Combined chemotherapy and cryosurgery for oral cancer.
The inadequacies of traditional methods for control of advanced oral carcinomas at their sites of origin prompted evaluation of combined chemotherapy and cryosurgery in seventy-three patients treated since 1969. Our experience with thirty-nine unlikely candidates for salvage by other therapy is the subject of this report. The majority had recurrent disease after other therapy. The observed morbidity potential of combined chemotherapy and cryosurgery with earlier experience led to abbreviations and refinements of method that are described and consist mainly of the following. (1) A two day postcryosurgical infusion (intra-arterial) of 5-fluorouracil (1 gm per twenty-four hours, or less) in lieu of methotrexate, the systemic toxicity and therapeutic efficacy of which seem less predictable with cryosurgery. (2) Electrosurgical subtotal tumor resection at the time of initial cryosurgery to reduce swelling and magnitude of in situ tissue slough. (3) Use of a flexible copper mesh cryoprobe that enhances feasibility of in-depth wide field cryosurgery. (4) Systematic use of multiple marginal wound biopsies as a principal guide to repetitive cryosurgery or other therapeutic adjunct selection. A special warning that available toxicologic data for independent drug therapy may not be applicable in patients after cryosurgery is given. Current experience indicates that negative biopsy after such combined therapy may be 85 per cent reliable in foretelling lesion outcome. Among the thirty-nine patients reported, twenty remain alive from six months to six years, only two of whom have clinically evident recurrent disease. If such could be reasonably accomplished, comparative evaluation of single methods should precede attempts to combine two or more modes of therapy. Since neither chemotherapy nor cryosurgery, as known today, can eliminate nodal metastases, each must be regarded as potentially adjunctive to other methods for achieving the ultimate goal of a cancer-free patient. It is within this context that combined chemotherapy and cryosurgery have been applied to unfavorable candidates for cure with seemingly worthwhile gains. Potential applicability for patients with less formidable stages of disease cannot be extrapolated from this experience. Large scale controlled clinical trials must provide the ultimately conclusive test of efficacy for such combined forms of therapy before decisive revision of traditional standards of practice might result.