Objective　Exploring how to check the proportional hazards assumption of the Cox model,and the solutions to non-proportional hazards between the covariates and the hazard function.Methods　With a example data set of Ⅲc stage ovarian serous cystadenocarcina,illustrating how to use graphical methods to check the proportional hazards assumption of the Cox model.Results　the predictor of post-surgery administering medicine times violated the proportional hazards assumption of the Cox model.Conclusion　when using the Cox model to analyze the predictors of survival time,checking whether the predictors violate the proportional hazards assumption of the Cox model or not should be paid attention to.

Objective To explore the influencing factors for postoperative adjuvant chemotherapy effects in elderly patients with breast cancer. Methods Five hundred and ninety female patients aged 65 years or older with invasive breast cancer were treated in our hospital, and the influencing factors for postoperative adjuvant chemotherapy effects were analyzed by chi-square test and logistic regression. Results Two hundred and thirty-one (39.2%) patients received postoperative adjuvant chemotherapy. The results showed that diabetes, age, patterns of operation and pathological characteristics of tumor had significant influences on postoperative adjuvant chemotherapy effects (χ2=4.49,88. 27,23.49 and 9.40, all P<0.05). Logistic regression analysis showed that age, tumor size, lymph node status(pN) and estrogen receptor (ER) status were related to postoperative adjuvant chemotherapy effects(χ2=68.857,15. 284,43. 540 and 7.009 ,all P<0.01). Forty-four patients (66.7%) with pN(+)/ER(-) received adjuvant chemotherapy. Conclusions Age, tumor size, lymph node status and ER status were independent predictive factors for postoperative adjuvant chemotherapy effects in elderly patients with breast cancer.