Oral mucosal side effects of cytotoxic chemotherapy of testicular cancer. A retrospective study

Chemotherapy-associated oral microbiome changes in breast cancer patients

Cytotoxic chemotherapy with or without a combination of humanized monoclonal antibodies is regarded as the gold standard of personalized medicine for the treatment of breast cancer patients. Significant medication-related side effects are common accompanying phenomena for these patients, such as oral discomfort, mucositis, or even osteonecrosis of the jaw. In this study, we analyze the saliva samples of 20 breast cancer patients at three time points throughout their chemotherapy: at the baseline prior to treatment initiation (T1), after four-to-six cycles of chemotherapy (T2), and 1 year after the start of the treatment (T3) to investigate and characterize the long-term effects of chemotherapy on the oral microbiome. We aimed to characterize changes in the oral bacterial microbiome based on 16S rRNA gene amplicon analysis during chemotherapeutic treatment, as a potential target to treat common oral side effects occurring during therapy. The chemotherapeutic drugs used in our study for patient treatment were trastuzumab, docetaxel, pertuzumab, epirubicin, and cyclophosphamide. We find a significant increase in the relative abundance of potentially pathogenic taxa like Escherichia/Shigella and non-significant trends in the relative abundance of, for example, Actinomyces ssp. In conclusion, the role of microbiota in the oral side effects of chemotherapeutic treatment needs to be considered and should be analyzed in more detail using larger patient cohorts. Oral side effects in breast cancer patients undergoing chemotherapy are a common burden and should be treated for a better tolerability of the therapy.

Impact of Saliva and Cariogenic Microbiota on the Chemotherapy-Induced Oral Mucositis in Oncopediatric Patients: A Preliminary Longitudinal Study

This study aims to evaluate the salivary parameters and cariogenic microbiota of pediatric oncological patients and their correlation with severe oral mucositis (SOM). A preliminary longitudinal study included patients in the age range from 4 to 18 years (n = 26), with diagnosis of primary cancer, who were followed up before and after time intervals of two, five, and ten weeks of induction chemotherapy. Oral mucosa examinations were performed by means of the modified Oral Assessment Guide (OAG) by calibrated examiners (κ > 0.70). Saliva analysis (unstimulated saliva flow (USF), clinical saliva viscosity (CSV), and pH) and microbiological (total Streptococcus (TS) and Streptococcus of the mutans group (SMG)) tests were performed using unstimulated saliva. The data were analyzed by the Wilcoxon and Spearman Correlation tests (α = 5%). The patients were predominantly of the female sex (n = 15; 57.7%), adolescents (n = 15; 57.7%), and patients with hematological tumors (n = 21; 80.8%). SOM was more frequent in the tenth week (n = 7; 28.6%). The values of USF, CSV, pH, TS, and SMG were not changed by the institution of chemotherapy (p > 0.05). These values were correlated with SOM and the time, TS and SMG, and CSV and SMG. The salivary and microbiological parameters investigated did not influence the severity of oral mucositis in the pediatric patients oncological..

The influence of Cisplatin-based chemotherapy on the osseointegration of dental implants: An in vivo mechanical and histometrical study

OBJECTIVES

To evaluate the effect of Cisplatin on bone repair and mineralization around implants and on the mechanical properties of bone tissue.

MATERIALS AND METHODS

Forty-three Wistar rats were randomly divided into two groups: Cisplatin (CIS, medication) and control (CTL, placebo solution), administered once a week for 4 weeks. After 4 weeks, implants were installed in both tibiae metaphysis. After 30 and 60 days, the animals were sacrificed and their femurs and tibiae were removed. Femurs were subjected to mechanical tests and tibiae for removal torque, arrangement and distribution of collagen fibers, morphometrical analyses (bone tissue in contact with the implant surface [BIC] and areal fraction between implant threads occupied by bone tissue [BAFO]) and scanning electron microscopy to calcium and calcium/phosphorus analysis. Data were analyzed by ANOVA or MANOVA, and Tukey or Games-Howell post hoc tests, respectively (α = 0.05).

RESULTS

The CTL specimens had significantly higher values (0.0001 ≤ p≤0.036) of strength (N), removal torque (N/cm² ), %BIC, and %BAFO than CIS specimens, being their best results at day 60. No significant differences were found among the groups regarding the values of deformation, percentage of calcium, and calcium/phosphorus ratio. In CIS groups, there was a reduction in the organization of collagen at the bone/implant interface, resulting in a trabecular bone with thin trabeculae and birefringent collagen and irregular arrangement.

CONCLUSIONS AND CLINICAL IMPLICATIONS

Cisplatin interfered negatively in the repair and mineralization around dental implants, as well as on the quality of the bone tissue, mainly in the period of 30 days after the implant placement.

Effects of cisplatin chemotherapy on the osseointegration of titanium implants

PURPOSE

The effect of chemotherapy on the osseointegration of dental implants has received less interest compared with radiotherapy. Thus, the aim of the current study was to investigate the effect of cisplatin chemotherapy on the osseointegration of dental implants in a rabbit model.

