family history are feasible steps in risk reduction.

Feline large-cell lymphoma following previous treatment for small-cell gastrointestinal lymphoma: incidence, clinical signs, clinicopathologic data, treatment of a secondary malignancy, response and survival

OBJECTIVES

Lymphoma is a common and clinically important malignancy in cats. Development of a second malignancy has been reported previously in 7-14% of cats with small-cell gastrointestinal (GI) lymphoma. The aim of our study was to describe the incidence, clinical signs, clinicopathologic data, response to therapy and outcomes in cats diagnosed with large-cell lymphoma following treatment for small-cell GI lymphoma.

METHODS

Medical records from a single referral specialty hospital were reviewed for all cats with lymphoma diagnosed between 2008 and 2017. The cases with a diagnosis of small-cell GI lymphoma followed by a diagnosis of any large-cell lymphoma and complete outcome data were selected for further review.

RESULTS

Seven hundred and forty cats with a diagnosis of lymphoma were identified. Twelve cats (12/121) treated for small-cell GI lymphoma followed by a diagnosis of any anatomic form of large cell lymphoma were identified. Nine cats met the study inclusion criteria and were used in analyses. Mean event-free survival time from small-cell GI lymphoma diagnosis until diagnosis of large-cell lymphoma was 543 days, with a median survival time of 615 days. Mean event-free survival time from large-cell lymphoma to death was 55 days, with a median survival time of 24.5 days. Hematocrit, albumin and total protein were significantly decreased when cats developed large-cell lymphoma compared with their values at the time of small-cell lymphoma diagnosis.

CONCLUSIONS AND RELEVANCE

Large-cell lymphoma occurred in 9.9% (12/121) of cats treated for small-cell GI lymphoma. Feline practitioners should include large-cell lymphoma on their list of differential diagnoses in cats diagnosed with small-cell GI lymphoma developing weight loss, anemia, hypoalbuminemia and hypoproteinemia.

Cause of Death in Follicular Lymphoma in the First Decade of the Rituximab Era: A Pooled Analysis of French and US Cohorts

PURPOSE

Although the life expectancy of patients with follicular lymphoma (FL) has increased, little is known of their causes of death (CODs) in the rituximab era.

PATIENTS AND METHODS

We pooled two cohorts of newly diagnosed patients with FL grade 1-3A. Patients were enrolled between 2001 and 2013 in two French referral institutions (N = 734; median follow-up 89 months) and 2002 and 2012 in the University of Iowa and Mayo Clinic Specialized Program of Research Excellence (SPORE; N = 920; median follow-up 84 months). COD was classified as being a result of lymphoma, other malignancy, treatment related, or all other causes.

RESULTS

Ten-year overall survival was comparable in the French (80%) and US (77%) cohorts. We were able to classify COD in 248 (88%) of 283 decedents. In the overall cohort, lymphoma was the most common COD, with a cumulative incidence of 10.3% at 10 years, followed by treatment-related mortality (3.0%), other malignancy (2.9%), other causes (2.2%), and unknown (3.0%). The 10-year cumulative incidence of death as a result of lymphoma or treatment was higher than death as a result of all other causes for each age group (including patients ≥ 70 years of age at diagnosis [25.4% v 16.6%]) Follicular Lymphoma International Prognostic Index score 3 to 5 (27.4% v 5.2%), but not Follicular Lymphoma International Prognostic Index score 0 to 1 (4.0% v 3.7%); for patients who failed to achieve event-free survival within 24 months from diagnosis (36.1% v 7.0%), but not for patients who achieved event-free survival within 24 months of diagnosis (6.7% v 5.7%); and for patients with a history of transformed FL (45.9% v 4.7%), but not among patients without (8.1% v 6.2%). Overall, 77 of 140 deaths as a result of lymphoma occurred in patients whose FL transformed after diagnosis.

CONCLUSION

Despite the improvement in overall survival in patients with FL in the rituximab era, their leading COD remains lymphoma, especially after disease transformation. Treatment-related mortality also represents a concern, which supports the need for less-toxic therapies.

