Clinical, molecular, and environmental risk factors for hodgkin lymphoma

Role of non-chromosomal birth defects on the risk of developing childhood Hodgkin lymphoma: A Children's Oncology Group study

BACKGROUND

Non-chromosomal birth defects are an important risk factor for several childhood cancers. However, these associations are less clear for Hodgkin lymphoma (HL). Therefore, we sought to more fully elucidate the association between non-chromosomal birth defects and HL risk.

PROCEDURE

Information on cases (n = 517) diagnosed with HL (ages of 0-14) at Children's Oncology Group Institutions for the period of 1989-2003 was obtained. Control children without a history of cancer (n = 784) were identified using random digit dialing and individually matched to cases on sex, race/ethnicity, age, and geographic location. Parents completed comprehensive interviews and answered questions including whether their child had been born with a non-chromosomal birth defect. To test the association between birth defects and HL risk, conditional logistic regression was applied to generate adjusted odds ratios (aORs) and 95% confidence intervals (CIs).

RESULTS

Children born with any non-chromosomal birth defect were not more likely to be diagnosed with HL at 0-14 years of age (aOR: 0.91; 95% CI: 0.69-1.21). No associations were detected between major or minor birth defects and HL (aOR: 1.34; 95% CI: 0.67-2.67 and aOR: 0.88; 95% CI: 0.57-1.34, respectively). Similarly, no association was observed for children born with any birth defect and EBV-positive HL (aOR: 0.57; 95% CI: 0.25-1.26).

CONCLUSIONS

Previous assessments of HL in children with non-chromosomal birth defects have been limited. Using data from the largest case-control study of HL in those <15 years of age, we did not observe strong associations between being born with a birth defect and HL risk.

Cancer status in the Occupied Palestinian Territories: types; incidence; mortality; sex, age, and geography distribution; and possible causes

Cancer is a disease in which some cells of the body grow uncontrollably and occasionally spread to other parts of the body. With a group of more than 100 different types, cancer can start almost anywhere in the body. Defective cells may form a mass called a tumor which can be cancerous (malignant), which grows and spreads to other parts of the body, or benign that can grow but not spread throughout the body. In 2021, more than 10 million people died of cancer worldwide (1 out of 6 deaths). This paper has thoroughly investigated the cancer status in the Occupied Palestinian Territories (OPT), in terms of its various types; incidence; mortality; sex, age, and geography distribution; and potential causes. In the OPT, with a population of 5.35 million, cancer mortality was 14% in 2016, being the second cause of death after cardiovascular diseases accounting 30.6% of all causes of death. Cancer mortality in the OPT increased by 136% from 2000 to 2016, and by 14% from 2016 to 2020. In addition to other types of cancer in the OPT, its main types are lung (highest in males), breast (highest in females), colorectal (highest in both sexes), and leukemia (highest in children). The high rates of different types of cancer in the OPT can be attributed to various causes, including those related to environmental pollution, nutrition, stress, and lifestyle factors (smoking, lack of activity, increased dependence on technologies, etc.), whereas only 10-30% of cancer cases are attributed to genetics.

Classical Hodgkin Lymphoma: From Past to Future-A Comprehensive Review of Pathophysiology and Therapeutic Advances

Hodgkin lymphoma, a hematological malignancy of lymphoid origin that typically arises from germinal-center B cells, has an excellent overall prognosis. However, the treatment of patients who relapse or develop resistant disease still poses a substantial clinical and research challenge, even though current risk-adapted and response-based treatment techniques produce overall survival rates of over 95%. The appearance of late malignancies after the successful cure of primary or relapsed disease continues to be a major concern, mostly because of high survival rates. Particularly in pediatric HL patients, the chance of developing secondary leukemia is manifold compared to that in the general pediatric population, and the prognosis for patients with secondary leukemia is much worse than that for patients with other hematological malignancies. Therefore, it is crucial to develop clinically useful biomarkers to stratify patients according to their risk of late malignancies and determine which require intense treatment regimens to maintain the ideal balance between maximizing survival rates and avoiding late consequences. In this article, we review HL's epidemiology, risk factors, staging, molecular and genetic biomarkers, and treatments for children and adults, as well as treatment-related adverse events and the late development of secondary malignancies in patients with the disease.

