Prognostic factors in T2 glottic cancer

During a ten-year period from 1965 through 1974, 164 patients with T2N0M0 glottic cancer were seen at the Princess Margaret Hospital. These patients were treated by radiotherapy reserving surgery for salvage of recurrent or persistent disease. One hundred and fifty-four cases have been analyzed in detail with respect to two variables: impairment of mobility and surface extension of disease. Two end-points of analysis were used: actuarial local recurrence-free rates and corrected actuarial survival. The five-year corrected actuarial survival rate was 12% less in the T2N0M0 patients with impaired vocal cord mobility (75.2%) when compared to those cases with normal vocal cord mobility (86.8%) (P = 0.068). No difference in survival was seen with increasing degrees of surface extension of disease when correction for the effects of impairment of mobility was performed. There was a highly significant difference in local control rates with radiotherapy when comparing cases with normal vocal cord mobility (76.7% locally controlled) vs. impaired vocal cord mobility (51.1% locally controlled) (P = 0.015). Again, no significant trend in local control rates could be ascertained with increasing surface extension of disease. The number of patients with nodal disease was insufficient to permit meaningful analysis of the effects of the presence or absence of nodal disease on survival. On the basis of this analysis, we suggest that the Stage T2 grouping in glottic cancer be subdivided into Stage T2a for those tumors with normal vocal cord mobility and T2b for those with impaired vocal cord mobility.