Beyond maximum grade: modernising the assessment and reporting of adverse events in haematological malignancies

Tremendous progress in treatment and outcomes has been achieved across the whole range of haematological malignancies in the past two decades. Although cure rates for aggressive malignancies have increased, nowhere has progress been more impactful than in the management of typically incurable forms of haematological cancer. Population-based data have shown that 5-year survival for patients with chronic myelogenous and chronic lymphocytic leukaemia, indolent B-cell lymphomas, and multiple myeloma has improved markedly. This improvement is a result of substantial changes in disease management strategies in these malignancies. Several haematological malignancies are now chronic diseases that are treated with continuously administered therapies that have unique side-effects over time. In this Commission, an international panel of clinicians, clinical investigators, methodologists, regulators, and patient advocates representing a broad range of academic and clinical cancer expertise examine adverse events in haematological malignancies. The issues pertaining to assessment of adverse events examined here are relevant to a range of malignancies and have been, to date, underexplored in the context of haematology. The aim of this Commission is to improve toxicity assessment in clinical trials in haematological malignancies by critically examining the current process of adverse event assessment, highlighting the need to incorporate patient-reported outcomes, addressing issues unique to stem-cell transplantation and survivorship, appraising challenges in regulatory approval, and evaluating toxicity in real-world patients. We have identified a range of priority issues in these areas and defined potential solutions to challenges associated with adverse event assessment in the current treatment landscape of haematological malignancies.

Mutual Risks of Cutaneous Melanoma and Specific Lymphoid Neoplasms: Second Cancer Occurrence and Survival

Background

It is unclear whether the established association between cutaneous melanoma (CM) and lymphoid neoplasms (LNs) differs across LN subtypes. This study quantifies risk for developing CM after specific LNs and, conversely, for developing specific LNs after CM, as well as assessing clinical impact.

Methods

We identified a cohort of Caucasian adults (age 20-83 years) initially diagnosed with CM or LN, as reported to 17 US population-based cancer registries, 2000-2014. Standardized incidence ratios (SIRs) quantified second cancer risk. We assessed impact of second cancer development on risk of all-cause mortality using Cox regression.

Results

Among 151 949 one-or-more-year survivors of first primary LN, second primary CM risk was statistically significantly elevated after chronic lymphocytic leukemia/small lymphocytic lymphoma (SIR = 1.96, 95% confidence interval [CI] = 1.74 to 2.21), follicular lymphoma (SIR = 1.32, 95% CI = 1.09 to 1.58), and plasma cell neoplasms (SIR = 1.33, 95% CI = 1.07 to 1.63). Risks for these same subtypes were statistically significantly elevated among 148 336 survivors of first primary CM (SIR = 1.44, 95% CI = 1.25 to 1.66; SIR = 1.47, 95% CI = 1.21 to 1.77; SIR = 1.25, 95% CI = 1.06 to 1.47; respectively). Risk for CM was statistically significantly elevated after diffuse large B-cell lymphoma (SIR = 1.22, 95% CI = 1.02 to 1.45) and Hodgkin lymphoma (SIR = 1.75, 95% CI = 1.33 to 2.26), but the reciprocal relationship was not observed. There were no statistically significant associations between marginal zone lymphoma and CM. Among survivors of most LN subtypes, CM statistically significantly increased risk of death (hazard ratio [HR] range = 1.52, 95% CI = 1.25 to 1.85, to 2.46, 95% CI = 1.45 to 4.16). Among survivors of CM, LN statistically significantly increased risk of death (HR range = 1.75, 95% CI = 1.15 to 2.65, to 6.28, 95% CI = 5.00 to 7.88), with the highest risks observed for the most aggressive LN subtypes.

Conclusions

Heterogeneous associations between CM and specific LN subtypes provide novel insights into the etiology of these malignancies, with the mutual association between CM and certain LN suggesting shared etiology. Development of second primary CM or LN substantially reduces overall survival.

Secondary mixed phenotype acute leukemia following chemotherapy for diffuse large B-cell lymphoma: a case report and review of the literature

Therapy-related mixed phenotype acute leukemia (MPAL) following non-Hodgkin's lymphoma (NHL) is extremely rare. We present here the case of an elderly man, diagnosed with diffuse large B-cell lymphoma (DLBCL) through a tonsil biopsy. After treatment with seven cycles of CHOP (cyclophosphamide, doxorubicin, vincristine and prednisolone) like regimen, the patient developed to MPAL (B/myeloid) with del(7)(q22), t(6;9)(p23;q34), DEK/NUP214 fusion, as well as EZH2 and TET2 mutations. The patient was successively treated with chemotherapy and allogenetic hematopoietic stem cell transplantation. Until recently he is still alive more than 23 months without relapse.

Therapy-related acute myeloid leukemia following treatment of lymphoid malignancies

Therapy-related acute myeloid leukemia (t-AML) is a heterogeneous entity most frequently related to breast cancer or lymphoproliferative diseases (LD). Population-based studies have reported an increased risk of t-AML after treatment of lymphomas. The aim of this study was to describe the characteristics and outcome of 80 consecutive cases of t-AML following treatment of LD. t-AML accounted for 2.3% of all AML cases, occurred 60 months after LD diagnosis, and were characterized by a high frequency of FAB M6 AML and poor-risk cytogenetic abnormalities. Time to t-AML diagnosis was influenced by patient age, type of LD, and treatment. Among the 48 t-AML patients treated with intensive chemotherapy, median overall survival (OS) was 7.7 months compared to 26.1 months in de novo, 4.2 months in post-myeloproliferative neoplasm, 9.4 months in post-myelodysplastic syndrome, 8.6 months in post-chronic myelomonocytic leukemia AML, 13.4 months in t-AML secondary to the treatment of solid cancer, and 14.7 months in breast cancer only. OS of post-LD t-AML patients was significantly influenced by age, performance status, myelodysplastic syndrome prior to LD/t-AML, and treatment regimen for LD. Thus, t-AML following lymphoid malignancies treatment should be considered as very high-risk secondary AML. New treatment strategies in patients with LD/t-AML are needed urgently.