Spatiotemporal variations in childhood lymphoma cancer incidence and its survival rate in Iran, 2005-2015: a cross-sectional study

BACKGROUND

Childhood lymphoma is the second leading cause of cancer in children under 15 years of age in Iran. The aim of this study was to investigate the spatial and time variations in lymphoma incidence as well as the children's survival time in Iran.

METHOD

This cross-sectional study was conducted using lymphoma cases (children under 14 years of age) from 2005 to 2015, and the data were obtained from the National Cancer Registry Center. The frequency, age-standardised incidence rate (ASIR), spatial clustering in national level and the survival rate (1 year and 5 years) using Kaplan-Meier method were evaluated. We used Spatial and Temporal Scan statistics software in order to detect statistically significant clusters in spatial analysis.

RESULTS

A total number of 746 girls and 1610 boys were diagnosed with lymphoma during a 10-year period. ASIRs (per 100 000 people) for girls ranged from 0 in Ilam to 3.47 in Yasuj, and it ranged from 0.19 in Ilam to 5.91 in Yazd for boys from 2005 to 2015. Spatial analysis result showed a large statistically significant cluster (the most likely cluster) for both boys (relative risk (RR)=2.37) and girls (RR=2.49) located in the northwest of Iran. Fortunately, survival rate for both boys and girls was over 95.5%.

CONCLUSION

Lymphoma incidence rates had heterogeneous geographical distribution, and some significant clusters were identified which strengthens the role of possible aetiological factors, and further studies are needed to clarify this ambiguity. Fortunately, the survival rate of this cancer in Iran was good and it was similar to the high-income countries.

Bimodal Age Distribution in Cancer Incidence

Cancer is caused by accumulation of genetic changes which include activation of protooncogenes and loss of tumor suppressor genes. The age-specific incidence of cancer in general increases with advancing age. However, some cancers exhibit a bimodal distribution. Commonly recognized cancers with bimodal age distribution include acute lymphoblastic leukemia, osteosarcoma, Hodgkin's lymphoma, germ cell tumors and breast cancer. Delayed infection hypothesis has been used to provide explanation for the early childhood peak in leukemias and lymphomas, whereas the peak at an older age is associated with accumulation of protooncogenes and weakened immune system. Further genetic analysis and histopathological variations point to distinctly different cancers, varying genetically and histologically, which are often combined under a single category of cancers. Tumor characteristics and age distribution of these cancers varies also by population groups and has further implications on cancer screening methods. Although significant advances have been made to explain the bimodal nature of such cancers, the specific genetic mechanisms for each age distribution remain to be elucidated. Further distinction among the different cancer subtypes may lead to improvements in individual risk assessments, prevention and enhancement of treatment strategies.

Association of TLR9-1237T>C; rs5743836 polymorphism with increased risk of Hodgkin’s lymphoma: A case-control study

Mature B-cell neoplasms are typically divided into Hodgkin and Non-Hodgkin Lymphomas. Hodgkin Lymphoma is characterized by the neoplastic Reed-Sternberg cells, usually harbored in an inflammatory background, with a frequent clinical presentation of mediastinal lymphadenopathy. Many studies link between autoimmunity and lymphomagenesis, a large proportion of these studies evidently trace the pathogenesis back to the misdirected detection of self-derived nucleic acids by Toll-Like Receptors (TLRs), especially those of the intracellular type. In this study, we analyzed the relationship between a selected SNP in TLR9 (TLR9-1237T>C; rs5743836) and the risk and overall survival of HL patients in a Jordanian Arab population. A total of 374 subjects; 136 cases of Hodgkin lymphoma and 238 matched healthy controls were incorporated in this study. Genomic DNA was extracted from formalin-fixed paraffin-embedded tissues. Genotyping of the genetic polymorphisms was conducted using a sequencing protocol. The results show a statistically significant higher distribution of the rs5743836 (TLR9-1237T>C) allele among the case population, with a p-value of 0.031 (<0.05). This distribution proved significant when studied in the codominant (only significant in the T/C genotype, p-value = 0.030), dominant (p-value = 0.025), and overdominant (p-value = 0.035) models. None of the models showed any statistically significant difference in survival associated with the rs5743836 (TLR9-1237T>C) SNP.

