Risk of myeloid neoplasms after radiotherapy among older women with localized breast cancer: A population-based study

Abstract

BackgroundThere are inconsistent and limited data regarding the risk of myeloid neoplasms (MN) among breast cancer survivors who received radiotherapy (RT) in the absence of chemotherapy. Concern about subsequent MN might influence the decision to use adjuvant RT for women with localized disease. As patients with therapy-related MN have generally poor outcomes, the presumption of subsequent MN being therapy-related could affect treatment recommendations.MethodsWe used the Surveillance, Epidemiology, and End Results (SEER)–Medicare linked database to study older women with in-situ or stage 1–3 breast cancer diagnosed 2001–2009 who received surgery. Chemotherapy and RT were ascertained using Medicare claims, and new MN diagnoses were captured using both SEER registry and Medicare claims. We excluded women who received chemotherapy for initial treatment, and censored at receipt of subsequent chemotherapy. Competing-risk survival analysis was used to assess the association between RT and risk of subsequent MN adjusting for relevant characteristics.ResultsMedian follow-up for 60,426 eligible patients was 68 months (interquartile range, 46 to 92 months), with 47.6% receiving RT. In total, 316 patients (0.52%) were diagnosed with MN; the cumulative incidence per 10,000 person-years was 10.6 vs 9.0 among RT-treated vs non-RT-treated women, respectively (p = .004); the increased risk of subsequent MN persisted in the adjusted analysis (hazard ratio = 1.36, 95% confidence interval: 1.03–1.80). The results were consistent in multiple sensitivity analyses.ConclusionsOur data suggest that RT is associated with a significant risk of subsequent MN among older breast cancer survivors, though the absolute risk increase is very small. These findings suggest the benefits of RT outweigh the risks of development of subsequent MN.

Therapy-related myelodysplastic syndromes, or are they?

“…Rather, the investigators found that radiotherapy may add to risk of marrow neoplasms when combined with chemotherapy for the treatment of breast cancer. In accordance with this result, a recent SEER based study also did not show an increased risk of t-MN in older women treated with surgery followed by radiation when compared to those who did not receive radiation [30]. Though it must be noted that the median follow up in this study was short at 48 months.…”

“…Earlier studies suggested an increased risk of leukemia in breast cancer patients treated with adjuvant radiation alone [27]. However, more recent studies suggest that radiation alone does not increase the risk of t-MN [28][29][30]. A recent analysis from the National Comprehensive Cancer Network (NCCN) Breast Cancer Outcomes Database suggests that radiation therapy alone does not significantly increase the risk of marrow neoplasms including MDS (HR=2.6; 95% CI: 0.57 to 11.9; P.21) in breast cancer patients [29].…”

Myeloid disorders after autoimmune disease

“…for localized breast cancer) with subsequent development of t-MN is more controversial. (16,21,22) Patients with AD who develop a secondary leukemia typically develop AML rather than acute lymphoblastic leukemia (ALL). An increased incidence of AML has been reported across several AD types such as rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), polymyalgia rheumatica, ankylosing spondylitis, autoimmune hemolytic anemia, systemic vasculitides, pernicious anemia, multiple sclerosis (MS), and inflammatory bowel disease (IBD).…”

Mesenchymal stem cells expressing interleukin-18 inhibit breast cancer in a mouse model

“…Breast cancer is the most common malignancy in females, accounting for ~1/3 of all types of cancer ( 1 ). Despite advances in the detection and treatment of primary and metastatic cancers, and the application of surgery, radiotherapy, chemotherapy, immunotherapy and drug combinations, the mortality rate from cancer remains high, and side effects from the aforementioned combined treatments are severe ( 2 ). Therefore, identifying a more effective and less dangerous therapy for cancer is imperative.…”