SURVIVORS of blood or bone marrow transplants have an increased risk of subsequent malignant neoplasms in the gastrointestinal (GI) tract. The results of a cohort study suggest that the risk vary with both cancer type and therapeutic exposures. With the number of long-term blood or marrow transplant survivors set to exceed 500,000 by 2030, the population is at an increased risk of subsequent malignant neoplasms (SMN).
SMNs are the leading cause of non-relapse mortality in long-term survivors. Due to their often-aggressive nature, cancers of the GI tract are of particular interest. Therefore, researchers at the University of Alabama at Birmingham (UAB) School of Medicine, utilised the Bone or Marrow Transplant Survivor Study to identify clinical, therapeutic, and demographic factors associated with SMNs in the GI tract among transplant survivors.
A total of 6,710 individuals were included in the study (median age: 46 years; range: 0–78; male: 58.4%; White: 73.2%), all of whom had survived at least 2 years after allogeneic (48.7%) or autologous (51.3%) transplants. All transplants were performed between 1974 and 2014 at City of Hope, University of Minnesota, Minneapolis, USA, or UAB. SMNs in the GI tract were self-reported before being confirmed via medical records and/or pathology reports. Results were reported as standardised incidence ratios, allowing the researchers to assess the excess risk for SMNs in the GI tract compared with the general population.
The total person-years of follow-up was 62,479, during which 148 patients developed SMNs in the GI tract. The standardised incidence ratios for specific SMNs ranged from 2.1 for colorectal cancer (95% confidence interval [CI]: 1.6–2.8) to 7.8 for oesophageal cancer (95% CI: 5.0–11.6). Allogenic bone marrow transplant recipients with chronic graft-versus-host disease had an increased risk of oesophageal cancer (sub-distribution hazard ratio [SHR]: 9.9; 95% CI: 3.2–30.5). Finally, the risk of developing liver cancer was increased in transplant patients treated with etoposide (SHR: 2.0; 95% CI: 1.1–3.5) and anthracycline (SHR: 5.4; 95% CI: 1.3–23.4) when compared to patients who were not exposed to either treatment.
Due to the growing number of transplant survivors, additional screening should be established in order to best evaluate long-term risk, advise the research team. An awareness of subgroups of survivors would also permit the exploration of individualised screening for specific types of SMNs in the GI tract.