A Twenty Years Epidemiology Study of 2nd Hematological Malignancies Post to the Initial Tumor Treatment: Report from Southern China Single Cancer Group
Authors: Chen Siliang , Qin Zheyuan , Liang Stephen 
Published: October 2019

Abstract
Objective: To investigate the clinical features of 2nd hematological malignancies post to the initial cancer treatment.
METHODS: A retrospective study was performed to analyze the available clinical data of 116 patients diagnosed with 2nd hematologic malignancies after treatment of various malignant tumors from June 1998 to June 2018 at Sun Yat-sen University cancer center.
RESULTS: The characteristics of the 116 patients diagnosed with 2nd hematological cancer post to initial cancer treatment were indicated as following: 62 males and 54 females. The primary tumor category was grouped as (according to ICD-10 International Disease Code): i) 23 cases of head and neck malignant tumors (14 cases of nasopharyngeal carcinoma (C11), 3 cases of laryngeal carcinoma (C32), 3 cases of thyroid carcinoma (C73), 3 cases of other head and neck tumors (C00-10, 12-13), ii) 7 cases of chest malignant tumors (2 cases of esophageal cancer(C15), 4 cases of lung cancer and bronchial carcinoma (C33-34), 1 case of chest wall tumor(C49), iii) 31 cases of GI malignant tumor (7 cases of gastric cancer(C16), 7 cases of hepato-biliary cancer(C22-24), 17 cases of intestinal cancer(C18-21), iv) 17 cases of breast cancer (C50), v) 12 cases of gynecological malignancies (4 cases of ovarian cancer, 7 cases of cervical cancer, 1 case of endometrial cancer), vi) 7 cases of malignant genitourinary tumor (C61-68), vii) 15 cases of hematological malignancies (12 cases of lymphoma(C81-85), 3 cases of chronic lymphocytic leukemia(C91.101) ), viii) others: 2 cases of sarcoma (C80 03), 1 case of melanoma (C43), 1 case of glioma. The subtype of 2nd hematological malignancies were indicated as following: 33 patients with acute myeloid leukemia, 9 patients with myelodysplastic syndrome, 8 patients with acute lymphoblastic leukemia, 4 patients with chronic lymphocytic leukemia, 3 patients with chronic myeloid leukemia, and 2 patients with multiple myeloma. The rest 57 cases were non-Hodgkin's lymphoma.
The median duration time for the 116 patients from starting treatment of the first tumor to the happening of the secondary hematologic tumor was 51 (range: 7-297) months, with an overall survival time 32 (range: 1-114) months. For the 50 cases diagnosed with 2nd acute leukemia and myelodysplastic syndrome, the interval period time was 33 (range: 7-167) months. The overall survival time for the 50 cases is 12 (range: 1-61) months. The 1-year and 3-year overall survival rate was 44.5% and 11.7%, respectively.
Interestingly, of the patients' initial treatment options among the 50 cases, eight patients did not receive radiotherapy and chemotherapy beside surgery removal of the 1st tumor. The mean survival was 36.7 ± 12.1 months in the non-radiotherapy or non-chemotherapy group (N=8) while 12.1 ± 1.9 months in the radiotherapy and/or chemotherapy group (N=42; P = 0.032). At diagnosis of the 2nd hematological cancer of the 50 patients, i) 77% of patients had the decreased platelet count and 60% had grade III-IV platelet thrombocytopenia; ii) 82.5% of patients had elevated or decreased white blood cells count: while 40% patients had increased white blood cells >20*10^9/L, 22.5% cases had grade III-IV leukopenia; There are 72.5% patients has anemia with Hgb<9g/dL.
The median duration time from the initial 1st tumor treatment to the occurrence of the 2nd non-Hodgkin's lymphoma (N=57) was 74 (range: 7-297) months, with a median survival time of 65 (range: 1-114) months. The 1-year, 3- year and 5-year overall survival rate were 85.6%, 70.5%, 56.3%, respectively. For the diagnosis of 2nd non-Hodgkin's lymphoma, 3.5% (2/57) of the patients were found by annual physicals, 61.4% (35/57) patients presented with superficial lymphadenopathy and 35.1% (20/57) cases complains of non-specific systemic symptoms: fever, night sweating, and decreased body weight.
Conclusion: In general, the outcome of secondary hematological tumors is poor. However, patients who did not receive chemo- or radiotherapy during the initial tumor treatment had a longer survival than those who did. The risk factors, potentially type of chemo-agent and cumulative dosage of drugs, which may contribute to the occurrence of 2nd hematological malignancies, should be fully explored before formulating the initial tumor treatment plan.

Disclosures
No relevant conflicts of interest to declare.