Subsequent primary malignancies after diffuse large B-cell lymphoma in the modern treatment era

With the addition of rituximab and other treatment advances, survival after diffuse large B-cell lymphoma (DLBCL) has improved, but subsequent primary malignancies (SPMs) have emerged as an important challenge for DLBCL survivorship. We calculated standardized incidence ratios (SIRs) and 95% confidence intervals (CIs) for SPMs among 23 879 patients who survived at least 1 year after a first primary DLBCL diagnosed during 1989-2012, compared to the general population in California. Cumulative incidence (CMI) of SPMs, accounting for the competing risk of death, also was calculated. We found that the incidence of acute myeloid leukaemia (AML) nearly doubled in the post-rituximab era [SIR (95% CI) 4·39 (2·51-7·13) pre- (1989-2000) and 8·70 (6·62-11·22) post-rituximab (2001-2012)]. Subsequent thyroid cancer was rare pre-rituximab, but increased substantially after 2001 [0·66 (0·08-2·37) vs. 2·27(1·44-3·41)]. The 5-year CMI for all SPMs (4·77% pre- vs. 5·41% post-rituximab, P = 0·047), AML (0·15% vs. 0·41%, P = 0·003), thyroid cancer (0·03% vs. 0·15%, P = 0·003) and melanoma (0·25% vs. 0·42%, P = 0·020) were greater in DLBCL patients diagnosed in the post- versus pre-rituximab period. This study provides insight into the changing pattern of SPM occurrence after the introduction of rituximab, which may elucidate the aetiology of SPMs and should guide future cancer surveillance efforts among DLBCL patients.

Risk of Second Primary Malignancies in Patients With Follicular Lymphoma: A United States Population-based Study

BACKGROUND

With the improving outcomes of patients with follicular lymphoma (FL), it is imperative to focus on survivorship issues, including the development of second primary malignancies (SPMs). We used a large US database to measure the risk of SPMs among FL survivors.

MATERIALS AND METHODS

We used the Surveillance, Epidemiology, and End Results-13 registry to identify FL patients from 1992 to 2011. We calculated the risk of SPMs, developing ≥ 6 months after diagnosis, using the standardized incidence ratio (SIR) and absolute excess risk. We calculated the cumulative incidence of SPMs using the competing risk method and risk factors for SPMs using univariate and multivariate methods.

RESULTS

Of a total of 15,517 patients with FL followed up for a median of 71 months, 1540 (9.9%) developed SPMs, with a SIR of 1.08 and absolute excess risk of 11.3 per 10,000 person-years. A significantly increased risk was noted for Hodgkin lymphoma (SIR, 5.85), acute myeloid leukemia (SIR, 4.88), and the following sites: oral cavity and pharynx (SIR, 1.43), stomach (SIR, 1.43), lung and bronchus (SIR, 1.35), melanoma of skin (SIR, 1.38), other nonepithelial cancers of the skin (SIR, 2.88), urinary bladder (SIR, 1.24), and kidney/renal pelvis (SIR, 1.43). The cumulative incidence of SPMs was 11.06% at 10 years. Multivariate regression showed that age > 65 years (SIR, 1.57; P < .001), male gender (SIR, 1.43; P < .001), and receipt of radiation (SIR, 1.24; P = .001) predicted a higher rate of SPMs.

CONCLUSION

Patients with FL have increased risk of both hematologic and solid malignancies. Risk factors for SPMs include advanced age, male gender, and receipt of radiation therapy.

A protocol for prospective studies of 25-hydroxyvitamin D, leptin and body mass index in relation to cutaneous melanoma incidence and survival

INTRODUCTION

The incidence and mortality rates of cutaneous melanoma (CM) are increasing among fair-skinned populations worldwide. Ultraviolet radiation (UVR) is the principal risk factor for CM, but is also the main source of 25-hydroxyvitamin D (25(OH)D), which has been associated with reduced risk and better prognosis of some cancer types. However, both low and high 25(OH)D levels have been associated with increased risk of CM. Obesity as measured by body mass index (BMI) is associated with risk of several cancers and has also been suggested as a risk factor for CM, and may also be related to insufficient 25(OH)D and/or high leptin levels. Moreover, contracting a CM diagnosis has been associated with increased risk of developing second cancer. We aim to study whether low prediagnostic serum levels of 25(OH)D, high prediagnostic levels of BMI and high serum leptin levels influence CM incidence, Breslow thickness and CM mortality, and risk of second cancer and survival after a CM diagnosis.