Genomic characterization of lymphomas in patients with inborn errors of immunity

Inborn errors of immunity-associated lymphomas are characterized by distinct clinical features and genetic signatures.

Both germline and somatic alterations contribute to lymphomagenesis in patients with inborn errors of immunity.

Patients with inborn errors of immunity (IEI) have a higher risk of developing cancer, especially lymphoma. However, the molecular basis for IEI-related lymphoma is complex and remains elusive. Here, we perform an in-depth analysis of lymphoma genomes derived from 23 IEI patients. We identified and validated disease-causing or -associated germline mutations in 14 of 23 patients involving ATM, BACH2, BLM, CD70, G6PD, NBN, PIK3CD, PTEN, and TNFRSF13B. Furthermore, we profiled somatic mutations in the lymphoma genome and identified 8 genes that were mutated at a significantly higher level in IEI-associated diffuse large B-cell lymphomas (DLBCLs) than in non-IEI DLBCLs, such as BRCA2, NCOR1, KLF2, FAS, CCND3, and BRWD3. The latter, BRWD3, is furthermore preferentially mutated in tumors of a subgroup of activated phosphoinositide 3-kinase δ syndrome patients. We also identified 5 genomic mutational signatures, including 2 DNA repair deficiency-related signatures, in IEI-associated lymphomas and a strikingly high number of inter- and intrachromosomal structural variants in the tumor genome of a Bloom syndrome patient. In summary, our comprehensive genomic characterization of lymphomas derived from patients with rare genetic disorders expands our understanding of lymphomagenesis and provides new insights for targeted therapy.

Incidence patterns and review of Hodgkin lymphoma in the Republic of Armenia

Hodgkin lymphoma (HL) accounts for roughly 10% of all lymphomas and 0.6% of all malignant tumours analysed worldwide yearly. Data regarding HL in developing world are exceptionally constrained. The main objective of this research is to investigate the incidence patterns of HL within the Republic of Armenia and to portray disease distribution according to age and sex. There is a very strict evidence on the frequency of HL in Armenia. The results of our research find out that the frequency of HL in Armenia has not changed altogether over the past 15 years and is comparable to that detailed from the USA and Europe.

Clinicopathologic features and therapy outcome in childhood Hodgkin's lymphoma: a report from tertiary care center in Saudi Arabia

BACKGROUND

Hodgkin lymphoma (HL) is lymphoid neoplasm usually affecting lymphatic system; it accounts 3.6% of cancers in Saudi Arabia. Modern treatment protocols had shown particular success rates in overall-survival (OS) and event-free-survival (EFS). In our study, we reviewed the medical records of 80 pediatric and young adolescent patients diagnosed HL from January 2006 to July 2020, treated at tertiary care hospital in Riyadh, Saudi Arabia. Demographic, clinical, and pathological data were explored. First line therapy was ABVD, COG, COPP, R-CHOP, or radiotherapy alone in 53/80 (66.4%), 24/80 (30%), 1/80 (1.2%), 1/80 (1.2%), or 1/80 (1.2%) patients; respectively. Response assessment was done by CT + / - PET scan after first 2 cycles then every 2 cycle and end of therapy. Another assessment was done if any clinical suspicion of recurrence.

RESULTS

Median age 11 (range 3-16) years. Males to females 1.3:1. Seventy-two out of eighty (90%) patients showed first complete remission (CR1) and maintained remission for median 40 (range 7-136) months. Eight out of eighty (10%) patients showed refractory disease. Nineteen patients received salvage therapy (ICE or ESHAP/brentuximab vedotin or gemcitabine/brentuximab vedotin), 14/19 (73.7%) had 2nd complete remission (CR2) for median time 24 (ranged 9-78) months, while 5/19 (26.3%) did not show any response. Five-year OS and EFS were 95% and 75%. Two patients had 2ry malignant neoplasms, one had AML and died, the other had malignant fibrous histocytoma and still alive. None of our patients had fertility problem. Also, they did not experience chronic pulmonary or cardiotoxicity. Classic Hodgkin's lymphoma: nodular sclerosis subtype was more prominent (55%) than mixed cellularity subtype (22.5%), which is similar to several European and US studies, lymphocyte rich (11.25%) and lymphocyte depleted (0%), while nodular lymphocyte predominant Hodgkin's lymphoma (11.25%).

