Radiation-induced microenvironments--the molecular basis for free flap complications in the pre-irradiated field?

Matrix Metalloproteinases and Their Inhibitors as Potential Prognostic Biomarkers in Head and Neck Cancer after Radiotherapy

Head and neck cancer (HNC) is among the ten most frequent tumours, with 5-year survival rates varying from 30% to 70% depending on the stage and location of the tumour. HNC is traditionally known as head and neck squamous cell carcinoma (HNSCC), since 90% arises from epithelial cells. Metastasis remains a major cause of mortality in patients with HNSCC. HNSCC patients with metastatic disease have an extremely poor prognosis with a survival rate of less than a year. Matrix metalloproteinases (MMPs) have been described as biomarkers that promote cell migration and invasion. Radiotherapy is widely used to treat HNSCC, being a determining factor in the alteration of the tumour's biology and microenvironment. This review focuses on analysing the current state of the scientific literature on this topic. Although few studies have focused on the role of these proteinases in HNC, some authors have concluded that radiotherapy alters the behaviour of MMPs and tissue inhibitors of metalloproteinases (TIMPs). Therefore, more research is needed to understand the roles played by MMPs and their inhibitors (TIMPs) as prognostic biomarkers in patients with HNC and their involvement in the response to radiotherapy.

Surgical prevention of pharyngocutaneous fistula in salvage total laryngectomy: a systematic review and network meta-analysis

PURPOSE

To compare the efficacy of different reconstructive techniques in preventing pharyngocutaneous fistula (PCF) after salvage total laryngectomy (STL).

METHODS

An arm-based network analysis was conducted using a Bayesian hierarchical model according to the PRISMA-NMA guidelines.

RESULTS

A total of 1694 patients with a median age of 64 years (n = 1569, 95% CI: 62-66 years) were included. If compared to primary pharyngeal closure alone, only a pedicled flap onlay (PFO) showed a statistically significant reduction in PCF rate (OR: 0.35, CI: 0.20-0.61). PFO seemed to perform better than other treatments according to the rank probabilities test (39.9% chance of ranking first).

CONCLUSIONS

A pedicled flap placed with an overlay technique might be preferred over a patch reconstruction to prevent PCF after STL.

Osteocutaneous-flap-related osteomyelitis following mandibular reconstruction: a cohort study of an emerging and complex bone infection

Abstract. Osteocutaneous flap (OCF) mandible reconstruction is at high risk for surgical site infection. This study aimed to describe diagnosis, management, and outcome of OCF-related osteomyelitis. All patients managed at our institution for an OCF-related osteomyelitis following mandible reconstruction were included in a retrospective cohort study (2012–2019). Microbiology was described according to gold-standard surgical samples, considering all virulent pathogens, and potential contaminants if present on at least two samples. Determinants of treatment failure were assessed by logistic regression and Kaplan–Meier curve analysis. The 48 included patients (median age 60.5 (IQR, 52.4–66.6) years) benefited from OCF mandible reconstruction mostly for carcinoma (n=27/48; 56.3 %) or osteoradionecrosis (n=12/48; 25.0 %). OCF-related osteomyelitis was mostly early (≤3 months post-surgery; n=43/48; 89.6 %), presenting with local inflammation (n=28/47; 59.6 %), nonunion (wound dehiscence) or sinus tract (n=28/47; 59.6 %), and/or bone or device exposure (n=21/47; 44.7 %). Main implicated pathogens were Enterobacteriaceae (n=25/41; 61.0 %), streptococci (n=22/41; 53.7 %), Staphylococcus aureus (n=10/41; 24.4 %), enterococci (n=9/41; 22.0 %), non-fermenting Gram-negative bacilli (n=8/41; 19.5 %), and anaerobes (n=8/41; 19.5 %). Thirty-nine patients (81.3 %) benefited from surgery, consisting of debridement with implant retention (DAIR) in 25/39 (64.1 %) cases, associated with 93 (IQR, 64–128) days of antimicrobial therapy. After a follow-up of 18 (IQR, 11–31) months, 24/48 (50.0 %) treatment failures were observed. Determinants of treatment outcomes were DAIR (OR, 3.333; 95 % CI, 1.020–10.898) and an early infectious disease specialist referral (OR, 0.236 if ≤2 weeks; 95 % CI, 0.062–0.933). OCF-related osteomyelitis following mandibular reconstruction represents difficult-to-treat infections. Our results advocate for a multidisciplinary management, including an early infectious-disease-specialist referral to manage the antimicrobial therapy driven by complex microbiological documentation.