METHODS AND ANALYSIS

Cohort and nested case-control studies will be carried out using the population-based Janus Serum Bank Cohort (archival prediagnostic sera, BMI, smoking and physical activity), with follow-up from 1972 to 2014. Additional data will be received from the Cancer Registry of Norway, the national Cause of Death Registry, Statistics Norway (education and occupation) and exposure matrices of UVR. Time-to-event regression models will be used to analyse the cohort data, while the nested case-control studies will be analysed by conditional logistic regression. A multilevel approach will be applied when incorporating group-level data.

ETHICS AND DISSEMINATION

The project is approved by the Regional Committee for Medical Research Ethics and is funded by the Norwegian Cancer Society. Results will be published in peer-reviewed journals, at scientific conferences and in the news media.

High ten-year remission rates following rituximab, fludarabine, mitoxantrone and dexamethasone (R-FND) with interferon maintenance in indolent lymphoma: Results of a randomized Study

We report a single-centre, randomized study evaluating the efficacy and safety of concurrent fludarabine, mitoxantrone, dexamethasone (FND) and rituximab versus sequential FND followed by rituximab in 158 patients with advanced stage, previously untreated indolent lymphoma, enrolled between 1997 and 2002. Patients were randomized to 6-8 cycles of FND followed by 6 monthly doses of rituximab or 6 doses of rituximab given concurrently with FND. All patients who achieved at least a partial response received 12 months of interferon (IFN) maintenance. Median ages were 54 and 55 years. The two groups were comparable with the exception of a higher percentage of females (65% vs. 43%) and baseline anaemia (23% vs. 11%) in the FND followed by rituximab group. Complete response/unconfirmed complete response rates were 89% and 93%. The most frequent grade ≥ 3 toxicity was neutropenia (86% vs. 96%). Neutropenic fever occurred in 21% and 16%. Late toxicity included myelodysplastic syndrome (n = 3) and acute myeloid leukaemia (n = 5). With 12·5 years of follow-up, no significant differences based on treatment schedule were observed. 10-year overall survival estimates were 76% and 73%. 10-year progression-free survival estimates were 52% and 51%. FND with concurrent or sequential rituximab, and IFN maintenance in indolent lymphoma demonstrated high response rates and robust survival.

Long-Term Incidence of Secondary Malignancies after Allogeneic Hematopoietic Cell Transplantation: A Single-Center Experience

To review the emergence of secondary malignancies (SMs) in recipients of allogeneic hematopoietic cell transplantation (HCT), we documented the occurrence of SMs in 2415 allogeneic HCT recipients, ages 18 to 71, in a single center over 4 decades. SMs were seen in 209 patients, including 58 with nonmetastatic squamous cell (SCC) and basal cell carcinoma (BCC) of the skin. Cumulative incidence of SM was 6.3% at 10 years, 13.5% at 20 years, and 17.6% at 30 years post-HCT. Median age at diagnosis of SMs was 61 years (range, 21 to 85). By multivariable analysis, older age at HCT was the only independent prognostic factor for SM (HR, 1.39 for ages 41 to 55 and HR, 1.92 for age > 55 compared with age ≤ 40; P = .001). The rate of SM (excluding nonmetastatic SCC/BCC of skin) after HCT was 2.07 times higher (P = .01) compared with the general population. Overall survival (OS) after diagnosis of SM (excluding nonmetastatic SCC/BCC of skin) was 58% at 5 years and 50% at 10 years postdiagnosis. Eastern Cooperative Oncology Group (ECOG) score was the only independent predictor of OS on multivariable analysis, with over 2-fold increased risk of death for patients with an ECOG score of 1 and over 6-fold for ECOG scores of 2 to 4, compared with ECOG score 0 (P < .0001). Forty of 209 patients (19%) diagnosed with SMs subsequently developed another new malignancy. OS was 68% and 51% at 5 and 10 years, respectively. The survival of SM patients post-HCT is favorable, thus warranting diligent long-term cancer screening and standard of care treatment. ECOG status of these patients is a predominant prognostic factor.

