Compromised local control due to treatment interruptions and late treatment breaks in early glottic cancer: Population-based outcomes study supporting need for intensified treatment schedules.

Purpose: This population-based study describes the treatment of early glottic cancer in Ontario, Canada and assesses whether treatment variations were associated with treatment effectiveness.

Methods And Materials: We studied 491 T1N0 and 213 T2N0 patients. Data abstracted from charts included age, sex, stage, treatment details, disease control, and survival.

Management and outcome differences in supraglottic cancer between Ontario, Canada, and the Surveillance, Epidemiology, and End Results areas of the United States.

Purpose: We compared the management and outcome of supraglottic cancer in Ontario, Canada, with that in the Surveillance, Epidemiology, and End Results (SEER) Program areas in the United States.

Methods: Electronic, clinical, and hospital data were linked to cancer registry data and supplemented by chart review where necessary. Stage-stratified analyses compared initial treatment and survival in the SEER areas (n = 1,643) with a random sample from Ontario (n = 265).

Cancer incidence and mortality in northeastern Ontario, 1991-1998.

Background: This descriptive epidemiology study reports the cancer incidence and mortality experience of Northeastern Ontario residents during the 8-year period from 1991-1998.

Methods: Standardized Incidence Ratios (SIRs), Standardized Mortality Ratios (SMRs) and 95% confidence intervals (CI) were calculated for a number of cancer sites (n = 25 for males, n = 26 for females), using rates determined from the Ontario population as the referent population.

Results: During the period 1991-1998, 24,019 cases of primary incident cancers (excluding non-melanotic skin cancer) and 11,677 deaths attributed to cancer occurred in Northeastern Ontario residents.

A comparison of published head and neck stage groupings in laryngeal cancer using data from two countries.

The combination of T, N, and M classifications into stage groupings is meant to facilitate a number of activities including: the estimation of prognosis and the comparison of therapeutic interventions among similar groups of cases. We tested the UICC/AJCC fifth edition stage grouping and six other TNM-based groupings proposed for head and neck cancer for their ability to meet these expectations in laryngeal cancer using data from Ontario, Canada, and the area of Southern Norway surrounding Oslo. We defined four criteria to assess each grouping scheme: (1) the subgroups defined by T, N, and M comprising a given group within a grouping scheme have similar survival rates (hazard consistency); (2) the survival rates differ among the groups (hazard discrimination); (3) the prediction of cure is high (outcome prediction); and (4) the distribution of patients among the groups is balanced.