Influence of preoperative radiotherapy on head and neck free-flap reconstruction: Systematic review and meta-analysis

The effect of preoperative external radiotherapy (XRT) on head and neck free-flap reconstruction is still controversial. In this study, we aimed to determine the impact of preoperative XRT on the outcomes of head and neck microvascular free-flap reconstruction. A systematic review and meta-analysis was conducted in concordance with the Systematic reviews and Meta-Analyses protocol. We searched several databases (PubMed, EMBASE, Web of Science, and Cochrane Library) to find published papers on the topic. The R program was used for data synthesis and statistical heterogeneity evaluation; then, fixed effect or random effect models were used. A total of 37 studies, involving 12 408 patients with 12 668 flaps, were included in this meta-analysis. The overall flap success rate for all studies was 94.4%. Pooled analysis showed that patients with preoperative XRT were significantly associated with an increased risk of total flap failure (odds ratio [OR] = 1.80, 95% confidence interval [CI] = 1.45-2.23, P < .001), partial flap failure (OR = 1.90, 95% CI = 1.07-3.38, P = .029), and postoperative complication rates (OR = 2.22, 95% CI = 1.64-2.72, P < .001). Our study suggests that preoperative XRT is associated with an increased risk of developing free-flap failure and an increased postoperative complication rate.

Efficacy of Aeschynomene indica L. leaves for wound healing and isolation of active constituent

ETHNOPHARMACOLOGICAL RELEVANCE

In traditional Chinese medicine, the aerial parts of Aeschynomene indica L. (AIL) have been used for wound healing, and to treat urinary tract infection, hepatitis, enteritis, dysentery, nyctalopia, conjunctivitis, urticaria, and furuncle. However, no scientific investigation has been conducted on its wound healing potential.

AIM OF THE STUDY

To investigate the effects of AIL extract on wound healing, isolate the active constituent and reveal the possible mechanism of enhancing wound healing.

MATERIALS AND METHODS

The circular excision wound healing model was used to evaluate in vivo wound-healing activity. Hematoxylin and eosin staining was applied to assess inflammatory cells infiltration, angiogenesis, fibroblast proliferation, collagen synthesis, collagen remodeling, and skin appendages generation. Sirius red-picric acid staining was employed for quantitative analysis of the ratio of collagen I/III. Immunohistochemical staining for CD68, CCR7 (CD197), CD163, TGF-β1 and α-SMA was performed to determine macrophages phenotypes transition (M1-to-M2) and prove the scar-improving effect of AIL on wound healing.

RESULTS

We successfully isolated the active constituent (Sub-Fr0.2) for wound healing from AIL extract, circular excision wound healing experiment and hematoxylin & eosin staining showed Sub-Fr0.2 has a significant promoting effect on wound healing. Results of sirius red-picric acid staining demonstrated a reduced ratio of collagen I/III in the Sub-Fr0.2 group as compared with the vehicle group. Immunohistochemical staining for CD68, CCR7 (CD197), and CD163 in the Sub-Fr0.2 group exhibited an elevated speed of macrophages transiting from M1 phenotype to M2 phenotype, when compared with the vehicle group. Besides, the expression of TGF-β1 and α-SMA were inhibited on wounds treated with the ointment containing Sub-Fr0.2.

CONCLUSION

Leaves of AIL and its active constituent (Sub-Fr0.2) effectively promoted wound healing and reduced scar formation, this efficacy might be exerted by accelerating macrophages phenotypes transition and inhibiting TGF-β1 and α-SMA expression.