Second cancer incidence in primary mediastinal B-cell lymphoma treated with methotrexate with leucovorin rescue, doxorubicin, cyclophosphamide, vincristine, prednisone, and bleomycin regimen with or without rituximab and mediastinal radiotherapy: Results from a monoinstitutional cohort analysis of long-term survivors

Our aim is to assess the incidence of second cancer in long-time surviving primary mediastinal B-cell lymphoma (PMBCL) patients treated with combined radiochemoimmunotherapy (standard methotrexate with leucovorin rescue, doxorubicin, cyclophosphamide, vincristine, prednisone, and bleomycin with rituximab and mediastinal radiation therapy at a dose of 30 to 36 Gy). For this purpose, 92 points were evaluated. After a median overall survival of 137 months (range 76-212), we recorded second cancer in 3 of 80 long-surviving patients (3.75%) with cumulative incidence of 3.47% at 15 years and 11% at 17 years, with a 17-year second cancer-free survival of 82%. We observed 2 papillary thyroid cancers with a standardized incidence ratio (SIR) of 7.97 and an absolute excess risk (AER) of 17. 84 and 1 acute myeloid leukemia (AML) with an SIR of 66.53 and an AER of 10.05. No breast cancer occurred. Although we should take into account the limits of the proposed statistical analysis, combined modality treatment was related to a significant SIR and AER for thyroid cancer and acute myeloid leukemia.

The Importance of an In-depth Study of Immunoglobulin Gene Rearrangements When Ascertaining the Clonal Relationship between Concomitant Chronic Lymphocytic Leukemia and Multiple Myeloma

Chronic lymphocytic leukemia (CLL) and multiple myeloma (MM) are hematological disorders that occur at different stages of B-cell development. It has been shown that CLL B-cells can differentiate into plasma cells in vitro and in vivo. CLL is the most frequent adult leukemia in the western world. It is a heterogeneous disease, characterized by clonal proliferation and the accumulation of mature CD5+ B lymphocytes (1). MM is a clonal plasma cell malignancy that accounts for more than 10% of all hematologic cancers (2). Although secondary cancers [particularly solid tumors (3-5)] can occur with CLL and MM, the concomitant occurrence of these two disorders in the same patient is rare [for a review of the few reported cases, see Ref. (6)]. The clonal relationship between these diseases has not always been clarified but is important in terms of understanding the pathogenesis and optimizing treatment. The clonal relationship between CLL and MM can be evaluated by (i) analyzing immunoglobulin (Ig) heavy chain and light chain (Ig kappa light chain and Ig lambda light chain) gene rearrangement, (ii) identifying and comparing somatic mutations, and (iii) studying chromosomic aberrations. Nevertheless, Ig rearrangements must always be interpreted in the light of specific phenomena such as allelic exclusion, B-cell receptor (BCR) revision (V_H and D_H gene replacement), BCR editing, and somatic mutations-events that were not considered in previous studies. These issues can be addressed by sequencing the rearranged Ig genes from sorted populations and interpreting the generated data. In the present study, we evaluated the putative clonal relationship between the two diseases by combining DNA copy number analysis with an assessment of Ig gene rearrangements [clonality assessment, V(D)J sequencing, and somatic hypermutation analysis] in highly enriched CD19+ CD5+ (CLL) and CD38+ CD138+ (MM) cell populations. Array comparative genomic hybridization data suggested a possible phylogenic progression from CLL to MM. Moreover, V(D)J sequencing indicated that both CLL and MM cells used the same V_H and J_H genes but different D_H genes. However, in-depth analysis and interpretation of Ig gene rearrangements ultimately suggested that the two diseases had distinct clonal origins.

[Sarcoma developed in irradiated area: Preliminary results of the SARI trial]

Radiotherapy and surgery are the two main pillars of the locoregional treatment of cancer. The risk of second malignancy is better evaluated and constitutes a major issue regarding radioprotection of the patients. Among malignant disease observed in the surviving irradiated patients, the occurrence of sarcoma is a rare event but associated with a poor outcome since the 5 year overall survival is estimated at 10 to 35 %. The SARI protocol, written in 2011, included 120 patients and 240 controlled patients, irradiated in the same conditions but without sarcoma observed during the follow up. The main objective was to identify the clinical and biological factors associated with the occurrence of such a complication. The secondary objective was to identify the dosimetric characteristics of the treatment of the primary. Preliminary results will be presented during the 2016 meeting of the French radiation oncology society.

Radioimmunotherapy for non-Hodgkin's lymphoma; positioning, safety, and efficacy of 90Y-Ibritumomab. 10 years of experience and follow-up

INTRODUCTION

Radioimmunotherapy (RIT) is one of the therapies directed against molecular targets in non-Hodgkin's lymphoma (NHL).

OBJECTIVE

To evaluate the positioning, safety, and effectiveness of RIT with 90Y-Ibritumomab in NHL patients.