CONCLUSIONS

Our study provided unique descriptive study of childhood HL, in Saudi Arabia, with valuable insight into the long-term outcome and late toxicity. Our results are comparable to other studies in the Middle East and European countries.

Social gradient predicts survival disadvantage of African Americans/Black children with lymphoma

BACKGROUND

Cancer is the leading cause of disease-related mortality among children, 0-14 years, and lymphoma, a malignant neoplasm of the lymphoid cells, mostly lymphatic B and T cells is common among children. The current study aimed to assess the cumulative incidence (CmI), mortality, and survival in pediatric lymphoma.

MATERIALS AND METHODS

A retrospective cohort was utilized to examine children, 0-19 years with lymphoma for CmI, mortality and survival from the Surveillance, Epidemiology, and End Results (SEER) data. The variables assessed included social determinants of health, namely urbanity, median household income, and race. While chi square was used to characterize study variables by race, binomial regression was employed for mortality risk. The Cox proportional hazard model was used for survival modeling.

RESULTS

The CmI was higher among white children (76.67%) relative to Black/African American (AA, 13.44%), American Indian/Alaskan Native (AI/AN, 0.67%), as well as Asian/Pacific Islander (A/PI, 7.53%). With respect to mortality, there was excess mortality among Black/AA children compared to white children, Risk Ratio (RR) = 1.54, 95% CI, 1.33-1.79. Relative to whites, Blacks were 52% more likely to die, Hazard Ratio (HR) = 1.52, 95% CI, 1.30-1.78. Survival disadvantage persisted among Blacks/AA after controlling for the other confoundings, adjusted hazard ratio (aHR) = 1.54, 99% CI, 1.24-1.91.

CONCLUSION

In a large cohort of children with lymphoma, Black/AA children relative to whites presented with survival disadvantage, which was explained by urbanity and median household income, suggestive of transforming the physical and social environments in narrowing the racial differences in pediatric lymphoma survival in the US.

Risk factors for Epstein Barr virus-associated cancers: a systematic review, critical appraisal, and mapping of the epidemiological evidence

BACKGROUND

Epstein Barr Virus (EBV) infects 90%-95% of all adults globally and causes ~ 1% of all cancers. Differing proportions of Burkitt's lymphoma (BL), gastric carcinoma (GC), Hodgkin's lymphoma (HL) and nasopharyngeal carcinoma (NPC) are associated with EBV. We sought to systematically review the global epidemiological evidence for risk factors that (in addition to EBV) contribute to the development of the EBV-associated forms of these cancers, assess the quality of the evidence, and compare and contrast the cancers.

METHODS

MEDLINE, Embase and Web of Science were searched for studies of risk factors for EBV-associated BL, GC, HL and NPC without language or temporal restrictions. Studies were excluded if there was no cancer-free comparator group or where analyses of risk factors were inadequately documented. After screening and reference list searching, data were extracted into standardised spreadsheets and quality assessed. Due to heterogeneity, a narrative synthesis was undertaken.

RESULTS

9916 hits were retrieved. 271 papers were retained: two BL, 24 HL, one GC and 244 NPC. The majority of studies were from China, North America and Western Europe. Risk factors were categorised as dietary, environmental/non-dietary, human genetic, and infection and clinical. Anti-EBV antibody load was associated with EBV-associated GC and BL. Although the evidence could be inconsistent, HLA-A alleles, smoking, infectious mononucleosis and potentially other infections were risk factors for EBV-associated HL. Rancid dairy products; anti-EBV antibody and EBV DNA load; history of chronic ear, nose and/or throat conditions; herbal medicine use; family history; and human genetics were risk factors for NPC. Fresh fruit and vegetable and tea consumption may be protective against NPC.

CONCLUSIONS

Many epidemiological studies of risk factors in addition to EBV for the EBV-associated forms of BL, GC, HL and NPC have been undertaken, but there is a dearth of evidence for GC and BL. Available evidence is of variable quality. The aetiology of EBV-associated cancers likely results from a complex intersection of genetic, clinical, environmental and dietary factors, which is difficult to assess with observational studies. Large, carefully designed, studies need to be strategically undertaken to harmonise and clarify the evidence.

REGISTRATION

PROSPERO CRD42017059806.