Bone marrow cell extract promotes the regeneration of irradiated bone

Mandibular osteoradionecrosis is a severe side effect of radiotherapy after the treatment of squamous cell carcinomas of the upper aerodigestive tract. As an alternative to its treatment by micro-anastomosed free-flaps, preclinical tissular engineering studies have been developed. Total bone marrow (TBM) associated with biphasic calcium phosphate (BCP) significantly enhanced bone formation in irradiated bone. One mechanism, explaining how bone marrow cells can help regenerate tissues like this, is the paracrine effect. The bone marrow cell extract (BMCE) makes use of this paracrine mechanism by keeping only the soluble factors such as growth factors and cytokines. It has provided significant results in repairing various tissues, but has not yet been studied in irradiated bone reconstruction. The purpose of this study was to evaluate the effect of BMCE via an intraosseous or intravenous delivery, with a calcium phosphate scaffold, in irradiated bone reconstruction.

Twenty rats were irradiated on their hind limbs with a single 80-Gy dose. Three weeks later, surgery was performed to create osseous defects. The intraosseous group (n = 12) studied the effect of BMCE in situ, with six combinations (empty defect, BCP, TBM, BCP-TBM, lysate only, BCP-lysate). After four different combinations of implantation (empty defect, BCP, TBM, BCP-TBM), the intravenous group (n = 8) received four intravenous injections of BMCE for 2 weeks. Five weeks after implantation, samples were explanted for histological and scanning electron microscopy analysis. Lysate immunogenicity was studied with various mixed lymphocyte reactions.

Intravenous injections of BMCE led to a significant new bone formation compared to the intraosseous group. The BCP-TBM mixture remained the most effective in the intraosseous group. However, intravenous injections were more effective, with TBM placed in the defect, with or without biomaterials. Histologically, highly cellularized bone marrow was observed in the defects after intravenous injections, and not after an in situ use of the lysate. The mixed lymphocyte reactions did not show any proliferation after 3, 5, or 7 days of lysate incubation with lymphocytes from another species.

This study evaluated the role of BMCE in irradiated bone reconstruction. There were significant results arguing in favor of BMCE intravenous injections. This could open new perspectives to irradiated bone reconstruction.

Free flap outcome of salvage surgery compared to primary surgery for head and neck defects: A propensity score analysis

OBJECTIVES

To compare free flap outcomes for head and neck defects between primary surgery and salvage surgery and identify factors affecting the outcomes in the two settings.

METHODS

A total of 225 patients (primary group, n=56; salvage group, n=169) were retrospectively identified. The salvage group was previously treated with radiotherapy, chemoradiation, surgery, or any combination of these treatments. Clinical data were retrieved and analyzed between the two groups to compare the incidence and contributing factors of flap-related complications and flap failure. A propensity score analysis with matching T stage, defect, and flap types was also performed for unbiased comparisons.

RESULTS

Flap-related complication rate was 22.2% in all patients. The salvage group showed higher rates of wound dehiscence than the primary group (3.6% in primary vs. 13.0% in salvage; p=0.04). Flap failures occurred in 10 patients (4.4%), including 3 (5.4%) in the primary group and 7 (4.1%) in the salvage group (p=0.71). Multivariate analysis showed no critical factor that influenced the occurrence of flap-related complications or flap failure, including surgery type (primary or salvage). In propensity score analysis, incidences and types of flap-related complications and flap failure were not statistically different between the two groups (primary and salvage).

CONCLUSIONS

Free flap reconstruction is a safe and reliable method to restore the ablative defects in previously irradiated or operated head and neck defects.

