Studies on risk factors of infection and impact on oncological outcome in prosthesis-based breast reconstruction among breast cancer patients

• Main Authors: Cheng-Feng Chen, 陳呈峰
• Other Authors: Pesus Chou
• Format: Others
• Language: en_US
• Published: 2016
• Online Access: http://ndltd.ncl.edu.tw/handle/4h4cz9

博士 === 國立陽明大學 === 公共衛生研究所 === 105 === Part 1: Risk of infection is associated more with drain duration than daily drainage volume in prosthesis-based breast reconstruction: a cohort study Background: In prosthesis-based breast reconstruction, drains are used to prevent seroma formation and to reduce the risk of infection. However, prolonged drainage increases the risk of ascending infection. Although the volume often accepted for drain removal is <30 ml per day, the optimal timing to remove the drain for best clinical outcome remains controversial. Methods: We did a retrospective cohort study of 569 patients of prosthesis-based breast reconstruction with infection rate as the outcome variable; drain duration and last daily drainage volume as the main independent variables. Data on age, smoking history, diabetes mellitus history, body mass index, breast weight, tissue expander size, drain size, number of retrieved lymph nodes, tumor size, number of metastatic lymph nodes, tumor stage, mastectomy type, reconstruction type, submuscular implantation, skin defect, operative time, duration of antibiotics use, chemotherapy ,and radiotherapy were collected as covariates. Multivariable logistic regression analysis was used to control for confounding. Results: The total infection rate was 5.1% (29/569). The daily drainage volume ≥30ml/day at the time of drain removal was not found associated with increased infection rate (p=.32). Of the various cutoff values of last daily drainage volume, none was found to be a determinant for drain removal where the risk of infection was concerned. By contrast, drain duration over 21 days significantly increased infection rate (p=.001). The multivariable logistic regression analysis showed an increase of 76.2% in the infection rate with each additional week of drain retention (p=.001). Breast weight also had a significant influence on risk of infection. Chemotherapy and drain size showed borderline effect on risk of infection whereas the last daily drainage volume was not associated with risk of infection Conclusions: In summary, our study revealed that drain duration, rather than the last daily drainage volume, significantly affects the infection rate in prosthesis-based breast reconstruction. We recommend that the drain is better removed no longer than 3 weeks postoperatively and can be removed as early as postoperative day 7, even when the drainage is over 30 ml in a 24 hour period. Part II: Does prosthesis-based breast reconstruction affect postmastectomy radiotherapy? A clinical outcome-based study. Abstract: Background: In the last five decades, there has been significant advancement of breast reconstruction and postmastectomy radiotherapy for breast cancer care. There has been concern that breast reconstruction may affect the efficacy of postmastectomy radiotherapy. This however, has not been proven by clear clinical evidence. Methods: By comparing the locoregional recurrence rates between those with and without prosthesis-based breast reconstruction after postmastectomy radiotherapy, a retrospective cohort study of the breast cancer patients was done. Multivariate survival analysis was used to control the confounding factors. Results: Between 1998 and 2011, 1015 patients receiving postmastectomy radiotherapy were identified. Among them, 111 patients (study group) had prosthesis-based breast reconstruction and the other 904 did not have breast reconstruction (control group). Thirty four out of 904 (3.8%) patients in the control group and four out of 111 (3.6%) patients in the study group developed locoregional recurrence. Multivariate survival analysis found no significant difference both in locoregional recurrence free survival (Hazard ratio = 0.852, P-value = 0.771) and in overall survival (Hazard ratio = 1.317, P-value = 0.246) between control group and study group. Conclusions: There is no statistically significant difference in the locoregional recurrence free survival or overall survival between breast cancer patients receiving postmastectomy radiotherapy with and without prosthesis-based breast reconstruction. Although postmastectomy radiotherapy adversely impacts the surgical and cosmetic outcome of breast reconstruction, the oncologic outcome of postmastectomy radiotherapy is not significantly influenced by prosthesis-based breast reconstruction.