Five-year follow-up of SWOG S0816: limitations and values of a PET-adapted approach with stage III/IV Hodgkin lymphoma

Patients with advanced-stage Hodgkin lymphoma (HL) demonstrated excellent 2-year progression-free survival (PFS) after receiving positron emission tomography (PET)-adapted therapy on SWOG S0816. Patients received 2 cycles of doxorubicin, bleomycin, vinblastine, and dacarbazine (ABVD). Patients achieving complete response (CR) on PET scan following cycle 2 of ABVD (PET2) continued 4 additional cycles of ABVD. Patients not achieving CR on PET2 were switched to escalated bleomycin, etoposide, doxorubicin, cyclophosphamide, vincristine, procarbazine, and prednisone (eBEACOPP) for 6 cycles. After a median follow-up of 5.9 years, a subset of 331 eligible patients with central review of PET2 was analyzed. PET2 was negative in 82% and positive in 18%. For all patients, the estimated 5-year PFS and OS was 74% (95% confidence interval [CI], 69%-79%) and 94% (95% CI, 91%-96%), respectively. For PET2- and PET2+ patients, the 5-year PFS was 76% (95% CI, 70%-81%) and 66% (95% CI, 52%-76%), respectively. Seven (14%) and 6 (2%) patients reported second cancers after treatment with eBEACOPP and ABVD, respectively (P = .001). Long-term OS of HL patients treated on S0816 remains high. Nearly 25% of PET2- patients experienced relapse events, demonstrating limitations ABVD therapy and of the negative predictive value of PET2. In PET2+ patients who received eBEACOPP, PFS was favorable, but was associated with a high rate of second malignancies compared with historical controls. Our results emphasize the importance of long-term follow-up, and the need for more efficacious and less toxic therapeutic approaches for advanced-stage HL patients. This trial was registered at www.clinicaltrials.gov as #NCT00822120.

CD163 is a predictive biomarker for prognosis of classical Hodgkin's lymphoma in Saudi patients

Hodgkin's lymphoma (HL) is a hematological malignancy characterized by a minority of neoplastic cells outnumbered by tumor-associated macrophages (TAMs). The overexpression of the CD163 antigen by TAMs is considered to be a significant predictive biomarker for risk stratification. This is likely caused by a genetic single-nucleotide polymorphism (SNP) at the gene promoter. The aim of the present retrospective case-control study was to establish a gene expression profile of a specific biomarker for classical HL (CHL) in order to predict the outcome and survival of CHL patients in Saudi Arabia. The protein expression of CD163 on TAMs was studied using immunohistochemistry (IHC). A prognosis index was calculated for the CD163 protein to assess the risk stratification of CHL. Genotyping of selected SNPs of this antigen was performed for 100 CHL cases and controls. The analysis revealed that the CD163 protein expression level was significantly correlated with disease relapse (DR) and overall survival (OS). In addition, the CD163 index threshold (15.0) was found to be significantly correlated with the relapse rate. Among the studied CD163 SNPs, rs75608120 exhibited a significant correlation with the DR rate of CHL patients, but not with OS. The findings of the present study confirmed that CD163 is a specific marker for TAMs, and its overexpression by TAMs is significantly associated with relapse and reduced survival post-therapy. In addition, a new methodology of indexing CD163 protein expression for HL risk stratification was proposed. Thus, the present study identified a specific predictive molecular and antigenic biomarker for CHL prognosis.

Overall survival of classical Hodgkins lymphoma in Saudi patients is affected by XPG repair gene polymorphism

In Hodgkin's lymphoma (HL), single nucleotide polymorphisms (SNPs) of specific DNA repair genes have been identified to have an important role in the risk of HL. Consequently, they may also serve an important role in HL prognosis and disease outcome. The present study aimed to define an SNP molecular profile, based on DNA repair genes mutations, as predictive biomarkers for the prognostic outcome of patients with Classical HL (CHL) in Saudi Arabia. Genotyping of selected SNPs located in selected DNA repair genes was performed on 100 CHL cases and an equivalent number of healthy controls. No significant associations between CHL disease relapse (DR) or overall survival (OS) and 4 DNA repair genes were observed, with the exception of xeroderma pigmentosum, complementation group G (XPG) repair gene SNP (rs17655), which revealed a statistically significant association with CHL patient survival (P=0.036). Accordingly, these data suggest that the XPG gene may be a useful predictive molecular genetic biomarker for CHL clinical outcome. The present study also provided valuable insights on the contribution of DNA repair genes in Saudi patients with CHL. To the best of our knowledge, we defined for the first time, a specific genetic pattern associated with CHL outcome was defined in the present study in Saudi patients.

