Risk for developing myelodysplastic syndromes in prostate cancer patients definitively treated with radiation

Epidemiologic outlook of therapy-related myeloid neoplasms and selection of high-risk patients: A Korean nationwide study

BACKGROUND

Although a considerable proportion of patients with cancer receive chemotherapy (CT) or radiotherapy (RT), only a very few patients eventually develop therapy-related myeloid neoplasms (t-MNs).

METHODS

To identify subsets of cancer patients who have substantially elevated risk of developing t-MNs. Incidences and risks of t-MNs after contemporary CT or RT in patients newly diagnosed major cancers during 2009-2013 were analyzed. By merging two Korean nationwide health care big data sets, patients were selected and observed on follow-up to until t-MN development or December 2019.

RESULTS

Among 250,155 patients, 555 (0.22%) were diagnosed with t-MNs with a standard incidence ratio (SIR) of 3.40 (95% CI, 3.13-3.70). Patients had bone/joint cancers (SIR, 94.25; 95% CI, 50.71-137.80) and a remarkably high SIR for t-MN development. Patients receiving both CT and RT had the highest SIR (4.64; 95% CI, 4.08-5.20), followed by those receiving CT only (SIR, 3.30; 95% CI, 2.89-3.70). Contrarily, RT alone did not increase t-MN risk (SIR, 1.16; 95% CI, 0.76-1.56). More exposure to leukemogenic agents resulted in the higher t-MNs development.

CONCLUSIONS

The increased risk of developing acute myeloid leukemia or myelodysplastic syndrome after CT and/or RT was confirmed and subsets with substantially elevated risk for developing t-MNs were found. Such patients would be suitable for a prospective cohort for investigating t-MN pathogenesis by time series analyses.

Therapy-related myeloid neoplasms with normal karyotype show distinct genomic and clinical characteristics compared to their counterparts with abnormal karyotype

Therapy-related myeloid neoplasms (t-MNs) are a complication of treatment with cytotoxic chemotherapy and/or radiation therapy. The majority of t-MNs show chromosomal abnormalities associated with myelodysplastic syndrome (MDS) or KMT2A rearrangements and are characterized by poor clinical outcomes. A small but substantial subset of patients have normal karyotype (NK) and their clinical characteristics and mutational profiles are not well studied. We retrospectively studied patients diagnosed with t-MN at three institutions and compared the mutational profile and survival data between t-MNs with NK and t-MNs with abnormal karyotype (AK). A total of 204 patients with t-MN were identified including 158 with AK and 46 with NK. NK t-MNs, compared to AK, were enriched for mutations in TET2 (p < 0.0001), NPM1 (p < 0.0001), ASXL1 (p = 0.0003), SRSF2 (p < 0.0001), RUNX1 (p = 0.0336) and STAG2 (p = 0.0099) and showed a significantly lower frequency of TP53 mutations (p < 0.0001). Overall survival (OS) was significantly lower in AK t-MNs as compared to NK cases (p = 0.0094). In our study, NK t-MNs showed a significantly better OS, a higher prevalence of MN-associated mutations and a lower frequency of TP53 mutations compared to their AK counterparts. The distinct clinical and mutational profile of NK t-MNs merits a separate classification.

Secondary myelodysplastic syndromes identified via next-generation sequencing in a non-small cell lung cancer patient

BACKGROUND

Myelodysplastic syndrome (MDS) is a group of clonal disorders characterized by ineffective and dysplastic hematopoiesis in the bone marrow with a high risk of progression to leukemia. Many studies have demonstrated that chemo-radiotherapy for cancer patients and exposure to certain chemicals may increase the risk of secondary MDS, which is characterized by specific chromosomal abnormalities and genomic alterations. Since next-generation sequencing (NGS) has been widely used for the diagnosis of cancer patients, advanced analysis of the sequencing data may provide supplementary information for secondary MDS.

CASE PRESENTATION

A male patient with non-small cell lung cancer (NSCLC) and bone metastases has presented distal obstructive inflammation, the enlargement of the left hilar, mediastinal lymph node metastases, and multiple bone metastases. This patient has undergone long-term exposures to certain chemicals. Moreover, the deletion of chromosome 7 and 5q is detected in his peripheral blood sequencing, indicating secondary MDS, subsequently confirmed by bone marrow examination.

