Effects of regional lymphadenectomy and adjuvant chemotherapy on metastasis and survival in rodent tumour models

Abstract

In view of contradictory reports regarding detrimental effects of regional lymph node removal in animal tumour models, studies were performed to evaluate this controversy. In the experiments it was investigated whether removal of regional lymph nodes (R.L.N.) at any stage of tumour growth had a favourable or unfavourable effect on survival after removal of primary tumours. Removal of tumours was performed also at a stage when early metastases had taken place; this implied leaving a low tumour burden which could possibly be influenced by the host's immunological system. In three tumour models which differed in antigenicity there was no significant effect of R.L.N. removal on survival. In two tumour models which consistently showed lymph node metastases if left untreated, a significant reduction in regional recurrences was noted when regional lymph nodes were removed. In the most appropriate model of the three, the non-antigenic mammary carcinoma, a very pronounced reduction in lymph node metastases was observed when adjuvant combination chemotherapy was given after tumour removal. This was even the case at a level of drug treatment which was ineffective in prolonging survival. In this combined approach, more or less extensive surgery had no discernable effect on survival. Results are discussed in relation to relevance for the clinical management of R.L.N. in breast cancer, with special emphasis on the hazards of regional recurrence.