Tumor growth

In the case of tumors, dead cells remain and form a growth known as a tumor. Cancer cells grow in the same manner. However, unlike the cells in benign tumors, cancerous cells can invade nearby tissue and spread to other parts of the body.

Autophagy could promote tumor growth in specific cancer types. Tumor intrinsic PD1 or PD-L1 could both increase autophagy through ATG13 interaction ¹⁾.

Systematic pre-radiotherapy MRI in patients with newly resected glioblastoma sometimes reveals tumor growth in the period between surgery and radiotherapy.

De Barros et al., evaluated the relation between early tumor growth and overall survival (OS) with the aim of finding predictors of regrowth.

Seventy-five patients from 25 to 84 years old (Median age 62 years) with preoperative, immediate postoperative, and preradiotherapy MRI were included. Volumetric measurements were made on each of the three MRI scans and clinical and molecular parameters were collected for each case.

Fifty-four patients (72%) had an early regrowth with a median contrast enhancement volume of 3.61 cm3-range 0.12-71.93 cm3. The median OS was 24 months in patients with no early tumor growth and 17.1 months in those with early tumor regrowth (p = 0.0024). In the population with initial complete resection (27 patients), the median OS was 25.3 months (19 patients) in those with no early tumor growth between surgery and radiotherapy compared to 16.3 months (8 patients) in those with tumor regrowth. In multivariate analysis, the initial extent of resection (p < 0.001) and the delay between postoperative MRI and preradiotherapy MRI (p < 0.001) were significant independent prognostic factors of regrowth and of poorer outcome.

They demonstrated that, in addition to the well known issue of incomplete resection, longer delays between surgery and adjuvant treatment is an independent factors of tumor regrowth and a risk factor of poorer outcomes for the patients. To overcome the delay factor, they suggest shortening the usual time between surgery and radiotherapy ²⁾.

¹⁾

Chen Z, Liu S, Xie P, Zhang B, Yu M, Yan J, Jin L, Zhang W, Zhou B, Li X, Xiao Y, Xu Y, Ye Q, Li H, Guo L. Tumor-derived PD1 and PD-L1 could promote hepatocellular carcinoma growth through autophagy induction in vitro. Biochem Biophys Res Commun. 2022 Mar 17;605:82-89. doi: 10.1016/j.bbrc.2022.03.075. Epub ahead of print. PMID: 35316767.

²⁾

De Barros A, Attal J, Roques M, Nicolau J, Sol JC, Cohen-Jonathan-Moyal E, Roux FE. Impact on survival of early tumor growth between surgery and radiotherapy in patients with de novo glioblastoma. J Neurooncol. 2019 Feb 19. doi: 10.1007/s11060-019-03120-3. [Epub ahead of print] PubMed PMID: 30783874.