Variation in the seasonal diagnosis of acute lymphoblastic leukemia: evidence from Singapore, the United States, and Sweden

Monthly variation in diagnosis of acute lymphoblastic leukemia and survival outcome in children and adults: 15-year trends at a single center

BACKGROUND

The date of acute lymphoblastic leukemia (ALL) diagnosis has been studied regarding potential etiologic roles with contrasting results and the issue remains controversial. The principal aim of this study was to analyze monthly variation of ALL diagnosis in a large homogenous Hispanic Latin American cohort over 15 years; its association with survival rates was also assessed.

METHODS

Clinical files and electronic records of 501 consecutive patients of all ages with ALL in northeastern Mexico over the years of 2004-2018 were scrutinized. Patients were divided into children ≤18 and adults >18 years. The Chi-square heterogeneity analysis was used to test for non-uniform variation. The Poisson regression analysis was used to fit sinusoidal (harmonic) models to the data, using the month of diagnosis as a covariate in a separate model.

RESULTS

During the study period 363 children (72.5%) and 138 adults (27.5%) (p < 0.001) were diagnosed with ALL. Heterogeneity across the months of diagnosis was confirmed (p = 0.019) and the Poisson regression analysis confirmed a significant monthly variation (p < 0.001) (95% CI, 3.024-3.745), a higher annual peak being observed in the month of March (p = 0.002), followed by a second peak in October (p = 0.026). The five-year OS for children was 68.2% (95% CI, 67.64-68.74) and for adults, 43.7% (95% CI, 42.67-44.71) (p < 0.001). No significant association between the month of diagnosis and OS was found (p = 0.789).

CONCLUSION

The monthly variation of ALL diagnosis was documented; these results confirm the heterogeneous behavior of the disease and appear to be consistent with an interplay of environmental and biologic factors. Further studies are needed to examine putative candidate agents.

Seasonal variations in hematological disorders: A 10-year single-center experience

AIMS

To assess the seasonal variations in hematological disorders among patients diagnosed on the basis of bone marrow biopsy, who attended National Institute of Blood Diseases (NIBD) clinics during 2006 to 2015.

METHODS

We retrospectively reviewed the 10-year records of hematological disorders among patients' NIBD clinics from year 2006 to 2015. All cases of aplastic anemia (AA), acute lymphoblastic leukemia (ALL), acute myeloid leukemia (AML), immune thrombocytopenic purpura (ITP), and acute promyelocytic leukemia (APML) were categorized on the basis of the seasons in which they were diagnosed such as winter (December-February), spring (March-May), southwest monsoon periods (June-September), and retreating monsoon period (October and November). Statistical analysis was performed by using SPSS and STATA. Inferential statistics were explored using the chi-square test for heterogeneity to evaluate seasonal variations. P-value <0.05 was taken as significant.

RESULTS

A total of 1982 cases were reviewed. Men were predominantly higher (n = 1190, 60%) as compared to women (n = 792, 40%). Frequency of ALL was found to be higher (513, 25.9%), followed by ITP (504, 25.4%), AML (490, 24.7%), AA (396, 20%), while APML was observed in only 79 (4%) patients. Seasonal variations in the diagnosis of hematological disorders were observed (P-value < .001), except in APML diagnosis (P-value = .445). Significant seasonal variations were also detected in both genders in stratified analysis.

CONCLUSION

The finding of this study has reported an increase in the hematological disorder during 2006 to 2015. Particularly, majority of the cases were reported in southwest monsoon period, whereas least cases were reported in retreating period. Significant seasonal and yearly variations were detected in all diagnosis except the APML.

Clinical characteristics of acute lymphoblastic leukemia in male and female patients: A retrospective analysis of 705 patients

The aim of the present study was to compare the clinical characteristics of acute lymphoblastic leukemia (ALL) that occurred in male and female patients at one institution in Southern China. The medical electronic records of Nanfang Hospital, affiliated to Southern Medical University, were searched for patients with a definite diagnosis of ALL that were diagnosed between January 1, 2001 and December 31, 2012. The clinical data of the patients were collected and analyzed. A total of 705 eligible patients were identified. The gender ratio of male to female patients was 1.84:1. The average ages at the time of diagnosis were 16.43 and 19.54 years for male and female patients, respectively (P=0.007). No significant differences were identified in the seasonal occurrence distribution, blood group distribution or ratio for the presence of the Ph chromosome between males and females. However, a higher incidence of T-cell type ALL was identified in males (P=0.023). The present study reveals that ALL demonstrates a male predominance, but similar clinical characteristics of ALL are present in males and females in Southern China.