Living Donor Liver Transplantation for Advanced Hepatocellular Carcinoma with Portal Vein Tumor Thrombosis after Concurrent Chemoradiation Therapy

Locally advanced hepatocellular carcinoma (HCC) with portal vein thrombosis carries a 1-year survival rate <10%. Localized concurrent chemoradiotherapy (CCRT), followed by hepatic arterial infusion chemotherapy (HAIC), was recently introduced in this setting. Here, we report our early experience with living donor liver transplantation (LDLT) in such patients after successful down-staging of HCC through CCRT and HAIC. Between December 2011 and September 2012, eight patients with locally advanced HCC at initial diagnosis were given CCRT, followed by HAIC, and underwent LDLT at the Severance Hospital, Seoul, Korea. CCRT [45 Gy over 5 weeks with 5-fluorouracil (5-FU) as HAIC] was followed by HAIC (5-FU/cisplatin combination every 4 weeks for 3-12 months), adjusted for tumor response. Down-staging succeeded in all eight patients, leaving no viable tumor thrombi in major vessels, although three patients first underwent hepatic resections. Due to deteriorating liver function, transplantation was the sole therapeutic option and offered a chance for cure. The 1-year disease-free survival rate was 87.5%. There were three instances of post-transplantation tumor recurrence during follow-up monitoring (median, 17 months; range, 10-22 months), but no deaths occurred. Median survival time from initial diagnosis was 33 months. Four postoperative complications recorded in three patients (anastomotic strictures: portal vein, 2; bile duct, 2) were resolved through radiologic interventions. Using an intensive tumor down-staging protocol of CCRT followed by HAIC, LDLT may be a therapeutic option for selected patients with locally advanced HCC and portal vein tumor thrombosis.

Development of a cyclosporin-A-induced immune tolerant rat model to test marrow allograft cell type effects on bone repair

Bone repair is an important concept in tissue engineering, and the ability to repair bone in hypotrophic conditions such as that of irradiated bone, represents a challenge for this field. Previous studies have shown that a combination of bone marrow and (BCP) was effective to repair irradiated bone. However, the origin and role played by each cell type in bone healing still remains unclear. In order to track the grafted cells, the development of an animal model that is immunotolerant to an allograft of bone marrow would be useful. Furthermore, because the immune system interacts with bone turnover, it is of critical importance to demonstrate that immunosuppressive drugs do not interfere with bone repair. After a preliminary study of immunotolerance, cyclosporin-A was chosen to be used in immunosuppressive therapy. Ten rats were included to observe qualitative and quantitative bone repair 8 days and 6 weeks after the creation of bone defects. The defects were filled with an allograft of bone marrow alone or in association with BCP under immunosuppressive treatment (cyclosporin-A). The results showed that there was no significant interaction of cyclosporin-A with osseous regeneration. The use of this new immunotolerant rat model of bone marrow allograft in future studies will provide insight on how the cells within the bone marrow graft contribute to bone healing, especially in irradiated conditions.

Impact of preoperative radiotherapy on head and neck free flap reconstruction: a report on 429 cases

BACKGROUND

The primary objective of this study was to evaluate the impact of preoperative radiotherapy on the outcomes of head and neck microvascular reconstruction. The secondary objective was to assess the specific effects of irradiation doses (IDs) ≥60 Gy on the outcomes of head and neck microvascular reconstruction.

METHODS

All patients who underwent head and neck free-flap reconstruction in our institution between 2000 and 2010 were included in this retrospective study. A total of 429 patients were enrolled including 136 patients previously irradiated on the head and neck. The impact of preoperative radiotherapy on free-flap success, local and general complications, postoperative mortality, time of decannulation, duration of enteral nutrition and length of stay was assessed in univariate and multivariate analyses.

RESULTS

In multivariate analysis, preoperative radiotherapy (irrespective of ID) was a significant risk factor for fistula formation (p = 0.003) and wound infection (p = 0.005). Previous neck irradiation at doses ≥60 Gy was associated with an increased risk of free-flap failure (p = 0.04), overall local complications (p = 0.05), haematoma (p = 0.04) and longer duration of enteral nutrition (p = 0.006) and hospital stay (p = 0.004).

CONCLUSIONS

Preoperative radiotherapy, particularly for ID ≥ 60 Gy, is one of the main determinants of the outcomes of head and neck microvascular reconstruction.