CONCLUSION

In this case, an NSCLC patient was diagnosed with secondary MDS via NGS analysis, indicating that the NGS analysis may serve as supplementary for diagnosis of secondary MDS and provide useful information of therapeutic regimens for subsequent-line treatment of EGFR-mutated lung cancer. To the best of our knowledge, this is the first report of acquired MDS in a lung adenocarcinoma patient.

Risk of subsequent myeloid neoplasms after radiotherapy treatment for a solid cancer among adults in the United States, 2000-2014

Although increased risk of acute myeloid leukemia (AML) has been observed after chemotherapy and radiotherapy, less is known about radiotherapy-related risks of specific AML subtypes and other specific myeloid neoplasms. We used the US population-based cancer registry data to evaluate risk of myeloid neoplasms among three cohorts of cancer survivors initially treated with radiotherapy only. We included 1-year survivors of first primary thyroid (radioiodine only, stages I-IV; N = 49 879), prostate (excluding stage IV; N = 237 439), or uterine corpus cancers (stage I-II; N = 16 208) diagnosed during 2000-2013. We calculated standardized incidence ratios (SIRs) and excess absolute risks (EARs). Thyroid cancer survivors had significantly elevated risks of total AML (SIR = 2.77, 95% CI: 1.99-3.76), AML with cytogenetic abnormalities (SIR = 3.90, 95% CI: 1.57-8.04), AML with myelodysplasia-related changes (SIR = 2.87, 95% CI: 1.05-6.25), and BCR-ABL1-positive chronic myelogenous leukemia (CML) (SIR = 5.38, 95% CI: 2.58-9.89). Irradiated prostate and uterine corpus cancer survivors were at elevated risk for total AML (SIR = 1.14, 95% CI: 1.03-1.27 and SIR = 1.77, 95% CI: 1.01-2.87, respectively), AML with cytogenetic abnormalities (SIR = 2.52, 95% CI: 1.84-3.37 and SIR = 7.21, 95% CI: 2.34-16.83, respectively), and acute promyelocytic leukemia (SIR = 3.20, 95% CI: 2.20-4.49 and SIR = 8.88, 95% CI: 2.42-22.73, respectively). In addition, prostate cancer survivors were at increased risk of BCR-ABL1-positive CML (SIR = 2.11, 95% CI: 1.52-2.85). Our findings support the importance of diagnostic precision in myeloid neoplasm classification since susceptibility following radiotherapy may vary by myeloid neoplasm subtype, thereby informing risk/benefit discussions in first primary cancer treatment.

Therapy-related myeloid neoplasms: when genetics and environment collide

Therapy-related myeloid neoplasms (t-MN) arise as a late effect of chemotherapy and/or radiation administered for a primary condition, typically a malignant disease, solid organ transplant or autoimmune disease. Survival is measured in months, not years, making t-MN one of the most aggressive and lethal cancers. In this Review, we discuss recent developments that reframe our understanding of the genetic and environmental aetiology of t-MN. Emerging data are illuminating who is at highest risk of developing t-MN, why t-MN are chemoresistant and how we may use this information to treat and ultimately prevent this lethal disease.

Myelodysplastic Syndromes and Acute Myeloid Leukemia After Radiotherapy for Prostate Cancer: A Population-Based Study

BACKGROUND

To understand the impact of radiotherapy on the development of myelodysplastic syndromes (MDS) and acute myeloid leukemia (AML) among elderly prostate cancer patients.

METHODS

We performed a retrospective cohort study of elderly prostate cancer patients diagnosed during 1999-2011 by using the National Cancer Institute's Surveillance, Epidemiology and End Results-Medicare linked database. Competing risk analyses adjusting for patient characteristics were conducted to assess the impact of radiotherapy on the development of subsequent MDS/AML, compared with surgery.