MATERIALS AND METHODS

Sixteen New Zealand White rabbits were randomly assigned to two groups of treatment of either cisplatin at 2.5 mg/kg/week for 4 weeks (n = 8) or placebo (n = 8), in which the first dose was administered 2 days prior to the surgical procedure. Each rabbit received one titanium dental implant inserted in the right distal femoral condyle. Four rabbits from each group were sacrificed 4 and 8 weeks after implant insertion. Osseointegration of the dental implants was analysed using micro-computed tomography and histomorphometric evaluation.

RESULTS

Analysis of micro-computed tomography data and histomorphometric data showed that the osseointegration parameters, including the ratio of bone volume to total volume (BV/TV) and bone-implant contact (BIC%) for the cisplatin group, were significantly lower compared to the control group at 4 and 8 weeks. (P ≤ 0.05).

CONCLUSION

Cisplatin chemotherapy had a negative effect on the osseointegration of dental implants when inserted throughout the chemotherapeutic regimens in a rabbit model.

Chemotherapeutic and antiresorptive combination therapy suppressed lymphangiogenesis and induced osteonecrosis of the jaw-like lesions in mice

Osteonecrosis of the jaw (ONJ) is a serious adverse event that occurs predominantly in patients on both antiresorptive and antineoplastic therapies. However, how these combination therapies are connected to the high frequency of ONJ in this particular patient population is unclear. This study's aim was to determine a mechanism of ONJ associated with the combination therapy of antiresorptives and chemotherapeutics. Mice received zoledronic acid (ZA) in conjunction with melphalan or dexamethasone. The maxillary first molars were extracted 3 weeks after the initiation of treatment and wound healing assessed at 4 weeks post-extractions using microcomputed tomography and immunohistochemistry. Mice receiving the combination treatment of ZA and melphalan developed ONJ-like lesions, while ONJ-like lesions were not found in mice on ZA or melphalan monotherapy, or the combination treatment of ZA and dexamethasone. ONJ lesions were characterized by a lack of epithelium, exposed necrotic bone, severe inflammatory cell infiltration, and minimal bone formation. Fluorescent immunohistochemistry showed that lymphatic vessel formation was significantly suppressed in ONJ-like lesions with a concomitant decrease in F4/80(+) macrophages expressing vascular endothelial growth factor C (VEGFC). Interestingly, significantly suppressed lymphatics were also found in the draining lymph nodes of mice on the combination treatment of ZA and melphalan. Thus, suppressed lymphangiogenesis was strongly associated with the development of ONJ-like lesions in the current study. Since lymphangiogenesis is critical in the resolution of inflammation during wound healing, inflammation control may serve as a potential strategy to prevent ONJ.

Determinants of severe oral mucositis in paediatric cancer patients: a prospective study

OBJECTIVE

To analyse the incidence and the determinants of severe oral mucositis (OM) in young cancer patients treated by standard chemotherapy.

METHODS

The study was carried out at the Pediatric Hemato-Oncology unit of Children's Hospital of Rabat. Patients under 16 years of age with malignant disease treated by chemotherapy between January 2001 and December 2006 were recorded.

RESULTS

Consecutive patients (n = 970) with malignant disease were studied. The age ranges from 2 months to 16 years (mean, 6.8 ± 4.1 years). OM occurred in 540 (55.6%) patients, and 17.9% of them encountered severe grades. Mean time to onset of the lesions was 10.5 ± 6.8 (range, 1-22 days) and mean duration was 6.8 ± 3.1 (range, 2-23 days). All chemotherapeutic protocols were associated with OM development (range, 20-100%). Patients with severe OM were more likely to have undifferentiated carcinoma of nasopharyngeal type (RR = 2.6, 95% IC 1.1-6.1), non-Hodgkin lymphoma (RR = 2.1, 95% CI 1.2-2.4) and acute leukaemia (RR = 1.7, 95% CI 1.5-3.6). Methotrexate-based therapies were also associated with the worsening of OM (RR = 1.7, 95% IC 1.2-2.6).

CONCLUSION

Underlying disease and chemotherapy regimens are the principal risk factors of OM development. This model can help in the identification of patients at risk for adequate preventive and therapeutic measures.

Oral complications during treatment of malignant diseases in childhood: effects of tooth brushing

During anticancer treatment, oral lesions considerably aggravate the child's clinical condition and increase the risk of infection. This prospective study evaluated the incidence, nature and chronology of oral complications arising during the first 6 weeks of chemotherapy. 131 children were included in this study, and their oral and dental health evaluated on enrolment. Each child was observed once a week, for 6 weeks. Fifty-two per cent (68/131) of the children presented with at least one oral lesion. Two oral healthcare regimens (with or without tooth brushing) were evaluated. Tooth brushing significantly reduced the number of children affected. Standardised multicentre studies should permit the definition of oral care regimens which would eliminate pain and reduce the risk of infection in children hospitalised for cancer.