Cox9s Proportional Hazard Model Research Articles

Prognostic Value of Age and Distant Metastasis in Differentiated Thyroid Carcinoma Undergoing Salvage Surgery.

To investigate the association between survival outcomes and clinicopathological factors, including pathological restaging based on the UICC8th, among patients with recurrence differentiated thyroid carcinoma undergoing salvage surgery of local site. A total of 54 patients who underwent salvage surgery of local site for recurrence differentiated thyroid carcinoma were enrolled. The optimal cutoff ages at salvage surgery for predicting death and cancer-specific death were determined by receiver operating curve analysis. Overall and cancer-specific survivals were determined using log-rank test and Cox's proportional hazards model. Univariate analysis showed that age and the presence of distant metastasis at salvage surgery were significantly associated with overall survival (p=0.01 and p<0.05, respectively) and cancer-specific survival (p=0.02 and p=0.01, respectively). The optimal cutoff age at salvage surgery for predicting the detection of both death (p=0.01) and cancer-specific death (p=0.02) was 65 years. Multivariate analysis showed that age ≥65 years and the presence of distant metastasis were significantly associated with shorter overall survival (p<0.01 and p=0.03, respectively) and shorter cancer-specific survival (p<0.01 and p=0.01, respectively). Older age and the presence of distant metastasis at salvage surgery of local site were identified as predictors for poor survival outcomes in recurrence differentiated thyroid carcinoma.

Survival outcome of care by specialist surgeons in breast cancer: a study of 3786 patients in the west of Scotland

To compare survival outcome for patients with breast cancer cared for by specialist and non-specialist surgeons in a geographically defined area. Retrospective study of all female patients aged under 75 years in the area treated between 1980 and June 1988 (before breast screening began). Patients were identified from the cancer registry and from pathology records of all hospitals in the area. Specialist surgeons were identified by one author. All other surgeons caring for patients from the area were considered non-specialists. A geographically defined population in urban west of Scotland. 3786 patients with histologically verified breast cancer operated on between 1 January 1980 and 30 June 1988 and followed to 31 December 1993. Five and 10 year survival rates for specialists and non-specialists; relative hazard ratios derived from Cox's proportional hazards model adjusted for prognostic factors--age, socioeconomic status, tumour size, and nodal involvement. The five year survival rate was 9% higher and the 10 year survival 8% higher for patients cared for by specialist surgeons. A reduction in risk of dying of 16% (95% confidence interval 6% to 25%) was found after adjustment for age, tumour size, socioeconomic status, and nodal involvement. The benefit of specialist care was apparent for all age groups, for small and large tumours, and for tumours that did and did not affect the nodes and was consistent across all socioeconomic categories. Survival differences of the magnitude demonstrated have implications for the provision of services for the treatment of women with breast cancer. There is a need to improve equity in the treatment of breast cancer.