RESULTS

Of 32,112 prostate cancer patients, 14,672 underwent radiotherapy, and 17,440 received surgery only. The median follow-up was 4.68 years. A total of 157 (0.47%) prostate cancer patients developed subsequent MDS or AML, and the median time to develop MDS/AML was 3.30 (range: 0.16-9.48) years. Compared with prostate cancer patients who received surgery only, patients who underwent radiotherapy had a significantly increased risk of developing MDS/AML (hazard ratio [HR] =1.51, 95% confidence interval [CI]: 1.07-2.13). When radiotherapy was further categorized by modalities (brachytherapy, conventional conformal radiotherapy, and intensity-modulated radiotherapy [IMRT]), increased risk of second MDS/AML was only observed in the IMRT group (HR = 1.66, 95% CI: 1.09-2.54).

CONCLUSIONS

Our findings suggest that radiotherapy for prostate cancer increases the risk of MDS/AML, and the impact may differ by modality. Additional studies with longer follow-up are needed to further clarify the role of radiotherapy in the development of subsequent myeloid malignancies. A better understanding may help patients, physicians, and other stakeholders make more informed treatment decisions. Prostate 77:437-445, 2017. © 2016 Wiley Periodicals, Inc.

Therapy-related myelodysplastic syndromes, or are they?

The incidence of therapy-related myelodysplastic syndromes (t-MDS) is increasing as the number of cancer survivors is increasing. While t-MDS is currently defined descriptively by prior receipt of chemotherapy and/or radiotherapy, some forms of MDS that occur post localized radiation monotherapy, biologically and clinically resemble de novo (d)-MDS more than t-MDS, and therefore may not be truly therapy-related. Although patients with t-MDS, as a group, fare worse than patients with d-MDS, a variation in individual outcomes of patients with t-MDS has increasingly been appreciated. As such, accurate risk stratification is important for counseling of patients and for clinical decision making. Most of the current clinical tools used for prognostication in t-MDS were developed for d-MDS and were not specifically validated in patients with t-MDS. The management of patients with t-MDS remains challenging, highlighting the importance of developing effective prevention strategies as well as newer, targeted, and rationally-designed therapeutic interventions.

Defining AML and MDS second cancer risk dynamics after diagnoses of first cancers treated or not with radiation

Risks of acute myeloid leukemia (AML) and/or myelodysplastic syndromes (MDS) are known to increase after cancer treatments. Their rise-and-fall dynamics and their associations with radiation have, however, not been fully characterized. To improve risk definition we developed SEERaBomb R software for Surveillance, Epidemiology and End Results second cancer analyses. Resulting high-resolution relative risk (RR) time courses were compared, where possible, to results of A-bomb survivor analyses. We found: (1) persons with prostate cancer receiving radiation therapy have increased RR of AML and MDS that peak in 1.5-2.5 years; (2) persons with non-Hodgkin lymphoma (NHL), lung and breast first cancers have the highest RR for AML and MDS over the next 1-12 years. These increased RR are radiation specific for lung and breast cancer but not for NHL; (3) AML latencies were brief compared to those of A-bomb survivors; and (4) there was a marked excess risk of acute promyelocytic leukemia in persons receiving radiation therapy. Knowing the type of first cancer, if it was treated with radiation, the interval from first cancer diagnosis to developing AML or MDS, and the type of AML, can improve estimates of whether AML or MDS cases developing in this setting are due to background versus other processes.

Incidence and Burden of the Myelodysplastic Syndromes

Since 2001, cases of myelodysplastic syndromes (MDSs) have been tracked by cancer registries. Examining registry data in the USA, the reported age-adjusted incidence of MDS per 100,000 was 3.3 per year for 2001-2003 and 4.9 per year for 2007-2011, with increases likely a result of growing awareness of reporting requirements. However, active case-finding methods repeatedly demonstrate that population-based registries have underestimated the incidence of MDS due to underreporting and underdiagnosis. Using keyword search strategies of electronic pathology reports or other novel case capture methods, the true incidence of MDS has been estimated between 5.3 and 13.1 per 100,000. Using Medicare billing claims data, the incidence of MDS per 100,000 in patients aged ≥65 years has been estimated between 75 and 162. MDS prevalence is estimated to be 60,000 and -170,000 in the USA and projected to grow. Epidemiologic data can help estimate the burden of MDS and expose unmet clinical needs. For example, patients with MDS receiving transfusions had significantly higher reported health care costs versus those that did not (3-year mean of $88,824 vs $29,519). Epidemiologic data also revealed that most MDS patients receiving transfusions do not receive active therapies, despite strong evidence that hypomethylating agents and lenalidomide significantly reduce transfusion burden. Other unmet needs identified by epidemiologic studies include high need for treatment options after failing first-line therapy and shared decision making by older MDS patients.

