Background: In order to find whether the changes in primary tumor definition influence the distribution of T (tumor extent) stages and prognoses, a retrospective study was undertaken.
Patients and methods: There were 1,040 patients with adequate data for staging and 868 of those patients underwent surgical treatment. Among the surgically treated patients, 187 fulfilled the new (American Joint Committee on Cancer [AJCC]/International Union Against Cancer 1988) and 77 fulfilled the old (AJCC 1977) criteria for T4 tumors. The distribution of all patients, rate of patients initially treated with surgery, incidence of metastases, and survival were analyzed.
Results: The neck was clinically positive (N+) in 50% of T4 patients staged according to the new rules and 69% of patients staged according to the old rules. The 5-year overall survival rate for T4-staged patients irrespective of therapy was 29% using the new rules and 13% using the old rules. The 5-year disease-free survival rate for T4-operated patients was 60% using the new rules and 45% using the old rules.
Conclusions: The previous AJCC rules for the T4 tumors were a better indicator of poor prognosis.