Changes in tumor cell proliferation and chemosensitivity after partial (up to 3/4) surgical resection were studied in C3H/HeJ mammary tumors, In all studies surgical cytoreduction stimulated tumor cell proliferation in the residual tumor, as evidenced by increases in the3H-TdR labelling index between 24 and 72 hrs after surgery. The time of maximal proliferative activity was directly related to the amount of tumor removed. In spontaneous mammary tumors, proliferative recovery after 1/2 resection could be delayed by giving dexamethasone 24 hrs after resection. The regrowth delay after surgery and various combinations of dexamethasone, vincristine, 5-FU, and cyclophosphamide, was used to assess the significance of the kinetic changes in the residual tumor for the design of adjuvant therapeutic strategies. The results indicated that the chemosensitivity of C3H/HeJ mammary tumors was substantially increased after surgical cytoreduction, and that these post-surgical changes were directly correlated with changes in tumor cell proliferative activity.
ASJC Scopus subject areas
- Cancer Research