Evidence of EBV infection in lymphomas diagnosed in Lusaka, Zambia

INTRODUCTION

Epstein-Barr virus (EBV) is a ubiquitous virus that infects more than 90% of the world's population, and is implicated in lymphoma pathogenesis. However, in Zambia during the diagnosis of these lymphomas, the association of the virus with the lymphomas is not established. Since most patients with lymphomas have poor prognosis, the identification of the virus within the lymphoma lesion will allow for more targeted therapy. The aim of this study was to provide evidence of the presence of the EBV in lymphomas diagnosed at the University Teaching Hospital (UTH) in Lusaka, Zambia.

METHODS

One hundred and fifty archival formalin-fixed paraffin embedded suspected lymphoma tissues stored over a 4-year period in the Histopathology Laboratory at the UTH in Lusaka, Zambia, were analysed. Histological methods were used to identify the lymphomas, and the virus was detected using Polymerase Chain Reaction (PCR). Subtyping of the virus was achieved through DNA sequencing of the EBNA-2 region of the viral genome. Chi square or fisher's exact test was used to evaluate the association between EBV status, type of lymphoma and gender.

RESULTS

The majority of the lymphomas identified were non-Hodgkin's lymphoma (NHL) (80%) followed by Hodgkin's lymphoma (HL) (20%). EBV was detected in 51.8% of the cases, 54.5% of which were associated with NHL cases, while 40.9% associated with HL cases. The predominant subtype of the virus in both types of lymphomas was subtype 1. One of the lymphoma cases harboured both subtype 1 and 2 of the virus.

CONCLUSION

This study showed that EBV is closely associated with lymphomas. Therefore, providing evidence of the presence of the virus in lymphoma tissues will aid in targeted therapy. To our knowledge this is the first time such data has been generated in Zambia.

Distinct subtype distribution and somatic mutation spectrum of lymphomas in East Asia

PURPOSE OF REVIEW

Here, we give an updated overview of the subtype distribution of lymphomas in East Asia and also present the genome sequencing data on two major subtypes of these tumors.

RECENT FINDINGS

The distribution of lymphoma types/subtypes among East Asian countries is very similar, with a lower proportion of B-cell malignancies and a higher proportion of T/natural killer (NK)-cell lymphomas as compared to Western populations. Extranodal NK/T-cell lymphoma is more frequently observed in East Asia, whereas follicular lymphoma and chronic lymphocytic leukemia, are proportionally lower. The incidence rate of lymphoma subtypes in Asians living in the US was generally intermediate to the general rate in US and Asia, suggesting that both genetic and environmental factors may underlie the geographical variations observed.Key cancer driver mutations have been identified in Asian patients with diffuse large B-cell lymphoma or extranodal NK/T-cell lymphoma through genome sequencing. A distinct somatic mutation profile has also been observed in Chinese diffuse large B-cell lymphoma patients.

SUMMARY

The incidence and distribution of lymphoma subtypes differed significantly between patients from East Asia and Western countries, suggesting subtype-specific etiologic mechanisms. Further studies on the mechanism underlying these geographical variations may give new insights into our understanding of lymphomagenesis.

Nonrandom occurrence of lymphoid cancer types in 140 families

We studied 140 families with two or more lymphoid cancers, including non-Hodgkin lymphoma (NHL), Hodgkin lymphoma (HL), chronic lymphocytic leukemia (CLL), and multiple myeloma (MM), for deviation from the population age of onset and lymphoid cancer co-occurrence patterns. Median familial NHL, HL, CLL and MM ages of onset are substantially earlier than comparable population data. NHL, HL and CLL (but not MM) also show earlier age of onset in later generations, known as anticipation. The co-occurrence of lymphoid cancers is significantly different from that expected based on population frequencies (p < .0001), and the pattern differs more in families with more affected members (p < .0001), suggesting specific lymphoid cancer combinations have a shared genetic basis. These families provide evidence for inherited factors that increase the risk of multiple lymphoid cancers. This study was approved by the BC Cancer Agency - University of British Columbia Clinical Research Ethics Board.