METHOD

A retrospective study was conducted on patients with NHL who received RIT with 90Y-Ibritumomab. An evaluation was made of the concordance with clinical guidelines, toxicity as rated by the Common Terminology Criteria for Adverse Events (CTCAE), and effectiveness was assessed based on response to treatment, overall survival (OS), and progression-free survival (PFS).

RESULTS

RIT was requested in 26 patients, of whom 21 (11 women, mean age 56±10 years) were included in the study, with the following distribution: Follicular NHL, 67%, Mantle NHL, 14%, Diffuse large B-cell NHL, 9.5%, and Transformed NHL 9.5%. Twelve patients with refractory NHL, 7 for consolidation response, and 2 transplant conditioning, were treated. Adverse effects were observed in 71% of patients, which were usually manageable and transient, and with the most common being thrombocytopenia. At 3-4 months, overall response rate was 76.2% (71.4% complete and 4.8% partial response), and 19% had progression of disease. With a median follow up of 70 months, the OS was 96±8 months, and the PFS was 54±11 months.

CONCLUSION

RIT showed a moderate correlation with clinical guidelines, and is probably underused. Adverse effects were common, mild, and manageable. The data show a high complete response rate and an increase in the OS and PFS.

The role of autologous and allogeneic stem cell transplantation in the management of indolent B-cell lymphoma

Despite improvements over the past decade in the overall survival of patients with indolent non-Hodgkin lymphomas, these lymphomas remain largely incurable with standard therapies. Immunochemotherapy with rituximab-based regimens has become a well-established standard of care in the primary and relapsed disease settings. The role of hematopoietic stem cell transplantation in indolent lymphoma has been defined by the adoption of this therapy largely in the relapse setting because randomized trials in the first-line setting have not shown survival advantages. Allogeneic stem cell transplantation has the possibility for cure because of the potential for immunologic graft-versus-lymphoma effect, but there are significant concerns regarding nonrelapse mortality. Autologous stem cell transplantation offers a safe treatment platform, but relapse remains a significant issue. The role of transplantation in the current treatment landscape of immunochemotherapy has not been conclusively proven, and randomized trials are lacking. This review summarizes the current relevant data regarding transplantation in indolent non-Hodgkin lymphoma and highlights the issues relevant to clinicians in the field.

Incidence and prognostic impact of other cancers in a population of long-term survivors of chronic lymphocytic leukemia

BACKGROUND

Information on the impact of other cancers (OCs) in long-term survivors (LTSs) of chronic lymphocytic leukemia (CLL) is limited.

PATIENTS AND METHODS

Patients with CLL who survived >10 years were defined as LTSs of CLL. We calculated standardized incidence ratios (SIRs) to compare the incidence of OC in LTS of CLL versus the general population. A multivariable model was used to identify independent predictors of OC. Overall survival was analyzed as a function of the presence of OC.

RESULTS

Among 797 LTSs of CLL, the cumulative frequency of OC was 36%, similar between 570 patients (72%) who required treatment for CLL (TRT) and 227 (28%) who remained untreated (UT). The most common OC in both groups was non-melanoma skin cancer, followed by prostate cancer, breast cancer, melanoma, lung cancer, and leukemia in TRT patients, and by prostate cancer, breast cancer, melanoma, lung cancer, and gastrointestinal tumors in the UT group. The SIR for all OC was 1.2 (P = 0.034). It was higher in males (SIR 1.31; P = 0.013) and patients <60 years (SIR 1.27; P = 0.027). A higher SIR was shown for secondary leukemia, melanoma, and head-and-neck cancers, whereas a lower SIR was found for gastrointestinal and bladder cancers. Independent predictors of OC development were advanced age, male gender, and lower platelets. The survival of patients with OC was 16.2 months and that of patients without OC 22.9 years.

CONCLUSIONS

LTSs of CLL have an increased incidence of OC compared with the general population. CLL therapy is not a risk factor for OC in LTSs of CLL. The presence of an OC in these patients may be associated with shorter survival.

Risk of non-hematologic cancer in individuals with high-count monoclonal B-cell lymphocytosis

It is unknown whether individuals with monoclonal B-cell lymphocytosis (MBL) are at risk for adverse outcomes associated with chronic lymphocytic leukemia (CLL), such as the risk of non-hematologic cancer. We identified all locally residing individuals diagnosed with high-count MBL at Mayo Clinic between 1999 and 2009 and compared their rates of non-hematologic cancer with that of patients with CLL and two control cohorts: general medicine patients and patients who underwent clinical evaluation with flow cytometry but who had no hematologic malignancy. After excluding individuals with prior cancers, there were 107 high-count MBL cases, 132 CLL cases, 589 clinic controls and 482 flow cytometry controls. With 4.6 years median follow-up, 14 (13%) individuals with high-count MBL, 21 (4%) clinic controls (comparison MBL P<0.0001), 18 (4%) flow controls (comparison MBL P=0.0001) and 16 (12%) CLL patients (comparison MBL P=0.82) developed non-hematologic cancer. On multivariable Cox regression analysis, individuals with high-count MBL had higher risk of non-hematologic cancer compared with flow controls (hazard ratio (HR)=2.36; P=0.04) and borderline higher risk compared with clinic controls (HR=2.00; P=0.07). Patients with high-count MBL appear to be at increased risk for non-hematologic cancer, further reinforcing that high-count MBL has a distinct clinical phenotype despite low risk of progression to CLL.