Radiotherapy- and chemotherapy-induced myelodysplasia syndrome: a nationwide population-based nested case-control study

This study explored which kinds of cancer are related to a higher incidence of subsequent myelodysplastic syndrome (MDS) after radiotherapy (RT) and chemotherapy (CT).We performed a nested case-control study by using data from the Taiwanese National Health Insurance (NHI) system. The case group included cancer patients who developed MDS. For the control group, 4 cancer patients without MDS were frequency-matched with each MDS case by age, sex, year of cancer diagnosis, and MDS index year. A multivariable logistic regression analysis was conducted, and odds ratios (ORs) and 95% confidence intervals (CIs) were estimated.Overall, cancer patients who received RT or CT exhibited secondary MDS more frequently than did those who did not (RT: OR = 1.53; 95% CI = 1.33-1.77; CT: OR = 1.51; 95% CI = 1.25-1.82). Analysis by cancer site showed that RT increased the risk of MDS for patients with stomach, colorectal, liver, breast, endometrial, prostate, and kidney cancers. By contrast, CT was more likely to increase the risk of MDS for patients with lung, endometrial, and cervical cancers. Further analysis revealed that RT and CT seemed to have a positive interaction. The major limitation of this study was the lack of certain essential data in the NHI Research Database, such as data regarding cancer stage and treatment dose details.This population-based nested case-control study determined that RT and CT predisposed patients in Taiwan to the development of MDS. This effect was more prominent when both modalities were used.

Myeloid neoplasms after breast cancer: "therapy-related" not an independent poor prognostic factor

Two hundred and thirty-five consecutive patients presenting to a single center with acute myeloid leukemia (AML) or myelodysplastic syndrome (MDS) after breast cancer treatment were compared with matched patients with de novo AML or MDS. There was no significant difference in median overall survival (OS) times between patients with therapy-related AML and those with de novo AML (8.7 months vs.10.2 months; p = 0.17). Patients with therapy-related MDS had slightly lower median baseline platelet counts and a higher frequency of poor cytogenetics than those with de novo MDS, but the two groups had similar OS times (13.6 months vs. 18.9 months; p = 0.06). Multivariate analysis revealed that cytogenetic risk, baseline white blood cell count, age and performance status were predictive for OS time in AML and that cytogenetic risk and performance status were predictive for OS time in MDS. Having therapy-related disease is not an independent risk factor in patients with myeloid neoplasms and with a history of breast cancer. Clinical trials should be designed to serve both populations.

Allogeneic hematopoietic cell transplantation for myelodysplastic syndromes: lingering uncertainties and emerging possibilities

The landscape of transplantation in myelodysplastic syndrome (MDS) has evolved rapidly in the last decade, driven mostly by advances in patient selection through better risk stratification, increasing age of allogeneic recipients, introduction of reduced-intensity conditioning regimens, increased availability of unrelated donors, new donor sources, and improvements in transplant technology and supportive care. Despite these advances, several issues, mostly centering on approaches to improve post-transplant survival while minimizing transplant-related mortality, continue to present significant challenges. Advances in understanding the molecular pathogenesis of MDS have made it feasible to construct clinically useful risk models that integrate prognostic genes with conventional risk parameters for better selection of patients likely to benefit from hematopoietic cell transplantation. Simultaneous research efforts in several areas, including comorbidity assessment, novel preparative regimens, optimal pretransplant cytoreductive strategy, and post-transplantation therapies, are expected to improve long-term disease-free survival and quality of life.