Evaluation of Lithium Efficacy Against Chemotherapy Induced Neutropenia in Breast Cancer Patients

Introduction:

Cytotoxic chemotherapy predictably suppresses the hematopoietic system, impairing host protective mechanisms. Neutropenia is the most serious hematologic toxicity of cancer chemotherapy, often limiting the doses of chemotherapy that can be tolerated. The degree and duration of the neutropenia determine the risk of infection. The Common Toxicity Criteria of the National Cancer Institute is the most commonly used scale for grading the severity of the cytopenias associated with cancer chemotherapy; it delineates neutropenia into 4 grades. Chemotherapy predisposes patients with cancer to infections both by suppressing the production of neutrophils and by cytotoxic effects on the cells that line the alimentary tract. Neutrophils are the first line of defence against infection as the first cellular component of the inflammatory response and a key component of innate immunity. Neutropenia blunts the inflammatory response to nascent infections, allowing bacterial multiplication and invasion. Because neutropenia reduces the signs and symptoms of infection, patients with neutropenia often may present with fever as the only sign of infection. In this setting, patients with fever and neutropenia, or febrile neutropenia (FN), must be treated aggressively, typically with intravenous antibiotics and hospitalization, because of the risk of death from rapidly spreading infection. The availability of hematopoietic growth factors and improvements in antibiotic therapy have changed greatly how clinicians approach the management of neutropenia, yet this complication remains a central concern in the delivery of cancer chemotherapy.

Lithium carbonate continues to be the most useful agent available for the prophylaxis and treatment of bipolar illness. Lithium augmentation of antidepressants is useful in the treatment of resistant unipolar depression. Its utility in other psychiatric disorders such as schizophrenia, alcoholism, or aggressive behaviour is documented only when a significant affective component exists. Hematologic changes have been associated with lithium Unexplained increases in white blood cell (WBC) counts have occurred in psychiatric patients treated with lithium. This leukocytosis occurs within 1 week of treatment and is reversible. It is unrelated to age, sex, or diagnosis. Although serum levels above 0.5 milliequivalent/L are required for the effect, there is no proportional response to dose. In 1998, Ballin et al prospectively examined eight adult patients with bipolar disorder to find whether lithium carbonate increased their peripheral blood cluster of differentiation 34 (CD34) hematopoietic stem cells (HSC). The administration of lithium salts to haematologically normal subjects is associated with increased marrow neutrophil production and enhanced release of granulocyte colony stimulating factor (G-CSF) in vitro, followed by peripheral blood neutrophilia.The unsaturated vitamin B12-binding capacity, an indirect assessment of the total-body granulocyte pool, is elevated in patients taking lithium for manic-depressive psychosis. In man, oral lithium carbonate raises urinary levels of G-CSF and augments production of G-CSF by peripheral blood mononucleated cell. Moreover, when Levitt and Quesenberry studied the effects of adding lithium to a murine bone marrow liquid culture system, lithium substantially increased the number of granulocyte-committed progenitor cells and pluripotential stem cells. Lithium therefore seems to have at least two distinct actions in haematopoiesis: It enhances the production of G-CSF, and it directly stimulates the proliferation of pluripotential stem cells. In 1978, Stein et al. first formally showed that lithium-induced granulocytosis was not merely a redistribution of granulocytes that are marginated or are in the marrow reserves, supporting the hypothesis of increased granulocyte production. Lithium also affects cytokines that involved in mobilization of neutrophils from bone marrow to blood through inhibition of Glycogen synthase kinase 3 (GSK-3) function, thereby indirectly increasing the attractive CXCL12 gradient toward a hypoxic marrow trophic niche, where HSCs can thrive. This is reflected by increased marrow trophic niche function: peripheral neutrophilia, increased platelets, and increased CD34+ counts.

Additionally, lithium has anticancer activity and neuroprotective properties. One piece of experimental evidence for lithium's potential as a cancer therapy is that inhibition of GSK3 was observed to inhibit prostate cancer cell proliferation. With respect to colorectal cancer, it has been found that lithium inhibits proliferation of a colorectal cancer cell line. Phosphatase and tensin homolog (PTEN) overexpression and lithium administration were shown to cooperatively inhibit proliferation of colorectal cancer cells. Because lithium therapy is systemic rather than topical or local, it follows that lithium might inhibit metastasis. Evidence that this is the case for colon cancer comes from observation of inhibition of metastasis-inducing factors by lithium and by observation on reduced metastasis in model animals given lithium therapy. Autophagy is a key cellular process in the inhibition of cancer. Lithium has been shown to induce autophagy, due to its inhibition of inositol monophosphatase.

For these issues that mentioned above about neutropenia and lithium ability to reduce the incidence of neutropenia in patient taking chemotherapy without needing to highly costing recombinant granulocyte colony stimulating factors that Egyptian patient can't afford or using the antibiotic as a prophylactic agent that will result in resistance. we want to use lithium to attenuate neutropenia induced chemotherapy. Also because of the anti-cancer activity and neuroprotective properties of lithium that mentioned above we hypothesis that lithium will not conflict with chemotherapy treatment but will help to gain the maximum benefit of chemotherapy and minimize the side effects.