Safety and efficacy of radioimmunotherapy (RIT) in treatment of non-Hodgkin's lymphoma in the community setting

INTRODUCTION

Radioimmunotherapy (RIT) is a unique therapeutic modality that combines biologic and radiolytic mechanisms to induce tumor kill. RIT is underutilized in the community outpatient setting.

METHODS

This is an institutional review of patients treated with RIT at St. John Hospital and Medical Center (SJH&MC) 2003-2011. RIT agents were dosed according to recommended guidelines. Response was assessed using the Revised Response Criteria for Malignant Lymphoma and toxicity was assessed using the National Cancer Institute Common Terminology Criteria for Adverse Events. The primary aim was to assess overall response rate (ORR) and overall survival (OS). The secondary aim was to assess the impact of variable host and disease factors on the ORR to RIT and OS.

RESULTS

Forty-eight patients were treated with RIT within the specified period at SJH&MC; of which 52% with follicular lymphoma (FL) and 46% with diffuse large B cell lymphoma (DLBCL). The majority of patients had relapsed or refractory disease (98%). Median duration of follow-up was 17 months. The ORR was 73% with 44% complete remission (CR) rate and OS of 48 months. The ORR was 79% with 58% CR rate and OS of 82 months among FL patients. Among DLBCL patients, the ORR was 65% with 30% CR rate and OS of 39 months. Response to last therapy before RIT was the only significant predictor of response to RIT and a significant predictor of OS in multivariate analyses. Prior exposure to EBRT did not predict response or survival in multivariate analyses. Toxicity was manageable and predominantly hematologic.

CONCLUSIONS

RIT is effective and feasible for use in the community outpatient setting.

ADVANCES IN KNOWLEDGE AND IMPLICATIONS FOR PATIENT CARE

Patients with B-cell NHL can safely receive RIT close to home. With some coordination of effort, it is not difficult for community-based cancer centers to implement this treatment modality.

Risk Factors for Melanoma Among Survivors of Non-Hodgkin Lymphoma

PURPOSE

Previous studies have reported that survivors of non-Hodgkin lymphoma (NHL) have an increased risk of developing cutaneous melanoma; however, risks associated with specific treatments and immune-related risk factors have not been quantified.

PATIENTS AND METHODS

We evaluated second melanoma risk among 44,870 1-year survivors of first primary NHL diagnosed at age 66 to 83 years from 1992 to 2009 and included in the Surveillance, Epidemiology, and End Results-Medicare database. Information on NHL treatments, autoimmune diseases, and infections was derived from Medicare claims.

RESULTS

A total of 202 second melanoma cases occurred among survivors of NHL, including 91 after chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL) and 111 after other NHL subtypes (cumulative incidence by age 85 years: CLL/SLL, 1.37%; other NHL subtypes, 0.78%). Melanoma risk after CLL/SLL was significantly increased among patients who received infused fludarabine-containing chemotherapy with or without rituximab (n=18: hazard ratio [HR], 1.92; 95% CI, 1.09 to 3.40; n=10: HR, 2.92; 95% CI, 1.42 to 6.01, respectively). Significantly elevated risks also were associated with T-cell activating autoimmune diseases diagnosed before CLL/SLL (n=36: HR, 2.27; 95% CI, 1.34 to 3.84) or after CLL/SLL (n=49: HR, 2.92; 95% CI, 1.66 to 5.12). In contrast, among patients with other NHL subtypes, melanoma risk was not associated with specific treatments or with T-cell/B-cell immune conditions. Generally, infections were not associated with melanoma risk, except for urinary tract infections (CLL/SLL), localized scleroderma, pneumonia, and gastrohepatic infections (other NHLs).

CONCLUSION

Our findings suggest immune perturbation may contribute to the development of melanoma after CLL/SLL. Increased vigilance is warranted among survivors of NHL to maximize opportunities for early detection of melanoma.

Screening for Anal Cancer in Women

OBJECTIVE

The incidence of anal cancer is higher in women than men in the general population and has been increasing for several decades. Similar to cervical cancer, most anal cancers are associated with human papillomavirus (HPV), and it is believed that anal cancers are preceded by anal high-grade squamous intraepithelial lesions (HSIL). Our goals were to summarize the literature on anal cancer, HSIL, and HPV infection in women and to provide screening recommendations in women.

