11. Bone marrow transplantation

Allo-SCT has also been demonstrated to be beneficial in treating isolated MS. Consequently, many investigators/clinicians considered allo-SCT as a primary line treatment following remission in MS patients [21, 43]. However, in a retrospective study, Chevallier et al. have showed that there is no difference in 5-year survival rate in patients with isolated or MS with leukemia when treated with allo-SCT [43]. In both the cases, the average survival was 48% for 5-year survival. In a different study, Pileri et al. showed that MS patients receiving transplantation demonstrated a better overall survival rate (70%), than patients who did not receive transplantation (0%) as a part of the treatment plan [21]. In subgroup analysis, transplantation did not display any biasness depending on age, tumor site, timing of diagnosis etc. [21].

Taken together, these reports do suggest that transplantation should be considered as a part of the consolidation therapy following remission in both isolated and leukemic MS in adult and pediatric patients. However, one should be cautious as there are reports of manifestation of MS postallo-SCT, most likely due to reduced graft-versus-leukemia (GVL) state at extramedullary sites [25].

At present, there is not enough data in the field to make an informed choice for the best course of treatment for different variants of MS. Based on the existing data, it is reasonable to consider systemic chemotherapy as the best course of action, in association with radiotherapy and allo-SCT depending on the bone marrow involvement. Given the fact that most of the reports are isolated, single center analysis with small patient pool, it is not possible to develop a consensus therapeutic regimen. To achieve such MS specific therapy, large multicenter collaboration and development of prospective clinical trials is imperative.
