This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Ritzi, E. M. Articles by Stolfi, R. L. Search for Related Content PubMed PubMed Citation Articles by Ritzi, E. M. Articles by Stolfi, R. L.

Plasma Levels of a Viral Protein during Adjuvant Treatment: Reflection of Murine Mammary Tumor Status and Therapeutic Effect¹

Texas Tech University Health Sciences Center, Lubbock, Texas 79430 [E. R.], and The Catholic Medical Center of Brooklyn and Queens, Woodhaven, New York 11421 [D. M., R. S.]

The mouse mammary tumor and its associated virus, mouse mammary tumor virus, were chosen to test the possibility of using plasma levels of a M_r 52,000 viral glycoprotein (gp52) as a means for monitoring changes in tumor status during surgical adjuvant cyclophosphamide:doxorubicin (Adriamycin):5-fluorouracil treatment. Analysis of tumor recurrence and plasma gp52 concentrations during the postoperative period demonstrated that both parameters were significantly decreased in the group receiving cyclophosphamide:doxorubicin:5-fluorouracil treatment. This observation suggests that plasma gp52 levels may be a useful alternative measure of therapeutic effect during surgical adjuvant treatment. A retrospective analysis of gp52 plasma levels and tumor status of individuals during treatment has revealed the following associations. (a) An early sharp postsurgical elevation in plasma gp52 level was associated with subsequent death of treated animals. (b) Maintenance of postsurgical gp52 levels at a low level (4.2 ng/ml) during and after treatment was characteristic of all tumor-free survivors. (c) A gradual rise in plasma gp52 level accompanied CAF-delayed tumor recurrence. gp52 levels increased in all treated animals 2 wk prior to detectable tumor regrowths, resulting in a statistically significant increase in mean gp52 level (2.2 to 5.4 ng/ml). However, the magnitude of this increase was small for the majority of animals with tumor regrowths, and greater, more definitive elevations in plasma gp52 levels were only detected at the time of frank tumor recurrence. In addition, comparisons of early mean gp52 levels (8 to 10 days after surgery) for controls and for animals receiving various forms of alternative treatment have indicated that differences in gp52 levels reflect subsequent differences in recurrence rates.

The present data, obtained during surgical adjuvant treatment of BALB/c x DBA/8 F₁ mice and viewed in a retrospective fashion, demonstrate that plasma gp52 concentrations reflected therapeutic effects.

¹ This study was supported by USPHS Grants CA 28305-01, 1P01 CA 25842, and CA 38335-01 and Contract CP 71016; Grant VC-283 of the American Cancer Society; and the Chemotherapy Foundation, New York, NY.

² To whom requests for reprints should be addressed, at Texas Tech University Health Sciences Center, Department of Microbiology, Lubbock, TX 79430.

Received 6/11/85. Revised 11/19/85. Revised 2/ 3/86. Accepted 3/ 5/86.