From a different angle: a novel approach to health valuation

The value of a health state is typically described relative to the value of an optimal state, specifically as a ratio ranging from unity (equal to optimal health) to negative infinity. Incorporating potentially infinite values is a challenging issue in the econometrics of health valuation. In this paper, we apply a directional statistics approach based on the assumption of wavering preference. Unlike ratio statistics, directional statistics are based on polar coordinates (angle, radius). The range of angles is bounded between 45 degrees (unity) and negative 90 degrees (i.e., negative infinity); therefore, mean angles are well behaved and negate the impetus behind arbitrary data manipulations. Using time trade-off (TTO) responses from the seminal Measurement and Valuation of Health study, we estimate 243 EQ-5D health state values by minimizing circular variance with and without radial weights. For states with published values greater than zero (i.e., better-than-death), the radially weighted estimates are nearly identical to the published values (Mean Absolute Difference 0.07; Lin's rho 0.94). For worse-than-death states, the estimates are substantially lower than the published values (Mean Absolute Difference 0.186; Lin's rho 0.576). For the worst EQ-5D state (33333), the published value is -0.59 and the directional estimate is -1.11. By taking a directional statistics approach, we circumvent problems inherent to ratio statistics and the systematic bias introduced by arbitrary data manipulations. The predictions suggest that published estimates overvalue severe states. This paper examines TTO responses; however, it may be extended to all forms of health valuation.

The changing scene of adult acute lymphoblastic leukemia

PURPOSE OF REVIEW

The review focuses on the most recent advances in the diagnostic and prognostic work-up of adult acute lymphoblastic leukemia (ALL) and its implications in the clinical management of the disease.

RECENT FINDINGS

ALL can be identified on the basis of morphologic, cytochemical and immunophenotypic criteria; modern management of ALL is also based on cytogenetic and genetic evaluations. New technologies, such as gene expression profile analysis, may allow us to further unravel the intrinsic biology of the disease, to improve diagnostic and prognostic stratification, and to design innovative therapeutic strategies. In potentially all cases, specific markers of the disease can be found and utilized together with the rearrangement of immunoglobulin and T-cell receptor genes to monitor minimal residual disease during clinical follow-up. These biologically-defined subgroups of patients may have a different clinical course, response to treatment and variable prognosis.

SUMMARY

Recent biologic advancements are progressively realising the possibility of designing targeted and individualized therapeutic strategies according to the more refined, molecularly defined features of leukemic cells and the presence or absence of residual disease in adult ALL.

On the evidence for seasonal variation in the onset of acute lymphoblastic leukemia (ALL)

Inconsistent seasonal patterns in peak presentation of acute lymphoblastic leukemia have been reported but no formal synthesis of published reports has been attempted to date. We extracted monthly tabulations of cases from publications and reanalysed using an angular methodology and the von Mises distribution. Twenty-four articles from 11 countries in locations ranging from 35.05 degrees S to 65.01 degrees N were identified. Formal synthesis established weak evidence for seasonality in adults and children. Were seasonality present, and arising from a climatic determinant, one might anticipate peaks of an increasing magnitude as the associated latitude moved away from the equator. No such pattern was apparent.

Pattern of haematological diseases diagnosed by bone marrow examination in Yemen: a developing country experience

There is lack of information about the relative prevalence of haematological disorders in Yemen and other Middle East countries. The aim of this study was to evaluate the pattern of haematological diseases diagnosed by bone marrow examination in Yemen considering the limited diagnostic facilities. At the referral haematology centre in Yemen, between November 1999 and November 2005, 785 patients >14 years old were evaluated by bone marrow examination. Relevant investigations were performed when needed. A total of 627 patients had haematological disorders other than lymphoma, and their data were analysed. There were 273 females and 354 males. A total of 159 patients had Acute myeloid leukaemia, 75 had acute lymphocytic leukaemia, 87 had chronic myeloid leukaemia, 36 chronic lymphocytic leukaemia, eight had multiple myeloma, 13 myelodysplastic syndromes, seven myelofibrosis, seven polycythaemia vera, three primary thrombocythaemia, two hairy cell leukaemia, two metastases, 36 aplastic anaemia, 29 immune thrombocytopenic purpura (ITP), nine autoimmune haemolytic anaemia, three pernicious anaemia, 65 iron deficiency anaemia, 57 megaloblastic anaemia and malaria, 18 mixed deficiencies, and 11 patients had visceral leishmaniasis. Sex- and age-related distribution of the various disorders was also presented. In conclusion, the leukaemias were the most frequently encountered diagnosis followed by iron deficiency anaemia, megaloblastic anaemia and malaria, aplastic anaemia and ITP respectively. The other haematological disorders were less common. These findings are comparable with that seen in other developing and developed countries.