Growth Laws in Cancer: Implications for Radiotherapy

Abstract

Comparing both, the more conventional Gompertz tumor growth law (GL) and the "Universal" law (UL), recently proposed and applied to cancer, we have investigated the growth law's implications on various radiotherapy regimen. According to GL, the surviving tumor cell fraction could be reduced 'ad libidum', independently of the initial tumor mass, simply by increasing the number of treatments. On the contrary, if tumor growth dynamics would indeed follow the Universal scaling law, there is a lower limit of the survival fraction that cannot be reduced any further regardless of the total number of treatments. This finding can explain the so called "tumor size effect" and re-emphasizes the importance of early diagnosis as it implies that radiotherapy may be successful provided the tumor mass at treatment onset is rather small. Taken together with our previous works, implications of these findings include revisiting standard radiotherapy regimen and overall treatment protocols.

Estimating Tumor Growth Rates In Vivo

“…Guiot et al [9] used this model to fit the growth of tumor spheroids in vitro and patient data. Castorina et al [2] have investigated the implications of this growth law for radiotherapy. We mention this model here for completeness.…”

“…Many models have been proposed, but there is still no consensus about the growth patterns that solid tumors exhibit [7]. This is an important problem because an accurate model of tumor growth is needed for evaluating screening strategies [18], optimizing radiation treatment protocols [27, 2], and making decisions about patient treatment [5, 6]. …”

Production of Microalgae Biomass and Biohydrogen in Solar Bioreactors

“…The kinetics of the growth does not fit the Monod model; actually, the Gompertz model fits better with the experimental results (Fig. 5) [11,12]. In Table 1, 12 experiments in the VTR are compared in relation with the maximal cellular density, the specific growth rate and the residence time as a function of the medium (SHS or TP), the reactor diameter (70, 95 or 120 mm) and the annual season (winter or spring).…”

“…This can be reached improving different operation conditions. By instance, a better system for gas/liquid interchanges, a different air bubbling flux or adding carbon dioxide to the air, could increase the yield of the production [12]. Additionally, it is necessary to reduce costs of the culture media and new compositions should be tested using alternative sources as wastewaters.…”

Unified approach to growth and aging in biological, technical and biotechnical systems

“…Castorina et al ( [2007]) and the results clearly indicate that to understand the tumor size effect the re-growth rate for large tumor has to follow a power law Guiot et al ( [2003]) rather than the GL.…”