Comparison of 7 methods for sample size determination based on confidence interval estimation for a single proportion / 南方医科大学学报

OBJECTIVE@#To compare different methods for calculating sample size based on confidence interval estimation for a single proportion with different event incidences and precisions.@*METHODS@#We compared 7 methods, namely Wald, AgrestiCoull add z2, Agresti-Coull add 4, Wilson Score, Clopper-Pearson, Mid-p, and Jefferys, for confidence interval estimation for a single proportion. The sample size was calculated using the search method with different parameter settings (proportion of specified events and half width of the confidence interval [ω=0.05, 0.1]). With Monte Carlo simulation, the estimated sample size was used to simulate and compare the width of the confidence interval, the coverage of the confidence interval and the ratio of the noncoverage probability.@*RESULTS@#For a high accuracy requirement (ω =0.05), the Mid-p method and Clopper Pearson method performed better when the incidence of events was low (P < 0.15). In other settings, the performance of the 7 methods did not differ significantly except for a poor symmetry of the Wald method. In the setting of ω=0.1 with a very low p (0.01-0.05), failure of iteration occurred with nearly all the methods except for the Clopper-Pearson method.@*CONCLUSION@#Different sample size determination methods based on confidence interval estimation should be selected for single proportions with different parameter settings.

Expanded curettage and bone cement filling combined with internal fixation for the treatment of Campanacci III giant cell tumour of knee joint / 中国骨伤

OBJECTIVE@#To evaluate clinical effects of expanded curettage and bone cement filling combined with internal fixation in treating Campanacci III giant cell tumor of knee joint.@*METHODS@#From January 2006 to December 2016, 21 patients with Campanacci III giant cell tumor of knee joint were treated by expanded curettage and bone cement filling combined with internal fixation, including 11 males and 10 females with an average age of(35.24±10.56) years old (ranged from 21 to 61 years old). The courses of disease ranged from 1.5 to 24.0 months with an average of(8.1±4.4) months. Among them, 8 patients were distal femur and 13 patients were proximal tibia. All patients were primary tumors. Musculoskeletal Tumor Society(MSTS) scores were used to evaluate lower limb function before and after operation. X-ray was used to observe healing of lesions and the occurrence of adverse reactions.@*RESULTS@#All incisions were healed at grade A without complications such as infection and internal fixation failure. All patients were followed up from 8 to 56 months with an average of (29.62±9.48) months. MSTS score at the latest follow-up 26.71±2.35 was higher than that of before operation 15.24±1.14, and had statistical significance(=20.160, =0.000). The results of X-ray at final following-up showed internal fixation was well, and no loosening and fracture of subchondral bone. Three patients recurred giant cell tumor and replaced with tumor prosthesis.@*CONCLUSIONS@#Expanded curettage and bone cement filling with internal fixation for the treatment of Campanacci III giant cell tumor of knee joint could effectively retain limb function and reduce tumor recurrence rate.

The clinical features of breast cancer in young patients / 肿瘤

Objective: To explore and compare the clinical and pathologic features of breast cancer between the young women ( 0.05). The proportion of Luminal B was higher in the young patients than that in the elder patients. The median survial time was not significantly different between the young and the elder patients (58.2 vs 45.8 months, P > 0.05). The univariate analysis revealed that PR-negative and lymph node and distant metastases were associated with lower five-year survival rate in young patients (P < 0.05). The multivariate analysis revealed that lymph node and distant metastases were independent prognostic factors in young patients (P < 0.05). Conclusion: Young patients with breast cancer have more poor prognostic factors than the elders, such as later stages of tumor size and lymph node, more proportion of type Luminal B, and higher rate of breast-conserving radical surgery, but the overall survival between the young and the elder patients had no significant difference.