Different time trends by gender for the incidence of Hodgkin's lymphoma among young adults in the USA: a birth cohort phenomenon

OBJECTIVES

Hodgkin's lymphoma (HL) is one of the most common cancers among young adults. We investigated the time trends for HL among the 20-44 age group in the USA by gender to identify the potential factors accounting for the incidence trends.

METHODS

Using data from the National Cancer Institute's Surveillance, Epidemiology, and End Results program for 1973-2010, we conducted age-period-cohort modeling to evaluate birth cohort patterns on incidence trends of HL over time.

RESULTS

For all races combined, the age-adjusted incidence patterns were similar to that of whites. The birth cohort patterns for whites and all races were similar, but the patterns differed according to gender. Specifically, except for the 1970-1975 birth cohort, all other birth cohorts showed an increasing birth cohort trend for females. Conversely, there was a decreasing cohort trend in males beginning in the 1960 birth cohort regardless of the assumptions of the period effect.

CONCLUSION

The established risk factors for HL can seemingly not explain the gender disparities of the cohort pattern, which necessitates further analytical epidemiological studies to explore the risk factors for this disease with respect to potential differences by gender and by histological subtype.

Meta-analysis of the association between cigarette smoking and incidence of Hodgkin's Lymphoma

INTRODUCTION

Previous studies have suggested a relationship between smoking and Hodgkin's lymphoma (HL). The main objective of this study was to evaluate this potential association with a meta-analysis of observational studies.

PATIENTS AND METHODS

A literature search was undertaken through December 2010 looking for observational studies evaluating the association between smoking and HL. From 714 articles, 17 were included in this study. Outcome was calculated and reported as odds ratio (OR). Heterogeneity was assessed by using the I(2) index. Publication bias was evaluated by trim-and-fill analysis. Quality assessment was performed with the Newcastle-Ottawa scale.

RESULTS

Our analysis showed an OR of developing HL of 1.35 (95% CI, 1.17 to 1.56; P < .001) in current smokers. Former smokers did not have an increased risk of HL. In subset analyses of current smokers, men and older individuals had ORs of HL of 1.78 (95% CI, 1.46 to 2.17; P < .001) and 1.77 (95% CI, 1.23 to 2.54; P = .002), respectively. In addition, the OR of HL was increased in individuals who smoke more than 20 cigarettes per day, have smoked more than 20 years, or have smoked more than 15 pack-years at 1.51 (95% CI, 1.16 to 1.98; P = .002), 1.84 (95% CI, 1.47 to 2.32; P < .001), and 1.97 (1.53 to 2.54; P < .001), respectively. Meta-regression analyses showed a relative OR of HL of 1.007 (95% CI, 1.001 to 1.013; P = .025) per cigarette per day and of 1.013 (95% CI, 1.006 to 1.019; P < .001) per year of smoking.

CONCLUSION

Smoking seems to increase the odds of developing HL in current smokers. The risk of HL is higher in men and older individuals and increases with higher intensity and longer duration of smoking.

Incidence patterns and outcomes for hodgkin lymphoma patients in the United States

Hodgkin lymphoma (HL) demonstrates heterogenous histologic findings, clinical presentation, and outcomes. Using the United States Surveillance, Epidemiology, and End Results (SEER) data we examined relationships between patient characteristics, clinical features at diagnosis, and survival in HL patients. From 2000 to 2007, 16,710 cases were recorded in 17 SEER registries. Blacks and Asians had low incidence (black/white incidence rate ratio (IRR) 0.86, P < .01; Asian/white IRR 0.43, P < .01). The bimodal pattern of incidence was less prominent for black males. Asians and Blacks presented at a mean age of 38 years compared to 42 years for Whites (P < .001). Race was a predictor for survival with HR of 1.19 (95% CI 1.11-1.28) for Blacks. Age was the most important predictor of survival (HR for patients ≥45 years 5.08, 95% CI 4.86-5.31). These current patterns for presentation and outcomes of HL help to delineate key populations in order to explore risk factors for HL and strategies to improve treatment outcomes.