Comparative analysis of the inherent radiosensitivity of ovarian carcinoma

Our plain-English summary of Comparative analysis of the inherent radiosensitivity of ovarian carcinoma, by J. Rotmensch, M.A. Beckett, P. Toohill, et al (Gynecologic and Obstetric Investigation, 1989).

The study

• Authors: J. Rotmensch, M.A. Beckett, P. Toohill, R.R. Weichselbaum, J.L. Schwartz
• Journal: Gynecologic and Obstetric Investigation
• Published: 1989;28(4):215-8
• Read it: PubMed · Publisher

Abstract

Success or failure of radiation therapy in patients with ovarian carcinoma is due to the inherent radiosensitivity of both the tumor cell and the surrounding normal tissues. The D0 value were 1.65 Gy for benign mesothelium, 1.50 for the ovarian carcinoma, and 1.45 Gy for the fibroblasts. The ovarian carcinoma cells had a similar n value (1.7) to the mesothelial (n = 2.5) or fibroblast (n = 1.2) cells. Similarly, the 24-hour potentially lethal damage repair ratios were 2.26 for the tumor cells and 2.2 for the benign cells. The kinetics of the induction and repair of DNA strand breaks caused by X-ray irradiation were similar for the three cell types.

In plain English

This laboratory study compared how sensitive ovarian cancer cells and non-cancerous cells were to X-rays. The ovarian cancer cells and benign mesothelial (lining) cells were grown from abdominal fluid (ascites) of one 48-year-old woman with advanced papillary serous cystadenocarcinoma. Human fibroblasts from an established line (line 1522) were used for comparison. D0, a measure of how much radiation it takes to kill cells, was 1.50 Gy for ovarian carcinoma cells, 1.65 Gy for mesothelial cells and 1.45 Gy for fibroblasts. A second survival measure, the n value, was 1.7, 2.5 and 1.2 respectively; the authors reported these as similar (p = 0.15). For recovery from potentially lethal damage at 24 hours, the Results gave 2.26-fold in tumor cells and fibroblasts, but the abstract gives 2.2 for benign cells and the Discussion 2.2-fold for both. Nearly all DNA strand breaks caused by 4 Gy were repaired within 1 hour, and the authors reported no significant differences between cell types. The authors concluded that, if damage to normal tissue can be minimized, this tumor should respond to radiation therapy. The study did not involve asbestos.

We wrote this plain-English summary from the full article with the help of AI, and a second AI model checked each sentence against the article. It is not the authors' wording; the abstract and the article are their own account.

What the study did and found

• Design: Laboratory (cell culture) radiobiology study comparing an early-passage human ovarian carcinoma cell line with benign cells
• Who was studied: Ovarian carcinoma cells and benign mesothelial cells grown from the ascites of one 48-year-old woman with stage IV, grade 2 papillary serous cystadenocarcinoma whose disease had not responded to multiagent chemotherapy. Human fibroblasts (line 1522) from an established cell line were used for comparison. The work was done at the University of Chicago.
• Exposure: X-ray irradiation of cultured cells with a 250-kV machine at 0.8 Gy/min. DNA strand breaks were measured after 4 Gy, and recovery from potentially lethal damage after 5.7 or 9 Gy. No asbestos exposure was studied.
• Main results:
  • Radiation sensitivity (D0) was 1.65 Gy for mesothelial cells, 1.50 Gy for ovarian carcinoma cells and 1.45 Gy for fibroblasts. The authors described the ovarian cancer cells' radiosensitivity as similar to that of the benign cells.
  • The n values were 1.7 for ovarian carcinoma cells, 2.5 for mesothelial cells and 1.2 for fibroblasts, reported as similar (p = 0.15)
  • The Results section reported a 2.26-fold increased ability to recover from potentially lethal radiation damage at 24 hours in both tumor cells and fibroblasts
  • The article's abstract instead gives potentially lethal damage repair ratios of 2.26 for the tumor cells and 2.2 for the benign cells
  • The Discussion gives a 2.2-fold ability to repair and recover from radiation at 24 hours for both the ovarian carcinoma cells and the fibroblasts
  • Initial single-strand DNA breaks after 4 Gy were 5.2 Gy-equivalents in ovarian cells, 3.9 in mesothelial cells and 5.4 in fibroblasts
  • Initial double-strand breaks were 128.9 Gy-equivalents for ovarian carcinoma cells, 124.7 for mesothelial cells and 121.8 for fibroblasts (p = 0.18)
  • After 1 hour nearly all breaks had been repaired. Remaining single-strand breaks were 0.4 Gy-equivalents in ovarian carcinoma cells, 0.8 in mesothelial cells and 0.2 in fibroblasts.
  • The time to repair half the induced breaks was 9.75 min for ovarian carcinoma cells, 12 min for benign mesothelial cells and 6.75 min for fibroblasts
  • The authors found no significant differences in the rate of repair or in initial or final DNA single- or double-strand break frequencies
• The authors' conclusion: The authors concluded that the radiosensitivities of normal and malignant cells were similar, and that if normal-tissue toxicity can be minimized this tumor should respond to radiation therapy. They added that radiocurability depends on multiple parameters, including the radiosensitivity of surrounding tissues.

Topics

The National Library of Medicine indexes this study under subjects our site covers: Ovarian cancer.

Medical terms in this study, explained in our Lexicon: Carcinoma, Mesothelium, Fibroblast.

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