CLL-069: Incidence of Second Cancer in Patients with Chronic Lymphocytic Leukemia: The Indian Scenario

Abstract

Context: Chronic lymphocytic leukemia (CLL) is the most common leukemia in adults in the west; however, it is relatively infrequent in India. Patients with CLL have two times higher incidence of second malignancies (SM) than the general population. Objective: Our study aims to evaluate the incidence of SM in Indian patients. Design and Setting: We retrospectively screened 589 patients with CLL registered in the Department of Medical Oncology at All India Institute of Medical Sciences (AIIMS), New Delhi, India, over a period of 20 years (2000–2019) and found 60 cases of SM. SM was defined as another malignancy or transformation at the time of diagnosis or during follow-up. SM was divided into two categories: hematologic malignancies and solid tumors. Results: With a median follow-up of 48 months, a total of 60 SM cases were identified. Forty-eight cases (80%) were hematological malignancies, and 12 cases (20%) were solid tumors. The median age was 55 years (28–72 years). There were 43 males and 17 females. The median total leukocyte count at presentation was 55×109/L. The clinical Rai stage distribution was stage 0 – 3 (5%), stage I – 9 (15%), stage II – 23 (38.3%), stage III – 9 (15%), and stage IV –19 (31.6%). Forty (66.6%) patients received treatment at presentation for CLL. The most common regimens were chlorambucil-based, in 45%; bendamustine and rituximab, in 40%; and fludarabine-based, in 9% of cases. Forty-three cases (71.6%) progressed to Richter transformation (RT). RT developed as diffuse, large B-cell lymphoma in 40 cases and as Hodgkin lymphoma in 3 cases. The other SM were myelodysplastic syndrome –2, myelofibrosis – 1, multiple myeloma – 1, chronic myeloid leukemia – 1, basal cell carcinoma –1, carcinoma of larynx – 1, carcinoma of tongue – 1, breast cancer – 2, adenocarcinoma of lung – 2, prostate cancer – 1, renal cell carcinoma – 1, carcinoma of urinary bladder – 1, gallbladder – 1, and pancreatic cancer – 1 case. Median time to progression to SM was 39 months. Conclusion: The incidence of SM is 10.1% in our population. The most common SM is RT, which accounts for 71.6% of cases. Secondary solid tumors constitute 20% of cases without any site specification.