Incidence of Second Malignancies in the History of Chronic Lymphocytic Leukemia

Introduction

The occurrence of other neoplasms in patients diagnosed with chronic lymphocytic leukemia (CLL) is a known but insufficiently studied complication, highlighting the need for further research.

Our study aims to analyze the incidence of other malignancies in CLL.

Methods

We performed a retrospective observational study of patients diagnosed with CLL between 2000-2016 at our center.

Variables collected included: demographics, stage at diagnosis, treatment, response to treatment, death, other neoplasm (type, date of diagnosis, outcome), biomarker profiles studied by karyotyping, FISH, immunoglobulin heavy chain gene variable region mutational status, and TP53 mutational status.

A descriptive study was performed. Quantitative variables are described as medians with their range, and qualitative variables as percentages. The relationship between qualitative variables and the development of second malignancies was performed using Chi-square and Fisher's exact test. Survival analyses were performed using the Kaplan-Meier method and the difference between groups was analyzed using the log-rank test.

Results

A total of 182 patients were evaluated, 104 men (57%) and 78 women (43%); median age: 74 years (39 - 97). Most patients were diagnosed at early stages (74% at Rai stage 0 and 84% at Binet stage A) and the median CIRS scale score at diagnosis was 4 (0 - 15).

With a median follow-up of 76 months (20-212), 77/182 (42%) patients had received ≥1 line(s) of treatment: 1: 53%, 2: 26%, 3: 8%, ≥4: 13%.

Forty-nine cases (27%) were reported with other malignancies in addition to CLL; cases with Richter transformation (n=5, 2.7%) were excluded.

The diagnosis of CLL preceded the other neoplasm in 33/182 cases (18%): 8 hematologic and 27 non-hematologic neoplasms. Half of the hematologic malignancies involved MGUS (n=4), 1 mutated JAK2 (V617F) cMPN, 1 AML and 1 MALT lymphoma. As for non-hematologic tumors, non-melanoma skin cancer accounted for 30% of cases (n=8), followed by breast cancer (n=5, 18.5%). Neoplasms of the stomach, colon, liver, bladder and prostate together accounted for 37%, in the same proportion each (n=2, 7.4%). The remaining neoplasms corresponded to lung and bronchus, kidney, melanoma and pancreas. Five of the 27 patients had a third solid organ neoplasm, with non-melanoma skin cancer again being the most frequent (n=2). The other neoplasms were lung, small bowel and thyroid.

The incidence of second neoplasms was higher in treated patients (26% vs. 12.4%, p=0.019). The incidence of a second hematologic malignancy was related to treatment administration (9%) compared to 1% in untreated patients (p=0.011), especially in those with ≥ 3 lines (37.5% vs. 3%), p=0.024. We could not find any association between the variables analyzed and the development of second non-hematologic malignancies.

The development of second neoplasms after the diagnosis of CLL did not have a negative impact on the overall survival of these patients.

Conclusions

The incidence of second malignancies is high in patients with CLL, being higher in those patients who have received treatment, and especially in those with a greater number of lines received. In contrast, the development of solid tumors did not seem to be affected by treatment administration, which should motivate further investigation in specific subgroups of patients. In our series, the development of second neoplasms after the diagnosis of CLL did not have a negative impact on the overall survival of these patients.