In a recent paper, we introduced a variant of the classical Simeoni tumor growth model, and illustrated its value in assessing tumor growth in a reproducible mouse model for mammary tumors. Our modification consisted of incorporating delay differential equations in the mathematical formulation of the Simeoni model, to represent the delay in drug action often observed under chemotherapeutic or immunotherapeutic regimens.

Glucocorticoids (GCs) are defined by their role in maintaining glucose homeostasis and natural GCs are a class of corticosteroids secreted by the adrenal cortex. Cortisol is the most important natural GC in humans. Cellular cortisol levels are regulated by the tissue-specific metabolic enzymes 11β-hydroxysteroid dehydrogenase 1 and 2 (11β-HSD 1 and 2); 11β-HSD 1 converts inactive cortisone to active cortisol, while 11β-HSD 2 has the opposite function.

Today, cancer is the second leading cause of death, with about 9.6 million deaths globally in 2018 [1]. At the end of the 19th century, Paul Ehrlich contributed a milestone to cancer research by introducing chemotherapy as a promising tumor treatment approach. Since then, cancer treatment has undergone tremendous advances, with chemotherapy still being a widely used cancer treatment method today, however, often associated with severe side effects.

Retroperitoneal lymph nodes are often the first landing site of metastatic disease in men with testicular cancer. Primary retroperitoneal lymph node dissection (RPLND) for clinical stage I NSGCT can accurately surgically stage patients who may have nodal micrometastases, and in some cases, can serve as the primary therapy when volume of metastasis is low.

The precise role of corticosteroids for treatment of coronavirus disease 2019 (COVID-19) is unclear due to lack of randomized trials.