Radiation treatment effects on the proteome of the tumour microenvironment

Exposure of tumourous tissue to ionizing radiation initiates a wound-healing response involving remodelling of the extracellular microenvironment. The initial reaction involves direct damage to the matrix proteins and the secretion and activation of proteolytic enzymes that lead to local destruction of the extracellular matrix. Subsequently the wounded area may undergo complete repair, may enter a prolonged period of heightened proteolysis, or may overproduce matrix proteins leading to fibrosis. The source of matrix degrading enzymatic activity may be the tumour cells and the tumour stroma. Additional complexity is provided by proteolytic activity released from tissue macrophages, mast cells and by invading inflammatory cells. The local production of growth factors, including VEGF and TGF-β play a key role in coordinating the response. It is anticipated that the application of modern proteomic technologies will reveal hitherto unrecognised levels of complexity in these processes. Hopefully this will lead to the development of new therapeutic strategies to prevent long-term health implications of radiation exposure.

Tissue inhibitor of metalloproteinases in oral squamous cell carcinomas - a therapeutic target?

Matrix metalloproteinases (MMPs) are proteases responsible for remodeling the extracellular matrix (ECM) and enabling spreading and metastasis of tumor cells, a common phenomenon in oral squamous cell carcinomas (OSCC). They are strongly blocked by several inhibitors, among which we must highlight, for their specificity and potency, the endogenous tissue inhibitors of metalloproteinases (TIMP-1, -2, -3 and -4). The goal of this paper is to describe the expression of TIMPs in OSCC, determining their relation with clinical, histological and prognostic factors, delving into OSCC regulation mechanisms and discussing the use of exogenous TIMPs to treat this type of tumors. Expression of TIMPs in OSCC is higher in tumors than in normal tissue, which correlates with an increase of metastatic risk and regional lymph node affectation. Although some metalloproteinases inhibitors (MMIs) have shown promising results in the treatment of these tumors, their use in OSCC has not been widely tested; and although some indirect MMIs, like COX-2 inhibitors, flavonoids and endostatin seem to have beneficial effects on the invasive capacity of OSCC through regulation of MMPs and TIMP levels, routine clinical use has not been accepted yet.

Anastomotic complications after Ivor Lewis esophagectomy in patients treated with neoadjuvant chemoradiation are related to radiation dose to the gastric fundus

PURPOSE

Neoadjuvant chemoradiation (CRT) is increasingly used in locally advanced esophageal cancer. Some studies have suggested that CRT results in increased surgical morbidity. We assessed the influence of CRT on anastomotic complications in a cohort of patients who underwent CRT followed by Ivor Lewis esophagectomy.

PATIENTS AND METHODS

Clinical and pathologic data were collected from all patients treated with neoadjuvant CRT (36 Gy combined with 5-fluorouracil and cisplatin) followed by Ivor Lewis esophagectomy. On the radiotherapy (RT) planning computed tomography scans, normal tissue volumes were drawn encompassing the proximal esophageal region and the gastric fundus. Within these volumes, dose-volume histograms were analyzed to generate the total dose to 50% of the volume (D(50)). We studied the ability of the D(50) to predict anastomotic complications (leakage, ischemia, or stenosis). Dose limits were derived using receiver operating characteristics analysis.

RESULTS

Fifty-four patients were available for analysis. RT resulted in either T or N downstaging in 51% of patients; complete pathologic response was achieved in 11%. In-hospital mortality was 5.4%, and major morbidity occurred in 36% of patients. Anastomotic complications (AC) developed in 7 patients (13%). No significant influence of the D(50) on the proximal esophagus was noted on the anastomotic complication rate. The median D(50) on the gastric fundus, however, was 33 Gy in patients with AC and 18 Gy in patients without AC (p = 0.024). Using receiver operating characteristics analysis, the D(50) limit on the gastric fundus was defined as 29 Gy.

CONCLUSIONS

In patients undergoing neoadjuvant CRT followed by Ivor Lewis esophagectomy, the incidence of AC is related to the RT dose on the gastric fundus but not to the dose received by the proximal esophagus. When planning preoperative RT, efforts should be made to limit the median dose on the gastric fundus to 29 Gy with a V(30) below 40%.

Osteosarcomas of the mandible: are they different from other tumor sites?

