Clinico-pathological and treatment related factors influencing survival inparotid cancer

One hundred and three patients with primary parotid cancer treated surgical ly at the Christie Hospital, Manchester (1952-1992), were analysed to asses s the influence on survival of prognostic and treatment-related factors. Th irty-seven patients were treated by surgery alone (SG), 66 received post-op erative radiation (SG+RT). Median follow-up was 12 years; minimum 5 years. The 10-year disease-specific survival rates for stage I, II and III/IV were 96%, 61% and 17% respectively (P < 0.0001). The various histological types segregated into three survival patterns: low-, intermediate-and high-grade with 10-year survival rates of 93%, 41% and 50% respectively (P < 0.0001). On multivariate analysis, the factors influencing risk of cancer death in order of importance were. tumour size > 4 cm (P < 0.001), presence of nodes (P = 0.001), histology of adenoid cystic carcinoma (P = 0.01), high-tumour grade (P = 0.02) and perineural involvement (P = 0.01). Neither the extent of surgery nor the operator influenced outcome. Overall, adjuvant RT signi ficantly reduced locoregional recurrence (SG+RT 15% vs SG 43%; P = 0.002) b ut not survival, although on subanalysis, there was a trend to improved sur vival with large cancers and high-grade tumours. Long-term survival is dete rmined primarily by tumour characteristics, namely clinical stage and grade . Post-operative RT contributes significantly to locoregional control and p robably confers some survival advantage in high-risk patients.