Minimizing hematological toxicity in the management of anal cancer patients

ABSTRACT Introduction: Hematological toxicity (HT) remains a major side effect of anal cancer (AC) treatment that can lead to unplanned treatment breaks and may affect clinical outcome. Areas covered: This review paper analyses the predictive factors related to HT and methods to minimize HT. Expert commentary: The destruction of red bone marrow (BM) stem cells are responsible for acute HT. BM damage is correlated with radiation dose and volume of BM irradiated. Functional imaging has been used to precisely quantify specific regions of active Pelvic BM . Studies using LKB modelling confirmed that PBM and LSBM act like parallel organs with a consistent volume effect in the development of HT. BM dose-volume constraints are recommended to minimise HT. BM-sparing IMRT plans incorporating active BM sites as avoidance structures resulted in significant reduction of dose to PBM without compromising target coverage and decreased the dose delivered to the functional BM volume. The increased incidence of HT is attributed more to MMC rather than IMRT. A single dose of MMC could be considered to minimize the incidence of HT. Clinical research should focus on newer more potent and potentially less toxic systemic agents to be used in combination with radiation.