METHODS

A group of experts convened by the American Society for Colposcopy and Cervical Pathology and the International Anal Neoplasia Society reviewed the literature on anal HPV infection, anal SIL, and anal cancer in women.

RESULTS

Anal HPV infection is common in women but is relatively transient in most. The risk of anal HSIL and cancer varies considerably by risk group, with human immunodeficiency virus-infected women and those with a history of lower genital tract neoplasia at highest risk compared with the general population.

CONCLUSIONS

While there are no data yet to demonstrate that identification and treatment of anal HSIL leads to reduced risk of anal cancer, women in groups at the highest risk should be queried for anal cancer symptoms and required to have digital anorectal examinations to detect anal cancers. Human immunodeficiency virus-infected women and women with lower genital tract neoplasia may be considered for screening with anal cytology with triage to treatment if HSIL is diagnosed. Healthy women with no known risk factors or anal cancer symptoms do not need to be routinely screened for anal cancer or anal HSIL.

Restoration of the Dentition in a Patient with a History of Non-Hodgkin Lymphoma and Gastroesophageal Reflux Disease

Patients are concerned about dental disease and their appearance. Clinicians often must decide not only the type of restoration, but also the type of material for restoration that will provide aesthetics and longevity. A modern practitioner should know the pros and cons of different types of crowns and veneers. They are also responsible to provide treatment for patients with complicated medical histories. Risk assessments include current conditions, risks of recurrence, and suggestions for maintenance of restorations, as well as guidelines to promote the future health and well-being of the patient.

Development of second primary malignancy in patients with non-Hodgkin lymphoma: a nationwide population-based study

BACKGROUND

With the improved survival of non-Hodgkin lymphoma (NHL) patients, development of second primary malignancy (SPM) has become an increasingly important issue in these long-term survivors.

METHODS

We conducted a retrospective study to analyze NHL patients diagnosed between January 1997 and December 2010 in Taiwan. Standardized incidence ratios (SIRs) were applied to compare the risk of SPMs in NHL patients and the general population. Multivariate analysis was performed to determine the independent predictors of SPM.

RESULT

NHL patients have a significantly greater risk of developing SPM [SIR 1.43; 95 % confidence interval (CI) 1.32-1.55; p < 0.001). A significantly high SIR was noted for leukemia, myeloma, and neoplasms of the bone and soft tissue, thyroid, central nervous system, skin, stomach, head and neck, liver and biliary tract, and the lungs and mediastinum. Multivariate analysis revealed that age ≥60 years [hazard ratios (HR) 2.04], being male (HR 1.22), comorbidities of chronic obstructive pulmonary disease (HR 1.34), liver cirrhosis (HR 1.50), hepatitis C infection (HR 1.94) and therapy containing radiotherapy (HR 1.38) were the significant predictors for SPM occurrence. The median follow-up time and survival time were 3.37 and 9.45 years, respectively.

CONCLUSION

This Taiwanese population-based study provides updated data about the risk of SPM in NHL patients, demonstrating an approximately 1.5 time greater risk of SPM compared to the general population. A high risk of SPM for myeloma and hepatocellular carcinoma is unique to Asian patients.

Differential diagnosis problems in a patient with dysphonia and chronic lymphocytic leukemia

Dysphonia is frequently an expression of laryngitis, especially when it comes in the evolution of an immunosuppressed patient, as happens in chronic lymphoproliferation. But other causes of dysphonia should also not be forgotten, including the possibility of new malignancies, especially due to the fact that these patients have genomic instability that predisposes to appearance of a second or even a third cancer. We present the case of a patient who developed dysphonia during chronic lymphocytic leukemia evolution. Its etiology was a mediastinal compression through lymph nodes, not linked to leukemia, but produced by metastases of a bronchopulmonary cancer, appeared recently. Dysphonia condition due to vocal cord dysfunction must include diseases of the mediastinum, the neck and the brain stem. The rapid and correct diagnosis and the prompt start of an appropriate treatment are of paramount importance for clinician who manage their care and for patient survival.

Survival analysis in hematologic malignancies: recommendations for clinicians

The widespread availability of statistical packages has undoubtedly helped hematologists worldwide in the analysis of their data, but has also led to the inappropriate use of statistical methods. In this article, we review some basic concepts of survival analysis and also make recommendations about how and when to perform each particular test using SPSS, Stata and R. In particular, we describe a simple way of defining cut-off points for continuous variables and the appropriate and inappropriate uses of the Kaplan-Meier method and Cox proportional hazard regression models. We also provide practical advice on how to check the proportional hazards assumption and briefly review the role of relative survival and multiple imputation.