Tumor growth

By the time a tumor is 5 mm in diameter it has undergone approximately 20 doubling times and represents almost 10th to the 8th cells.

A 10 mm mass has approximately 10th to the 9th cells.

A 30 mm mass has approximately 2.7 x 10 to 10th cells.

Death usually results when a tumor burden reaches 10 to the 12th cells.

Neovascularization required for a tumor to grow beyond 1-3mm.

Production rate of new cells determined by number of cells in the growth fraction and length of their cell cycle.

Net growth rate of a tumor must account for cell loss which is due to differentiation, degeneration, necrosis, apoptosis, resorption by immunologic cells, exfoliation and metastases.

Unlike normal tissues the production of cells in a tumor exceeds cell loss.

Studies in animal models suggest surgery increases the number of circulating tumor cells and can potentiate the growth of metastatic disease.

Metastatic tumor growth correlates with a reduction and angiogenesis inhibitors following removal of the primary tumor.

Resection of a primary tumor in the presence of metastatic disease will enhance the growth of distant lesions (Gunduz N et al, Fisher B et al).

Protein factor is synthesized by primary tumors restrict tumor growth at metastatic sites, so that such lesions grow once the primary lesion is resected (Fisher B et al, Folkman J).

Surgery enhances the production of oncogenic growth factors such as transforming growth factor alpha which can increase tumor growth.

Tumor growth is supported by metabolic activities, supported by oncogene driven changes that allow cancer cells to take up nutrients, build macromolecules, and proliferate.
Nutrient deprivation is an effective cancer therapy: ALL requires exogenous amino acid asparagine, and depleting L-asparagine gene from the blood with the use of L-aspariginase is a key component of therapy.
Glucose and glutamine are involved in cancer cell metabolism, and both are abundant in the bloodstream and are taken up by cancer cells and is enhanced through oncogenic signaling.

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