BACKGROUND

Osteosarcomas of the mandible (MOS) affect 1/10 million persons/year, mostly the young adult. Due to lack of specific data, the treatment of MOS is extrapolated from that of extragnathic OS but varies widely between institutions.

MATERIALS AND METHODS

We aimed at providing a focused description of MOS histologies and grades through the English literature, at determining the evidence-based role of chemotherapy, of adjuvant radiation therapy and the potential of reconstructive surgery tailored through modern pre-operative multi-modal imaging.

RESULTS

The estimated proportion of high grade MOS was 58%. However, low-grade MOS may be underestimated as they are mostly reported as case reports. The intermediate grade was hardly found in the literature. Estimated weighted-mean proportions of chondroblastic and osteoblastic MOS were 37% and 46%, respectively. Multimodal imaging modalities including MRI has a great potential for accurate pre-operative assessment of tumor extensions into bone and soft tissues. Surgery is the mainstay of treatment and margins the most important factor. The role of neoadjuvant chemotherapy in treating occult systemic metastases and in increasing the probability of clear margins is controversial, as well as the histology-dependent response to chemotherapy. The role of adjuvant radiotherapy (mostly proposed for positive margins) and/or adjuvant chemotherapy is still controversial. Crude survival is around 77% and local control around 67%. Local failure is the main cause of death in MOS compared to extragnathic sites.

Multivariate analysis of the influence of patient-, tumor-, and management-related factors on the outcome of surgical therapy for facial basal-cell carcinoma

PURPOSE

This retrospective, case-control study aimed at evaluating the influence of patient-, tumor-, and management-related factors on the outcome of surgical therapy for facial basal-cell carcinoma (BCC) employing a multivariate analysis.

METHODS

One hundred one patients who underwent ablative surgery for BCC of the face at the Department of Oral and Maxillofacial Surgery/ Plastic Surgery, University Hospital Jena, between April 2005 and January 2009, were analyzed. Patients' charts were screened for anamnestic features as well as management- and follow-up-related details. Standardized photographs were subjected to an esthetic evaluation. Logistic regression was used to identify factors associated with postsurgical wound healing disorders, recurrence, and esthetic impairment.

RESULTS

Following surgical BCC treatment, age and tumor location in the area of the eyes, nose, lips, and ears were independent predictors of wound healing disorders. Tumor location in the area of the eyes, nose, lips, and ears, subtype and class were independent predictors of recurrence. Female gender and location in the area of the eyes, nose, lips, and ears were independent predictors of esthetic impairment. Micrographic surgery and distant reconstruction technique were management-related predictors of wound healing disorders and esthetic outcome, respectively.

CONCLUSIONS

The identified negative predictors of treatment outcome should be included in the informed consent to objectify the patient's preoperative expectations.

Late changes in cutaneous gene expression patterns after adjuvant treatment of oral squamous cell carcinoma (OSCC) by radiation therapy

OBJECTIVE

The objective of this study was to investigate radiation-induced late changes in cutaneous gene expression using a microarray platform and quantitative, real-time, reverse-transcriptase polymerase chain reaction (RT-PCR) validation.

STUDY DESIGN

Paired irradiated and nonirradiated skin biopsies were obtained from 19 patients with a history of oral squamous cell carcinoma (OSCC) treated by surgery and adjuvant radiotherapy at the time of secondary corrective surgery. Topic-defined PIQOR (Parallel Identification and Quantification of RNAs) skin microarrays were used to compare gene expression profiles between control and irradiated skin sample in 8 patients. The data were validated for matrixmetalloproteinase (MMP)-1 and tissue-inhibitor of matrixmetalloproteinase (TIMP)-1 by RT-PCR for all patients.

RESULTS

Irradiation markedly enhanced the expression of molecules associated with the transforming growth factor (TGF)-beta(1) signaling pathway, blood vessel development, as well as extracellular matrix constitution and turn-over.

CONCLUSIONS

Our data suggest that radiation-induced late changes in cutaneous gene expression mainly affect molecules related to extracellular matrix (ECM)-constitution and-remodeling.