Development of a patient and institutional-based model for estimation of operative times for robot-assisted radical cystectomy: results from the International Robotic Cystectomy Consortium

OBJECTIVES: To design a methodology to predict operative times for robot-assisted radical cystectomy (RARC) based on variation in institutional, patient, and disease characteristics to help in operating room scheduling and quality control. PATIENTS AND METHODS: The model included preoperative variables and therefore can be used for prediction of surgical times: institutional volume, age, gender, body mass index, American Society of Anesthesiologists score, history of prior surgery and radiation, clinical stage, neoadjuvant chemotherapy, type, technique of diversion, and the extent of lymph node dissection. A conditional inference tree method was used to fit a binary decision tree predicting operative time. Permutation tests were performed to determine the variables having the strongest association with surgical time. The data were split at the value of this variable resulting in the largest difference in means for the surgical time across the split. This process was repeated recursively on the resultant data sets until the permutation tests showed no significant association with operative time. RESULTS: In all, 2 134 procedures were included. The variable most strongly associated with surgical time was type of diversion, with ileal conduits being 70 min shorter (P 66 RARCs) was important, with those with a higher volume being 55 min shorter (P < 0.001). The regression tree output was in the form of box plots that show the median and ranges of surgical times according to the patient, disease, and institutional characteristics. CONCLUSION: We developed a method to estimate operative times for RARC based on patient, disease, and institutional metrics that can help operating room scheduling for RARC

Human kallikrein gene 13 (KLK13) expression by quantitative RT–PCR: an independent indicator of favourable prognosis in breast cancer

Kallikreins are a group of serine proteases with diverse physiological functions. KLK13 (previously known as KLK-L4) is a novel kallikrein gene located on chromosome 19q13.4 and shares a high degree of homology with other kallikrein family members. Many kallikrein genes were found to be differentially expressed in various malignancies, and their regulation is controlled by steroid hormones in prostate and breast cancer cell lines. We studied the expression of KLK13 by quantitative reverse transcriptase–polymerase chain reaction in 173 patients with epithelial breast carcinoma. An optimal cutoff point equal to the 40th percentile was defined, based on the ability of KLK13 to predict disease-free survival. KLK13 values were then associated with other established prognostic factors and with disease-free survival and overall survival. Higher positivity for KLK13 expression was found in older, oestrogen receptor positive patients. In univariate analysis, KLK13 expression is a significant predictor of improved disease-free survival and overall survival (P<0.001 and P=0.009, respectively). Cox multivariate analysis indicated that KLK13 was an independent prognostic variable in the subgroups of patients with Grade I–II tumours and in patients who were oestrogen receptor and progesterone receptor positive, and node positive. Hazard ratios derived from Cox analysis, related to disease-free survival and overall survival were 0.22 (P=0.001) and 0.24 (P=0.008), respectively, for the Grade I–II group; 0.36 (P=0.008) and 0.44 (P=0.038), respectively, for the node positive group and 0.36 (P=0.008) and 0.18 (P=0.008), respectively, for the oestrogen receptor positive group. The adjusted hazard ratio for progesterone receptor positive patients for disease-free survival was 0.25 (P=0.012). For patients in the node positive and oestrogen receptor positive subgroup (n=51) the adjusted hazard ratio was 0.25 (P=0.006) and for the node positive and progesterone receptor positive subgroup (n=46) the hazard ratio was 0.24 (P=0.008). Taken together, these data suggest that higher KLK13 expression in these subgroups of breast cancer patients is associated with an approximately 55 to 80% reduction in the risk of relapse or death. We conclude that KLK13 expression, as assessed by quantitative reverse transcriptase–polymerase chain reaction, is an independent favourable prognostic marker for breast carcinoma

Correlation of non-random chromosomal aberrations in lymphocytes of prostate cancer patients with specific clinical parameters

The purpose of this research was to correlate non-random chromosomal aberrations in the peripheral blood lymphocytes (PBLs) of prostate cancer patients with specific clinical parameters. Peripheral blood samples were analyzed from 59 informative prostate cancer patients. Non-random chromosomal alterations detected in the PBLs and their correlation with any specific clinical parameters were analyzed statistically. A comparison was made between specific chromosomal abnormalities in the patients having an early (<65 years) or late (greater than or equal to 65 years) age at disease onset, low-grade (Gleason grade <7) or high-grade (Gleason grade greater than or equal to 7) turners, a low (<10 ng/ml) or high (greater than or equal to 10 ng/ml) prostate-specific antigen (PSA) level, and androgen-sensitive or -insensitive disease. In examining the specific chromosomal breakpoints, the regions 1p13, 2q21, 3p21, 4q13, 5q31, 6p21, 7p15, 7p13, 7q32, 10p11, 10q26, 11p15, 11p11, 14q12, and 16q12 showed breaks in at least four cases. Chromosome 15 (P=0.045) was significantly altered in patients having a PSA value greater than or equal to 10, while it (P=0.017) and chromosome 19 (P=0.036) were significantly altered in patients having a PSA value greater than or equal to 20. In addition, chromosomes 5 (P=0.032), 8 (P=0.020), 16 (P=0.009), and 20 (P=0.047) were significantly altered in patients having a Gleason grade greater than 7. Also, chromosomes 2 (P=0.020) and 3 (P=0.044) were significantly altered in patients who had early disease onset. Additionally, chromosome 10 (P=0.041) was significantly altered in patients having metastasis, and chromosomes 4 (P=0.006) and 7 (P=0.028) were significantly altered in patients having androgen-insensitive disease. In spite of the small subset of patients, chromosome 8 (P=0.003) was significantly altered in patients having small cell carcinoma of the prostate. From these results we conclude that nonrandom chromosomal aberrations present in PBLs of prostate cancer patients can be correlated with specific clinical parameters. These correlations can be used to identify a prostate cancer patient's risk response to therapy